Gravitational Waves Discovery – Sixty Symbols


I guess the first thing to say is they’re
a consequence of general relativity that when you get as far as writing down the
equations of general relativity and start trying to solve them you find that some
of the solutions involve these wave solutions. They’re distortions of the spacetime that propagate out.
-I mean they’re important for lots of reasons they’re important
because they are a prediction of general relativity so actually if you then
detect them you’ve found further confirmation that general relativity is actually right.
-Whenever matter passes by through some region of spacetime it will distort the spacetime just like you would distort water when if you
put your fingers through water and waves propagate out this is a propagation of the
spacetime itself, so the spacetime is is sort of moving in and out, propagating out at the speed of light.
-But also because in principle at least they open up an entire new window on the
universe, everything, almost everything we’ve done in astronomy, barring a few cosmic rays
and neutrinos, has been mediated through light – we’ve used light to figure out
what’s going on in the universe. Having an entirely new way of detecting what’s
going on out there in the universe is a very exciting thing for astronomers
because it – it opens up all sorts of new avenues for us to pursue on research. As the Earth goes around the Sun then the spacetime is distorting around the Earth and that’s propagating out in waves in all directions. [Brady off Camera] Do those waves have nothing to do with for example why the moon is attracted to the Earth? [Prof. Copefield] No – no they’re different gravit- that- that’s a different aspect, sometimes we call them gravitational waves, but
they’re different here these are the- the tides don’t exist because of the
nature of gravitational waves propagating. You’ve got the Earth going around the Sun and then you’ve got the Moon going around the Earth. These are very massive objects, right, and
so there’s a net attraction just due to the pure mass of these objects and
that’s where the tides come from the large mass of the Moon and the even
larger mass of the Earth and as they go around the water that’s on the Earth
gets distorted by the changing gravitational field due to the huge mass
of the Moon and the Earth. But on top of that there’s like a
secondary effect going as the Moon is going around it’s causing ripples in
the spacetime and it’s those ripples – these are minuscule ripples that are
propagating out – and it’s those that recently were detected not from the Moon
but from two massive, supermassive – well not supermassive – two massive black holes that
were orbiting each other and so they distorted the spacetime enough that
these waves that propagated out – they could be detected here on Earth.
-I said space is expanding and contracting, but the amount that space is expanding
and contracting by is absolutely minuscule. So this big result that came up
with this thing that they detected – the amount by which space was expanding over the
many kilometers of their detector was less than the diameter of the nucleus of
an atom. So it’s an absolutely tiny – infact that’s why we don’t – sort of notice them going past ’cause if they were big effects, you know you’d see kind of space doing all sorts of weird things. But because they’re so tiny we just don’t see them. It’s just amazing, I mean
the numbers involved, the timing involved – it’s a spectacular event so – a billion light years
away – four hundred and fifty megaparsecs away – So a billion years ago, two black holes which
were each of them thirty times the mass of the Sun, okay? Which is unusual apparently in its
own right to get this kind of combination. They were orbiting, they’d
been orbiting each other for probably millions of years anyway.
-They have to be bound together because they were in orbit around one another and
it’s actually quite complicated because – so the way you get massive black holes is
you have some very massive star exploding in a supernova, and unless that
supernova is set up very carefully, if you imagine you had a pair of binary
stars in orbit around one another – one of them goes supernova – if
you’re not very careful that’s gonna unbind the system because you’ve lost a
whole load of mass, there’s all sorts of energy being transferred between one and the
other – so somehow the two manage to stay bound together, it would seem. When first one went supernova and then a bit later
the other one went supernova – I say a bit later, you know – probably tens to hundreds of thousands
of years later the other one went supernova. Alternatively, possibly, if both of these stars were in a
cluster they might actually have individually been separate stars and
at some point in the subsequent evolution they might have actually got
sufficiently close together that they’d end up capturing each other and end up in a binary
system that way. So it is a little bit of a mystery how you make these two
massive black holes – fairly massive, not supermassive black holes – in orbit around
one another in the first place, but there are at least kind of plausible mechanisms for doing it.
-So they’re doing this for millions and millions of years and then in the
final – I think it’s .2 of a second – first they’re coming closer and closer
together. They start going so rapidly around one another that it begins to
approach the speed of light in fact something like sixty percent of the
speed of light. These are 30 solar mass black holes. As they’re
coming closer and closer, when they’re about, I think, 350 kilometers apart they basically
start merging together. Amazingly, from just looking at the kind
of signal they detect they can learn a great deal about the kind of black holes
it actually was, how the amplitude changes over time, how the frequency of
the signal changes over time. So in this case they’re fairly confident that
one of them was a 29 solar mass black hole and the other one was a 36 solar mass
black hole – they got sort of errors of 1 or 2
solar masses on each one – but they were both 30 to 40
solar mass black holes. So those are the kind of black holes which are probably
the end states of very massive stars, although they are actually on the high
side even for very massive stars. Remember we’ve talked about this intricate
link between the matter and the spacetime. Just imagine – try to imagine – these two huge objects. What they’re doing to the matter, to the spacetime around it, as they- and the spacetime must be going ‘oh my god
what’s happening here’ and it’s flipping up and down, up and down and they’re just
generating – these waves are beginning to propagate out. 350 kilometers, we should find a distance, what, to London? Then you got two 30 solar mass black holes sort of orbiting one
another in this region and so they’re going at close to the speed of light.
So the the spacetime in which it’s revolving must be going – is having huge distortions
associated with it. And so it begins to send out
gravitational waves – they’ve been happening all the time but at a much lower
amplitude because they’ve not been feeling this effect, like this. And then these two black holes keep coming in together and they merge. And what happens is when you’ve got two black holes they’ll merge into a bigger black hole. So one of them is 29 solar masses,
the other one is 36 solar masses. If you add those two together you get 65 solar
masses, so you would think by merging these two together you make a 65 solar mass
black hole. Turns out they can also tell you what the mass of the black hole ended up
with was. Again, just by looking at the kind of signal, and it’s not 65 solar masses, it’s about 62 solar masses. And the reason why is because three solar
masses has disappeared, and via Einstein’s famous formula E=mc^2
those three solar masses of energy have all been turned into the energy of
the gravitational waves. So three solar masses by E=mc^2 has been turned
into a huge amount of energy liberated in this gravitational wave explosion. And in
fact if you work out what the luminosity of the thing was, how bright it was in
gravitational waves, in that fraction of a second as all this happened, it was
brighter, it was liberating more energy, more power than all the stars in the entire observable
universe – for that fraction of a second – all in gravitational waves. But there was no light?
-There may well have been some light as well, but that was just what was coming out in
gravitational waves, mostly the energy of this merger was coming out in these sudden bursts of gravitational waves. They’re traveling now, they’ve got a billion years, they’re traveling in all
directions – they propagate, and then it – as it happens, there’s a detector – two detectors
in America, been recently updated, and they’ve just been turned on – they were doing
I think they call it the engineering run – they haven’t even started doing the proper
science run. They’d been turned on for a few weeks, and a few
billion years later these waves are coming through – now they’ve lost a lot of
their energy, right? Just as light loses its energy and becomes dimmer
and dimmer. The huge amplitude associated with the waves early on is now dimmed down, down, down, down. They pass through this detector, and the detector consists
of two arms – four kilometer long arms. An interferometer, classic interferometer
has two arms to it and you basically shine a light down each arm – usually a laser ’cause you want it to be nice coherent light – and in essence you shine the light backwards and forwards along each of these arms – by recombining the light you can essentially tune the thing so
that the two arms are exactly the same length as each other. And if you set up
your interferometer right, then the light that’s gone down this arm, and the light
that goes down this arm exactly cancel each other out so you end up with no
signal at all. And so that’s a thing called a nulling interferometer it’s set to – you get zero
signal when the two arms are actually tuned in that way. Now, of course, when one
of these waves goes past, in one direction it actually causes a contraction and in
the other direction it actually causes an expansion. “This back and forth stretching
and squeezing happens over and over until the wave has passed.” As the wave
goes past, by this tiny, tiny amount the arms will no longer be exactly the
same length – and the effect of that is then that exact cancellation ceases to
work, and suddenly some of the light gets through your interferometer. So the way they
actually detect it is that they actually start seeing light in the interferometer
because the arms have changed in length by that tiny amount.
-This huge amount of energy required this desperately accurate detector in order
to be able to find the gravitational waves. And then you might ask: “How do you
know you’ve found gravitational waves, surely everything distorts?” [Brady off Camera] Seems like an
instrument that a mosquito sneezing would effect them. [Proffessor] And they get huge numbers of
false positive detections, so any kind of earth tremor, a truck driving by, all those kinds
of things produce signals that they end up detecting in these interferometers. There’s
two things that save them: one is that actually it has – the things that you’re
looking for – so things like these black hole signatures – have a very
characteristic shape to them that the way that the oscillations increase and
decrease in amplitude with time – has this very classic signature to it that tells you
the kind of thing you’re looking for – so they know what sort of thing to look for,
and then the second thing that saved them is that there isn’t just one
interferometer, there’s two working at the same time a large distance apart from
one another – and so the chances of the same
pathological truck going past both of them at the same time producing
something that looks exactly like a black hole merger signature is at that point astronomically small – so they can,
by doing this kind of coincidence thing of detecting it in both detectors
almost simultaneously – tells them that actually they have detected a real
astrophysical result. One of the upsides to actually having two detectors; if the
gravitational wave is coming from over here somewhere – it’ll hit one detector
first and then a bit later it’ll hit the other detector So the wave came through, hit
Louisiana first, and then the light travel time – because they’re going
at the speed of light – it then passed through the Washington detector – exactly
the same profile – 7 milliseconds later which corresponds
to the light travel time – and that enabled them to sort of give an estimate of
where in the sky this original thing had started from. So for example this
thing that they’ve detected, they know it’s somewhere in the southern hemisphere.
They can’t say much more than that, it’s somewhere in the southern sky, is about
as close as they can get – but they do at least get some directional information.
When they start getting third and fourth detectors up obviously that will give them more
information, so they’ll actually be able to triangulate much more exactly where these sources are.
-Potentially an issue for the gravitational wave
community: it could be that we’re on the verge of being inundated now with black hole by neutron star.. black hole binaries.. So all of a sudden they’re everywhere
and we just hadn’t had the sensitivity to detect them and now *poof*. No one really
knows how many there are out there because all that we have to
work on are theories where you estimate how many you expect there to be – so that, I was reading that, you know, they’re expecting an order of 40 per year, but hey, we may have got that wrong, it may be
four thousand or something, in which case you have a bit of a different issue – you have like an LHC issue, where you’ve got so many collisions. How are you gonna extract out
the interesting physics here, you know, where’s the Higgs coming from – here you
might just have so much radiation coming – gravitational waves coming in from all of
these binary systems that we think we understand the binary systems and we’re
now interested in finding the the weird and wonderful early universe features. That might be a – Well that’ll be a nice problem to have, I think. You’ve got two very massive objects and they’re in orbit around each other in a binary black hole system when something is moving around in a circular orbit it’s actually accelerating So they weren’t looking. They were in their shut down mode when this gravitational wave when this gravitational wave passed through it. Travels for a billion years, those detectors were up and running maybe a few months earlier, but they had just shut down and it passed through. [Brady off Camera] Blink and you’ll miss it [Professor] blink and you miss it

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100 thoughts on “Gravitational Waves Discovery – Sixty Symbols

  1. Imagine how what we could do if we could've harnessed the power of when they collided, that would be amazing!

  2. Can gravitational waves propagate faster than the speed of light as they are just formations in space time?

  3. You guys are losing my respect, and to those of whom i associate with. You need to forget gravitational waves, and start to think more about electromagnetism, you know, that thing not considered until 150 years after newtons gravitional theories…? You can't completely explain reality or physics without mentioning electromagnetism, magnetic fields or electrical charge, not in the 21st century it doesn't make sense.

  4. Can you guys do a video explaining why solar systems and galaxies tend to occur in planar orbits. Considering all the different orientations an orbit could take. Why the disk shape?

  5. Hi, I have a question about the solar system, and I was wondering if any of you knowledgeable people know the answer. So all of the planets orbit the sun on basically the same plane, or at least that's how it always is in diagrams and models, is there any gravitational reason for this, or is it just some kind of coincidence?

  6. Prof. Merrifield mentioned that 3 solar masses were radiated away in gravitational waves. Is the earth losing mass as it generates smaller gravitational waves traveling around the sun?

  7. 9:12– So the light is able to cause the sources of the light to move? I didn't get that part- I mean light doesn't have that much of energy!

  8. nothing can escape a black hole?? nope,, gravitational waves can…
    why is light not able to escape but gravitational waves are?

  9. The sheer enormity of it all is mind boggling. ~30 solar mass objects moving at 60% light speed, emitting 3 solar masses worth of energy faster than a human can blink. Wow.

  10. I ask a question, but apologise for not being adept at the mathematics required to answer it:

    Where gravity is distorting time/space, and the G-wave is a perturbation in time/space that propagates from the event that causes it, my question is this: When a distortion in time/space goes through the arms of the LIGOs, is the light beam also being effected by an equivalent blue/red shift that corresponds to the distortion of the lengths of the arms?

    The consequences of this is that the nullifying light beams would still be in phase no matter how large the amplitude of the G-wave was.

  11. what happened to the merged black hole, it remained static or is it moving across space due to the collision?

  12. K, I'm not gay, but….
    (lmao)

    I'm absolutely in love with Prof. Ed Copeland

    ..I could listen to him talk all day

    ..not to disparage the other professors, they're all amazingly awesome ..love 'em

    and of course the journalistic wunderkind Brady ; P

  13. I love the passion these men have for science. You can fake a smile, even intellect. But a passion of that level is nearly beyond finite to replicate.

  14. I don't understand how the detector works. So, the gravitational waves deform the arms of the detectors by making them shorter or longer? Then why is the calibration laser not also stretched or contracted in the same amount? Why is the laser not affected by the variations of the space time?

  15. Do these waves dissipate over time-space?
    Are the amplitudes of the waves felt here lesser than the ones felt right next to the event?
    8:05 thank you
    How…where do they dissipate to? WHAT dissipates them, other bodies?
    Do these waves have a mechanical or electromagnetic behavior? i'd guess mechanical, given their gravitational origin…but they travel at the speed of light?!
    No, i just read about it on wikipedia, i can't just tackle this with classical mechanics or continuum mechanics, and i don't know general relativity (probably never will at my field of study).
    I can only wonder how it feels to discover such…discovery 😀
    Cheers to the teachers, they look super excited about it.

  16. in the double slit experiment does the distance between the slits make a difference? every example ive seen they are close together, what would be the result if they are 10 feet apart?

  17. Amazing! Can a genius breakdown for all viewers why in a UNiverse that is expanding and creating more "intermatter" space, gravity is doing opposite? Why is gravity clumping matter into stars, planets, galaxies, creating energy thereby and more diverse atoms and possibly life in a few places? I mean is there a mathematical equation that can establish a pattern betwixt these two opposing forces?

  18. was the mass of the moon put in question by the ringing it demonstrated after being impacted

  19. Thank you everyone who participated in this video, for the time and work put into it, and thank you for SHARING this with us 🙂

  20. So we were so lucky we saw two black holes from a binary system merge together? I'm sure it's not exactly an everyday thing

  21. I love the sheer scale of the event. A neutron star is a colossal, hard to imagine, event. This is so huge in comparison. I got a better idea of the scale from this video. Thanks.

  22. One of the best mini-dissertations on gravity waves I have seen!  But Brady – I have a request which may sound a bit silly – but here it is anyway:  Will you do a video of Ed Copeland walking through and trying to explain some of the equations we always see behind his head on his chalk board?  I do not believe anyone is able to understand them or what they imply.  If Ed does, please have him tell us mere mortals what the equations mean or imply.  Thank you!

  23. The graphics are incorrect. The waves are drawn with pretty short wavelength, but it cannot be shorter than the orbit's half-circumference. More than that, the wavelength near to the system is a bit shorter, than the wavelength farther away, because of time dilation. The rotation period we observe in a few last moments is longer than a local observer would see.

  24. Anyone can train their vision to see the very subtle ebb and flow of spacetime all around us, but it requires a clear and open mind. This is the same kind of perception as the "breathing walls" effect often experienced under the influence of psychostimulants like LSD and Psilocybin, which amplify conscious wareness of subtle patterns such as these by lowering synaptic firing thresholds of neurons in the primary visual cortex. Normally we are too busy getting on with our lives to have any awareness of anything that doesn't immediately stand out in our environment, but all it takes is a few minutes a day to simply sit quietly and look around at your world without filtering out all the beauty and wonder of it all. You might be surprised at all the things you have never seen, despite having been looking right at them all along.

  25. It's fucking hilarious how unthinkably ridiculous this is: .2 seconds till merging, 60% light speed, 350 km, a billion years ago, quadrillions of miles away, spacetime warping on the scale of atomic nuclei, more energy in gravitational waves than all stars in the universe…

  26. so if one gramm of mass would be converted in to 21,5 kilotons of energy
    I wonder how much would be 3 masses of the sun

  27. how person would feel standing at safe distance of let's say few light years. far enough not to be evaporated by the released energy but close enough to feel it?

  28. some questions, How gravity escape from the distortion of space time from a BH, and if the space time can act like a field wouldn't have a particle associate with it?

  29. Citing spinning black hole binaries as a source for gravitational waves is the same as mistaking a spinning emergency vehicle lamp and reflector for being a blinking light. The "waves" as they interpret them are only generated by the spin of massive black holes, where the gravity is more intense in one or two directions than it is in the directions between them. What I'd like to see is finding "gravitational waves" in relatively static mass. But if the masses are static, or at least not spinning in such a way then there's no wave. I think it's a mistake to call it a wave at all.

  30. "This huge amount of energy required this desperately accurate detector in order to be able to find the gravitational waves." 9:30 Hearing Dr. Copeland laugh at how incredible the science is makes my heart sing.

  31. seems like gravitational waves are a gravitational equivelent of a nuclear explosion. instead of 2 atoms fusing and losing mass releasing a huge amount of energy it's 2 black holes fusing, losing mass and releasing a huge amount of energy

  32. Do gravitational waves only lose amplitude due the increasing surface of the propagating sphere, or is there an additional attenuation?

  33. okay… more energy released than all the rest of the observable universe in that instant.
    can someone lend me some gas money?

  34. Does (did) the combination of the two massive black holes into one massive black hole make gravitational waves in a sphere (three dimensions)?

  35. if the change in distance was something smaller than the nucleus of an atom, like very small, how do we know that it can't be accounted for in the motion of the earths crust?

    edit: oh… they answered my question at about 10mins in.

  36. I have a question regarding the unification
    of gravity with quantum mechanics.

    I am sure that someone has thought of this
    before and debunked it. I have asked some of my friends who are teachers but
    none of them could answer my question. Gravity and acceleration are both very
    similar and if you were in a box and you felt an acceleration you wouldn’t be
    able to tell whether that was through gravity or another force causing you to
    move.

    What if rather than bending space time
    large mass bodies cause space-time to flow toward and around them rather like a
    liquid. So that planets are not orbiting because of the pull of this force we
    call gravity, rather they are moving in a current of space-time. In the same
    way that a mote of dust may move around a plug hole when the bath empties. It’s
    not moving itself, rather the medium it is sitting in is moving. Taking this
    further, if space-time can be quantised like light into discrete portions,
    then the reason why we don’t see gravity affects at the microscopic level could
    be because particles are so small that they all exist on one quanta of
    space-time at and are all subject to the same gravity moving together like
    travelers on a boat.

    I would be really grateful if someone could
    find the time to answer my question. I apologies in advance for my tenuous
    grasp of the complicated physics involved.

  37. Does space have elastic behavior? If a large object would suddenly disappear, would the curvature of space just get flat in the speed of light, or would it vibrate due to its elasticity, maybe even get negative curvature before it evens out?

  38. I'm glad the question of false positives was addressed. My first thought was how could it work with thermal expansion, tides, and tremors constantly upsetting the detector.

  39. Is it true that String Theory kind of suggests that gravitational waves should not have been found? Just wondering if this result has had any impact on String Theory?

  40. Wait – so how much would you actually distort if you were RIGHT next to the black holes as they collided? Would it be lethal? Would you notice?

  41. "They can tell you what the mass of the black hole ended with was. Again, just by looking at the kind of signal, and it's not 65 solar masses, it's about 62 solar masses." How can they do this? What are they comparing it to? It's like saying you can tell me the temperature of a thermometer that doesn't have any visible scale on it. Someone please help me understand what are they comparing this with?

  42. If we were to be sufficiently close to an event that causes gravitational waves at an amplitude of say 1 cm, would it destroy us? I visualize these waves travelling through space, as gravitation interacts with matter weakly, would the strain on matter for such a wave be high?

  43. Hey, if the speed of light is 29979458, then what is the wavelength of this gravity wave?

  44. In reference to this signal( gravitational wave) here is something to consider LIGO False positive, problem is that the methods used to interpret the noise (which has a smaller amplitude than the atomic nuclei) they use predetermined template comparator that introduce a bias in these observations, Which requires a inordinate amount of data processor or data comparison in Searching for the predetermined signature of a chirps, which begins with a low and moves to a higher frequency may also be the characteristics of other natural phenomena Not related to gravity. There is also another problem, and at is, to associate the Signal (chirps) with cosmic events; There are three natural relationships: similarity, contiguity and cause and effect. Of these, the causes and effects it is the most problematic where the narrative does not have a connecting principle, but instead it is artificially juxtaposed by the mind and not real. In other words, how many of these events could be associated artificially and are not real. How many of these events occur in the Universe and are accidentally and wrongly associated. This is a problem that has not been answered beyond a shadow of a doubt. This is a prediction; they will find these phenomena Very common and they’re not related to black holes. It Is going to be the biggest debacle in Scientific history! Similar to the epicycles of the past.

  45. So now they invent how to harnest gravity waves , does it affect timecrystals ? Did anyone notice the wave as physical effect/sensation , at the moment it should have happened ..maybe – I know I know someting happened with the tiny earthquakes we have in Sweden when they occur ,Im not even close to them.

  46. This guy is saying that the total mass of these 2 objects was 65M☉ and converted 3M☉ into energy while merging just by moving though spacetime. That means that they converted a combined total of nearly 5% of their mass into energy just by moving though spacetime.

    So my question is, why doesn't the planet earth lose 5% of it't mass while moving though spacetime ?

  47. 0:45 These aren't the gravity waves predicted by Einstein and his Theory of Relavity, these gravitational tides are described by classical physics (Newtonian Mechanics )

  48. What is an electron hole? Described and accepted as a charge carrier in solid crystaline lattice. It's accepted as fact yet we don't know hat it is. Could it be a micro black hole? We know light as a wave and a particle. I'm making a huge jump here but could these "electron holes" create gravitational waves, instead of light waves?

  49. Mass is not the cause of gravity. Its the reactant to space/time. Celestial bodies absorbs and re-emmit the space/time " particles " that they gather. Absorbtion is gravity while emission is magnetism. Saying that mass cause gravity is the same thing as saying: the sail of a sailboat is what makes it go forward. If you go beyond that, there's wind as the cause. Sail is the reactant to the wind. Trans-dimensional light is the key to understanding gravity. This light comes from stars. In a way, our sun "create" our local space time. It is our reality projector.

  50. one tide towards the moon is pulled up by the moon's gravity. the reason for the tide heap on the side away from the moon is because the earth is being pulled towards the moon, thus inertia causes it to be left behind is it follows the moon. So both are in orbit around each other, and the water and earth responds to both the gravity gradient, and the inertia of the earth following towards the moon heaping up both sides. it is the gravity gradient and inertia son.

  51. Anyone who talks about space/time moving does not know what he is talking about. If you replace time with the forth dimension and call it space/time then nothing moves because you need another dimension (time) to create movement.

  52. 👽Sweet talk, I think Gyroscopic force has something to do with Frame dragging that we don't yet understand.👽 Excuse the use of the word force.

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