YouSaid · the spoken record

Barry Barish

lines on the record: 160
first: 2021-08-23
most recent: 2021-08-23
sittings or episodes: 1
sources: podcast

Every line below is reproduced as it was said and linked to the record it came from. Nothing here is summarised or generated. Directory · Search · Corrections

“So you're seeing much, much more of the universe. The big change is that if you can see far out, you see further back in history.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, so let me talk to both the instrument and the science, they go hand in hand. I mean, the thing that I said is if we make it better. We see more kinds of weaker objects, and we do astronomy, okay? We're very motivated to make a new instrument. Which will be a big step, the next step, like making a new kind of telescope or something. And the ideas of what that instrument should be haven't converged yet. There's different ideas in Europe. They've done more work to kind of But I think over the next few years we'll develop those. The idea is to make an instrument that's at least 10 times better than what we have with this instrument 10 times better than that. 10 times better means you can look 10 times further out. Times further out is a thousand times more volume”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Singling out people, I mean, on the other side of it, singling out people has all kinds of, you know, whether it's for Academy Awards or for this, have unfairness and arbitrariness and so forth and so on. So that's the other side of the coin.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Okay, and at best, they may have an eight or something that knows a little science. So our country is, and all countries are hardly. Hardly take into account science in making decisions. Okay, and Having a Nobel Prize People in those positions actually listen. So you have more influence. I don't care whether it's about global warming or what the issue is. There's some influence which is lacking otherwise. And people pay attention to what I say if I talk about global warming. They wouldn't have before I had the Nobel Prize.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, it has a little bit more. One thing I didn't expect, which is good, is that, you know, we have a government. I'm not picking on ours necessarily, but it's true of all governments are not run by scientists. In our case, it's run by... Lawyers and businessmen.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Celebrate science for several days, different fields, chemistry, medicine, and so forth. And everybody doesn't understand everything about these. They're generally fairly abstract. But then it's on the front page of newspapers around the world. So it's really good for science. It's not easy to get science on the front page of the New York Times. It's not there should be, but it's not. And so the Nobel Prize is important in that way. Otherwise, you know, I have a certain celebrity that I didn't have before.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, that's a complicated question. As a physicist, it's something if you're trying to win a Nobel Prize, forget it because they give one a year. So there's been 200 physicists who have won the Nobel Prize since 1900. And so that's the, and so things just have to fall right. So your goal cannot be to win a well prize. It wasn't my dream. It's tremendous for science. I mean, why the Nobel Prize for a guy that made dynamite and stuff is, you know, what it is. It's a long story, but it's the one day a year where actually the science that people have done is all over the world and so forth. Forget about the people again, you know, it is really good for science.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“That was the birth of not just using your eyes to understand what's out there. And since that time, we've made better and better telescopes, obviously, and astronomy thrives. And in a similar way, we're starting to be able to Crawl, but we're starting to be able to do that with gravitational waves. And it's going to be more and more that we can. Do is we can make better and better instruments because, as I say, it's not limited by. Picking it out of others. Yeah, it's not limited by the physics. So you have an optim”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Of physics. You can't make the physics go away. It's there. In our case, we have a very weak signal, but once we get good enough to see it, it's weak compared to where we've reduced the background. But the background is not physics. It's just technology. You know, it's getting ourselves better isolated from the Earth or getting a more powerful laser. And so since 2015 when we saw the first one, we continually can make improvements that are enabling us to turn this into a real science to do astronomy, a new kind of astronomy. It's a little like astronomy. Galileo started. I mean, he basically took lenses that were made for classes and he didn't invent the first telescope, but made a telescope. At Neptune and saw that it had four moons.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Was never understood until there was a theory of it about 70 years ago now. And so they discovered it's named after a man named Higgs. It's called the Higgs boson. And so it was discovered. But since that time, and I worked on those experiments since that time, they haven't been able to progress very much further, a little bit, but not a lot further. And the difference is that we're really lucky. We're in what we're doing in that there, you see this Higgs boson, but there's tremendous amount of other physics that goes on and you have to pick out the needle and the haystack kind of.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“A really important discovery that was made before ours was what's called the Higgs boson made on the big accelerator at CERN. You know, this huge accelerator, they discovered a really important thing. It's, you know, we have Einstein's equation E equals MC squared. So energy makes mass or mass can make energy and that's the bomb. But the mechanism by which that happens, not vision, but how do you create mass from energy?”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, yeah, we've. We now we're off because of the pandemic, but when we turned off, we were seeing some sort of gravitational wave event each week. Now we're fixing. We're adding features where it'll probably be when we turn back on next year it'll probably be one every couple days. They're not all the same, so it's learning about what's out there in gravity instead of just optics. So it's all great. We're only limited by. The fantastic thing other than that is a great field and it's all new and so forth is that experimentally the great thing is that we're limited by Technology and technical limitations, not by science. So”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Within a month, we convinced ourselves. We kept a thousand collaborators quiet during that time. Then we spent another Month or so trying to understand what we'd seen. So that we could do the science with it instead of just putting it out to the world and let somebody else understand that it was two black holes and what it was.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“But you don't want to fool yourself. So we had been a scientist. We had a, for me, we had to go through and try to understand that the instrument itself, which was new, I said we had rebuilt it, couldn't somehow generate things that looked like this. That took some tests. And then the second you'll appreciate more. We had to somehow convince ourselves we weren't hacked in some clever way.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“And then you were like, so as human beings, we all have different reactions to almost anything. And so quite a few of my colleagues had a eureka moment immediately. I mean, the... The figure that we put in our paper. First is just data. We didn't have to go through fancy computer programs to do anything. And we show next to it the calculations of Einstein's equations. It looks just like what we detected. And we did it in two different detectors halfway across the US. So it was pretty convincing.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Fortunately, got the National Science Foundation to give us another couple hundred million dollars or a hundred million more. And we rebuilt it or fixed or improved it. And then in 2015, we turned it on. And we almost instantly saw this first collision of two black holes. And then we went through a process of do we believe what we've seen?”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Stick to technologies that we had at least enough knowledge that we could make work or had tested in our own laboratories. And so then we put together the instrument, we made it work, it didn't work very well, but it worked, and we didn't see any gravitational waves. Then we figured out what limited us and we went through this every year for Almost ten years, never seeing gravitational waves, we would. Run it looking for gravitational waves for months. Learn what limited us, fix it for months, and then run it again. Eventually we knew we had to take another big step, and that's when we made several changes, including adding these active seismic isolation, which turned out to be a key. And we.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“You build on your failures. That's expected. So we're trying things that no one's done before. So technically not just gravitational waves. It's built on failures. But anyway, we did. Before me, even the people did R&D on the concepts. But starting in 1994, we got money from the National Science Foundation to build this thing. It took about five years to build it. So by 1999, we had built the basic unit. It did not have active seismic isolation at that stage. It didn't have some other things that we have now. What we did at the beginning was”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“And they had the thing that they were working together on a kind of object that they wouldn't have otherwise and were part of a bigger team where they could discover something that isn't even engineers. These are engineers that do lasers and they're part of our laser physicists.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“The human problem is always the hardest. And so that's an art, not a science, I think. I think the fact here that Combined, there's a romantic goal that we had to do something that people hadn't done before, which was. Important scientifically and a huge challenge enabled us to say and get, I mean, what we did just to take an example, we used the light to go in this thing comes from lasers. Need a certain kind of laser. So the kind of laser that we used, there were three different Institutions in the world that had the experts that do this, maybe in competition with each other. So we got all three to join together and work with us to work on this as an example”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“You realize that somehow the team is able to do more than the individuals could do themselves than they buy on, kind of, in terms of the process. So that's the goal that you have to. Have is to achieve that. And that means that you have to realize parts of what you're trying to do that require not that one person couldn't do it. It requires the combined talents to be able to do something that neither of them could do themselves. And we have a lot of that kind of thing. And I think, I mean, build into some of the examples that I gave you. And so how do you then? So the key almost in anything you do is the people themselves, right? So in our case, the first and most important was to attract, to spend years of their life on this, the best possible people in the world to do it. So the only way to convince them is that somehow it's”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Okay, I think the general idea is one we all know. You want to get where the sum of something is more than the individual parts is what we say, right? So that's what you're trying to achieve. Okay, how do you do that actually? Mostly, if we take multiple objects or people, I mean, you put them together, the sum is less than. Why? Because they overlap. You don't have individual things that this person does that, this person does that, then you get exactly the sum. But what you want is to develop where you get more than what the individual contributions are. We know that's very common. People use that expression everywhere. And it's the expression that has to be kind of built into how people feel it's working. Because if you're part of a team,”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“But another concept lost in this, you just said you started talking about single cell. If they realize this discovery that we made that everybody spot off on happened one point three billion years ago, Somewhere And then the signal came to us 1.3 billion years ago, we were just converting on the Earth from single cell to multi-cell life. So when this actually happened, this collision of two black holes. We weren't here, we weren't even close to being. We”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, there's a unit. High vacuum is when the vacuum and the units that are used, which are tors, or it's 10 to the minus 9. And there's high vacuum, it's usually used in small places. The biggest vacuum system. Is that CERN in this big particle accelerator, but the high vacuum where they need really good vacuum so particles don't scatter in it is smaller than ours. So ours is a really large Vacuum system.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, we can measure how good the vacuum is. So we can know that, but there are a leak can develop, and then we don't, how do we fix it, or how do we find it”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“But to make it, we started with A role of stainless steel, and then we roll it out like a spiral so that there's a spiral weld on it. Okay, so the engineering was fine. We did that. We worked through a very good company and so forth to build it. But the big worry was, what if you develop a leak? Is a high vacuum, not just vacuum system. Typically, in a laboratory, if there's a leak, you put helium around the vacuum. The thing you have, and then you detect where the helium is coming in. But if you have something as big as this, you can't surround it with helium.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Anything like that, I think the one that My colleague at MIT, Ray Weiss, worked on so hard and was much more of a worry than this. This is only a question if you don't do it well enough. You have to keep making it better somehow. But this whole huge instrument has to be in vacu And the vacuum tanks are this big around. And so it's the world's biggest high vacuum system. So how do you make it, first of all? How do you make this four meter long sealed vacuum system? It has to be made out of.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, for parts of it, for the active canceling, we worked for the instruments, for the sensor and instruments. We worked A small company near where you are because it was our MIT people that got them that were interested in the problem because they thought they might be able to commercialize it for making stable tables to make microelectronics, for example, which are limited by how stable the table is. At this point, it's a little expensive.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“This is possible. Yeah, and larger scale. We made test. That also has to be in vacuum, too, but we made test chambers that had this system in it, our first mock of this system, so we could test it. And optimize it and make it work. But it's just a mechanical engineering problem.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Oh, I did. I didn't know that we needed for sure that we needed active when we started. We did dispassive, but we were doing the Test to develop the active to add as a second stage, which we ended up needing. But there was a lot of now there was a lot of skepticism, a lot of us, especially astronomers, felt that money was being wasted, as we were also expensive doing what I told you is not cheap. It was kind of controversial. It was funded by the National Science Foundation.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“It is. And so it took a long time. And I think nobody seems to challenge the statement that this is the most precision, precise instrument it's ever been built, LIGO.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“What gets through us is one part in 10 to the 12th. That's a pretty big reduction. You don't need that in your car, but that's what we do. And so that's how Iolated we are from the Earth. And that was the biggest, I'd say technical problem outside of the physics instrument, the interferometer.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“We have to see measure not just the engines still made noise, but the earth is shaking, it's moving in some direction. So we have to actually tell not only that there's noise and cancel it, but what direction it's from. So we put this array of seismometers inside this array of shock absorbers and measure the residual motion and its direction. And we put little actuators that push back against it and cancel it.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Noise canceling. So, how do they work? They basically you go on an airplane and they sense the ambient noise from the engines and cancel it because it's just the same over and over again. They cancel it. And when the stewardess comes and asks you whether you want coffee or tea or drink or something, you hear her fine because she's not ambient. She's a signal.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“We didn't just we weren't good enough to discover gravitational waves. So we did another, we added another feature. And it's something else that you're Aware of probably have one. And that is to get rid of noise. You've probably noise, which is you don't like. And that's the same principle that's in these little Bose earph”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Shockup's over Okay. And this is now experimental physics at its limit. Okay, so you do this and we make the world's fanciest shock absorber. It's just mechanical engineering.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“What they do is they take the thing that went like that and they basically can't get rid of the energy, but they move it to very, very low frequency. So what you feel is... You feel like, oh, shh. Smoothly, okay? All right, so We also work at this frequency, so if we basically, why do we have to do anything other than shock absorbers? So we made the world's fanciest shock absorbers. Okay, not just like in your car where there's one layer of them. They're just the right squishiness and so forth. They're better than what's in the cars. And we have four layers of it. So whatever shakes and gets through the first layer, we treat it in a second, third, fourth layer.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“The same frequency that's where the earth is acquired is. So we have to work in that frequency. So we're not looking at all frequencies. So the solution for the shaking of the earth to get rid of it is pretty mundane. If we do the same thing that you do to make your car drive smoothly down the road. So what happens when your car goes over a bump? Early cars did that. They bounced. Okay, but you don't feel that in your car. So what happened to that energy? You can't just disappear energy. So we have these things called shock absorbers in the car.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“That's right. So if you go to You go to 1 hertz instead of 10 hertz, the earth is really moving around. So, somehow we live in what we call the audio band. Tens of hertz to thousands of hertz. That's where we live. That's where we live, okay If we're going to do an experiment on the earth”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“We know by evolution. Our bodies know. It's the audio band. The reason our ears work where they work is that's where the earth isn't going making too much noise.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“This is actually an easier problem. You just have to do it really well. So making a clean room is really a tough problem because you have to put a room inside a room. This is really simple engineering, our physics. Okay, so what do you have to do? How do you isolate yourself from the earth? First we work at we're not looking at all frequencies for gravitational waves, we're looking at particular frequencies that you can deal with here on Earth. So what are frequencies would those be? We were just talking about frequencies.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“But it's moving all the time. So somehow it's moving so much that we can't deal with it. We happen to be trying to do the experiment here on Earth, but we can't deal with it. So we have to make the instrument isolated from the Earth The frequencies we're at, we've got to float it. That's a mechanical, that's an engineering problem, not a physics problem.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“So it's just code. So I'll give you an example of doing mechanical engineering. At a basically mechanical engineering and geology and maybe at a level. So what's the problem? The problem is the following that I've given you this picture of an instrument by some magic I can make good enough to measure this very short distance. But then I put it down here. It won't work. And the reason it doesn't work is that the Earth itself is moving all over the place all the time. Don't realize it. It seems pretty good to you”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“So we see nothing But if one arm got a little bit longer than the other, then they don't come back at exactly the same time. They don't exactly cancel. That's what we measure. So, to give a number to it, we have to do that to the change of length to be able to do this 10 to the minus 18 meters to one part in 10 to the twelfth. And that was the big experimental challenge that we did. Required a lot of innovation to be able to do.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“About it. Yeah. So in the same idea that I just said, we have two long vacuum pipes, 10 to 4 kilometers long. We start with a laser beam and we divide the beam going down the two arms. And we have a mirror at the other end, reflects it back. It's more subtle, but we bring it back. If there's no distortion in space-time and the links are exactly the same, which we calibrate them to be, then when it comes back, if we just invert one signal compared to the other, they'll just cancel.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Now, to tell you how small that is We're made of that you can't go and grab so easily is 10 to the minus 15 meters. So this is one one thousandth the size of a proton. That's the effect, size of the effect Einstein himself didn't think this could be measured or ever seen. Actually he said that, but that's because he didn't anticipate modern lasers and techniques that we develop”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Four kilometers in each direction. If you take then one part in 10 to the 21, we're talking about measuring something to 10 to the minus 18 meters.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“It's one of them coming back after the other one, but the difference is just one part in 10 to the 21. So, for that reason, we make it big, let the arms be long. Okay, so one part in 10 to the 21. In our case it's kilometers long, so we have an instrument that's a kilometers in one direction, kilometers in the other. How many kilometers we'll talk about?”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“Okay, so the measurement that we have to do is a distortion in time. How big is it? One, it's a distortion that's one part in 10 to the 21. That's 21 zeros and a one.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source
“And what it does is it just basically takes usually light and the two directions that we're talking about, you send light down one direction and the perpendicular direction. And if nothing changes, it takes the same and the arms are the same length. It just goes down, bounces back. And if you invert one compared to the other, they cancel. So there's nothing happens. But if it's like the amusement park and one of the arms got shorter and fatter, so it took longer to go horizontally than it did to go vertically. Then when they come back, when the light comes back, it comes back somewhat out of time. And that basically is the scheme. The only problem is that that's not done very accurately in general, and we had to do it extremely accurately.”
2021-08-23 · Lex Fridman Podcast · #213 – Barry Barish: Gravitational Waves and the Most Precise Device Ever Built · IDENTIFIED FROM THE TRANSCRIPT · source