It blows my mind how early we all are. Like if the universe has 10^10^120 years left, it seems like it would be unlikely that you would get here so soon. For that matter, it's just kinda crazy in general that almost at the first available moment, our planet started producing lifeforms. Everything about the Earth screams that it just sort of HAPPENS, but everywhere else we look it doesn't seem like it's well suited for it (so far)
@@friendalex7384 Yes the earth just happens to be the only living planet in the solar system and things just happen to be in harmony with each other. I feel like you're just repeating stuff that sound sophisticated to get people's approval.
I always love this. From like, a philosophical standpoint. Everything you see is in the past... The sunlight on my face is 8 minutes old. When I look at the moon, I am actually seeing the moon from 1 second ago. If I were to find Alpha Centauri with a telescope, I would be looking at Alpha Centauri from 4 years ago. When I am walking to work and I see my friend, I am seeing them from a fraction of a nanosecond ago (or however long it takes for light to move that short distance). Our eyes can only see the past, never the present, and never the future. There's a Vlogbrothers video in here somewhere...
I would also like to add that there is a delay between the light hitting your eye and that signal reaching your brain. So no matter how close you get, you are always living in the past
And if I may add, our brain always waits another couple ns from an upper body sensory signal to sync with signals from the lower body, that take a little more time to reach the brain. This means that taller people live slightly more in the past than their shorter counterparts. Vsauce has a video on the subject if you’re curious
If you think that's trippy, it gets better... The speed of light IS instantaneous. The light from the sun takes 0.000 nanoseconds to reach Earth. But, what we do observe is a shift in causality (the c in the speed of light = 'c'). So, what we do is interpret that relative delay in causality as a functional speed of light. An observed supernova happens at the exact time you see it happen because of a shift in relative time between points in space, not because of a delay.
@@thequantaleaper Oh gods. I thought I was gonna come in here with a trippy brain-breaking fact about how the light has been travelling for 8 minutes but isn't even a second old because a photon doesn't actually experience time from its perspective, but this is way worse - And probably more accurate, from my limited understanding.
My favorite wild fact is that, although the universe is only 13.8 billion years old, we can see galaxies that are 47 billion light years away (due to the Hubble expansion of the universe).
@@JoveRogers97 When Einstein was working out the details of his theory, he needed a way to keep gravity from making the universe collapse back in on itself. To this end, he included a factor that stipulated a constant "pressure" in the universe that acted as a kind of anti-gravity. He eventually scrapped the idea, calling it his greatest blunder. Decades later, Mr Hubble discovered that the universe was expanding, and after calculating how fast this expansion was, it was found to match the factor that Einstein had chosen to discard. Einstein was the first to suggest the Cosmological Constant, even calculating it's value, which was later confirmed by Hubble. It is now called Hubble's Constant or simply the Cosmological Constant, and less frequently Einstein's Constant. I just think it would be fun if cosmologists called it Blunder Expansion
I doubt you’re old based solely off of your profile pic I’ve never seen an old head have one of those cringe chibi character things that look like they were drawn by every middle school emo kid ever
There was a mathematician, Paul Erdős, who would say he was about a 3 billion years old. When he was born, the estimate age of the universe was around a billion years. In his later years, the new estimate was around 4 billion.
@@ethanfreeman1106 Erdos is making a joke when he was born, the estimated age of the universe was 1 billion years old, later we did more math and (within his lifetime) changed the estimate to 4 billion years. therefore, he claims he is 3 billion years old since the estimate was 1 billion when he was younger and went up by 3 billion to 4 billion years let me know if that helps 😃
I don’t think you have the numbers right. by 1920 we knew the universe was at least 2 billion years old, because by that point consensus was reached in the scientific community that the earth was between 2-4 billion years old at that point
@@bradonhoover3002 yup, 1913 to be exact. By the time he was old enough to have even heard people talk about the age of the universe it would have already had an estimated 5-10 billion year lifespan
I just had to explain this concept to my son the other day... when telescopes see a planet that is 10 million light years away we aren't seeing the planet as it is today BUT how it looked 10 million years ago because that's how long it takes the light to get to us!!! that's a mind boggling fact that he was trying to grasp!
It's even more mind-boggling to realise that a whole civilization (or more) may have begun AFTER the light left that star, and ceased to exist BEFORE the light reached us.
@@bwood6337 It's not just you that feels that way. One estimate of the amount of time the universe can produce new stars is through 100 trillion years. That number also doesn't *sound* all that big to me, but the current age of the universe divided by 100 trillion is about 0.00014 -- we exist at a TREMENDOUSLY early time in the lifetime of the universe!
Is it possible that sentient civilization with telescopes that may arise in the future would find themselves in a universe so old they won't be able to notice any cosmic background radiation? And would not be able to determine how old the universe is?
The background radiation will always be there, but the density of radiation per unit of space will continue to get lower and lower, meaning we'll need more and more sensitive instruments to detect it, and there's theoretically a time when the density will be so low it'd be impossible to build a system sensitive enough to detect the radiation, but this is a LONG LONG LONG LONG LONG LONG LONG time in the future. And at that point, every galaxy might be so far away from each other that any living civilization might not even consider the possibility that universe is expanding. We only thought to check because we noticed there were other galaxies moving away from us, and the very far away times might not even see another galaxy to know it's moving. So they might think the universe is simply empty darkness that goes on forever, never changing.
@@misteryA555 That is virtually guaranteed, so long as there is any intelligent life at that point in the life of the universe. There will come a time when intelligent life will never know anything outside of their own galaxies, no matter how good their technology. The observable universe, set by the cosmological horizon, will effectively shrink. Of course, for a period of human history, when we figured out we were floating in space among a group of stars, we didn't know that some smudges of gas we had seen by telescope were other, incredibly distant bunches of stars as well.
Absolutely yes. Our current understanding is that the universe will continue to expand until no light of any kind will reach us (anywhere) from the distant past. When no light of any kind is detectable, and including gravitational waves that also travel at the finite speed of light, there will be no way to even postulate that the universe is anything other than a vast empty ever-present void. This is a more interesting time to exist.
I think I read somewhere (Stack Exchange maybe?) that when they can no longer see the cosmic microwave background radiation, they would need to observe hypervelocity stars to be able to determine an estimate for the age of the universe. I think it would be a lot less precise, but the age would be in trillions of years then, so the precision we have wouldn't matter as much to them.
Since you brought up microwave background radiation, I remember hearing years ago that CRT TV static is caused by the presence of that radiation while the TV isn't actively displaying something.
CRT static is caused by electromagnetic noise in the signal. Some of it is CMB, but also it comes from every other source that emits electromagnetic radiation, from the sun, to the spark plugs in your car.
@@davidcolera8160we just got one! It's from a secondhand and my mom bought it because it was cheaper and would last longer than our previous new models
Hank, give me a book recommendation for soil. As cannabis is closing in on being legal to grow in my state this summer I've been studying and researching. Soil is quite fascinating, as you put it in one of your videos before "all of the known life is on a very very thin part of the earth" the soil underneath giving us the chance to thrive
Cannabis and tomato plants like fairly similar conditions, including soil and fertilizer and is usually much easier to find info on tomatoes and the soil they like than it is for cannabis so might be worth searching for that 😊
I'm almost 33. If I multiply my age by 418181818, I roughly get 13.8 billion, which is the amount of years scientists think have passed since the big bang (with a 1% margin of uncertainty). Therefore, the universe is as old as 418181818 of my lifetimes.
And considering that what we understand as time came to be with (or after?) Big Bang, this is actually how old the universe is, measured in units of what we understand as time. Because _"before_ the Big Bang" doesn't have the same meaning as we understand 'before' within space-time, with causes and effects (although in Minute Physics they call both "levers", physics is weird),, neither does the "space" that could've existed "before" spaciousness as we know it existed. So, even if the universe "was" in some other states "before" the Big Bang we have no language for it, we have no physics for it and we have no idea where to get the data from. So, this is indeed roughly how old the Universe - as we know it - is.
I think that aligns with the theory I've always had of "things probably existed before the big bang." To preface, I don't have a solid grasp on the current idealogy of physicists and whatnot. But I feel like our big bang might have been just a huge cosmic event (from our perspective at least) in a period of low activity. If that's the case, there could be many (or (somewhat) infinite?) big bangs far away and at different points in time. That would mean the "actual universe" would be much larger and older than we talk about (and likely part of a bigger whole?), just exponentially out of our range of perception.
@@joecosta3416 Considering what we have learned so far, the real answers are more likely to be less fantastic than we think, but more infuriatingly weird, than we can ever imagine. That's just a guess, of course. But I get your interest to _know_
Even the physicists can't agree on this. It's probably always going to be just a theory, as it's really difficult to get evidence of an "event" that happened billions of years ago that left evidence that is open to interpretation.
Nothingness is something incredibly hard to understand haha it has to exist because we can't have something without nothing light without dark... But its not there so u can't think about it 😂
I just want to say i love your content you inspire and fuel my love for science also you look like the blonde kid from meet the robinsons which is cool
Follow up question. How do we know the distance of those far away things to calculate how long it took the light to travel from them? I'm sure I can look it up but I love the way you explain things in easy to understand terms.
It’s a lot to do with a concept called redshift. Pucrure this: the sun is currently emitting light, and this light is formed at a certain wavelength and we know what wavelength we’re supposed to be seeing, right? So because waves have a certain frequency that correlates to a specific length between the peaks, We can determine about how long the wavelengths coming from objects should be. Here’s where shit gets a little heavy. So the universe is expanding faster than the speed of light meaning that over time, that wavelength is slowly getting stretched because a wave can only travel at light speed, but if it is traveling through a medium that is growing, then it is constantly being expanded as well. This is the concept, known as red shift. so because of this expansion of the wavelength of the light emitted by the object that we are trying to determine the distance of, knowing the speed of the expansion, which we know to a relatively precise degree, with what we call Hubble’s constant, we can do a little bit of math to take that red shifted light and determine its original wavelength, therefore, finding the red shift, and finding the value of its distance.
The deniers would say "I can't do the math, therfore it doesn't exist " spoke to one guy who said "carbon halflife doesn't go back 4 billion years. Therefore the earth can't be that old" he couldn't comprehend that carbon dating is an umbrella term for radioactive dating.
His point might be, why isn't all the radioactive carbon used up on Earth? It would all decay away within several thousand years after it's created. To which the answer is that radioactive carbon is constantly being manufactured by the interaction of cosmic rays in our atmosphere.
No, carbon dating is not a generic term. It’s when the Carbon-14 concentrations in organic matter is used to date objects. It can only be done with organically occuring materials like wood, bones (not fossils$, hair, etc. though.
@jownadel1526 well I know it's not been entirely accepted yet, but I was curious about how they found the universe may actually be 26.7 billion years old. I was under the assumption they used a "tired" light theory to calculate it.
@@brandonbuzzell8731 having just read the article about the theory that you were talking about, I think that it’s kind of absurd to assume that not only does light lose energy after so long, yet is still detectable, after literally traveling for as long as the universe has existed, and not showing any other signs that we have been able to detect so far of becoming “tired” (which btw, wouldn’t make a lot of sense due to the fact that light is massless, and photons are a discrete quanta of energy that don’t interact with things the same way as other EM radiation) and not only that, but also by saying that our cosmological constants are actually not constant and have evolved over time This man is basically suggesting that a ton of the information that we know is wrong, and to fit in these discrepancies of the early universe (while creating completely new ones en masse) else in physics will have to be revised because of this.
What's super cool is that there's a ton of techniques depending on how far away things are. Stars are usually measured by parallax, REALLY far away stuff from red shift and kinda intermediate distances (such as they are) use a bit of motion measurement as well as red shift. It's crazy that there's so many ways to do it.
It baffles me how much data astrophysicists can deduce and extrapolate from roughly a single photon detected. Like if you've seen those papers you'd find at the top sometimes a single measurement : At X time there was X dot with brightness X. THEREFORE, a full page describing the solar system of the star and the planets orbiting it and the composition of their atmosphere and the size and speed and distance and ...
@@breezyashell We theorize that the universe is expanding, thus causing farther things away to be more red. They're more red because over the long trip to us the wavelength gets extended.
We can also look at certain distant types of stars (super nova) and estimate their distance by how dim they appear (oversimplified). The age estimated by that method roughly agrees with the age estimated by measuring redshifts and by estimates based on the cosmic background radiation. It gives us high confidence that all those different methods agree. But if you try to get too accurate, they disagree and that's what is flippantly called the crisis in cosmology, which just means that some of those methods are not yet completely accurate.
Hey Hank, for many years you and John have been very good at making me feel better about life. So I'm now I'm an adult, but I just had the worst thing to ever happen to me and I'm really hoping you can be the 'distant object producing light' that I need right now.
i am neither of the green brothers, but i'm sending you well-wishes from afar. and love in the "you're another human suffering and i care about you" kind of way. i believe you can get through this, and whatever you're going through i am so, so sorry.
I have a question for Hank: is a fork or spoon more efficient for mixing? I wonder because I think forks would create more turbulence, but spoons move a greater volume.
It could still be that way now. Remember that at one time, we KNEW the earth was flat and we KNEW that the earth was the centre of the universe. There is still lots of stuff we don't fully know and understand, so what we know now, is based upon our understanding at this time. We could be wrong.
Do we know if the speed of light has always been consistent? Could it have moved faster or slower at any given time? If so couldn't that possibly change age?
Light has never been observed to change speed in a void under regular gravitational circumstances, so there’s no reason to assume it would. Especially for no reason.
I always appreciate Hank using 'we'. I know hes talking about us as a species but I don't know anything about time and space and I feel special just being included
*When I want to see history as it’s happening I stargaze ✨👁️👄👁️✨* *_“We are all in the gutter, but some of us are looking at the stars”_** - Lord Darlington📖💫*
I took a cosmology class and we spent like a month going over the different iterations of the equation that led to our understanding of the age and expansion rate. The prof considered it pretty important that we understand that he and his colleagues worked really damn hard to figure this out for us.
I do love that I'm living in a time where we can know this stuff. I really love learning, so it would be a difficult time for me not to have access to all of this information. However, I'd probably be more specialized in a few things if I wasn't so distracted with new information too...😂
All the space oddities aside,... I really want a video of you playing that guitar! Lol I know you said you can't pull off singing a song with your mustache lol but I beg to differ.
I think there’s an issue here. The light we weren’t detecting has redshifted and that lack of information led to the 13.8 billion number. Now with JWST we can detect that light and much older light which is challenging that number, right? I doubt I explained or understood that properly, but I’m pretty sure I read that somewhere. If someone has better info on this, I’d love to see a better explanation.
Not challenging the number at all. We can just see "further back" now, because JW has more sensitive longer wavelength detectors. It's just better at seeing "darker" (for lack of a better word) objects. In particular, it can detect IR radiation (as well as microwaves) which are much fainter. The focusing mirror is also much bigger, so more light (etc) comes into the telescope to begin with, in addition to having much more sensitive detectors. We are just seeing objects which are much further away than we could before, theyre not exactly suddenly billions of years older than theyre supposed to be.
@@iami3rian394 I’m not saying that the things we are already seeing have suddenly aged or are somehow older than we previously thought. We are, however, seeing galaxies that are older than we thought galaxies could be. The possible implications here are that the universe *might* be older than we thought. Some of these old galaxies are thought to have formed after only 250 million years; this is much earlier than when we previously thought they could form at all and that’s the potential challenge to the 13 billion number. I’ve been following JWST for about 8 years now; not as long as a lot of others here, but still long enough to understand the difference in hardware between Webb and say, Hubble. I understand that the big mirrors are able to capture more light and focus them into the secondary mirror and so on. Larger mirrors allows for more sensitive light detection, thus allowing us to see further into the past. I’m a layperson here, but I think I get the gist.
@@sspearss9112 galaxy formation earlier than expected is incredibly interesting, but in no way a threat to the big bang. They are still exclusively first generation stars, small galaxies, and aside from the discrepancy in WHEN they came about there's nothing out of the ordinary about them. The rate of expansion is constant. It's simply not possible for the big bang to have occurred at any other point. When you rewind the expansion, you are invariably left with one particular moment where everything existed at a single point. That moment can't just be bumped back a few billion (etc) more years without changing the rate of expansion. It's just not possible.
@@sspearss9112 you're welcome. It's VERY true that the galaxy formation is bizarre. One hypothesis is that they're very rare because at this point there shouldn't be any super massive black holes yet. Currently, we don't know if we're wrong about when they formed, or if we're wrong about needing super massive black holes to form galaxies to begin with. Unfortunately, it's likely that the webb isn't big enough to solve that particular issue, just yet. So, it's back to math, while we wait for an even larger telescope to get funded and launched. 😁
You should do a video talking about how we recently discovered that the rate of the universe’s expansion is not actually increasing but actually it may be decreasing.
An interesting rough estimate is that all humans alive right now make up about 6.5% of the total population of all humans to have ever lived. Being alive while our species knows the rough age of the universe is a little unusual, but for a human to have red hair is way more unusual.
One day they gonna say "we're pretty lucky to be born in the age where human can utilize the full extent of the planet energy" hope this day will come soon 🙏
Brian Cox said in an interview that “the universe was too hot to create atoms” but I always thought that heat was created by atoms moving? How can an atomless space be hot?
You're right that heat is the movement of atoms, but that can be caused by other sources of energy besides heat. For example, when you stand near a blazing fire and feel it's warmth, it's not that the air touching your skin has suddenly become very hot, but the infra red light from the fire (photons) is passing energy into your body, which becomes heat. That's why your back will stay cold too, the light doesn't go behind you. So, the univers was probably disorganized subatomic particles and pure light at that point!
Actually, not "pure" visible light, it could have been more energetic wavelengths that would have been invisible to us... it's crazy that it could have actually been "dark" in the visible spectrum.
It is worth noting that when the CMB fades to nothing and the expansion of space makes it so we can no longer see the origin of the universe, it will become impossible to prove that a Big Bang occurred or what age the universe is. The evidence that allows us to know these things has a limited shelf life.
Not really. It will take forever to it to “fade away entirely”. It will diminish in density, but never truly fade away. And by that “forever” when the density is too low to feasibly measure, so much time will pass that it won’t matter (and there will probably exist more advanced species that figured it out by other means, akin of traveling to the source etc).
when someone says ‘don’t focus on the past! keep looking forward!’ but the laws of the universe won’t let you. i’m trying, susan, BUT I CAN’T BEAT THE SPEED OF LIGHT
Correction the observable universe. It is entirely possible that there are galaxies out there Beyond observation. There might not be but there could be which is why we use the term observable universe.
Its super interesting the fact that light can technically time travel, science is complicated and weird sometimes, but wow that thing is incredibly interesting too
General relativity is wack. The whole idea that space and time are relative and objects experience the flow of time more rapidly as they accelerate closer to the speed of light, until lightspeed is reached and all of time from start to end is condensed into an instant. But getting an object with mass to the speed of light would require more energy than exists in the universe. It's mind bending
Okay, so small critique, the cosmic microwave background (CMB) radiation effect is technically a leftover from the big bang. However, phrasing it as such makes it sound as if what we see in the CMB is from the big bang itself, rather than what it's actually from which is the recombination event approximately 370,000 years after the big bang.
I'm seeing a lot of questions about how we can tell how old the light is. From what i understand it has to do with redshift. There's the standard redshift that most are familiar with, the light waves produced by objects moving away are stretched out. However, there is another type of redshift. As light passes through expanding space-time, the wavelength is also stretched. By using spectroscopy, we're able to determine the element that produced the light and get a measurement of what the unshifted wavelength should be. Also, supernovae have practically identical composition and radiation, which is often used as a reference that helps establish age and distance based on redshift. I think that's about it though. I hope hank finds the concept of an expanding space-time causing redshift as fascinating as I do. :D
Question- if before the big bang, all matter was in a singular point the way school taught me, wouldn't that just become a massive black hole? And how would that ever, yknow, go bang?
@@castleanthrax1833 this exactly. we don't know how, we only know that it did. (based on the evidence we've got, the theory of course being eternally subject to change)
This gives some useful perspective on the whole idea that there is something paradoxical about the fact that we have yet to observe any signs of life elsewhere in our universe, given how likely we think it is to arise and how inevitably we have apparently decided the development of radio technology will follow. Even if there are other creatures that have been beaming out signals, we won't know about it until long after the fact, and we have no idea how truly lucky we are in terms of our developing relatively early in the universe's lifespan. The universe may already be a pretty noisy place, with many different sources reaching the same level of development around a similar timeframe, and our signals just haven't caught up with each other yet. Or perhaps humanity is earlier than we know, and the rest of the universe's advanced civilizations will be developing while receiving our broadcasts long after we are gone... Can you imagine members of some fledgeling civilization toiling away for generations to decipher the meaning behind these cosmic transmissions? I wonder what they will think of us if they succeed...
For some reason, this video made me think about the spinning universe video. And I just realised that if the big bounce is a phenomenon that happen, it would make sense that the universe is rotating, isn't it?
You make it sound so fancy. Take grandmas old TV and tune it inbetween channels. That noise you see on that CRT is actual cosmic microwave background radiation, beeing picked up and amplified by your TVs antenna.
It is quite confuse at the end. The method is simple. We mesure the rate of expansion of the universe, we then then rewind this expansion until the universe get so dense that our law of physics doesn't work anymore. And we chose that moment to be the beginning of the story of the universe (as it marks the beginning of its expansion).
Light has a set speed, so all you need to know is how far away is the thing you're looking at. Example, at the speed of light it takes 8min to reach the earth from the sun. This means when you look at the sun from earth, what you see is how it looked 8 minutes ago. 1 light year is the distance light travels in a year, so something a light year away you will be seeing how it appeared a year ago. To find the distance to an object we do a number of things, for one just like looking at something far away on earth it appears smaller, the same thing happens in space. You can do math on that too calculate a distance. Use other mathematical tools to make sure you calculation is right. Now you input hope far away that is and when you know that, you know how old it is
@@Samantha_yyz Great answer! I'm still struggling to find the original physical characteristic that we can *know*. To get distance from size, we need to know how large it actually is, when we only have the input of how large it appears (affected by distance, which is the unknown we're trying to solve for). I could imagine trying to triangulate the star by the parallax effect, but across astronomical distances, I would think the calculations (on a computer) would break down at some point.
@@snortonmorton Yeah its pretty high level math, Im not too familiar with all the data points they use, so I didnt want to like say oh they do this, cuz well I dont know it well enough to be that precise.
What is CRAZY! Is if Earth and our solar system just lasted forever, and we kept living on it just fine, and our galaxy didn't get eaten by our neighbor (an impossible imaginary scenario I know). Eventually all the other galaxies would drift away beyond our ability to detect, and all we would have is our own galaxy and the lore and myths form our ancestors of realms beyond.
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It still blows my mind how simultaneously old and young the Earth actually is
It blows my mind how early we all are. Like if the universe has 10^10^120 years left, it seems like it would be unlikely that you would get here so soon. For that matter, it's just kinda crazy in general that almost at the first available moment, our planet started producing lifeforms. Everything about the Earth screams that it just sort of HAPPENS, but everywhere else we look it doesn't seem like it's well suited for it (so far)
@@friendalex7384 Yes the earth just happens to be the only living planet in the solar system and things just happen to be in harmony with each other. I feel like you're just repeating stuff that sound sophisticated to get people's approval.
@@wolfgar45 or, they just stated a thought? Like most of us?
I dont remember numbers but it is like 30% age of the universe. It is pretty old
@@JimJakubJames That's the magic number. 3...
I always love this. From like, a philosophical standpoint. Everything you see is in the past... The sunlight on my face is 8 minutes old. When I look at the moon, I am actually seeing the moon from 1 second ago. If I were to find Alpha Centauri with a telescope, I would be looking at Alpha Centauri from 4 years ago. When I am walking to work and I see my friend, I am seeing them from a fraction of a nanosecond ago (or however long it takes for light to move that short distance). Our eyes can only see the past, never the present, and never the future. There's a Vlogbrothers video in here somewhere...
I would also like to add that there is a delay between the light hitting your eye and that signal reaching your brain. So no matter how close you get, you are always living in the past
And if I may add, our brain always waits another couple ns from an upper body sensory signal to sync with signals from the lower body, that take a little more time to reach the brain. This means that taller people live slightly more in the past than their shorter counterparts. Vsauce has a video on the subject if you’re curious
If you think that's trippy, it gets better...
The speed of light IS instantaneous. The light from the sun takes 0.000 nanoseconds to reach Earth. But, what we do observe is a shift in causality (the c in the speed of light = 'c'). So, what we do is interpret that relative delay in causality as a functional speed of light.
An observed supernova happens at the exact time you see it happen because of a shift in relative time between points in space, not because of a delay.
But like...thats just the liberal universities making shit UP bRo. /s
@@thequantaleaper Oh gods. I thought I was gonna come in here with a trippy brain-breaking fact about how the light has been travelling for 8 minutes but isn't even a second old because a photon doesn't actually experience time from its perspective, but this is way worse - And probably more accurate, from my limited understanding.
My favorite wild fact is that, although the universe is only 13.8 billion years old, we can see galaxies that are 47 billion light years away (due to the Hubble expansion of the universe).
As cool as Hubble's work was, I still think it would be cooler to call cosmic expansion Blunder Expansion in honor of Einstein's Blunder.
@@randybugger3006 What was Einstein's Blunder?
@@JoveRogers97 When Einstein was working out the details of his theory, he needed a way to keep gravity from making the universe collapse back in on itself. To this end, he included a factor that stipulated a constant "pressure" in the universe that acted as a kind of anti-gravity. He eventually scrapped the idea, calling it his greatest blunder. Decades later, Mr Hubble discovered that the universe was expanding, and after calculating how fast this expansion was, it was found to match the factor that Einstein had chosen to discard. Einstein was the first to suggest the Cosmological Constant, even calculating it's value, which was later confirmed by Hubble. It is now called Hubble's Constant or simply the Cosmological Constant, and less frequently Einstein's Constant. I just think it would be fun if cosmologists called it Blunder Expansion
@@randybugger3006 😂 I'm going to call it that now!
@@JoveRogers97 Considering we use words so everyone knows what you are talking about, that's not wise.
I was going thru my day as an old person, turns out I’m not so old after all. Science is awesome and so is Hank. Thanks Hank!!
your welcome! 😊
We all die young. Even if you make it to 100, that’s not very long really.
.
@@uncoiledfish2561 the goal is to make it over nine thousand
I doubt you’re old based solely off of your profile pic I’ve never seen an old head have one of those cringe chibi character things that look like they were drawn by every middle school emo kid ever
There was a mathematician, Paul Erdős, who would say he was about a 3 billion years old. When he was born, the estimate age of the universe was around a billion years. In his later years, the new estimate was around 4 billion.
I'm so confused by this comment
@@ethanfreeman1106 Erdos is making a joke
when he was born, the estimated age of the universe was 1 billion years old, later we did more math and (within his lifetime) changed the estimate to 4 billion years. therefore, he claims he is 3 billion years old since the estimate was 1 billion when he was younger and went up by 3 billion to 4 billion years
let me know if that helps 😃
I don’t think you have the numbers right. by 1920 we knew the universe was at least 2 billion years old, because by that point consensus was reached in the scientific community that the earth was between 2-4 billion years old at that point
@@ObjectsInMotion he was born in the 1910s
@@bradonhoover3002 yup, 1913 to be exact. By the time he was old enough to have even heard people talk about the age of the universe it would have already had an estimated 5-10 billion year lifespan
I just had to explain this concept to my son the other day... when telescopes see a planet that is 10 million light years away we aren't seeing the planet as it is today BUT how it looked 10 million years ago because that's how long it takes the light to get to us!!! that's a mind boggling fact that he was trying to grasp!
It's even more mind-boggling to realise that a whole civilization (or more) may have begun AFTER the light left that star, and ceased to exist BEFORE the light reached us.
The Sun could pop out of existence and we would be blissfully unaware for 8 minutes or so. Kind of crazy to think about.
Hank, you forgot to tell how old it is, how old is it!
13.787 billion years
@@thegeek3295 Is it weird to say that feels like a surprisingly small number?
Just given that it's, ya'know, the universe.
@@bwood6337 It's not just you that feels that way. One estimate of the amount of time the universe can produce new stars is through 100 trillion years. That number also doesn't *sound* all that big to me, but the current age of the universe divided by 100 trillion is about 0.00014 -- we exist at a TREMENDOUSLY early time in the lifetime of the universe!
@@KyleJMitchell this is why this is one of the potential answers to the Fermi Paradox: we're (one of) the first!
@@bwood6337Billion is a very big number
Is it possible that sentient civilization with telescopes that may arise in the future would find themselves in a universe so old they won't be able to notice any cosmic background radiation? And would not be able to determine how old the universe is?
The background radiation will always be there, but the density of radiation per unit of space will continue to get lower and lower, meaning we'll need more and more sensitive instruments to detect it, and there's theoretically a time when the density will be so low it'd be impossible to build a system sensitive enough to detect the radiation, but this is a LONG LONG LONG LONG LONG LONG LONG time in the future.
And at that point, every galaxy might be so far away from each other that any living civilization might not even consider the possibility that universe is expanding. We only thought to check because we noticed there were other galaxies moving away from us, and the very far away times might not even see another galaxy to know it's moving. So they might think the universe is simply empty darkness that goes on forever, never changing.
@@misteryA555 That is virtually guaranteed, so long as there is any intelligent life at that point in the life of the universe. There will come a time when intelligent life will never know anything outside of their own galaxies, no matter how good their technology. The observable universe, set by the cosmological horizon, will effectively shrink. Of course, for a period of human history, when we figured out we were floating in space among a group of stars, we didn't know that some smudges of gas we had seen by telescope were other, incredibly distant bunches of stars as well.
Absolutely yes. Our current understanding is that the universe will continue to expand until no light of any kind will reach us (anywhere) from the distant past. When no light of any kind is detectable, and including gravitational waves that also travel at the finite speed of light, there will be no way to even postulate that the universe is anything other than a vast empty ever-present void. This is a more interesting time to exist.
I think I read somewhere (Stack Exchange maybe?) that when they can no longer see the cosmic microwave background radiation, they would need to observe hypervelocity stars to be able to determine an estimate for the age of the universe. I think it would be a lot less precise, but the age would be in trillions of years then, so the precision we have wouldn't matter as much to them.
@@CheatOnlyDeath someone needs to write a story where people at this distant future time stumble across a warp/hyperspace capable ship. 😉
When I was a kid, cosmologists disagreed about the age by a factor of 2. Now they've got it to about three significant figures.
I’m always so fascinated by how much we know and how much we’ve yet to learn
The real question is why is always midnight on New Years at Hank's place.
Cosmic Microwave Background is a good band name
Since you brought up microwave background radiation, I remember hearing years ago that CRT TV static is caused by the presence of that radiation while the TV isn't actively displaying something.
Yes except we don't usually see analog TVs anymore :(
We used to call it ant's football. Was cool to watch.
CRT static is caused by electromagnetic noise in the signal. Some of it is CMB, but also it comes from every other source that emits electromagnetic radiation, from the sun, to the spark plugs in your car.
It’s also a (albeit small) part of the reason that you hear static on dead radio stations!
@@davidcolera8160we just got one! It's from a secondhand and my mom bought it because it was cheaper and would last longer than our previous new models
Hank, give me a book recommendation for soil. As cannabis is closing in on being legal to grow in my state this summer I've been studying and researching. Soil is quite fascinating, as you put it in one of your videos before "all of the known life is on a very very thin part of the earth" the soil underneath giving us the chance to thrive
I'm actually curious about this. Even though I don't use cannabis it could help with my mother's plants.
id personally suggest “teaming with microbes” by jeff lowenfels, taught me a lot about growing my own organic up here in Canada :)
Cannabis and tomato plants like fairly similar conditions, including soil and fertilizer and is usually much easier to find info on tomatoes and the soil they like than it is for cannabis so might be worth searching for that 😊
NPK.
I enjoy the chaotic energy of the time counter being on and counting down to nothing lol
Some people think it's only a few thousand years old. Refusal to accept true facts is a sign of insanity. Thank you, Hank!
Which is even crazie4 because we have physical evidence from HUMANS from earlier than that
If you are old enough to have experienced TV static, that is from the cosmic microwave background...
I'm almost 33. If I multiply my age by 418181818, I roughly get 13.8 billion, which is the amount of years scientists think have passed since the big bang (with a 1% margin of uncertainty). Therefore, the universe is as old as 418181818 of my lifetimes.
This guy makes any topic so incredibly interesting! He inspires me to get out of my funk
And considering that what we understand as time came to be with (or after?) Big Bang, this is actually how old the universe is, measured in units of what we understand as time. Because _"before_ the Big Bang" doesn't have the same meaning as we understand 'before' within space-time, with causes and effects (although in Minute Physics they call both "levers", physics is weird),, neither does the "space" that could've existed "before" spaciousness as we know it existed. So, even if the universe "was" in some other states "before" the Big Bang we have no language for it, we have no physics for it and we have no idea where to get the data from.
So, this is indeed roughly how old the Universe - as we know it - is.
I think that aligns with the theory I've always had of "things probably existed before the big bang." To preface, I don't have a solid grasp on the current idealogy of physicists and whatnot. But I feel like our big bang might have been just a huge cosmic event (from our perspective at least) in a period of low activity. If that's the case, there could be many (or (somewhat) infinite?) big bangs far away and at different points in time. That would mean the "actual universe" would be much larger and older than we talk about (and likely part of a bigger whole?), just exponentially out of our range of perception.
@@joecosta3416 Considering what we have learned so far, the real answers are more likely to be less fantastic than we think, but more infuriatingly weird, than we can ever imagine. That's just a guess, of course.
But I get your interest to _know_
Even the physicists can't agree on this. It's probably always going to be just a theory, as it's really difficult to get evidence of an "event" that happened billions of years ago that left evidence that is open to interpretation.
Nothingness is something incredibly hard to understand haha it has to exist because we can't have something without nothing light without dark... But its not there so u can't think about it 😂
@@TheBanana93 Quite annoying, right? 😅
Hank, how are you so loveable. Platonic adoration
Or is it
I just want to say i love your content you inspire and fuel my love for science also you look like the blonde kid from meet the robinsons which is cool
Since he didn't say it, 1958 Allan Sandage came up with the first estimate that is close to what we say it is today.
Young Earth creationists: "NUH-UH!!"
If I assume that *literal magic* is a better explanation than science, then science starts sounding really dumb!
Follow up question. How do we know the distance of those far away things to calculate how long it took the light to travel from them? I'm sure I can look it up but I love the way you explain things in easy to understand terms.
It’s a lot to do with a concept called redshift. Pucrure this: the sun is currently emitting light, and this light is formed at a certain wavelength and we know what wavelength we’re supposed to be seeing, right? So because waves have a certain frequency that correlates to a specific length between the peaks, We can determine about how long the wavelengths coming from objects should be. Here’s where shit gets a little heavy. So the universe is expanding faster than the speed of light meaning that over time, that wavelength is slowly getting stretched because a wave can only travel at light speed, but if it is traveling through a medium that is growing, then it is constantly being expanded as well. This is the concept, known as red shift. so because of this expansion of the wavelength of the light emitted by the object that we are trying to determine the distance of, knowing the speed of the expansion, which we know to a relatively precise degree, with what we call Hubble’s constant, we can do a little bit of math to take that red shifted light and determine its original wavelength, therefore, finding the red shift, and finding the value of its distance.
The deniers would say "I can't do the math, therfore it doesn't exist " spoke to one guy who said "carbon halflife doesn't go back 4 billion years. Therefore the earth can't be that old" he couldn't comprehend that carbon dating is an umbrella term for radioactive dating.
It's not an umbrella term. Maybe the general public confuse it that way? Carbon dating is one form of radiometric dating.
His point might be, why isn't all the radioactive carbon used up on Earth? It would all decay away within several thousand years after it's created.
To which the answer is that radioactive carbon is constantly being manufactured by the interaction of cosmic rays in our atmosphere.
No, carbon dating is not a generic term. It’s when the Carbon-14 concentrations in organic matter is used to date objects. It can only be done with organically occuring materials like wood, bones (not fossils$, hair, etc. though.
Need an updated video on this after the recent discoveries
No. "Recent discoveries" do not contradict with anything in this video
@jownadel1526 well I know it's not been entirely accepted yet, but I was curious about how they found the universe may actually be 26.7 billion years old. I was under the assumption they used a "tired" light theory to calculate it.
@@brandonbuzzell8731 having just read the article about the theory that you were talking about, I think that it’s kind of absurd to assume that not only does light lose energy after so long, yet is still detectable, after literally traveling for as long as the universe has existed, and not showing any other signs that we have been able to detect so far of becoming “tired” (which btw, wouldn’t make a lot of sense due to the fact that light is massless, and photons are a discrete quanta of energy that don’t interact with things the same way as other EM radiation) and not only that, but also by saying that our cosmological constants are actually not constant and have evolved over time This man is basically suggesting that a ton of the information that we know is wrong, and to fit in these discrepancies of the early universe (while creating completely new ones en masse) else in physics will have to be revised because of this.
@brandonbuzzell8731 a theory that had littetaly no basis in anything, it's a thought experiment-
In 100 years they will admit the universe is actually 500T years old.
Still blows my mind how some people think the universe is 6000 yrs old and a long bearded deity created it.
I was born on April 14,2010 Abraham Lincon got assassinated, and the Titanic hit the iceberg on my birthday 👍 good stuff
You must be quite old.
@@castleanthrax1833 I was born in 2010
Fun fact about cosmic background radiation, the static picture on old Crt tvs is cosmic background radiation put into picture form.
Wait really??
Hank apparently has a very different definition of "Simple" than I do 😂
I’m still baffled as to how we can tell how far away deep space objects are
What's super cool is that there's a ton of techniques depending on how far away things are.
Stars are usually measured by parallax, REALLY far away stuff from red shift and kinda intermediate distances (such as they are) use a bit of motion measurement as well as red shift.
It's crazy that there's so many ways to do it.
It baffles me how much data astrophysicists can deduce and extrapolate from roughly a single photon detected.
Like if you've seen those papers you'd find at the top sometimes a single measurement :
At X time there was X dot with brightness X.
THEREFORE, a full page describing the solar system of the star and the planets orbiting it and the composition of their atmosphere and the size and speed and distance and ...
how do we know how far away it is??
Redshift
Redshift meaning that as the stars are traveling away from us the wavelength changes making them look red as they get further and further away
@@snow17048 I'm sorry what. We know how far things are because they're more or less red? I have 10 more questions
@@breezyashell We theorize that the universe is expanding, thus causing farther things away to be more red. They're more red because over the long trip to us the wavelength gets extended.
We can also look at certain distant types of stars (super nova) and estimate their distance by how dim they appear (oversimplified).
The age estimated by that method roughly agrees with the age estimated by measuring redshifts and by estimates based on the cosmic background radiation. It gives us high confidence that all those different methods agree. But if you try to get too accurate, they disagree and that's what is flippantly called the crisis in cosmology, which just means that some of those methods are not yet completely accurate.
my science teacher always gives us videos that ur in to watch!
Hubble's constant is still my favorite calculation in Year 12 Physics class, it's just really satisfying and makes so much sense logically.
Hey Hank, for many years you and John have been very good at making me feel better about life. So I'm now I'm an adult, but I just had the worst thing to ever happen to me and I'm really hoping you can be the 'distant object producing light' that I need right now.
i am neither of the green brothers, but i'm sending you well-wishes from afar. and love in the "you're another human suffering and i care about you" kind of way. i believe you can get through this, and whatever you're going through i am so, so sorry.
That raises FURTHER questions!!
I have a question for Hank: is a fork or spoon more efficient for mixing? I wonder because I think forks would create more turbulence, but spoons move a greater volume.
forks are definitely best for powdery things. like pancake mix or hot chocolate.
Thank you for explaining this! New favorite short on your channel
And standard candles, ya kinda skimmed over that one, Hank :P
A lot of people were probably born in a time when they THOUGHT they knew the age of the universe
It could still be that way now. Remember that at one time, we KNEW the earth was flat and we KNEW that the earth was the centre of the universe. There is still lots of stuff we don't fully know and understand, so what we know now, is based upon our understanding at this time. We could be wrong.
Do we know if the speed of light has always been consistent? Could it have moved faster or slower at any given time? If so couldn't that possibly change age?
Light has never been observed to change speed in a void under regular gravitational circumstances, so there’s no reason to assume it would. Especially for no reason.
Once again, thank you Msgr. Lemaitre!
I always appreciate Hank using 'we'. I know hes talking about us as a species but I don't know anything about time and space and I feel special just being included
You can walk into a building and eat delicacies from all over the world in literally any city. We eat like emperors. What a time.
*When I want to see history as it’s happening I stargaze ✨👁️👄👁️✨*
*_“We are all in the gutter, but some of us are looking at the stars”_** - Lord Darlington📖💫*
I took a cosmology class and we spent like a month going over the different iterations of the equation that led to our understanding of the age and expansion rate. The prof considered it pretty important that we understand that he and his colleagues worked really damn hard to figure this out for us.
I really hope you get
some of the non-slip
nose things so you don't have to keep pushing your glasses back up. ✅
Oh man, if Hank of today heard the news of new galaxies further than what we thought possible
It's amazing to me that I'm alive to witness all this.
Thank you for sciencing with us!
Short explain: light go far for very long, get red, very old
The way Hank's mind work is crazy
it's always fascinating!
I do love that I'm living in a time where we can know this stuff. I really love learning, so it would be a difficult time for me not to have access to all of this information.
However, I'd probably be more specialized in a few things if I wasn't so distracted with new information too...😂
All the space oddities aside,... I really want a video of you playing that guitar! Lol I know you said you can't pull off singing a song with your mustache lol but I beg to differ.
I think there’s an issue here. The light we weren’t detecting has redshifted and that lack of information led to the 13.8 billion number. Now with JWST we can detect that light and much older light which is challenging that number, right? I doubt I explained or understood that properly, but I’m pretty sure I read that somewhere.
If someone has better info on this, I’d love to see a better explanation.
Not challenging the number at all.
We can just see "further back" now, because JW has more sensitive longer wavelength detectors.
It's just better at seeing "darker" (for lack of a better word) objects.
In particular, it can detect IR radiation (as well as microwaves) which are much fainter.
The focusing mirror is also much bigger, so more light (etc) comes into the telescope to begin with, in addition to having much more sensitive detectors. We are just seeing objects which are much further away than we could before, theyre not exactly suddenly billions of years older than theyre supposed to be.
@@iami3rian394 I’m not saying that the things we are already seeing have suddenly aged or are somehow older than we previously thought. We are, however, seeing galaxies that are older than we thought galaxies could be. The possible implications here are that the universe *might* be older than we thought. Some of these old galaxies are thought to have formed after only 250 million years; this is much earlier than when we previously thought they could form at all and that’s the potential challenge to the 13 billion number.
I’ve been following JWST for about 8 years now; not as long as a lot of others here, but still long enough to understand the difference in hardware between Webb and say, Hubble. I understand that the big mirrors are able to capture more light and focus them into the secondary mirror and so on. Larger mirrors allows for more sensitive light detection, thus allowing us to see further into the past. I’m a layperson here, but I think I get the gist.
@@sspearss9112 galaxy formation earlier than expected is incredibly interesting, but in no way a threat to the big bang.
They are still exclusively first generation stars, small galaxies, and aside from the discrepancy in WHEN they came about there's nothing out of the ordinary about them.
The rate of expansion is constant. It's simply not possible for the big bang to have occurred at any other point. When you rewind the expansion, you are invariably left with one particular moment where everything existed at a single point.
That moment can't just be bumped back a few billion (etc) more years without changing the rate of expansion. It's just not possible.
@@iami3rian394 Ah, I see. Thanks, this is kinda what I was wondering initially.
@@sspearss9112 you're welcome.
It's VERY true that the galaxy formation is bizarre. One hypothesis is that they're very rare because at this point there shouldn't be any super massive black holes yet.
Currently, we don't know if we're wrong about when they formed, or if we're wrong about needing super massive black holes to form galaxies to begin with.
Unfortunately, it's likely that the webb isn't big enough to solve that particular issue, just yet. So, it's back to math, while we wait for an even larger telescope to get funded and launched. 😁
You should do a video talking about how we recently discovered that the rate of the universe’s expansion is not actually increasing but actually it may be decreasing.
Hank is located at a place where time doesn't move.
Did that calculation in A Level physics, was cool. Kinda like when you calculate the mass of the milky way and discover types of dark matter/objects
An interesting rough estimate is that all humans alive right now make up about 6.5% of the total population of all humans to have ever lived. Being alive while our species knows the rough age of the universe is a little unusual, but for a human to have red hair is way more unusual.
The more I learn about space and time the more I want to crawl under a rock and be a bug.
One day they gonna say "we're pretty lucky to be born in the age where human can utilize the full extent of the planet energy" hope this day will come soon 🙏
I have found this channel's comment section often reflects the informative, humorous and delightful nature of this channel. Thank you.
Brian Cox said in an interview that “the universe was too hot to create atoms” but I always thought that heat was created by atoms moving? How can an atomless space be hot?
You're right that heat is the movement of atoms, but that can be caused by other sources of energy besides heat. For example, when you stand near a blazing fire and feel it's warmth, it's not that the air touching your skin has suddenly become very hot, but the infra red light from the fire (photons) is passing energy into your body, which becomes heat. That's why your back will stay cold too, the light doesn't go behind you.
So, the univers was probably disorganized subatomic particles and pure light at that point!
Actually, not "pure" visible light, it could have been more energetic wavelengths that would have been invisible to us... it's crazy that it could have actually been "dark" in the visible spectrum.
I would say that it's heat that causes atoms to move, not the other way around.
@@joekeith2819 thank you for explaining! It was really interesting reading your response! 😊
It is worth noting that when the CMB fades to nothing and the expansion of space makes it so we can no longer see the origin of the universe, it will become impossible to prove that a Big Bang occurred or what age the universe is. The evidence that allows us to know these things has a limited shelf life.
Not really. It will take forever to it to “fade away entirely”. It will diminish in density, but never truly fade away.
And by that “forever” when the density is too low to feasibly measure, so much time will pass that it won’t matter (and there will probably exist more advanced species that figured it out by other means, akin of traveling to the source etc).
It will probably be impossible to PROVE a big bang occurred anyway.
@@castleanthrax1833
We currently have multiple independent lines of evidence that show it happened.
when someone says ‘don’t focus on the past! keep looking forward!’ but the laws of the universe won’t let you.
i’m trying, susan, BUT I CAN’T BEAT THE SPEED OF LIGHT
My favourite way to mark time and make people feel old is to tell them how many Jovian moons we knew about when they were born
That's not the age of the universe, though. That's the age of the *observable* universe.
Awe. That’s so cute.
You are saying that from where you can see, that you are the center of the universe.
No?
The UMBR is just the farthest thing we can see and it’s the edge of the observable universe
This... has left me with so many more questions.
Where the hell does Hank live? It's the middle of Summer and yet he's always wearing a parka.
he reverse migrates 😂
The universe is immeasurable and never stops growing
Cool theory
I don't therize l stick to the facts
We may be over-confident about the "we know how fast the universe has been expanding that whole time" bit, though.
Calling the Big Bang, a "Theory" is the quickest way to get beat up in your science class.
Still is a theory along with loads of other stuff. Just a very well proven theory.
No, it really isn’t.
A scientific theory is the best functional explanation for one or more phenomena.
That is brilliant! Amazing!
Correction the observable universe. It is entirely possible that there are galaxies out there Beyond observation. There might not be but there could be which is why we use the term observable universe.
That is amazing! I love science.
Its super interesting the fact that light can technically time travel, science is complicated and weird sometimes, but wow that thing is incredibly interesting too
General relativity is wack. The whole idea that space and time are relative and objects experience the flow of time more rapidly as they accelerate closer to the speed of light, until lightspeed is reached and all of time from start to end is condensed into an instant. But getting an object with mass to the speed of light would require more energy than exists in the universe. It's mind bending
How do you know what knowledge lost civilizations had before us?
I still don’t know 😂 I can not comprehend space and time. Like at all 😅
Okay, so small critique, the cosmic microwave background (CMB) radiation effect is technically a leftover from the big bang. However, phrasing it as such makes it sound as if what we see in the CMB is from the big bang itself, rather than what it's actually from which is the recombination event approximately 370,000 years after the big bang.
Couldn't the cosmic microwave background actually just be even more galaxies that we just can't see because of things like redshift?
I'm seeing a lot of questions about how we can tell how old the light is. From what i understand it has to do with redshift. There's the standard redshift that most are familiar with, the light waves produced by objects moving away are stretched out. However, there is another type of redshift. As light passes through expanding space-time, the wavelength is also stretched. By using spectroscopy, we're able to determine the element that produced the light and get a measurement of what the unshifted wavelength should be. Also, supernovae have practically identical composition and radiation, which is often used as a reference that helps establish age and distance based on redshift.
I think that's about it though. I hope hank finds the concept of an expanding space-time causing redshift as fascinating as I do. :D
Question- if before the big bang, all matter was in a singular point the way school taught me, wouldn't that just become a massive black hole? And how would that ever, yknow, go bang?
You are asking a question that even the smartest physicists are trying to answer. They may never have an answer.
@@castleanthrax1833 this exactly. we don't know how, we only know that it did. (based on the evidence we've got, the theory of course being eternally subject to change)
Damn right I was born at a moment, Hank. Damn Right.
The light got to you in a instant
I can't believe I didn't think of that myself.
This gives some useful perspective on the whole idea that there is something paradoxical about the fact that we have yet to observe any signs of life elsewhere in our universe, given how likely we think it is to arise and how inevitably we have apparently decided the development of radio technology will follow.
Even if there are other creatures that have been beaming out signals, we won't know about it until long after the fact, and we have no idea how truly lucky we are in terms of our developing relatively early in the universe's lifespan. The universe may already be a pretty noisy place, with many different sources reaching the same level of development around a similar timeframe, and our signals just haven't caught up with each other yet. Or perhaps humanity is earlier than we know, and the rest of the universe's advanced civilizations will be developing while receiving our broadcasts long after we are gone...
Can you imagine members of some fledgeling civilization toiling away for generations to decipher the meaning behind these cosmic transmissions? I wonder what they will think of us if they succeed...
For some reason, this video made me think about the spinning universe video. And I just realised that if the big bounce is a phenomenon that happen, it would make sense that the universe is rotating, isn't it?
And new data from the JWST has upended our earlier estimates, and now we think the Universe might be twice as old as we had figured.
You make it sound so fancy. Take grandmas old TV and tune it inbetween channels. That noise you see on that CRT is actual cosmic microwave background radiation, beeing picked up and amplified by your TVs antenna.
Anybody else walking away still not knowing the answer to that question!? lol
It is quite confuse at the end.
The method is simple. We mesure the rate of expansion of the universe, we then then rewind this expansion until the universe get so dense that our law of physics doesn't work anymore. And we chose that moment to be the beginning of the story of the universe (as it marks the beginning of its expansion).
The cosmic microwave in the sky
How do we determine the time the light has been traveling?
Light has a set speed, so all you need to know is how far away is the thing you're looking at.
Example, at the speed of light it takes 8min to reach the earth from the sun. This means when you look at the sun from earth, what you see is how it looked 8 minutes ago.
1 light year is the distance light travels in a year, so something a light year away you will be seeing how it appeared a year ago.
To find the distance to an object we do a number of things, for one just like looking at something far away on earth it appears smaller, the same thing happens in space. You can do math on that too calculate a distance. Use other mathematical tools to make sure you calculation is right. Now you input hope far away that is and when you know that, you know how old it is
@@Samantha_yyz Great answer! I'm still struggling to find the original physical characteristic that we can *know*. To get distance from size, we need to know how large it actually is, when we only have the input of how large it appears (affected by distance, which is the unknown we're trying to solve for).
I could imagine trying to triangulate the star by the parallax effect, but across astronomical distances, I would think the calculations (on a computer) would break down at some point.
@@snortonmorton Yeah its pretty high level math, Im not too familiar with all the data points they use, so I didnt want to like say oh they do this, cuz well I dont know it well enough to be that precise.
Correction: The CMBR is not from the Big Bang, but rather the Last Scattering, which occurred hundreds of thousands of years after the Big Bang?
and now we know how fast to drive a car to shift a red light to green, thanks science!
What is CRAZY! Is if Earth and our solar system just lasted forever, and we kept living on it just fine, and our galaxy didn't get eaten by our neighbor (an impossible imaginary scenario I know). Eventually all the other galaxies would drift away beyond our ability to detect, and all we would have is our own galaxy and the lore and myths form our ancestors of realms beyond.
A world with only the memory of stars. What a haunting image.