Speaker 1: Brought to you by Toyota. Let's go places. Welcome to
Speaker 1: Forward Thinking. Hey there, and welcome to Forward Thinking, the
Speaker 1: podcast that looks at the future and says white about
Speaker 1: I'm Jonathan Strickland, I'm Lauren voc Obama, and I'm Joe McCormick.
Speaker 1: And today, you guys aren't going to be able to
Speaker 1: depend on me to be my normal plucky self because
Speaker 1: I've got kind of a bad cold. So I'm sorry
Speaker 1: that I'm even talking in your general direction right now,
Speaker 1: but I suppose the show must go on. Well yeah,
Speaker 1: and Joe, it's it's kind of it's kind of fitting
Speaker 1: that that you are a little out of play here,
Speaker 1: right because we're going to revisit a topic that Lauren
Speaker 1: and I talked about, gravitational waves, and you weren't here
Speaker 1: for that episode. God, just act like I'm not here.
Speaker 1: So yeah, so mentally you're you're again not in the room.
Speaker 1: You're on vacation. You're always wonderful and find an excellent Yeah,
Speaker 1: I'm sure that you'll be a joy as always. But hey,
Speaker 1: gravitational waves, this was some big this month. Yeah, huge news.
Speaker 1: And actually it's funny because the discovery happened in two
Speaker 1: thousand and fifteen. But as is the case with any
Speaker 1: really you know, careful, responsible scientific inquiry, it took some
Speaker 1: time for scientists to verify the information the data they
Speaker 1: had gathered before they actually announced what they had found.
Speaker 1: You know, it did, but I don't know if you
Speaker 1: all noticed it, if you follow the the I don't know,
Speaker 1: science writers on Twitter or or the science press in general.
Speaker 1: There were several rounds of rumors flaring up where some
Speaker 1: prominent physicists or cosmologists would sort of like drop a
Speaker 1: hint saying like, I think they found gravity waves. Yeah,
Speaker 1: I know, you're gonna you're gonna get out of your
Speaker 1: red pin about that a little bit. Yeah, And and
Speaker 1: so somebody would print a story about that, and the
Speaker 1: rumor mill would flare up, and then it would all
Speaker 1: end with well, I guess we'll just have to wait
Speaker 1: until they announced their findings and see what happened. But
Speaker 1: it turned out that the rumors were in this case true, right.
Speaker 1: There was a very very strong, very well established piece
Speaker 1: of evidence for gravitational waves in the universe. Yes, a
Speaker 1: a detection that appears to be pretty much air tight.
Speaker 1: So uh, And that was announced on February eleven. We
Speaker 1: were all eagerly waiting for the announcement. In fact, many
Speaker 1: of us were following it live as it was happening. Joe,
Speaker 1: you were tweeting about it live as it was happening.
Speaker 1: As I recall, I think I just I retweeted. Some
Speaker 1: people got you. I wasn't. I wasn't live tweeting, and
Speaker 1: you were tweeting. You weren't undead? Are you undead? Is
Speaker 1: this what this called? Isomie a little bit undead? I
Speaker 1: hope you all both brought across well at any rate.
Speaker 1: The last zombies. Okay, go ahead if you if you're
Speaker 1: really cross with a zombie, they take note. So we
Speaker 1: originally talked about gravitational waves back in September two thousand
Speaker 1: and fourteen, and in that conversation we were talking specifically
Speaker 1: about BICEP two, which is a telescope that's in the Antarctic. Yeah,
Speaker 1: and if you remember some time vaguely in the past,
Speaker 1: either this podcast or just other general news announcements a
Speaker 1: few years ago, and you're saying, like, wait, I thought
Speaker 1: they already discovered gravitational waves. There is a reason you're
Speaker 1: remembering that. Yeah. Yeah, Well they said, hey, guys, I
Speaker 1: think that we we we think that we discovered gravitational waves.
Speaker 1: This is so great. And what they actually discovered was
Speaker 1: spacedest yeah, or at least space dust was enough of
Speaker 1: a factor to throw the results into serious doubt. But
Speaker 1: we'll talk about that a little bit more later in
Speaker 1: the podcast. This time, we're going to really be focusing
Speaker 1: on what Lego found. Uh Ligo is a pair of observatories,
Speaker 1: and we'll talk more about those in a minute. But
Speaker 1: before we get into any of that, perhaps it's best
Speaker 1: to actually take some time to talk about what gravitational
Speaker 1: waves are in the first place, and to understand that
Speaker 1: you've gotta look back in history, all the way back
Speaker 1: to nineteen sixteen, which is when Albert Einstein published his
Speaker 1: his theory of general relativity, had been working on it
Speaker 1: since nineteen o five. Right, So, Alfred B. Iimstein was
Speaker 1: out on a train one day, hurling axes out the
Speaker 1: window at passing herds of buffalo and he never give
Speaker 1: you cold medication before a podcast. And he noticed that
Speaker 1: as he tossed each ax, it arcd towards the ground
Speaker 1: instead of flying off in an infinite direction in which
Speaker 1: he threw it. So why does that happen. Alright, ignoring
Speaker 1: everything that Joe just said, Here's here's what Einstein was
Speaker 1: was considering. He had been really thinking hard about the
Speaker 1: nature of the universe. Uh. This was part mathematics, part philosophy,
Speaker 1: part just uh just using logic to its inevitable conclusion.
Speaker 1: And it was incredible. The theory he came up with,
Speaker 1: it was it was phenomenal, and not just phenomenal. But
Speaker 1: over the years, so much of that theory has proven
Speaker 1: to be accurate to what we see in reality. That
Speaker 1: you know, we we just keep on supporting the various
Speaker 1: predictions that were made, and gravitational waves were one of
Speaker 1: the predictions made in the theory of general relativity. Uh.
Speaker 1: He he had argued that that the universe is made
Speaker 1: up of uh space time continuum. You've probably heard that
Speaker 1: if you've ever watched any Star Trek, you've heard about
Speaker 1: the space time continuum. But the spacetime continuum is is
Speaker 1: sort of this idea of space and time together forming
Speaker 1: kind of a fabric of the universe and matter or
Speaker 1: to be really just just to to talk it in
Speaker 1: the terms he used, mass can change, can can warp spacetime.
Speaker 1: In fact, it does warp spacetime. The presence of matter
Speaker 1: warps spacetime. So the most common analogy that you tend
Speaker 1: to see is that imagine you've got a trampoline and
Speaker 1: you put a bowling ball on the trampoline. It ends
Speaker 1: up making a dimple in the trampoline. It sinks down
Speaker 1: where the bowling ball is resting that here here, the
Speaker 1: trampoline being spacetime and the bowling ball being say a star,
Speaker 1: yeah exactly, let's let's a star, black hole, anything that's
Speaker 1: got a lot of mass, and uh you that would
Speaker 1: show you how the trampoline warps around the bowling ball,
Speaker 1: like spacetime warps around an object of great mass. Keeping
Speaker 1: in mind, of course, that we're using more or less
Speaker 1: a two dimensional representation to talk about three dimensional concept.
Speaker 1: But it's really hard to imagine a three dimensional concept. Really, Yeah,
Speaker 1: that's true, because you're talking about time. It is true.
Speaker 1: But then if you were to take a marble, let's say,
Speaker 1: and roll it across the trampoline. Now, if it were
Speaker 1: if there were no bowling ball on it, the marble
Speaker 1: would just roll from one side to the other, assuming
Speaker 1: that you're on level ground and all that. But with
Speaker 1: the bowling ball. There, it's gonna start spiraling inward towards
Speaker 1: the bowling ball. And Einstein argued that what we see
Speaker 1: with gravity, with with gravitational pull between like a star
Speaker 1: and a planet, or even the center of a galaxy
Speaker 1: and all of the star systems, that's how they behave
Speaker 1: they move in that same spiral. And uh So, now
Speaker 1: one difference you might observe is that you think, hey,
Speaker 1: well if I did that on a trampoline, and probably
Speaker 1: marble would probably only spiral around the bowling ball three
Speaker 1: or four times before it crashed into it. There, I
Speaker 1: would guess the difference is going to be in this
Speaker 1: example friction between the marble and the trampoline. We also
Speaker 1: speak and orbits in space being you know, almost negligible
Speaker 1: amounts of friction. Yeah, that's definitely, that's definitely the case.
Speaker 1: It helps. So what we see here is that spacetime
Speaker 1: curves around objects and then be building upon that. Uh
Speaker 1: Einstein said, if you have a large mass undergo a
Speaker 1: violent change, either it changes shape or it changes its
Speaker 1: motion in some way in a dramatic way, it creates
Speaker 1: these ripples in space time that propagate outward at the
Speaker 1: speed of light. And these are gravitational waves. Um. So
Speaker 1: it's actual ripples in space time itself, and it's kind
Speaker 1: of like an electromagnetic wave, and that it moves at
Speaker 1: that speed of light, but unlike electromagnetic waves, it can't
Speaker 1: be absorbed and it can't be scattered. Yeah, it behaves
Speaker 1: in that way, more like a sound wave. Yeah, exactly.
Speaker 1: So if you think of sound waves, where when you
Speaker 1: hear a sound, what you're actually hearing is the motion
Speaker 1: of air molecules. Those air molecules are being compressed by
Speaker 1: an oncoming wave and then they expand again afterward. It's
Speaker 1: very similar to that, except we're talking about the fabric
Speaker 1: of reality itself. Now, let me play Jonathan for a
Speaker 1: second and be pedantic. It wouldn't necessarily have to be
Speaker 1: air molecules, would it be whatever medium that the sound
Speaker 1: is traveling through. That's true. Yeah, it could be solid
Speaker 1: wood and it's still has um and we should we
Speaker 1: should put in that Einstein himself wasn't entirely sure about
Speaker 1: this gravitational wave stuff. He kind of flip flopped on
Speaker 1: it a few times, but always came back around to
Speaker 1: support it. So I think that he himself would be
Speaker 1: sort of tickled that we a came up with a
Speaker 1: way to detect them and be have actually detected Yeah.
Speaker 1: I think he would be flabber guested because I the
Speaker 1: impression I get is that Einstein was fairly certain because
Speaker 1: the nature of gravitational waves, they would be undetectable. There
Speaker 1: there'll be no way to directly observe them because they
Speaker 1: are invisible, there's nothing. They're not like electromagnetic radiation, where
Speaker 1: you've got an actual visible spectrum. Um. So I think
Speaker 1: that would have really shocked him that we had come
Speaker 1: up with a really clever way of detecting the presence
Speaker 1: of gravitational waves. Now, Jonathan, why is it that you
Speaker 1: have a bone to pick with anybody who calls this
Speaker 1: most recent discovery the discovery of gravity waves? Well, because
Speaker 1: it's wrong. So gravity waves you told me all about
Speaker 1: the wrongness. Gravity and gravitational are two different things. With
Speaker 1: a gravitational wave, you are talking about this ripple through
Speaker 1: space time that travels outward at the speed of light.
Speaker 1: With gravity waves, you're talking about a wave that exists
Speaker 1: due to gravity. It's something that you would find on
Speaker 1: a planet, either in some sort of fluid system, whether
Speaker 1: it's an atmosphere or like a body of water. So, um,
Speaker 1: let's say you've got an ocean and you've got wind
Speaker 1: blowing across the surface of that ocean, it starts to
Speaker 1: disturb the water. Gravity is pulling down on the surface
Speaker 1: of that water, and uh, waters buoyancy is acting in
Speaker 1: opposition to gravity, and that combined with the wind, creates
Speaker 1: a wind driven um wave. That would be a gravity wave.
Speaker 1: It's a wave that exists because gravity is there. If
Speaker 1: there were no gravity through would even be a body
Speaker 1: of water there. Uh. That is a gravity wave totally
Speaker 1: different from a gravitational wave, just a physical wave that
Speaker 1: you can observe through some form of fluidic system. And
Speaker 1: so if you ever hear someone say gravity waves of
Speaker 1: gravitational wave as a matter of shorthand they're technically being incorrect,
Speaker 1: you should probably find a polite way to say, maybe
Speaker 1: you meant gravitational wave, or you could be like me,
Speaker 1: and there's no polite way to say that. Yeah, I
Speaker 1: gave up on being polite years ago, so I just
Speaker 1: tried to caution other people not to make the same
Speaker 1: choices I made. Um. But yeah, there's some some other
Speaker 1: interesting things about gravitational waves. They pass through stuff. So
Speaker 1: like we said, yeah, yeah, they don't act like electromagnetic waves. Yeah,
Speaker 1: they don't get absorbed or reflected, so they just poop
Speaker 1: keep on going. So if you've got, for example, a
Speaker 1: planet between you and electromagnetic radiation such as light from
Speaker 1: the Sun, you will experience in eclipse because the planet
Speaker 1: blocks it. But it will not block these gravity waves exactly, won't.
Speaker 1: It won't eclipse the the movement of waves toward you.
Speaker 1: The waves will get weaker as they propagate out over
Speaker 1: distance though, yes, and uh So if you're talking about
Speaker 1: a gravitational wave that has you know, has happened because
Speaker 1: of some massive event that's a billion light years away,
Speaker 1: they are very very faint by the time they get
Speaker 1: to Earth. Uh And that also leads to why they've
Speaker 1: been so tricky to detect. Not only are they invisible,
Speaker 1: but they're not very strong. So we have to look
Speaker 1: for gravitational waves that have been caused by really really
Speaker 1: big events, like in the case of the one that
Speaker 1: Ligo detected in September two thousand fifteen, it was the
Speaker 1: collision of two black holes. It's a pretty big event.
Speaker 1: Others could be two neutron stars that are orbiting one
Speaker 1: another rapidly, which would create kind of an oscillating and
Speaker 1: continuous a series of gravitational waves. Um or it could
Speaker 1: be like a supernova exploding that to do it. A
Speaker 1: big bang that would do it too. In fact, that
Speaker 1: was what my step two was looking for, was the
Speaker 1: evidence of gravity waves from the era of the Big Bang.
Speaker 1: I just caught you in it. What, oh man, I
Speaker 1: I I stand correct, I sit corrected here in to eat,
Speaker 1: Thank you well, and as soon as I get the
Speaker 1: foot out of my mouth, I will start chewing upon
Speaker 1: the hat. Yes, gravitational wave not gravity wave. No, it's
Speaker 1: true that they have been so difficult to detect and
Speaker 1: that we've had to come up with very interesting methods
Speaker 1: of trying to detect them, involving laser interferometry. Yeah. So
Speaker 1: here's here's something that's really cool about a gravitational wave
Speaker 1: because it's this ripple in space time. It actually is
Speaker 1: a small you can think of it like a small
Speaker 1: fold in spacetime, right, and that means it can actually
Speaker 1: change the distance between two points by compressing that distance
Speaker 1: or expanding it like a rubber band. So you've got
Speaker 1: like a piece of elastic h or if you prefer,
Speaker 1: you know, just just imagine that, Um, Joe, you and
Speaker 1: I are standing across a football field from one another.
Speaker 1: You're on one end zone. I'm in the other end zone.
Speaker 1: Their en zones in football, right, I'm just looking for
Speaker 1: There's no help from the one with the oblong spheroid, right, Yes,
Speaker 1: that's it. Or you know, a soccer field if you prefer,
Speaker 1: But then you know where at either end gravitational wave
Speaker 1: passes through. Let's say it's a massive gravitational wave, something
Speaker 1: way bigger than we would ever actually observe here on Earth.
Speaker 1: What would appear to happen is that Joe and I
Speaker 1: from our perspectives, it would look like we got closer
Speaker 1: and then further apart, and then closer and then further apart,
Speaker 1: without ever taking a step in either direction. That the are,
Speaker 1: the world itself has compressed and expanded around us because
Speaker 1: of this fold in spacetime that's passing through, which sounds
Speaker 1: like some serious like matrix style stuff. But either fortunately
Speaker 1: or unfortunately, depending on how you know, stable you like
Speaker 1: your reality, that's that's that kind of dramatic change is
Speaker 1: not what we observe from gravitational waves, right, Not at all,
Speaker 1: not even remotely in the same football field as it were.
Speaker 1: Uh No, Instead, if you were to have something like
Speaker 1: a supernova explosion, and I should say an asymmetric supernova
Speaker 1: explosion for reasons I don't understand, a symmetrical supernova does
Speaker 1: not a supernova explosion does not generate gravitational waves. I
Speaker 1: don't know why I was reading it trying to find
Speaker 1: more information, but it got to a point where the
Speaker 1: astrophysics got way too complicated for me to understand. However,
Speaker 1: what I do understand is that if there were a
Speaker 1: supernova explosion in our galaxy in the Milky Way, the
Speaker 1: gravitational waves generated from that would only be powerful enough
Speaker 1: to change the distance between Earth and the Sun by
Speaker 1: the diameter of one hydrogen atom. That's how much it
Speaker 1: would oscillate. Oh yeah, okay, you probably would notice. So
Speaker 1: this is like a princess and the p kind of thing,
Speaker 1: isn't it. Yeah, definitely, definitely on that level. Obviously, we
Speaker 1: need to build a more sensitive princess. That's that's the
Speaker 1: you know, that's entirely the plot. Yeah, yeah, we're about
Speaker 1: a mattress. You know, it's all musical about that. Oh
Speaker 1: I didn't build a robot princess, any number of mattress.
Speaker 1: They just they just uh collued to make her uncomfortable
Speaker 1: so that she she complains about the the lumpiness of
Speaker 1: the mattress, and it turns out that there's not just
Speaker 1: a p under there. There's also a suit of armor
Speaker 1: and a shield. Spoiler alert for any of you who
Speaker 1: are really looking forward to what's upon a mattress. Yeah.
Speaker 1: But but but I suppose they did kind of create
Speaker 1: like a laser princess. So yeah, but we'll get into that.
Speaker 1: So anyway, So so I just mentioned that if you're
Speaker 1: looking at the Earth and the Sun, you're talking about
Speaker 1: the differ prints of the diameter of an hydrogen atom
Speaker 1: in the distance, which is incredible to think about. But
Speaker 1: that that change, that difference in distance gets smaller as
Speaker 1: you get two smaller scales. So let's talk about if
Speaker 1: you were on Earth and trying to measure this, because
Speaker 1: this gets to why it has been so challenging to
Speaker 1: detect gravitational waves here on Earth. Okay, don't use a
Speaker 1: football field analogy. What about the need to how about
Speaker 1: the beginning and end of the line for space Mountain.
Speaker 1: That's a queue that goes like, yeah, that one already
Speaker 1: loops around back on itself in weird ways. Yeah, it's
Speaker 1: not really gonna work. No, I don't need to make
Speaker 1: that comparison. I was just to to establish the weirdness
Speaker 1: of what happens. But no, I wanted to just talk
Speaker 1: about the scale. So if you were talking about here
Speaker 1: on Earth and you're trying to measure that that change
Speaker 1: in reality, that change in distance because the spacetime continuum
Speaker 1: is being folded in this ripple. Uh. If you had
Speaker 1: two objects that are about a column butt are apart,
Speaker 1: the change in distance they would experience due to that
Speaker 1: gravitational wave would be thousands of the diameter of a proton.
Speaker 1: So take a sub atomic particle and go a teeny
Speaker 1: tiny fraction of the diameter of that subotomic particle, and
Speaker 1: that's how much difference in distance it would experience. Get
Speaker 1: out your your proton knife and your proton measuring set,
Speaker 1: and it turns out your ruler is not going to
Speaker 1: be terribly helpful in that case. So that is one
Speaker 1: of the reasons why it's been so incredibly challenging to
Speaker 1: detect the presence of a gravitational wave. And and we
Speaker 1: we've had a few leads, or if you prefer, a
Speaker 1: few false starts in detecting them throughout history. Back in
Speaker 1: nineteen sixty nine, University of Maryland physicist Joseph Weber created
Speaker 1: this this six foot aluminum cylinder that he claimed would
Speaker 1: act like an antenna for gravitational waves. He said that
Speaker 1: when such a wave hit the cylinder, it would ring
Speaker 1: like a tuning fork, but nobody else could replicate his results.
Speaker 1: It was a kind of neat looking device, though. There's
Speaker 1: actual video of this, and it look kind of like
Speaker 1: a mirrored two inside another tube, like there was like
Speaker 1: some sort of crazy physics disco going on inside there. Uh,
Speaker 1: or at least that's what I like to think. Back
Speaker 1: in nineteen seventy four, there are a pair of scientists
Speaker 1: in Puerto Rico who saw a binary pulsar system and
Speaker 1: they looked at the theory of general relativity, which predicted
Speaker 1: that such a system would gradually lose energy due to
Speaker 1: the too emitting gravitational waves. Some of its energy would
Speaker 1: go into creating these gravitational waves, and because you have
Speaker 1: a system losing energy, it would start to lose speed.
Speaker 1: And so they said, well, based upon this prediction, we
Speaker 1: should observe this change in speed as long as we
Speaker 1: keep an eye on this binary pulsar system. So they
Speaker 1: tracked it for eight years. At the end of the
Speaker 1: eight year period, they said the behavior of the binary
Speaker 1: pulsar system was completely in line with the predictions from
Speaker 1: general relativity. He said, it is behaving precisely the way
Speaker 1: it would if, in fact, gravitational waves are reality. Therefore,
Speaker 1: this is in support of gravitational waves. And even since then,
Speaker 1: over the forty years of observations that have happened with
Speaker 1: this binary pulsar system, those predictions continued to be supported.
Speaker 1: So that was great, you know, indirect evidence of gravitational waves, saying, well,
Speaker 1: if they don't exist, something else must be happening for
Speaker 1: this system to slow down the way it is. But
Speaker 1: the thing that makes most sense is that Einstein was right.
Speaker 1: Then we move ahead quite a bit. Let's talk about
Speaker 1: BICEP two. Now, BICEP two was going a different way
Speaker 1: about looking for gravitational waves. They were specifically looking for
Speaker 1: evidence of UH that would support a hypothesis called cosmic inflation,
Speaker 1: and inflation is a big deal in physical cosmology today.
Speaker 1: This is I think most physical cosmologists look at inflation
Speaker 1: is very promising theory. Yeah, And the whole reason why
Speaker 1: we have this this idea in the first place is
Speaker 1: to explain why the universe appears the way it does,
Speaker 1: while also trying to reconcile that with the Big Bang theory.
Speaker 1: Because I'm not going to get too far into the
Speaker 1: weeds here, but the basically the hypothesis says that about
Speaker 1: ten to the negative thirty six seconds. So take a
Speaker 1: ten and then take a decimal point and move that
Speaker 1: thirty six places to the left. Get get that proton
Speaker 1: knife out again, did up a second, right, That's that's
Speaker 1: where you get down to the teeny tiny, tiny tiny
Speaker 1: fraction of a second to about ten to the negative
Speaker 1: thirty three or thirty second power seconds. So so in
Speaker 1: an instant, as far as we're concerned, into an instant, Yeah,
Speaker 1: that at that moment, that's when the universe underwent rapid expansion,
Speaker 1: far greater than the rate of expansion it currently is
Speaker 1: going through. And it's expanding fast today. Yeah. Actually, then
Speaker 1: it's picking up speed, which is a little uh, at
Speaker 1: least according to our measurements, it is picking up speed.
Speaker 1: But that's that's something that we hope gravitational waves will
Speaker 1: help us learn more about in the future at any rate.
Speaker 1: A scientist named Alan Gooth proposed a hypothesis to explain
Speaker 1: why the universe looks the way it does and stay
Speaker 1: in line with the Big Bang theory. It was kind
Speaker 1: of like, well, in order for us to be where
Speaker 1: we are now based upon the observations of the universe
Speaker 1: we have made so far, and in order for the
Speaker 1: Big Bang theory to make any sense whatsoever, there had
Speaker 1: to be this period of cosmic inflation or else. It
Speaker 1: just doesn't work out. The math doesn't work out. And
Speaker 1: in a way you could argue, all this is almost
Speaker 1: like a placeholder, except again, it's kind of like Einstein.
Speaker 1: It's using logic saying, well, we we know about this,
Speaker 1: we're pretty sure about this other thing. But in order
Speaker 1: for those two things to reconcile, this other, this third
Speaker 1: thing must have happened at some point. Yeah. Yeah, it's
Speaker 1: theoretically solving for X in this equation. Yeah, and if
Speaker 1: you fast forward three thousand years after the Big Bang,
Speaker 1: you then have the emergence of the cosmic microwave background
Speaker 1: or c MB. Now, this is a radiation that's sort
Speaker 1: of a fingerprint left over from the from the era
Speaker 1: after the Big Bang. It's from it's when the universe
Speaker 1: was still seeing birdies. Like in the cartoon, universe really
Speaker 1: wasn't seeing anything. It was so dense that even light
Speaker 1: couldn't pass through it at this point. Um, but it is.
Speaker 1: It's sort of the remnant of that era, and we
Speaker 1: can we can detect the cosmic microwave background. So BICEP
Speaker 1: two I didn't mention to se either. BICEP actually stands
Speaker 1: for background imaging of cosmic extra galactic polarization. Was looking
Speaker 1: for polarized cosmic microwave background radiation. The idea being that
Speaker 1: gravitational waves should have aligned certain segments of the CMB,
Speaker 1: so if you could detect that, then that would be
Speaker 1: indirect evidence of gravitational waves and therefore also indirect evidence
Speaker 1: of this cosmic inflation idea, because something as dramatic as
Speaker 1: cosmic inflation would have generated gravitational waves and they would
Speaker 1: have left their mark on something like the CNB, and
Speaker 1: they the team thought they found it. They actually thought
Speaker 1: they found it a couple of years before the news broke.
Speaker 1: They spent years trying to verify the information they found
Speaker 1: to make sure that they eliminated other possibilities. They went
Speaker 1: public with the UH the announcement I think March of
Speaker 1: two thousand fourteen, and it was September two thousand fourteen
Speaker 1: when other teams came out and said, we think it
Speaker 1: might be the presence of space dust that has at
Speaker 1: least complicated your findings, if not discredit it. Did them, Yeah,
Speaker 1: well yeah, and that's you know, they had opened up
Speaker 1: their research to that kind of scientific scrutiny. They were
Speaker 1: basically saying, hey, y'all, would you please check this for us?
Speaker 1: And so that's and that's the process of science. And
Speaker 1: that's really what Jonathan and I talked about in our
Speaker 1: previous episode about BICEP. Let's be responsible scientists, folks, And
Speaker 1: that's exactly what was going on here, which sometimes leads
Speaker 1: to disappointing outcomes, but it's better than UH being wrong
Speaker 1: and just sticking to being wrong, and and even even
Speaker 1: disproving an outcome can be fascinating and in terms of
Speaker 1: research progress moving forward. Right, So, in the case of
Speaker 1: BICEP two, we're talking about using telescopes to try and
Speaker 1: detect UH the presence of gravitational waves through its effects
Speaker 1: on other stuff. But what about just trying to detect
Speaker 1: the presence of gravitational waves themselves, not look at how
Speaker 1: it's affecting something else, but somehow detecting their presence here
Speaker 1: on earth. So let me guess you get two things,
Speaker 1: and you put them a kilometer apart, and you watch
Speaker 1: them real close to see if they vary by the
Speaker 1: width of a thousandth of a proton very close. You
Speaker 1: actually have to get at least three things. Uh, and
Speaker 1: then you have to watch them very close with lasers.
Speaker 1: So this was an idea that was proposed by Ray
Speaker 1: weiss Um. He suggested creating a laser interferometer system to
Speaker 1: detect any sort of distortion in spacetime. And uh, it's
Speaker 1: a really brilliant and elegant solution to a difficult problem. Yeah,
Speaker 1: and and he started working on this along with one
Speaker 1: of the other people who would become a lead on
Speaker 1: the project, Kip Thorne. Kip Thorne, by the way, good name,
Speaker 1: good good job. Kip Thorne's parents. Anyway, So they got
Speaker 1: their start way back in five when the two of
Speaker 1: them happened to share a hotel room at a conference
Speaker 1: and wound up just staying up all night chattering about
Speaker 1: gravitational waves and feel that's not what's going to happen
Speaker 1: to me at south By Southwest, I know anyway, So
Speaker 1: so Thorn wound up pulling in Ronald Drever, who's whose
Speaker 1: original idea I think it was to use lasers for this,
Speaker 1: And the work was originally out of cal Tech because Weiss,
Speaker 1: who was at m I T at the time, couldn't
Speaker 1: convince M I T the black holes were cool enough
Speaker 1: to study sat draw bone. Yeah, he says, by the way,
Speaker 1: that M I T has since gotten better. So LEGO
Speaker 1: is the pair of observatories that was responsible for detecting
Speaker 1: this particular gravitational wave. Have you seen a picture of
Speaker 1: one of the LEGO facilities. Yes, they're really cool. Yeah,
Speaker 1: they look like giant V or an L. Yeah, depends
Speaker 1: on your perspective. I suppose, I guess. I guess so.
Speaker 1: I always thought it L not V shaped, But I
Speaker 1: understand entirely. Um. The so LEGO, the Laser Interferometer Gravitational
Speaker 1: Wave Observatory. Its purpose wasn't to look for gravitational waves
Speaker 1: that were responsible during or were a result oather of
Speaker 1: cosmic inflation. Uh, they're looking for things that happened after
Speaker 1: the Big Bang, things like black holes colliding or these
Speaker 1: neutron stars that are in orbit around one another. That's
Speaker 1: sort of stuff. Those those sort of gravitational waves. The
Speaker 1: presence of gravitational waves that are actively passing through Earth,
Speaker 1: that's what these are looking for. And so they're not telescopes.
Speaker 1: So the discovery that was announced in February is though
Speaker 1: they're both involving gravitational waves, they were sort of fundamentally
Speaker 1: different discoveries between that and the one from Yes. So, uh,
Speaker 1: some interesting stuff about LEGO. It originally went online in
Speaker 1: two thousand two UM and it was the largest project
Speaker 1: to ever be funded by the National Science Foundation at
Speaker 1: that time. They've spent over the past forty years about
Speaker 1: one point one billion dollars in pursuit of this. YEP.
Speaker 1: And like I mentioned before, there are two observing stations.
Speaker 1: One is in Louisiana and the other is in Washington.
Speaker 1: There almost two thousand miles apart. Part I'll talk more
Speaker 1: about exactly how far they are a little bit later,
Speaker 1: but uh uh, the two stations are necessary to confirm
Speaker 1: the presence of gravitational waves. You want that same observation
Speaker 1: to be picked up by both facilities within like ten
Speaker 1: milliseconds of one another for it to be considered a
Speaker 1: potential gravitational wave. Hit right, because otherwise, you know, like
Speaker 1: a really big truck passing by could possibly set off
Speaker 1: one of the monitors. It could be a seismic activity,
Speaker 1: could be anything that would uh jitter the system, if
Speaker 1: you will. And if one of them picks it up
Speaker 1: and the other one doesn't, then that tells you it
Speaker 1: was probably a localized event that gave a false positive
Speaker 1: at one observatory. If both of them pick it up
Speaker 1: again within ten milliseconds of each other and it's clearly
Speaker 1: the same frequency wave, we know it's not a giant
Speaker 1: crayfish attack in the Louisiana location. That's right. It's probably
Speaker 1: we're probably not John Balaya related at that point unless
Speaker 1: they've unless they've colluded, colluding crawfish Washington, right, crawfish collusion.
Speaker 1: I gotta find your stash of though medication, because I
Speaker 1: want whatever you're on, So you don't let's talk about
Speaker 1: so I don't want the cold, that's true. Let's talk
Speaker 1: about the the actual facility. So I think of them
Speaker 1: as being L shaped because there they are the two
Speaker 1: branches or two arms of this facility are at a
Speaker 1: ninety degree angle from one another. And maybe because Lego
Speaker 1: starts with a nail, that also a bit of priming there. Yeah,
Speaker 1: that probably probably helps. You're right, they are at ninety
Speaker 1: degree angle, but it's this giant nine degree angle with
Speaker 1: arms stretching way out into the into the fields. Yeah.
Speaker 1: So there's one that goes under a little road. Did
Speaker 1: you see that one? Because like there's like a they
Speaker 1: built a little tunnel that the arm goes through and
Speaker 1: a road passes over it. And by road, I mean
Speaker 1: like a dirt road. I'm not talking like a highway
Speaker 1: or something. So each branch of the l each arm
Speaker 1: of the is two and a half miles or four
Speaker 1: kilometers long, and it's actually a vacuum tube. They pump
Speaker 1: out all the air uh in the facility in order
Speaker 1: to avoid any kind of absorption, refraction or anything like that,
Speaker 1: any any interference that atmosphere could create while you're firing
Speaker 1: a laser down this tube. And they actually have a
Speaker 1: beam splitter, So they have a single laser that generates
Speaker 1: a laser beam hits a beam splitter. The beam splitter
Speaker 1: splits the beam as the name would indicate into two.
Speaker 1: One goes down one branch, the other one goes down
Speaker 1: the other branch. Remember they're perpendicular to each other. H
Speaker 1: branch has a series of mirrors in it, so the
Speaker 1: lasers bounce off the mirrors and return back to the
Speaker 1: crux of the l and there, because they're both from
Speaker 1: the same laser, they have the same wavelength, they cancel
Speaker 1: one another out. That's where the interferometry comes in. Yes,
Speaker 1: so they interfere with one another. They end up creating uh. Well,
Speaker 1: because they cancel out, there's no more light that's admitted
Speaker 1: through the the that area. And they have a light detector,
Speaker 1: so the light detector would detect if any laser light
Speaker 1: came through. But as long as everything is going perfectly well,
Speaker 1: they cancel each other out. But what if somebody were
Speaker 1: to come along and shorten one of those long arms
Speaker 1: a little bit, Well, then one laser would travel a
Speaker 1: shorter distance than the other laser, and those wavelengths would
Speaker 1: be out of alignment, and then you would get some
Speaker 1: laser light coming out from that, and the light detector
Speaker 1: would pick it up and say, hey, uh, things are hinky.
Speaker 1: So when a gravitational wave moves through. What happens is
Speaker 1: one arm will start to get longer while another arm
Speaker 1: will start to get shorter, and then they alternate because
Speaker 1: they're perpendicular to one another, and that's the way the
Speaker 1: wave propagates across the facility. That's why you have an
Speaker 1: l shape in the first place, because of that ninety
Speaker 1: degree perpendicular alignment means one side is going to always
Speaker 1: be getting shorter while the the one is getting longer
Speaker 1: as a gravitational wave passes through. So that means that
Speaker 1: while the wave is passing through, the laser on one
Speaker 1: side is traveling a shorter distance than the laser on
Speaker 1: the other side, and that ends up creating this mismatch
Speaker 1: of wavelengths, and you get the light leaking through. The
Speaker 1: light detector picks it up and and and then you've
Speaker 1: got data to analyze and you can say, all right,
Speaker 1: we've got a hit. Let's find out if our counterparts
Speaker 1: at the other observatory also picked this up. And if
Speaker 1: they did, then that's a potential gravitational wave. And it's
Speaker 1: really elegant approach to detecting something like this, and it's
Speaker 1: incredibly precise. So I was watching a video where one
Speaker 1: of the engineers was talking about the measurements that are
Speaker 1: made by this, and they said, when we talk about
Speaker 1: differences in distance, we're talking about the distance of ten
Speaker 1: to the minus nineteen power meters small. So again, you
Speaker 1: take a take the number ten, take a decimal place,
Speaker 1: moveing to the left nineteen times put meter behind it.
Speaker 1: That's the distance we're talking about for uh. You know
Speaker 1: that has to be measured when one of these gravitational
Speaker 1: waves passes through, and they're passing through at a fraction
Speaker 1: of a second, so it's incredibly precise, very fast measurement
Speaker 1: that has to take place in order for even one
Speaker 1: of the observatories to say we got a hit. But
Speaker 1: as we mentioned earlier, if only one of them has
Speaker 1: a hit, we know that that's probably a false positive.
Speaker 1: It's probably a localized event in Louisiana or possibly Washington,
Speaker 1: in which case it will make the news. In Louisiana
Speaker 1: it's old hat, but in Washington that would be unusual.
Speaker 1: Uh So, yeah, because they are so far apart by
Speaker 1: specifically it's one thousand between the two or three thousand
Speaker 1: two kilometers, that light does take a little longer to
Speaker 1: it to one versus the other. It all depends on
Speaker 1: what what direction the gravitational wave is coming from. But
Speaker 1: there will be a delay. It's a tiny delay again,
Speaker 1: less than ten milliseconds, but it's enough of a delay
Speaker 1: that if there is that amount of time between the
Speaker 1: two and they're picking up the same frequency wave or
Speaker 1: same frequency in in this interference, then that suggests that
Speaker 1: they found a gravitational wave. And now this kind of
Speaker 1: precision means that they had to go through a little
Speaker 1: bit of a growth period before they could really get
Speaker 1: these things working. Yeah, so here's here's the bad news
Speaker 1: they had to give. The facility came online in two
Speaker 1: thousand two, by it was clear that the instrumentation they
Speaker 1: were using was not going to be precise enough to
Speaker 1: pick up gravitational waves. It didn't matter how long they
Speaker 1: left it on, it was just not precise enough. And
Speaker 1: they had to go back to the drawing board and say,
Speaker 1: we're gonna need to upgrade these facilities in order for
Speaker 1: them to be capable of detecting this. If in fact,
Speaker 1: gravitational waves are a thing, then we're going and we
Speaker 1: know that they are, but in order for us to
Speaker 1: detect them, we're gonna have to get more precise. So
Speaker 1: in twousen LIGO goes offline and there was an international
Speaker 1: collaboration that took five years of work to overhaul and
Speaker 1: upgrade LIGO until they got advanced LEGO or a. Yeah.
Speaker 1: The observatories came back online in September two thou fifteen,
Speaker 1: and literally days after turning on, they detected a gravitational wave.
Speaker 1: So think about this for a second. The gravitational wave
Speaker 1: they detected was from a pair of black holes colliding.
Speaker 1: That pair of black holes collided one point three billion
Speaker 1: years ago, and that means that the black holes were
Speaker 1: by definition one point three billion light years away from Earth,
Speaker 1: because again, gravitational waves travel at speed of light. So
Speaker 1: one point three billion years ago, one point three billion
Speaker 1: light years away, two black holes collided, and the facility
Speaker 1: came online just days earlier at you know, on Earth
Speaker 1: one point three billion years later. To catch it. That's
Speaker 1: like the biggest dartboard you can imagine with the tiniest
Speaker 1: bull's eye, and you are miles away and you just
Speaker 1: happened to throw it perfectly well, so that catches the
Speaker 1: air and flies over and hits that bull's eye. Now granted,
Speaker 1: that is pretty amazing, but it's also it's a big universe.
Speaker 1: Is a big universe, and people have said that things
Speaker 1: like the black holes colliding events of that nature happened
Speaker 1: in the universe on the order of about every fifteen minutes,
Speaker 1: but it all depends on when and where they happened,
Speaker 1: right like if it happened a billion years ago, but
Speaker 1: it's four billion light years away, it will be three
Speaker 1: billion more years before those gravitational waves make it to Earth.
Speaker 1: So because the universe is big, yes, these things happen
Speaker 1: all the time, but they don't hit Earth all the time. Yeah,
Speaker 1: it was still pretty cool. Yeah, it's really really cool,
Speaker 1: so cool that I remember on the day it was
Speaker 1: announced one of the people working at Lego said, Yeah,
Speaker 1: at first we thought that they might have been testing
Speaker 1: the system again, and then we checked and no one
Speaker 1: was testing the system and we were like, whoa, it works.
Speaker 1: And so that was just one of those like great
Speaker 1: fortuitous moments um and yeah, it was very exciting. Of course,
Speaker 1: they wanted to take time to confirm it, to validate
Speaker 1: the information, which is why we did not hear about
Speaker 1: it till February eleven, twenty sixteen, so it was some
Speaker 1: time later before we got a chance to find out
Speaker 1: what the big discovery was. You know. One of the
Speaker 1: cool things to me about this, uh, this observation, they
Speaker 1: called it a chirp. Yeah, the thing that they detected
Speaker 1: of the gravitational waves. And because it's a wave with
Speaker 1: a certain number of number of oscillations per second represented
Speaker 1: as hurts, you can actually represent this chirp as sound,
Speaker 1: which people have done there. I watched one YouTube video
Speaker 1: that was a compilation of different scientists and people who
Speaker 1: were involved with the project doing doing little chirps, doing
Speaker 1: their little gravitational wave of chirps with their mouths and
Speaker 1: devices and stuff. I'm so glad I didn't make one
Speaker 1: of those videos, would be so tempted just to do
Speaker 1: the whole stupid Rick Roll thing. So the Louisiana Observatory
Speaker 1: detected that gravitational wave first, and seven milliseconds later the
Speaker 1: Washington Observatory detected it. So that's what when they were
Speaker 1: able to say, yes, this does appear to be a
Speaker 1: gravitational wave. And they used triangulation to determine where did
Speaker 1: this come from, and they determined that it was coming
Speaker 1: from the Southern hemisphere skies um and that's what led
Speaker 1: them to the conclusion of hey, you know, we this
Speaker 1: this is working. We understand where this is coming from
Speaker 1: and even what's causing it, which was really cool, But
Speaker 1: that wasn't all they were able to tell about it
Speaker 1: from the data collected. In fact, they were able to
Speaker 1: look at the data they had and say what they
Speaker 1: think happened to cause these gravitational waves? Yeah, yeah, Like so,
Speaker 1: let's it's hard to explain how huge a moment this is.
Speaker 1: It's it's very difficult to kind of put that into words.
Speaker 1: But keep in mind that black holes, while we understand
Speaker 1: they are a thing, it's not something that we directly observe, right,
Speaker 1: But you can't see a black hole, because that's rather
Speaker 1: the point. Yeah, they really, you really can't. You can
Speaker 1: see the effects off of them and nothing escapes from them.
Speaker 1: So yeah, you can. You can see how gas clouds
Speaker 1: behave in vicinity of you know, like in the Kessel run,
Speaker 1: you see gravitational lensing. Yes, you can see gravitational lensing.
Speaker 1: But you know, this is about as strong evidence for
Speaker 1: the existence of black holes as you can get without
Speaker 1: sending Matthew McConaughey through one um, and certainly the strongest
Speaker 1: evidence for binary black holes where you have to colliding
Speaker 1: with one another, and the data picked up matched the
Speaker 1: calculations that that people had made based upon the knowledge
Speaker 1: of general relativity in physics about what would happen with
Speaker 1: these two black holes so well that it was phenomenal.
Speaker 1: So reality and math were actually agreeing with one another,
Speaker 1: which is fantastic. They determined the black holes in question
Speaker 1: were pretty pretty big, not like super massive black holes.
Speaker 1: We're not talking about the kind that would be at
Speaker 1: the center of a galaxy or anything. But one had
Speaker 1: twenty nine times the mass of our Sun and the
Speaker 1: other thirty six times the Sun's mass, and right before
Speaker 1: they collided, they were circling each other two and fifty
Speaker 1: times a second UM. During the actual collision, which took
Speaker 1: place over about a fifth of a second, they blogged
Speaker 1: together and then coalesced into like a smooth sphere in
Speaker 1: a process that's called ring down and ring down and
Speaker 1: it's and it's this process in which three solar masses
Speaker 1: worth of energy was vaporized that that caused the gravitational
Speaker 1: waves that we observed um. The resulting black hole, by
Speaker 1: the way, is therefore only sixty two times the mass
Speaker 1: of the Sun, being that three masses just went. Yeah,
Speaker 1: and when you think about energy equals mass times the
Speaker 1: speed of light squared, and you think three solar masses vaporized,
Speaker 1: that's that's an unimaginably huge amount of energy, right, Like
Speaker 1: it's so enormous that I can't even begin to think
Speaker 1: about it, so I won't. Yeah, yeah that but but yeah,
Speaker 1: if you're wondering how something that was that far away
Speaker 1: propagated all the way to Earth, that's why. So again
Speaker 1: remarkable that this facility even picked up the signal in
Speaker 1: the first place, considering that, you know, it all has
Speaker 1: to be timed out where this thing that happened one
Speaker 1: point three billion years ago, one point three billion light
Speaker 1: years away. Uh, just the observatory coming online when it did,
Speaker 1: like all of that is pretty phenomenal stuff. Yeah, and
Speaker 1: they almost didn't do the engineering run during which the
Speaker 1: signal was found. Uh, just three days prior, the Livingstone
Speaker 1: antenna was getting some radio interference and White actually recommended
Speaker 1: that they put off the run. But his colleagues they're
Speaker 1: were like, Nah, let's let's go ahead. We think it's ready,
Speaker 1: so don't worry about it. The nice thing is that
Speaker 1: we know eventually this would have worked anyway, but it
Speaker 1: was still just just one of those cool stories about
Speaker 1: how much came into alignment to allow it to happen
Speaker 1: so early. When it came back online, it's a great
Speaker 1: story for science. Well. One of the things that I
Speaker 1: have definitely heard reported from some of the people involved
Speaker 1: in the project is that the signal was much stronger
Speaker 1: than they expected it to be. Like they they were
Speaker 1: able to see the signal clearly in the data with
Speaker 1: the naked eye just looking at the data. They're like, oh,
Speaker 1: there it is. When what they thought they we're gonna
Speaker 1: have to do was like run a you know, computational
Speaker 1: analysis across all the data and compare it to uh
Speaker 1: to random noise generated as a sort of cross reference,
Speaker 1: and see if it maybe was a gravitational wave. But no,
Speaker 1: it was just obvious, which is amazing. And so this
Speaker 1: is kind of wrapping up our initial discussion about gravitational waves.
Speaker 1: In our next episode, we're gonna talk a little bit
Speaker 1: more about the specifics of what Lego found. I'm gonna
Speaker 1: talk a little bit about some angular momentum. In that episode,
Speaker 1: we'll also talk about what does this mean and the
Speaker 1: rise of a new type of astronomy, gravitational astronomy, which
Speaker 1: is literally in its infancy right now. Uh and what
Speaker 1: could this possibly mean for the future? That will be
Speaker 1: in our next episode. Guys, if you have suggestions for
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