+HighIQuit His IQ was aprox 160 while we are hovering around the 100s.. They should find a way for humans to reach further heights..... that would open even more possibilities in general...
+Itchy 0ne Grip IQ crap! Einstein never took an IQ test at any point. In fact Einstein did not do much well in the university at that time. You guys come up with crap IQ score for Einstein just because he is intelligent.
+HighIQuit ....and the flip side is that science is under constant attack by one segment of the U.S political system.....and the majority of the politicians are scientifically illiterate...
All the science gurus have had vids like this one on standby for months now. Word leaked out last year about this find but LIGO is apparantly known to be diligent in their testing and wanted to be absolutely certain before they blurted out Eureka! I was surprised because i heard it might be up to a year before they announced officially, but it only took a few months. I wonder if that means they found more shifts?
Michael McMurray actually right before i read your comment, i watched a vid on it and it claims the LIGO team found signs of g waves in their test runs in the very first week before officially running full power, and since then they have indeed been finding more waves, announcements sure to follow in the coming months after enough evaluation.
+lietdune3187 Absolutely. A really big deal. I was disappointed by his ending though. Technically we will not be using as he said "gravity", but rather the ripples in space-time. Which I suppose is what we refer to as gravity. And for the general public, I suppose is reasonable. But I'm a bit of a pedant. Great news though.
+lietdune3187 how? how will you be able to explore this? you don't have a clue what's going on so shut your mouth and go to church for real explanation.
+Clint Flicker I suggest you follow your own advice. That way you can get your bedtime story read to you, and the grown-ups can talk about important matters.
PathosFear It's easy to belittle. It's harder to explain. Tell me, how is this "discovery" going to help you in your life? I've discovered something that helps me, as well as billions of other people around the world, in my daily life. Don't be jealous that this "discovery" means absolutely nothing in the grand design of things.
Clint Flicker Well, I only belittle where belittling is due. I don't give a shit about your personal discoveries about fictitious gods. Come back when you have any actual proof to present about their existence... You know, proof that isn't "for the bible tells me so." Maybe God can then explain the whole gravitational wave thing for you, because frankly, I think that is what it's going to take to get through that thick barrier of indoctrination you got built up there. Until such a time, stay out of scientific discourse, if religion is the only thing you will bring to the table.
This is the biggest news of this century. Last century's was Einstein's theories of Relativity and the Photoelectric effect. Einstein still makes the biggest news hundred years after he's gone
Einstein was a beggar in royal robes. Relativistic Physics and Quantum Mechanics are atomistic constructs. The aether is real and everything is electromagnetism and electricity
+Kassyni Savior I hope they can get down to business on finding out more about dark matter, especially with the help of this. And hopefully that will help reform even more theories.
+DANG JOS yeah i think that too.. if the thing they are trying to detect is so minuscule then how can they absolutely rule out everything but what they had no idea or clue about. that's crazy! A physicist seems like a good job. once you get past the schooling and shit.. you can practically be a story teller... and there's no editor in chief to kick your ass when you tell a tall tale... that tale will just get lost in the hype of the latest tale.
***** Well that's not actually true. That's one of the great things about physics and many other branches of modern science. There is someone to make sure you're not telling a tall tale. It's called peer review. Other physicists check that the scientists doing the experiment didn't screw up. And if you don't trust that, you could even look at the paper yourself. This is a big difference between actual science and pseudoscience
I'm just happy for the scientists. At the end of the day I will never understand the mathematics behind it but when you see scientists dedicating their lives to this especially in the theoretical field its great to know that they know their work isn't just a science which may have already reached its potential of discovery
I see this comentary below and repeat it "I lived to see the Higgs boson and the gravitational waves being found.' This is incredible and fascinating for me because the feeling awesome that is accompany these new discoveries in my lifetime. The science is amazing!!!
I'm blown away by the fact that they can make sure they detected the gravitational waves, omitting all other phenomena (vibrations of the earth crust, interference, uncertainty in measurement), and because these gravitational waves should be coming from all directions from space, maybe they are cancelling each other out at some point.. I have no way of wrapping my head around this subject. Kudos to science, I feel so left behind trying to understand it.
Rabii Chadli That's why two detectors at either end of U.S. were built. A tectonic event (to use your example) would affect them differently due to relative distance and direction. Also, the arrival time to the two detectors would match propagation speed of tectonic waves. In this case, the same gravitational event affected both detectors equally (due to the space distortion) and the time difference between each detector's readings match its propagation at light speed as a gravitational wave would spread.
I see, good point Brian Deschene. How about if this force was generate from the earth rotation? if the earth core has liquid iron, it could generate this shift the laser detected? That's why we need to move the measurement away from earth. Can we move the instruments into space, say build a number of satellites to work together to detected this.
I like how people of science actually show you what they used to find out the nature of the universe, instead of shouting it was privately revealed to them or that they read in in some old book
Brian, 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?
+David Butler That's an Interesting point you have raised David, I initially thought the same as too. But just off the top of my head... If the waves are propagating through space-time, they would need to propagating with sufficient velocity to pass through the event horizon into "normal space" (some value greater than 300,000 km/s). But as they can only travel up to and at "c" the wave must also follow the rules. maybe we are getting into the realm of gravitons...! ;-)
+Stuart Geddes But it is the warp inside that is changing with gravitational waves. It sounds like a circular argument to say 'changes in the strength of the gravitational field' cannot move out beyond the horizon because of the strength of the gravitational field'. Do you see the problem I'm having.
+David Butler The spacetime field inside the event horizon has been so distorted by the black hole's gravity that it is folding up on itself. Gravity slows time, and it would take an immense amount of time for any signal to escape from an event horizon. You can see why they use the term 'event' in the name. Though the waves do propagate, our time here in our lower gravity region is moving so much faster than near the black hole, that it would take basically forever for it to get out. If it only moves at the speed of light. Gravity bends spaceTIME.
+David Butler I understand your point. The gravity of the black hole shouldn't affect the waves itself. Anything travelling through space-time cannot escape from inside the event horizon. But since the gravitational waves are ripples in space-time itself, it should have nothing to do with the gravity. But what I think the professor meant is that, the waves generated inside the event horizon stay inside and do not propagate outside and we are only observing the waves generated outside it. It is known that gravity can distort space-time. So the waves generated at 'c' at the center might get slowed down infinitely as it reaches the event horizon. Thus, keeping it inside. This might be what's happening.
The only reason the interference pattern changes shape is because a gravitational wave is "roll by" like he said.So assuming that the interference waves are free of any disturbance or calculated compensation of know disturbance at first how do you know that what is passing or let pass thru is gravitational waves only or even gravitational waves for that matter.Could be something else we don't even know exist?
Hello Briane Greene, I've few questions for you if you can answer them, 1) As per Einstein , there is no gravity but actually stars are sitting on and moving on fabric of space.time, for this be true, is their a weight of spacetime fabric so it can hold giant stars on it? 2) If fabric of spacetime is "something" rather than "nothing", the star's should crush on the spacetime fabric generating resistance, heat .. does this happen? 3) Some stars dont follow a specific rotation path in 2-D flat surface but some follow elliptical route in 3D how does this happen? how does the idea of space time as rubber sheet can explain rotation of stars in 3 dimentions 3) why the stars are rotating rather than just hanging in fabric of space time? and why from several billion years?
This is the first video I've seen showing how this discovery was made so forgive me if this question sounds stupid. How do they know gravitational waves are the cause and not seismic activity? Feel free to tell me to do more research.
+burnininhell Do more research. Just kidding. You should assume that the hundreds, if not thousands of scientists and engineers involved in this research have a sufficient understanding of their work to rule out seismic activity. Besides, seismic activity would not be mistaken for this sort of signal, for reasons that are beyond the scope of this comment.
That is great news for scientists out there; great job people. I had a few questions following the announcement that still trying to figure out. The most recent one popping in my head is, how were the two LIGO detectors been able to see the same frequency pattern, when their "L" shaped interferometers are facing in different directions (south and west)?
Um, actually gravitational waves are caused by "your hand jostling in space" (0:55). It's just that the waves formed would be soooo small they would be practically undetectable. In fact, any asymmetrical movement in spacetime does cause gravitational waves.
Brian Greene explains concepts real awesomely... Wish he was my physics teacher :P I would never forget anything taught by you coz you make it so easy...
Wait a minute, this video implies that the tunnel length is changing, so in one arm of the tunnel, light has to pass more distance than the other arm, casing the waves to become out of sync from each other, causing interference. But if spacetime itself is stretching, then the tunnel arm and the light waves passing through it will also stretch in equal amount is not it? so the waves will never go out of phase. its like drawing a wave shape in a sheet of rubber and pulling it. we should never get an interference pattern in this setup.
Wow, what a great comment. And I am not being sarcastic. Perhaps you are a physicist? In any case, your comment gave me pause. But lets consider the effect of warped space on various entities. I assume we are both in agreement that this is the crux of the matter, warped space, whether in waves or not. Well what is the difference between warped space on light versus normal matter? We all know that if you toss a baseball with a small space curvature, say the earths gravity, the effect is quite large. It curves back to earth. But if you fire off a laser beam in earths gravity, the effect is very miniscule. So as a rough estimate, any g wave passing by should affect matter much more intensely than light. Just my two cents.
+Marv3Lthe1 In a vacuum, light always travels at the same speed (the speed of light), regardless of any spacetime stretching (and regardless of inertial reference frame). Thus when the gravitational wave passes by LIGO, one tunnel contracts and one expands, and the laser beam must take less time to traverse the contracted tunnel as compared to the expanded tunnel. Thus there will be interference effects. I believe that there will be a slight frequency change in the beam as the gravitational wave passes by, but this doesn't affect the speed of the beam and I don't believe it would have any effect on the experiment.
Chill, guys. Gravitational waves do change the wavelength of light. But, the detection aLIGO made was based on the interference pattern of the waves due to change in phase. As they are 180 deg out of phase in default condition, a change in length of the tunnel will make them go in-phase to some degree, causing a detection of light at the detector. A change in wavelength of light due to g-waves will depend on the wavelength of the g-wave itself. If it is short enough, the light will be reverted back to its original wavelength before reaching the detector. So, the shape and type of detector will change according to the type of g-wave being observed.
What if the world is stretching and contracting like a balloon due to geological phenomena (that we don't know yet), not due to gravitational waves?. Ideally this should be done in space at three fixed references? I'm confused!
+light kira but @1:33, it seems the earth is distorting, it should be, right?. coz if the space is distorting then anything in it should follow it's distortion.
Wow! That's incredibly briefed. Thanks a lot, sir! :') But, I have only one question, how the gravitational waves squeeze and stretch the planet (Or any astrophysical body in front of it)?
I wish to be immortal, but not for the sake of amassing wealth or anything trivial. I just wanna see how far we can go with scientific breakthroughs. I am so happy to be alive for this one!
Goes nicely with string theory, does it not? Oscillating gravitons. Reminds me a great quote over 100 years ago. “If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.”
I have seen no explanation of why we attribute the gravitational wave measured by LIGO specifically to the two colliding black holes. How do we know to link the wave to that phenomenon aside from the massive energy created by the collision?
I just had one question, from my understanding the gravitational waves from the event bend space and so we've picked up on the waves. How did they determine these were black holes and their sizes. Im not a science major, apologize if this is an ignorant question.
I'm confused, there were a couple of videos of this guy explaining string theory but then they make them private and cannot watch them anymore :/ anyone else?
Good question. I believe both detectors (Louisiana and Washington) witnessed the same signal by the difference of time needed for gravity waves to travel (I.e., near the speed of light) to reach both detectors. An earthquake would produce two signals in the same way, but earthquake waves don't travel anywhere near the speed of light so the detection time between both detectors would be much, much larger.
It could have been geological. Maybe the constant churning and rotation of the Earth's core produced these extremely minute rhythmic fluctuations on those mirrors. It could have been many other things that produced these extremely minute rhythmic fluctuations on the mirrors. The tectonic plates constantly grinding against each other? It could have been something other than "gravitational waves" of a couple of distant black holes revolving around each other gazillion light years away.
Ligo has two detectors so that rules out local disturbances. And the waves are more like fingerprints that fit what was predicted. These are not just a little bump, its way more complex than that.
James01100011 Those two detectors are not enough if the rhythmic perturbations on the mirrors were caused by some activity within the Earth's core. Both detectors are on the Earth's surface. The recorded signature matched a predicted signature closely, yes. Is that conclusive enough for attributing it to gravitational waves caused by black holes/quasars orbiting each other thousands of light years away? I don't think so. This wave signature evidence is not conclusive enough for arriving at such a conclusion.
Hang on a mo... this confirmation is amazing, but, why does the animation show the 'stretching' perpendicular to the direction of compression? One LIGO arm was compressed along its length, the other along its width, ie, the length djd not change. Is this just a case of simplifying?
I don't know much about this setup with the lasers and I apologize in advance if it is already explained but I am only wondering if there is anything else that could potentially disrupt the interference pattern of the lasers or is it 100% certain 2b "gravitational waves"? In other words, can it be proven that it is indeed gravitational waves and not some other phenomena that is disturbing the interference pattern of the lasers and if so, how?
I have a question, what would happen if we could put Earth and Moon at rest and add feather on oposite side of Moon, so both could fall on Earth at same time. There shouldbe few possibilities; 1. feather and Moon would fall on Eart at same time, 2. Earth and Moon would exchange gravity fields, feather distance from Earth would first encrease and after it would speed up, because of combined gravity distortion from Earth and Moon. If anybody know,i would appriciate short explanation.
With all due respect, What happened to ‘The speed of light in a vacuum is the same for all observers, regardless of the motion of the light source’? As I understand it: Observer ‘A’ at the ‘A’ tube mirror will not be able to measure a change in the distance between the laser and the mirror at any time. From his perspective they are fixed in place. His Tape Measure may expand and contract due to the ripples in spacetime but it will always show the laser to mirror distance to be the same. That's Relativity. Likewise, one photon will always take the same amount of time to reach the mirror because the distance never changes (from his perspective). Observer ‘A’ will never measure a photon going faster or slower than the known speed of light. Just like his Tape Measure may expand and contract, his wristwatch may speed up or slow down as spacetime fluctuates. This is why the speed of light in a vacuum is constant. That’s the “Time” in “Spacetime”. Of course this is also true for Observer ‘B’ at the ‘B’ tube mirror. But for Observer ‘C’ at the LIGO detector, who also shares the same perspectives as Observers 'A' & 'B'. Postulate #2 of Einstein’s Special Relativity does not apply. Why is that?
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
It's amazing a mind that lived 100 years ago knew about this. A true brilliant mind.
+HighIQuit His IQ was aprox 160 while we are hovering around the 100s.. They should find a way for humans to reach further heights..... that would open even more possibilities in general...
+Itchy 0ne Grip IQ crap! Einstein never took an IQ test at any point. In fact Einstein did not do much well in the university at that time. You guys come up with crap IQ score for Einstein just because he is intelligent.
+Itchy 0ne Grip IQ, EQ.... All insignificant next to the power of the concentration and level of focusing ability
+HighIQuit ....and the flip side is that science is under constant attack by one segment of the U.S political system.....and the majority of the politicians are scientifically illiterate...
+Waryaa Moxamad Ahh, the infamous "I am not a scientist, *but* " catch phrase politicians just love...
Nice explanation. And posted within the first hour of the official announcement being made. :)
+Wayne Herman subbed as well, good looking out..
+Physics Videos by Eugene Khutoryansky However they have known about this since September 14 2015
All the science gurus have had vids like this one on standby for months now. Word leaked out last year about this find but LIGO is apparantly known to be diligent in their testing and wanted to be absolutely certain before they blurted out Eureka! I was surprised because i heard it might be up to a year before they announced officially, but it only took a few months. I wonder if that means they found more shifts?
Michael McMurray actually right before i read your comment, i watched a vid on it and it claims the LIGO team found signs of g waves in their test runs in the very first week before officially running full power, and since then they have indeed been finding more waves, announcements sure to follow in the coming months after enough evaluation.
Michael McMurray i felt taller for a moment just now, did you?
I love that he's bouncing up and down as he's demonstrating the affect of the waves.
I lived to see the Higgs boson and the gravitational waves being found. :')
+Rodrigo Appendino and you don't understand any of them
saul castillo Yes, I understand.
We are lucky
Nobody can explain this stuffs seriously. we know only 0.1% of universe's mysteries.
I said I understand Higgs boson like a physics student. I didn't said I understand everything we humans don't understand yet.
There is no end to human creativity and innovation. Proud moment for us all .
this guy is an awesome communicator
How does this not have a million views yet? Brilliant explanation. Thank you.
Bcz all persons are not capable to understand this 🙃
The significance of this discovery cannot be over stated. It is truly a new sense to explore the world with like hearing and seeing.
+lietdune3187
Absolutely. A really big deal. I was disappointed by his ending though. Technically we will not be using as he said "gravity", but rather the ripples in space-time. Which I suppose is what we refer to as gravity. And for the general public, I suppose is reasonable. But I'm a bit of a pedant.
Great news though.
+lietdune3187 how? how will you be able to explore this? you don't have a clue what's going on so shut your mouth and go to church for real explanation.
+Clint Flicker I suggest you follow your own advice. That way you can get your bedtime story read to you, and the grown-ups can talk about important matters.
PathosFear It's easy to belittle. It's harder to explain. Tell me, how is this "discovery" going to help you in your life? I've discovered something that helps me, as well as billions of other people around the world, in my daily life. Don't be jealous that this "discovery" means absolutely nothing in the grand design of things.
Clint Flicker
Well, I only belittle where belittling is due. I don't give a shit about your personal discoveries about fictitious gods. Come back when you have any actual proof to present about their existence... You know, proof that isn't "for the bible tells me so." Maybe God can then explain the whole gravitational wave thing for you, because frankly, I think that is what it's going to take to get through that thick barrier of indoctrination you got built up there.
Until such a time, stay out of scientific discourse, if religion is the only thing you will bring to the table.
What a great time to be alive to see history being made before our eyes!
This is the biggest news of this century. Last century's was Einstein's theories of Relativity and the Photoelectric effect. Einstein still makes the biggest news hundred years after he's gone
+Astro Physics I wish the headlines had been "Einstein: Right Again!"
It would have been very appropriate.
+Astro Physics actually he's only been gone 60 years. ;)
+Kirhean Well, he was dead wrong about probability and QM, wasn't he?
Einstein was a beggar in royal robes. Relativistic Physics and Quantum Mechanics are atomistic constructs. The aether is real and everything is electromagnetism and electricity
@@Nautilus1972 he's the one who discovered Quantum entanglement
Lord I hate being mortal!
Immortal would be worse
+Adam Levin I'd guess there are more people willing to try the former, rather than accept the latter. It's the foundation of religion, after all.
+Adam Levin What if you were technically immortal but can choose when to die?
+Jolly Joel Thats what i want.
+Adam Levin well, i would be happy with a few thousand years too :P
Best explanation of what happened and what it means of all the RUclips and science blogs out there.
The ending statement about waves of light and now gravity left me in awe. Looking forward to all the new discoveries!
+Kassyni Savior I hope they can get down to business on finding out more about dark matter, especially with the help of this. And hopefully that will help reform even more theories.
Sir u are brilliant in explaining quantum ..from pakistan
When hearing this news I screamed out in delight this morning at breakfast only to have my wife and children go "oh Dad"
+Scott Leaf
I can certainly identify with you there m8.
lmao
+Scott Leaf I think they hate you as much as I do!Buy, a pipe, Space Cowboy!
+Scott Leaf You screamed out in delight? GTFOH.
aye 'tis a great time to be a nerd. rulers of Wolf 359 ( yes it real)
How can anyone dislike this video
It's outdated bat shit crazy talk. Gravity is not the Sol operator of the cosmos.
...
+Powdered Toast Man You know they'll probably say there's another explanation for it or it was just noise
+DANG JOS yeah i think that too..
if the thing they are trying to detect is so minuscule then how can they absolutely rule out everything but what they had no idea or clue about.
that's crazy!
A physicist seems like a good job.
once you get past the schooling and shit..
you can practically be a story teller... and there's no editor in chief to kick your ass when you tell a tall tale... that tale will just get lost in the hype of the latest tale.
***** Well that's not actually true. That's one of the great things about physics and many other branches of modern science. There is someone to make sure you're not telling a tall tale. It's called peer review. Other physicists check that the scientists doing the experiment didn't screw up. And if you don't trust that, you could even look at the paper yourself. This is a big difference between actual science and pseudoscience
I'm just happy for the scientists. At the end of the day I will never understand the mathematics behind it but when you see scientists dedicating their lives to this especially in the theoretical field its great to know that they know their work isn't just a science which may have already reached its potential of discovery
I see this comentary below and repeat it "I lived to see the Higgs boson and the gravitational waves being found.'
This is incredible and fascinating for me because the feeling awesome that is accompany these new discoveries in my lifetime. The science is amazing!!!
I'm blown away by the fact that they can make sure they detected the gravitational waves, omitting all other phenomena (vibrations of the earth crust, interference, uncertainty in measurement), and because these gravitational waves should be coming from all directions from space, maybe they are cancelling each other out at some point.. I have no way of wrapping my head around this subject. Kudos to science, I feel so left behind trying to understand it.
The power of the Michelson-Morley setting is awesome.
Who is going to get the Nobel prize for this? Someone definitely deserved it.
what's about the tectonic movement of the earth? it can also influence the measurement?
That's why we need to confirm this finding by setup the same setup on the moon, then compare the wave frequency and time.
Rabii Chadli
That's why two detectors at either end of U.S. were built. A tectonic event (to use your example) would affect them differently due to relative distance and direction. Also, the arrival time to the two detectors would match propagation speed of tectonic waves. In this case, the same gravitational event affected both detectors equally (due to the space distortion) and the time difference between each detector's readings match its propagation at light speed as a gravitational wave would spread.
I see, good point Brian Deschene. How about if this force was generate from the earth rotation? if the earth core has liquid iron, it could generate this shift the laser detected? That's why we need to move the measurement away from earth. Can we move the instruments into space, say build a number of satellites to work together to detected this.
I like how people of science actually show you what they used to find out the nature of the universe, instead of shouting it was privately revealed to them or that they read in in some old book
Brian,
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?
+David Butler That's an Interesting point you have raised David, I initially thought the same as too.
But just off the top of my head... If the waves are propagating through space-time, they would need to propagating with sufficient velocity to pass through the event horizon into "normal space" (some value greater than 300,000 km/s). But as they can only travel up to and at "c" the wave must also follow the rules. maybe we are getting into the realm of gravitons...! ;-)
+Stuart Geddes But it is the warp inside that is changing with gravitational waves. It sounds like a circular argument to say 'changes in the strength of the gravitational field' cannot move out beyond the horizon because of the strength of the gravitational field'. Do you see the problem I'm having.
+David Butler The spacetime field inside the event horizon has been so distorted by the black hole's gravity that it is folding up on itself. Gravity slows time, and it would take an immense amount of time for any signal to escape from an event horizon. You can see why they use the term 'event' in the name. Though the waves do propagate, our time here in our lower gravity region is moving so much faster than near the black hole, that it would take basically forever for it to get out. If it only moves at the speed of light. Gravity bends spaceTIME.
+David Butler I understand your point. The gravity of the black hole shouldn't affect the waves itself. Anything travelling through space-time cannot escape from inside the event horizon. But since the gravitational waves are ripples in space-time itself, it should have nothing to do with the gravity.
But what I think the professor meant is that, the waves generated inside the event horizon stay inside and do not propagate outside and we are only observing the waves generated outside it. It is known that gravity can distort space-time. So the waves generated at 'c' at the center might get slowed down infinitely as it reaches the event horizon. Thus, keeping it inside. This might be what's happening.
+David Butler Still waiting for Hawking to ring in here. Wasn't it he who proved light can in fact escape a black hle?
I cannot wait to see and hear what we can do!
The only reason the interference pattern changes shape is because a gravitational wave is "roll by" like he said.So assuming that the interference waves are free of any disturbance or calculated compensation of know disturbance at first how do you know that what is passing or let pass thru is gravitational waves only or even gravitational waves for that matter.Could be something else we don't even know exist?
Epic! New way to understand everything again.. A new era ahead.
so, what's on the other side of that space time fabric?
+JoeOf91 a restaurant
+JoeOf91 wormholes are said to be holes in space time so anywhere else in the universe could be on the other side
Kim kardashian's other cheek.
+JoeOf91 Obviously another universe.
an infinite numbers of realities
Thanks so much for the explantion! Obrigada!
Brian Greene straight killin' it
Hello Briane Greene,
I've few questions for you if you can answer them,
1) As per Einstein , there is no gravity but actually stars are sitting on and moving on fabric of space.time, for this be true, is their a weight of spacetime fabric so it can hold giant stars on it?
2) If fabric of spacetime is "something" rather than "nothing", the star's should crush on the spacetime fabric generating resistance, heat .. does this happen?
3) Some stars dont follow a specific rotation path in 2-D flat surface but some follow elliptical route in 3D how does this happen? how does the idea of space time as rubber sheet can explain rotation of stars in 3 dimentions
3) why the stars are rotating rather than just hanging in fabric of space time? and why from several billion years?
Best explanation so far!
Yeah, Its really nice explanation of Detection of Gravitational waves.....................................
Gravitational waves are making waves in Science!!! :D
+graduator14 crash bandicoot
Spyro
+graduator14 I'm trying to live to the confirmation of M-theory (Brian Green's field of research, by the way - in theoretical physics).
Absolutely breathtaking discovery! Einstein was indeed a genius mind.
This is the first video I've seen showing how this discovery was made so forgive me if this question sounds stupid.
How do they know gravitational waves are the cause and not seismic activity?
Feel free to tell me to do more research.
+burnininhell Do more research. Just kidding. You should assume that the hundreds, if not thousands of scientists and engineers involved in this research have a sufficient understanding of their work to rule out seismic activity. Besides, seismic activity would not be mistaken for this sort of signal, for reasons that are beyond the scope of this comment.
wow very nice video,far better than any other of this topic.
That is great news for scientists out there; great job people.
I had a few questions following the announcement that still trying to figure out. The most recent one popping in my head is, how were the two LIGO detectors been able to see the same frequency pattern, when their "L" shaped interferometers are facing in different directions (south and west)?
+Xe M They didn't. The patterns were inverted from each other just as you'd expect. They mention it in the paper.
Um, actually gravitational waves are caused by "your hand jostling in space" (0:55). It's just that the waves formed would be soooo small they would be practically undetectable. In fact, any asymmetrical movement in spacetime does cause gravitational waves.
Amazing. Detection in the future using gravitational waves.
Brian Greene explains concepts real awesomely... Wish he was my physics teacher :P
I would never forget anything taught by you coz you make it so easy...
U r absolutely right.he is an amazing explainer of the difficult topics.i watch his videos 1000 times because of the kind of his explainstion
Thank you for explaining the concept clearly. Every other source starts and stops with a "ripples in a pond" analogy.
Excellent explanation. Big up to Einstein and his boys.
simple impressive explanation of a complex experiment. thank you sir.
I want the long explanation
Channel: PBS Space Time
:)
+Lee Noo here is the full explanation, journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.061102#fulltext
Ripples of Gravitational Waves -> MIND BLOWN.
Geez, how is that computer animation made to simulate the gravity waves ? Awesome work !
Thanks for such a visual explanation! I understand the process now :)
Brian Greene is the man
Where can I find more on the detection method of gravitational waves? Curious why we have only detected 1 when we're swimming in gravitational waves.
Thankyou sir, for a wonderful explanation about Gravitational Waves 3.10 min video worth watching ......
Hopefully the long explanation will come soon, somewhere on youtube c:
Wait a minute, this video implies that the tunnel length is changing, so in one arm of the tunnel, light has to pass more distance than the other arm, casing the waves to become out of sync from each other, causing interference.
But if spacetime itself is stretching, then the tunnel arm and the light waves passing through it will also stretch in equal amount is not it? so the waves will never go out of phase. its like drawing a wave shape in a sheet of rubber and pulling it. we should never get an interference pattern in this setup.
Wow, what a great comment. And I am not being sarcastic. Perhaps you are a physicist? In any case, your comment gave me pause. But lets consider the effect of warped space on various entities. I assume we are both in agreement that this is the crux of the matter, warped space, whether in waves or not. Well what is the difference between warped space on light versus normal matter? We all know that if you toss a baseball with a small space curvature, say the earths gravity, the effect is quite large. It curves back to earth. But if you fire off a laser beam in earths gravity, the effect is very miniscule. So as a rough estimate, any g wave passing by should affect matter much more intensely than light. Just my two cents.
+Marv3Lthe1 In a vacuum, light always travels at the same speed (the speed of light), regardless of any spacetime stretching (and regardless of inertial reference frame). Thus when the gravitational wave passes by LIGO, one tunnel contracts and one expands, and the laser beam must take less time to traverse the contracted tunnel as compared to the expanded tunnel. Thus there will be interference effects. I believe that there will be a slight frequency change in the beam as the gravitational wave passes by, but this doesn't affect the speed of the beam and I don't believe it would have any effect on the experiment.
+Marv3Lthe1 As Paul stated above, speed of light will not be affected by the waves, only the space around it.
Chill, guys. Gravitational waves do change the wavelength of light. But, the detection aLIGO made was based on the interference pattern of the waves due to change in phase. As they are 180 deg out of phase in default condition, a change in length of the tunnel will make them go in-phase to some degree, causing a detection of light at the detector.
A change in wavelength of light due to g-waves will depend on the wavelength of the g-wave itself. If it is short enough, the light will be reverted back to its original wavelength before reaching the detector. So, the shape and type of detector will change according to the type of g-wave being observed.
Fantastic stuff.... Next???
I'm waiting for it ever since I've read his books and the ones about Einstein
Research Complete: Gravitational Waves Theory Confirmed
You have now unlocked Hyperdrive & Gravitational Shield System.
awsome video just nice .....& fabulous
❤❤❤❤❤❤❤❤
Thank you Sir.
As we know that Space has no resistance, why gravitational waves slow down with time/Distance? what makes them slow/Weak?
brian greene is the best
Another awesome presentation from Brian Greene!
What if the world is stretching and contracting like a balloon due to geological phenomena (that we don't know yet), not due to gravitational waves?.
Ideally this should be done in space at three fixed references?
I'm confused!
based on wat ive nderstand, it,s the spacetime that warps not objects like planets etc
+light kira but @1:33, it seems the earth is distorting, it should be, right?. coz if the space is distorting then anything in it should follow it's distortion.
Good point. It may be the unusual expansion of Earth, like a rare earthquake.
it has brought new revolution in science,,,,,,,
thanks for good explantion
great explanation.
This explanation couldn't be better
Wow! That's incredibly briefed. Thanks a lot, sir! :') But, I have only one question, how the gravitational waves squeeze and stretch the planet (Or any astrophysical body in front of it)?
I wish to be immortal, but not for the sake of amassing wealth or anything trivial. I just wanna see how far we can go with scientific breakthroughs. I am so happy to be alive for this one!
"Gravity is nothing but warps in curves in the fabric of spacetime"
Easy way to explain the theory of relativity.
Thanks.
Goes nicely with string theory, does it not? Oscillating gravitons.
Reminds me a great quote over 100 years ago. “If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.”
I have seen no explanation of why we attribute the gravitational wave measured by LIGO specifically to the two colliding black holes. How do we know to link the wave to that phenomenon aside from the massive energy created by the collision?
Einstein and Da Vinci two of the greatest minds who have existed on planet Earth and that will possibly remain so until we reach an extinction event
Nice explanation
I just had one question, from my understanding the gravitational waves from the event bend space and so we've picked up on the waves. How did they determine these were black holes and their sizes. Im not a science major, apologize if this is an ignorant question.
I'm confused, there were a couple of videos of this guy explaining string theory but then they make them private and cannot watch them anymore :/ anyone else?
Interesting, how does that apparatus distinguish between gravitation waves and an earth quake?
Good question. I believe both detectors (Louisiana and Washington) witnessed the same signal by the difference of time needed for gravity waves to travel (I.e., near the speed of light) to reach both detectors. An earthquake would produce two signals in the same way, but earthquake waves don't travel anywhere near the speed of light so the detection time between both detectors would be much, much larger.
I love Brian Greene's enthusiasm! His books are written the same way making science so interesting!
Brian Greene is so good at bringing science to the masses that he should follow in the steps of Carl Sagan with TV documentaries!
It could have been geological. Maybe the constant churning and rotation of the Earth's core produced these extremely minute rhythmic fluctuations on those mirrors. It could have been many other things that produced these extremely minute rhythmic fluctuations on the mirrors.
The tectonic plates constantly grinding against each other?
It could have been something other than "gravitational waves" of a couple of distant black holes revolving around each other gazillion light years away.
Ligo has two detectors so that rules out local disturbances. And the waves are more like fingerprints that fit what was predicted. These are not just a little bump, its way more complex than that.
James01100011 how far apart were the detectors?
YtubeUserr
Livingston, Louisiana and Richland, Washington.. about 1800 miles. But the signature of the vibration is what tells what caused it.
James01100011 Those two detectors are not enough if the rhythmic perturbations on the mirrors were caused by some activity within the Earth's core. Both detectors are on the Earth's surface.
The recorded signature matched a predicted signature closely, yes. Is that conclusive enough for attributing it to gravitational waves caused by black holes/quasars orbiting each other thousands of light years away? I don't think so. This wave signature evidence is not conclusive enough for arriving at such a conclusion.
YtubeUserr
How is the signature not enough?
Love Brian Greene
Hang on a mo... this confirmation is amazing, but, why does the animation show the 'stretching' perpendicular to the direction of compression? One LIGO arm was compressed along its length, the other along its width, ie, the length djd not change. Is this just a case of simplifying?
I don't know much about this setup with the lasers and I apologize in advance if it is already explained but I am only wondering if there is anything else that could potentially disrupt the interference pattern of the lasers or is it 100% certain 2b "gravitational waves"?
In other words, can it be proven that it is indeed gravitational waves and not some other phenomena that is disturbing the interference pattern of the lasers and if so, how?
Absolutely well done and definitely keep it up!!! 👍👍👍👍👍
Warp travel here we come!
I love how you can tell this guy loves what he does!
And what about Gravitational Radio Channel ? Can we use these waves to transfer music ? Information ?
Glad I got this news 1hr after the press.
Thanks for posting this
Cool video, Mr. Greene! Thanks for posting!
I have a question, what would happen if we could put Earth and Moon at rest and add feather on oposite side of Moon, so both could fall on Earth at same time. There shouldbe few possibilities;
1. feather and Moon would fall on Eart at same time,
2. Earth and Moon would exchange gravity fields, feather distance from Earth would first encrease and after it would speed up, because of combined gravity distortion from Earth and Moon.
If anybody know,i would appriciate short explanation.
gr8 explanation !!
An explanation beautiful in its simplicity. Thank you, Professor Greene.
With all due respect,
What happened to ‘The speed of light in a vacuum is the same for all observers,
regardless of the motion of the light source’? As I understand it: Observer ‘A’ at the ‘A’ tube mirror will not be able to measure a change in the distance between the laser and the mirror at any time. From his perspective they are fixed in place. His Tape Measure may expand and contract due to the ripples in spacetime but it will always show the laser to mirror distance to be the same. That's Relativity.
Likewise, one photon will always take the same amount of time to reach the mirror because the distance never changes (from his perspective). Observer ‘A’ will never measure a photon going faster or slower than the known speed of light. Just like his Tape Measure may expand and contract, his wristwatch may speed up or slow down as spacetime fluctuates. This is why the speed of light in a vacuum is constant. That’s the “Time” in “Spacetime”.
Of course this is also true for Observer ‘B’ at the ‘B’ tube mirror. But for Observer
‘C’ at the LIGO detector, who also shares the same perspectives as Observers 'A' & 'B'. Postulate #2 of Einstein’s Special Relativity does not apply. Why is that?
Nice animation & explanation.
Congratulations & great thanks to all scientists at LIGO team.
finally I understand . thanks
Brian gives the best explanations on Einstein theories...and he would make a good Einstein on a biopic. Even now with grey hair.
Big !!!? HUGE thank you for making this
Yes! Thank you brian my friend
How do you exclude the fact that it wasnt the movement of plate tectonics that's making these shifts? There might be error in mesurements..
How can you know it's not just seismic activity that affected these detectors?
1.1 billion dollar bowl of Kool-Aid