1 00:00:04,360 --> 00:00:12,560 Speaker 1: Welcome to Tech Stuff, a production from iHeartRadio. Hey there, 2 00:00:12,680 --> 00:00:16,760 Speaker 1: and welcome to tech Stuff. I'm your host Jonathan Strickland. 3 00:00:16,880 --> 00:00:21,160 Speaker 1: I'm an executive producer with iHeartRadio and how the tech 4 00:00:21,320 --> 00:00:25,599 Speaker 1: are here. It is time for a classic episode. This 5 00:00:25,680 --> 00:00:29,680 Speaker 1: one is called How Lego Works. Originally published on February 6 00:00:29,760 --> 00:00:33,440 Speaker 1: twenty fourth, twenty sixteen. This was really cool because this 7 00:00:33,520 --> 00:00:38,479 Speaker 1: came out shortly after we were learning about how Lego 8 00:00:38,920 --> 00:00:42,639 Speaker 1: had detected gravitational waves, which up to that point had 9 00:00:42,720 --> 00:00:47,239 Speaker 1: largely been a hypothetical concept. So this was one of 10 00:00:47,240 --> 00:00:50,279 Speaker 1: those things where we finally figured out a way to 11 00:00:50,560 --> 00:00:55,760 Speaker 1: detect something that had been hypothesized about but previously undetected, 12 00:00:56,080 --> 00:01:02,600 Speaker 1: So really cool use of technology. Then the Ligo Observatory 13 00:01:02,800 --> 00:01:06,720 Speaker 1: had picked up a gravitational wave, and this was huge 14 00:01:06,880 --> 00:01:10,880 Speaker 1: news around the world. And in case you were wondering, 15 00:01:10,959 --> 00:01:13,600 Speaker 1: what the heck is this news all about? How did 16 00:01:13,600 --> 00:01:17,080 Speaker 1: they pick up that gravitational wave? What exactly is the 17 00:01:17,120 --> 00:01:22,320 Speaker 1: technology powering our sensors to detect this stuff? How does 18 00:01:22,319 --> 00:01:25,160 Speaker 1: it all work? That's what this episode's all about. So 19 00:01:25,480 --> 00:01:27,800 Speaker 1: this was the very first time anyone had been able 20 00:01:27,840 --> 00:01:32,039 Speaker 1: to measure a gravitational wave directly So today we're going 21 00:01:32,120 --> 00:01:36,080 Speaker 1: to talk all about what that means and how it happened. Now, 22 00:01:36,120 --> 00:01:39,800 Speaker 1: to begin with, we need to lay some groundwork and 23 00:01:40,000 --> 00:01:43,360 Speaker 1: to really get an understanding of what gravitational waves are. 24 00:01:44,000 --> 00:01:48,639 Speaker 1: So gravitational waves ultimately were one of the predictions made 25 00:01:48,760 --> 00:01:54,040 Speaker 1: by a certain Albert Einstein with this theory of general relativity. 26 00:01:54,160 --> 00:01:58,160 Speaker 1: So in that theory, Einstein presented this idea that our 27 00:01:58,240 --> 00:02:02,720 Speaker 1: universe is filled with spacetime. If you're a fan of 28 00:02:02,720 --> 00:02:07,240 Speaker 1: science fiction, you have undoubtedly come across that term star 29 00:02:07,320 --> 00:02:10,079 Speaker 1: trek is all about the spacetime continuum, and that you've 30 00:02:10,080 --> 00:02:12,000 Speaker 1: got to be careful. You could rip a hole in 31 00:02:12,040 --> 00:02:15,399 Speaker 1: the fabric of spacetime. As far as we know, that's 32 00:02:15,440 --> 00:02:19,480 Speaker 1: not really that possible. I mean, black holes could sort 33 00:02:19,520 --> 00:02:22,640 Speaker 1: of be that maybe, But at any rate, spacetime itself 34 00:02:22,720 --> 00:02:27,520 Speaker 1: is this calling it stuff is probably the wrong way 35 00:02:27,520 --> 00:02:29,920 Speaker 1: of putting it, but it is like a fabric and 36 00:02:30,240 --> 00:02:34,480 Speaker 1: mass hangs inside this fabric, And by mass, i'm talking 37 00:02:34,480 --> 00:02:38,320 Speaker 1: about stuff like stars or even an entire solar systems 38 00:02:38,440 --> 00:02:43,760 Speaker 1: or galaxies that hang in this fabric, and just like 39 00:02:44,040 --> 00:02:48,440 Speaker 1: you would see in a two dimensional display, it ends 40 00:02:48,520 --> 00:02:53,320 Speaker 1: up curving the fabric around the mass. We often talk 41 00:02:53,480 --> 00:02:58,000 Speaker 1: about this in terms of a very simple example that's 42 00:02:58,000 --> 00:03:01,760 Speaker 1: easy to imagine. You get some sort of stretching material. 43 00:03:01,840 --> 00:03:04,559 Speaker 1: Often you'll just hear someone say, okay, get a trampoline. 44 00:03:04,639 --> 00:03:08,079 Speaker 1: You've got a trampoline, and you put a big, heavy 45 00:03:08,160 --> 00:03:11,639 Speaker 1: bowling ball on the trampoline. So that bowling ball is 46 00:03:11,680 --> 00:03:15,320 Speaker 1: going to deform the trampoline surface. It's no longer going 47 00:03:15,360 --> 00:03:18,560 Speaker 1: to be straight. It's going to end up curving around 48 00:03:18,600 --> 00:03:20,840 Speaker 1: the bowling ball to some extent, creating kind of a 49 00:03:21,000 --> 00:03:25,560 Speaker 1: dmple where the bowling ball has has created this impression 50 00:03:25,600 --> 00:03:27,760 Speaker 1: inside the trampoline, and as long as the bowling ball 51 00:03:27,840 --> 00:03:31,280 Speaker 1: is there, that impression is going to stay. This is 52 00:03:31,320 --> 00:03:34,880 Speaker 1: sort of the like the way spacetime curves around giant 53 00:03:34,920 --> 00:03:40,400 Speaker 1: masses like stars and black holes things like that. Of course, 54 00:03:40,800 --> 00:03:43,880 Speaker 1: we have to remember that spacetime is actually four dimensional, 55 00:03:44,000 --> 00:03:46,640 Speaker 1: not a two dimensional thing like a trampoline. I mean, 56 00:03:46,680 --> 00:03:49,800 Speaker 1: I know that trampolines technically have three dimensions, but we're 57 00:03:49,840 --> 00:03:51,840 Speaker 1: really looking at a surface, so it's more like a 58 00:03:51,920 --> 00:03:56,320 Speaker 1: two dimensional plane. In reality. In spacetime it's four dimensional 59 00:03:56,320 --> 00:04:00,400 Speaker 1: because you've got the three spatial dimensions plus time, and 60 00:04:00,480 --> 00:04:02,600 Speaker 1: that is a little difficult to get your head around. 61 00:04:03,400 --> 00:04:05,680 Speaker 1: But that's why we tend to look at this two 62 00:04:05,680 --> 00:04:08,360 Speaker 1: dimensional example. It's a lot easier for us to imagine. 63 00:04:08,880 --> 00:04:12,240 Speaker 1: So let's go a little further with that analogy to 64 00:04:12,320 --> 00:04:15,320 Speaker 1: kind of talk about gravity. See Einstein proposed that gravity 65 00:04:15,440 --> 00:04:19,120 Speaker 1: was a manifestation of this curved space time. And if 66 00:04:19,120 --> 00:04:21,599 Speaker 1: we take that trampoline example, Let's say that you have 67 00:04:21,680 --> 00:04:23,800 Speaker 1: a regular trampoline. You haven't put the bowling ball on 68 00:04:23,839 --> 00:04:26,359 Speaker 1: there yet, so it's a nice flat surface, and you 69 00:04:26,400 --> 00:04:28,839 Speaker 1: have a marble, and you roll the marble across the 70 00:04:28,839 --> 00:04:31,279 Speaker 1: surface of the trampoline. So if there's nothing else there, 71 00:04:31,279 --> 00:04:33,880 Speaker 1: and if the trampoline is level, if the surface is level, 72 00:04:34,800 --> 00:04:37,280 Speaker 1: the marble should just roll in the straight line from 73 00:04:37,320 --> 00:04:40,359 Speaker 1: one side of the trampoline to the other, no problem. 74 00:04:40,560 --> 00:04:42,599 Speaker 1: Now let's say you put that big, heavy bowling ball 75 00:04:42,600 --> 00:04:45,200 Speaker 1: on the trampoline. It creates that dimple, and then you 76 00:04:45,240 --> 00:04:48,680 Speaker 1: try and roll the marble across the trampoline surface. Well, 77 00:04:48,720 --> 00:04:51,800 Speaker 1: now that dimple is going to end up affecting the 78 00:04:51,800 --> 00:04:54,400 Speaker 1: pathway of the marble. It's going to start to spiral 79 00:04:54,520 --> 00:04:58,920 Speaker 1: inward toward the bowling ball. Ultimately it'll end up making 80 00:04:58,960 --> 00:05:02,680 Speaker 1: contact with the bowling ball, and Einstein said, that's essentially 81 00:05:02,680 --> 00:05:07,120 Speaker 1: what gravity is. It's that you've got these large masses 82 00:05:07,640 --> 00:05:12,000 Speaker 1: that curves spacetime to the extent that smaller masses are 83 00:05:12,120 --> 00:05:15,520 Speaker 1: spiraling inward toward the large mass. It's just happening on 84 00:05:15,560 --> 00:05:18,960 Speaker 1: a scale that's much much, much larger than any bowling ball, 85 00:05:19,040 --> 00:05:23,919 Speaker 1: marble example. But that this isn't essentially what we see 86 00:05:23,960 --> 00:05:28,400 Speaker 1: when we see planets orbiting a sun, or we see 87 00:05:28,560 --> 00:05:31,719 Speaker 1: a moon orbiting a planet, or we see star systems 88 00:05:31,800 --> 00:05:34,720 Speaker 1: orbiting a galaxy, you know, the center of a galaxy, 89 00:05:35,480 --> 00:05:40,159 Speaker 1: and it's all because of this curve spacetime. Now, all 90 00:05:40,160 --> 00:05:42,880 Speaker 1: of that already is pretty heavy stuff. And keep in mind, 91 00:05:42,920 --> 00:05:47,120 Speaker 1: there was not really any way to directly observe this. 92 00:05:47,320 --> 00:05:53,000 Speaker 1: It was mostly the the just Einstein using logic to 93 00:05:53,760 --> 00:05:57,239 Speaker 1: work all this out and math, logic and math, and 94 00:05:58,480 --> 00:06:02,200 Speaker 1: ultimately it fit with what we saw of the universe. 95 00:06:02,240 --> 00:06:04,520 Speaker 1: But we weren't able to test a lot of this. 96 00:06:05,080 --> 00:06:08,800 Speaker 1: But then it gets even more mind blowing because now 97 00:06:08,800 --> 00:06:12,400 Speaker 1: we have to get to gravitational waves. So Einstein said 98 00:06:12,400 --> 00:06:15,400 Speaker 1: that if a mass were large enough and either changed 99 00:06:15,680 --> 00:06:19,760 Speaker 1: shape rapidly enough or it changed its movement in some way, 100 00:06:21,120 --> 00:06:24,320 Speaker 1: really really quickly. It would cause ripples of space time 101 00:06:24,360 --> 00:06:28,920 Speaker 1: to move outward from that event at the speed of light. 102 00:06:29,440 --> 00:06:32,479 Speaker 1: And those ripples are what we call gravitational waves, which 103 00:06:32,480 --> 00:06:35,479 Speaker 1: are different from gravity waves. By the way, I have 104 00:06:35,520 --> 00:06:38,920 Speaker 1: been known to accidentally say gravity waves instead of gravitational waves, 105 00:06:38,920 --> 00:06:41,719 Speaker 1: but the two are different things. A gravity wave is 106 00:06:41,720 --> 00:06:45,840 Speaker 1: a wave that exists because of gravity. In other words, 107 00:06:45,880 --> 00:06:48,360 Speaker 1: it's a physical wave of some sort of fluid system, 108 00:06:48,400 --> 00:06:53,200 Speaker 1: whether it's atmosphere or water or some other liquid. That's 109 00:06:53,240 --> 00:06:55,960 Speaker 1: a gravity wave on a planet's surface. It's not the 110 00:06:56,000 --> 00:06:58,159 Speaker 1: same thing as a gravitational wave, which is really a 111 00:06:58,240 --> 00:07:01,400 Speaker 1: ripple of space time, and like I said, it moves 112 00:07:01,440 --> 00:07:04,280 Speaker 1: outward from that event at the speed of light. And 113 00:07:04,360 --> 00:07:08,160 Speaker 1: stuff that could cause significant gravitational waves, things that would 114 00:07:08,160 --> 00:07:10,800 Speaker 1: be big enough for us to potentially pick up here 115 00:07:10,880 --> 00:07:13,520 Speaker 1: on Earth if we had the right equipment, would include 116 00:07:13,520 --> 00:07:16,680 Speaker 1: things like two black holes orbiting or colliding with one another, 117 00:07:16,840 --> 00:07:20,160 Speaker 1: which in fact, that was the event that we were 118 00:07:20,200 --> 00:07:24,280 Speaker 1: able to pick up with the Ligo facilities. And I'll 119 00:07:24,320 --> 00:07:27,600 Speaker 1: talk about those in just a bit. But there could 120 00:07:27,640 --> 00:07:30,320 Speaker 1: be other stuff too, like neutron stars orbiting one another 121 00:07:30,440 --> 00:07:35,960 Speaker 1: fast enough would generate gravitational waves, or a supernova explosion 122 00:07:36,240 --> 00:07:38,840 Speaker 1: would create one as well. And each of these events 123 00:07:38,880 --> 00:07:41,760 Speaker 1: give off a huge amount of energy, and some of 124 00:07:41,800 --> 00:07:44,760 Speaker 1: that energy gets converted into making these gravitational waves. So 125 00:07:44,840 --> 00:07:48,239 Speaker 1: one takeaway from this prediction something that Einstein said would happen, 126 00:07:49,240 --> 00:07:53,720 Speaker 1: is that any event that produces gravitational waves is an 127 00:07:53,720 --> 00:07:57,040 Speaker 1: event in which energy is being lost, So you would 128 00:07:57,040 --> 00:08:02,160 Speaker 1: expect to see less energy within that system afterward than before. 129 00:08:03,160 --> 00:08:06,400 Speaker 1: And it would be a hundred years from the time 130 00:08:06,440 --> 00:08:10,560 Speaker 1: of publication of the theory of general relativity to the 131 00:08:10,600 --> 00:08:13,760 Speaker 1: time when scientists announced that they had detected a gravitational 132 00:08:13,840 --> 00:08:19,520 Speaker 1: wave directly. And that's because gravitational waves are devilishly difficult 133 00:08:19,560 --> 00:08:22,760 Speaker 1: to detect. And that's some alliteration for you right there. 134 00:08:23,520 --> 00:08:27,080 Speaker 1: So gravitational waves are invisible. They don't emit any sort 135 00:08:27,120 --> 00:08:31,160 Speaker 1: of electromagnetic radiation, so we can't see them. We can't 136 00:08:31,200 --> 00:08:36,480 Speaker 1: detect them with radio detectors, nothing like that, and that 137 00:08:36,520 --> 00:08:39,000 Speaker 1: makes it pretty tricky to figure out where they are. 138 00:08:39,559 --> 00:08:41,760 Speaker 1: But they do just pass through the universe. They don't 139 00:08:41,920 --> 00:08:46,520 Speaker 1: get absorbed or scattered the way electromagnetic radiation does. If 140 00:08:46,520 --> 00:08:48,920 Speaker 1: you hold up a mirror and light hits the mirror, 141 00:08:49,040 --> 00:08:51,600 Speaker 1: light will bounce off the mirror. That's not the case 142 00:08:51,679 --> 00:08:56,079 Speaker 1: with gravitational waves. They pass right through, so it's a 143 00:08:56,160 --> 00:09:02,720 Speaker 1: very different thing than electromagnetic radiation. And while they're generated 144 00:09:02,800 --> 00:09:06,160 Speaker 1: from enormous events, the gravitational waves aren't very strong. By 145 00:09:06,160 --> 00:09:09,760 Speaker 1: the time they get to Earth. They are pretty weak, 146 00:09:10,160 --> 00:09:13,000 Speaker 1: so weak that you would need an incredibly sensitive tool 147 00:09:13,080 --> 00:09:15,240 Speaker 1: in order to pick them up. And also you have 148 00:09:15,280 --> 00:09:17,880 Speaker 1: to be searching at the right time, because if the 149 00:09:17,960 --> 00:09:22,200 Speaker 1: event that generated the gravitational waves happened a billion years ago, 150 00:09:22,920 --> 00:09:25,920 Speaker 1: but the location is four billion light years from Earth, 151 00:09:26,880 --> 00:09:29,520 Speaker 1: then we would have to wait another three billion years 152 00:09:29,960 --> 00:09:33,000 Speaker 1: for those gravitational waves to get to us, because again, 153 00:09:33,040 --> 00:09:35,160 Speaker 1: they travel at the speed of light. That's their limit. 154 00:09:36,000 --> 00:09:37,680 Speaker 1: So you have to be at the right place at 155 00:09:37,720 --> 00:09:41,280 Speaker 1: the right time to pick these things up, and in 156 00:09:41,320 --> 00:09:45,959 Speaker 1: some cases you might argue that that's incredibly fortuitous. Although 157 00:09:46,679 --> 00:09:50,760 Speaker 1: to be fair, it looks like the events that could 158 00:09:50,840 --> 00:09:54,679 Speaker 1: generate gravitational waves happen pretty frequently throughout the universe. But 159 00:09:54,760 --> 00:09:58,240 Speaker 1: the universe is huge, so if they're happening far away, 160 00:09:58,679 --> 00:10:01,200 Speaker 1: far enough away, will take a very long time for 161 00:10:01,240 --> 00:10:04,920 Speaker 1: that information to get to us. So before the announcement 162 00:10:04,960 --> 00:10:08,600 Speaker 1: on February eleventh, twenty sixteen, scientists had observed phenomena that 163 00:10:08,800 --> 00:10:13,080 Speaker 1: supported the existence of gravitational waves, but were not direct 164 00:10:13,280 --> 00:10:17,199 Speaker 1: observations of a gravitational wave. Here's an example. A pair 165 00:10:17,240 --> 00:10:20,880 Speaker 1: of astronomers in Puerto Rico in the nineteen seventies noticed 166 00:10:20,920 --> 00:10:25,360 Speaker 1: that there was a binary pulsar system and they went 167 00:10:25,400 --> 00:10:28,439 Speaker 1: back to the theory of general relativity because this was 168 00:10:28,480 --> 00:10:31,200 Speaker 1: a sort of system that would be exactly the type 169 00:10:31,240 --> 00:10:35,360 Speaker 1: to generate gravitational waves according to the predictions from general relativity, 170 00:10:36,080 --> 00:10:39,800 Speaker 1: and because general relativity predicted, hey, if it can create 171 00:10:39,840 --> 00:10:44,160 Speaker 1: gravitational waves, it's going to lose energy over time, they 172 00:10:44,640 --> 00:10:47,559 Speaker 1: ended up coming up with the hypothesis that, well, over time, 173 00:10:47,640 --> 00:10:51,360 Speaker 1: this binary pulsar system should start to slow down because 174 00:10:51,360 --> 00:10:54,600 Speaker 1: it's losing energy. It can't keep up at the speed 175 00:10:54,640 --> 00:10:59,120 Speaker 1: it's going. So they decided to keep an eye on it. 176 00:10:59,400 --> 00:11:01,760 Speaker 1: And by keeping an eye on it, I mean they 177 00:11:01,840 --> 00:11:06,360 Speaker 1: continue to observe this pulsar system over the course of 178 00:11:06,400 --> 00:11:09,760 Speaker 1: eight years, and by the end of the eight year period, 179 00:11:09,760 --> 00:11:13,280 Speaker 1: they were comparing the findings they were observing to the 180 00:11:13,320 --> 00:11:16,319 Speaker 1: predictions made by general relativity, and they were matching up. 181 00:11:17,040 --> 00:11:20,960 Speaker 1: It was unfolding exactly the way Einstein predicted it should 182 00:11:21,040 --> 00:11:25,160 Speaker 1: unfold based upon his theory of general relativity, which is 183 00:11:25,200 --> 00:11:28,080 Speaker 1: incredible when you think about it, that the observations are 184 00:11:28,120 --> 00:11:32,160 Speaker 1: matching up so neatly against the predictions. You know, it 185 00:11:32,200 --> 00:11:37,360 Speaker 1: just shows how how keenly aware Einstein was of how 186 00:11:37,400 --> 00:11:40,720 Speaker 1: our universe appears to work. Keeping in mind that general relativity, 187 00:11:41,160 --> 00:11:47,520 Speaker 1: while an amazing idea collection of ideas, really it doesn't 188 00:11:47,960 --> 00:11:52,160 Speaker 1: encompass everything that we know, right. It doesn't really address 189 00:11:52,240 --> 00:11:55,600 Speaker 1: quantum mechanics, for example, at least not in a way 190 00:11:55,600 --> 00:12:01,200 Speaker 1: that incorporates it with classical physics. But based upon what 191 00:12:01,280 --> 00:12:04,160 Speaker 1: it did cover, it seems like it was an incredibly 192 00:12:04,280 --> 00:12:10,520 Speaker 1: accurate theory, all right. So this was really considered strong 193 00:12:10,640 --> 00:12:15,199 Speaker 1: but indirect support of gravitational waves, because again the astronomers 194 00:12:15,200 --> 00:12:18,680 Speaker 1: didn't observe gravitational waves directly. They couldn't see them or 195 00:12:18,720 --> 00:12:23,240 Speaker 1: detect them, but they could see the effects, and again 196 00:12:23,280 --> 00:12:26,320 Speaker 1: it was matching up with the predictions made from general relativity. 197 00:12:26,400 --> 00:12:30,160 Speaker 1: So it was good indirect evidence that gravitational waves existed. 198 00:12:31,160 --> 00:12:32,880 Speaker 1: Then there was an event a couple of years ago 199 00:12:33,600 --> 00:12:37,520 Speaker 1: that you might have heard about when a team of 200 00:12:38,000 --> 00:12:42,600 Speaker 1: researchers working on the BICEP two telescope, which is an 201 00:12:43,080 --> 00:12:47,920 Speaker 1: Antarctica had announced that they thought they might have discovered 202 00:12:48,000 --> 00:12:54,120 Speaker 1: evidence of gravitational waves that supported a hypothesis called cosmic inflation. 203 00:12:55,400 --> 00:12:57,360 Speaker 1: That's a lot of information right there, So let me 204 00:12:57,400 --> 00:13:02,439 Speaker 1: explain what all that means. Cosmic inflation is a hypothesis 205 00:13:02,480 --> 00:13:05,840 Speaker 1: that relates to the Big Bang theory. So, with the 206 00:13:05,840 --> 00:13:08,880 Speaker 1: Big Bang theory, you've got this event in which the 207 00:13:09,000 --> 00:13:13,920 Speaker 1: universe undergoes a period of rapid expansion. Cosmic inflation is 208 00:13:14,440 --> 00:13:19,720 Speaker 1: kind of that rapid expansion on steroids. The idea being that, well, 209 00:13:19,880 --> 00:13:22,400 Speaker 1: when we look at our universe and we look at 210 00:13:23,920 --> 00:13:27,880 Speaker 1: what we can observe, it appears that our observations don't 211 00:13:27,920 --> 00:13:31,560 Speaker 1: quite match up with what we would expect if we 212 00:13:31,920 --> 00:13:38,440 Speaker 1: had just steady expansion since the Big Bang. In other words, 213 00:13:38,800 --> 00:13:41,079 Speaker 1: we look at all the information we have available to us, 214 00:13:41,160 --> 00:13:44,440 Speaker 1: and it looks to us that it doesn't quite match up. 215 00:13:44,480 --> 00:13:49,000 Speaker 1: Something's got to be wrong. Well, one possible explanation is 216 00:13:49,040 --> 00:13:52,360 Speaker 1: that shortly after the Big Bang, and by shortly, I 217 00:13:52,400 --> 00:13:56,280 Speaker 1: mean tend to the negative thirty sixth power seconds after 218 00:13:56,360 --> 00:13:59,320 Speaker 1: the Big Bang, So you take a ten, you put 219 00:13:59,320 --> 00:14:01,640 Speaker 1: a decimal point behind the ten, then you move the 220 00:14:01,640 --> 00:14:05,360 Speaker 1: decimal point to the left thirty six times that you 221 00:14:05,440 --> 00:14:08,040 Speaker 1: put seconds behind that. We're talking a fraction of a 222 00:14:08,080 --> 00:14:12,040 Speaker 1: fraction of a fraction of a second. The universe underwent 223 00:14:12,640 --> 00:14:17,559 Speaker 1: massive expansion, and it only lasted from that point to 224 00:14:17,679 --> 00:14:20,640 Speaker 1: about ten to the negative thirty third power or thirty 225 00:14:20,680 --> 00:14:28,280 Speaker 1: second power seconds. So again an instant. It's completely unimaginable, 226 00:14:28,520 --> 00:14:31,960 Speaker 1: at least for myself, how short an amount of time 227 00:14:32,000 --> 00:14:37,280 Speaker 1: this was. But that's how quickly the universe expanded significantly, 228 00:14:37,880 --> 00:14:42,200 Speaker 1: and then it slowed, but it continued to expand. Now, 229 00:14:42,360 --> 00:14:46,560 Speaker 1: if in fact, cosmic inflation is correct, it solves a 230 00:14:46,560 --> 00:14:49,360 Speaker 1: lot of the problems we have between the what we 231 00:14:49,440 --> 00:14:52,880 Speaker 1: observe today and what we believe happened with the Big Bang, 232 00:14:53,880 --> 00:14:58,720 Speaker 1: and reconciles those differences. If cosmic inflation is wrong, then 233 00:14:58,800 --> 00:15:02,280 Speaker 1: something else that we believe is wrong. Right. It means 234 00:15:02,320 --> 00:15:06,600 Speaker 1: that what we observe either isn't representative of reality somehow 235 00:15:06,640 --> 00:15:08,920 Speaker 1: we're not getting a big enough picture to understand it, 236 00:15:09,680 --> 00:15:12,400 Speaker 1: or that the Big Bang theory itself is flawed in 237 00:15:12,440 --> 00:15:16,920 Speaker 1: some fundamental way. Hey, we'll be back with this heavy 238 00:15:16,960 --> 00:15:21,120 Speaker 1: subject of detecting gravitational waves with LEGO after this short break, 239 00:15:30,960 --> 00:15:33,800 Speaker 1: so the BIS of two team what they were looking 240 00:15:33,800 --> 00:15:37,360 Speaker 1: for was some evidence of gravitational waves that would have 241 00:15:37,400 --> 00:15:41,200 Speaker 1: been generated during the Big Bang. This would end up 242 00:15:41,240 --> 00:15:44,520 Speaker 1: supporting the cosmic inflation hypothesis. And the way they did 243 00:15:44,600 --> 00:15:47,480 Speaker 1: this was they were looking at the cosmic microwave background 244 00:15:47,640 --> 00:15:52,320 Speaker 1: or CMBAM. Now, the cosmic microwave background emerged about three 245 00:15:52,400 --> 00:15:57,040 Speaker 1: hundred eighty thousand years after the Big Bang. This was 246 00:15:57,080 --> 00:15:59,720 Speaker 1: still a period where the universe was so dense that 247 00:16:00,000 --> 00:16:02,800 Speaker 1: I could not pass through it. It was dark and dense, 248 00:16:03,440 --> 00:16:07,800 Speaker 1: but the cosmic microwave background formed around that time, and 249 00:16:07,880 --> 00:16:14,040 Speaker 1: the hypothesis stated, well, gravitational waves would have affected the 250 00:16:14,160 --> 00:16:19,160 Speaker 1: cosmic microwave background, polarizing some of those some of those 251 00:16:20,000 --> 00:16:24,080 Speaker 1: particles really not particles, but some of that energy polarizing 252 00:16:24,120 --> 00:16:26,760 Speaker 1: some of the cosmic microwave background in such a way 253 00:16:26,800 --> 00:16:30,240 Speaker 1: that if you were to observe it, you could see 254 00:16:30,280 --> 00:16:34,960 Speaker 1: the effect of a gravitational wave passing through the cmb 255 00:16:36,800 --> 00:16:42,400 Speaker 1: And then as the universe expand expanded, rather that mark 256 00:16:42,600 --> 00:16:45,760 Speaker 1: would also expand. It's kind of like imagine leaving a 257 00:16:45,800 --> 00:16:50,200 Speaker 1: fingerprint on some sort of stretchy material and then stretching 258 00:16:50,240 --> 00:16:53,680 Speaker 1: that material out, the fingerprint is still there. It's deformed, 259 00:16:53,720 --> 00:16:56,200 Speaker 1: but still there. That's what the BICEP two team was 260 00:16:56,240 --> 00:16:59,880 Speaker 1: looking for, was this pattern in the CMB that would 261 00:17:00,040 --> 00:17:03,680 Speaker 1: indicate that gravitational waves from the Big Bang had passed through, 262 00:17:04,320 --> 00:17:06,400 Speaker 1: and if they found that, that would be a huge 263 00:17:06,400 --> 00:17:10,359 Speaker 1: support for cosmic inflation. And in the spring of twenty fourteen, 264 00:17:10,359 --> 00:17:13,800 Speaker 1: they announced that they believed they had found such evidence, 265 00:17:14,800 --> 00:17:18,040 Speaker 1: and they also invited other researchers to take a look 266 00:17:18,040 --> 00:17:21,320 Speaker 1: at their data and see if it was verifiable or 267 00:17:21,480 --> 00:17:25,680 Speaker 1: maybe they overlooked something. And in the fall of twenty fourteen, 268 00:17:25,840 --> 00:17:29,040 Speaker 1: another team said, we're sorry, but it looks to us 269 00:17:29,960 --> 00:17:34,159 Speaker 1: like space dust might have created a false positive that 270 00:17:35,080 --> 00:17:38,479 Speaker 1: what you thought it was the polarized CMB that you 271 00:17:38,520 --> 00:17:41,920 Speaker 1: had been looking for was actually just space dust that's 272 00:17:41,960 --> 00:17:47,160 Speaker 1: not actually part of the CMB. And so that ended 273 00:17:47,200 --> 00:17:50,840 Speaker 1: up kind of putting a dampener on the whole celebration 274 00:17:50,920 --> 00:17:54,480 Speaker 1: of finding gravitational waves to support cosmic inflation. But even 275 00:17:54,480 --> 00:17:57,840 Speaker 1: if it was completely verified, even if BICEP two had 276 00:17:58,200 --> 00:18:01,399 Speaker 1: irrefutable evidence that they had found the presence of gravitational 277 00:18:01,400 --> 00:18:07,040 Speaker 1: waves through a you know, the way it affected the CMB. 278 00:18:07,800 --> 00:18:11,560 Speaker 1: Even then that's not direct detection. It's still indirect. You're 279 00:18:11,560 --> 00:18:17,520 Speaker 1: looking at the way it's affected something else. So you know, 280 00:18:17,760 --> 00:18:20,720 Speaker 1: again we're still not discovering one. And part of that 281 00:18:20,800 --> 00:18:23,520 Speaker 1: is that BICEP two is a telescope. It's looking at 282 00:18:23,520 --> 00:18:27,920 Speaker 1: through the electromagnetic spectrum, and again, gravitational waves don't show 283 00:18:28,000 --> 00:18:30,840 Speaker 1: up that way. So no telescope would help you find 284 00:18:30,920 --> 00:18:33,879 Speaker 1: a gravitational wave directly. You might be able to find 285 00:18:34,320 --> 00:18:37,720 Speaker 1: how it affected something else, but not the wave itself. 286 00:18:38,840 --> 00:18:42,040 Speaker 1: Now that's not the case with the LIGO observatories. Actually 287 00:18:42,080 --> 00:18:46,640 Speaker 1: it's technically one observatory, but it has four different facilities, 288 00:18:47,000 --> 00:18:51,800 Speaker 1: two detectors and two research facilities that are all part 289 00:18:51,840 --> 00:18:56,439 Speaker 1: of the LIGO observatory. LIGO itself is an acronym and 290 00:18:56,560 --> 00:19:02,760 Speaker 1: it stands for Laser Interferometer Gravitational Wave Observatory. So it's 291 00:19:02,840 --> 00:19:05,560 Speaker 1: a pair of giant detectors built on the surface of 292 00:19:05,560 --> 00:19:09,320 Speaker 1: the Earth. One is located in Hanford, Washington, the other 293 00:19:09,400 --> 00:19:14,000 Speaker 1: is in Livingstone, Louisiana. Now they're about just a little 294 00:19:14,080 --> 00:19:17,159 Speaker 1: under two thousand miles apart, or just over three thousand 295 00:19:17,240 --> 00:19:20,600 Speaker 1: kilometers apart from each other, and that's really important. I'll 296 00:19:20,600 --> 00:19:23,919 Speaker 1: explain why in a little bit. So to understand how 297 00:19:23,960 --> 00:19:25,680 Speaker 1: they work, we also have to talk about something else 298 00:19:25,720 --> 00:19:30,280 Speaker 1: that gravitational waves do as they pass through space. They 299 00:19:30,359 --> 00:19:35,719 Speaker 1: stretch and compress space itself. So again, if you were 300 00:19:35,920 --> 00:19:38,960 Speaker 1: if you were to take a piece of elastic, I'd say, 301 00:19:38,960 --> 00:19:42,240 Speaker 1: you've got a rubber band, a nice thick rubber band, 302 00:19:43,200 --> 00:19:45,959 Speaker 1: and you cut it so that it's just one strip. 303 00:19:46,800 --> 00:19:49,720 Speaker 1: When you pull on that rubber band, it stretches along 304 00:19:49,960 --> 00:19:53,720 Speaker 1: the line where you're applying force, So it stretches in 305 00:19:53,800 --> 00:19:58,920 Speaker 1: that direction, in the perpendicular direction ninety degrees from where 306 00:19:58,920 --> 00:20:04,040 Speaker 1: you're pulling. It compresses, it gets more narrow, and then 307 00:20:04,080 --> 00:20:07,200 Speaker 1: when you let it return to its normal shape, it 308 00:20:07,320 --> 00:20:10,560 Speaker 1: gets you know, the long part ends up getting shorter 309 00:20:10,720 --> 00:20:13,920 Speaker 1: and the narrow part ends up getting wider as a result, 310 00:20:15,200 --> 00:20:18,560 Speaker 1: gravitational waves do this to reality. They do this to 311 00:20:18,640 --> 00:20:22,760 Speaker 1: actual space. They stretch and compress, and it happens several 312 00:20:22,800 --> 00:20:26,639 Speaker 1: times as the wave oscillates through. Really I should just 313 00:20:26,680 --> 00:20:30,680 Speaker 1: say as the wave passes through, rather than oscillates. The 314 00:20:30,760 --> 00:20:35,200 Speaker 1: distortion oscillates, but the wave passes through, so That means 315 00:20:35,200 --> 00:20:40,359 Speaker 1: the actual distance changes between two points as that gravitational 316 00:20:40,359 --> 00:20:42,679 Speaker 1: wave passes through that area. So if we were to 317 00:20:42,720 --> 00:20:47,520 Speaker 1: magnify this effect, and I mean magnify it to a 318 00:20:47,680 --> 00:20:50,760 Speaker 1: ludicrous degree, you would be able to see it. You 319 00:20:50,760 --> 00:20:53,719 Speaker 1: would actually be able to witness this. You could stand 320 00:20:53,800 --> 00:20:57,040 Speaker 1: ten feet away from someone else and when the gravitational 321 00:20:57,040 --> 00:21:00,280 Speaker 1: wave passes through, it would make it look like the 322 00:21:00,320 --> 00:21:03,040 Speaker 1: two of you suddenly got further away and then closer 323 00:21:03,040 --> 00:21:04,879 Speaker 1: to each other, and then further away and closer to 324 00:21:04,880 --> 00:21:08,280 Speaker 1: each other, even though you haven't moved anywhere, because the 325 00:21:08,320 --> 00:21:14,840 Speaker 1: distance itself is stretching and compressing. So why don't we 326 00:21:14,960 --> 00:21:17,679 Speaker 1: see that? I mean, if these celestial events that produce 327 00:21:17,720 --> 00:21:20,080 Speaker 1: gravitational waves happen on the order of something like every 328 00:21:20,119 --> 00:21:25,520 Speaker 1: fifteen minutes, why are we all noticing this whibbly wobbly effect. Well, 329 00:21:26,200 --> 00:21:30,160 Speaker 1: it's because the actual distortion that happens here on Earth 330 00:21:31,080 --> 00:21:35,920 Speaker 1: is much much much smaller in magnitude, so much more 331 00:21:36,600 --> 00:21:40,359 Speaker 1: so much smaller that it's difficult to even explain. But 332 00:21:40,760 --> 00:21:43,800 Speaker 1: if you were to have a supernova explode in the 333 00:21:43,840 --> 00:21:48,840 Speaker 1: Milky Way galaxy, in our galaxy, the gravitational waves generated 334 00:21:48,880 --> 00:21:53,200 Speaker 1: by that explosion would maybe be powerful enough to distort 335 00:21:53,240 --> 00:21:56,679 Speaker 1: the distance between the Earth and the Sun by about 336 00:21:56,720 --> 00:22:02,480 Speaker 1: the diameter of a hydrogen atom, so not noticeable to 337 00:22:02,560 --> 00:22:06,600 Speaker 1: any degree, and not at least to human senses. So 338 00:22:06,640 --> 00:22:08,320 Speaker 1: if you were to even go on a smaller scale, 339 00:22:08,359 --> 00:22:11,280 Speaker 1: let's say that you pick two points that are a 340 00:22:11,320 --> 00:22:15,360 Speaker 1: kilometer apart here on the surface of the Earth, the 341 00:22:15,400 --> 00:22:18,680 Speaker 1: amount of distortion would be equivalent to a few thousandth 342 00:22:18,880 --> 00:22:22,600 Speaker 1: of the diameter of a proton, So you're talking about 343 00:22:22,600 --> 00:22:26,680 Speaker 1: a subatomic particle, and just a tiny, tiny, tiny fraction 344 00:22:26,840 --> 00:22:30,159 Speaker 1: of that subatomic particles diameter would be the amount of 345 00:22:30,200 --> 00:22:34,040 Speaker 1: distortion that would happen across a kilometer worth of distance 346 00:22:34,080 --> 00:22:38,520 Speaker 1: here on Earth. Again, that means it's so small that 347 00:22:38,720 --> 00:22:42,760 Speaker 1: it's incredibly difficult to detect, so much so that Einstein 348 00:22:42,880 --> 00:22:46,560 Speaker 1: himself was pretty sure we would never be able to 349 00:22:46,640 --> 00:22:50,159 Speaker 1: directly detect gravitational waves because he could not imagine a 350 00:22:50,200 --> 00:22:53,040 Speaker 1: system that would be sensitive enough to pick up such 351 00:22:53,119 --> 00:22:58,640 Speaker 1: a minute change, a distortion that's happening so quickly because 352 00:22:58,680 --> 00:23:01,920 Speaker 1: it's a fraction of a second, and it's so small 353 00:23:02,119 --> 00:23:07,240 Speaker 1: as to be unnoticeable. So the other problem here is 354 00:23:07,280 --> 00:23:10,280 Speaker 1: not just that it's such a very tiny effect that 355 00:23:10,359 --> 00:23:12,919 Speaker 1: lasts a short amount of time. It's also that a 356 00:23:12,920 --> 00:23:16,359 Speaker 1: lot of other stuff could create false positives. You can 357 00:23:16,440 --> 00:23:22,880 Speaker 1: have incredibly instrumentation, but if that instrument is really really sensitive, 358 00:23:23,400 --> 00:23:26,880 Speaker 1: any sort of interference could set off and you could 359 00:23:26,960 --> 00:23:30,680 Speaker 1: end up getting false readings. So a change in air 360 00:23:30,720 --> 00:23:36,720 Speaker 1: pressure or temperature, or seismic activity, even a heavy truck 361 00:23:36,800 --> 00:23:41,000 Speaker 1: driving nearby could set off false results. So you'd have 362 00:23:41,040 --> 00:23:43,720 Speaker 1: to come up with a really clever way to measure distortion, 363 00:23:43,840 --> 00:23:47,760 Speaker 1: to limit vibration, and to eliminate the chance that it 364 00:23:47,800 --> 00:23:50,679 Speaker 1: was a false positive. And Lego is the answer to 365 00:23:50,760 --> 00:23:54,560 Speaker 1: all of that. So the Lego Observatory is actually the 366 00:23:54,600 --> 00:23:59,120 Speaker 1: result of decades of collaborative work among different scientific research 367 00:23:59,160 --> 00:24:03,240 Speaker 1: centers and internet national bodies and universities, and all started 368 00:24:03,280 --> 00:24:06,639 Speaker 1: back in nineteen seventy nine. That's when the National Science 369 00:24:06,680 --> 00:24:10,560 Speaker 1: Foundation approved funds for Caltech and MIT to develop laser 370 00:24:10,560 --> 00:24:14,399 Speaker 1: interferometer research and development. And a few years later, in 371 00:24:14,480 --> 00:24:17,600 Speaker 1: nineteen eighty three, Caltech and MIT submitted a proposal for 372 00:24:17,680 --> 00:24:22,879 Speaker 1: a kilometer scale detector. But keep in mind, all right, 373 00:24:22,920 --> 00:24:25,159 Speaker 1: so in nineteen seventy nine you get the funding for 374 00:24:25,400 --> 00:24:28,879 Speaker 1: R and d nineteen eighty three, there's the submission of 375 00:24:28,880 --> 00:24:33,840 Speaker 1: a proposal for a kilometer scale detector. There wouldn't be 376 00:24:33,880 --> 00:24:38,520 Speaker 1: approval for a detector until nineteen ninety, so almost a 377 00:24:38,680 --> 00:24:44,720 Speaker 1: decade later, and which turns out was probably okay, because 378 00:24:44,720 --> 00:24:50,240 Speaker 1: we really didn't have the technological ability to detect things 379 00:24:50,280 --> 00:24:53,640 Speaker 1: on a scale small enough to register a gravitational wave 380 00:24:53,640 --> 00:24:57,560 Speaker 1: in the first place. But still, you know, a decade's 381 00:24:57,560 --> 00:24:59,920 Speaker 1: delay before you even get approval is still pretty rough. 382 00:25:00,880 --> 00:25:05,920 Speaker 1: Construction didn't begin until nineteen ninety four. The inauguration of 383 00:25:05,960 --> 00:25:10,119 Speaker 1: the Ligo Observatory took place in nineteen ninety nine, but 384 00:25:10,200 --> 00:25:14,320 Speaker 1: even then that didn't mean that the observatory was online 385 00:25:14,359 --> 00:25:17,640 Speaker 1: collecting data. It didn't do that until two thousand and two. 386 00:25:18,800 --> 00:25:23,320 Speaker 1: And here's the kicker. Eventually scientists came to the conclusion 387 00:25:23,440 --> 00:25:27,719 Speaker 1: that this Ligo observatory was not sensitive enough to detect 388 00:25:27,720 --> 00:25:30,600 Speaker 1: gravitational waves. That despite the fact that it was this 389 00:25:31,440 --> 00:25:36,400 Speaker 1: large detector or pair of large detectors, actually because again 390 00:25:36,440 --> 00:25:40,840 Speaker 1: one in Louisiana one in Washington, it wasn't sensitive enough 391 00:25:41,040 --> 00:25:44,919 Speaker 1: to be effective. So it was not quite back to 392 00:25:44,960 --> 00:25:47,600 Speaker 1: the drawing board, but it did mean that they had 393 00:25:47,640 --> 00:25:52,240 Speaker 1: to think about how they would upgrade these facilities so 394 00:25:52,280 --> 00:25:54,439 Speaker 1: that they could be sensitive enough to pick up a 395 00:25:54,440 --> 00:25:58,320 Speaker 1: gravitational wave. So in twenty ten, Ligo went offline to 396 00:25:58,440 --> 00:26:03,399 Speaker 1: undergo a big overhaul, and it took four years of 397 00:26:03,440 --> 00:26:07,480 Speaker 1: construction and testing to get it into shape and another 398 00:26:07,560 --> 00:26:10,760 Speaker 1: year to set it up for new observations, which means 399 00:26:10,760 --> 00:26:13,080 Speaker 1: that it wasn't until twenty fifteen that it was ready 400 00:26:13,119 --> 00:26:16,399 Speaker 1: to come back online. By now it was called the 401 00:26:16,440 --> 00:26:20,880 Speaker 1: Advanced Ligo Observatory and it began collecting data in September 402 00:26:21,040 --> 00:26:27,600 Speaker 1: twenty fifteen. Literally days after it had come online, it 403 00:26:27,640 --> 00:26:31,600 Speaker 1: picked up a gravitational wave. So that's pretty phenomenal that 404 00:26:31,960 --> 00:26:34,639 Speaker 1: just a couple of days, just a few days really 405 00:26:34,680 --> 00:26:37,919 Speaker 1: after it had been turned on again in twenty fifteen, 406 00:26:38,400 --> 00:26:41,800 Speaker 1: we got a hit. So that was incredibly exciting. So 407 00:26:41,840 --> 00:26:45,520 Speaker 1: how did this happen? How does it actually work? Well, 408 00:26:45,520 --> 00:26:48,080 Speaker 1: we have to take a look at what interferometers are 409 00:26:48,119 --> 00:26:53,399 Speaker 1: all about. An interferometer uses a technique in which electromagnetic 410 00:26:53,440 --> 00:26:58,160 Speaker 1: waves are superimposed on one another in order to get information. Now, 411 00:26:58,240 --> 00:27:00,680 Speaker 1: Ligo does this with a laser beam because it's a 412 00:27:00,760 --> 00:27:05,120 Speaker 1: laser interferometer, and the laser beam gets shot through a 413 00:27:05,160 --> 00:27:09,159 Speaker 1: beam splitter, and the beams, the two beams that result 414 00:27:09,240 --> 00:27:13,600 Speaker 1: go down two long vacuum tubes. So both of the 415 00:27:13,720 --> 00:27:17,520 Speaker 1: Lego detectors are in an L shape. So you've got 416 00:27:17,520 --> 00:27:20,560 Speaker 1: these long, long vacuum tubes that extend two and a 417 00:27:20,600 --> 00:27:24,200 Speaker 1: half miles or about four kilometers out from the crux 418 00:27:24,920 --> 00:27:31,160 Speaker 1: from the angle where they meet up, and each one 419 00:27:31,359 --> 00:27:33,479 Speaker 1: is you know, they're both the same length. They have 420 00:27:33,560 --> 00:27:36,840 Speaker 1: to be exactly the same length. And the way this 421 00:27:36,880 --> 00:27:39,760 Speaker 1: works is that kind of behind the crux, you've got 422 00:27:39,800 --> 00:27:42,199 Speaker 1: a laser that shoots out a beam of light to 423 00:27:42,280 --> 00:27:46,080 Speaker 1: a beam splitter. The splitter does exactly what it sounds like. 424 00:27:46,119 --> 00:27:49,520 Speaker 1: It does. It splits the beam into two separate beams 425 00:27:50,320 --> 00:27:56,880 Speaker 1: with alternating canceling wavelengths. I guess I should say, so 426 00:27:56,920 --> 00:28:01,600 Speaker 1: the troughs and peaks on one match up with the 427 00:28:01,800 --> 00:28:05,080 Speaker 1: peaks and troughs of the other. That's really important when 428 00:28:05,640 --> 00:28:08,400 Speaker 1: we get a little further down the line here. So 429 00:28:10,240 --> 00:28:14,320 Speaker 1: one of those two beams goes down one branch of 430 00:28:14,359 --> 00:28:17,960 Speaker 1: this L shaped detector. The other beam goes down the 431 00:28:18,000 --> 00:28:20,680 Speaker 1: other branch. And keep in mind, like I said, both 432 00:28:20,680 --> 00:28:23,159 Speaker 1: of these branches are exactly the same length. Two and 433 00:28:23,200 --> 00:28:26,600 Speaker 1: a half miles or four kilometers. When the laser gets 434 00:28:26,600 --> 00:28:29,760 Speaker 1: to the end, they hit a mirror. Each beam hits 435 00:28:29,760 --> 00:28:33,560 Speaker 1: a mirror, they come back to the point of origin, 436 00:28:34,160 --> 00:28:41,920 Speaker 1: and because the two laser beams have these counteracting wavelengths, 437 00:28:42,360 --> 00:28:46,320 Speaker 1: they cancel each other out, so the peaks on one 438 00:28:46,400 --> 00:28:49,480 Speaker 1: cancel out the troughs of the other, and vice versa. 439 00:28:49,680 --> 00:28:53,200 Speaker 1: That means that no light gets emitted through this system. 440 00:28:53,440 --> 00:28:56,520 Speaker 1: And that's important because there's actually a light detector that's 441 00:28:56,560 --> 00:28:58,800 Speaker 1: part of this system as well. It's looking for any 442 00:28:58,880 --> 00:29:02,320 Speaker 1: sign of laser light, because a sign of laser light 443 00:29:02,360 --> 00:29:06,840 Speaker 1: would say that something has changed somehow the distances between 444 00:29:06,880 --> 00:29:10,240 Speaker 1: these or the distances represented by these two vacuum tubes 445 00:29:10,280 --> 00:29:13,000 Speaker 1: has changed, and that would be indicative of an event 446 00:29:13,040 --> 00:29:17,800 Speaker 1: like a gravitational wave moving through. So if any light 447 00:29:17,840 --> 00:29:23,200 Speaker 1: shines through, you know something has happened. Essentially, it says 448 00:29:23,240 --> 00:29:25,680 Speaker 1: that there's a mismatch in the lengths of the vacuum 449 00:29:25,680 --> 00:29:30,280 Speaker 1: tubes themselves. So when a gravitational wave passes through, one 450 00:29:30,360 --> 00:29:33,960 Speaker 1: vacuum tube will get shorter while the other gets longer. 451 00:29:34,440 --> 00:29:38,680 Speaker 1: And that's because the two tubes are offset by ninety degrees, 452 00:29:39,720 --> 00:29:42,600 Speaker 1: so one is going to be along one side of 453 00:29:42,600 --> 00:29:45,600 Speaker 1: the wave and that will lengthen the other will be 454 00:29:45,640 --> 00:29:49,600 Speaker 1: along will be perpendicular to that, and will shorten as 455 00:29:49,640 --> 00:29:52,800 Speaker 1: a result. And this means that the lasers will have 456 00:29:52,920 --> 00:29:57,400 Speaker 1: different distances to travel down, So the laser traveling the 457 00:29:57,440 --> 00:30:00,680 Speaker 1: shorter distance takes less time to get back to the crux. 458 00:30:01,240 --> 00:30:03,680 Speaker 1: The laser going down the longer distance takes more time. 459 00:30:04,120 --> 00:30:06,360 Speaker 1: And even though this is only happening within a fraction 460 00:30:06,360 --> 00:30:08,640 Speaker 1: of a second, it's long enough for us to be 461 00:30:08,680 --> 00:30:11,400 Speaker 1: able to detect the difference. And it also means that 462 00:30:11,440 --> 00:30:15,040 Speaker 1: those wavelengths don't match up anymore, they don't cancel each 463 00:30:15,040 --> 00:30:17,880 Speaker 1: other out anymore. So some of that laser light gets 464 00:30:17,880 --> 00:30:22,960 Speaker 1: emitted to the light detector, which then indicates what's going on. 465 00:30:23,880 --> 00:30:28,280 Speaker 1: It knows which one of the branches was short versus long, 466 00:30:28,720 --> 00:30:30,760 Speaker 1: and knows how long it happened. It knows how much 467 00:30:30,760 --> 00:30:34,360 Speaker 1: it oscillated back and forth, because obviously this is continuing 468 00:30:34,560 --> 00:30:38,840 Speaker 1: as these as the gravitational wave moves through, So you 469 00:30:38,880 --> 00:30:41,160 Speaker 1: collect a lot of data in a short amount of time. 470 00:30:41,160 --> 00:30:44,160 Speaker 1: And we're talking like teeny tiny slices of a second. 471 00:30:44,200 --> 00:30:47,040 Speaker 1: As we're getting all this information, which is pretty incredible. 472 00:30:48,240 --> 00:30:51,680 Speaker 1: We're almost done with our discussion about LEGO, but before 473 00:30:51,680 --> 00:30:53,320 Speaker 1: we can do that, we need to take one more 474 00:30:53,400 --> 00:31:06,120 Speaker 1: quick break. So once you get all that data, you 475 00:31:06,160 --> 00:31:09,960 Speaker 1: can then analyze it. Actually, more importantly, before you analyze it, 476 00:31:10,000 --> 00:31:13,200 Speaker 1: you have to verify it. Now. This is why it's 477 00:31:13,240 --> 00:31:16,640 Speaker 1: important that there are two detectors, and it's also important 478 00:31:16,640 --> 00:31:19,280 Speaker 1: that they are so far apart, like three thousand kilometers 479 00:31:19,320 --> 00:31:22,120 Speaker 1: apart from each other. That's because if you get a 480 00:31:22,120 --> 00:31:26,160 Speaker 1: blip on one of them, if it's a true gravitational wave, 481 00:31:26,240 --> 00:31:28,440 Speaker 1: you should also get a blip on the other one. 482 00:31:28,840 --> 00:31:31,600 Speaker 1: And because gravitational waves move at the speed of light, 483 00:31:32,160 --> 00:31:35,400 Speaker 1: there should be a slight difference in time when both 484 00:31:35,440 --> 00:31:40,280 Speaker 1: detectors pick up on this gravitational wave, somewhere right around 485 00:31:40,400 --> 00:31:43,680 Speaker 1: ten milliseconds or less. In the case of the one 486 00:31:43,760 --> 00:31:47,840 Speaker 1: that was detected back in the fall of twenty fifteen 487 00:31:47,880 --> 00:31:52,800 Speaker 1: but not announced until twenty sixteen, it hit the Louisiana 488 00:31:52,960 --> 00:31:58,080 Speaker 1: detector first, and seven milliseconds later it hit the Washington detector, 489 00:31:59,000 --> 00:32:02,120 Speaker 1: So that is indicative of something like a gravitational wave 490 00:32:02,160 --> 00:32:04,920 Speaker 1: as opposed to some local event that would have caused 491 00:32:04,960 --> 00:32:07,960 Speaker 1: interference and created a false positive. If an earthquake had 492 00:32:08,000 --> 00:32:13,360 Speaker 1: happened in Washington, then the facility may may have picked 493 00:32:13,400 --> 00:32:16,160 Speaker 1: something up, but you wouldn't expect to see it in 494 00:32:16,200 --> 00:32:20,240 Speaker 1: Louisiana because it was a localized event. Same thing is 495 00:32:20,240 --> 00:32:23,880 Speaker 1: true if something had happened in Louisiana. So by seeing 496 00:32:23,960 --> 00:32:28,040 Speaker 1: it happen at both within this ten millisecond timeframe meant 497 00:32:28,120 --> 00:32:31,720 Speaker 1: that it was a very good candidate for a gravitational 498 00:32:31,760 --> 00:32:36,720 Speaker 1: wave passing through. And that's exactly what happened. It was 499 00:32:36,840 --> 00:32:39,440 Speaker 1: a home run in the first ending of the game, 500 00:32:39,760 --> 00:32:42,360 Speaker 1: or even really the first at bat of the game. 501 00:32:42,400 --> 00:32:45,040 Speaker 1: It's like your first player steps up on the first 502 00:32:45,120 --> 00:32:48,280 Speaker 1: day of baseball and knocks a home run and that 503 00:32:48,440 --> 00:32:52,880 Speaker 1: defines the moment the season. Really, that's that's the equivalent 504 00:32:52,880 --> 00:32:56,920 Speaker 1: of what we saw here on a scientific basis. So 505 00:32:58,800 --> 00:33:01,960 Speaker 1: the other thing I want to talk about was how 506 00:33:02,040 --> 00:33:06,800 Speaker 1: LEGO tries to minimize the possibility of detecting a false 507 00:33:06,840 --> 00:33:09,440 Speaker 1: positive in the first place. So, yeah, false positives are 508 00:33:09,480 --> 00:33:11,720 Speaker 1: something that they worry about, and the fact that there 509 00:33:11,720 --> 00:33:14,760 Speaker 1: are two detectors helps minimize that. But even so, you 510 00:33:14,800 --> 00:33:18,200 Speaker 1: want to eliminate the possibility of a false positive so 511 00:33:18,240 --> 00:33:21,880 Speaker 1: that you're not constantly sifting through noise looking for a signal. 512 00:33:22,720 --> 00:33:24,920 Speaker 1: Do you want to minimize noise as much as possible. 513 00:33:25,800 --> 00:33:30,520 Speaker 1: So Lego does this through using combinations of active and 514 00:33:30,680 --> 00:33:36,920 Speaker 1: passive vibration reduction systems. One thing that they do is 515 00:33:36,920 --> 00:33:40,360 Speaker 1: they remove the air from the tubes. That is why 516 00:33:40,360 --> 00:33:43,960 Speaker 1: they're vacuum tubes. They remove the air for two reasons. One, 517 00:33:44,040 --> 00:33:47,560 Speaker 1: they don't want any sound passing through the chambers. Sound 518 00:33:47,640 --> 00:33:52,760 Speaker 1: could possibly interfere with the measurements. Sound would impact the mirrors, 519 00:33:53,400 --> 00:33:58,040 Speaker 1: and even a small impact would be enough to cause 520 00:33:58,120 --> 00:34:01,360 Speaker 1: a problem when you're measuring this laser. For one thing, 521 00:34:01,520 --> 00:34:04,960 Speaker 1: they're looking at distances when they're measuring the changes between 522 00:34:05,000 --> 00:34:08,560 Speaker 1: the two branches. You know, I mentioned that one's getting longer, 523 00:34:08,600 --> 00:34:12,600 Speaker 1: one's getting smaller. The distances they're looking at are very 524 00:34:12,719 --> 00:34:17,400 Speaker 1: very tiny. We're talking ten to the negative nineteenth power meters. 525 00:34:17,920 --> 00:34:20,080 Speaker 1: So again, you take the number ten, you move a 526 00:34:20,120 --> 00:34:24,280 Speaker 1: decimal place nineteen times to the left of that, and 527 00:34:24,400 --> 00:34:27,400 Speaker 1: you put meters at the end. That's the distance that 528 00:34:27,560 --> 00:34:32,520 Speaker 1: these lasers are are measuring the distortion and distance. So 529 00:34:32,560 --> 00:34:35,080 Speaker 1: it's very very very tiny, and something as simple as 530 00:34:35,120 --> 00:34:38,800 Speaker 1: sound could change that. So you can't have any sound 531 00:34:38,800 --> 00:34:42,000 Speaker 1: in these vacuum tubes, you've got to get the air out. Also, 532 00:34:42,040 --> 00:34:47,960 Speaker 1: air can absorb and scatter laser light, which would interfere 533 00:34:48,000 --> 00:34:50,000 Speaker 1: with the experiment as well, so you've got to get 534 00:34:50,000 --> 00:34:54,440 Speaker 1: air out. Now down to the vibration reduction systems. So 535 00:34:54,480 --> 00:34:57,719 Speaker 1: the active isolation system is meant to weed out the 536 00:34:57,760 --> 00:35:03,040 Speaker 1: majority of vibration, and it's active because it is actively 537 00:35:03,120 --> 00:35:07,719 Speaker 1: working against any vibration it encounters. You've got sensors that 538 00:35:07,880 --> 00:35:14,160 Speaker 1: detect vibration, they send commands to force actuators that move 539 00:35:14,520 --> 00:35:17,480 Speaker 1: in opposition to the vibration. So it's kind of like 540 00:35:17,640 --> 00:35:20,520 Speaker 1: noise canceling headphones. If you put on a pair of 541 00:35:20,560 --> 00:35:23,480 Speaker 1: noise canceling headphones, what they're supposed to do is pick 542 00:35:23,560 --> 00:35:27,080 Speaker 1: up any incoming sound and then generate sound waves that 543 00:35:27,120 --> 00:35:31,120 Speaker 1: are in direct opposition of the incoming sound, so that 544 00:35:31,160 --> 00:35:34,279 Speaker 1: you get a cancelation effect. That's the same thing that 545 00:35:34,360 --> 00:35:36,920 Speaker 1: these active systems are trying to do at LIGO, except 546 00:35:36,960 --> 00:35:39,600 Speaker 1: instead of it just being sound, it's really any vibration. 547 00:35:40,239 --> 00:35:42,479 Speaker 1: Although I guess you could argue that any vibration really 548 00:35:42,560 --> 00:35:46,120 Speaker 1: is sound, so it's kind of a moot point. But anyway, 549 00:35:46,160 --> 00:35:52,080 Speaker 1: they're actively trying to counteract that vibration. But then you've 550 00:35:52,080 --> 00:35:55,000 Speaker 1: got the passive system. This is the suspension system for 551 00:35:55,040 --> 00:35:59,400 Speaker 1: the mirrors, and this is the next step. So you've 552 00:35:59,560 --> 00:36:03,479 Speaker 1: eliminated a huge percentage of the vibration at this point, 553 00:36:03,520 --> 00:36:05,879 Speaker 1: but that's not good enough. You need to eliminate as 554 00:36:06,000 --> 00:36:08,240 Speaker 1: much as close to one hundred percent of the vibration 555 00:36:08,280 --> 00:36:11,880 Speaker 1: as you possibly can. So next we look at the 556 00:36:11,920 --> 00:36:16,160 Speaker 1: suspension system of Ligo's mirrors, and they are at the 557 00:36:16,200 --> 00:36:20,359 Speaker 1: base of a four pendulum system. Meaning imagine you've got 558 00:36:20,360 --> 00:36:24,800 Speaker 1: a string and it ends in a pendulum. A weight 559 00:36:25,000 --> 00:36:27,799 Speaker 1: a mass of some sort, and it has to be 560 00:36:27,840 --> 00:36:32,920 Speaker 1: a mass of significant size so that it will it'll 561 00:36:35,000 --> 00:36:39,359 Speaker 1: resist moving. It's the law of inertia. You know, an 562 00:36:39,360 --> 00:36:43,799 Speaker 1: object at rest tends to stay at rest, so it 563 00:36:43,840 --> 00:36:48,200 Speaker 1: will end up absorbing a lot of vibration and minimizing 564 00:36:48,239 --> 00:36:51,840 Speaker 1: it on the other end. So you've got that first pendulum, 565 00:36:51,920 --> 00:36:55,840 Speaker 1: that's pendulum number one. From that you suspend pendulum number two. 566 00:36:56,400 --> 00:37:00,440 Speaker 1: So already you're getting fewer vibrations because pendulum number one 567 00:37:00,560 --> 00:37:03,520 Speaker 1: is picking them up. What vibrations do manage to pass 568 00:37:03,560 --> 00:37:05,919 Speaker 1: through start to get picked up by pendulum number two, 569 00:37:06,880 --> 00:37:10,279 Speaker 1: and again the law of inertia means that it will 570 00:37:10,360 --> 00:37:12,880 Speaker 1: dampen a lot of that vibration. Then you've got pendulum 571 00:37:13,000 --> 00:37:16,320 Speaker 1: number three, and then beneath that you finally have the mirror, 572 00:37:16,360 --> 00:37:19,719 Speaker 1: which is forty kilograms or about eighty eight pounds worth 573 00:37:19,719 --> 00:37:25,000 Speaker 1: of mirror. And hopefully, after the active impassive systems have 574 00:37:25,120 --> 00:37:27,720 Speaker 1: all taken care of the vibration, nothing else is getting 575 00:37:27,760 --> 00:37:30,399 Speaker 1: to that mirror. By the way, you can actually test 576 00:37:30,440 --> 00:37:35,120 Speaker 1: this out yourself, if you like, by getting four strings 577 00:37:35,160 --> 00:37:38,520 Speaker 1: that are all equal length, and some washers, some nice 578 00:37:38,560 --> 00:37:42,000 Speaker 1: heavy washers. Tie a washer at the end of the 579 00:37:42,080 --> 00:37:47,719 Speaker 1: string of the first string. Then tie a washer so 580 00:37:47,760 --> 00:37:50,839 Speaker 1: that one end of the string connects to washer number one, 581 00:37:51,160 --> 00:37:53,160 Speaker 1: one end of the string connects to washer number two, 582 00:37:53,840 --> 00:37:55,640 Speaker 1: and so on and so forth. And if you hold 583 00:37:55,680 --> 00:37:59,440 Speaker 1: it up and you start shaking your hand holding the string, 584 00:38:00,200 --> 00:38:03,239 Speaker 1: notice that the washer at the top moves more than 585 00:38:03,280 --> 00:38:06,359 Speaker 1: the second washer, which moves more than the third, And 586 00:38:06,400 --> 00:38:08,000 Speaker 1: by the time you get down to the fourth one, 587 00:38:08,200 --> 00:38:10,840 Speaker 1: it's not moving much at all because it's been the 588 00:38:10,960 --> 00:38:14,719 Speaker 1: vibrations have been dampened by the previous pendulums. That's the 589 00:38:14,760 --> 00:38:19,440 Speaker 1: principle of this passive system. So that helps eliminate a 590 00:38:19,440 --> 00:38:23,680 Speaker 1: lot of that vibration. Without those dampening systems in place, 591 00:38:23,719 --> 00:38:26,399 Speaker 1: the two LIGO detectors would be picking up a lot 592 00:38:26,400 --> 00:38:30,239 Speaker 1: of noise, and since we're still not really sure how 593 00:38:30,239 --> 00:38:34,000 Speaker 1: often gravitational waves pass through the Earth, that would be 594 00:38:34,000 --> 00:38:37,360 Speaker 1: a problem now. Between two thousand and two and twenty 595 00:38:37,520 --> 00:38:39,800 Speaker 1: and ten, with the early version of LEGO, they didn't 596 00:38:39,800 --> 00:38:43,880 Speaker 1: pick up any gravitational waves at all, which we think 597 00:38:44,680 --> 00:38:48,960 Speaker 1: is because the detectors weren't sensitive enough. We think that's 598 00:38:48,960 --> 00:38:54,160 Speaker 1: the reason, but an alternative reason could be that gravitational 599 00:38:54,200 --> 00:38:56,799 Speaker 1: waves aren't as frequent as we think they are, that 600 00:38:56,880 --> 00:38:59,719 Speaker 1: they don't pass through the Earth as frequently as we 601 00:39:00,160 --> 00:39:04,400 Speaker 1: otherwise believe. However, the opposite could be true. We could 602 00:39:04,600 --> 00:39:08,960 Speaker 1: have way more gravitational waves passing through Earth than we 603 00:39:09,320 --> 00:39:12,600 Speaker 1: had anticipated. Some of them may be so faint that 604 00:39:12,680 --> 00:39:15,839 Speaker 1: even this advanced LIGO system cannot pick it up. There 605 00:39:15,840 --> 00:39:19,359 Speaker 1: are already plans to upgrade LIGO again, and there are 606 00:39:19,400 --> 00:39:24,560 Speaker 1: other LIGO observatory systems that will that are in development 607 00:39:24,600 --> 00:39:30,440 Speaker 1: now that will also listen in for gravitational waves. And 608 00:39:30,600 --> 00:39:33,000 Speaker 1: listen tends to be the way most people refer to it, 609 00:39:33,080 --> 00:39:39,080 Speaker 1: like you're listening for this universal vibration moving through the Earth. 610 00:39:40,480 --> 00:39:44,360 Speaker 1: So because it was only a few days after they 611 00:39:44,560 --> 00:39:47,520 Speaker 1: came online, a lot of people are thinking that gravitational 612 00:39:47,560 --> 00:39:51,879 Speaker 1: waves are probably fairly common. Otherwise, it was just extraordinarily 613 00:39:51,960 --> 00:39:55,040 Speaker 1: lucky that we picked it up just days after the 614 00:39:55,480 --> 00:39:59,680 Speaker 1: observatory was online. Again, the one that we did pick 615 00:39:59,719 --> 00:40:03,360 Speaker 1: up one point three billion light years away, which means 616 00:40:03,400 --> 00:40:06,000 Speaker 1: that the event happened one point three billion years ago. 617 00:40:06,080 --> 00:40:09,560 Speaker 1: That event being two black holes colliding with one another 618 00:40:09,640 --> 00:40:16,440 Speaker 1: to form a solitary black hole mass. In the process, 619 00:40:16,520 --> 00:40:21,880 Speaker 1: it vaporized about three solar masses worth of mass I guess, 620 00:40:22,800 --> 00:40:26,719 Speaker 1: which is a huge amount to think about being converted 621 00:40:26,760 --> 00:40:30,880 Speaker 1: into energy, and the gravitational waves emanated from there at 622 00:40:30,880 --> 00:40:34,720 Speaker 1: the speed of light. So one point three billion years later, Earth, 623 00:40:34,800 --> 00:40:37,799 Speaker 1: which was one point three billion light years away, picked 624 00:40:37,880 --> 00:40:42,040 Speaker 1: them up. So in a way, it was incredibly lucky. 625 00:40:42,120 --> 00:40:46,480 Speaker 1: But if this happens more frequently than we originally believed, 626 00:40:47,040 --> 00:40:50,080 Speaker 1: we might see that this is not an uncommon event. 627 00:40:50,600 --> 00:40:54,080 Speaker 1: It's very possible that there are things we cannot see 628 00:40:54,160 --> 00:40:59,640 Speaker 1: in the universe that create gravitational waves. So in other words, 629 00:40:59,640 --> 00:41:03,120 Speaker 1: it's off that does not give off electromagnetic radiation at all, 630 00:41:03,719 --> 00:41:06,399 Speaker 1: but it does create gravitational waves, meaning that we now 631 00:41:06,480 --> 00:41:09,520 Speaker 1: have the capacity to detect things that otherwise would have 632 00:41:09,560 --> 00:41:13,120 Speaker 1: remained completely undetectable by us. So one of the many 633 00:41:13,200 --> 00:41:17,480 Speaker 1: reasons why this discovery is so exciting, it opens up 634 00:41:17,719 --> 00:41:21,400 Speaker 1: brand new science. It creates a new discipline of science, 635 00:41:21,400 --> 00:41:25,960 Speaker 1: gravitational astronomy, which can really get going now because it's 636 00:41:26,080 --> 00:41:30,920 Speaker 1: not that different from when the telescope was invented. Before 637 00:41:30,960 --> 00:41:34,359 Speaker 1: the telescope, astronomy was pretty limited. You could map out 638 00:41:34,440 --> 00:41:38,239 Speaker 1: astrological bodies when you were way back in the day 639 00:41:38,280 --> 00:41:41,920 Speaker 1: before the science of astronomy had really gotten going. Once 640 00:41:41,960 --> 00:41:45,360 Speaker 1: you started figuring out the difference between mythology and science, 641 00:41:45,440 --> 00:41:49,600 Speaker 1: then astronomy really takes over. You could map out where 642 00:41:49,600 --> 00:41:52,759 Speaker 1: these different bodies go. You could figure out which ones 643 00:41:52,800 --> 00:41:56,959 Speaker 1: are must be planets versus stars, but you couldn't really 644 00:41:58,040 --> 00:42:01,040 Speaker 1: gather a lot more information than that. You could still 645 00:42:01,080 --> 00:42:04,840 Speaker 1: get an impressive amount of data just from observing with 646 00:42:04,840 --> 00:42:08,600 Speaker 1: the naked eye, but the telescope opened up a whole 647 00:42:08,640 --> 00:42:13,840 Speaker 1: new world of study, and this gravitational wave detector system 648 00:42:13,920 --> 00:42:17,480 Speaker 1: has opened up a similar, all new world that was 649 00:42:17,719 --> 00:42:23,399 Speaker 1: not accessible by us until this year really late last year, 650 00:42:23,480 --> 00:42:27,959 Speaker 1: late twenty fifteen, So we might end up discovering things 651 00:42:28,000 --> 00:42:31,240 Speaker 1: that we've never been able to observe before. Will also 652 00:42:31,560 --> 00:42:34,800 Speaker 1: likely be able to study all sorts of cool stuff, 653 00:42:34,840 --> 00:42:38,040 Speaker 1: like how fast is the universe expanding, how much dark 654 00:42:38,160 --> 00:42:41,680 Speaker 1: energy is in our universe. We might learn more about 655 00:42:41,680 --> 00:42:47,640 Speaker 1: black holes already. The gravitational wave detected by LIGO has 656 00:42:47,719 --> 00:42:52,400 Speaker 1: given us the strongest direct evidence of black holes. I 657 00:42:52,440 --> 00:42:55,360 Speaker 1: guess I should say indirect evidence because it's the gravity 658 00:42:55,400 --> 00:43:00,040 Speaker 1: waves generated by the black holes. But not that we 659 00:43:00,320 --> 00:43:03,360 Speaker 1: ever doubted the existence of black holes, but this is 660 00:43:03,440 --> 00:43:07,920 Speaker 1: yet more evidence in support of them. So it's really 661 00:43:08,280 --> 00:43:11,680 Speaker 1: an exciting time. We could end up learning all sorts 662 00:43:11,680 --> 00:43:14,359 Speaker 1: of stuff, stuff that we can't even anticipate right now, 663 00:43:14,880 --> 00:43:17,880 Speaker 1: and that's why it's such a big deal. I also 664 00:43:17,880 --> 00:43:21,200 Speaker 1: think that LEGO is just an incredibly elegant way of 665 00:43:21,440 --> 00:43:25,080 Speaker 1: detecting something that otherwise is impossible for us to see 666 00:43:25,200 --> 00:43:30,240 Speaker 1: or feel or experience, and it's incredibly simple, at least 667 00:43:30,360 --> 00:43:33,640 Speaker 1: on the principle of it. The technology itself is very 668 00:43:33,640 --> 00:43:36,120 Speaker 1: complicated because it has to be so sensitive to detect 669 00:43:36,160 --> 00:43:41,000 Speaker 1: these very tiny changes in distance and time. But the 670 00:43:41,040 --> 00:43:45,640 Speaker 1: principle behind it is elegant, and I mean, you don't 671 00:43:45,640 --> 00:43:48,120 Speaker 1: get much more simple than a ninety degree angle. That's 672 00:43:48,280 --> 00:43:52,680 Speaker 1: pretty bare bones there, but a very clever way of 673 00:43:52,719 --> 00:43:56,880 Speaker 1: detecting something that Einstein believed was going to be beyond 674 00:43:56,960 --> 00:44:02,600 Speaker 1: our ability to ever experience. So now we have a 675 00:44:02,640 --> 00:44:06,680 Speaker 1: revolutionary new way to examine the universe. We have no 676 00:44:06,719 --> 00:44:09,239 Speaker 1: way of knowing what sort of stuff we might learn 677 00:44:09,400 --> 00:44:13,520 Speaker 1: as a result, which is incredibly exciting. And it's all 678 00:44:13,600 --> 00:44:17,560 Speaker 1: due to some lasers, some beam splitters, and some mirrors. 679 00:44:17,600 --> 00:44:20,800 Speaker 1: And since we're already looking at lots of different organizations 680 00:44:21,239 --> 00:44:27,360 Speaker 1: building their own LIGO observatories and also increasing the capacity 681 00:44:27,480 --> 00:44:32,800 Speaker 1: or at least the sensitivity of the current LEGO system, 682 00:44:33,040 --> 00:44:37,279 Speaker 1: who knows what we're going to see next. I hope 683 00:44:37,320 --> 00:44:41,600 Speaker 1: you enjoyed that classic episode on HOWLEGO works way back 684 00:44:41,640 --> 00:44:44,400 Speaker 1: in twenty sixteen. I should definitely do an update on 685 00:44:44,480 --> 00:44:47,000 Speaker 1: that and talk more about the sort of things we've 686 00:44:47,080 --> 00:44:51,000 Speaker 1: learned since the detection of gravitational waves and how that 687 00:44:51,120 --> 00:44:57,040 Speaker 1: has affected science. But if you have suggestions for things 688 00:44:57,080 --> 00:44:59,439 Speaker 1: I should cover in future episodes of tech Stuff, I'd 689 00:44:59,440 --> 00:45:01,399 Speaker 1: love to hear. There are a couple of different ways 690 00:45:01,440 --> 00:45:03,759 Speaker 1: you can do that. You can download the iHeartRadio app. 691 00:45:04,000 --> 00:45:06,239 Speaker 1: It's free to downloads free to us. You can just 692 00:45:06,360 --> 00:45:08,480 Speaker 1: navigate over to tech Stuff. Put tech Stuff in that 693 00:45:08,520 --> 00:45:11,040 Speaker 1: little search field. It'll take it to the podcast page. 694 00:45:11,280 --> 00:45:13,640 Speaker 1: You'll see a little microphone icon. If you click on that, 695 00:45:13,680 --> 00:45:16,720 Speaker 1: you can leave a voice message up thirty seconds in length, 696 00:45:17,120 --> 00:45:19,680 Speaker 1: and I love hearing from y'all, so feel free to 697 00:45:19,680 --> 00:45:22,680 Speaker 1: do that. If you would prefer to send me something 698 00:45:22,800 --> 00:45:25,959 Speaker 1: via text, well, you can go over to Twitter and 699 00:45:26,239 --> 00:45:29,640 Speaker 1: use send a message to the handled text Stuff HSW 700 00:45:29,920 --> 00:45:32,239 Speaker 1: that's our handle, and let me know what it is 701 00:45:32,280 --> 00:45:34,160 Speaker 1: you would like me to do. Cover in future episodes 702 00:45:34,200 --> 00:45:37,760 Speaker 1: of tech Stuff and I'll talk to you again really soon. 703 00:45:43,760 --> 00:45:48,440 Speaker 1: Text Stuff is an iHeartRadio production. For more podcasts from iHeartRadio, 704 00:45:48,760 --> 00:45:52,439 Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen 705 00:45:52,480 --> 00:45:53,560 Speaker 1: to your favorite shows.