Be sure to check out Matt discussing nuclear fusion on "How Sun Mythologies Are Universal" over on Fate & Fabled and tell them (politely) that Space Time sent you! czcams.com/video/utJZ8YmXOnc/video.html
I'm thinking that any alien that tried to reach us would cause a Planet of the Apes / Interstellar scenario where by the time they got here it would be much later into the future for us, relatively speaking.
Check out a scientific paper titled "Migrating extraterrestrial civilizations and interstellar colonization: implications for SETI and SETA" published by International Journal of Astrobiology, Cambridge University Press. It discusses how extraterrestrial civilizations may travel from their home worlds to the Solar System and other planetary systems.
FYI: A phrase is not a question just because you marked it as such. Please review your title, it is not a question. Does this phrase sufficiently exemplify the inverse of my point. Great?
From the SETI website: "If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth? In general, no."
This is a point. Broadcast signals degenerate over interstellar distances. As I understand it, after about 40 or 50 lightyears, the signal would degenerate so much to be hardly perceptible at all; it'd be drowned out by background noise. Now, a strong enough signal, or a highly focused signal might make it, but you'd have to know exactly where to send the signal, and assume the intended recipient would know exactly where to look to find it.
We've only been broadcasting ourselves into space for a relatively short time anyhow. In addition to the generally low power level of those broadcasts.
One bias not mentioned is our assumption of habitable planets. What about habitable moons?! Wouldn’t a high metalocity system include an abundance of moons? Would they be susceptible to the same problems or protected by their host planet?
That's a very good point. Say that a G0 star (which is just a tad massive and brighter than the sun ) have a high metalicity, and therefore is populated by a brown dwarf companion (Sol is a outlier for being alone, actually, and that might be another factor for life, who knows) and has five gas giants, and at least 3 of them have the conditions for life in their moons (Say that one moon is earth-like, one is like Europa and other is like Titan)
Moons are smaller and thefor will have a much smaller magnetic field and it would last for much less time. Also the lack of atmospheric pressure would make water difficult to stay liquid.
@@eligoldman9200 Ganymede is 41% the size of earth and is more protected by Jupiter's magnetic field than Earth is protected by it's own. Venus is only 5/6th the mass of Earth, yet it's atmospheric pressure is 95 times higher than on earth. So between those three facts it is entirely possible that a system with many gas giants could have a moon that could support life.
Are there NO moons out there that aren't roughly earth sized? Surely with the scale of some gas giants, they would pull in more moon and satellite material.
There are so many variables to this aspect that it's mind boggling. There could have been intelligent life a million years older than that on Earth that was wiped out by a meteor. Or life just starting on a planet because it recently (in a glactic sense) moved into a habitable zone. Etc. We could be the first intelligent life in our area. We just don't know. However, I've said this before, and I'll say it again - the moment we landed on the moon, aliens became real. :)
We do have enough of an idea of Earth's past so assert with confidence that there's never been a humanoid species that ever became as technologically advanced as us. Such technology would've survived in at least some form for eventual discovery, considering biological decay is so slow, sometimes not at all. Also there's no evidence of an extinction-event meteor after the dinosaurs-extinction one, since the primary way we know about that is a layer or iridium that's rare on Earth but common and asteroids in the fossil record, plus a great difference in fossils before and after, that doesn't show in the fossil record in anywhere near the same degree since.
@@PoochieCollins You are correct in saying we are the most technologically advanced...on Earth. However, we aren't talking about life just on Earth though. We're talking about life in the solar system, galaxy and/or the universe.
I agree. They’re could’ve been civilizations like 3 billion years ago, and thousands since. There could be tons right now, way behind us or way ahead of us. And there could be millions more in the coming billions of years. We have no idea. Even if there was just ONE civilization per galaxy then there would be 2 trillion civilizations. MIND BOGGLING
If not for the late, heavy bombardment, we may not have had enough metals and other elements that are essential for technology as we know it. I wonder, of all the other earthlike planets, how many actually have a high enough abundance of the proper raw materials within the grasp of the planet's intelligent inhabitants.
Good question, but again it's just an unimaginable scale of numbers. Out of the billions of possible planets, are the odds truly so low that only a handful would have had enough? And that then those handfuls that came before us haven't made their presence known in the hundreds of millions of years they might've had? It's entirely possible we're just extremely lucky. it makes me think of the antrhopic principle. That said, the numbers are just too vast imo. The rare earth hypothesis just seems so uncompelling to me.
What about things like gravity? What if a planet has such a dense atmosphere nothing living on the ground has ever seen a star or even their own Sun? So they never even think to explore outside of what they know? What if they can see the stars but gravity is so heavy, it is impossible to reach orbit? There's a lot to be said about living in 1G with a relatively clear atmosphere.
There are a number of things that need to happen in order for "us" to arrive... From Theia slamming into the primordial planet and creating our Moon while increasing our planets core by almost half again. The larger core gave us a very strong dynamo to withstand the sun's wind and block radiation. This same Moon slowing the spin down with gravity while causing the tidal pools that will harbor the first life . Mars wasn't so lucky and when its core solidified, the solar wind blew its atmosphere into space. The Late Heavy Bombardment restocked the Earth's upper crust with literally billions of tons of metals. Almost all of the original metals were subducted into the core while the planet was molten. Canada had to have been smacked really good with a huge Nickel-Iron meteor which gave it the vast mineral resources it has today.
@@liberalrationalist8905 Agreed, but it's the composition of the incoming meteors that determine what you get as far as metals. The metallicity of the original star cloud determines that.
"Most of us have never seen aliens" Always good to start a science video with a laugh. 😂 About the Fermi paradox, I think it's only a paradox if you're searching for solar conditions that will allow for life but if you're thinking about intelligent life and galactic civilization then you have to account for planetary and evolutionary conditions. My understanding is that from an evolutionary perspective the emergence of intelligence is a path dependent process. Which means that a finite number of paths that lead to intelligence will be practically zero percent of the space of possibilities of the evolution paths. Great video as always, btw!
I don't know man. There will always be trees (presuming terrestrial life and photosynthesis). There will always be monkeys inhabiting those trees, with great spatio-temporal intelligence. And they could always leave the trees freeing up their hands. And they are usually social. This, I'd hypothesize, is a fairly typical path to intelligence. I don't see this as a niche that remains empty for long unless you had say dinos keeping mammals small. My guess is that the great filter probably lies in front of us with various kinds of existential civilizational risks.
@@sharif1306 That's a very big supposition. Complex life on land existed for hundreds of millions of years without complex intelligence evolving. There were no intelligent, tool-using Dinosaurs. Without the mass extinction at the K-T boundary, mammals would not have been able to expand into the open niches and take over the planet. In fact, there is a lot of evidence that long-term "locking" of niches occurs, where things settle into local maximums that are semi-optimal but nothing else can evolve because the niches are full, even if other body plans would be better. Mass-extinctions may be necessary to "shake up" evolution. It's essentially re-rolling the dice on all the ecosystems and getting a new local maximum. This happened quite a few times before humans evolved by chance to be intelligent enough to create a paradigm shift. On planets that are too stable, this might not occur enough and they just languish with poor local maximums and niches filled with low-intelligence animals. But if you have too much destruction, then the mass extinctions might also preclude complex intelligence. There are lots of examples that indicate that Earth is "fine tuned" for intelligent life to develop here, and that its past was "lucky". This is all the result of the Anthropic Principle though. Of course Earth is fine tuned for intelligent life to develop here; if it wasn't then intelligent life would not be here to observe it.
@@insertphrasehere15 I believe the anthropic principle speaks to the physical laws of our universe rather than any particular place in it. But I see your point. I was just alluding to the conduciveness of the tree dwelling niche to the development of spatial and general intelligence abilities. Even our brain is mostly just a scaled up primate brain according to recent work. In any case, as Jesus said, "The meek shall inherit the earth" - thanks to that fortuitous cataclysm bearing down on earth 65 millions ago having been disturbed from its abode in the OORT cloud further back in time.
The standing assumption in science appears to be none of us have seen aliens, despite testimonials, video or radar evidence. But what if that assumption is wrong? What if some of us _have_ seen aliens and just can't convince the rest of us because of social norms? Shouldn't we actually investigate UAPs before trivially rejecting them? There is a lot more which could be done in this area.
i like to believe that life is still pretty common in a relative sense in the galaxy, but one thing that needs to be considered is the window where life is alive. humans have only been around for a short period of time on a universal scale, and that means that maybe detectable life was around before we were here or maybe after we are gone.
Why do you 'like' to believe that? Wouldn't that mean intelligent advanced life rapidly dies out before colonizing the galaxy? I would find our chances much better if intelligent life was some kind of incredibly unlikely occurrence.
It has also been proposed that one of the greatest limiting factors to the formation of life is the presence of Phosphorus. Phosphorus is created from supernovae. Thus we need a sufficient enough number of supernovae events to have occurred to allow a chance for life to begin. We also need to have that Phosphorus become concentrated enough in certain regions of the Galaxy to allow for Phosphorus-enriched star systems to form.
So far, we've only really been able to make educated guesses about alien life of any kind up till now. So many pros and cons to consider. Most people end up tying themselves in knots trying to fathom some answers. Hopefully JWST will help shed some light on this subject over the next few years.
@@chuckschillingvideos I think people really overestimate the amount of systems we could've realistically looked at by now, it's very confusing to me how someone could genuinely believe the fermi paradox is a paradox when there's 100 billion galaxies and within our lifetimes there's no chance we can even actually analyze .0001% of a single galaxy. It almost seems comically idiotic to assume we'd have found aliens easily yet that's what everyone assumes for some reason. If we're being entirely honest we're not even really capable of searching yet.
@@erdelegy Those are guesses, that do nothing to remove guesswork. Fleshy fingers to manipulate tools? Is that serious? I can think of a half dozen different and very capable methods of manipulation, and I am hardly an authority.
@@chuckschillingvideos Look at the Cool Worlds channel I'd say there's substantial statistics and math involved in this educated guess. The problem is of course we only have a single sample.
@@chuckschillingvideos I think you're being very unfair. Scientists have predicted all sorts correctly. From gravitational waves to hydrocarbons flowing like water on Titan. But there's always that surprise that nobody saw coming. Now we have JWST just around the corner from science work. No speculation went into that at all. It's been perfect throughout.
The moon being so large (tidal energy extends the life of our metal core) and mix of land and water are probably rare being in the habitable zone of our star type. We also are almost as large as we could be and still get off the planet via rockets, giving us the gravity to maintain an atmosphere while still being able to escape.
i think you can escape a planet with a couple of multiples of earths gravity, you just need to develop a more energy dense fuel than we needed to first. might take a good while tho.
There is also the fact that the Earth is not just any rocky planet. Earth has an unusually large, metal-rich core which generates a robust magnetosphere which protects the atmosphere. Mars doesn’t have a robust magnetosphere, and so lost a bunch of it’s atmosphere over time. Even Venus is slowly bleeding armosphere, it just that it is so thick that it remains cloaked even after a planet like Mars has lost the ability to retain liquid water.
I still feel like the most reasonable resolution to the Fermi paradox is "no civilization ever develops to the point where we could detect them with our current 'primitive' methods". Which I guess includes no civilization ever making Von Neumann probes for one reason or another.
Someone pointed out a interesting fact. We as a species are becoming silent. Before we would podcast signals through radio waves all across the planet but now most of our communication are in hardlines buried under the ground. Even something as basic as music and news are now mostly streaming online or being downloaded as a podcast in MP3 format. Couple more decades and we may not be broadcasting anything. That happened within only a 50-year time span. Now we are talking about communicating with lasers.
I wonder. We think in terms of unlimited expansion and expanding resource consumption. Maybe this mindset is a phase of early development. Then civilizations find it not worth the bother or something. Island cultures have learned to cultivate resources, the hard way, several times. Existence in a steady state can be achieved and flourish, taking the long view and allowing for generations ahead. Like homeostasis as opposed to cancer. And the grown-up aliens are just hangin, enjoying existence. Quiet and balanced is good.
@@MrJimbissle That! And maybe through vast amount of time individuals of that civilization can acquire unimaginable senses thorough which they can percieve universe non locally.
The more I think about it, the more I wonder if maybe the solution to the Fermi paradox is just that we really happen to be one of the first intelligent species to evolve. It sounded ridiculous to me at first but there are just so many parameters that had to go right. Mostly on the front of biological evolution though. It took so long just to get eukaryotic cells
I don’t think so. Intelligence can develop a lot of other ways and can not resemble humanity’s style. If you like sci-fi and reading - check Peter Watts and his novel Blindsight. That’s a good book and interesting view about alien lifeforms
If you throw dices of 20 faces what are the chances of getting 2 twenties in a row? one in 400. And 3 in a row? one in 8000. And 7 in a row? one in 1.28 billion. And 10 in a row? One in 10 trillion. Meaning, if there's only 10 conditions that must be met and those have an independent chance of happening of 5% (like only 5% of the stars are the proper size, only 5% of the planets can hold life, only 5% of the galaxy is habitable, only 5% of the planets are old enough for life to develop, etc, etc, etc), you already need on average 10 milky ways to have one single planet hosting life. The magic of multiplication and exponential functions.
I don’t think it’s a matter of intelligence. Dolphins are maybe as smart as we are, but living in water they’re never going to develop technology. We might end up finding a bunch of intelligent dolphin like aliens who were never able to develop technology because of their environment and biological limitations.
Simple solution is there are billions of earth like planets but they are so far away that we have no contact. Even at the speed of light it would take hundreds or thousands of years. And you would need an insane number of probes to cover all that space. But also we have solid evidence of alien encounters, alien technology, ufos etc which are just ignored by mainstream science
Wouldn't more heavy elements, thus producing more gas giants around stars, also mean increased chances of exomoons in the habitable zone? The bounds of the galactic habitable zone are there, but perhaps they're fuzzy, with gradients of other possibilities.
I think moons around gas giants are more difficult to detect. You'd have to essentially do the exoplanet detection thing squared. Maybe the lack of detectable information is biasing the extrapolations. Until there is data on the existence of gas giant exo-planet moons (though by any reasonable thought there should be many) they are not considered as part of the running theory. Similar to how it was "shocking" when exo-planets were confirmed and in such large quantities, even though any casual thinking on it should have made their existence not a surprise.
The moons of gas giants tend to be relative cool (which also slows down every chemical reaction), and there is also a lot of radiation. Not the best conditions for the development of complex or even intelligent live.
That is an important question. Some scientists believe there are as many habitable exomoons orbiting gas giants as habitable exoplanets in our galaxy. If there are more gas giants in the center, the higher number of habitable exomoons may offset the lack of habitable exoplanets.
@@wolfgangkranek376 These are examples specific to our solar system, where the gas giants are well beyond the habitable zone. Imagine Jupiter in Mars' orbit! There are known gas-giant exoplanets in similar orbits.
@@ckl9390 You're quite right, scientists have to deal in hard data and models that successfully predict the observed results. We've all of maybe two exomoon candidates detected, though the field is fascination as a visit to the Cool Worlds channel here on CZcams will show.
It's just both surprising and somewhat amazing to me to see Matt getting older in every new episode. Can't believe it's been more than 5 years with him, and the change is astonishing. He's only getting much more genius than he ever was every day.
Glad I wasn't the only one who thought that. I was actually a little concerned since I typically only listen while I'm driving and don't usually see him that clearly.
“A fire upon the deep” by Vernon Vinge explores an intriguing twist on galactic physics - where the laws of physics are subtly different the closer or farther to the Milky Way core you go. As a result different technologies are needed at different levels, and even biological cognition is affected.
@@reesetorwad8346 Science-Fans, please know: One of the most Empathic Videos i ever saw just came out: "Why do I Care?' by 'Belief It Or Not'. Together with the GOP-Videos of 'Some More News', its quite amazing and best coverage of the Attack on Woman-Rights and other things, i know. For those who wanna be updated and those that have Empathy (a combinttion that will make you wanna know about the current Abortion-Right Chaos), this is for you.
After having studied evolutionary development on earth a great deal, my current hypothesis for a great filter is atmospheric oxygenation. From our current understanding of the evolution of photosynthesis, turning sunlight into biologically available energy occurred multiple times in different organisms, of which chlorophyll is only one option. In fact, there is a hypothesis that chlorophyll (and thus plants) are green because the developed in the shadow of purple photosynthetic bacteria (which are still extant), where no green light would be, so they developed to absorb the remaining red-blue light. The interesting thing about chlorophyll however, is one of its waste products: elemental oxygen. To most life at them time, oxygen was toxic as it is so affective at oxidizing chemicals that it would interfere with its metabolism. But a few lucky organisms were able to use it to make use of it to develop far more efficient catabolism. Anything that you would call complex life, eukaryotic or multicellular, uses aerobic respiration (or had aerobic ancestors and secondarily lost their aerobic abilities). It is likely that without the over abundance of such a powerful oxidizer in our atmosphere, life would be relegated to unicellular prokaryotes. So if another planet forms it’s own life forms, and their main way of synthesizing energy doesn’t create such a reactive byproduct, would complex life be able to evolve as often. Of course, this is just my thoughts. I just want to get this idea I had to somebody who is actually looking into the great filter, since I’ve never seen it talked about in these discussion. As always more research is needed. Edit: I corrected my backwards explanation of color absorption in photosynthesis. Green plants reflect green light, absorb red and blue. It doesn’t change the whole thing, but I did see that many in the comments got held up on this admittedly incorrect fact and I apologize for my lack of in-depth reviewing of my internet comment.
Remember that colored pigments like Chlorphyl are the olor they are because they DON’T absorb much of that wavelength, they reflect it instead. So the purple bacteria didn’t absorbs most wavelengths of light, including green. and Chlorophyl absorbs most wavelengths, including purple, but _not_ green.
I have read that one reason chlorophyl might be so common even though it dosen’t absorb one of the more abundant wavelengths of light (green) is precisely because of the abundance of green light. If plants tried to absorb as much green light as possible, they would absorb too much energy resulting in damage their cells. This is why green-absorbing pigments like red, brown, and yellow are produced in only limited amounts.
This would be interesting because if your hypothesis is right, we should still see biospheres on other planets. Just not Oxygen based ones. So if this is correct, it assumes life isn't that rare, but Oxygen based life/atmospheres are. Of course, there are still billions of potential planets out there, with who knows how many chances for life like this to form, so it's still a numbers game. But your idea should be at least testable when/if we can ever get spectrogram readings from exoplanets.
Oxygen is ridiculously abundant in the universe, behind only hydrogen and helium. So it's probably not much of a bottleneck, especially if it's so beneficial to simple early plant life.
One correction: most photosynthesis involves visible light. Some UV is involved, but plants can thrive just fine on artificial lighting that does not include any UV. Plants do absorb a lot of blue light though, so a sufficiently cool red dwarf might still be a problem.
@@sitfish1113 they are black because they need to absorb all the light they can get whilst emitting as much heat as they can, so most likely they will look black. Brown is prossible too but that means they must have an alternative that somehow makes them absorb light more efficiently if brown is the case. Especially with atmospheric scattering of light, there wont be much light energy to begin with. Very likely they'd switch to a mixture of both chemosynthesis and photosynthesis. Or maybe they use heat catalysed reactions, and exploit heat directly.
Videos like this made me wonder, if us humans manage by some miracle develop FTL travel, and find a primitive civilization, would we protect them? Or doom them?
Could a significant portion of even the sun-like stars in the habitable zone of the Milky Way be ruled out due to being in globular clusters, where radiation and perturbance is more likely? Or maybe those are mostly already not in the habitable zone?
Even if they are in globular clusters, there would be far enough that the radiation from other stars won't reach them as in most of it would have dissipated before it reached the planet or star system.
there is a chance life could exist in a globular cluster but its unlikely as the stars are much closer together. so that could mean a planet could get ejected from the system by another star or be destroyed if a nearby star goes supernova.
Here is my opinion on it based on all the space videos I watch: To become a planet you are stealing a bulge away which would have otherwise ended up in the main star. To become a bulge you need a headstart and heavier element are more likely to provide that headstart. More the heavier elements away from main star bulge it would result more planetary objects. And collision between them would form bigger planets. Again just my guess.
Science nerd opinion, not professional opinion: Amit hit on one key - the more "heavy" elements, the more planetesimals can form, thus more heavy planets. Equally important, among those heavy elements is a greater abundance of iron, which provides atmospheric protection with a magnetic field. In addition, the magnetic field of the star will tend to draw more ferromagnetic element inward, meaning the planets forming in the outer edge of the "terrestrial" zone are likely to get to the size needed to become gas giants. This will disrupt terrestrial planet formation.
Metallicity simply refers to the amount of material that is heavier than hydrogen and helium. In the core accretion theory, gas giants such as Jupiter and Saturn first had to obtain cores of roughly 10 earth masses before they could start accumulating hydrogen and helium. More material around a star would lead to these planets forming in a shorter time frame. Once one or more gas giants are established, they can dictate the growth of smaller planets as they migrate towards and away from the host star.
@@AdamBoozer That doesn't explain it. Metallicity measures the fraction of total mass that's heavier elements. It doesn't tell you anything about the total AMOUNT of such systems - in other words, their "mass". You can for example have high metallicity in a low-mass protoplanetary system (say around a recently-formed red dwarf system) and low metallicity in a high-mass system (e.g. around first or second generation giant stars).
Honestly, I think the Fermi Paradox can be entirely explained by the vastness of space and the slow speed of light compared to the size of the universe or even galaxy. I think even scientists seem to somehow underestimate the huge distances and the vastness of space. Even if our galaxy contained life which is on the same technological level as ours, we wouldnt be able to detect it. Our own "radio bubble" just barely stretches out what, like 100 light years? And the signal is probably so weak by that distance that it is basically impossible to detect. We just started detecting the first exoplanets the last couple of decades.. and they are all very close to us in galactic dimensions. Space is just too big and everything is too far apart for us to ever detect alien life. This applies to our galaxy. Other galaxies are even more unlikely to be accessed by any of our sensors, and we certainly will never be able to travel there. Can anyone make a good rebuttal to my arguments? I am genuinely curious if I have a thought error here.
Your argument is reasonable but not ironclad, due to the antiquity of the universe. At our current level of technology and progress, unimpeded by extinction, we should be able to colonize the galaxy in about ten million years. The Milky Way is far more ancient and has had enough time preceding our solar system for this to have already happened. But your ideas are valid and probably contribute to the solution to the paradox.
This is exactly what I’ve always thought. Even if there were super advanced civilizations out there I still think the massive distance between us makes it physically impossible for them to reach us and vice versa. It’s a bummer to think we likely will never learn about other life out there but it’s cool to be so sure that there is.
Check out a paper "Migrating extraterrestrial civilizations and interstellar colonization: implications for SETI and SETA" published by International Journal of Astrobiology, Cambridge University Press. It discusses how extraterrestrial civilizations may travel from their home worlds to the Solar System and other planetary systems.
Your description of the sun being an "ordinary" G-type reminded me of a paper published within the last year. It detailed a study of the activity of around 20 G-type stars, having approximately the same age of the sun, over a few years and found that the sun was far less active than any of those observed. Hardly a smoking gun as, while we have a few centuries of sun spot data to directly support the sun's activity and other methods to indirectly support it (e.g. ice cores etc) compared to only a few years of data for the other stars. Combine this with the observations being only a flash in the pan compared to the age of the stars and the fact that only a relatively small population of G-type stars were studies, and the results are of tenuous importance. However, the study may be the first to show evidence of the tantalising theory that our sun is also unusual and played a big part of our success. I also believe that even prior to that study it had been a long standing hypothesis that our sun may be underactive compared to the majority from observations of a diverse range of stars being more active than sleepy ol' Sol.
@@amit53shukla I don't think that is it but I'm no expert. The activity they are trying to measure is that of the stellar wind events driven largely by stellar magnetic fields near the surface of the stars (e.g. flares, coronal mass ejections). The stars are far brighter than any ejections so their visibility doesn't change much. In fact, I think they might be slightly darker. This is very different to the "activity" of neutron stars and black holes which can become immensely brighter when active. From memory the study looked at the number and/or the percentage of surface coverage of sun spots on the 20+ G-type stars. From observing the sun we're quite sure that flare etc. activity is proportional to sun spot activity. The main issue with drawing any solid conclusions using that study is it's relatively short length (2-3 years from memory) compared to the huge lifetimes of the stars and small sample size. For comparison, the milky way is estimated to have approximately 20 billion G-type main sequence stars from a quick google search. Ultimately we have only recently been able to start observing other stars in high enough detail to make these observations and it will take many future observations (and probably increased automated data analysis if you want to scale it up to millions of starts) to confirm/ refute these observations.
@@aarongoodwin4845 That's not quite how it works. The "activity" is stellar weather, large emissions of charged particles accelerated to high speeds and these literally erode the atmospheres of planets. The activity doesn't correlate to the radiative emission of a star in a linear fashion i.e. it could be a relatively cool star so liquid water could only form close, but, it may also have awful storms that strip any planets in the habitable zone of atmosphere. In fact some of the most active stars observed are relatively cool with red dwarfs being very active for at least a few billion years. It is hypothesized (using computer models) that this activity will decline with age but that's on time scales close to the age of the universe so it is difficult to confirm as none that we can observe easily are near that age. That is one of the reasons most astronomers believe red dwarfs are unlikely to be habitable, in combination with the necessarily close orbits causing tidal locking, any terrestrial planets will certainly have their atmospheres stripped like Mercury. Disclaimer though, when discussing the "habitable zone", astronomers are only speaking about Earth-like habitability. The likelihood that we will find other life outside of the habitable zones is still very high. It is just unlikely to resemble life on the Earth's surface but may be closer to deep ocean life on ice worlds or something we can't even imagine. We focus on Earth-like life simply because we can't reliably predict what to look for otherwise as we have no examples to base any assumptions on. We are still looking though but it is more difficult not knowing what to look for.
the moment moya's name got mentioned all i could think about was farscape living ship moya intro plays "my name is john chrython an astronaut,radiation wave hit and i got shot through a wormhole,now im lost in some distant part of the universe on a ship,a living ship full of strange alien life forms,im being hunted by an insane military comander and im doing everything i can,im just looking for a way home
If the estimate of 200 trillion galaxies is correct, then advanced life could be as rare as only one species per one *billion* galaxies, but that would still mean theres 200,000 forms of advanced life, but would be so far spread out that our likelihood of finding it is virtually nill. I dont think the Fermi Paradox is really a paradox, I think its simply our brains inability to fathom a universe so large, that even if well populated, would look completely barren to us.
This only works if you assume habitable planets and abiogenesis are /extremely/ rare. In which case, you then have to answer /why/ it's so extremely rare. Your example doesn't really work. The numbers are just too obscene. The problem with your argument is that it assumes Earth/Life is special. **Why** is life special then? You haven't really answered the Fermi Paradox. All you've done is move the great filter to abiogenesis or some other early process. I don't think you understand what the Fermi Paradox is if that's your argument. The Paradox doesn't say there has to be alien life out there and that we just don't see it, all the paradox asks is why there is no other life we've noticed yet. Either Earth is extremely rare (and we know planets like it aren't), abiogenesis is extremely rare (we don't know), intelligent life is rare, or there is some great filter that every technologically advanced civilization encounters that prevents it from becoming galactically known. All you've done is moved it (the filter) from the last option to the one in the middle. Which is one scientists are already contemplating. And I really want to drive home that the odds of life forming are independent from how many galaxies there are. The difficulty/rarity of life is independent of it. If you have a million coins and flip them all, the odds of getting heads or tails on one coin is still 50/50, adding more coins doesn't change that. Same here, adding more galaxies doesn't make the formation of life less rare in your example. The odds of life forming would still be astronomically low. Basically, why is life so rare? That *is* the Fermi Paradox. You're literally just describing another version of it. You just so happen to believe that life forming at all being rare is the answer. Edit: not to mention that "well populated" is doing an incredible amount of heavy lifting in that thought. It's only ""well populated"" because you think 200,000 is a big number. If only 1 in 10^9 galaxies has any kind of life in it whatsoever, I wouldn't call that well populated. That's very very sparsely populated.
I think that the idea of the Great Filter should be seen as a number of filters, each stage decreasing the chances for that particular planet to bear intelligent life. The chances for intelligent life as we know it to evolve must be astronomical.
Given our past record of predicting what's out there it seems improving able we would guess this one or be able to confirm it. Space is really big. I mean really big.
@@nexaentertainment2764 I dont think abiogenesis is rare, I'd be willing to bet simple life starts wherever its possible, I wouldnt be surprised if we find it in the waters of Europa or Enceladus . That simple life being able to evolve into something advanced like us could be quite rare though, simply due to the sheer number of specific things that likely have to occur to make that happen, but again in a universe this big, with as many possibilities over as many years, rare becomes a bit relative (200,000 is big compared to 1).
Is it true that Earth’s moon could potentially me the reason why life was able to emerge on Earth? It’s rare for an Earth-like planet to have a moon as big as our own, and we only got ours from some sort of perfect collision. Could the way it affects Earth’s orbit and rotation and tides somehow be the key that explains how life could only emerge here?
I was thinking of this the entire time myself. I remember hearing that the moons stabilizing effect on the Earth may have been integral to the development of life here.
Yeah the moon is super rare, it's essentially an extra planet that earth captured during planetary formation, and the exact sizing and energies required that resulted in a stable system without it ripping apart or ejecting are colossally rare. We also know the moon is integral for early life formation, and many view it as a great filter for very early life formation
I recall from my youth an essay by Isaac Asimov where he explored this theory: that only a planet in a sun's habitable zones AND with a massive moon might be able to support life.
Space Time got an episode on that, that'd fall under the Rare Earth Hypothesis, and yes the massive moon is a significant factor in that hypothesis due to it being massive enough to form tidal pools
How do the spiral arms affect galactic habitability? I mean, if the core is problematic for being too star-dense & outskirts for being too matter-sparse, should have lesser versions of same issues depending on whether you're closer to an arm's "spine" or to being out in the "empty" areas between arms. As well, what's current best guess on layout of dark matter in galaxy, and how IT might disrupt habitability?
It's been 2 years, but the Milky Way has LESS dark matter than normal. Usually they get disperse by collisions, and we have a some dwarf galaxies that orbit and collide with us. Even if dark matter has 0 interaction for fusion, it's gravity could cause stars to crunch harder, and burn more violently. I'm interesting in some of the sparse solar systems in clouds, which surely have some stable suns, without risk of interference... unless debris is necessary to life (note, a massive, massive amount of our metals came from collisions, and the moon)
The Fermi "paradox" is founded on the rather presumptuous notion that life forms can ever have the means and motivation to have the kind of impact on the galaxy that would show up in the night sky. Much more likely shunting around stars for convenience is just not viable, and I'm tired of people pretending otherwise.
I like to think that lots of life has popped up in the habitable zone, and then just goes extinct when the star eventually leaves it, like ours eventually will.
@@theslavegamer That's the point. Life is meaningless because life and the universe will die. It is a very depressing realisation, but the truth. I try not to think about it and try to live happily and be kind to everyone. I think that's the only way to go about it tbh
Question 1: Are there habitable zones at larger scales? Galaxy clusters? Superclusters? Observable universe? Question 2: Has anyone calculated a temporal habitable zone or, better put, habitable time periods for the solar system, galaxy, or universe? A habitable time period would be the window of time during which life may develop, i.e., from the earliest life may originate to the latest it may survive.
I haven't heard of any events that can have an impact on life at the intergalactic level the way supernovas and quasars can impact life on the galactic level. I think, generally speaking, galaxies are exempt from extra galactic conditions affecting their ability to support life. Maybe galactic mergers but even then, as I understand they happen rarely, and aren't that catastrophic so it'd be difficult for that to constantly prevent the emergence of higher life forms. Also, the only thing I've heard regarding question 2 is that life is less likely to form the younger the universe is, and more likely to from the older the universe is. Something about stars having higher metallicity, and there being a greater abundance of elements to form life from as the universe gets older.
The Fermi Paradox is probably solved by something mundane, like phosphor levels, combined with one of the popular ideas about the super rare events in the evolution of life (like the mitochondria becoming apart of another organism).
@@Nukepositive I mean we can't rule out the possibility until we find other civilizations, but it's pretty similar to saying that the universe is empty and we're all that there is. It's arrogant. Humans have always liked to think that we're more special than we are, but we could go extinct today and the universe would go on just the same
@@Nukepositive Yea but then there is this pesky question of why now ? As we heard it, many suitable star precedes our sun, assuming that life emerges with the same rate, we really shouldn't be the first. Then again, this problem is hard because it contains way too many unknown variables.
In another life mitochondria would not be needed. Maybe even oxygen metabolism wouldn't be necessary. In absence of competition from oxygen-using organisms, other type of metabolism may come to the forefront, maybe even some which is impossible in our Earth life. Interesting that you haven't mentioned evolution of oxygenic photosynthesis. I am actually a researcher, and I can say on Earth this evolution was one unlikely event upon another.
Two things. First, there's no surprise at all that we are tightly tuned against our environment, because that is precisely what evolution does. Second, we need to consider not merely great _filters_ but great _alternatives._ Are there other, more favourable, things for life to do than build technological civilisations? We might be “alone” because we're the _unlucky_ ones, who have not thought of, or not been able to achieve, some otherwise obvious alternative(s). Evolution only appears to be directed because of the point from which we view it.
Yes, evolution tends toward an environmental nitch but the environment has to be finely tuned in order for life to develop in the first place. The fine tuning problem cannot be explained by evolution. There are dozens of physical constants that are set perfectly to allow life and if any one of those constants were even a little different life could not have started. So talking about evolution is kind of irrelevant because without a fine tuned environment life could not start it's evolutionary process.
Technology is merely the creation of methods to increase probability of survival. But technology requires (first) communication between individuals: language and (second) communication between generations: writing. Why have primates, over time, increased intellect? Our bodies allowed it. In other mentioned species, increased intellect doesn't add to individual and/or group survival. What could human genius level IQs do to advance elephants, orcas, dolphins, birds, etc.? Our brains could increase in size because our heads sit on top of our bodies. We evolved hands to grasp fruit. Binocular vision to keep from falling out of trees. Non-primate species are too deeply locked in by their biological inheritance to physically change in ways where intellect has advantages. For a non-primate entity capable of using intellect to come about, there would need to be a major catastrophe like that 66 million years ago where genetics could again create new lines of evolution the way mammals which existed during the era of dinosaurs were able to diversify after the KT extinction event. The reason dinosaurs dominated the planet was oxygen levels fell. Dinosaurs, too, were a sideline lifeform alongside mammals, reptiles dominated. But dinosaurs had developed a more efficient breathing methodology than mammals so when oxygen levels fell (down to10-12 percent) dinosaurs could get larger but mammals had to decrease in size just to survive. When oxygen levels returned to normal, dinosaurs were simply too dominant.
@@acetate909 Yes, this is the common argument, but it is almost always approached from the viewpoint of “what is the chance of the fine tuning that _we_ have evolved for” rather than “what is the density of evolution-supporting points in the mathematical parameter space”. I'm not saying that we yet have the mathematical tools to address the latter; merely that the former is fallacious. What proof is offered that other tunings provide no mechanism for evolution?
@@liberalrationalist8905 Doesn't that sound just the teensiest bit racist? You'd only need one friend who's an octopus to persuade you that you don't have to be English to have culture. Um. What I'm trying to say is, you've provided a backstory for yourself, and assumed that this backstory is what makes you superior. But the former idea is merely an emotional justification of the latter idea, not a condition for it.
One issue that's always looming large over "where are the aliens" questions is that we've only searched a teeny, tiny area around our planet. It'd be like being on a very small island, not finding any other life on it, and conclude that there is no other life on the planet.
what we look for are, techno-signatures of super-advanced alien civilizations to which the galaxy seems very devoid of and so we conclude we must be alone in the galaxy otherwise they would have already colonized a huge chunk of the galaxy.
@@fugslayernominee1397 how would we find those signs? If a super advanced alien race exist right now but they are 1000 light year away, and we point our telescope at their location right now we still would not know who they are because any signal that is given off would be from a 1000 year ago.
@@Abluemoon9112 Indirect ways (i.e. there should be type 2 civilization s existing already that should be making Dyson's spheres, meaning also missing or constantly dimming stars. So far, we haven't detected any. Also, Dyson Spheres are so resource intensive that they produce so much radio waves that rival a star. 1 such system should be detectable by seeing a very high radio wave with very low luminosity.
@@Abluemoon9112 Galaxy is more than 13 billion years old and even if we minus first few generations of stars, that still leave us with so many stars that would have spawned an intelligent life if it were this common as spawning every few thousand light years. The whole point being; if intelligent life is so common that it emergence every few thousand light years then what makes them stop advancing any further? If there is an intelligent life in few thousand light years of us and only started giving off techno signatures just now then given geologocal time scales this must be a one heck of coincidence and should suggest intelligent life is a lot more common and we should be detecting these kinds of techno signatures every so often from other parts of the galaxy and from other civilizations that are lot more advanced and older that the one you mentioned, this only makes things worse.
@@skybattler2624 again if a Dyson sphere exist now it does not mean we would see it. We can only see in the past not the present. So an advance alien civilians has to existed in the past for use see it now. A Dyson sphere is also just a hypothetical structure that we as humans think an advance civilization show have.
I think part of the point is that, even if we assume life *always* needs the same conditions it needs on Earth, there's still an ample amount of planets that should be able to fulfill those conditions.
The only life that has to be similar to ours is life that arose in similar conditions to our planet. On a much colder planet, ammonia could end up being a life-solvent instead of water, which leads to completely different habitability concerns.
The thing is : we're really far from taking every parameters into account and I actually think the Fermi Paradox isn't a paradox at all, or at least only if you see it from the perspective of astronomy and physics as we just took the conditions at an astronomical scale for life to emerge but there's so much more to consider. For example, the fact the core of the Earth is liquid AND solid iron allows us to have a strong enough magnetic shield to protect us against the dangerous coronal mass ejection, there also is the fact life took a very long time to create an intelligent species on Earth, about 3.5 billion years (maybe even more, as far as 4.5 billion years), so it's not something we should dismiss as it has its importance into the equation. Assuming, after all of that, there's still suppose to be a lot of life in the galaxy, we didn't mention the possibility of their auto-destruction, which could explain why we didn't see any of them yet, something we may face one day too as an intelligent species. So, there are so much things we have to take into consideration before drawing any conclusion.
@@tim40gabby25 Noo, we're far from it. With the first nuclear weapons appearing, we all feared that in would eventually end up in a massive and world wide nuclear war and we would create a nuclear winter on Earth, which would make the Earth's surface unlivable. So far, nobody shot and was crazy enough to shoot even once on another country or civilians since the incident in Japan with Little Boy (or Fat Man, I never remember), which made us realize the immense power we had in our hands. That was the first cap for a long time we needed to check : see if our level of hostility toward our own species could create an auto-extinction with powerful enough weapons. Now, if you're referring to the global warming, we won't be extinct for that, it's not even a survival challenge for humanity. Though, it is a stick in the wheel of our ambition to constantly want to improve our civilization and our comfort of life.
@@rigierish3807 You describe what has not happened, not what might. 50 years not pressing the button is not a long time period. Are you confident that some person will not press sometime in the next 10,000? 50,000? - both are blinks of an eye in geological time.
@@tim40gabby25 (sorry, I didn't see your answer, I only noticed because there was another comment that popped up in my notifications) I’m pretty confident due to the fact only few decades of observation is necessary. And the reason I'm only considering the first decades is because self-destruction is only a matter of knowledge and the more time passes, the more we have knowledge on a subject. When we first created the ozone hole in the atmosphere because of a component in refridgerator, we made the mistake but realized it later and since then, we started to be more careful of the impact of components we use in our products on the environment. It is very unlikely now that we could make such a mistake considering we know what we are able to do. Nuclear weapons are the same. When we shot the first nuclear weapon, we realized our mistake and how dangerous it can be to use them. As we know the danger of such a weapon, we won't use it anymore and will proceed to be extremely careful with it since this day. When the first nuclear weapon was created, we knew it was powerful but we didn't know how much. Now, we can make simulations of our last most powerful nuclear weapons and we know exactly the extent of our power thanks to it. The more we advance, the more we are afraid of our power as a civilization. That's why the likeliness for it to be used will constantly decrease the more time passes. As crazy as it sounds, the most dangerous times - that is when it was the most likely that another nuclear weapon could be shot - was few years after Little Boy was shot. And indeed, that's what happened because few days after Little Boy was shot, Fat man followed.
See the problem I take with this video is our Star is provably unique on a galactic scale and potentially unique in the observable universe in so that it is abnormally quiet for a star and not just for G type stars but of all star types our special little star produces far less solar flares than most others observed. (Edit: typo)
Surprised that the abnormal quietness of the Sun was not mentioned again in this video. Also that sapient life will rapidly over-run the ecosystem and destroy itself... and even if it doesn't entirely, the next time around there will be no huge "easily accessible" hydrocarbon reserve to tap.
@@dw620 I find it strange because they've done several videos on similar subjects where they have mentioned it and a video dedicated to the quietness of our sun so I'm really confused by this video it contradicts a lot of evidence to argue our star isn't special.
Our star is demonstrably not unique in the galaxy and is not close to being so. It is pleasingly quiet, but there are billions of others of comparable profile. This means the flare level is quite low - what is rare in a population of hundreds of billions is still billions in this case. Keep in mind that our star still produces flares and that flaring at substantially higher levels does not at all rule out the development of life of all kinds.
I think the most likely reason why there is a "Fermi Paradox" is due to the massive distances between stars. It's just mind-blowingly far. Add to that the seemingly "perfect" conditions necessary for carbon-based life with water as an organic solvent (the only type we know works), the time scales required for life to actually advance to "intelligence" (which took billions of years on Earth), and the fact that just because a species could spend a million years sending probes around the galaxy doesn't mean it will see any good reason to may not give any answer to whether intelligent life exists, but may give a good idea of why intelligent life has never been detected outside of Earth. When it comes to this galactic habitable zone, I am curious what it looks like a billion years ago? Two billion? It should shrink quite a bit going back in time. It's entirely possible that Intelligent life has only had less than a billion years to pop up anywhere in the Milky Way when all other variables are considered, even considering the age of other "habitable" stars. We could be one of the first honestly. Or we could just be way too far from any others to ever reasonably detect them.
The activity of any species older than us by a few million years should be easily detectable. There are some underlying assumptions and reasoning as the the following premise's that I can go into but as for the probe reasoning. -Every space fairings species wants to send probes to every star in the galaxy. (Its a matter of survival at minimum not just curious/exploratory species. When probes take minimal resources vs the threat of a species evolving that wants to wipe you out you send probes just to make sure. They have to always be watching since basic smart animal to sapient space faring race takes a very short time.) -Such probes if self-replicating can cover the entire milky way in under 500,000 years and more likely in under 200,000 years. Given that it only takes a 50% light speed sail to do that. -The evidence of such machines filling the galaxy would be difficult to miss. Especially given the constant need for upkeep, maintenance and planetary surveillance. -Even if somehow such activity was hidden from us; it is unlikely that a species would both moraley align with us AND also wish to hold off first contact till a significantly later date than now given the level of moral injustice their technology and guidance could correct. -Any species that is moraley unaligned with us would have simply destroyed or contained us by now as our mere existence poses an existential threat to them given we cannot coexist. Thus no extent sapient species exist within the milky way besides us.
I love all your episodes, and the crossover was really unexpected and fun! I generally think the Fermi Paradox isn't much more than an interesting thought. There's a million potential reasons why we might not have detected any signs and only one of them is "no aliens here". Still a good hook to consider reasons we might be the only advanced lifeforms in our galaxy.
I think it is fair to say that the Fermi Paradox is more than an interesting thought. It presents a real, specific, falsifiable prediction based on the null hypothesis. It's not just the total absence of any technosignature, but one very specific technosignature that would be impossible for us to ignore. As mentioned in at least one other video - to which this one alludes - even assuming that it is impossible for any technology to match, much less exceed the speed of light, it would still take much, much less than a billion years for just one species to colonize the entire galaxy - once they have developed the technology to mass-produce spacecraft capable of achieving relativistic speeds. After 4.5 billion years of our solar system's existence, we're not there yet, but we have no reason to believe that it'll take us 1 billion years to get there. It even seems that we'll have the tech to get started on that millions-of-years-long effort within the next thousand years. Based on the constraints presented by this video, there seem to be about a billion stars that could've produced a technological species such as our own, and *most* of them have plausibly had a "billion-year head start." The null-hypothesis, then, is twofold: first, that stellar systems capable of producing human-like intelligence is common, and that it should only take 4.5 billion years for that intelligence to achieve our current level of technological development. And the seemingly *necessary* consequence of that statement, given the constraints established in the video, is that *our own* stellar system should have been colonized before we even existed. This means that we likely would have never evolved, since they would've filled the same niche in our biosphere that we do. The question posed by the Paradox is "why are we here instead of them." We've tested that prediction and falsified it - we exist, Q.E.D. The less extreme form of this prediction is that they wouldn't have settled every stellar system, but they would have probed them - extensively (and are probably still doing it). If so, then we should expect to find considerable evidence - derelict spaceships on the Moon, Mars, just floating around, etc (not necessarily crashed, but even just abandoned or decommissioned) - or some evidence of past mining activity on Earth, using technology equal or better than our own. But we haven't seen anything of that sort even though we've explored quite a few parts of our system *really* close (especially the parts that would likely be most interesting to them). This was, of course, even more perplexing in Fermi's time than ours, since the known constraint wasn't 1 billion stellar systems - since less was known about the nature of stars - but rather over 100 billion. You're right that there are plenty or resolutions to Fermi's paradox, but all of them fall in the following 4 categories. The first two are that one component of the null hypothesis is wrong: either intelligent life is so unbelievably rare that we are actually the first species of intelligent life to emerge in the entire galaxy (or at least so incredibly rare that *all* such species are extremely close in age - in cosmological terms - to us) or it is unimaginably rare for intelligent life to reach the point we have in *only* 4.5 billion years. The third is that something *necessarily* stops *every* species from accomplishing this task before they reach the tech level to do it. This would mean that something stops intelligent life from doing what we observe most life doing - filling every single nook and cranny that they possibly can - and even what our own intelligent species always seems to do - gathering as much data as practical about its surroundings (and also frequently expanding the scope of "as practical"). The fourth is that more advanced intelligent species are simply *really* good hiding their presence *and* that *all* (or nearly all) of them actually choose to do so - not just every species, but every member of the species that has any way of intentionally or accidentally revealing the existence of the species to us. Of course, not of these, as I have expressed them are mutually exclusive. Invoking all of them, might involve making fewer assumptions. TD;LR: Our available evidence suggests, that, not only *could* intelligent life more technologically advanced than us it actually *MUST* exist - statistically speaking. It also *MUST* have either prevented our own existence (whether accidentally or intentionally) or provided overwhelmingly strong evidence of its existence. This has not happened. Therefore *something* must be wrong with our dataset. This is more than a mere *hook* to the wild idea that we might be alone in the galaxy, rather it is to astrobiology what the "crisis in cosmology" is to astrophysics or similar to the fact the General Relativity and the Standard Model of quantum mechanics both (seemingly) predict too much to be wrong yet also (seem) to contradict each other (leading to the search for a "Theory of Everything" that reconciles the two). It could probably be said that solving Fermi's Paradox is the main objective of the entire field of astrobiology right now. NOTE: This comment ended up being much longer than I thought it'd be, sorry about that. Also, it was probably incorrect for me to speak of just one null hypothesis with two components. It is probably more correct to speak of 2 null hypotheses; I started writing this with the statement of one null hypothesis, and I decided to roll with it because going back and changing it was too much trouble.
@@jeffbenton6183 That was a very long comment. But for me this hypothesis fails on the point that we expect an alien technologically advances species to adhere to a specific way of thinking and acting. Why wouldn't such a species not decide to stay local for as long as possible, only moving as far as they need, a few planets at a time to avoid complete extinction in an unforeseen extinction-level event? Or maybe they don't even mind taking the risk of extinction, preferring to stay local anyway. No species needs to settle galaxy-wide. No species needs to want to make contact with other advanced species. What if they are inherently against colonizing at all? The fermi-paradox just does not take into consideration that a species may not have the same ambitions as 1900s european colonialist.
@@JeiFaeKlubsWell said! In addition, I think that it is clear at this point in human history that being a colonizer is not a sustainable mentality for a society anyways, as it requires society to ignore important values like environmental protection in the pursuit of expansion and capitalization. If we want to apply this mentality to aliens then we also have to grapple with the fact that the desire to colonize the galaxy very well could be the critical factor that makes it an impossibility for an alien society to do so as it requires them to value expansion and capitalization over sustainability of their own society. Because most of us have lived our whole lives in capitalist dominated countries, it's hard for us to truly realize the profound unsustainability of colonizer-capitalist society.
@@jeffbenton6183 I love long comments and yours was interesting to read, but I can't help but point out how Fermi paradox is total nonsense. What's missing in that model is that we still have no clue how something dead becomes alive, which is basically the most important thing, and proper scientific thinking would be that we can't even speculate about existence of life elsewhere until we figure that out. For example, it could be that certain mix of matter needs to be at specific temperature, exposed to specific dose of radiation, and those conditions need to be true for specific amount of time for life to even have a chance to emerge. Or perhaps life emerges as soon as there is liquid water on the planet for long enough time. You can see how some of these being true would totally change the equation about the possibility of other life in the universe. Of course, we know that the second isn't true, as we are yet to observe life emerging from something non-living. So for objective thinkers there is no such paradox.
@@julius43461 That one has been found, at least for earthlike life. Deep-sea hydrothermal vents produce a continual geologic outpour of organic chemicals. The hot vent in the cold sea means there's a temperature gradient, and as these chemicals cool, they naturally link up into longer and longer chains. We see these form amino acids and then peptides already - the only thing keeping us from seeing the rest of the process in action is life itself. There are families of extremophiles whose main evolutionary pressure seems to be getting closer than each other to these sources, so they can eat the outpour before anyone else does. However, we do see uneaten peptides escape, and it's easy to see from there how this is a rapid dictionary attack on the building blocks of life. If something sterilized the planet of all life, even killing those extremophiles, then there would be random enzymes catalyzing away within an hour. It turns out the RNA world is continuously generated in many places over the planet by geologic processes. There is a vulnerable point in Drake's equation, but it's at the other end - once technological civilization arises, how likely are we to recognize it? Given we wouldn't be able to detect an identical civilization around Proxima Centauri, and technology branches wildly and builds on itself, it's pretty darn unlikely.
One possible answer to the fermi paradox is that most (if not all) of technological civilizations cause their own demise. It could be that the nature of competition in all life is a deterrent in becoming an interstellar species.
I think that the most issue is time, the radius of interaction from earth since we started sending radio signals is really small compared with the whole size of the galaxy
and if any life did get the singles, they would have to figure out what it is saying and find where it came from to send a response. that is if they can even get the single.
This is always what I think too. I think even scientists seem to somehow underestimate the huge distances and the vastness of space. Even if our galaxy contained life which is on the same technological level as ours, we wouldnt be able to detect it. Our own "radio bubble" just barely stretches out what, like 100 light years? And the signal is probably so weak by that distance that it is basically impossible to detect. We just started detecting the first exoplanets the last couple of decades.. and they are all very close to us in galactic dimensions. Space is just too big and everything is too far apart for us to ever detect alien life. This applies to our galaxy. Other galaxies are even more unlikely to be accessed by any of our sensors, and we certainly will never be able to travel there.
@@CanariasCanariass If there was a technologically advanced race contemporaneous with us, that would mean they're incredibly common, and we should be seeing evidence of the billions of civilizations that evolved over the last few billion years. There's no reason complex life couldn't have evolved as quickly as a couple billion years after the big bang.
@@jeffhoward162 How so? We wouldnt even be able to detect a signal from them if they were like 100 light years away, given their signals are of the same strength as ours. We can only scan such a tiny amount of space for life it seems ridicolous.
Recall all the systems with "Hot Jupiter's"; these system might have formed small rocky planets with oceans but the giant came in and ejected them. One needs a Saturn to go along with the Jupiter. Then the two together help clear dangerous debris but also do not enter the inner habitual zone destroying those vital planets (by stopping their growth or ejecting them.) Then any small planets in the habitual zone can't be too small or its core will cool too fast and no protective magnetic field will exist long enough to protect the atmosphere from solar wind and being striped away. Then a large enough Moon to prevent extreme changes in the planets spin axis/orientation (leads to wild swings in all regions for temperature and light duration.) Just these (and we know more) are absolute minimums for a planet to have in order for large complex life to have time to evolve. That likely takes the 40 billion or so down to well under a few tens of thousands. And the list goes on - as such, wouldn't be too surprised if it turns out there are only a handful of solar systems in our galaxy that are true "Goldilocks" like our system so advance beings could evolve.
I don't think we have not ruled out Super Nova as the great filter. With the discovery of Hyper Nova, we now know that some Nova explosions are so powerful they destroy all life in 25% of a Galaxy like our own. These rare but powerful explosions have finally settled down in our Galaxy to the point where life can exist. It's very possible we are the first.
Maybe intelligent life only exists for such a short time that it would be extraordinarily rare for 2 intelligent life's to exist at the same time AND close enough to notice each other
This is the most intelligent explanation I have ever heard! How come no scientist has said this already? It is almost as obvious as Darwin's theory of evolution to which T.H.Huxley replied: "How stupid not to have thought of that!". The simplest explanations, Occam's Razor, lifts its head again....
I think the other two major factors about our solar system that allowed complex life to develop are: our Moon and the position of Jupiter. It seems likely that something happened in the early solar system that distributed things in a way that was uncommon, even among similar star systems
Regardless of how strict requirements are for life to exist, it could be literally one in a pentillion [edit: quintillion] and it still wouldn’t be any surprise that we’re in it. We obviously have to be in a place where the universe is conducive to intelligent life because we exist. I think this is called the Anthropic Principle?
@@crsmith6226 it definitely couldn't be one in a Pentillion (cause that's not a real thing), the Milky way is estimated to have 8 billion earth like planets, and the universe is estimated to have around 100-200 Billion galaxy's, back of the napkin using 200 billion thats eight hundred quintillion (8×10²⁰)
@@crsmith6226 I mean, I think there was a paper in 2001 that proposed a consistent way to name large numbers that used Pentillion instead of Quintillion, but it was never adopted anywhere because everyone already used The Conway-Guy system of scientific notation.
The series "Zones of Thought" is based around the idea that the core area prevents intelligent life. The region we live in is the "slow zone" is the first where intelligence can develop but further out is "the beyond" where advanced intelligence can develop and in the galactic halo is "The transcend" where things so advanced they might as well be gods live.
Indeed. Imagine what humans will think of our civilization a thousand years from now, if we continue at our current exponential technological pace or greater. Assuming, of course, we survive that long. Now imagine what another intelligent entity a million years ahead of us would think of us. As Sagan so eloquently stated, "they wouldn't". They could no doubt manipulate things in such a way to say, make Venus look as it does. All while hiding in plain site. And living hidden in a physical state we can't even conceive of.
Could it not be that the odds of life starting in the first place even in identical conditions are so vanishingly smaller. As I understand we still think it only happened once on our planet , so what if we just got unbelievably lucky.
That may indeed be the case, or any of an unknowable number of other 'great and small filters'. Our 'estimates' on the abundance of life, or not, have a data point of one. So we are caught anywhere between the mediocrity principle and the Earth being genuinely the only place life exists, there is just no way of knowing and we may never know. FWLIW: I tend to take the view there is nobody out there because for all practicable purposes there may as well not be unless we find evidence to the contrary.
Crazy to think that the entire fictional Star Wars “universe” takes place in just 1 galaxy. And there are trillions of galaxies in our universe. Then imagine a multiverse existence and it just blows my mind
Only one species in the history of the Earth has even realized that outer space exists, much less being able to travel through it. Our level of intelligence may be rare.
This isn't necessarily true, there are multiple different animals that use stars to navigate. I suppose it depends on exactly what you mean by realizing outer space exists though.
Yea i think so too it took a long time for humans to exist other animals have done nothing advanced and for most of the existence of our species we where just tribal hunters then we where non industrial civilizations for 1000s of years only in the last 200 years have we really been thinking about aliens in a realistic way.
The sun being one of the younger stars, with most others being at least a billion years older a frightening thought comes to mind. Perhaps other civilizations did exist, far more advanced than our own, and have already died off and returned to dust. Perhaps the great filter is still ahead of us.
As nice as the co host was, space time wouldn't be the same without Matt. Watching somebody else present the latest episode made me realize how little I was interested in watching when presented by someone else. Matt makes space time so enjoyable, it won't be the same when you leave.
Thing is that fermi paradox was ACTUALLY solved on 24 february 2022. All emerging civilazations cant agree within themselves and just die in big nuclear wars.
My suggestion for an answer to the Fermi Paradox is this: Human beings are obsessed with materialistic things and especially technological progress, thinking all this is the cause of happiness when in fact it's not. We're so obsessed with technology as 'the answer' and so egocentric that we can barely even imagine a highly intelligent species which is not highly materialistic, highly technological, and overpopulating its planet. The truth might be that WE as a species are not as mature, as intelligent or advanced as we like to think. There could be many advanced, intelligent species out there who are contented and peaceful, living in harmony and enjoying the real cause of happiness - inner peace - who have no great need for technology and materialistic life and so aren't easily detected by our tech-obsessed search. Hopefully, maybe, one day human beings will head in that direction too!
unfortunately, inner peace doesn't solve disease, or house people, or increase the food supply. all those things are done with technology. humans are an extremely primitive backwoods not worthy of intergalactic travel civilization, but that doesn't mean that the answer to life is inner peace, that's the subjective opinion. a lot of what you say here sounds reasonable and seems like it makes sense, but when you think about it a lot of it really doesn't. you should watch some star trek. one thing though, is that if you set your sights a lot shorter, like here on Earth for instance, dolphins and whales and pigs are like all extremely intelligent, possibly even more so than humans. but humans like to compare everything to humans, it's like calling a turtle slow because it can't beat a cheetah or something or it's like giving a dog and IQ test, it's when you compare things on a human centric standard you miss a lot of stuff. so that part of what you said was cool
@@clown134 thanks for your reply but you've really gone a long way off what I said. I never said there's anything wrong with technology or that it couldn't co-exist with inner peace. What I said was the obsession with technology (which is the opposite of a peaceful mind) is causing some problems. You said inner peace isn't the answer to life, I didn't say that, I said it was the cause of happiness. You can still have medicine, tools, houses when you are at peace - why not? On the other hand if you're saying all we need is technology and not peaceful positive minds AS WELL, then why are there so many new dangers in the world caused by technology, and why do human beings have so much unhappiness and misery still? Right now the Russians are using superior technology to cause untold misery and destruction in Ukraine. This is caused by greed, arrogance, hatred - unpeaceful minds. So the cause of world peace would not be technology but compassion, loving-kindness, contentment etc: peaceful minds. Humans are nowhere near achieving that yet, but maybe some intelligent civilisations elsewhere have achieved it. That's all I said really. Sending good wishes to you.
I love reading the comments after watching the video. Alot of my questions answered there. But I have yet to see any theory that addresses the habitable zones for binary star systems. Certainly binary systems have planets. 2 stars would mean more metal. Aren't binary stars more stable? More light means life could begin farther away from the stars than the Earth is from the Sun.
That's it! I can't take it anymore. I'm starting an 80s heavy-metal band called MetaliCity, and I'm going to use everything I've learned on this channel to make it an _actual_ 80s band by going back in time.
I don't know what is more terrifying: the idea that aliens could have a billion-year lead on our development or the possibility that Earth might be the first planet to host technological life.
I think it would be even more terrifying if aliens did have billion-year leads on development but we still lapped them technologically in 100 years. At that point, both species need to stop whatever they're doing and start asking themselves some serious questions why that happened. Starting with the very real possibility we're in a simulated universe, and that one or both of us may also be simulations.
Also, I think it'd also be terrifying to know that aliens did have a billion-year lead on development but technology stops really progressing at about, say, 80 years from now. Meaning that their head start doesn't amount to anything. That is, there's a real chance that someone alive today will see the last thing ever invented by humans.
I'll pose a question. Imagine that there was only one person on each continent on earth. Now, they are immortal but still subject to the laws of physics and other plants and animals still exists. How long do you think it'd take for 2 people to run into each other?
I'm reminded of a series of short stories by Larry Niven, where aliens contacted us who were galactic conquerors, but all they were interested in were red dwarf star systems as that's the environment they evolved in. Having the ability to keep their existence secret from us, they only came calling because they wanted to use the solar system as a kind of railway station/stopover, with no interest in conquering it.
Every "just so" story like this neglects the fact that there should be thousands of alien civilisations out there and only one needs to make contact. It is far more likely that technology inevitably and tragically destroys civilisations and planets just as they begin to explore the galaxy.
@@jimcrelm9478 Naw. My opinion is that the conditions for advanced life to develop on a planet and then develop into intelligence is a very very rare occurrence. So rare that some galaxies may not have intelligent life at all.
@@montylc2001 18Scopii and HIP 56948 are two stars nearly identical to the Sol system in almost every way possible to the point of being almost too good to be true. 18Scorpii is 45 light years away and HIP 56948 is 208 light years away. Scorpii is 1 billion years younger, meaning its still in the primordial ooze stage of life. (if it has life at all). meanwhile HIP, if it has life, is 2 billions years older than us. It seems highly unlikely that HIP won't have complex life. It is unthinkable that in 2 billion years it didn't develop intelligent life at some point. Maybe it did and its long gone by now. (assuming the conditions are perfect for life there). But if they had life, how could a planet so close to us, not have visited us by now? It begs a lot of questions. Maybe there was intelligent life. Maybe a pandemic wiped them out. Or they wiped themselves out. It is just so damn easy to do. Would we even find any evidence of their existence after 2 billion years? So So many questions.
@@FablestoneSeries Earth is rare. Advanced life may be very rare as such is on this planet because of the Moons influence, and the exact conditions of how the moon formed are going to be very very rare. Plus many other factors. Recent research indicates that if Earth did not have the Moon, and the after effects of the moon's formation directly on the Earth not counting tidal effects, advanced life probably would not have developed at all.
A Spacetime episode that I didn't have to rewatch multiple times to get a fingerhold on the physics. I don't know if I should be excited or disappointed.
Shout out to the Zones of Thought concept as thought up by Vernor Vinge. The book A Fire Upon the Deep is amazing and talks more about why we might not be able to see other civilizations because of our location in the galaxy.
What if there is a 'habitable zone' for spatial dimensions? Imagine infinite dimensions from string theory on up. We find ourselves in a nice spot in the middle.
One concept related to dark matter is of interest here. We could be living in a minority type region of the universe, the "electromagnetic reactive zones". Dark Mater is simply called that as it doesn't appear to react, interact, or produce most (or all) known forms of electromagnetic radiation. Light just moves around it or passes through it without either interacting *think photons are like neutrinos to dark matter*, but Dark Matter does have mass, so that causes problems right there for unified field theories when something interacts with one aspect of space time but ignores another "fundamental force". So what if Dark Matter is not one element, but has variations, elements, soils, stones, compounds, and even living structures. There could be entire regions of space following some of those other dimensions theorized in String Theory that they interact with but we don't, entire regions of space effectively invisible to us and us invisible to them more than likely, but both partially aware the other exists due to detecting the influences of gravity.
@@TheRhuen those other dimensions in string theory are compact dimensions, not full spatial dimensions. Only something on the scale of an elementary particle could interact with them.
what do you mean by infinite dimension, its hard to just understand the like 10 or 11 but infinite!! does that even have meaning ? i heard if there is more or less this universe will get unstable like the laws of physics will not be the same but what do i know i m not a physician i just don't like this kind of infinity it hurts my head
"The Fermi Paradox" is a misnomer. It is not a "paradox", it's a problem. There's nothing paradoxical about it. It should be called "The Fermi Problem".
It's a paradox in the sense the observations doesn't match at all the theory. Fermi life's equation tell us there should be millions of alien civilizations...and yet we've seen ZERO
The unfathomable scale of creation makes me think the Fermi Paradox grants statistically consistent authority to any and all factors of the universe to work against us. I believe it to be a combination of everything from technological barriers, chronological barriers, stellar activity or lack thereof, galactic activity or lack thereof, sustainability crises, any and all potential factors will have room to work however they may in a universe large enough for anything to happen.
What I wonder about is tectonic plates, and how much they have to do with life becoming as varied enough to develop into an intelligence high enough to want to explore away from their homeworld.
Seems like the answer to the fermi paradox is that life is very rare, intelligent life is exceptionally rare, technological life is EXCEDINGLY rare, and space faring technological life is all but impossible...especially given time and speed of light constraints. The hurdles are exponentially compounding interest, and Einstein called that the most powerful process in existence. The laws of the universe may make true galactic travel impractical. We have a gem of a planet. No point in looking any further unless we can learn to sustain this planet first.
That's a guess that supports how you feel, not "the answer." To find out if it indeed is the answer, we have to continue looking outside our planet. Solid evidence is how we get to "is" instead of where you/we are now, which is actually "might."
Seeing this video right now, maybe you can do a video about stars in general one day. A few questions I have about them: - Is a star basically a planet that was big enough to ignite fusion? - How do binary or tertiary star systems form compared to regular ones?
Another issue is that our Sun likely formed in a pair, and that’s why Earth is where it is, and Jupiter is not the closest body. The second star dragged our solar system into disarray and moved the rocky planets to the inside and the gas planets to the outside. Most solar systems have the same arrangement as would be expected, with the largest and lightest closest to their star.
@@colonelsanderson That would also be pretty cool, but you would still need the incredibly unlikely circumstances of shuffling that happens with the earth
I'm not an evolutionary biologist but I would guess that, with what we know about evolution, it's a process that would favour simple lifeforms. Complex creatures capable of thinking and building structures are not as good at propagating as other simpler lifeforms like fungi or bacteria. That still doesn't solve the paradox, but it's possible that life in Earth is a very rare and fleeting thing, right? Maybe it happens only a few hundreds of thousands of times in every galaxy.
Actually being large and multicellular offers many advantages over simple life, which is precisely why it evolved and flourished. The step from single to multicellular doesn't seem that difficult today as many transitional organisms are observed such as slime molds.
@@filonin2 Again I understand I could be completely wrong about this but wasn't there a significant period of time where the only life on the planet was unicelular? Maybe I need to check again but I remember reading that throughout about half of the history of life on earth, there was only unicelular life.
@@filonin2 Based on the amount of time life has existed and the amount of time it been multicellular it think you have underestimated how difficult the transition was. Also it not possible to have a guess of its difficulty from theory because there is no theory that explains the transition.
there is no paradox. we don't know much about the rest of the universe at what is on other planets. we lack the data to claim anything. It's only a paradox for those who are deluded by too much science fiction.
If you're going to talk about filters, what about one talking about liquid being needed to create life. Point being how many intelligent life forms could simply be lacking technology because they live in liquid. Pretty tough to advance technologically in such environments
Only because humans did not evolve in water. What seems difficult to us could be an obvious solution to a species that has been evolving methods for building and living underwater for thousands of years.
The arctic still has liquid water which we have good reason to expect is required. The habitable zone is pretty generously wide (and it's a fuzzy band) to allow for all sorts of variations.
The simple answer: While general life may last for billions of years, I suspect that civilizations have limited viability. They are their own greatest threat. While science can solve technical problems, "advanced" life is short-sighted and morally stupid.
I think you're just referring to humans. To assume that any and all intelligent or advanced life would behave like us is...well, short sighted and stupid. 😆
@@the300club8 Consider the fact that all advanced life has to evolve from single cell organisms... then it seems short sighted and stupid to think that there is the slightest chance for any intelligent life anywhere to evolve from something other than wild active animals, and therefore it's actually wise to assume that practically all intelligent life will have to go through the same technological, sociological, political problems as our does, and considering how easy it is to destroy our environment not only with nuclear weapons its also quite wise to assume that this might be the great filter - being that intelligent civilizations most of the time destroy themselves before they're capable of evolving enough to strike a balance with their environment, leave behind petty interplanetary quarrels in the name of unity and greater things. We're still a long way from that, but I'd say that the fact that we already didn't blow the planet up along with all complex life on it is a really good prognostic.
Idk man, Chogoris is right in that zone. It may not be the most hospitable planet but Jagati faired well there and the Whitescars like it as the home to their Fortress Monastery
I want to mention ideas like "Wang's Carpets" by the author Greg Egan. It is highly possible that any life we discover is entirely unlike any idea of what we have for life on our planet. There are a *lot* of presumptions we make about the nature of life in these discussions.
I wouldn't say its larger than 90% of stars, after all we see stars that could have just become giant but to space time and and stuff it only appears small.
I just want to say the discussions in the comments of this video are not only rewarding and educating to read but people are respecting each other. Not even sure i am on CZcams.
Be sure to check out Matt discussing nuclear fusion on "How Sun Mythologies Are Universal" over on Fate & Fabled and tell them (politely) that Space Time sent you! czcams.com/video/utJZ8YmXOnc/video.html
What about captured planets or material on the galactic edge
I'm thinking that any alien that tried to reach us would cause a Planet of the Apes / Interstellar scenario where by the time they got here it would be much later into the future for us, relatively speaking.
Check out a scientific paper titled "Migrating extraterrestrial civilizations and interstellar colonization: implications for SETI and SETA" published by International Journal of Astrobiology, Cambridge University Press. It discusses how extraterrestrial civilizations may travel from their home worlds to the Solar System and other planetary systems.
Why does higher metallicity create more giant planets.
FYI: A phrase is not a question just because you marked it as such. Please review your title, it is not a question.
Does this phrase sufficiently exemplify the inverse of my point. Great?
From the SETI website:
"If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth?
In general, no."
This is a point. Broadcast signals degenerate over interstellar distances. As I understand it, after about 40 or 50 lightyears, the signal would degenerate so much to be hardly perceptible at all; it'd be drowned out by background noise. Now, a strong enough signal, or a highly focused signal might make it, but you'd have to know exactly where to send the signal, and assume the intended recipient would know exactly where to look to find it.
So, why are we doing the SETI project if we don’t think that it is the right approach?
@@cytrax We're looking for more advanced or louder life - hopefully in the next few thousand years we'll be registering on alien SETIs
We've only been broadcasting ourselves into space for a relatively short time anyhow. In addition to the generally low power level of those broadcasts.
There's why there's a "great silence". That IF other civilizations also use radio.
One bias not mentioned is our assumption of habitable planets. What about habitable moons?! Wouldn’t a high metalocity system include an abundance of moons? Would they be susceptible to the same problems or protected by their host planet?
That's a very good point. Say that a G0 star (which is just a tad massive and brighter than the sun ) have a high metalicity, and therefore is populated by a brown dwarf companion (Sol is a outlier for being alone, actually, and that might be another factor for life, who knows) and has five gas giants, and at least 3 of them have the conditions for life in their moons (Say that one moon is earth-like, one is like Europa and other is like Titan)
Moons are smaller and thefor will have a much smaller magnetic field and it would last for much less time. Also the lack of atmospheric pressure would make water difficult to stay liquid.
@@eligoldman9200 Ganymede is 41% the size of earth and is more protected by Jupiter's magnetic field than Earth is protected by it's own. Venus is only 5/6th the mass of Earth, yet it's atmospheric pressure is 95 times higher than on earth.
So between those three facts it is entirely possible that a system with many gas giants could have a moon that could support life.
Are there NO moons out there that aren't roughly earth sized? Surely with the scale of some gas giants, they would pull in more moon and satellite material.
So explain to me with your science how the ewoks survived? /s lol
There are so many variables to this aspect that it's mind boggling. There could have been intelligent life a million years older than that on Earth that was wiped out by a meteor. Or life just starting on a planet because it recently (in a glactic sense) moved into a habitable zone. Etc. We could be the first intelligent life in our area. We just don't know.
However, I've said this before, and I'll say it again - the moment we landed on the moon, aliens became real. :)
This kurzgesagt video might help czcams.com/video/KRvv0QdruMQ/video.html
We do have enough of an idea of Earth's past so assert with confidence that there's never been a humanoid species that ever became as technologically advanced as us. Such technology would've survived in at least some form for eventual discovery, considering biological decay is so slow, sometimes not at all. Also there's no evidence of an extinction-event meteor after the dinosaurs-extinction one, since the primary way we know about that is a layer or iridium that's rare on Earth but common and asteroids in the fossil record, plus a great difference in fossils before and after, that doesn't show in the fossil record in anywhere near the same degree since.
@@PoochieCollins You are correct in saying we are the most technologically advanced...on Earth. However, we aren't talking about life just on Earth though. We're talking about life in the solar system, galaxy and/or the universe.
@@meacadwell oh okay, I interpreted your OP to suggest that advanced civilizations might've lived on Earth before.
I agree. They’re could’ve been civilizations like 3 billion years ago, and thousands since. There could be tons right now, way behind us or way ahead of us. And there could be millions more in the coming billions of years. We have no idea. Even if there was just ONE civilization per galaxy then there would be 2 trillion civilizations. MIND BOGGLING
Wait a minute, hold on. I only signed up for an astronomy video.
If not for the late, heavy bombardment, we may not have had enough metals and other elements that are essential for technology as we know it. I wonder, of all the other earthlike planets, how many actually have a high enough abundance of the proper raw materials within the grasp of the planet's intelligent inhabitants.
Good question, but again it's just an unimaginable scale of numbers.
Out of the billions of possible planets, are the odds truly so low that only a handful would have had enough? And that then those handfuls that came before us haven't made their presence known in the hundreds of millions of years they might've had?
It's entirely possible we're just extremely lucky. it makes me think of the antrhopic principle. That said, the numbers are just too vast imo. The rare earth hypothesis just seems so uncompelling to me.
What about things like gravity? What if a planet has such a dense atmosphere nothing living on the ground has ever seen a star or even their own Sun? So they never even think to explore outside of what they know? What if they can see the stars but gravity is so heavy, it is impossible to reach orbit? There's a lot to be said about living in 1G with a relatively clear atmosphere.
Analogs of the late, heavy bombardment probably existed in most planetary systems.
There are a number of things that need to happen in order for "us" to arrive...
From Theia slamming into the primordial planet and creating our Moon while increasing our planets core by almost half again.
The larger core gave us a very strong dynamo to withstand the sun's wind and block radiation.
This same Moon slowing the spin down with gravity while causing the tidal pools that will harbor the first life .
Mars wasn't so lucky and when its core solidified, the solar wind blew its atmosphere into space.
The Late Heavy Bombardment restocked the Earth's upper crust with literally billions of tons of metals.
Almost all of the original metals were subducted into the core while the planet was molten.
Canada had to have been smacked really good with a huge Nickel-Iron meteor which gave it the vast mineral resources it has today.
@@liberalrationalist8905 Agreed, but it's the composition of the incoming meteors that determine what you get as far as metals. The metallicity of the original star cloud determines that.
Life is so incredibly fragile, that it's surprising that we exist at all.
*LIFE is NOT fragile ! It is Non-Dimensional ! Know Thy SELF !*
@@johnb8854 Cringe
@@brauljo he's right. Consciousness is quantum
@@ok0_0 how is that proven? Genuinely curious!
@@exerciseforidiots2296 I don't think it is, but hey we(I?) can't prove that anyone else is even conscious, but we still believe that to be true.
"Most of us have never seen aliens"
Always good to start a science video with a laugh. 😂
About the Fermi paradox, I think it's only a paradox if you're searching for solar conditions that will allow for life but if you're thinking about intelligent life and galactic civilization then you have to account for planetary and evolutionary conditions. My understanding is that from an evolutionary perspective the emergence of intelligence is a path dependent process. Which means that a finite number of paths that lead to intelligence will be practically zero percent of the space of possibilities of the evolution paths. Great video as always, btw!
I don't know man. There will always be trees (presuming terrestrial life and photosynthesis). There will always be monkeys inhabiting those trees, with great spatio-temporal intelligence. And they could always leave the trees freeing up their hands. And they are usually social. This, I'd hypothesize, is a fairly typical path to intelligence. I don't see this as a niche that remains empty for long unless you had say dinos keeping mammals small.
My guess is that the great filter probably lies in front of us with various kinds of existential civilizational risks.
@@sharif1306 That's a very big supposition. Complex life on land existed for hundreds of millions of years without complex intelligence evolving. There were no intelligent, tool-using Dinosaurs. Without the mass extinction at the K-T boundary, mammals would not have been able to expand into the open niches and take over the planet.
In fact, there is a lot of evidence that long-term "locking" of niches occurs, where things settle into local maximums that are semi-optimal but nothing else can evolve because the niches are full, even if other body plans would be better. Mass-extinctions may be necessary to "shake up" evolution. It's essentially re-rolling the dice on all the ecosystems and getting a new local maximum. This happened quite a few times before humans evolved by chance to be intelligent enough to create a paradigm shift. On planets that are too stable, this might not occur enough and they just languish with poor local maximums and niches filled with low-intelligence animals. But if you have too much destruction, then the mass extinctions might also preclude complex intelligence.
There are lots of examples that indicate that Earth is "fine tuned" for intelligent life to develop here, and that its past was "lucky". This is all the result of the Anthropic Principle though. Of course Earth is fine tuned for intelligent life to develop here; if it wasn't then intelligent life would not be here to observe it.
@@insertphrasehere15 I believe the anthropic principle speaks to the physical laws of our universe rather than any particular place in it.
But I see your point. I was just alluding to the conduciveness of the tree dwelling niche to the development of spatial and general intelligence abilities. Even our brain is mostly just a scaled up primate brain according to recent work.
In any case, as Jesus said, "The meek shall inherit the earth" - thanks to that fortuitous cataclysm bearing down on earth 65 millions ago having been disturbed from its abode in the OORT cloud further back in time.
I still maintain that we've ALL met aliens. And they are known as .... Virus'
The standing assumption in science appears to be none of us have seen aliens, despite testimonials, video or radar evidence. But what if that assumption is wrong? What if some of us _have_ seen aliens and just can't convince the rest of us because of social norms? Shouldn't we actually investigate UAPs before trivially rejecting them? There is a lot more which could be done in this area.
i like to believe that life is still pretty common in a relative sense in the galaxy, but one thing that needs to be considered is the window where life is alive. humans have only been around for a short period of time on a universal scale, and that means that maybe detectable life was around before we were here or maybe after we are gone.
Why do you 'like' to believe that? Wouldn't that mean intelligent advanced life rapidly dies out before colonizing the galaxy? I would find our chances much better if intelligent life was some kind of incredibly unlikely occurrence.
Even if we zoomed in with telescope at a distant planet and found cities, we should still assume they are now extinct.
It has also been proposed that one of the greatest limiting factors to the formation of life is the presence of Phosphorus. Phosphorus is created from supernovae. Thus we need a sufficient enough number of supernovae events to have occurred to allow a chance for life to begin. We also need to have that Phosphorus become concentrated enough in certain regions of the Galaxy to allow for Phosphorus-enriched star systems to form.
czcams.com/video/oPU9jeQbTOU/video.html
So far, we've only really been able to make educated guesses about alien life of any kind up till now. So many pros and cons to consider. Most people end up tying themselves in knots trying to fathom some answers. Hopefully JWST will help shed some light on this subject over the next few years.
I'd say that the "educated" part of their guesswork is minimal. It is just pure speculation.
@@chuckschillingvideos I think people really overestimate the amount of systems we could've realistically looked at by now, it's very confusing to me how someone could genuinely believe the fermi paradox is a paradox when there's 100 billion galaxies and within our lifetimes there's no chance we can even actually analyze .0001% of a single galaxy.
It almost seems comically idiotic to assume we'd have found aliens easily yet that's what everyone assumes for some reason. If we're being entirely honest we're not even really capable of searching yet.
@@erdelegy Those are guesses, that do nothing to remove guesswork.
Fleshy fingers to manipulate tools? Is that serious? I can think of a half dozen different and very capable methods of manipulation, and I am hardly an authority.
@@chuckschillingvideos Look at the Cool Worlds channel I'd say there's substantial statistics and math involved in this educated guess. The problem is of course we only have a single sample.
@@chuckschillingvideos I think you're being very unfair. Scientists have predicted all sorts correctly. From gravitational waves to hydrocarbons flowing like water on Titan. But there's always that surprise that nobody saw coming.
Now we have JWST just around the corner from science work. No speculation went into that at all. It's been perfect throughout.
The moon being so large (tidal energy extends the life of our metal core) and mix of land and water are probably rare being in the habitable zone of our star type. We also are almost as large as we could be and still get off the planet via rockets, giving us the gravity to maintain an atmosphere while still being able to escape.
i think you can escape a planet with a couple of multiples of earths gravity, you just need to develop a more energy dense fuel than we needed to first. might take a good while tho.
The moon to earth ratio is most coincidental and rare.
Coincidental? Sure.
Rare? *Absolutely not!*
There is also the fact that the Earth is not just any rocky planet. Earth has an unusually large, metal-rich core which generates a robust magnetosphere which protects the atmosphere. Mars doesn’t have a robust magnetosphere, and so lost a bunch of it’s atmosphere over time. Even Venus is slowly bleeding armosphere, it just that it is so thick that it remains cloaked even after a planet like Mars has lost the ability to retain liquid water.
@@jonhall2274 What are you basing your "absolutly not!" on?
I still feel like the most reasonable resolution to the Fermi paradox is "no civilization ever develops to the point where we could detect them with our current 'primitive' methods". Which I guess includes no civilization ever making Von Neumann probes for one reason or another.
Someone pointed out a interesting fact. We as a species are becoming silent. Before we would podcast signals through radio waves all across the planet but now most of our communication are in hardlines buried under the ground. Even something as basic as music and news are now mostly streaming online or being downloaded as a podcast in MP3 format. Couple more decades and we may not be broadcasting anything. That happened within only a 50-year time span. Now we are talking about communicating with lasers.
@@bryanshoemaker6120 Good point. Efficiency is served that way too. Radiation is, after all, loss.
I wonder. We think in terms of unlimited expansion and expanding resource consumption. Maybe this mindset is a phase of early development. Then civilizations find it not worth the bother or something. Island cultures have learned to cultivate resources, the hard way, several times. Existence in a steady state can be achieved and flourish, taking the long view and allowing for generations ahead. Like homeostasis as opposed to cancer. And the grown-up aliens are just hangin, enjoying existence. Quiet and balanced is good.
@@MrJimbissle That! And maybe through vast amount of time individuals of that civilization can acquire unimaginable senses thorough which they can percieve universe non locally.
@@MrJimbissle The problem with that idea is that it only takes ONE to break that rule to colonize everything and we should've seen it by now.
The more I think about it, the more I wonder if maybe the solution to the Fermi paradox is just that we really happen to be one of the first intelligent species to evolve. It sounded ridiculous to me at first but there are just so many parameters that had to go right. Mostly on the front of biological evolution though. It took so long just to get eukaryotic cells
I don’t think so. Intelligence can develop a lot of other ways and can not resemble humanity’s style. If you like sci-fi and reading - check Peter Watts and his novel Blindsight. That’s a good book and interesting view about alien lifeforms
If you throw dices of 20 faces what are the chances of getting 2 twenties in a row? one in 400. And 3 in a row? one in 8000. And 7 in a row? one in 1.28 billion. And 10 in a row? One in 10 trillion.
Meaning, if there's only 10 conditions that must be met and those have an independent chance of happening of 5% (like only 5% of the stars are the proper size, only 5% of the planets can hold life, only 5% of the galaxy is habitable, only 5% of the planets are old enough for life to develop, etc, etc, etc), you already need on average 10 milky ways to have one single planet hosting life.
The magic of multiplication and exponential functions.
I don’t think it’s a matter of intelligence. Dolphins are maybe as smart as we are, but living in water they’re never going to develop technology. We might end up finding a bunch of intelligent dolphin like aliens who were never able to develop technology because of their environment and biological limitations.
@@kokofan50 that too yea
Simple solution is there are billions of earth like planets but they are so far away that we have no contact. Even at the speed of light it would take hundreds or thousands of years. And you would need an insane number of probes to cover all that space. But also we have solid evidence of alien encounters, alien technology, ufos etc which are just ignored by mainstream science
Whew!! Here within the minute. Right on time for my nap lol
Same, hehe
Yap. 😂
How do you nap and watch at the same time?
@@ulob quantum something
@@ulob superposition of states
My like pushed it from 16k to 17k. The simple things in life. Thanks PBS and Matt for the awesome educating content
Sooo ... your "like" added 999 extra to the count huh - not 1 ?
Wouldn't more heavy elements, thus producing more gas giants around stars, also mean increased chances of exomoons in the habitable zone? The bounds of the galactic habitable zone are there, but perhaps they're fuzzy, with gradients of other possibilities.
I think moons around gas giants are more difficult to detect. You'd have to essentially do the exoplanet detection thing squared. Maybe the lack of detectable information is biasing the extrapolations. Until there is data on the existence of gas giant exo-planet moons (though by any reasonable thought there should be many) they are not considered as part of the running theory. Similar to how it was "shocking" when exo-planets were confirmed and in such large quantities, even though any casual thinking on it should have made their existence not a surprise.
The moons of gas giants tend to be relative cool (which also slows down every chemical reaction), and there is also a lot of radiation. Not the best conditions for the development of complex or even intelligent live.
That is an important question. Some scientists believe there are as many habitable exomoons orbiting gas giants as habitable exoplanets in our galaxy. If there are more gas giants in the center, the higher number of habitable exomoons may offset the lack of habitable exoplanets.
@@wolfgangkranek376 These are examples specific to our solar system, where the gas giants are well beyond the habitable zone. Imagine Jupiter in Mars' orbit! There are known gas-giant exoplanets in similar orbits.
@@ckl9390 You're quite right, scientists have to deal in hard data and models that successfully predict the observed results. We've all of maybe two exomoon candidates detected, though the field is fascination as a visit to the Cool Worlds channel here on CZcams will show.
It's just both surprising and somewhat amazing to me to see Matt getting older in every new episode. Can't believe it's been more than 5 years with him, and the change is astonishing. He's only getting much more genius than he ever was every day.
Glad I wasn't the only one who thought that. I was actually a little concerned since I typically only listen while I'm driving and don't usually see him that clearly.
I think the quality got better, and the lighting is different. And he just lost some weight.
Yeah he looks tired or something here.
.. just imagine if he was getting, y'know, younger..
“A fire upon the deep” by Vernon Vinge explores an intriguing twist on galactic physics - where the laws of physics are subtly different the closer or farther to the Milky Way core you go. As a result different technologies are needed at different levels, and even biological cognition is affected.
Couldn't find a Vernon Vinge anywhere, is he famous? ;)
@@reesetorwad8346 Science-Fans, please know:
One of the most Empathic Videos i ever saw just came out: "Why do I Care?' by 'Belief It Or Not'. Together with the GOP-Videos of 'Some More News', its quite amazing and best coverage of the Attack on Woman-Rights and other things, i know.
For those who wanna be updated and those that have Empathy (a combinttion that will make
you wanna know about the current Abortion-Right Chaos), this is for you.
@@reesetorwad8346 his name is Vernor not Vernon. I've read two of his books. Both excellent.
@@anthonymorris615 Whoosh!
@@reesetorwad8346 oh haha 😄
After having studied evolutionary development on earth a great deal, my current hypothesis for a great filter is atmospheric oxygenation.
From our current understanding of the evolution of photosynthesis, turning sunlight into biologically available energy occurred multiple times in different organisms, of which chlorophyll is only one option. In fact, there is a hypothesis that chlorophyll (and thus plants) are green because the developed in the shadow of purple photosynthetic bacteria (which are still extant), where no green light would be, so they developed to absorb the remaining red-blue light. The interesting thing about chlorophyll however, is one of its waste products: elemental oxygen. To most life at them time, oxygen was toxic as it is so affective at oxidizing chemicals that it would interfere with its metabolism. But a few lucky organisms were able to use it to make use of it to develop far more efficient catabolism. Anything that you would call complex life, eukaryotic or multicellular, uses aerobic respiration (or had aerobic ancestors and secondarily lost their aerobic abilities). It is likely that without the over abundance of such a powerful oxidizer in our atmosphere, life would be relegated to unicellular prokaryotes.
So if another planet forms it’s own life forms, and their main way of synthesizing energy doesn’t create such a reactive byproduct, would complex life be able to evolve as often.
Of course, this is just my thoughts. I just want to get this idea I had to somebody who is actually looking into the great filter, since I’ve never seen it talked about in these discussion. As always more research is needed.
Edit: I corrected my backwards explanation of color absorption in photosynthesis. Green plants reflect green light, absorb red and blue. It doesn’t change the whole thing, but I did see that many in the comments got held up on this admittedly incorrect fact and I apologize for my lack of in-depth reviewing of my internet comment.
Remember that colored pigments like Chlorphyl are the olor they are because they DON’T absorb much of that wavelength, they reflect it instead. So the purple bacteria didn’t absorbs most wavelengths of light, including green. and Chlorophyl absorbs most wavelengths, including purple, but _not_ green.
I have read that one reason chlorophyl might be so common even though it dosen’t absorb one of the more abundant wavelengths of light (green) is precisely because of the abundance of green light. If plants tried to absorb as much green light as possible, they would absorb too much energy resulting in damage their cells. This is why green-absorbing pigments like red, brown, and yellow are produced in only limited amounts.
This would be interesting because if your hypothesis is right, we should still see biospheres on other planets. Just not Oxygen based ones.
So if this is correct, it assumes life isn't that rare, but Oxygen based life/atmospheres are.
Of course, there are still billions of potential planets out there, with who knows how many chances for life like this to form, so it's still a numbers game. But your idea should be at least testable when/if we can ever get spectrogram readings from exoplanets.
@@samiamrg7 Yeah it's supposedly like melanin in humans. It protects plants against getting what are effectively sunburns.
Oxygen is ridiculously abundant in the universe, behind only hydrogen and helium. So it's probably not much of a bottleneck, especially if it's so beneficial to simple early plant life.
One correction: most photosynthesis involves visible light. Some UV is involved, but plants can thrive just fine on artificial lighting that does not include any UV.
Plants do absorb a lot of blue light though, so a sufficiently cool red dwarf might still be a problem.
Thats photosynthesis on earth like conditions, red dwarves may have plants that look black
@@albert6157 Wouldn't they be more brown? Sameish color I guess
@@sitfish1113 they are black because they need to absorb all the light they can get whilst emitting as much heat as they can, so most likely they will look black. Brown is prossible too but that means they must have an alternative that somehow makes them absorb light more efficiently if brown is the case. Especially with atmospheric scattering of light, there wont be much light energy to begin with. Very likely they'd switch to a mixture of both chemosynthesis and photosynthesis. Or maybe they use heat catalysed reactions, and exploit heat directly.
Photosynthesis can use far-red and infrared too.
@@albert6157 like how ur thinkin...they would be a darker violet that could appear black dependin on lighting
Dont space travel tho...its a trap
Videos like this made me wonder, if us humans manage by some miracle develop FTL travel, and find a primitive civilization, would we protect them? Or doom them?
we are doing that right now, why wouldnt we do it to people on other planets?
Hopefully humanity would have matured by then. But currently, just look at how we treat non-sapient sentient species, we slaughter and devour them.
depends if the planet has valuable resources
Could a significant portion of even the sun-like stars in the habitable zone of the Milky Way be ruled out due to being in globular clusters, where radiation and perturbance is more likely? Or maybe those are mostly already not in the habitable zone?
Even if they are in globular clusters, there would be far enough that the radiation from other stars won't reach them as in most of it would have dissipated before it reached the planet or star system.
No
Can’t be ruled out per say… but as they are usually very planet poor, the chances do get less likely simply due to that
there is a chance life could exist in a globular cluster but its unlikely as the stars are much closer together.
so that could mean a planet could get ejected from the system by another star or be destroyed if a nearby star goes supernova.
0:14 - Most of us? Haha, now I feel left out.
Mentioned more than once but not answered at least superficially: Why does high star metallicity cause more giant planets?
Here is my opinion on it based on all the space videos I watch:
To become a planet you are stealing a bulge away which would have otherwise ended up in the main star. To become a bulge you need a headstart and heavier element are more likely to provide that headstart. More the heavier elements away from main star bulge it would result more planetary objects. And collision between them would form bigger planets.
Again just my guess.
Science nerd opinion, not professional opinion: Amit hit on one key - the more "heavy" elements, the more planetesimals can form, thus more heavy planets. Equally important, among those heavy elements is a greater abundance of iron, which provides atmospheric protection with a magnetic field. In addition, the magnetic field of the star will tend to draw more ferromagnetic element inward, meaning the planets forming in the outer edge of the "terrestrial" zone are likely to get to the size needed to become gas giants. This will disrupt terrestrial planet formation.
Metallicity simply refers to the amount of material that is heavier than hydrogen and helium. In the core accretion theory, gas giants such as Jupiter and Saturn first had to obtain cores of roughly 10 earth masses before they could start accumulating hydrogen and helium. More material around a star would lead to these planets forming in a shorter time frame. Once one or more gas giants are established, they can dictate the growth of smaller planets as they migrate towards and away from the host star.
Mass.
@@AdamBoozer That doesn't explain it. Metallicity measures the fraction of total mass that's heavier elements. It doesn't tell you anything about the total AMOUNT of such systems - in other words, their "mass". You can for example have high metallicity in a low-mass protoplanetary system (say around a recently-formed red dwarf system) and low metallicity in a high-mass system (e.g. around first or second generation giant stars).
There is just so much depth of expertise to the PBS Team. Thanks so much for sharing with us.
Honestly, I think the Fermi Paradox can be entirely explained by the vastness of space and the slow speed of light compared to the size of the universe or even galaxy.
I think even scientists seem to somehow underestimate the huge distances and the vastness of space. Even if our galaxy contained life which is on the same technological level as ours, we wouldnt be able to detect it. Our own "radio bubble" just barely stretches out what, like 100 light years? And the signal is probably so weak by that distance that it is basically impossible to detect.
We just started detecting the first exoplanets the last couple of decades.. and they are all very close to us in galactic dimensions.
Space is just too big and everything is too far apart for us to ever detect alien life. This applies to our galaxy. Other galaxies are even more unlikely to be accessed by any of our sensors, and we certainly will never be able to travel there.
Can anyone make a good rebuttal to my arguments? I am genuinely curious if I have a thought error here.
I tend to agree. It takes light a full year or more just to entirely leave our solar system.
Your argument is reasonable but not ironclad, due to the antiquity of the universe. At our current level of technology and progress, unimpeded by extinction, we should be able to colonize the galaxy in about ten million years. The Milky Way is far more ancient and has had enough time preceding our solar system for this to have already happened. But your ideas are valid and probably contribute to the solution to the paradox.
This is exactly what I’ve always thought. Even if there were super advanced civilizations out there I still think the massive distance between us makes it physically impossible for them to reach us and vice versa. It’s a bummer to think we likely will never learn about other life out there but it’s cool to be so sure that there is.
They are here for a long time. I have seen their crafts..together with three more people. The Navy admitted in Congress.. they are not from here.
Check out a paper "Migrating extraterrestrial civilizations and interstellar colonization: implications for SETI and SETA" published by International Journal of Astrobiology, Cambridge University Press. It discusses how extraterrestrial civilizations may travel from their home worlds to the Solar System and other planetary systems.
Goldilocks and the Three Galactic Zones.
"This one's too metallic. This one's not metallic enough. But this one's just right."
Your description of the sun being an "ordinary" G-type reminded me of a paper published within the last year. It detailed a study of the activity of around 20 G-type stars, having approximately the same age of the sun, over a few years and found that the sun was far less active than any of those observed.
Hardly a smoking gun as, while we have a few centuries of sun spot data to directly support the sun's activity and other methods to indirectly support it (e.g. ice cores etc) compared to only a few years of data for the other stars. Combine this with the observations being only a flash in the pan compared to the age of the stars and the fact that only a relatively small population of G-type stars were studies, and the results are of tenuous importance.
However, the study may be the first to show evidence of the tantalising theory that our sun is also unusual and played a big part of our success. I also believe that even prior to that study it had been a long standing hypothesis that our sun may be underactive compared to the majority from observations of a diverse range of stars being more active than sleepy ol' Sol.
Or is it that active stars are more likely to be caught by telescopes?
@@amit53shukla I don't think that is it but I'm no expert. The activity they are trying to measure is that of the stellar wind events driven largely by stellar magnetic fields near the surface of the stars (e.g. flares, coronal mass ejections). The stars are far brighter than any ejections so their visibility doesn't change much. In fact, I think they might be slightly darker. This is very different to the "activity" of neutron stars and black holes which can become immensely brighter when active.
From memory the study looked at the number and/or the percentage of surface coverage of sun spots on the 20+ G-type stars. From observing the sun we're quite sure that flare etc. activity is proportional to sun spot activity.
The main issue with drawing any solid conclusions using that study is it's relatively short length (2-3 years from memory) compared to the huge lifetimes of the stars and small sample size. For comparison, the milky way is estimated to have approximately 20 billion G-type main sequence stars from a quick google search. Ultimately we have only recently been able to start observing other stars in high enough detail to make these observations and it will take many future observations (and probably increased automated data analysis if you want to scale it up to millions of starts) to confirm/ refute these observations.
More active Stars than ours would simply push the habitable zone further out! It wouldn't simply mean there's no habitable zone altogether!
@@aarongoodwin4845 That's not quite how it works. The "activity" is stellar weather, large emissions of charged particles accelerated to high speeds and these literally erode the atmospheres of planets.
The activity doesn't correlate to the radiative emission of a star in a linear fashion i.e. it could be a relatively cool star so liquid water could only form close, but, it may also have awful storms that strip any planets in the habitable zone of atmosphere.
In fact some of the most active stars observed are relatively cool with red dwarfs being very active for at least a few billion years. It is hypothesized (using computer models) that this activity will decline with age but that's on time scales close to the age of the universe so it is difficult to confirm as none that we can observe easily are near that age.
That is one of the reasons most astronomers believe red dwarfs are unlikely to be habitable, in combination with the necessarily close orbits causing tidal locking, any terrestrial planets will certainly have their atmospheres stripped like Mercury.
Disclaimer though, when discussing the "habitable zone", astronomers are only speaking about Earth-like habitability. The likelihood that we will find other life outside of the habitable zones is still very high. It is just unlikely to resemble life on the Earth's surface but may be closer to deep ocean life on ice worlds or something we can't even imagine. We focus on Earth-like life simply because we can't reliably predict what to look for otherwise as we have no examples to base any assumptions on. We are still looking though but it is more difficult not knowing what to look for.
@@Grim_and_Proper Well it's a good thing that you commented above and clarified that you are Not an expert!
"Is this why **most of us** have never seen aliens?"
Blink. blink.
What are you hiding, PBS?!
the moment moya's name got mentioned all i could think about was farscape living ship moya
intro plays "my name is john chrython an astronaut,radiation wave hit and i got shot through a wormhole,now im lost in some distant part of the universe on a ship,a living ship full of strange alien life forms,im being hunted by an insane military comander and im doing everything i can,im just looking for a way home
If the estimate of 200 trillion galaxies is correct, then advanced life could be as rare as only one species per one *billion* galaxies, but that would still mean theres 200,000 forms of advanced life, but would be so far spread out that our likelihood of finding it is virtually nill. I dont think the Fermi Paradox is really a paradox, I think its simply our brains inability to fathom a universe so large, that even if well populated, would look completely barren to us.
This only works if you assume habitable planets and abiogenesis are /extremely/ rare. In which case, you then have to answer /why/ it's so extremely rare.
Your example doesn't really work. The numbers are just too obscene.
The problem with your argument is that it assumes Earth/Life is special. **Why** is life special then? You haven't really answered the Fermi Paradox. All you've done is move the great filter to abiogenesis or some other early process. I don't think you understand what the Fermi Paradox is if that's your argument. The Paradox doesn't say there has to be alien life out there and that we just don't see it, all the paradox asks is why there is no other life we've noticed yet.
Either Earth is extremely rare (and we know planets like it aren't), abiogenesis is extremely rare (we don't know), intelligent life is rare, or there is some great filter that every technologically advanced civilization encounters that prevents it from becoming galactically known.
All you've done is moved it (the filter) from the last option to the one in the middle. Which is one scientists are already contemplating.
And I really want to drive home that the odds of life forming are independent from how many galaxies there are. The difficulty/rarity of life is independent of it. If you have a million coins and flip them all, the odds of getting heads or tails on one coin is still 50/50, adding more coins doesn't change that. Same here, adding more galaxies doesn't make the formation of life less rare in your example. The odds of life forming would still be astronomically low.
Basically, why is life so rare? That *is* the Fermi Paradox. You're literally just describing another version of it. You just so happen to believe that life forming at all being rare is the answer.
Edit: not to mention that "well populated" is doing an incredible amount of heavy lifting in that thought. It's only ""well populated"" because you think 200,000 is a big number. If only 1 in 10^9 galaxies has any kind of life in it whatsoever, I wouldn't call that well populated. That's very very sparsely populated.
@@nexaentertainment2764 200,000 is still “well populated” when the alternative is 1 from the perspective of many in your species.
I think that the idea of the Great Filter should be seen as a number of filters, each stage decreasing the chances for that particular planet to bear intelligent life. The chances for intelligent life as we know it to evolve must be astronomical.
Given our past record of predicting what's out there it seems improving able we would guess this one or be able to confirm it. Space is really big. I mean really big.
@@nexaentertainment2764 I dont think abiogenesis is rare, I'd be willing to bet simple life starts wherever its possible, I wouldnt be surprised if we find it in the waters of Europa or Enceladus . That simple life being able to evolve into something advanced like us could be quite rare though, simply due to the sheer number of specific things that likely have to occur to make that happen, but again in a universe this big, with as many possibilities over as many years, rare becomes a bit relative (200,000 is big compared to 1).
Is it true that Earth’s moon could potentially me the reason why life was able to emerge on Earth? It’s rare for an Earth-like planet to have a moon as big as our own, and we only got ours from some sort of perfect collision. Could the way it affects Earth’s orbit and rotation and tides somehow be the key that explains how life could only emerge here?
I was thinking of this the entire time myself.
I remember hearing that the moons stabilizing effect on the Earth may have been integral to the development of life here.
Yeah the moon is super rare, it's essentially an extra planet that earth captured during planetary formation, and the exact sizing and energies required that resulted in a stable system without it ripping apart or ejecting are colossally rare. We also know the moon is integral for early life formation, and many view it as a great filter for very early life formation
I recall from my youth an essay by Isaac Asimov where he explored this theory: that only a planet in a sun's habitable zones AND with a massive moon might be able to support life.
Space Time got an episode on that, that'd fall under the Rare Earth Hypothesis, and yes the massive moon is a significant factor in that hypothesis due to it being massive enough to form tidal pools
How do the spiral arms affect galactic habitability? I mean, if the core is problematic for being too star-dense & outskirts for being too matter-sparse, should have lesser versions of same issues depending on whether you're closer to an arm's "spine" or to being out in the "empty" areas between arms.
As well, what's current best guess on layout of dark matter in galaxy, and how IT might disrupt habitability?
It's been 2 years, but the Milky Way has LESS dark matter than normal. Usually they get disperse by collisions, and we have a some dwarf galaxies that orbit and collide with us. Even if dark matter has 0 interaction for fusion, it's gravity could cause stars to crunch harder, and burn more violently. I'm interesting in some of the sparse solar systems in clouds, which surely have some stable suns, without risk of interference... unless debris is necessary to life (note, a massive, massive amount of our metals came from collisions, and the moon)
The Fermi "paradox" is founded on the rather presumptuous notion that life forms can ever have the means and motivation to have the kind of impact on the galaxy that would show up in the night sky.
Much more likely shunting around stars for convenience is just not viable, and I'm tired of people pretending otherwise.
I like to think that lots of life has popped up in the habitable zone, and then just goes extinct when the star eventually leaves it, like ours eventually will.
You LIKE to think that? That's so depressing!
@@theslavegamer That's the point. Life is meaningless because life and the universe will die. It is a very depressing realisation, but the truth. I try not to think about it and try to live happily and be kind to everyone. I think that's the only way to go about it tbh
Question 1: Are there habitable zones at larger scales? Galaxy clusters? Superclusters? Observable universe?
Question 2: Has anyone calculated a temporal habitable zone or, better put, habitable time periods for the solar system, galaxy, or universe? A habitable time period would be the window of time during which life may develop, i.e., from the earliest life may originate to the latest it may survive.
I haven't heard of any events that can have an impact on life at the intergalactic level the way supernovas and quasars can impact life on the galactic level. I think, generally speaking, galaxies are exempt from extra galactic conditions affecting their ability to support life.
Maybe galactic mergers but even then, as I understand they happen rarely, and aren't that catastrophic so it'd be difficult for that to constantly prevent the emergence of higher life forms.
Also, the only thing I've heard regarding question 2 is that life is less likely to form the younger the universe is, and more likely to from the older the universe is. Something about stars having higher metallicity, and there being a greater abundance of elements to form life from as the universe gets older.
The Fermi Paradox is probably solved by something mundane, like phosphor levels, combined with one of the popular ideas about the super rare events in the evolution of life (like the mitochondria becoming apart of another organism).
One mundane solution to the Fermi Paradox is that somebody has to come first, and we're it.
@@Nukepositive I mean we can't rule out the possibility until we find other civilizations, but it's pretty similar to saying that the universe is empty and we're all that there is. It's arrogant. Humans have always liked to think that we're more special than we are, but we could go extinct today and the universe would go on just the same
@@Nukepositive Yea but then there is this pesky question of why now ? As we heard it, many suitable star precedes our sun, assuming that life emerges with the same rate, we really shouldn't be the first. Then again, this problem is hard because it contains way too many unknown variables.
In another life mitochondria would not be needed. Maybe even oxygen metabolism wouldn't be necessary. In absence of competition from oxygen-using organisms, other type of metabolism may come to the forefront, maybe even some which is impossible in our Earth life.
Interesting that you haven't mentioned evolution of oxygenic photosynthesis. I am actually a researcher, and I can say on Earth this evolution was one unlikely event upon another.
@@Nukepositive or that "space colonization" is impossible, and purely our childish fantasy
Two things. First, there's no surprise at all that we are tightly tuned against our environment, because that is precisely what evolution does. Second, we need to consider not merely great _filters_ but great _alternatives._ Are there other, more favourable, things for life to do than build technological civilisations? We might be “alone” because we're the _unlucky_ ones, who have not thought of, or not been able to achieve, some otherwise obvious alternative(s).
Evolution only appears to be directed because of the point from which we view it.
Yes, evolution tends toward an environmental nitch but the environment has to be finely tuned in order for life to develop in the first place. The fine tuning problem cannot be explained by evolution. There are dozens of physical constants that are set perfectly to allow life and if any one of those constants were even a little different life could not have started. So talking about evolution is kind of irrelevant because without a fine tuned environment life could not start it's evolutionary process.
Technology is merely the creation of methods to increase probability of survival. But technology requires (first) communication between individuals: language and (second) communication between generations: writing. Why have primates, over time, increased intellect? Our bodies allowed it. In other mentioned species, increased intellect doesn't add to individual and/or group survival. What could human genius level IQs do to advance elephants, orcas, dolphins, birds, etc.? Our brains could increase in size because our heads sit on top of our bodies. We evolved hands to grasp fruit. Binocular vision to keep from falling out of trees. Non-primate species are too deeply locked in by their biological inheritance to physically change in ways where intellect has advantages.
For a non-primate entity capable of using intellect to come about, there would need to be a major catastrophe like that 66 million years ago where genetics could again create new lines of evolution the way mammals which existed during the era of dinosaurs were able to diversify after the KT extinction event.
The reason dinosaurs dominated the planet was oxygen levels fell. Dinosaurs, too, were a sideline lifeform alongside mammals, reptiles dominated. But dinosaurs had developed a more efficient breathing methodology than mammals so when oxygen levels fell (down to10-12 percent) dinosaurs could get larger but mammals had to decrease in size just to survive. When oxygen levels returned to normal, dinosaurs were simply too dominant.
@@acetate909 Yes, this is the common argument, but it is almost always approached from the viewpoint of “what is the chance of the fine tuning that _we_ have evolved for” rather than “what is the density of evolution-supporting points in the mathematical parameter space”. I'm not saying that we yet have the mathematical tools to address the latter; merely that the former is fallacious. What proof is offered that other tunings provide no mechanism for evolution?
@@liberalrationalist8905 Doesn't that sound just the teensiest bit racist? You'd only need one friend who's an octopus to persuade you that you don't have to be English to have culture. Um. What I'm trying to say is, you've provided a backstory for yourself, and assumed that this backstory is what makes you superior. But the former idea is merely an emotional justification of the latter idea, not a condition for it.
M
M
and & ujuyatt
One issue that's always looming large over "where are the aliens" questions is that we've only searched a teeny, tiny area around our planet. It'd be like being on a very small island, not finding any other life on it, and conclude that there is no other life on the planet.
what we look for are, techno-signatures of super-advanced alien civilizations to which the galaxy seems very devoid of and so we conclude we must be alone in the galaxy otherwise they would have already colonized a huge chunk of the galaxy.
@@fugslayernominee1397 how would we find those signs? If a super advanced alien race exist right now but they are 1000 light year away, and we point our telescope at their location right now we still would not know who they are because any signal that is given off would be from a 1000 year ago.
@@Abluemoon9112 Indirect ways (i.e. there should be type 2 civilization s existing already that should be making Dyson's spheres, meaning also missing or constantly dimming stars. So far, we haven't detected any.
Also, Dyson Spheres are so resource intensive that they produce so much radio waves that rival a star. 1 such system should be detectable by seeing a very high radio wave with very low luminosity.
@@Abluemoon9112 Galaxy is more than 13 billion years old and even if we minus first few generations of stars, that still leave us with so many stars that would have spawned an intelligent life if it were this common as spawning every few thousand light years.
The whole point being; if intelligent life is so common that it emergence every few thousand light years then what makes them stop advancing any further? If there is an intelligent life in few thousand light years of us and only started giving off techno signatures just now then given geologocal time scales this must be a one heck of coincidence and should suggest intelligent life is a lot more common and we should be detecting these kinds of techno signatures every so often from other parts of the galaxy and from other civilizations that are lot more advanced and older that the one you mentioned, this only makes things worse.
@@skybattler2624 again if a Dyson sphere exist now it does not mean we would see it. We can only see in the past not the present. So an advance alien civilians has to existed in the past for use see it now.
A Dyson sphere is also just a hypothetical structure that we as humans think an advance civilization show have.
Assuming that “life” HAS to be similar to ours, maybe in other places another form of life doesn’t need same proprieties we do
I think part of the point is that, even if we assume life *always* needs the same conditions it needs on Earth, there's still an ample amount of planets that should be able to fulfill those conditions.
The only life that has to be similar to ours is life that arose in similar conditions to our planet.
On a much colder planet, ammonia could end up being a life-solvent instead of water, which leads to completely different habitability concerns.
The thing is : we're really far from taking every parameters into account and I actually think the Fermi Paradox isn't a paradox at all, or at least only if you see it from the perspective of astronomy and physics as we just took the conditions at an astronomical scale for life to emerge but there's so much more to consider.
For example, the fact the core of the Earth is liquid AND solid iron allows us to have a strong enough magnetic shield to protect us against the dangerous coronal mass ejection, there also is the fact life took a very long time to create an intelligent species on Earth, about 3.5 billion years (maybe even more, as far as 4.5 billion years), so it's not something we should dismiss as it has its importance into the equation. Assuming, after all of that, there's still suppose to be a lot of life in the galaxy, we didn't mention the possibility of their auto-destruction, which could explain why we didn't see any of them yet, something we may face one day too as an intelligent species.
So, there are so much things we have to take into consideration before drawing any conclusion.
Good point - though we have already faced self extinction. Our luck will run out .
@@tim40gabby25 Noo, we're far from it. With the first nuclear weapons appearing, we all feared that in would eventually end up in a massive and world wide nuclear war and we would create a nuclear winter on Earth, which would make the Earth's surface unlivable.
So far, nobody shot and was crazy enough to shoot even once on another country or civilians since the incident in Japan with Little Boy (or Fat Man, I never remember), which made us realize the immense power we had in our hands.
That was the first cap for a long time we needed to check : see if our level of hostility toward our own species could create an auto-extinction with powerful enough weapons.
Now, if you're referring to the global warming, we won't be extinct for that, it's not even a survival challenge for humanity. Though, it is a stick in the wheel of our ambition to constantly want to improve our civilization and our comfort of life.
@@rigierish3807 You describe what has not happened, not what might. 50 years not pressing the button is not a long time period. Are you confident that some person will not press sometime in the next 10,000? 50,000? - both are blinks of an eye in geological time.
Very good points here. H. sapiens needs mass student exchange, with empathy social clubs, instead of huge arms research in every technological power.
@@tim40gabby25 (sorry, I didn't see your answer, I only noticed because there was another comment that popped up in my notifications)
I’m pretty confident due to the fact only few decades of observation is necessary. And the reason I'm only considering the first decades is because self-destruction is only a matter of knowledge and the more time passes, the more we have knowledge on a subject.
When we first created the ozone hole in the atmosphere because of a component in refridgerator, we made the mistake but realized it later and since then, we started to be more careful of the impact of components we use in our products on the environment. It is very unlikely now that we could make such a mistake considering we know what we are able to do.
Nuclear weapons are the same. When we shot the first nuclear weapon, we realized our mistake and how dangerous it can be to use them. As we know the danger of such a weapon, we won't use it anymore and will proceed to be extremely careful with it since this day. When the first nuclear weapon was created, we knew it was powerful but we didn't know how much. Now, we can make simulations of our last most powerful nuclear weapons and we know exactly the extent of our power thanks to it. The more we advance, the more we are afraid of our power as a civilization.
That's why the likeliness for it to be used will constantly decrease the more time passes. As crazy as it sounds, the most dangerous times - that is when it was the most likely that another nuclear weapon could be shot - was few years after Little Boy was shot. And indeed, that's what happened because few days after Little Boy was shot, Fat man followed.
The video omits a key finding of the Kepler mission about the stability of our sun comparison to other stars, which makes it quite rare
See the problem I take with this video is our Star is provably unique on a galactic scale and potentially unique in the observable universe in so that it is abnormally quiet for a star and not just for G type stars but of all star types our special little star produces far less solar flares than most others observed. (Edit: typo)
Surprised that the abnormal quietness of the Sun was not mentioned again in this video.
Also that sapient life will rapidly over-run the ecosystem and destroy itself... and even if it doesn't entirely, the next time around there will be no huge "easily accessible" hydrocarbon reserve to tap.
@@dw620 I find it strange because they've done several videos on similar subjects where they have mentioned it and a video dedicated to the quietness of our sun so I'm really confused by this video it contradicts a lot of evidence to argue our star isn't special.
Our star is demonstrably not unique in the galaxy and is not close to being so. It is pleasingly quiet, but there are billions of others of comparable profile. This means the flare level is quite low - what is rare in a population of hundreds of billions is still billions in this case. Keep in mind that our star still produces flares and that flaring at substantially higher levels does not at all rule out the development of life of all kinds.
I think the most likely reason why there is a "Fermi Paradox" is due to the massive distances between stars. It's just mind-blowingly far. Add to that the seemingly "perfect" conditions necessary for carbon-based life with water as an organic solvent (the only type we know works), the time scales required for life to actually advance to "intelligence" (which took billions of years on Earth), and the fact that just because a species could spend a million years sending probes around the galaxy doesn't mean it will see any good reason to may not give any answer to whether intelligent life exists, but may give a good idea of why intelligent life has never been detected outside of Earth.
When it comes to this galactic habitable zone, I am curious what it looks like a billion years ago? Two billion? It should shrink quite a bit going back in time. It's entirely possible that Intelligent life has only had less than a billion years to pop up anywhere in the Milky Way when all other variables are considered, even considering the age of other "habitable" stars. We could be one of the first honestly. Or we could just be way too far from any others to ever reasonably detect them.
The activity of any species older than us by a few million years should be easily detectable.
There are some underlying assumptions and reasoning as the the following premise's that I can go into but as for the probe reasoning.
-Every space fairings species wants to send probes to every star in the galaxy. (Its a matter of survival at minimum not just curious/exploratory species. When probes take minimal resources vs the threat of a species evolving that wants to wipe you out you send probes just to make sure. They have to always be watching since basic smart animal to sapient space faring race takes a very short time.)
-Such probes if self-replicating can cover the entire milky way in under 500,000 years and more likely in under 200,000 years. Given that it only takes a 50% light speed sail to do that.
-The evidence of such machines filling the galaxy would be difficult to miss. Especially given the constant need for upkeep, maintenance and planetary surveillance.
-Even if somehow such activity was hidden from us; it is unlikely that a species would both moraley align with us AND also wish to hold off first contact till a significantly later date than now given the level of moral injustice their technology and guidance could correct.
-Any species that is moraley unaligned with us would have simply destroyed or contained us by now as our mere existence poses an existential threat to them given we cannot coexist.
Thus no extent sapient species exist within the milky way besides us.
We may just have an insufficient technological level to detect other intelligent life.
"... Which explains why most of us, have never seen aliens" aaaahahaha well played, brother 😉
Less mythology, more science! :)
@Stovepipe Downtube sure, I love and value mythology too, but I come to this channel expecting all science!
@Stovepipe Downtube no, but this channel revolves around science. Can’t really see your issue!
I love all your episodes, and the crossover was really unexpected and fun!
I generally think the Fermi Paradox isn't much more than an interesting thought. There's a million potential reasons why we might not have detected any signs and only one of them is "no aliens here". Still a good hook to consider reasons we might be the only advanced lifeforms in our galaxy.
I think it is fair to say that the Fermi Paradox is more than an interesting thought. It presents a real, specific, falsifiable prediction based on the null hypothesis. It's not just the total absence of any technosignature, but one very specific technosignature that would be impossible for us to ignore. As mentioned in at least one other video - to which this one alludes - even assuming that it is impossible for any technology to match, much less exceed the speed of light, it would still take much, much less than a billion years for just one species to colonize the entire galaxy - once they have developed the technology to mass-produce spacecraft capable of achieving relativistic speeds. After 4.5 billion years of our solar system's existence, we're not there yet, but we have no reason to believe that it'll take us 1 billion years to get there. It even seems that we'll have the tech to get started on that millions-of-years-long effort within the next thousand years. Based on the constraints presented by this video, there seem to be about a billion stars that could've produced a technological species such as our own, and *most* of them have plausibly had a "billion-year head start."
The null-hypothesis, then, is twofold: first, that stellar systems capable of producing human-like intelligence is common, and that it should only take 4.5 billion years for that intelligence to achieve our current level of technological development. And the seemingly *necessary* consequence of that statement, given the constraints established in the video, is that *our own* stellar system should have been colonized before we even existed. This means that we likely would have never evolved, since they would've filled the same niche in our biosphere that we do. The question posed by the Paradox is "why are we here instead of them." We've tested that prediction and falsified it - we exist, Q.E.D. The less extreme form of this prediction is that they wouldn't have settled every stellar system, but they would have probed them - extensively (and are probably still doing it). If so, then we should expect to find considerable evidence - derelict spaceships on the Moon, Mars, just floating around, etc (not necessarily crashed, but even just abandoned or decommissioned) - or some evidence of past mining activity on Earth, using technology equal or better than our own. But we haven't seen anything of that sort even though we've explored quite a few parts of our system *really* close (especially the parts that would likely be most interesting to them).
This was, of course, even more perplexing in Fermi's time than ours, since the known constraint wasn't 1 billion stellar systems - since less was known about the nature of stars - but rather over 100 billion. You're right that there are plenty or resolutions to Fermi's paradox, but all of them fall in the following 4 categories. The first two are that one component of the null hypothesis is wrong: either intelligent life is so unbelievably rare that we are actually the first species of intelligent life to emerge in the entire galaxy (or at least so incredibly rare that *all* such species are extremely close in age - in cosmological terms - to us) or it is unimaginably rare for intelligent life to reach the point we have in *only* 4.5 billion years. The third is that something *necessarily* stops *every* species from accomplishing this task before they reach the tech level to do it. This would mean that something stops intelligent life from doing what we observe most life doing - filling every single nook and cranny that they possibly can - and even what our own intelligent species always seems to do - gathering as much data as practical about its surroundings (and also frequently expanding the scope of "as practical"). The fourth is that more advanced intelligent species are simply *really* good hiding their presence *and* that *all* (or nearly all) of them actually choose to do so - not just every species, but every member of the species that has any way of intentionally or accidentally revealing the existence of the species to us. Of course, not of these, as I have expressed them are mutually exclusive. Invoking all of them, might involve making fewer assumptions.
TD;LR: Our available evidence suggests, that, not only *could* intelligent life more technologically advanced than us it actually *MUST* exist - statistically speaking. It also *MUST* have either prevented our own existence (whether accidentally or intentionally) or provided overwhelmingly strong evidence of its existence. This has not happened. Therefore *something* must be wrong with our dataset. This is more than a mere *hook* to the wild idea that we might be alone in the galaxy, rather it is to astrobiology what the "crisis in cosmology" is to astrophysics or similar to the fact the General Relativity and the Standard Model of quantum mechanics both (seemingly) predict too much to be wrong yet also (seem) to contradict each other (leading to the search for a "Theory of Everything" that reconciles the two). It could probably be said that solving Fermi's Paradox is the main objective of the entire field of astrobiology right now.
NOTE: This comment ended up being much longer than I thought it'd be, sorry about that. Also, it was probably incorrect for me to speak of just one null hypothesis with two components. It is probably more correct to speak of 2 null hypotheses; I started writing this with the statement of one null hypothesis, and I decided to roll with it because going back and changing it was too much trouble.
@@jeffbenton6183 That was a very long comment. But for me this hypothesis fails on the point that we expect an alien technologically advances species to adhere to a specific way of thinking and acting. Why wouldn't such a species not decide to stay local for as long as possible, only moving as far as they need, a few planets at a time to avoid complete extinction in an unforeseen extinction-level event? Or maybe they don't even mind taking the risk of extinction, preferring to stay local anyway. No species needs to settle galaxy-wide. No species needs to want to make contact with other advanced species. What if they are inherently against colonizing at all? The fermi-paradox just does not take into consideration that a species may not have the same ambitions as 1900s european colonialist.
@@JeiFaeKlubsWell said! In addition, I think that it is clear at this point in human history that being a colonizer is not a sustainable mentality for a society anyways, as it requires society to ignore important values like environmental protection in the pursuit of expansion and capitalization. If we want to apply this mentality to aliens then we also have to grapple with the fact that the desire to colonize the galaxy very well could be the critical factor that makes it an impossibility for an alien society to do so as it requires them to value expansion and capitalization over sustainability of their own society.
Because most of us have lived our whole lives in capitalist dominated countries, it's hard for us to truly realize the profound unsustainability of colonizer-capitalist society.
@@jeffbenton6183 I love long comments and yours was interesting to read, but I can't help but point out how Fermi paradox is total nonsense. What's missing in that model is that we still have no clue how something dead becomes alive, which is basically the most important thing, and proper scientific thinking would be that we can't even speculate about existence of life elsewhere until we figure that out.
For example, it could be that certain mix of matter needs to be at specific temperature, exposed to specific dose of radiation, and those conditions need to be true for specific amount of time for life to even have a chance to emerge. Or perhaps life emerges as soon as there is liquid water on the planet for long enough time. You can see how some of these being true would totally change the equation about the possibility of other life in the universe. Of course, we know that the second isn't true, as we are yet to observe life emerging from something non-living. So for objective thinkers there is no such paradox.
@@julius43461 That one has been found, at least for earthlike life. Deep-sea hydrothermal vents produce a continual geologic outpour of organic chemicals. The hot vent in the cold sea means there's a temperature gradient, and as these chemicals cool, they naturally link up into longer and longer chains. We see these form amino acids and then peptides already - the only thing keeping us from seeing the rest of the process in action is life itself. There are families of extremophiles whose main evolutionary pressure seems to be getting closer than each other to these sources, so they can eat the outpour before anyone else does. However, we do see uneaten peptides escape, and it's easy to see from there how this is a rapid dictionary attack on the building blocks of life. If something sterilized the planet of all life, even killing those extremophiles, then there would be random enzymes catalyzing away within an hour. It turns out the RNA world is continuously generated in many places over the planet by geologic processes.
There is a vulnerable point in Drake's equation, but it's at the other end - once technological civilization arises, how likely are we to recognize it? Given we wouldn't be able to detect an identical civilization around Proxima Centauri, and technology branches wildly and builds on itself, it's pretty darn unlikely.
One possible answer to the fermi paradox is that most (if not all) of technological civilizations cause their own demise. It could be that the nature of competition in all life is a deterrent in becoming an interstellar species.
I think that the most issue is time, the radius of interaction from earth since we started sending radio signals is really small compared with the whole size of the galaxy
and if any life did get the singles, they would have to figure out what it is saying and find where it came from to send a response. that is if they can even get the single.
@@somebluestaroutinspace5625 If they want to... How do we know aliens want to find us?
@@QuirkySmirkyIan you don't maybe they don't care for life outside there solar system. I mean there culture is alien to yours.
Isn't the vastness of space and time solution enough for the Fermi Paradox?
Makes it worse, actually.
Not really, the Fermi Paradox is about seeing other technological life. Not about having the capability to travel there.
This is always what I think too. I think even scientists seem to somehow underestimate the huge distances and the vastness of space. Even if our galaxy contained life which is on the same technological level as ours, we wouldnt be able to detect it. Our own "radio bubble" just barely stretches out what, like 100 light years? And the signal is probably so weak by that distance that it is basically impossible to detect.
We just started detecting the first exoplanets the last couple of decades.. and they are all very close to us in galactic dimensions.
Space is just too big and everything is too far apart for us to ever detect alien life. This applies to our galaxy. Other galaxies are even more unlikely to be accessed by any of our sensors, and we certainly will never be able to travel there.
@@CanariasCanariass If there was a technologically advanced race contemporaneous with us, that would mean they're incredibly common, and we should be seeing evidence of the billions of civilizations that evolved over the last few billion years. There's no reason complex life couldn't have evolved as quickly as a couple billion years after the big bang.
@@jeffhoward162
How so? We wouldnt even be able to detect a signal from them if they were like 100 light years away, given their signals are of the same strength as ours. We can only scan such a tiny amount of space for life it seems ridicolous.
Recall all the systems with "Hot Jupiter's"; these system might have formed small rocky planets with oceans but the giant came in and ejected them. One needs a Saturn to go along with the Jupiter. Then the two together help clear dangerous debris but also do not enter the inner habitual zone destroying those vital planets (by stopping their growth or ejecting them.) Then any small planets in the habitual zone can't be too small or its core will cool too fast and no protective magnetic field will exist long enough to protect the atmosphere from solar wind and being striped away. Then a large enough Moon to prevent extreme changes in the planets spin axis/orientation (leads to wild swings in all regions for temperature and light duration.) Just these (and we know more) are absolute minimums for a planet to have in order for large complex life to have time to evolve. That likely takes the 40 billion or so down to well under a few tens of thousands. And the list goes on - as such, wouldn't be too surprised if it turns out there are only a handful of solar systems in our galaxy that are true "Goldilocks" like our system so advance beings could evolve.
I don't think we have not ruled out Super Nova as the great filter. With the discovery of Hyper Nova, we now know that some Nova explosions are so powerful they destroy all life in 25% of a Galaxy like our own. These rare but powerful explosions have finally settled down in our Galaxy to the point where life can exist. It's very possible we are the first.
Maybe intelligent life only exists for such a short time that it would be extraordinarily rare for 2 intelligent life's to exist at the same time AND close enough to notice each other
This is the most intelligent explanation I have ever heard! How come no scientist has said this already? It is almost as obvious as Darwin's theory of evolution to which
T.H.Huxley replied: "How stupid not to have thought of that!". The simplest explanations, Occam's Razor, lifts its head again....
I think the other two major factors about our solar system that allowed complex life to develop are: our Moon and the position of Jupiter. It seems likely that something happened in the early solar system that distributed things in a way that was uncommon, even among similar star systems
Regardless of how strict requirements are for life to exist, it could be literally one in a pentillion [edit: quintillion] and it still wouldn’t be any surprise that we’re in it. We obviously have to be in a place where the universe is conducive to intelligent life because we exist. I think this is called the Anthropic Principle?
anthropic
@@drdca8263 thanks!
@@crsmith6226 it definitely couldn't be one in a Pentillion (cause that's not a real thing), the Milky way is estimated to have 8 billion earth like planets, and the universe is estimated to have around 100-200 Billion galaxy's, back of the napkin using 200 billion thats eight hundred quintillion (8×10²⁰)
@@crsmith6226 I mean, I think there was a paper in 2001 that proposed a consistent way to name large numbers that used Pentillion instead of Quintillion, but it was never adopted anywhere because everyone already used The Conway-Guy system of scientific notation.
@@garionprak7961 dang so I’ve been using the wrong word for it?
Great video! We're learning so much. What a time to be alive. 🙂
Definitely (ﾉ◕ヮ◕)ﾉ*.✧
The series "Zones of Thought" is based around the idea that the core area prevents intelligent life. The region we live in is the "slow zone" is the first where intelligence can develop but further out is "the beyond" where advanced intelligence can develop and in the galactic halo is "The transcend" where things so advanced they might as well be gods live.
Indeed. Imagine what humans will think of our civilization a thousand years from now, if we continue at our current exponential technological pace or greater. Assuming, of course, we survive that long. Now imagine what another intelligent entity a million years ahead of us would think of us. As Sagan so eloquently stated, "they wouldn't". They could no doubt manipulate things in such a way to say, make Venus look as it does. All while hiding in plain site. And living hidden in a physical state we can't even conceive of.
Very good series
Could it not be that the odds of life starting in the first place even in identical conditions are so vanishingly smaller. As I understand we still think it only happened once on our planet , so what if we just got unbelievably lucky.
That may indeed be the case, or any of an unknowable number of other 'great and small filters'.
Our 'estimates' on the abundance of life, or not, have a data point of one. So we are caught anywhere between the mediocrity principle and the Earth being genuinely the only place life exists, there is just no way of knowing and we may never know. FWLIW: I tend to take the view there is nobody out there because for all practicable purposes there may as well not be unless we find evidence to the contrary.
@@charlesjmouse Within the galaxy it's hard to say, but there's no way we're alone in the whole universe... but at that scale it's pretty irrelevant
Something to consider is that after life initially formed on earth any subsequent life genesis would just get erased by the life already on earth
It is rather sobering to consider the fact that Australia isn't trying to kill us very much, when compared to the rest of the universe.
it is also sobering that Earth is not Space Australia.
Australia is much safer than many other places in the world. Australians act like they are the only place with venomous flora and fauna.
Wasn't it found that our sun is unusually calm even compared to other stars of the same category?
Compared to some stars it is quite docile.
Crazy to think that the entire fictional Star Wars “universe” takes place in just 1 galaxy. And there are trillions of galaxies in our universe. Then imagine a multiverse existence and it just blows my mind
Only one species in the history of the Earth has even realized that outer space exists, much less being able to travel through it. Our level of intelligence may be rare.
This isn't necessarily true, there are multiple different animals that use stars to navigate. I suppose it depends on exactly what you mean by realizing outer space exists though.
Not exactly; there have been multiple species of humans, and they were no doubt aware of space in some capacity.
@@NeoCyrus777 there is evidence that some early humans thought stars were just suns farther away.
Yea i think so too it took a long time for humans to exist other animals have done nothing advanced and for most of the existence of our species we where just tribal hunters then we where non industrial civilizations for 1000s of years only in the last 200 years have we really been thinking about aliens in a realistic way.
Arthur, don't forget mice and dolphins!
When your stellar nebula has too much metallicity: "GIANTS! GIANTS! GIANTS! BECOME UNSTOPPABLE!"
The sun being one of the younger stars, with most others being at least a billion years older a frightening thought comes to mind. Perhaps other civilizations did exist, far more advanced than our own, and have already died off and returned to dust. Perhaps the great filter is still ahead of us.
It is possible that to reach mid game you need a specific type of strategy that fails late game.
As nice as the co host was, space time wouldn't be the same without Matt. Watching somebody else present the latest episode made me realize how little I was interested in watching when presented by someone else. Matt makes space time so enjoyable, it won't be the same when you leave.
Thing is that fermi paradox was ACTUALLY solved on 24 february 2022. All emerging civilazations cant agree within themselves and just die in big nuclear wars.
My suggestion for an answer to the Fermi Paradox is this:
Human beings are obsessed with materialistic things and especially technological progress, thinking all this is the cause of happiness when in fact it's not. We're so obsessed with technology as 'the answer' and so egocentric that we can barely even imagine a highly intelligent species which is not highly materialistic, highly technological, and overpopulating its planet.
The truth might be that WE as a species are not as mature, as intelligent or advanced as we like to think. There could be many advanced, intelligent species out there who are contented and peaceful, living in harmony and enjoying the real cause of happiness - inner peace - who have no great need for technology and materialistic life and so aren't easily detected by our tech-obsessed search.
Hopefully, maybe, one day human beings will head in that direction too!
unfortunately, inner peace doesn't solve disease, or house people, or increase the food supply. all those things are done with technology. humans are an extremely primitive backwoods not worthy of intergalactic travel civilization, but that doesn't mean that the answer to life is inner peace, that's the subjective opinion. a lot of what you say here sounds reasonable and seems like it makes sense, but when you think about it a lot of it really doesn't. you should watch some star trek. one thing though, is that if you set your sights a lot shorter, like here on Earth for instance, dolphins and whales and pigs are like all extremely intelligent, possibly even more so than humans. but humans like to compare everything to humans, it's like calling a turtle slow because it can't beat a cheetah or something or it's like giving a dog and IQ test, it's when you compare things on a human centric standard you miss a lot of stuff. so that part of what you said was cool
@@clown134 thanks for your reply but you've really gone a long way off what I said. I never said there's anything wrong with technology or that it couldn't co-exist with inner peace. What I said was the obsession with technology (which is the opposite of a peaceful mind) is causing some problems.
You said inner peace isn't the answer to life, I didn't say that, I said it was the cause of happiness. You can still have medicine, tools, houses when you are at peace - why not? On the other hand if you're saying all we need is technology and not peaceful positive minds AS WELL, then why are there so many new dangers in the world caused by technology, and why do human beings have so much unhappiness and misery still?
Right now the Russians are using superior technology to cause untold misery and destruction in Ukraine. This is caused by greed, arrogance, hatred - unpeaceful minds. So the cause of world peace would not be technology but compassion, loving-kindness, contentment etc: peaceful minds. Humans are nowhere near achieving that yet, but maybe some intelligent civilisations elsewhere have achieved it. That's all I said really. Sending good wishes to you.
@@Clearlight201 It's a common science-fiction lesson that humans never get ahead because they quarrel among themselves.
I love reading the comments after watching the video. Alot of my questions answered there. But I have yet to see any theory that addresses the habitable zones for binary star systems. Certainly binary systems have planets. 2 stars would mean more metal. Aren't binary stars more stable? More light means life could begin farther away from the stars than the Earth is from the Sun.
That's it! I can't take it anymore. I'm starting an 80s heavy-metal band called MetaliCity, and I'm going to use everything I've learned on this channel to make it an _actual_ 80s band by going back in time.
I don't know what is more terrifying: the idea that aliens could have a billion-year lead on our development or the possibility that Earth might be the first planet to host technological life.
Definitely the first. I wouldn't mind humanity becoming what everyone refers to as "The Ancients" or something
@@kuuro_7712 Ay, fellow stargate fan?
@@Rainfall7 Jaffa cakes my bro
I think it would be even more terrifying if aliens did have billion-year leads on development but we still lapped them technologically in 100 years. At that point, both species need to stop whatever they're doing and start asking themselves some serious questions why that happened. Starting with the very real possibility we're in a simulated universe, and that one or both of us may also be simulations.
Also, I think it'd also be terrifying to know that aliens did have a billion-year lead on development but technology stops really progressing at about, say, 80 years from now. Meaning that their head start doesn't amount to anything. That is, there's a real chance that someone alive today will see the last thing ever invented by humans.
I'll pose a question. Imagine that there was only one person on each continent on earth. Now, they are immortal but still subject to the laws of physics and other plants and animals still exists. How long do you think it'd take for 2 people to run into each other?
so.. what is the answer? you post the question, you tell us
@@clown134 I asked the question. What's your answer?
The dynamic star simulation was an amazing piece of VFX! Love the explanations and pace of the video, stellar work.
I'm reminded of a series of short stories by Larry Niven, where aliens contacted us who were galactic conquerors, but all they were interested in were red dwarf star systems as that's the environment they evolved in. Having the ability to keep their existence secret from us, they only came calling because they wanted to use the solar system as a kind of railway station/stopover, with no interest in conquering it.
True
Every "just so" story like this neglects the fact that there should be thousands of alien civilisations out there and only one needs to make contact. It is far more likely that technology inevitably and tragically destroys civilisations and planets just as they begin to explore the galaxy.
@@jimcrelm9478 Naw. My opinion is that the conditions for advanced life to develop on a planet and then develop into intelligence is a very very rare occurrence. So rare that some galaxies may not have intelligent life at all.
@@montylc2001 18Scopii and HIP 56948 are two stars nearly identical to the Sol system in almost every way possible to the point of being almost too good to be true. 18Scorpii is 45 light years away and HIP 56948 is 208 light years away. Scorpii is 1 billion years younger, meaning its still in the primordial ooze stage of life. (if it has life at all). meanwhile HIP, if it has life, is 2 billions years older than us. It seems highly unlikely that HIP won't have complex life. It is unthinkable that in 2 billion years it didn't develop intelligent life at some point. Maybe it did and its long gone by now. (assuming the conditions are perfect for life there). But if they had life, how could a planet so close to us, not have visited us by now? It begs a lot of questions. Maybe there was intelligent life. Maybe a pandemic wiped them out. Or they wiped themselves out. It is just so damn easy to do. Would we even find any evidence of their existence after 2 billion years? So So many questions.
@@FablestoneSeries Earth is rare. Advanced life may be very rare as such is on this planet because of the Moons influence, and the exact conditions of how the moon formed are going to be very very rare. Plus many other factors. Recent research indicates that if Earth did not have the Moon, and the after effects of the moon's formation directly on the Earth not counting tidal effects, advanced life probably would not have developed at all.
A Spacetime episode that I didn't have to rewatch multiple times to get a fingerhold on the physics. I don't know if I should be excited or disappointed.
Both.
had to skip the random unwanted promotion but yeah the rest of the video was great as usual
Shout out to the Zones of Thought concept as thought up by Vernor Vinge.
The book A Fire Upon the Deep is amazing and talks more about why we might not be able to see other civilizations because of our location in the galaxy.
Some of the best space opera I've ever read. Stole some of the ideas to use in MRP type systems ;)
What if there is a 'habitable zone' for spatial dimensions? Imagine infinite dimensions from string theory on up. We find ourselves in a nice spot in the middle.
One concept related to dark matter is of interest here. We could be living in a minority type region of the universe, the "electromagnetic reactive zones". Dark Mater is simply called that as it doesn't appear to react, interact, or produce most (or all) known forms of electromagnetic radiation. Light just moves around it or passes through it without either interacting *think photons are like neutrinos to dark matter*, but Dark Matter does have mass, so that causes problems right there for unified field theories when something interacts with one aspect of space time but ignores another "fundamental force". So what if Dark Matter is not one element, but has variations, elements, soils, stones, compounds, and even living structures. There could be entire regions of space following some of those other dimensions theorized in String Theory that they interact with but we don't, entire regions of space effectively invisible to us and us invisible to them more than likely, but both partially aware the other exists due to detecting the influences of gravity.
@@TheRhuen those other dimensions in string theory are compact dimensions, not full spatial dimensions. Only something on the scale of an elementary particle could interact with them.
what do you mean by infinite dimension, its hard to just understand the like 10 or 11 but infinite!! does that even have meaning ? i heard if there is more or less this universe will get unstable like the laws of physics will not be the same but what do i know i m not a physician i just don't like this kind of infinity it hurts my head
We are the largest universal roll of the dice that has and ever will exist; always makes me think of the Aliens in MIB playing with Galactic marbles.😆
"The Fermi Paradox" is a misnomer. It is not a "paradox", it's a problem. There's nothing paradoxical about it. It should be called "The Fermi Problem".
It's a paradox in the sense the observations doesn't match at all the theory.
Fermi life's equation tell us there should be millions of alien civilizations...and yet we've seen ZERO
If there are other civilizations out there, what parameters would make their AI's to discard the possibility of life in the planets of our sun?
You know AI means "artificial" intelligence, right?
The unfathomable scale of creation makes me think the Fermi Paradox grants statistically consistent authority to any and all factors of the universe to work against us. I believe it to be a combination of everything from technological barriers, chronological barriers, stellar activity or lack thereof, galactic activity or lack thereof, sustainability crises, any and all potential factors will have room to work however they may in a universe large enough for anything to happen.
What I wonder about is tectonic plates, and how much they have to do with life becoming as varied enough to develop into an intelligence high enough to want to explore away from their homeworld.
Seems like the answer to the fermi paradox is that life is very rare, intelligent life is exceptionally rare, technological life is EXCEDINGLY rare, and space faring technological life is all but impossible...especially given time and speed of light constraints. The hurdles are exponentially compounding interest, and Einstein called that the most powerful process in existence. The laws of the universe may make true galactic travel impractical.
We have a gem of a planet. No point in looking any further unless we can learn to sustain this planet first.
That's a guess that supports how you feel, not "the answer." To find out if it indeed is the answer, we have to continue looking outside our planet. Solid evidence is how we get to "is" instead of where you/we are now, which is actually "might."
Seeing this video right now, maybe you can do a video about stars in general one day. A few questions I have about them:
- Is a star basically a planet that was big enough to ignite fusion?
- How do binary or tertiary star systems form compared to regular ones?
Another issue is that our Sun likely formed in a pair, and that’s why Earth is where it is, and Jupiter is not the closest body. The second star dragged our solar system into disarray and moved the rocky planets to the inside and the gas planets to the outside.
Most solar systems have the same arrangement as would be expected, with the largest and lightest closest to their star.
I thought most stars formed in pairs?
@@colonelsanderson That would also be pretty cool, but you would still need the incredibly unlikely circumstances of shuffling that happens with the earth
I would assume that other "intelligent" life is just as good at destroying itself as we appear to be.
What a wonderful episode, Dr. McTier was splendid!! Such a joy to learn from her.
I'm not an evolutionary biologist but I would guess that, with what we know about evolution, it's a process that would favour simple lifeforms. Complex creatures capable of thinking and building structures are not as good at propagating as other simpler lifeforms like fungi or bacteria. That still doesn't solve the paradox, but it's possible that life in Earth is a very rare and fleeting thing, right? Maybe it happens only a few hundreds of thousands of times in every galaxy.
Actually being large and multicellular offers many advantages over simple life, which is precisely why it evolved and flourished. The step from single to multicellular doesn't seem that difficult today as many transitional organisms are observed such as slime molds.
@@filonin2 Again I understand I could be completely wrong about this but wasn't there a significant period of time where the only life on the planet was unicelular? Maybe I need to check again but I remember reading that throughout about half of the history of life on earth, there was only unicelular life.
@@filonin2 Based on the amount of time life has existed and the amount of time it been multicellular it think you have underestimated how difficult the transition was. Also it not possible to have a guess of its difficulty from theory because there is no theory that explains the transition.
there is no paradox. we don't know much about the rest of the universe at what is on other planets. we lack the data to claim anything. It's only a paradox for those who are deluded by too much science fiction.
@@maythesciencebewithyou it was created by a scientist though.
Just phenomenal. You guys do such incredible work. Thanks for another great, informative episode. And LOVED the crossover! Thank you Dr. Moira McTier!
The Outer Rim has always been a difficult place to be. Ask the Hutts.
If you're going to talk about filters, what about one talking about liquid being needed to create life. Point being how many intelligent life forms could simply be lacking technology because they live in liquid. Pretty tough to advance technologically in such environments
Only because humans did not evolve in water. What seems difficult to us could be an obvious solution to a species that has been evolving methods for building and living underwater for thousands of years.
If we never been to the artic we'd think 100 below 0 is to cold for life
The arctic still has liquid water which we have good reason to expect is required. The habitable zone is pretty generously wide (and it's a fuzzy band) to allow for all sorts of variations.
I love the Mass Effect background music!
For those that question life elsewhere..... How many variations of humanoids have been found to have existed on this one Planet we call Earth/Home?
The simple answer: While general life may last for billions of years, I suspect that civilizations have limited viability. They are their own greatest threat. While science can solve technical problems, "advanced" life is short-sighted and morally stupid.
You can't assume that just because humans are short-sighted and morally problematic.
And in case they are the opposite, they'd control their population growth and try to live sustainable lifes on their home planet.
I think you're just referring to humans. To assume that any and all intelligent or advanced life would behave like us is...well, short sighted and stupid. 😆
@@the300club8 Consider the fact that all advanced life has to evolve from single cell organisms... then it seems short sighted and stupid to think that there is the slightest chance for any intelligent life anywhere to evolve from something other than wild active animals, and therefore it's actually wise to assume that practically all intelligent life will have to go through the same technological, sociological, political problems as our does, and considering how easy it is to destroy our environment not only with nuclear weapons its also quite wise to assume that this might be the great filter - being that intelligent civilizations most of the time destroy themselves before they're capable of evolving enough to strike a balance with their environment, leave behind petty interplanetary quarrels in the name of unity and greater things.
We're still a long way from that, but I'd say that the fact that we already didn't blow the planet up along with all complex life on it is a really good prognostic.
@@the300club8 well could be the opposite way, aliens could be even dumber and more self destructive than us.
Idk man, Chogoris is right in that zone. It may not be the most hospitable planet but Jagati faired well there and the Whitescars like it as the home to their Fortress Monastery
I want to mention ideas like "Wang's Carpets" by the author Greg Egan. It is highly possible that any life we discover is entirely unlike any idea of what we have for life on our planet. There are a *lot* of presumptions we make about the nature of life in these discussions.
You've made the most important point in this entire discussion. Carbon-life based bias.
I seriously don't understand how you can call the sun average when it's larger than 90% of stars.
I wouldn't say its larger than 90% of stars, after all we see stars that could have just become giant but to space time and and stuff it only appears small.
I just want to say the discussions in the comments of this video are not only rewarding and educating to read but people are respecting each other.
Not even sure i am on CZcams.