LIGO's First Detection of Gravitational Waves!
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- čas přidán 2. 06. 2024
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Today, over 100 years after Einstein proposed his theory of general relativity, we are proud to announce that his final major prediction has been verified! Gravitational waves have officially been detected by LIGO! We are still getting details as the teams of physicists go over the data, but this is a huge deal, and is an exciting new step in understanding our universe.
Have Gravitational Waves Been Discovered?!?
bit.ly/1JKxRXM
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COMMENTS:
TheRealBileth
• Will Mars or Venus Kil...
Laura Lorca
• Will Mars or Venus Kil...
Fabio Brady
• Will Mars or Venus Kil...
Chris Valentine
• Will Mars or Venus Kil...
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FURTHER READING:
NASA's HAVOC Program
go.nasa.gov/1C8VWky
Andy Howell on the science of The Martian
bit.ly/1OtaAs2
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Written and hosted by Matt O’Dowd
Made by Kornhaber Brown (www.kornhaberbrown.com)
Are you sure it wasn't a bird farting in a distant planet?
+cedric robertson See, that might be an even more exciting discovery. Complex life on another planet! Woo!
+cedric robertson .. or maybe a butterfly flapping its wings on a distant planet?
+s8w5 I see what you did there.
+cedric robertson only if it's a bird weighing multiple solar masses who farts neutron star-matter
+cedric robertson I get the reference
I saw these gravitational waves years ago through my LSD telescope, today I feel vindicated.
+Alexi Martinez you dont get it do you?
You must be fun at parties.
A general feeling of the world being suspended in fluid is definitely an aspect of LSD.
Duuude
I like how excited you seem in this video about the discovery. Your honest passion about this subject is really conveyed here, it's great.
Its funny watching this now because everything he said would happen, has happened.
He didn’t predict COVID-19. Ok I give a pass on that,
but what can this do for gaming?
Shorter lags?
I think you are on the wrong channel.
Look for quantum computing channel.
+Dea pond Crazy Machines 3
Half Life 3
+Dea pond :)))))))))))
LIGO seems superficially similar to the Michaelson-Morley experiment.
+Adam Leuer LIGO is actually a Michaelson interferometer (with a few upgrades), so not so superficially related!
PBS Space Time
Awesome, thanks for the info!
+King Lyulf
you had a conjecture/hypothesis ... *not theory* ...
+King Lyulf
you said it yourself ... you were way off ...
for one, space-time doesn't create gravity or dark matter/energy ... and virtual particles don't create space-time ... so yeah ... I had a hard time understanding your statement :)
+King Lyulf What you said is still valid. What LIGO detected was massive amounts of these virtual particles popping in and out of existence that cause gravity in a form of huge waves. For example, lets say water is made of virtual particles, and the water waves are the gravitational waves. Now, I'm just trying to defend your theory / hypothesis but it's still interesting nonetheless. ;)
In the future I will say to my young professionals, "I was alive when this discovery was made"
Hello, I am from 4 years in the future
Wow, the detail of explanation and level of video production is great on this channel!
'Another win for Einstein'... has Einstein ever been wrong?
He was wrong about quantum physics
I think he thought for a while that the universe wasn't expanding.
+Daniel Montenegro Actually his equations told him the universe was expanding but his intuition told him otherwise. So he added a constant to cancel out the expansion. Later called it his biggest blunder.
+David Igboanugo Yes
+Vishal Verma he was wrong about some PARTS in quantum physics
Earth has been so flat lately ! Finally some waves !
:)
+AmbiencePT
If the holographic principle is true then the earth is actually flat.
+dan smith
it was proved that it's not true, though ... just like string "theory", it's a model to help other theories and mathematics along the way ...
+CeaoS What data has proven the holographic principle is not true?
+dan smith Well no, it'd be 2D, in a sense. The holographic principle merely states a the volume of space can be described by its boundary, it doesn't say that boundary has to be flat.
Q&A section at the end of your videos is really awesome.
Great show guys! I don't know how this channel slipped by me for such a long time! You are part of what makes CZcams great!
Wow you got that out fast.
thats what she said..?
+Jared Tami Yep that's what she said
+AFastidiousCuber The video was prerecorded in January.
+Jared Tami wow awesome respond
This could be the way advanced civilizations communicate...
It would be stupidly inefficient as radio waves travel at the exact same speed.
Anthony Khodanian but they reach huge distances. Not for a quick chat but it could be a good way to let others know you were here.
+Bullet Bill Other civilizations would develop the warp drive faster than us.
+Bullet Bill "Not for a quick chat"
Imagine the amount of energy needed to send even a few binary bits of information by manipulating movement of entire stars systems. With so much energy at you disposal, it will be cheaper to communicate using neutrino bursts.
+Bullet Bill The range is absolutely irrelevant when it doesn't travel fast enough to be reliable communication. The range may be 5 billion light years but that means it takes 5 billion years for light to travel across it, 5 billion years for somebody to get their text message. You would need to create a wormhole between the two places to have reliable communication, anything less makes communication impossible.
Modern science is so amazing.
Keep on the great work guys. Much love.
Does every object moving through space generate a gravitational wave? If so it should lose the kinetic energy, right? And if so, then given enough time it should slow down to 0 relative to the space itself. Wouldn't it contradict Special Relativity?
Great question man. But do they carry energy???
+mosaab debiat ofc..waves carry energy
+Michał Gawron I second this, fantastic question!
+Michał Gawron I think there have to be 2 objects moving in each others fields to create a wave. So it's still relative to other objects and not to the universe itself. But I hope someone will explain better. I'm not an astrophysicist. I know nothing about the universe (that's why I watch these videos).
+Michał Gawron A quick (probably wrong!) calculation: Flapping my arms up and down would produce a loss of energy of about 10^-40 Watts between me and the Earth.
This one is known though: The Sun and Earth system loses about 200 Joules of energy per second, which would result in their collision in about 10,000 billion times longer than the age of the universe.
All I can say is YES!!! This is very exciting, and I didn't know about ELISA at all until this news broke, so that's interesting.
QUESTION: Do A-LIGO's two locations allow it to determine a direction from which the signal was detected? Can we point to a region of known universe and say "Yes, the black holes merged that-a-way!" ?
+dequinox In PBS Space Time's previous video on g-waves he mentions the purpose of having two of them to be making sure that they aren't recording a local seismic event or something that would only show up at one facility.
+Efraim Scarf Yes I do remember that. My question wasn't about that.
+dequinox Yes, but you´ll need at least 3 Detectors, which are ideally far away from each other. Then you can basically triangulate the same way GPS works. This is also one reason why ELISA is so exciting, because their three detectors a million kilometers apart. But with the Virgo detector in Italy, coming in July this year, it will be already possible to give a precise Direction where the waves will be coming from.
Yay
+John Titor Indeed, after going to back to watch the initial gravitational waves video he does mention that you can get a rough direction by measuring the relative path lengths.
Congrats on getting this video out so quickly
I was so excited to hear this yesterday morning!
".1% of the observable universe..."
Okay, the universe is really really big, but galaxies are *also* really big, so .1% would probably be something like a couple dozen ga-
"that's millions of galaxies!"
*JESUS*
lmao :)
Yeah, the size of the universe is incomprehensible. All you can really do is memorize large numbers and quote them when necessary.
On the other hand, a single cell in your body contains millions of atoms, and there are about 40 trillion cells in your body, so basically the extreme scales of the universe are incomprehensible in both directions. We are perhaps fortunate that the size of our bodies is approximately in the middle of the insane range of scales that exist in the universe.
@J Thorsson: You had nine months to come up with a zinger and that's the best you could do? I award you no points, and may God have mercy on your soul.
@J Thorsson: Ah. Now that I go back and read my reply to that other comment, I'm actually flattered that you understood the joke I made. :)
Moving to the country. Thank you. Not that anyone cares. Patinga.
Obviously, this was recorded before the discovery was announced, as you wouldn't otherwise have had enough time to create this video within the few minutes since the announcement was made.
+pr0N00bie Yes - rumours have been flying since Krauss tweeted back in ... December?
+Physics Videos by Eugene Khutoryansky whats the point lol its an informative video
Nice job in stating the obvious :3
+Physics Videos by Eugene Khutoryansky Yea thats what I thought too, I think they knew they were going to observe them one day or an other so they just pre-recorded the video. But thats a great discovery and I'm super excited !
+Physics Videos by Eugene Khutoryansky No shit?
3:28 The Classical Explosion!! And his serious talk, I'm rolling on the floor lol
I'm not a physisist, I don't know exactly what you are saying, but it sounds AWESOME!! I subbed! Cheers, Gerardo - London
What happens with the energy carried by the gravitational wave?
Will it forever stay trapped as gravitational wave or does it transform in other types of energy?
Presumably the energy slowly dissipates as heat as it interacts with matter, because the gravitational waves flex the atomic bonds holding molecules together, and the subatomic bonds holding atoms together. Maybe occasionally the energy is just enough to make a fissile atom break apart sooner than it otherwise would've, or just enough to strip an electron off an atom that was already on the verge of being ionized anyway. But the thing you have to remember about gravitational waves is, no matter how big they are, they are still stupendously weak compared to other forces we are familiar with. Gravity is 10^24 times weaker than electromagnetism. Need proof? Put a small piece of iron or steel on the floor -- some paper clips or a strip of staples will work nicely. Then pick it up using a magnet from your fridge. Congratulations! Your fridge magnet just overpowered the gravity of the heaviest solid object in the entire solar system.
i have a question: Why do gravity waves travel at the speed of light ? it's not "matter" in order to be limited by it.
and Can we possibly someday use mini *black* *holes* to generate the near infinite energy to fuel a warp drive? Steven Hawking suggested the use of mini *black* *holes* to generate energy... If we managed to create one
Thank you! Simply just thank you for this incredible show!
On the mars storms questions.. pressure is not what it matters to know what force the wind can exert.
What it matters is the density of the air (which is no so low as the pressure and you still need to add the dust that the storm rise), gravity of mars and soil friction (this is the counter force that an astronaut can make to not fall) and the reynold number (which stay laminar at high velocity increasing the friction).
If you put all those things together with winds of 350kmh, is enough to make an astronaut fly (I already did the math)
This is because wind force increase with V^2, which make it a biggest factor than air density.
So this may be a stupid question, but if gravitational waves are in fact "waves" does that mean sets of GWs can combine or cancel like regular waves?
Yes. But the likelihood of two sets of gravitational waves generated at different points in the universe being the same amplitude *and* being perfectly out-of-phase at the moment they both reach Earth is very nearly zero, so it's equally unlikely for an interference effect to mess-up LIGO's readings.
I literally was so happy to see them finally gravitational waves, WE LOVE YOU ALBERT EINSTEIN!!!!!❤️😱
This is an absolute amazing breakthrough!
Excited to see this announcement! BTW at 7:01 I'm pretty sure you mean that it's hard to OVERstate it. If it was hard to understate it, then it would be not a big deal at all. :)
I HAVE A QUESTION: When black holes merge, do they merge like soap-bubbles, popping together as soon as their event horizons touch, or do their centers-of-mass have to touch for the merge to complete?
Of course we won't ever see the singularities merge. (It's not possible to see below the horizon.) What really happens is that the two black holes get closer, the shape of the two horizons deforms, and eventually a single horizon forms covering both black holes. (You can find an animation of a black hole collision on CZcams.)
@@MikeRosoftJH: I know we will never see the singularities merge -- and indeed, they may never merge since they have zero size and can continue inspiralling forever without touching each other, provided the laws of physics in the space adjacent to singularities allow for such things to occur. But I'm still curious as to whether the event horizons simply overlap with each other as the singularities spiral inwards, or whether the event horizons merge into a single smooth surface the instant they touch. I ask because it can be argued that the event horizons are the only "real" parts of the two black holes since they are they only parts that ever interact with the rest of the universe after the singularity forms. So maybe the event horizons "pop" together like bubbles when they touch, while the singularities themselves are merely mathematical abstractions. That seems like a possibility, anyway.
@@deusexaethera As I have said: the black hole horizons certainly won't overlap like two shadow images. What really happens as the black holes get closer is that the horizons will deform, and eventually, as the black holes get sufficiently close to each other, a single horizon will form covering both of them. (Again: look up an animation of a black hole merger.)
@@MikeRosoftJH: I suppose that makes sense. Still, I have to wonder if the singularities are even "real" in the first place. Black holes are real, but that doesn't mean they contain mathematically-impossible nuggets of infinite density in the center. I suppose we'll never know for sure.
Would we be able to detect interference patterns when the waves collide?
This guy is really refreshingly awesome. I'm ddicted to this channel. Thanks!!!!!!!
Nice! Grats to the A-LIGO team for not only detecting one, but resisting the urge to jump to any conclusions before the hard work was done. That is a team who is doing it right.
The gravitational waves video link in the description is broken. Here is the correct one: czcams.com/video/1Tstyqz2g7o/video.html
+Penny Lane CZcams seems to be having trouble linking to other videos in the description recently. The annotations in-video should still be working. Thanks!
PBS Space Time Great, more CZcams bugs ... I was getting used to the one we already had so I'm glad they're keeping us on our toes.
How can black holes merge if anything that falls into a black hole appears to be frozen near the event horizon?
+Daniel Skiba Black holes are huge gravitational disturbances in space-time, not matter, so they can merge into one.
+Tony Wells this is not true, their exact working are unclear, however they are formed from neutron stars and have in fact matter inside in some form, possibly pure enrgy form. as i said, their inner workings are unclear
Eugene InLaw General relativity describes them pretty well.
+Daniel Skiba If you want to be really technical they *don't* appear to merge, they just get really, really close to doing so. Really close. And this is the case as long as you stay far away and don't approach the pair to see what's happened.
+Tony Wells
Not really. Black holes end up in a singularity (at least mathematically not physically), at that size quantum effects become dominating, but GRT is not a quantified, but a classical theory and therefore can't really describe a black hole in full detail. For that we need a theory of quantum gravity which currently does not exist.
The GRT description of black holes is therefore an insufficient description and surely not the real deal. To what degree a quantum gravity description would differ from that of classical GRT is unknown. So honestly: nobody truly knows right now.
Another awesome video. Cheers!
I think you should make mini tests about info you give in videos, so people can make sure they understood everything in the video. You could just link them in description or something. That would be very cool.
just think about it
just 100 years ago we still had tsars and empires
and 400 years ago were dark ages with religion rulong over people
and today, we are observing ripples is fabric of space itself
long live science!
+Eugene InLaw Uhhhh....
Don't google 'Iran' or 'North Korea' or 'Russia', preserve your innocence.
+Eugene InLaw
Russia still has a czar and acts like an empire.
And I'd guess that the thinking and behavior of 70 percent of all people on this planet is still primarily dominated by religion instead of science, even if the own a smart phone. Also 90% are more or less scientific illiterates who can't distinguish the schroedringer equation from Newtons second law.
So not much has changed. Technology changed, humans didn't
Gareth Dean russia is in war agains my country dude, i know perfectly well everything that goes around the world
as scepies we are as savage as ever, but science has advanced dramatically since religion's rule has been abolished. russia is a prime example of how religion is lethat to human intellect
Eugene InLaw
That and the decidedly atheist communism. I just hope when science takes over our deaths will be painless.
LevittownPaIsSpecial
Giordano Bruno .. burned at the stake for heresy ...(roughly 50 years after the Galileo incident) and these are only the famous examples ...
Corrected link to NASA's HAVOC: sacd.larc.nasa.gov/branches/space-mission-analysis-branch-smab/smab-projects/havoc/
+ignalb Thanks. Updated!
nice vid keep up the good work!
I saw Rainer Weiss from LIGO give a talk at McGill University a couple of months ago. A truly exciting talk about a wonderful result.
With these gravitational waves, is it possible for there to be a negative gravity at the top of those waves?
No. It is simply a smaller positive value.
So do gravitation waves travel at the speed of light?
+Zendail Yes they do.
+Zendail The theory predicted that they would travel at the speed of light, and this was confirmed by this experiment as well.
+johnie102 But do they slow down in matter, just as light does?
*****
It seems like it does, but actualy doesn't. I know. Destructive wave interfearence from matter generated wave and primary wave.
*****
Can you tell me what you mean by that it doesn't. Cause I think you don't know what you're talking about.
Mat's excitement and happiness was in his face!
I literally cheered at the TV when I saw this on the news this morning!
Unbelievable achievement. Very honored to have had all three LIGO winners on our podcast.
I got an question : Could the lack of oil in the future crush our ticket to space ?? Can you fly a rocket with any fossile fuel ??
btw
greetings from germany love your show :)
Ein Hauch von Tüll [RU] many rockets use a mix of propellant including RP-1 which is highly refined kerosene but there are plenty of other propellants that are used, not sure how sustainable they are though.
en.wikipedia.org/wiki/Rocket_propellant#Current_types
There are methane rockets that are looking quite promising, also the 'sky hook' or space elevator is a concept that has been around in scientific fantasy novels for decades. It was even featured as a plot item in a Star Wars video game "The Force Unleashed" involving the Wookiee species being enslaved by the Empire. starwars.fandom.com/wiki/Skyhook/Legends
Rockets can burn any combustible gas. For example, rocket engines are often ignited using tri-ethyl-borane, which spontaneously combusts when exposed to oxygen. (the exhaust is toxic, so they don't use it for the primary fuel, but it _could_ be used as a primary fuel in an emergency.) Also, methane is not a fossil fuel. I know we get most of our methane from fossil sources right now, but the earth does actually produce enough fresh methane to meet our needs -- we're just too lazy to harvest most of it.
Congrats on finding another!!
I'm so glad I was alive to see this.
I wonder if somebody else in the universe was watching the same event.
Hopefully.
Correct me if I'm wrong pls. But didn't gravity probe b pick this up ???
+gcirc Gravity Probe B measured the spacetime curvature caused by the Earth's mass (via the geodetic effect) and the dragging of spacetime due to the Earth's rotation (frame dragging). These effects are different to gravitational waves.
+PBS Space Time thanks for the reply. I'm self taught so I get don't always get things correct. It's kind of a hobby of mine learning about anything science. Your videos are great and help a lot keep up the great work. 👍🏾
It would be very difficult to overstate the importance of this discovery! It is obvious that LIGO, due to its geometry, detected the 3-D spacial portion of the gravitational waves. However, these waves are 4-D, with time being the 4th. dimension. Do the LIGO detector(s) also have the capability to detect the temporal effects of the passing gravitational waves? My heartiest congratulations to the LIGO team. I see a Nobel Prize in their futures!
A "body" that has mass curves the spacetime "inwards", and time passes slowly at the center of the curve than at the outer portion of the curve.
If we look at the gravitational waves it consists of Crests and troughs. Troughs is the portion where the spacetime is curved inwards and Crest is where the spacetime is curved upwards. Can we assume that the crust of GW is anti-gravity field, i.e., the time flow faster at the center of the curve than at the rest of the curve.
Can you surf on them?
So what would you feel, on a human scale, if you were close to a pair of merging black holes as they coupled? I'm sure you'd get a nice radiation bath, but what (if any) impact would you notice from the gravitational waves themselves in the final moments before merger?
+dt35591 It'd depend how close you were. Let's say two holes of 3 solar masses, at the low end. A rough calculation tells us that at merger their orbit would be a few miles across. A thousand miles away you wouldn't feel anything, you'd be torn to bits and your matter sucked into the holes before they'd even finished merging. A million miles away is better, you feel a brief, excruciating pain as you are spaghettified by the chaotic spacetime distortions. You'd want to be a bit further out before you got a signal that was a single, regular gravitational wave.
The cycles are very rapid, starting at tens per second and rising to hundreds. You won't feel the individual squashings and squeezings, just the disruption to your molecules. It would be quite similar to a shockwave, as it passed you it'd sort of mash you up at a molecular level. Even further out you can expect distortions to be less, effects would be on a cellular level, fading with distance until you experience nothing more severe than internal bruising. This would probably feel like a punch to you r entire body as the wave passed, just pain everywhere affected. Even further out you probably won't notice much at all.
+Gareth Dean what's a good distance if I want to gain superpowers from all this?
+dt35591
If you could see with your eyes for a second, that would be the only second you live. Given the close proximity to which human perception becomes effective, you would probably need to be within say 100,000 km to notice a binary pair of black holes. At that distance the radiation would kill you right away. It's like bathing in a Chernobyl disaster on steroids. But aside from the organic destruction, I don't think anyone really knows for sure what happens to matter near by that scene.
+Gareth Dean I just want to say I enjoy reading all of your comments on the PBS videos xD
Red
Many thanks, I enjoy PBS's videos, they light up the day each time.
Wow..Great Job LIGO and thanks @pbsspacetime for the best coverage/explanation of this historic event. I loved the teaser trailer back in October, for this feature presentation! Coincidence...I think not ;)
Question: Once we observe an event simultaneously via multiple instruments, including x-ay, telescopes and hopefully new more advance systems like eLISA, what direction are researches most excited to explore? Will we be able to map the shape of the universe? Please say Warp Drive!!
+Connor Flynn The warp drive is being worked on NOW, we may well have one before we get that observation. What will be interesting is seeing just what happens at the particle level when black holes collide.
Could you guys do an episode on the Relativity of simultaneity and the Rietdijk-Putnam argument? It's so awesome.
Does it open a window for any new technologies? It seems that even after this video I cannot imagine the benefits of it.
Well we're closer than ever to actually manufacturing a real hoverboard, we understand gravity and spacetime better than ever
+Gigatless Nothing immediately apparent, but most other things in Relativity weren't immediately apparent either. But now, GPS and Satellites have to take into account both Special and General Relativity. It might not have immediate applications now, but the math alone will probably change how we invent future products.
+Gigatless One possible application would be in the developement of faster-than-light travel, as it would have to take into account potential distortions in space-time as the spatial dimensions are warped in order to ensure proper arrival at destinations. Also, being able to detect when gravitational waves may impact earth would allow us to recallibrate GPS's for example.
+Gigatless , Are you kidding me? We just went from not being able to measure something to now being able to measure it. Now we can experiment with the right combination of heavy elements and centrifugal patterns, we can impact or deflect gravity.
+Gigatless Well, a warp drive is basically a wave in fabric of spacetime ... pretty much the same thing as gravitational wave. Interesting enough yet? :D
You said LIGO needs to 'watch' a lot of galaxies. But LIGO doesn't 'watch' anything, it just sits there and waits for the ripples.
+karljobst In a way that's watching. You hear stuff by sitting and waiting for the sound waves, you see stuff by sitting and waiting for the light waves. If you define 'watching' as purposefully looking at something then no machine like LIGO can watch, only the people using it.
Gareth Dean It's not me that defines watching as purposefully looking at something - that's the dictionary definition of it. There is a big difference between 'seeing' and 'watching'. Seeing just means perceiving in general, whereas watching means to look at something with purpose. It's just a misuse of the word. Our ears can hear any waves that come in, but that is different to 'listen to' which is analogous.
karljobst
Yeah but that's English for you. I notice that several dictionaries don't list literally's new meaning and indeed a few of the older ones list irony's first definition as relating to iron.
+Gareth Dean You sir, are the real MVP, responding everyone's questions. Kudos
Watch your inconvenience! :v
Congratulations to the physics department and gravitational waves research team at Syracuse University! You guys deserve it!!
Finally, a documentary that doesn't jump from person to person in 3 second edits.
Logic would suggest that if gravity squeezes the light out of a star until it cools and becomes a black hole then when two black holes of similar mass and degree of compression, therefore potential combine, the doubling of mass would double the gravity and increase the pressure. This would be like the second squeezing of the grapes and the combined black holes would emit light for a short time and become visible. Whether as a brown star or a brief super bright one. You chose. The waves detected are probably expanding rings of single polarity magnetic particles.
Back in the day, when we took into consideration the ease with which light travels in a vacuum, we assumed the luminiferous ether was a very rigid glass-type substance. Now we know there's no ether, but we do believe there's a "spatio-temporal fabric" and that gravitational waves are waves in this fabric. So, given the way gravitational waves spawn and propagate, what sort of material substance best characterizes this fabric? Would we still compare it to really hard glass?
Great way to explain it.
best science channel on youtube so far
MAN!!!!!!!!! this is so exciting!!! I love science!! every new discovery makes me so happy!!!!!!!
with this video can I say :
the space density can be calculated because a energy wave travel through the space; is like the sound travel on air. This space wave can be transformed into the sound according with the frequency. Nice video!
If the space wave warps too much can appear a wormhole
Professor O'Dowd, would you kindly help elaborate on the physics of gravitational waves a bit? I'm familiar with the arrangement of LIGO in WA and LA and understand the technique of the observation. My question below is about the physics of gravitational waves.
I understand that In trying to detect gravitational waves, the LIGO experiment attempts to identify a subtle change in the distance between 2 fixed points in each of its 2 perpendicular arms. Now, let's focus on one of those arms because my question is essentially around the concepts of space and distance and speed. The distance between two points at either end of each arm is continuously traversed by a beam of light. The idea is that if the distance between the two points changes, the beam of light that's being monitored will arrive at a slightly earlier or later moment than expected.
During our monitoring of the distance between two fixed points, a gravitational wave arrives, rippling the fabric of space-time between our two points. My question is: Why are able to notice this ripple at all? Why does the ripple cause the distance between our two points to change? It's not like new space is being created between our two points, right? It's not like our two points are being nudged out of place, right? Our two points haven't really moved in space at all, but rather the fabric of space between them has shrunk or expanded, correct? So, how is it that we can objectively detect this space ripple? It appears to me that in order to see the effect of the ripple, the observer must stand outside the fabric of space-time. Is the LIGO light-detection-contraption somehow operating outside the realm of space? Is light unaffected by space?
Estoy muy entusiasmado por todo esto. Vamos por buen camino !
It's weird that in the ligo merging black holes simulation, spacetime literally spiked upwards and then instantly leveled.
Plus, time dilation didn't even effect the 2 black holes when they approached eachother. Very strange..
Brilliant -thank you for the video
Small question ?
When do we get to generate ,modulate and call CQ !!!
An exciting time to be alive, indeed. Thanks for the video.
I simply love this show.
I has a question though, I saw some while ago, that we know dark matter is out there because it bends light as it pases trough, could it be that gravitational waves also bends light? If so, could we confuse dark matter with gravitational waves some times, if not always? Could also be, that the mass we miss from our calculations of the universe be the energy that gravitational waves produce, instead od dark matter?
This is really trobling me, but I have almost no idea about astrophisycs,
Thanks in advance!
Very well put together in such a short time...Though my ripples would be more excited and obvious if I was wearing that
T-Shirt :)
I love this channel
I absolutely love this channel since discovering it. I also very much prefer this host to the old one. There is something to be said for delivering complex ideas with equal parts passion and humility. Keep up the great work!!
All of those animation seem to just be stretches and contractions of space and they seem to be "moving" because of time, otherwise it would be like staring at a picture of a wave. If gravitational waves are the space-time itself stretching and contracting, what is the thing that acts like "time" that makes those waves moves? Or is it actually the whole spacetime already weavy and as we "move" through time it seems to us like space is contracting and stretching?
Didn't get the LIGO detectors configuration part. Is it able to not only detect the presence of a gravitational wave propagating through it but also can point the direction, from which the wave came? If so, how much accurate is it exacly? Do astronomers have to guess the object in question from other kinds of surveys or LIGO can pinpoint the exact location and distance ?
Tremendously awesome news! I find it amazing that even 115 years,(roughly), after Einstein wrote his work, that it has been proven over time and time again! Love this channel!!!
Question:
The sizes of the two black holes are 36 and 26 solar masses.
Some media says orbit frequency of 30 ~ 250 times a second! (this video mentions 1000 times a second?!) (WOW!!)
Schwarzschild radius of these two black holes are 106km and 76km (if I calculate correctly)
So question is - when we say the two black holes are "orbiting" 30 times a second, are we talking about two blobs of 106km and 76km radius each, orbiting each other 30 times a second (very impressive), or have their event horizons already merged and we're actually saying the singularity points are orbiting each other at that speed, already inside their new combined event horizon? (which I guess is slightly less impressive).
American Physicist, Joseph Weber developed the first gravitational wave detectors (Weber bars) in the 1960s, and published papers with evidence that he had detected these waves.
I really appreciate the work LIGO team did, in my opinion the LIGO team proved the already proved theory.
In my opinion there is nothing new is proven so nothing is going to change. Probably apart from more investment as the theory reinforced by modern technology.
I note that in the PBS introduction aLIGO was 'switched on' (commenced scientific observations) on 18th September 2015, but later the Black Hole merger and associated GW detection was observed on 14th September 2015. I have also seen both these dates mentioned in other sources. The aLIGO team in their paper announcing the GW detection name the event as GW150914 with the date embedded in the event name.
Is there an explanation for this apparent anomaly of 4 days? Was aLIGO in a pre-science mode configuration at the time?
+John Proctor As we mentioned in the previous video on gravitational waves, the rumour was that the detection was in the "engineering data". There were eight engineering data-collection stages before the official turn-on date on September 18, and with each stage the sensitivity increased. During the 8th aLIGO was at full sensitivity (for now) and it detected this event as soon as it was possible for it to be detected. This isn't so surprising. Medium-level optimistic estimates of the rate of black hole-black hole mergers suggest that events should be detected every few weeks. So why haven't they seen more since that first one? They have, they just haven't released those findings yet.
+PBS Space Time
So the observation of the double black hole (BH-BH) merger GW150918 was made during the 8th engineering data-collection run - this explains the apparent anomaly in the dates., Thanks. This was not mentioned in the GW detection announcement paper, Abbott, P. B. et al., 2016, Phys. Rev. Lett., 116, 061102 which can be retrieved from DOI: 10.1103/PhysRevLett.116.061102.
It is very interesting to note that further GW observations have been made but not published yet. My personal interest here is in the predicted detection rates at the current aLIGO sensitivity level and corresponding horizon distances. At the time of the discovery in September I was completing an MSc student project using the Swinburne University supercomputer to predict compact binary merger rates for neutron stars (NS) and black holes (NS-NS, NS-BH and BH-BH), and use this data and the published aLIGO horizon distances to calculate predicted GW event detection rates from coalescing binary systems. I have estimated approx 5 BH-BH merger detections per year during observational science run O1.
It will be interesting to hear if there has been rumours of the detection of a BH-NS merger, although my calculations predict an NS-BH merger detection rate of only 1 event every 5 years or so.
+John Proctor That's right. The rumour that it was in the engineering data came out soon after the first detection, but this was confirmed to me verbally by a LIGO team member. I don't think it's a secret, just not considered relevant to the science. That same source strongly indicated that there are no NS events yet, so your predictions hold up. They're also consistent with the event rate predicted by LIGO. As for the BH-BH rate, I would say that the current event rate puts your prediction only very slightly on the low side - I think we're seeing something like twice that. But then, what's a factor of two between astrophysicists? I'm curious - do your simulations predict such massive BH mergers?
+PBS Space Time The GW150914 BH masses? I was hoping to raise a question that point myself.
(1) As we know Abbott et al. (2016) determined the initial BH masses as 36 and 29 Msun coalescing to a single 62 Msun BH with the balance of 3.0 Msun C^2 being radiated in GW energy in a fraction of a second. That's an extremely powerful event.
(2) For my student research project I used the Binary Star Evolution code running on the Swinburne machine. This allows input values of ZAMS progenitor masses up to only 100 Msun and consequently I get only BH remnant masses up to 12 Msun for solar regime metallicity (z=0.02) and up to 16 Msun at z=1/10 solar.
So the published masses came as a bit of surprise. It would seem that the BSE code should be modified to accommodate higher ZAMS masses to produce these observed remnant BH masses.
(3) If there are a significant population of these big guys around it will probably explain higher detection rates that are now being observed (due to the greater Horizon Distance and therefore detection volume) . In my study I have used the 10 Msun 'average' BH taken from the Abadie et al. (2010) paper of the LIGO collaboration.
(4) I am hoping that when an NS-NS or NS-BH merger is detected in GW we can get a collocated Gamma Ray Burst (GRB) detection (from SWIFT or Fermi) in the electromagnetic spectrum that will enable the merger event to be pinpointed in its host galaxy.
Anyway this is an exiting time to be around and involved in all this.
+John Proctor Reading one of the papers cited by Abbott et al. (2016): "On the Maximum Mass of Stellar Black Holes" - Belczynski et al. (2010) ApJ, 714, 1217 - BH of mass up to 80 Msun can be simulated by permitting BH progenitor ZAMS masses up to 150 Msun, together with other factors such as very low metallicity galaxies (Z=0.0002), low values of stellar wind mass loss during the MS, LBV and W-R phases, and significant mass fallback during the progenitor supernova explosions could (possibly) account for these high-mass BHs. I am not to convinced by the argument and the 'stretched' simulation parameters - but certainly such very high-mass binary BHs have now been observed as confirmed by the GW signal data!
Hey, I got 2 and half questions!
1. Since we know the gravity could messing up space-time, Could this G-wave travel faster than light? if so, Could we use it to send something like when you put a ball on carpet or bed sheet and make waves?
2. Can we calculate the ratio of "Universe's Total Space" per "Total Space that been suck into every black holes in the universe"? or Ratio of Rate of change of these 2 things?
I love the truly scientific approach to the black hole FX in Interstellar. It's so accurate that we're seeing it in science documentaries now. :D
How close would an event like this need to be for us to physically feel the gravitational waves?
I noticed that the video for the discovery of gravitational waves was posted on October 22nd followed by the Alcubierre Warp Drive on October 28th. Considering that the discovery has been made official...would it be possible to explain if this reinforces the possibility of an Alcubierre Warp Drive? If spacetime can be deformed by a merger, would it confirm the possibility of creating a bubble? Is this new the "era" of astrophysics (aside from observing other events using gravitational waves)?
I have always had difficulty in dealing with word problems, but can you describe the topological harmonics I expect the heavy "mass" interactions to have shown?
the series has done a really good job in reaching toward the illusion of mass; At some point we must deal though, with a harmonic that describes acceleration. When that is done, we can obtain something that applies to the phenomena we can observe.
I'm stuck, though with trying to review math I learned long ago, and trying to learn how to apply it to descriptive word problems.
I know that many people are interested in what they call "real" world problems, and the series deals with those. Perturbations in gravitation are perturbations in time (as a dimension of spacetime), Einstein pretty much said, from my reading of his work.
Your motion diagram in 2 dimensions was an illustration of that.
Topology gives us a tool for 'picturing" spacetime and of folding or compressing dimensions, and seems to me more descriptive than visualizations. I hope you will talk about harmonic distortion as a function of spacetime...
I need the "visualization" and others might benefit from their more materialist(!) perspective..Thanks!
A question from a physics laymen to those more advanced: if eLIGO detects gravitational waves by the difference to the combined laser wavelengths (a difference to the destructive interference pattern following curvature of space-time in each individual pathway), how is it that the lasers themselves are not exposed to a stretching of time, rather than spatial lengthening alone, since EM waves are, too, subject to gravitational waves? Would this not cause the pattern to remain the same if there really is a gravitational wave? Thank you for your time.
If earth was 1 light year from the current event detected by LIGO, what would the effect, if any, be felt on earth? How much larger would the amplitude of gravitational waves measure if one light year away (as compared to our current distance and current measurement)? At what distance would Earth have to be from this merger of two black holes to feel the effects of gravitational waves? How far away from this merger of black holes would the earth have to be, in order to survive such an event?
Almost immediately detected a gravity wave? What does this part mean? The idea that they turned the machine on at the precise moment (I realise that it was probably not the exact moment but I will work in absolutes to emphasise my point) that a gravity wave came by sounds more incredible than the fact they detected the wave in the first place. I mean what are the odds of that with our current understanding of the frequencies of events in the local universe that a wave would come by? How many of these enormous events are happening around us if when we turn on our machine to find one so soon? Great videos by the way,
So when are we getting the results for the last couple of contests? I'm excited to see who won.
My question is who is starting the mathematical theorizing about using these ripples in space time or warped space for space/time travel. I've heard the possible suggestion of using ripples in space time for travel but with the detections of actual warp space in the form of gravitational waves it really opens up the possibility. Amazing stuff.
As exciting as this discovery truly is we will never see anything come from it in our lifetimes.
I saw a question answered by Professor Jon Butterworth on gravitational waves that are created inside a black hole's event horizon:
"The gravitational waves that escaped the merger and eventually traveled to us were produced outside the event horizons of the original (and final) black holes, so that they are not coming from inside the event horizons. Since gravitational waves only propagate at the speed of light, they cannot escape from inside the event horizon of a black hole. "
But because gravitational waves represent a disturbance in the fabric of space-time itself, and this includes the fabric of space-time inside the event horizon, I don't see how it could be contained by the black hole's gravity. Can you help me understand how this happens?
You cannot tether cloud cities on Venus to the ground: the winds at any realistic altitude are so strong that they would destroy any structure that we can economically build, not to mention making docking and undocking a suicide task.
What you should do is float following the wind and do small corrections to avoid floating to far North or South.
Also, we have no idea of what effect on our health would Mars gravity have. We only have two data points, 0 G and 1 G. Hard to interpolate from that on something as complex as the human body.
Very excited about gravitational waves, thanks for the news!
I'd like a representation of gravitational waves in the same diagram as the photon clock problem. Or better yet, a gravitational wave photon clock problem challenge.
why does this not have a billion views