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Speaker 1: Hey, jorgey, do you think there's anything good about getting older?

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Speaker 1: Why are you asking me? I'm only twenty three. How

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Speaker 1: long you've been twenty three for a while? Yeah? All right,

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Speaker 1: But do you think like there's any advantage to getting

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Speaker 1: old and slowing down? I guess fewer speeding tickets. Maybe

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Speaker 1: like new kinds of joint pain to feel so new experiences. Yeah,

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Speaker 1: the early bird specials at restaurants. Sometimes I wonder if

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Speaker 1: it's good to forget some of those painful memories of youth.

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Speaker 1: So there are advantages. Maybe physics should try slowing down.

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Speaker 1: You want me to tell these photons to take it easy,

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Speaker 1: you know. I know they're billion years old and they've

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Speaker 1: been going at the speed of light for a long time,

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Speaker 1: but maybe it's time for them to slow down. They

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Speaker 1: can get the early Photon special. Hi'm Jorge Mae, cartoonist

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Speaker 1: and the creator of PhD comments. Hi. I'm Daniel. I'm

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Speaker 1: a particle physicist and I hope to be aging gracefully

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Speaker 1: and welcome to our podcast. Daniel and Jorge age and

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Speaker 1: explain the universe. At the same time, Daniel and Jorge

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Speaker 1: explained the aging of the universe, which is mostly my

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Speaker 1: knees at this point, which is technically happening right now,

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Speaker 1: right now, as you're listening to us. We are getting older, yes,

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Speaker 1: and the universe is getting older. You will finish this

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Speaker 1: podcast in a different, older universe than the when you

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Speaker 1: started it in, right, A little bit bigger, a little

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Speaker 1: bit older and wiser, a little bit cooler, a little

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Speaker 1: bit darker. The universe is getting older and colder and slower.

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Speaker 1: Um though dark energy, of course is accelerating. But those things,

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Speaker 1: when they get older, so to slow down, just like us,

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Speaker 1: it gets a little bit more boring. No, we are

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Speaker 1: getting funnier as we get older. Jorge, Oh right, right, No,

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Speaker 1: I mean like entropy, Like entropy is increasing in the universe,

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Speaker 1: and so is the entropy of our knees and jokes. Well,

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Speaker 1: maybe as we get older we don't get funnier, but

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Speaker 1: we think we're funnier, So I laugh more at your jokes,

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Speaker 1: even as they decay in quality. It's all about perspective.

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Speaker 1: It's all about perspective. Just like in relativity, there is

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Speaker 1: no universal time or distance in comedy, right, there is

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Speaker 1: no universal humor. There's no universal law for jokes. Is

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Speaker 1: there no theory of special comedy. Um, well, there are

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Speaker 1: a lot of jokes about relatives, but everybody jokes about

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Speaker 1: their family, right, Yeah. Yeah, this idea that everything is

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Speaker 1: slowing down is kind of inevitable. But there are some

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Speaker 1: things in the universe and maybe we'll never slow down.

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Speaker 1: That's right. Even though photons travel through billions of light

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Speaker 1: years of space, when they get here, they're still moving

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Speaker 1: at the speed of light. You you fired that photon

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Speaker 1: from your flashlight at Alpha Centauri, It's gonna get there,

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Speaker 1: and it's going to be going the same speed when

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Speaker 1: it does. Yeah, I kind of thought about it. I

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Speaker 1: guess photons are going at the same speed wherever they go,

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Speaker 1: no matter how long they've been going. Yeah, photons don't

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Speaker 1: get tired, right. You push a photon and it goes,

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Speaker 1: and it just goes and goes and goes and goes

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Speaker 1: and goes, and it doesn't like run out of energy,

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Speaker 1: you know, unless it gets absorbed by something or bounces

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Speaker 1: off something. It will just keep going forever. It's sort

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Speaker 1: of amazing at the maximum speed of the universe, not

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Speaker 1: just at any speed. At the maximum speed of the universe. Yeah,

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Speaker 1: and photons. People have been asking me on Twitter whether

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Speaker 1: photons experienced time, Like do photons even get old? You know,

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Speaker 1: because photon has taken a billion years to get here

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Speaker 1: from somewhere else, And they wonder do photons experienced time?

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Speaker 1: And it's a tricky question because you have to imagine,

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Speaker 1: like a photon having a clock. What is that clock

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Speaker 1: made out of? If it has mass than the photons can,

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Speaker 1: how does it look at the clock? Photons to look

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Speaker 1: at the clock. What is it like to be a photon? Man?

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Speaker 1: It seems like maybe more of a philosophical question than

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Speaker 1: a physics question. Yeah, I don't think photons even have

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Speaker 1: knees to feel their joint. Paine, I'm not asking whether

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Speaker 1: we have anything in common with photons. There are weird

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Speaker 1: quantum mechanical little particles. But where we ended up with

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Speaker 1: that question was that photons are moving at the speed

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Speaker 1: of light, and so they see most of the universe contracted.

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Speaker 1: So a photon leaves here and it feels like it

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Speaker 1: hasn't gone very far because the universe has been sort

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Speaker 1: of shortened. To them, the universe is just it's it's

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Speaker 1: it's basically tiny, right, It's the size of a point. Maybe, Yeah,

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Speaker 1: that's right, And it's bizarre to imagine what it might

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Speaker 1: be like to travel as a photon. But again, I

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Speaker 1: don't think we want to get into the question of

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Speaker 1: what is it like to be a photon? But it

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Speaker 1: is sort of a good life example to not slow down,

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Speaker 1: you know, take some inspiration. Photons are my new heroes.

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Speaker 1: But other folks have been writing in and asking about

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Speaker 1: whether photons always do at the speed of light? Can

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Speaker 1: they not go at the speed of light? Can they

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Speaker 1: throttle down? Yeah? When photons get old, is there any

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Speaker 1: way they can sort of chill out a little bit

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Speaker 1: and relax? So to the on the podcast, we'll be

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Speaker 1: askering this question dead several, he says. Several readers wrote

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Speaker 1: in about there are a bunch of people who've been

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Speaker 1: reading articles online about physicists managing to slow down light,

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Speaker 1: and they thought, what we better get Daniel and Jorge

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Speaker 1: to explain that to us, So to be on the program,

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Speaker 1: we'll be asking the question can light be slowed down?

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Speaker 1: It's fascinating because people think that, of course, photons travel

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Speaker 1: at the speed of light, right, that's why we call

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Speaker 1: it the speed of light, And we make a big

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Speaker 1: deal about how that's constant. How if you shoot a

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Speaker 1: photon out you measure traveling at the speed of light,

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Speaker 1: somebody else measures it traveling at the speed of light.

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Speaker 1: This sort of this like fundamental constancy, This like stubbornness

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Speaker 1: of photons to always go with the same speed. Other

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Speaker 1: things can vary their speed, right, Electrons orcs sure, pretty

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Speaker 1: much all the other trinos. Right, they can go slow,

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Speaker 1: they can sit in the palm of your hand, or

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Speaker 1: they can go at nearly the speed of light. Yeah,

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Speaker 1: anything that's massive that has any mass to it, electrons,

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Speaker 1: even newtrinos, anything like that has a rest mass, Like

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Speaker 1: you can catch up to it and have no relative velocity.

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Speaker 1: You can exist next to it, hold it, throw it around, etcetera.

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Speaker 1: But things that have no mass, what would happen if

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Speaker 1: you caught up to them? Right, If there's a photon

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Speaker 1: and you caught up to it, a photon is just motion, right,

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Speaker 1: There's nothing to it other than it's motion. So if

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Speaker 1: you catch up to it and there's no motion, there's

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Speaker 1: no velocity relative to the photon, it's not there anymore.

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Speaker 1: So that's why you can never catch up to a photon.

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Speaker 1: It just doesn't make sense. It's like what happens if

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Speaker 1: you catch a wave. It's no longer a wave. Yeah,

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Speaker 1: that's right. If you're surfing right and you look down,

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Speaker 1: then it's not really a wave anymore. It's just sort

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Speaker 1: of like a stationary shape of the water, and so

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Speaker 1: there's no relative motion there. Yeah, So don't surf on

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Speaker 1: photons people. Not a good idea, especially as you get older. Yeah,

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Speaker 1: and so this is an interesting question and so that

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Speaker 1: we're going to tackle it today. We're gonna talk about

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Speaker 1: whether or not you can slow light down and whether

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Speaker 1: it seems that people some people have. Yeah, there's been

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Speaker 1: some pretty exciting experiments with click baby headlines about slowing

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Speaker 1: down light and stopping light, and so we're gonna dig

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Speaker 1: into that today. And see doesn't make any sense. What

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Speaker 1: are they actually doing and is it cool or what?

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Speaker 1: Oh stopping You're gonna slow it down to the point

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Speaker 1: of maybe stopping light. Yeah, yeah, wow, these faces are

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Speaker 1: trying to break the rules of the universe. Well, as usual,

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Speaker 1: I was curious, do people think it's possible to slow

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Speaker 1: down light or is that just sound like crazy talk?

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Speaker 1: So I walked around campus at you see Irvine. Yeah,

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Speaker 1: so before you listen to these answers, think about it

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Speaker 1: for a second, do you think that light can be

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Speaker 1: slowed down? Here's what people have to say. I don't

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Speaker 1: think so. I don't know. I would say no, theoretically right, yes, yes,

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Speaker 1: how would you do it? I'm no clue. I don't

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Speaker 1: know that that photons within the sun, they it takes

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Speaker 1: very long time until they actually reach the surface of

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Speaker 1: the sun and are released into space. I don't know.

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Speaker 1: I mean it's not actually it's it's learned on the photons.

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Speaker 1: I mean, there's there's relativity obviously, so I closed down time.

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Speaker 1: But that's that's time. But that's light is supposed to

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Speaker 1: be the constant nation. Because it is a constant. I

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Speaker 1: think if you put light through different media, that should

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Speaker 1: be slow. But I don't think that it is like

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Speaker 1: I would expect that if you put light through water,

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Speaker 1: I would expect there would be some sort of effect.

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Speaker 1: But but we have a constant for light, So how

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Speaker 1: can it be how can it change through different media?

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Speaker 1: And if we have a constant for it, that's like,

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Speaker 1: but we that's constants for an error? Yes, isn't it okay?

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Speaker 1: So maybe it is okay? So I think there might

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Speaker 1: be slight changes possibly, but I think it's inherently supposed

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Speaker 1: to be constant. No, because it isn't like a constant number.

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Speaker 1: I think somehow through velocity or something of that, changing

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Speaker 1: velocity at a very high rate might be able to

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Speaker 1: I'm not too sure. Maybe like a black hole type

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Speaker 1: gravity type of situation. Yeah, No, cool, some pretty cool

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Speaker 1: answers here. A lot of a lot of yeses and

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Speaker 1: a lot of maybes. I don't know how how did

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Speaker 1: people react to the question itself, because it's not a

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Speaker 1: question that I had heard much about before you send

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Speaker 1: me the email this morning. Uh, you know it's you

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Speaker 1: don't think about the slowing down light down much. Well.

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Speaker 1: I think that feeling is backed up by these people's experience,

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Speaker 1: because when I asked them, do you think it's possible

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Speaker 1: to slow down light? I got a lot of quizzical

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Speaker 1: looks and a lot of long pauses as people thought

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Speaker 1: about it, And you can hear people reaching for answers.

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Speaker 1: They're like, I don't know, is a black hole involved? Maybe?

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Speaker 1: Or you kind of have to stop and parse the

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Speaker 1: words a little bit, like slow down light, slow down

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Speaker 1: something that is not quite there, yep, And parsing the

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Speaker 1: words is going to be a solution to today's question

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Speaker 1: because the answer is sort of technical and legalistic. It's

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Speaker 1: sort of one of these pole loopholes in the laws

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Speaker 1: of physics, like have you really slowed it down? Some

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Speaker 1: people would say they have. Some people would, you know,

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Speaker 1: quibble with that. All right, So we have to put

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Speaker 1: on our physics lawyer heads today. Whenever you're reading the

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Speaker 1: laws of physics, you've got to be very careful, you know,

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Speaker 1: to understand exactly what they mean and what they don't mean.

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Speaker 1: Are we sort of the shark type of physics lawyer?

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Speaker 1: Are we been nice type of physics lawyers today? Are

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Speaker 1: we out to get the universe? Are we up to?

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Speaker 1: Are we out for justice? Danny? We are not the

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Speaker 1: physics police, right, we are on this. We're on the

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Speaker 1: defense side here. We are trying to make sure physicists

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Speaker 1: can do whatever they like. We're trying to allow physics

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Speaker 1: to do weird stuff with the universe because in the end,

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Speaker 1: that's how we learn what the rules really are. We

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Speaker 1: find the cracks and we exploit them, try to figure

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Speaker 1: out what's actually possible given the rules that we know.

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Speaker 1: It seems like people had a sense that, you know,

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Speaker 1: the universe is interesting enough that maybe there are situations

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Speaker 1: in which you can slow light down. Like that didn't

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Speaker 1: seem impossible to a lot of people. Yeah, that's an

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Speaker 1: optimistic way to look at it. Like, no matter how

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Speaker 1: constant you think that law is, there must be some way,

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Speaker 1: someplace in the universe where we could break and we

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Speaker 1: could find something crazy happening. I like thinking that people

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Speaker 1: are open to the fact that the universe is filled

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Speaker 1: with crazy bunker stuff. Okay, so let's break it down

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Speaker 1: for folks here, Daniel, and let's talk about light and

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Speaker 1: how facet travels and what we know about light. And

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Speaker 1: it's the first thing to understand, which I think most

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Speaker 1: people already do, is that light does always travel at

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Speaker 1: the same speed in a vacuum. And remember what light

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Speaker 1: is like. You can think about light as a photon

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Speaker 1: is a little particle, and it is quantized. But if

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Speaker 1: fundamentally think about light is a sort of a ripple.

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Speaker 1: Space is filled with quantum fields. Even empty space has

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Speaker 1: the possibility to have these particles in it because it

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Speaker 1: contains within it these quantum fields, like the electromagnetic field

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Speaker 1: that can ripple. So I think of space is sort

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Speaker 1: of like having these different possible sort of sheets rubber

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Speaker 1: sheets in it, and mostly they're just sort of spread.

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Speaker 1: It's smooth, but occasionally you can get a ripple in one,

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Speaker 1: and that ripple is like a particle. I see. So

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Speaker 1: I think the main idea is that light is a

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Speaker 1: photon is not a thing. It's not like a little

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Speaker 1: spherical thing. It's more like like a little divid in

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Speaker 1: the kind of the fabric of the universe. Yeah, it's

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Speaker 1: got no stuff to it, if that's what you mean

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Speaker 1: by it's not a thing. It's a it's a transient property, right,

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Speaker 1: It's that's why it's always moving. It's a it's a ripple.

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Speaker 1: It's like a change in information. It's saying, oh, the

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Speaker 1: electromag than the field was this, so now it's that,

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Speaker 1: And it's that change that is the photon. That's why

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Speaker 1: we say that photons carry information because they're like they're

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Speaker 1: carrying information about how these fields are changing, the fields

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Speaker 1: going up, and then it's going down, the fields going

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Speaker 1: up and then it's going down. That is, the photon

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Speaker 1: doesn't actually move like a like a thing. We can

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Speaker 1: think of a coffee mug moving from one side of

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Speaker 1: my desk the other side of the desk, but a particle.

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Speaker 1: A quantum particle is more like um like an effect.

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Speaker 1: This part tells the other part, and then that part

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Speaker 1: there's the next part, and then it just propagates. Yeah,

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Speaker 1: Like if you and I hold it ump rope between

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Speaker 1: us and we spind the jump rope, no part of

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Speaker 1: the jump rope is moving sideways, like closer to me

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Speaker 1: or to you. That's just moving up and down. But

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Speaker 1: we can send pulses down that jump rope. Right, if

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Speaker 1: I wiggled it really fast, I can send what looks

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Speaker 1: like a pulse, But no part of the rope is

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Speaker 1: moving sideways. But the pulse is moving sideways that the

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Speaker 1: wiggle is moving, but the rope isn't moving. Yeah, and

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Speaker 1: even the coffee cup, and the coffee cup is made

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Speaker 1: of particles, and those particles are ripples in their fields,

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Speaker 1: electron fields, cork fields, whatever, So when the coffee cup moves,

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Speaker 1: it's actually the same thing. It's just like a bunch

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Speaker 1: of little tiny ripples are moving sideways through the universe.

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Speaker 1: That's such a hard warming image, you know, the two

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Speaker 1: of us jumping rope together. I feel like I feel

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Speaker 1: like I imagine we're in some you know, like city

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Speaker 1: block and we're jumping rope and there's children singing, and

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Speaker 1: we're having the time of our lives and there's leaves

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Speaker 1: blowing everywhere. And afterwards we're sipping hot cocoa and sort

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Speaker 1: of a warm, fuzzy camera glow, and we're being interviewed

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Speaker 1: by Oprah Like, that's what you're imagining. Yeah, you're sure

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Speaker 1: that's going to happen for us. I feel so much

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Speaker 1: lighter there. Well, that's good because we're talking about light.

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Speaker 1: And so that's what photons are, right, their ripples in

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Speaker 1: this electromagnetic field. And the reason that they move at

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Speaker 1: the speed of light in a vacuum is that then

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Speaker 1: it's just pure electromagnetic field, and they move at the

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Speaker 1: maximum speed of information, which is the speed of light

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Speaker 1: in a vacuum. So things that are not photons, like

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Speaker 1: electrons and corks, they're also you're saying, they're also a

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Speaker 1: little perturbations in fields as well. They're just like photons

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Speaker 1: in that they're They also don't move in the universe.

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Speaker 1: They just propagate. Yes, they propagate through the electron field

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Speaker 1: or the cork field, for example. And so an electron

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Speaker 1: moves through the universe and it moves at whatever speed

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Speaker 1: it's moving, and it's a wiggle in that field. And

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Speaker 1: you might ask, well, how come the electron field wiggles

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Speaker 1: and it doesn't wiggle the same speed as the photon field? Right, Yeah,

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Speaker 1: how come an electron wiggle can variate its speed? Boom?

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Speaker 1: We have a gray answer for that. It's the Higgs

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Speaker 1: boson because the electron field is not free, it's tied

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Speaker 1: to this other field, the Higgs field, that changes how

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Speaker 1: it wiggles. And that's what it means for a particle

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Speaker 1: to have mass, is that it interacts with this Higgs

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Speaker 1: Boson field that changes how ripples move through it, and

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Speaker 1: it changes it exactly the way you would expect if

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Speaker 1: something had mass. It gives those fields inertia. So mass

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Speaker 1: is more like whether or not it interacts with the

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Speaker 1: Higgs field, which would slow it down as it moves

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Speaker 1: through the universe. Yeah, it doesn't actually slow it down.

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Speaker 1: It gives it inertia. It makes it harder to speed

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Speaker 1: up and harder to slow down. Right, It's a tiny

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Speaker 1: bit more complicated than just slowing down. The Higgs field

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Speaker 1: is not like molasses that tries to get everything to

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Speaker 1: go to zero speed. It just keeps things at the

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Speaker 1: same speed. It makes it hard to change velocity. Oh,

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Speaker 1: I see, but light light doesn't interact with the Higgs field,

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Speaker 1: so it just always kind of ignores the Higgs field

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Speaker 1: and just goes as fast as it can. Yeah, and

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Speaker 1: it's actually fascinating. We should do an entire podcast on

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Speaker 1: this electroweak symmetry. Like the photon doesn't interact with the

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Speaker 1: Higgs field at all, but the W and the Z particles,

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Speaker 1: which are very similar to the photon, do interact with

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Speaker 1: the Higgs field and become really heavy, and that's why

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Speaker 1: the weak field is weak. All right. So there's a

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Speaker 1: lot of details in there, but the main idea is

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Speaker 1: that a light is a wiggle and it always travels

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Speaker 1: at this speed of light in a vacuum, in a

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Speaker 1: vacuum precisely. All right, Let's get into this idea of

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Speaker 1: maybe whether or not you can slow this wiggle of

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Speaker 1: light and how you would do that and why you

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Speaker 1: would want to do that. First, let's take a quick

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Speaker 1: break up. Okay, Daniel, So you're telling me that light

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Speaker 1: always moves at the speed of light. Yeah, deep inside

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Speaker 1: here from did you know horge also always travels at

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Speaker 1: the speed of Horge that's gonna to a hundred dollars

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Speaker 1: physics consulting feed speed of X moves at the speed

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Speaker 1: of X. Yeah, but I guess on like light, my

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Speaker 1: the horhead, the speed of horhead slows down, is going

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Speaker 1: to be slowing down, is slowing down, is going to

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Speaker 1: slow down as I get older. But the speed of

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Speaker 1: light doesn't seem to change at all. Yeah, And so

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Speaker 1: we should separate because again, physics has been terrible about naming,

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Speaker 1: because when we talk about the speed of light, often

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Speaker 1: what we mean is maximum speed of information in the universe.

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Speaker 1: Light in a vacuum happens to travel at that speed,

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Speaker 1: and because of historical reasons, we called that speed the

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Speaker 1: speed of light. Oh man, you mean physicists name things wrong, Yes, badly,

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Speaker 1: and they could have really named it that really the

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Speaker 1: speed of light, We should just call it the maximum

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Speaker 1: speed of the universe. Yes, the maximum speed the universe

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Speaker 1: is separate from the speed of light, because it turns

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Speaker 1: out there are lots of different ways to make light

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Speaker 1: move slower than the maximum speed of the universe. So

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Speaker 1: it's really like a definitions thing, like we just have

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Speaker 1: to wrap our shift that little lever in our heads

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Speaker 1: and not call it the speed of light anymore. That's right,

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Speaker 1: Welcome to physics legalities. Right, But officer, I was not

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Speaker 1: traveling faster than the maximum speed of the universe. It

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Speaker 1: technically didn't break the speed limit of this highway. It's

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Speaker 1: just that the speed limit of this highway is not

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Speaker 1: the maximum speed of the universe. I'm sure that that's

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Speaker 1: going to get you off that ticket yet. Well, well, well,

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Speaker 1: and in the ideal scenario, the officer is a fan

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Speaker 1: of our show and just pulled you over to get

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Speaker 1: your autograph. That's right on this speeding ticket. And we

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Speaker 1: talked in the podcast UM recently actually about drink off

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Speaker 1: radiation and what happens when life gets slowed down as

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Speaker 1: it passes through a material and other particles zip passed it.

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Speaker 1: That's a whole fun, complicated topic. Okay, so we can't

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Speaker 1: decrease the maximum speed of the universe, but you can

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Speaker 1: make the light go slower than it would in a vacuum,

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Speaker 1: or slower than the maximum pet Yeah, you can make

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Speaker 1: photons move slower than the maximum speed. And the way

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Speaker 1: you do it is you get them to go through

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Speaker 1: some material. Because we said that photons move at the

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Speaker 1: maximum speed when it's just a pure electromagnetic field and

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Speaker 1: a ripple. But if you put other stuff in there,

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Speaker 1: like an electron field. Electrons interact with electromagnetic fields, right,

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Speaker 1: They have charge and so they will interact with it.

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Speaker 1: And like a photon can get absorbed by an electron,

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Speaker 1: you have an electron that's zipping around a nucleus, it

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Speaker 1: can absorb that photon, hang onto it for a minute,

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Speaker 1: and then re emit it. So that effectively slows down

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Speaker 1: the photon because it gets from A to B in

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Speaker 1: more time than it would if it hadn't been absorbed. Right,

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Speaker 1: Like if you want to slow down Hussain Bolt, you

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Speaker 1: would have him run through a crowd of people, not

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Speaker 1: on an empty track, That's right. Or Jorge driving to

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Speaker 1: work takes less time than Jorge driving to work past

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Speaker 1: the banana shop because he stops, he takes some bananas.

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Speaker 1: It takes some ten minutes. Everybody wonders why he's late.

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Speaker 1: You know, I'm not sure anyone wonders anymore why I'm late.

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Speaker 1: Daniel put, I'm just glad that you didn't say that

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Speaker 1: I drove through a crowd of people. That's where where

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Speaker 1: you were going. I'm like, oh, it just just got

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Speaker 1: really dark though this is a family friendly podcast, that's right, right, Yeah,

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Speaker 1: I guess what you mean is if you want to

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Speaker 1: slow light down, you sort of keep it busy. Yeah,

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Speaker 1: you interact with it. You you know, Jorge passing through

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Speaker 1: a crowd of his admirers is going to have to

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Speaker 1: stop and sign autographs more often, and so he's not

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Speaker 1: going to get to the other side of the room

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Speaker 1: as quickly. Yeah, although these days people don't ask for

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Speaker 1: autograph date just asked for selfies mostly. Well, that saves

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Speaker 1: your risk, I hope. And to listeners that might feel

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Speaker 1: like a technicality, like is the light really traveling less

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Speaker 1: than the speed of light? Because it's not really. It's

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Speaker 1: between interactions. It's still moving at the maximum speed limit.

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Speaker 1: It's just that those interactions take some time. And and

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Speaker 1: that's that's totally fair. And again it just depends on

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Speaker 1: how you define it. Like you shoot a beam of

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Speaker 1: light into glass, when does it come out the other

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Speaker 1: side more time? It would take more time than if

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Speaker 1: you shot a beam into vacuum. So that's what we

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Speaker 1: mean when we say have we slowed down the light?

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Speaker 1: I guess you know the image I have in my

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Speaker 1: head is sort of like a pinball machine or like

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Speaker 1: a pachinko machine. Have you seen those Japanese pinball games

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Speaker 1: where the little ball wants to go in a straight line,

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Speaker 1: but it keeps bumping into things in between? Now, is

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Speaker 1: that sort of what's happening where it's like bumping between

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Speaker 1: things or is it really more like the interaction slow

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Speaker 1: the light down? Both. It can't move in a straight

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Speaker 1: line through material. It's getting deflected. But all deflections are

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Speaker 1: also interactions, and sort of a philosophical question here, right,

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Speaker 1: If the photon is deflected, is it the same photon

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Speaker 1: as the one that came in? It seems like a

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Speaker 1: clear question if it gets like fully absorbed and then

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Speaker 1: re emitted. But if it gets deflected, it's still there's

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Speaker 1: an interaction there, and so it's a different quantum state.

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Speaker 1: Oh it actually does get deflected. Well, yeah, Photons moving

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Speaker 1: through material don't move in a straight line. They get

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Speaker 1: bounced around like a pachinko machine between particles. Sometimes they

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Speaker 1: get absorbed and re emitted, sometimes just deflected um. And

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Speaker 1: you know, some could argue that those are very different

426
00:22:12,280 --> 00:22:14,600
Speaker 1: kind of experiences for the photons. Some could argue they're

427
00:22:14,640 --> 00:22:17,560
Speaker 1: all interactions so it's all the same deal. But yeah,

428
00:22:17,640 --> 00:22:20,520
Speaker 1: they interact and they get deflected, so it takes longer

429
00:22:20,560 --> 00:22:22,280
Speaker 1: to get from one side of the material to the other.

430
00:22:22,520 --> 00:22:24,879
Speaker 1: I see. So is what slows the light down the

431
00:22:25,320 --> 00:22:28,879
Speaker 1: detours that's taking or is there actually kind of time

432
00:22:28,960 --> 00:22:33,320
Speaker 1: wasted in getting absorbed and re emitted by something in

433
00:22:33,320 --> 00:22:36,040
Speaker 1: the material. It's both both. Those are two different kinds

434
00:22:36,040 --> 00:22:38,800
Speaker 1: of interactions, but they both contribute to making light go

435
00:22:38,960 --> 00:22:42,240
Speaker 1: most more slowly through the material. And it's sort of

436
00:22:42,280 --> 00:22:45,440
Speaker 1: similar to like, you know, making waves move more slowly

437
00:22:45,520 --> 00:22:48,479
Speaker 1: through some material, Like if you if you make waves

438
00:22:48,480 --> 00:22:50,720
Speaker 1: in water, it's different than if you make waves in

439
00:22:50,800 --> 00:22:53,800
Speaker 1: honey or in molasses. Right, there's just a different sort

440
00:22:53,800 --> 00:22:56,879
Speaker 1: of speed of information traveling through that material. And again

441
00:22:56,880 --> 00:22:59,600
Speaker 1: it's because the interactions, like honey holds itself together with

442
00:22:59,640 --> 00:23:02,040
Speaker 1: more wrongly than water does. It's really the same deal.

443
00:23:02,280 --> 00:23:03,760
Speaker 1: So then it sort of depends on what you mean

444
00:23:03,760 --> 00:23:08,080
Speaker 1: by light, like it's light natural photon or is light

445
00:23:08,200 --> 00:23:11,760
Speaker 1: kind of the beam of light? Because the photon itself

446
00:23:11,800 --> 00:23:14,600
Speaker 1: doesn't slow down, does it? It just it just gets busier.

447
00:23:14,760 --> 00:23:17,880
Speaker 1: That's right. The photon itself doesn't slow down unless you're

448
00:23:17,960 --> 00:23:21,440
Speaker 1: averaging right, if you're averaging over it's time through the material,

449
00:23:21,520 --> 00:23:24,560
Speaker 1: then its effective speed is slower. So again it's a

450
00:23:24,560 --> 00:23:26,840
Speaker 1: bit technical. But what these folks have done with these

451
00:23:26,880 --> 00:23:29,240
Speaker 1: experiments that we've been hearing about slowing down light and

452
00:23:29,240 --> 00:23:32,400
Speaker 1: stopping light is even something different than that. It's even

453
00:23:32,440 --> 00:23:36,280
Speaker 1: more of a technicality than just slowing down light. Overall,

454
00:23:36,400 --> 00:23:38,760
Speaker 1: there are different ways to slow light down. One as

455
00:23:38,840 --> 00:23:43,040
Speaker 1: you can slow the photon as it goes across the material.

456
00:23:43,200 --> 00:23:45,280
Speaker 1: And then there's another way, which is what these physicists

457
00:23:45,280 --> 00:23:47,439
Speaker 1: have done. Yeah, because slowing things down as it goes

458
00:23:47,480 --> 00:23:50,400
Speaker 1: through material, that's old news. Like Isaac Newton did that, right,

459
00:23:50,720 --> 00:23:53,720
Speaker 1: he used prisms. Everybody is known for years that you

460
00:23:53,760 --> 00:23:56,720
Speaker 1: can slow things down as they move through a material. Right,

461
00:23:56,800 --> 00:23:59,680
Speaker 1: it's old news. That's from the time of Yeah, this

462
00:24:00,000 --> 00:24:01,840
Speaker 1: it's old news. What these folks have done is not

463
00:24:01,920 --> 00:24:04,800
Speaker 1: just slow things down by moving through ice or water

464
00:24:04,960 --> 00:24:08,800
Speaker 1: or blast. That's last centuries physics news. What they've done

465
00:24:08,880 --> 00:24:11,040
Speaker 1: is something different. Or they claim that it's a big

466
00:24:11,040 --> 00:24:13,600
Speaker 1: step forward, all right, well, um, step us store it.

467
00:24:13,680 --> 00:24:16,040
Speaker 1: What have they done? What did these physicists due to

468
00:24:16,200 --> 00:24:19,040
Speaker 1: slow down light? So what they're doing is not slowing

469
00:24:19,040 --> 00:24:21,800
Speaker 1: down like a beam of light by slowing down individual photons.

470
00:24:22,080 --> 00:24:24,399
Speaker 1: What they're doing is they're slowing down sort of a pulse.

471
00:24:24,880 --> 00:24:27,000
Speaker 1: And when you send a pulse of light, it's not

472
00:24:27,080 --> 00:24:30,639
Speaker 1: just one photon, it's like a collection of photons, the

473
00:24:30,680 --> 00:24:34,480
Speaker 1: way like if you send wiggles down a jump rope,

474
00:24:34,720 --> 00:24:37,159
Speaker 1: it's not a single like sign wave doesn't have a

475
00:24:37,200 --> 00:24:41,000
Speaker 1: single frequency. It has a bunch of different frequencies all

476
00:24:41,040 --> 00:24:43,880
Speaker 1: added up inside of it to make that one shape.

477
00:24:44,080 --> 00:24:47,040
Speaker 1: So are we still talking about individual photons? Are we

478
00:24:47,119 --> 00:24:51,000
Speaker 1: just talking about kind of the the shape of the

479
00:24:51,119 --> 00:24:54,359
Speaker 1: light pulse. We're talking about the pulse, but the pulse

480
00:24:54,480 --> 00:24:57,040
Speaker 1: is made up of a bunch of different photons. It's

481
00:24:57,080 --> 00:25:00,680
Speaker 1: like if you have a group of bike riders and

482
00:25:00,800 --> 00:25:02,480
Speaker 1: you send them all out in a pack. You've got

483
00:25:02,520 --> 00:25:05,600
Speaker 1: a hundred of them or something, and they're all biking together.

484
00:25:05,600 --> 00:25:07,480
Speaker 1: You've got some fast ones and some slow ones and

485
00:25:07,480 --> 00:25:09,960
Speaker 1: sort of like the you know, the shape of the

486
00:25:10,000 --> 00:25:13,040
Speaker 1: pack is changing as it travels, and so the whole

487
00:25:13,119 --> 00:25:16,760
Speaker 1: How old are these cyclists. They're twenty three, just like

488
00:25:16,800 --> 00:25:20,640
Speaker 1: you are. So they're excellent shape. Okay, I just want

489
00:25:20,640 --> 00:25:23,280
Speaker 1: to paint a complete picture here, and any of you

490
00:25:23,320 --> 00:25:25,919
Speaker 1: out there who know anything about like Fourier analysis, that

491
00:25:25,920 --> 00:25:28,520
Speaker 1: you can break down wiggles into sort of their component

492
00:25:28,600 --> 00:25:30,720
Speaker 1: frequencies or so you know, if you're like listening to

493
00:25:30,760 --> 00:25:33,080
Speaker 1: audio and you're looking at equalizer, it shows you, like,

494
00:25:33,280 --> 00:25:35,560
Speaker 1: am I hearing the high pitches or the low pitches

495
00:25:35,600 --> 00:25:38,879
Speaker 1: and the medium pitches? All sound is just a bunch

496
00:25:38,880 --> 00:25:42,920
Speaker 1: of combinations of different wiggles at different frequencies. The same

497
00:25:42,960 --> 00:25:44,639
Speaker 1: thing is true for a pulse of light. If you

498
00:25:44,680 --> 00:25:46,760
Speaker 1: want a pulse of light, you have to make some

499
00:25:46,880 --> 00:25:49,359
Speaker 1: high wiggles and some slower wiggles and patch them all

500
00:25:49,400 --> 00:25:52,240
Speaker 1: together to make that pulse. Right. And and is it

501
00:25:52,280 --> 00:25:56,040
Speaker 1: that different photons of different these different frequencies or is

502
00:25:56,080 --> 00:25:59,080
Speaker 1: it okay? Yes? And so what these researchers have done

503
00:25:59,560 --> 00:26:03,040
Speaker 1: is not slow down individual photons, because that's old news,

504
00:26:03,359 --> 00:26:06,360
Speaker 1: is to try to slow down this whole pulse. To say,

505
00:26:06,480 --> 00:26:10,879
Speaker 1: if we're gonna like send information through fiber optics or whatever,

506
00:26:11,160 --> 00:26:14,120
Speaker 1: you do that by sending pulses of information, you flick

507
00:26:14,200 --> 00:26:16,320
Speaker 1: the switch on and off and that sense whole. But

508
00:26:16,440 --> 00:26:19,680
Speaker 1: a grouping of photons that's a that's a pulse. That's

509
00:26:19,680 --> 00:26:22,159
Speaker 1: a pulse. And so what these experiments are focused on

510
00:26:22,240 --> 00:26:24,440
Speaker 1: is taking one of those pulses and trying to make

511
00:26:24,440 --> 00:26:27,760
Speaker 1: it go more slowly through a material the entire pulse.

512
00:26:28,280 --> 00:26:30,240
Speaker 1: And the key thing there is that, as you said,

513
00:26:30,280 --> 00:26:33,480
Speaker 1: the pulse is made of photons at different frequencies, So

514
00:26:33,520 --> 00:26:36,200
Speaker 1: you've got some that wiggle fast and some the wiggle slow.

515
00:26:36,600 --> 00:26:38,680
Speaker 1: And that's the key idea, because what they do is

516
00:26:38,720 --> 00:26:43,080
Speaker 1: they construct some crazy material, some weird quantum material or

517
00:26:43,119 --> 00:26:46,280
Speaker 1: something where the speed of light through the material is

518
00:26:46,440 --> 00:26:50,639
Speaker 1: different for different frequencies. So the light is slowed down

519
00:26:50,760 --> 00:26:53,119
Speaker 1: differently based on how much it wiggles, Like the really

520
00:26:53,160 --> 00:26:56,400
Speaker 1: blue light is slowed down more than the really red light.

521
00:26:56,720 --> 00:26:59,199
Speaker 1: So it's not that they slowed light down, is that

522
00:26:59,240 --> 00:27:04,399
Speaker 1: they made a material that selectively slows different frequencies. Yes,

523
00:27:04,800 --> 00:27:08,080
Speaker 1: And the consequence is that you like spread out the pulse,

524
00:27:08,440 --> 00:27:10,400
Speaker 1: like you have that group of riders and you said,

525
00:27:10,400 --> 00:27:12,120
Speaker 1: all right, I'm gonna make all the old people ride

526
00:27:12,119 --> 00:27:14,840
Speaker 1: more slowly. Now, then they're gonna start to fall behind,

527
00:27:14,880 --> 00:27:17,919
Speaker 1: and the pulse of riders, this group of bikers is

528
00:27:17,920 --> 00:27:20,080
Speaker 1: going to get more and more spread out, and so

529
00:27:20,200 --> 00:27:23,800
Speaker 1: when the trailing edge of the pulse arrives is going

530
00:27:23,840 --> 00:27:26,080
Speaker 1: to be later, and so sort of the whole pulse

531
00:27:26,160 --> 00:27:30,440
Speaker 1: takes longer to get there. Uh, you stretched it out.

532
00:27:30,760 --> 00:27:33,400
Speaker 1: When it gets there later, well you stretched it out

533
00:27:33,400 --> 00:27:35,000
Speaker 1: and sort of so if you look at like where

534
00:27:35,040 --> 00:27:37,439
Speaker 1: the peak of the pulse is, it moves back because

535
00:27:37,600 --> 00:27:40,919
Speaker 1: part of the pulse got stretched backwards. But doesn't that

536
00:27:41,000 --> 00:27:43,720
Speaker 1: happen normally when you shoot light through glass or ice?

537
00:27:44,000 --> 00:27:46,960
Speaker 1: Doesn't it normally get spread out? It does normally get

538
00:27:46,960 --> 00:27:50,199
Speaker 1: spread out because there's this dispersion relationship, that's what we

539
00:27:50,240 --> 00:27:54,280
Speaker 1: call it, where the slowing downiness depends on the frequency.

540
00:27:54,280 --> 00:27:56,840
Speaker 1: And that's how a prism works, right. A prism works

541
00:27:56,840 --> 00:27:59,760
Speaker 1: because you shoot light into it and the mount that

542
00:28:00,040 --> 00:28:03,200
Speaker 1: it bends depends on this frequency and that's the same

543
00:28:03,200 --> 00:28:06,000
Speaker 1: thing that down so it spreads out exactly, And so

544
00:28:06,359 --> 00:28:08,640
Speaker 1: is what have they done? Then? That's different? Well, these

545
00:28:08,680 --> 00:28:13,280
Speaker 1: materials have like a very strong dispersion. It's like extremely

546
00:28:13,840 --> 00:28:17,600
Speaker 1: extra extra so you can Yeah, so you can shoot

547
00:28:17,640 --> 00:28:19,640
Speaker 1: like a laser, like let's say you want to slow

548
00:28:19,640 --> 00:28:21,640
Speaker 1: it do on a laser pulse. A laser pulse has

549
00:28:21,680 --> 00:28:24,159
Speaker 1: a bunch of frequencies really close together. Because you know,

550
00:28:24,160 --> 00:28:26,720
Speaker 1: a laser is usually like a single color, so it's

551
00:28:26,720 --> 00:28:29,359
Speaker 1: all a bunch of really tightly packed frequencies, it's harder

552
00:28:29,400 --> 00:28:31,640
Speaker 1: to spread out. So what they've done is developed these

553
00:28:31,680 --> 00:28:35,320
Speaker 1: materials where the dispersion is really strong. So even a

554
00:28:35,400 --> 00:28:38,720
Speaker 1: tightly packed laser pulse, which is a bunch of frequencies

555
00:28:38,760 --> 00:28:41,640
Speaker 1: really similar to each other, gets spread out and effectively

556
00:28:41,680 --> 00:28:45,560
Speaker 1: slowed down. It gets blurry. Yeah, yeah, so it gets blurry.

557
00:28:45,720 --> 00:28:47,760
Speaker 1: You smush it. You just gonna smooche the laser. But

558
00:28:47,800 --> 00:28:50,640
Speaker 1: then you know, But then, but like the leading edge

559
00:28:50,680 --> 00:28:53,120
Speaker 1: of the poles, like the first electrons that go in

560
00:28:53,880 --> 00:28:56,680
Speaker 1: there are the fastest, still come out the other side

561
00:28:57,040 --> 00:28:59,800
Speaker 1: as fast as they can. Yeah, the first photons get

562
00:28:59,840 --> 00:29:02,560
Speaker 1: there um at a very high speed. It's not exactly

563
00:29:02,560 --> 00:29:05,200
Speaker 1: the speed of light, because every photon is slowed down

564
00:29:05,200 --> 00:29:06,880
Speaker 1: as it goes through a material for the reasons we

565
00:29:06,960 --> 00:29:09,640
Speaker 1: talked about before. But you're right there. The difference now

566
00:29:09,640 --> 00:29:12,400
Speaker 1: in the speed between the leading edge and the trailing edge.

567
00:29:12,600 --> 00:29:14,400
Speaker 1: And this is where it gets kind of technical. These

568
00:29:14,400 --> 00:29:18,000
Speaker 1: folks talk not about phase velocity, which is a velocity

569
00:29:18,040 --> 00:29:21,320
Speaker 1: of any individual photon in the pulse, a group velocity,

570
00:29:21,320 --> 00:29:23,960
Speaker 1: which is like where is the location of the peak

571
00:29:23,960 --> 00:29:26,920
Speaker 1: half ast is the peak moving. It's like slowing light

572
00:29:26,960 --> 00:29:29,960
Speaker 1: down in the sense that in the sense of what

573
00:29:30,040 --> 00:29:34,960
Speaker 1: happens when you slow down a song or the audio

574
00:29:35,080 --> 00:29:39,560
Speaker 1: of of somebody speaking, it's just goods sort of you know,

575
00:29:39,920 --> 00:29:43,320
Speaker 1: more on the lower it gets blurrier, and it gets

576
00:29:43,360 --> 00:29:48,120
Speaker 1: more in the lower tones. You know, goods slow. But

577
00:29:48,680 --> 00:29:52,800
Speaker 1: they're not technically slowing down the sound pulled the wave.

578
00:29:53,080 --> 00:29:55,400
Speaker 1: They're just kind of spreading it out. And so that's

579
00:29:55,440 --> 00:29:58,760
Speaker 1: what they mean by slowing light down. Yeah, that's what

580
00:29:58,800 --> 00:30:01,880
Speaker 1: they mean by slowing down light. And so you're gonna

581
00:30:01,880 --> 00:30:04,400
Speaker 1: be like clever lawyers, clever lawyers, you gotta sort of

582
00:30:04,440 --> 00:30:06,880
Speaker 1: dig and several layers there before you figure out, like

583
00:30:06,920 --> 00:30:09,560
Speaker 1: what do you really mean by slowing down? Like it

584
00:30:09,640 --> 00:30:12,400
Speaker 1: is sort of more like slowing down in the audio sense, right,

585
00:30:12,440 --> 00:30:16,760
Speaker 1: like you're slowing down a song or speech. Yes, in

586
00:30:16,800 --> 00:30:19,160
Speaker 1: the sense of audio, like the analogy would be that

587
00:30:19,200 --> 00:30:22,600
Speaker 1: you're extending the wavelength of every part of that sound.

588
00:30:23,160 --> 00:30:26,120
Speaker 1: But then you know, as I say to you, hey, Jorge, um,

589
00:30:26,280 --> 00:30:29,760
Speaker 1: you're slowing down like the lower frequencies even more so,

590
00:30:29,880 --> 00:30:32,720
Speaker 1: like you not not only would it sound deeper, would

591
00:30:32,760 --> 00:30:35,400
Speaker 1: I sound more like you know, al green? But also

592
00:30:35,800 --> 00:30:38,520
Speaker 1: the length of the Jorge phrase would take longer to

593
00:30:38,520 --> 00:30:40,480
Speaker 1: get there because the trailing edge of it would take

594
00:30:40,520 --> 00:30:47,000
Speaker 1: longer because you're slowing down the even lower bits. Folks.

595
00:30:47,040 --> 00:30:48,680
Speaker 1: And that was not just Jorge ad living. That was

596
00:30:48,760 --> 00:30:52,920
Speaker 1: actual scientific experimentation, right. That wasn't me burping a banana.

597
00:30:53,640 --> 00:30:57,920
Speaker 1: That was an actual physics. Yeah. And there's one group

598
00:30:58,200 --> 00:31:01,400
Speaker 1: that claims to have even stopped light. Okay, let's get

599
00:31:01,400 --> 00:31:04,800
Speaker 1: into this idea, and maybe you can stop light. That's

600
00:31:04,800 --> 00:31:20,720
Speaker 1: pretty crazy. But first let's take a quick break. Okay,

601
00:31:20,720 --> 00:31:23,640
Speaker 1: so my lawyer says I can slow light down if

602
00:31:23,680 --> 00:31:26,360
Speaker 1: by slowing down I mean like spreading out the wavelengths

603
00:31:26,360 --> 00:31:30,640
Speaker 1: and making it just sort of smooshier. But you're saying

604
00:31:30,680 --> 00:31:34,320
Speaker 1: some scientists can actually or have claim to have actually

605
00:31:34,320 --> 00:31:37,880
Speaker 1: stopped light. Yes, and this is a physics topic, which

606
00:31:37,880 --> 00:31:41,080
Speaker 1: is sort of amazing and then also like sort of

607
00:31:41,120 --> 00:31:44,040
Speaker 1: disappointing and nonsensical because I feel like I stopped light

608
00:31:44,120 --> 00:31:47,760
Speaker 1: all the time. Just you know, I've always been able

609
00:31:47,800 --> 00:31:50,200
Speaker 1: to do that. Half of that power. I just go

610
00:31:50,280 --> 00:31:52,920
Speaker 1: outside and I seem to stop all the light from

611
00:31:52,920 --> 00:31:55,000
Speaker 1: the sun. You do make a better door than a window.

612
00:31:55,040 --> 00:31:57,560
Speaker 1: It's true. I cast a long shadow that you. Well,

613
00:31:57,560 --> 00:31:59,600
Speaker 1: what these folks did when they say they stop light

614
00:31:59,680 --> 00:32:02,280
Speaker 1: is they shoot a laser into some kind of material

615
00:32:03,240 --> 00:32:06,840
Speaker 1: and then the laser gets absorbed by that material, and

616
00:32:06,880 --> 00:32:09,160
Speaker 1: then they can flick a switch and the beam shoots

617
00:32:09,160 --> 00:32:12,240
Speaker 1: back out the other side and an arbitrary later moment. Okay,

618
00:32:12,280 --> 00:32:14,280
Speaker 1: that does sound pretty cool. It sounds pretty cool. They're

619
00:32:14,280 --> 00:32:17,160
Speaker 1: like shoot a beam in, it gets like absorbed, it

620
00:32:17,200 --> 00:32:20,080
Speaker 1: gets he stored, and you can wait like you know,

621
00:32:20,480 --> 00:32:24,080
Speaker 1: a second, an hour, a day, and then you flip

622
00:32:24,080 --> 00:32:26,960
Speaker 1: another laser switch and then the beam shoots it back

623
00:32:26,960 --> 00:32:29,200
Speaker 1: out the other side. Wow, Like, did they trapped it

624
00:32:29,240 --> 00:32:31,040
Speaker 1: inside of this material and then they can let it

625
00:32:31,040 --> 00:32:34,200
Speaker 1: go later? Yes, they've trapped inside the material. All right,

626
00:32:34,240 --> 00:32:36,480
Speaker 1: I mean I'm intrigued. You might ask like, well, did

627
00:32:36,480 --> 00:32:39,280
Speaker 1: they stop the photons? Like and no, of course they

628
00:32:39,280 --> 00:32:41,800
Speaker 1: can't stop the photons. It's not like if they zoomed

629
00:32:41,800 --> 00:32:44,440
Speaker 1: in with a microscope they could see these photons just

630
00:32:44,480 --> 00:32:47,600
Speaker 1: like sitting there. They didn't freeze them, right, they didn't

631
00:32:47,640 --> 00:32:50,640
Speaker 1: freeze the photons. What's that comic book character with the

632
00:32:50,720 --> 00:32:54,960
Speaker 1: with the freezing powers? Oh? Mr Freeze did you just

633
00:32:55,000 --> 00:32:59,120
Speaker 1: make that up? And over see? I tell you they

634
00:32:59,200 --> 00:33:01,560
Speaker 1: right if out of I what's that guy with the

635
00:33:01,600 --> 00:33:04,640
Speaker 1: cartoon powers for particle physics? Is it? Mr particle Physics

636
00:33:04,680 --> 00:33:08,800
Speaker 1: booms exactly? That's how clever that idea sounds. Anyway, Mr

637
00:33:08,840 --> 00:33:11,480
Speaker 1: Freeze didn't like Mr Freeze. These photons, we can like

638
00:33:11,520 --> 00:33:13,480
Speaker 1: look at them covered in ice or anything. What do

639
00:33:13,560 --> 00:33:16,200
Speaker 1: they do? They keep them busy, or they record them

640
00:33:16,360 --> 00:33:21,120
Speaker 1: or what they get. I feel like that comes comes

641
00:33:21,160 --> 00:33:23,320
Speaker 1: from parenting. You're like, all right, I'm gonna run all

642
00:33:23,320 --> 00:33:25,560
Speaker 1: these crazy kids into this room, keep them busy, and

643
00:33:25,560 --> 00:33:28,160
Speaker 1: they'll shoot out the other side. Here's my phone if

644
00:33:28,280 --> 00:33:30,120
Speaker 1: if you want to see a room full of children,

645
00:33:30,280 --> 00:33:34,200
Speaker 1: slow down and maybe Freeze just hand them your phone. Yeah.

646
00:33:34,240 --> 00:33:37,760
Speaker 1: They just have a little phone for these for these photons. Yeah,

647
00:33:37,920 --> 00:33:42,320
Speaker 1: there you go, and these phones admit photons. Now now

648
00:33:42,400 --> 00:33:45,120
Speaker 1: it is getting too deep. Yeah. Essentially, what they do

649
00:33:45,200 --> 00:33:47,480
Speaker 1: is they build some system that can absorb the light,

650
00:33:47,840 --> 00:33:51,360
Speaker 1: store the information from that light, and then re emit

651
00:33:51,440 --> 00:33:54,840
Speaker 1: it at an arbitrary later time based on some external input.

652
00:33:55,120 --> 00:34:00,000
Speaker 1: Isn't that called a camera? Yes, exactly exactly. So I'm

653
00:34:00,040 --> 00:34:03,360
Speaker 1: one sense, it's like, wow, that's awesome. This cloud of

654
00:34:03,600 --> 00:34:05,920
Speaker 1: atoms absorbed this laser and can re emit it. On

655
00:34:05,920 --> 00:34:09,160
Speaker 1: the other hand, like, well, every photograph is basically stopping

656
00:34:09,239 --> 00:34:12,560
Speaker 1: light and later re emitting it. Um. So in one

657
00:34:12,600 --> 00:34:15,520
Speaker 1: sense it's awesome because it's something that nobody's ever done before,

658
00:34:15,520 --> 00:34:18,799
Speaker 1: and another sense, it is accomplishing something we've been doing forever. Well,

659
00:34:18,840 --> 00:34:23,960
Speaker 1: I mean, a photograph and the TV is pretty complicated, right,

660
00:34:24,000 --> 00:34:26,799
Speaker 1: because you need all these different things. But it might

661
00:34:26,840 --> 00:34:28,520
Speaker 1: get in the sense and maybe these guys did it

662
00:34:28,760 --> 00:34:31,280
Speaker 1: in a much more fundamental sense, like they actually build

663
00:34:31,280 --> 00:34:34,120
Speaker 1: a material that takes a photographs and and admits it. Well,

664
00:34:34,160 --> 00:34:37,000
Speaker 1: I wouldn't say it's less complicated, Like I think a

665
00:34:37,080 --> 00:34:39,799
Speaker 1: camera and a screen is less complicated than having like

666
00:34:39,880 --> 00:34:44,120
Speaker 1: you know, um Millie kelvin refrigerator and high intensity lasers.

667
00:34:44,560 --> 00:34:46,600
Speaker 1: But this thing does it sort of all at once,

668
00:34:46,760 --> 00:34:49,600
Speaker 1: like it both absorbs the photons and then later re

669
00:34:49,680 --> 00:34:53,280
Speaker 1: emits it. It's not like it's you know, stored electronically

670
00:34:53,360 --> 00:34:56,959
Speaker 1: and then regenerated. But again you might say it's still

671
00:34:56,960 --> 00:34:59,319
Speaker 1: it's not the same photons, like they were absorbed by

672
00:34:59,320 --> 00:35:02,920
Speaker 1: the material and then re emitted. Is it the same photons?

673
00:35:03,040 --> 00:35:04,960
Speaker 1: Not really stem me through it? What did they do?

674
00:35:05,160 --> 00:35:07,920
Speaker 1: How does this material work. Well. They used a Bose

675
00:35:08,040 --> 00:35:12,320
Speaker 1: Einstein condensate, which is a very cold collection of atoms

676
00:35:12,600 --> 00:35:15,120
Speaker 1: in a really weird quantum state. We'll do a whole

677
00:35:15,160 --> 00:35:18,080
Speaker 1: podcast on what a Bose Einstein condensate is. But what

678
00:35:18,120 --> 00:35:20,399
Speaker 1: they did is they shoot a laser into it from

679
00:35:20,400 --> 00:35:23,160
Speaker 1: the side and then that's sort of like holds it.

680
00:35:23,400 --> 00:35:25,480
Speaker 1: What do you mean, hold it? Like it the light

681
00:35:25,600 --> 00:35:28,839
Speaker 1: is absorbed by the atoms and the condensate, and then

682
00:35:28,880 --> 00:35:30,799
Speaker 1: they just sort of hold it. This first laser is

683
00:35:30,840 --> 00:35:33,040
Speaker 1: like the switch laser, just like gets the atoms in

684
00:35:33,040 --> 00:35:35,239
Speaker 1: the right situation and puts them in the right sort

685
00:35:35,280 --> 00:35:37,680
Speaker 1: of quantum state to do this trick. Then they have

686
00:35:37,719 --> 00:35:40,120
Speaker 1: the second laser, the one they actually want to absorb

687
00:35:40,200 --> 00:35:43,000
Speaker 1: and re emit. They fire that into this pile of

688
00:35:43,000 --> 00:35:46,160
Speaker 1: atoms and then it gets absorbed and then when they

689
00:35:46,200 --> 00:35:48,040
Speaker 1: want to release it, they just turn off the first

690
00:35:48,120 --> 00:35:51,000
Speaker 1: laser and then it emits the pulse from the second

691
00:35:51,080 --> 00:35:53,680
Speaker 1: laser in the same direction and with the same shape

692
00:35:53,680 --> 00:35:56,839
Speaker 1: and intensity everything. Yeah, precisely, and you know, there's some

693
00:35:56,960 --> 00:36:00,480
Speaker 1: loss of information there, but mostly it captures the you know, light.

694
00:36:00,640 --> 00:36:03,160
Speaker 1: That is pretty cool. I think that it's pretty awesome.

695
00:36:03,960 --> 00:36:06,520
Speaker 1: Otherwise it's just a superpower that only a comic book

696
00:36:06,600 --> 00:36:13,160
Speaker 1: character Mr. Light Freezer would have. Mr. Laser Freeze. Okay,

697
00:36:13,200 --> 00:36:15,560
Speaker 1: so oh wow, so um, I mean that that sounds

698
00:36:15,560 --> 00:36:18,760
Speaker 1: pretty impressive that you shoot it and then the atoms themselves,

699
00:36:18,800 --> 00:36:22,560
Speaker 1: not some like memory or some electronic it's like the

700
00:36:22,600 --> 00:36:27,960
Speaker 1: atoms themselves somehow remember this laser and then admit it

701
00:36:28,080 --> 00:36:30,879
Speaker 1: when you want to wanted to in the same way

702
00:36:30,880 --> 00:36:33,000
Speaker 1: that it came in. Yeah, that is pretty cool, And

703
00:36:33,040 --> 00:36:35,959
Speaker 1: I think it's awesome that people just try to make

704
00:36:36,160 --> 00:36:39,200
Speaker 1: materials do new stuff, Like does this whole field of

705
00:36:39,239 --> 00:36:42,160
Speaker 1: you know, atomic physics and condensed matter physics where people

706
00:36:42,160 --> 00:36:44,200
Speaker 1: are like, hey, can we make some new kind of

707
00:36:44,239 --> 00:36:47,120
Speaker 1: goo that has this weird property? Can make some new

708
00:36:47,200 --> 00:36:49,319
Speaker 1: kind of good that has that weird property. And it's

709
00:36:49,320 --> 00:36:51,600
Speaker 1: sort of just like an exploration of the way things

710
00:36:51,719 --> 00:36:54,359
Speaker 1: can be in the universe. And you know, we're used

711
00:36:54,400 --> 00:36:58,000
Speaker 1: to like different kinds of stuff water, metals, rocks, whatever,

712
00:36:58,280 --> 00:37:01,360
Speaker 1: but it's possible that there's all different kinds of stuff

713
00:37:01,360 --> 00:37:03,840
Speaker 1: in the universe that we've never experienced just because doesn't

714
00:37:03,880 --> 00:37:06,560
Speaker 1: occur naturally here on Earth. So these folks are like

715
00:37:06,600 --> 00:37:09,399
Speaker 1: pushing the boundaries right, they're trying to make things do

716
00:37:09,520 --> 00:37:12,560
Speaker 1: new things. Yes, exactly, they're trying to bring the rules.

717
00:37:12,600 --> 00:37:15,399
Speaker 1: They're like, well, nobody thought things could do this, Let's

718
00:37:15,400 --> 00:37:17,839
Speaker 1: see if we can make it work. It's kind of like,

719
00:37:18,239 --> 00:37:20,480
Speaker 1: you know, nobody ever thought you could walk on water,

720
00:37:20,840 --> 00:37:22,279
Speaker 1: but hey, it turns out if you freeze it, you

721
00:37:22,280 --> 00:37:25,239
Speaker 1: can walk on water. Yes, And in some sense it's

722
00:37:25,280 --> 00:37:28,680
Speaker 1: as unsatisfying as that. It's like, are you really walking

723
00:37:28,680 --> 00:37:31,279
Speaker 1: on water if you're walking on a frozen lake? Technically yes,

724
00:37:33,160 --> 00:37:34,960
Speaker 1: what have you shoot a lasers through it? Is it

725
00:37:35,040 --> 00:37:39,200
Speaker 1: still technically a miracle? Well, you know, if you're ice skating,

726
00:37:39,239 --> 00:37:41,879
Speaker 1: then you're walking water because you're making this very thin

727
00:37:42,440 --> 00:37:45,200
Speaker 1: layer of water between your blades and the ice. So

728
00:37:45,480 --> 00:37:50,800
Speaker 1: you know, there you go. More Jesus lawyer. And people

729
00:37:50,800 --> 00:37:53,040
Speaker 1: try to say, maybe there's some application to this, like

730
00:37:53,440 --> 00:37:56,160
Speaker 1: if you could slow down light, you could make circuits

731
00:37:56,200 --> 00:38:00,320
Speaker 1: that use less power or something interesting. Yeah, rank Frankly,

732
00:38:00,360 --> 00:38:02,440
Speaker 1: I don't find any of that convincing. I think that

733
00:38:02,520 --> 00:38:04,799
Speaker 1: the motivation for this is like, hey, can we make

734
00:38:04,880 --> 00:38:08,200
Speaker 1: something in the universe that's weird and different? And I

735
00:38:08,239 --> 00:38:10,319
Speaker 1: think there's there's a there's a lot of value to

736
00:38:10,360 --> 00:38:12,839
Speaker 1: that well, there's a lot of applications that they say

737
00:38:12,960 --> 00:38:17,680
Speaker 1: so in solid state physics, where if you get these

738
00:38:17,719 --> 00:38:20,840
Speaker 1: materials to do these weird things, that they could maybe

739
00:38:20,840 --> 00:38:23,719
Speaker 1: be the basis for like a quantum computer. Yeah, precisely,

740
00:38:24,040 --> 00:38:27,160
Speaker 1: there are ways and you could find applications for materials

741
00:38:27,160 --> 00:38:30,200
Speaker 1: that do weird stuff. And you know, people were building

742
00:38:30,280 --> 00:38:33,520
Speaker 1: atom traps and bose Einstein particles for years before they

743
00:38:33,520 --> 00:38:35,640
Speaker 1: had ideas for how to apply them. So it's a

744
00:38:35,640 --> 00:38:38,239
Speaker 1: good idea to develop new kinds of materials because they

745
00:38:38,280 --> 00:38:41,359
Speaker 1: can inspire new applications. And sometimes you work on something

746
00:38:41,400 --> 00:38:44,120
Speaker 1: for ten years and then people realize, hey, that's exactly

747
00:38:44,120 --> 00:38:47,399
Speaker 1: what we needed for this other totally unrelated problem. So

748
00:38:47,480 --> 00:38:49,440
Speaker 1: you know, we want to make progress as a species,

749
00:38:49,440 --> 00:38:52,200
Speaker 1: we've got to like explore broadly and try all sorts

750
00:38:52,200 --> 00:38:54,479
Speaker 1: of weird stuff. And you never know, like it could

751
00:38:54,480 --> 00:38:57,400
Speaker 1: have been that they didn't make light stop, but something

752
00:38:57,440 --> 00:39:01,440
Speaker 1: else totally weird and unexpected happened and discovered something crazy.

753
00:39:01,719 --> 00:39:03,879
Speaker 1: You never know. When you do research right or just

754
00:39:03,960 --> 00:39:06,560
Speaker 1: that improving these things, you learn something new about the

755
00:39:06,600 --> 00:39:10,759
Speaker 1: materials themselves, or how atoms are like behave, or if

756
00:39:10,840 --> 00:39:12,920
Speaker 1: in order to make this happen. You have to invent

757
00:39:13,000 --> 00:39:15,160
Speaker 1: something new and weird and that turns out to be

758
00:39:15,200 --> 00:39:17,560
Speaker 1: really useful for something else, you know, like the whole

759
00:39:17,560 --> 00:39:22,480
Speaker 1: semiconductor industry and computers exist because of basic research into

760
00:39:22,520 --> 00:39:25,600
Speaker 1: stuff that wasn't motivated at building computers. Like, for example,

761
00:39:25,640 --> 00:39:27,560
Speaker 1: I just got this great idea to shoot myself with

762
00:39:27,600 --> 00:39:31,680
Speaker 1: a laser to stop aging or at least on my knees.

763
00:39:33,360 --> 00:39:35,600
Speaker 1: There is laser therapy for everything, Like you can get

764
00:39:35,640 --> 00:39:38,560
Speaker 1: laser therapy to like stop smoking. I wonder, like what

765
00:39:38,640 --> 00:39:43,520
Speaker 1: part do you are they sting with the laser? Probably

766
00:39:43,560 --> 00:39:49,240
Speaker 1: your wallet and your Yeah, I don't know. I wouldn't

767
00:39:49,239 --> 00:39:52,040
Speaker 1: recommend any of those laser treatments. Okay, well it is.

768
00:39:52,160 --> 00:39:55,719
Speaker 1: It does sound like they maybe have technically slowed down

769
00:39:55,800 --> 00:39:59,160
Speaker 1: light and maybe sort of in a ways stop light.

770
00:39:59,320 --> 00:40:01,920
Speaker 1: So that's pretty pretty interesting, pretty cool. It's pretty cool.

771
00:40:01,960 --> 00:40:05,040
Speaker 1: They've definitely done something nobody has done before. And today

772
00:40:05,040 --> 00:40:07,000
Speaker 1: we only talked about a couple of groups doing a

773
00:40:07,000 --> 00:40:09,279
Speaker 1: couple of experiments, but it's a big field and people

774
00:40:09,280 --> 00:40:11,080
Speaker 1: are doing it will all sorts of new kinds of

775
00:40:11,120 --> 00:40:14,200
Speaker 1: materials and in new ways, and applying it to different

776
00:40:14,239 --> 00:40:17,080
Speaker 1: kinds of light and higher intensity, lower intensity, and bigger

777
00:40:17,080 --> 00:40:20,719
Speaker 1: packets and smaller packets. We couldn't possibly review all the

778
00:40:20,760 --> 00:40:23,879
Speaker 1: recent work on it. It's a whole burgeoning industry. All right. Well,

779
00:40:23,920 --> 00:40:25,719
Speaker 1: I think that answers that question that a lot of

780
00:40:25,719 --> 00:40:28,160
Speaker 1: people wrote in about you can slow down light and

781
00:40:28,200 --> 00:40:31,160
Speaker 1: you can stop light. Have you defined things in the

782
00:40:31,239 --> 00:40:35,160
Speaker 1: right way and use both speakers? Was that the main

783
00:40:35,239 --> 00:40:38,320
Speaker 1: lesson here? Yes? And so if you find a bottle

784
00:40:38,360 --> 00:40:40,839
Speaker 1: and the genie comes out and he's a physicist, and

785
00:40:40,880 --> 00:40:43,880
Speaker 1: you ask for some new special power, make sure you

786
00:40:43,880 --> 00:40:47,720
Speaker 1: are very clear about what you're asking for, because these

787
00:40:47,719 --> 00:40:50,080
Speaker 1: physicists will find a way to squirrel out of it

788
00:40:50,120 --> 00:40:52,279
Speaker 1: and not give you what you were hoping for. Right,

789
00:40:52,360 --> 00:40:54,120
Speaker 1: You might just hand you a six pack of light

790
00:40:54,160 --> 00:40:58,040
Speaker 1: beer and then you say your way. This light will

791
00:40:58,040 --> 00:41:02,680
Speaker 1: make you slow down. That's one way to slow down. There,

792
00:41:02,719 --> 00:41:06,040
Speaker 1: you go do that a laser and you can sell

793
00:41:06,080 --> 00:41:07,719
Speaker 1: it for a lot more. Yeah, you don't want us

794
00:41:07,719 --> 00:41:10,040
Speaker 1: as your physics genies may that that's what would make

795
00:41:10,040 --> 00:41:12,200
Speaker 1: hell a little bit more tolerable. Sin, you can freeze

796
00:41:12,239 --> 00:41:14,279
Speaker 1: some beer down and that you can drink it with

797
00:41:14,440 --> 00:41:17,080
Speaker 1: the physicists. All right, Well, thank you very much to

798
00:41:17,080 --> 00:41:20,360
Speaker 1: everybody who wrote in to ask us about this weird headline.

799
00:41:20,560 --> 00:41:23,680
Speaker 1: And if you read something online about weird discoveries and

800
00:41:23,719 --> 00:41:25,759
Speaker 1: physics or something you're not quite sure about, send it

801
00:41:25,800 --> 00:41:27,759
Speaker 1: to us. We will break it down for you. You

802
00:41:27,800 --> 00:41:30,040
Speaker 1: hope you enjoyed that. Thanks for listening. Let's see you

803
00:41:30,080 --> 00:41:40,360
Speaker 1: next time. Before you still have a question after listening

804
00:41:40,400 --> 00:41:43,480
Speaker 1: to all these explanations, please drop us a line. We'd

805
00:41:43,520 --> 00:41:46,360
Speaker 1: love to hear from you. You can find us on Facebook, Twitter,

806
00:41:46,440 --> 00:41:50,120
Speaker 1: and Instagram at Daniel and Jorge That's one word, or

807
00:41:50,200 --> 00:41:54,160
Speaker 1: email us at Feedback at Daniel and Jorge dot com.

808
00:41:54,160 --> 00:41:57,000
Speaker 1: Thanks for listening, and remember that Daniel and Jorge explained.

809
00:41:57,040 --> 00:42:00,319
Speaker 1: The Universe is a production of I Heart Radio More

810
00:42:00,400 --> 00:42:03,360
Speaker 1: podcast from my Heart Radio. Visit the I heart Radio

811
00:42:03,440 --> 00:42:07,440
Speaker 1: Apple podcasts or wherever you listen to your favorite shows.

812
00:42:12,440 --> 00:42:12,840
Speaker 1: Yeah