We'll have all sorts of crazy signals. And you'd be a damned fool if you didn't look for things you weren't expecting, because that's probably what you're going to see first.
— Rainer Weiss
Observing gravitational waves would yield an enormous amount of information about the phenomena of strong-field gravity. If we could detect black holes collide, that would be amazing.
Every time you accelerate - say by jumping up and down - you're generating gravitational waves.
The students on my course were fascinated by the idea that gravitational waves might exist. I didn't know much about them at all, and for the life of me, I could not understand how a bar interacts with a gravitational wave.
A gravitational wave is a very slight stretching in one dimension. If there's a gravitational wave traveling towards you, you get a stretch in the dimension that's perpendicular to the direction it's moving. And then perpendicular to that first stretch, you have a compression along the other dimension.
The triumph is that the waveform we measure is very well represented by solutions of these equations. Einstein is right in a regime where his theory has never been tested before.
We're going to be seeing things from regions in the universe where Einstein is the whole story. Newton you can forget about.
All of this technology wasn't available to Einstein. I bet he would've invented LIGO.
By the time we made the discovery in 2015, the National Science Foundation had put close to $1.1 billion into it.
The field equations and the whole history of general relativity have been complicated.
Einstein had looked at the numbers and dimensions that went into his equations for gravitational waves and said, essentially, 'This is so tiny that it will never have any influence on anything, and nobody can measure it.' And when you think about the times and the technology in 1916, he was probably right.
It's very, very exciting that it worked out in the end that we are actually detecting things and actually adding to the knowledge, through gravitational waves, of what goes on in the universe.
We expect surprises. There has to be surprises.
One of the things I sort of dreamt about awhile ago is that if Einstein were still alive, it would be absolutely wonderful to go to him and tell him about the discovery, and he would have been very pleased, I'm sure of that.
We've seen black holes, which is already wonderful. We also expect to see the merger of neutron stars, and that was a thing that actually gave this field a certain credibility when it was discovered that there were pairs of neutron stars in our galaxy, and people stopped laughing at us when that was found out.
We are all enormously indebted to the National Science Foundation of the United States and the American public for steady support over close to 50 years.
The waves travel with the velocity of light and slightly squeeze and stretch space transverse to the direction of their motion. The first waves we measured came from the collision of two black holes each about 30 times the mass of our sun.
Over and over in the history of astronomy, a new instrument finds things we never expected to see.
The rule has been that when one opens a new channel to the universe, there is usually a surprise in it. Why should the gravitational channel be deprived of this?
If the wave is getting bigger, it causes the time to grow a little bit. If the wave is trying to contract, it reduces it a little bit. So, you can see this oscillation in time on the clock.
Many of us on the project were thinking if we ever saw a gravitational wave, it'd be an itsy bitsy little tiny thing; we'd never see it. This thing was so big that you didn't have to do much to see it.
The whole idea of gravity curling up space, that is the epitome of what is going on in a black hole. I would've loved to have seen Einstein's face if he were presented with the data that we actually discovered such a thing, because he himself probably didn't believe in much of it.
It's a spectacular signal. It's a signal many of us have wanted to observe since the time LIGO was proposed. It shows the dynamics of objects in the strongest gravitational fields imaginable, a domain where Newton's gravity doesn't work at all, and one needs the fully non-linear Einstein field equations to explain the phenomena.
We haven't found anything that we can't explain at all. I hope that will happen.
Over years, the noise level will be brought down, and LIGO will be three times better and see three times farther.
We were looking almost one-tenth of the way to the edge of the universe. We're planning to use the facilities we have to make improvements by another factor of 10... a strain sensitivity that is 10 times smaller. This means looking 10 times further out into the universe.
All at once, funding was gone due to the Mansfield Amendment, which was a reaction to the Vietnam War. In the minds of the local RLE administrators, research in gravitation and cosmology was not in the military's interest, and support was given to solid-state physics, which was deemed more relevant.
We knew about black holes in other ways, and we knew about neutron stars - well, those are the two things that ultimately got seen.
By the time 1967 had rolled around, general relativity had been relegated to mathematics departments... in most people's minds, it bore no relation to physics. And that was mostly because experiments to prove it were so hard to do - all these effects that Einstein's theory had predicted were infinitesimally small.
You think Earth's gravity is really something when you're climbing the stairs. But, as far as physics goes, it is a pipsqueak, infinitesimal, tiny little effect.
Why do you do science? In this particular case, we don't have a very good reason to be doing this except for the knowledge that it brings. This research is especially important to young people. We all want to know what's going on in the universe.
We know about black holes and neutron stars, but we hope there are other phenomena we can see because of the gravitational waves they emit.
What was done is measure directly, with exquisitely sensitive instruments, gravitational waves predicted about 100 years ago by Albert Einstein. These waves are a new way to study the universe and are expected to have significant impact on astronomy and astrophysics in the years ahead.
I prefer really often to talk to high school students, mostly because I think they're the future for us.
When we initially proposed LIGO, the only sources that we were really contemplating were supernovae. We thought we would see something like one a year, maybe even ten a year.
The waves from all the different parts of a sphere would cancel each other out. You need motion that's nonspherical.
I said, suppose you take a light - I was thinking of just light bulbs because, in those days, lasers were not yet really there - and sent a light pulse between two masses. Then you do the same when there's a gravitational wave. Lo and behold, you see that the time it takes light to go from one mass to the other changes because of the wave.
Space is much stiffer than you imagine; it's stiffer than a gigantic piece of iron. That's why it's taken so damned long to detect gravitational waves: to deform space takes an enormous amount of energy, and there are only so many things that have enough.
This is the first real evidence that we've seen now of high gravitational field strengths: monstrous things like stars moving at the velocity of light, smashing into each other, and making the geometry of space-time turn into some sort of washing machine.
The concept of what we're looking for is so important. The fact that the effect is tiny is just our misfortune.
Receiving money for something that was a pleasure to begin with is a little outrageous.
Gravitational waves, because they are so imperturbable - they go through everything - they will tell you the most information you can get about the earliest instants that go on in the universe.
I didn't understand the Weber bar and how gravitational waves interacted with it. I sat and thought about it over a weekend, trying to prepare for the lecture for the following Monday. I asked myself how would I do it. The simplest way... was a thought experiment.
The obvious thing to me was, let's take freely floating masses in space and measure the time it takes light to travel between them. The presence of a gravitational wave would change that time. Using the time difference, one could measure the amplitude of the wave.
Most of us fully expect that we're going to learn things we didn't know about.
There was a person who thought I was OK. I wasn't a complete dope. I got some confidence out of that.
The fact that this radiation is so penetrating - nothing stops it - makes it so you can look for things that you have never seen before, and you can look at things you know in a way that's new. That is really the big step forward.
Experimentally, we now have demonstrated that Einstein's theory is right in strong gravitational fields. That's important to a lot of people.
We live in an epoch where rational reasoning associated with evidence isn't universally accepted and is, in fact, in jeopardy. That worries me a lot.
For reasons probably related to the popular vision of Albert Einstein and, also, the threat posed by black holes in comic books and science fiction, our gravitational wave discoveries have had an amazing public impact.
