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How Lasers Work · Stuff You Should Know

• 0:01
  Speaker 1: Welcome to Stuff you should know, a production of IHEARTRADIOW.
• 0:11
  Speaker 2: And welcome to the podcast. I'm Josh, and there's Chuck
• 0:14
  Speaker 2: and Jerry's here too. And she was making too many
• 0:17
  Speaker 2: laser noises, so we asked her to please go on
• 0:20
  Speaker 2: you because she did, and I assume she's still making
• 0:22
  Speaker 2: laser noises. We just can't hear right now.
• 0:25
  Speaker 1: You have a little attitude about it.
• 0:26
  Speaker 2: Too, she did. I mean, I was really mean and kurt,
• 0:30
  Speaker 2: but she didn't have to be that way back.
• 0:33
  Speaker 1: Yeah, this is a one way street, right, it's.
• 0:37
  Speaker 2: My way or the highway.
• 0:40
  Speaker 1: You know, it's about time we did an episode on lasers.
• 0:44
  Speaker 1: This seems like something that we would have tackled in
• 0:47
  Speaker 1: those first formative in that first formative decade, and.
• 0:51
  Speaker 2: I'm glad we didn't because I think it's good to
• 0:53
  Speaker 2: still do like a traditional you know, how X works episode,
• 0:59
  Speaker 2: we should do one, And how X works it depends
• 1:03
  Speaker 2: on what kind of X you're talking about.
• 1:05
  Speaker 1: Ruby used to give us an X when she was little,
• 1:08
  Speaker 1: when she was like two years old. If she didn't
• 1:10
  Speaker 1: like something, she would do her fingers as an X.
• 1:13
  Speaker 2: And she just keeps getting cooler and cooler.
• 1:15
  Speaker 1: She forgot that she lost that one along the way.
• 1:17
  Speaker 1: I told her to bring that back.
• 1:19
  Speaker 2: Yeah, that's a good one.
• 1:19
  Speaker 1: Uncle Josh likes it.
• 1:21
  Speaker 2: That's like talk to the hand, but way better.
• 1:23
  Speaker 1: Yeah, exactly.
• 1:26
  Speaker 2: All right, So we're talking lasers today, not necessarily X.
• 1:31
  Speaker 2: Maybe we will do X someday. Let's find out, okay,
• 1:34
  Speaker 2: And everybody knows what a laser is, right.
• 1:36
  Speaker 1: Yeah, I mean I feel like it's one of the
• 1:38
  Speaker 1: more like one of those acronyms like scuba that you
• 1:41
  Speaker 1: learn when you're like on the playground. M hm. So
• 1:45
  Speaker 1: in this case, it stands for light amplification by stimulated
• 1:50
  Speaker 1: emission of radiation. And now that I know what a
• 1:53
  Speaker 1: laser is and how it works, they kind of nailed
• 1:55
  Speaker 1: it with that acronym they did.
• 1:58
  Speaker 2: You you can totally forgive them for the B and
• 2:00
  Speaker 2: the of because that's a world class acronym.
• 2:03
  Speaker 1: Yeah, that would be lab sere if they included those
• 2:10
  Speaker 1: lasers so much cooler.
• 2:12
  Speaker 2: Lab se or doesn't. It doesn't have that same ring
• 2:14
  Speaker 2: to it as laser.
• 2:15
  Speaker 1: Throw me the lab se or gun.
• 2:18
  Speaker 2: That someone would say. No. So, lasers are everywhere everybody,
• 2:24
  Speaker 2: They're all around you. A lot of them are pointed
• 2:26
  Speaker 2: at you right now, you just can't see them. But
• 2:30
  Speaker 2: like a UPC code scanner at a supermarket checkout. They
• 2:33
  Speaker 2: still have supermarkets, right, Oh yeah, that's right. Everyone goes
• 2:37
  Speaker 2: in and empties all of their bank accounts into them
• 2:40
  Speaker 2: every week to get suesstenates. Well, when you check out,
• 2:43
  Speaker 2: boo boo boop like that, that's actually a laser being triggered.
• 2:49
  Speaker 2: You're scanning your UPC code. So lasers are everywhere. They're
• 2:53
  Speaker 2: at the supermarket. At least, that doesn't necessarily mean you
• 2:56
  Speaker 2: understand them. I didn't understand them until we started to
• 2:59
  Speaker 2: research this, did you know.
• 3:01
  Speaker 1: And it's really not that hard to wrap your head around.
• 3:04
  Speaker 1: Actually I was kind of dreading this. But Dave did
• 3:07
  Speaker 1: a great job with this article, sort of like you
• 3:09
  Speaker 1: here in the traditional sense, like you said, yep, And
• 3:12
  Speaker 1: he does a good job initially by sort of laying
• 3:15
  Speaker 1: the groundwork of regular light compared to a laser light.
• 3:18
  Speaker 1: And I think that's a great way to start.
• 3:21
  Speaker 2: Well, yeah, if we're going to talk about lasers, we
• 3:23
  Speaker 2: really I mean, we're talking about light. We kind of
• 3:25
  Speaker 2: need to go back a couple of steps and say, okay,
• 3:27
  Speaker 2: there's different kinds of light, you know, like the light
• 3:30
  Speaker 2: we think of as sunlight or a light bulb or
• 3:33
  Speaker 2: something like that, what we would call generally white light
• 3:37
  Speaker 2: is as a lot of people know, all of the
• 3:40
  Speaker 2: colors of the spectrum, the visible light spectrum together coming
• 3:43
  Speaker 2: together to form white light.
• 3:46
  Speaker 1: That's right, many different wavelengths. But just like you know,
• 3:50
  Speaker 1: elementary school science, when you get that prism and your
• 3:53
  Speaker 1: little mind is blown, it's still kind of blows my mind.
• 3:55
  Speaker 1: You scatter that light into its different wavelengths and it's
• 4:00
  Speaker 1: the colors of the rainbow there. But and this is
• 4:03
  Speaker 1: something that like I don't think I even realize this,
• 4:06
  Speaker 1: even those different wavelengths, it's not a single wavelengths. It's
• 4:09
  Speaker 1: still a spectrum of different wavelengths creating the red or
• 4:14
  Speaker 1: the blue or the yellow or whatever. And that's kind
• 4:16
  Speaker 1: of where we find ourselves, you know, departing in what
• 4:21
  Speaker 1: a laser ends at being.
• 4:24
  Speaker 2: Yeah, because so for example, the yellow band, what we
• 4:27
  Speaker 2: see is yellow, and the visible spectrum occupies the five
• 4:31
  Speaker 2: hundred and seventy nanimeter to five hundred and ninety nanimeter range.
• 4:35
  Speaker 2: You show up below that, I think you've got what
• 4:37
  Speaker 2: red orange, something like that. ROYGBIV, Yeah, I can't remember
• 4:42
  Speaker 2: above that you've got blue Green, roy g Green, and
• 4:46
  Speaker 2: those just have different wave links. They're all electromagnetic light.
• 4:51
  Speaker 2: It's the same thing as a microwave. It's the same
• 4:53
  Speaker 2: thing as a radio wave. It's the same thing as
• 4:54
  Speaker 2: a gamma ray. It's just the different frequencies make them
• 4:58
  Speaker 2: different kinds of energy what we call the visible spectrum.
• 5:04
  Speaker 2: The point is is within all those different nanometer wavelengths,
• 5:07
  Speaker 2: say from five to seventy to five ninety, there's different
• 5:10
  Speaker 2: kinds of yellow. There's different shades of yellow right in
• 5:13
  Speaker 2: there across that the spectrum within the spectrum, I guess.
• 5:16
  Speaker 1: Yeah, spectrum within the spectrum. Also a great album title.
• 5:21
  Speaker 2: That is a great album title, Jeszisch. Maybe you could
• 5:24
  Speaker 2: have like a prism with a beam of light coming
• 5:27
  Speaker 2: in and then a rainbow coming out the other side.
• 5:29
  Speaker 1: Yeah, this is nineteen sixties for sure.
• 5:31
  Speaker 2: Yeah, pyramid even is a prism.
• 5:34
  Speaker 1: Yeah. With Isaac Kay's's head floating above it.
• 5:38
  Speaker 2: I'm describing the Dark Side of the Moon album cover.
• 5:42
  Speaker 1: I know it's just kidding.
• 5:43
  Speaker 2: Okay, well you were really throwing me off, you were.
• 5:45
  Speaker 2: That was some meta joking right there.
• 5:47
  Speaker 1: I have a great pressing of Dark Side of the
• 5:49
  Speaker 1: Moon by the way you do. Yeah, you know, I
• 5:52
  Speaker 1: had a record press or a guy who does that
• 5:54
  Speaker 1: for a living. I was hanging out with him in
• 5:56
  Speaker 1: New York with our friend Joey Ciara and these two
• 5:58
  Speaker 1: guys who did that, and he said, yeah, some pressings
• 6:01
  Speaker 1: like it's done by a human, so you might have
• 6:03
  Speaker 1: some records that just sound really awesome because it was
• 6:06
  Speaker 1: well done. And I was like yeah, and they're you know,
• 6:08
  Speaker 1: one hundred and eighty gram. He was like, that's all bunk,
• 6:10
  Speaker 1: by the way. He's like, it just makes you feel
• 6:13
  Speaker 1: better that it's heavier, and I was like, oh man,
• 6:15
  Speaker 1: that's disappointing.
• 6:17
  Speaker 2: I do like the heft of a eighty gram.
• 6:19
  Speaker 1: Apparently, they said, is that's all just for you to
• 6:22
  Speaker 1: make you think it is better because it's heavier.
• 6:25
  Speaker 2: It's heavier, so it's worth more.
• 6:26
  Speaker 1: All right. So back to lasers. What you just described
• 6:30
  Speaker 1: very well, by the way, was regular light wavelength within
• 6:34
  Speaker 1: the wavelength. If you talk about the differences of a
• 6:37
  Speaker 1: laser light, you're talking about three main differences, in the
• 6:39
  Speaker 1: first of which is that single wavelength it's monoc like
• 6:43
  Speaker 1: truly monochromatic. That beam of light that a laser is
• 6:47
  Speaker 1: or I guess you know, produces Well, no, it's what
• 6:50
  Speaker 1: it is is is just a very it's a single wavelength,
• 6:54
  Speaker 1: highly highly concentrated.
• 6:56
  Speaker 2: Yeah, so rather than say a wavelength between five seventy
• 6:59
  Speaker 2: and five for being yellow, this is a five hundred
• 7:02
  Speaker 2: and seventy two nanometer wavelength that is that specific yellow.
• 7:06
  Speaker 2: That's right, and it's it's not it's made up entirely
• 7:10
  Speaker 2: of yellow light on the exact same wavelength. That is
• 7:14
  Speaker 2: incredibly important. That's a huge, huge difference. Lasers don't occur naturally.
• 7:19
  Speaker 2: We've figured out how to make them, and by we,
• 7:22
  Speaker 2: I'm including myself in you.
• 7:24
  Speaker 1: That's right. The second big difference between laser light and
• 7:28
  Speaker 1: regular light is that it's coherent. So not only is
• 7:32
  Speaker 1: it just a single wavelength, but the photons of the light,
• 7:35
  Speaker 1: and we're going to talk about where they come into
• 7:37
  Speaker 1: play here in a second. Thanks to mister Einstein or
• 7:39
  Speaker 1: doctor Einstein, the photons are perfectly in phase with one another.
• 7:43
  Speaker 1: So if you look at that wavelength, the peaks and
• 7:46
  Speaker 1: the troughs are all perfectly in sync.
• 7:49
  Speaker 2: Yeah, and not like they're following the same plane and
• 7:52
  Speaker 2: they're just kind of in synct like that like, they're
• 7:54
  Speaker 2: upright above each other, right below each other. They're not
• 7:56
  Speaker 2: interfering with one another in any way whatsoever.
• 8:00
  Speaker 1: That's right.
• 8:01
  Speaker 2: And then the last one is that they're colimated, meaning
• 8:04
  Speaker 2: they're all traveling in the exact same direction.
• 8:07
  Speaker 1: Yeah, I mean that's important. I mean culimated sort of
• 8:10
  Speaker 1: a fancy way of saying directional. But as we'll see,
• 8:14
  Speaker 1: they all have to be traveling that same direction to
• 8:16
  Speaker 1: pick up their little photon buddies.
• 8:18
  Speaker 2: Yeah. So essentially what you've got is a very specific
• 8:21
  Speaker 2: kind of the exact same kind of light, none of
• 8:24
  Speaker 2: which are interfering with the other photons that are coming
• 8:28
  Speaker 2: out of the laser, all of which are traveling in
• 8:30
  Speaker 2: the same direction, so they do not get in one
• 8:32
  Speaker 2: another's way, and they can be combined very very tightly.
• 8:36
  Speaker 2: And that's essentially what a laser does.
• 8:38
  Speaker 1: Yeah, for sure. And it all goes back to that
• 8:41
  Speaker 1: acronym stimulated emission, the SE and laser. You can't make
• 8:46
  Speaker 1: a laser without SE, that's true. You can't spell laser
• 8:50
  Speaker 1: without SE, and you can't have a laser without stimulated emission.
• 8:53
  Speaker 1: And our buddy Einstein is the guy who sort of
• 8:57
  Speaker 1: laid the theoretical groundwork. He didn't go out and build
• 8:59
  Speaker 1: a laser. That came later, but he laid the theoretical
• 9:02
  Speaker 1: groundwork for all of this back in the ridiculously in
• 9:06
  Speaker 1: the early nineteen hundreds.
• 9:08
  Speaker 2: Yeah, so back in nineteen oh five, most people were like,
• 9:12
  Speaker 2: light's a continuous wave, and by proxy, the universe is
• 9:16
  Speaker 2: one smooth, continuous thing. In Einstein's like, I don't think
• 9:19
  Speaker 2: that's true. I think if you zoom in far enough,
• 9:22
  Speaker 2: close enough into the fabric of the universe, you're going
• 9:24
  Speaker 2: to see it's actually made of discrete, little little things
• 9:28
  Speaker 2: and call them pixels, right, And he's like, if that's true,
• 9:33
  Speaker 2: then light can't be one continuous wave either. So I
• 9:37
  Speaker 2: think they're actually made up of those little tiny packets
• 9:40
  Speaker 2: that I'm going to call photons. And he turned out
• 9:43
  Speaker 2: to be right. He had a great equation for it too.
• 9:45
  Speaker 2: It's so elegantly simple. That's the thing about Einstein. He
• 9:49
  Speaker 2: could come up with like three different things and could
• 9:52
  Speaker 2: completely change our understanding of the universe.
• 9:54
  Speaker 1: Yeah, for sure, this is the Planck Einstein, Einstein, what
• 9:58
  Speaker 1: just happened? I was concentrating so heavily. I'm not saying Plank.
• 10:03
  Speaker 2: I've heard Plank I think that's how most people say.
• 10:05
  Speaker 1: Oh, I've always heard plank.
• 10:07
  Speaker 2: Okay, I've heard both, but most of the people I've
• 10:10
  Speaker 2: ever heard say plank. But I mean, I run in
• 10:12
  Speaker 2: pretty low brow crowds.
• 10:14
  Speaker 1: I think the probably the correctest plank, but most people
• 10:17
  Speaker 1: do say plank. You're right.
• 10:18
  Speaker 2: I like the way that you said it the first time.
• 10:20
  Speaker 2: The plank Einstein.
• 10:21
  Speaker 1: No, it says Einstein though. Yeah, the Plank Einstein relation,
• 10:28
  Speaker 1: which is the energy beach photon is equal to its
• 10:31
  Speaker 1: frequency times Plunk's constant e equals HF.
• 10:36
  Speaker 2: Yeah, and all Plunk's constant is all it is. It's
• 10:39
  Speaker 2: the smallest possible measurement of energy that anything can have
• 10:44
  Speaker 2: on like the quantum level. Right, And so Einstein was like, Hey,
• 10:49
  Speaker 2: I want to figure out how all this stuff kind
• 10:51
  Speaker 2: of interacts because I know that photons interact with electrons.
• 10:55
  Speaker 2: I'm just positive of it.
• 10:56
  Speaker 1: Wow.
• 10:57
  Speaker 2: And they were figured that's pretty good. They were figuring out.
• 11:01
  Speaker 2: He was figuring out I think other people were at
• 11:03
  Speaker 2: the same time that when you have sub atomic particles
• 11:07
  Speaker 2: like an electron orbiting an atom, which if you go
• 11:10
  Speaker 2: listen to our periodic Table episode, I think we did
• 11:13
  Speaker 2: a pretty decent explanation of how you know that symbolism
• 11:18
  Speaker 2: or that visualization of it is not very correct. But
• 11:22
  Speaker 2: for all intents and purposes for this, let's say that
• 11:25
  Speaker 2: these electrons orbit in different orbits around the atom, and
• 11:28
  Speaker 2: when a photon hits it that orbit, that electron goes
• 11:32
  Speaker 2: up in energy I think for like one hundred nanoseconds typically, Yeah,
• 11:37
  Speaker 2: and then it says, okay, I want to get back
• 11:39
  Speaker 2: to my resting state it's ground state, and it goes
• 11:41
  Speaker 2: back to its previous orbital But when it does, it
• 11:44
  Speaker 2: poops out a photon.
• 11:45
  Speaker 1: You know what's funny? What as earlier when I was
• 11:47
  Speaker 1: going over there in my head, I said, poops out
• 11:49
  Speaker 1: of photon.
• 11:50
  Speaker 2: Sure, I mean you and I we share a brain
• 11:53
  Speaker 2: when it comes to toilet humor.
• 11:55
  Speaker 1: Yeah, that's true. Yeah, that's exactly right. So an atom
• 11:58
  Speaker 1: is going to absorb that energy, and it can do
• 12:00
  Speaker 1: that in a lot of ways, but let's just say
• 12:02
  Speaker 1: in this case, it's like some it gets heated up,
• 12:04
  Speaker 1: you know, like literally heated up. Those electrons are going
• 12:08
  Speaker 1: to jump around and get excited. But once they that
• 12:10
  Speaker 1: makes it unstable. But it wants to be stable. So
• 12:12
  Speaker 1: when it goes back to that state. You're right, it
• 12:14
  Speaker 1: poops out that photon. Einstein saw this, called it spontaneous emission. Yeah,
• 12:22
  Speaker 1: and this happens all the time all over the place
• 12:25
  Speaker 1: in nature. These photons are getting pooped out all over
• 12:29
  Speaker 1: the place. But Einstein was like, well, hey, if it
• 12:31
  Speaker 1: happens all the time naturally, he theorized, maybe we can
• 12:35
  Speaker 1: we can stimulate it to do this. Maybe we can
• 12:37
  Speaker 1: make this happen and control that emission.
• 12:40
  Speaker 2: Yeah, Because here's the thing, right, Like you say you
• 12:43
  Speaker 2: have a photon that hits an atom and knocks an
• 12:46
  Speaker 2: electron into the higher energy state, then that electron poops
• 12:49
  Speaker 2: out a photon. Well, that electron is just absorbed the photon.
• 12:53
  Speaker 2: So another way of looking at it is the photon
• 12:55
  Speaker 2: essentially goes into the electron and comes back out the
• 12:59
  Speaker 2: other side kind of, but there's only one photon ever,
• 13:02
  Speaker 2: one gets absorbed, one's produced. What Einstein figured out is
• 13:06
  Speaker 2: with stimulated emission, you can use a photon to create
• 13:10
  Speaker 2: another photon without losing the first photon. And if you
• 13:13
  Speaker 2: do that a bunch of times, buddy, you can have like, oh,
• 13:17
  Speaker 2: like you could make a basket with your shirt and
• 13:19
  Speaker 2: fill it with photons.
• 13:20
  Speaker 1: If you do it, right, Yeah, I mean he realized
• 13:23
  Speaker 1: that photons like to hang out with one another, so
• 13:26
  Speaker 1: it doesn't take a lot to get them, you know,
• 13:30
  Speaker 1: traveling in a direction and saying, hey, buddy, come with me,
• 13:33
  Speaker 1: and it creates this sort of sort of like a snowball,
• 13:35
  Speaker 1: like a cascading effect where if you can get them
• 13:39
  Speaker 1: in an excited state and stimulate them and have them
• 13:44
  Speaker 1: pick up other photons and have them all travel in
• 13:46
  Speaker 1: the same direction, you're like halfway toward laser town pretty much.
• 13:53
  Speaker 2: You can see the outskirts of town and the light
• 13:55
  Speaker 2: shooting up in the sky.
• 13:56
  Speaker 1: Yeah you can.
• 13:58
  Speaker 2: So yeah, So that's stimulated emission. And the key here
• 14:02
  Speaker 2: is you don't have to spend a photon to get
• 14:04
  Speaker 2: a photon, right, You can excite the atom in other
• 14:08
  Speaker 2: ways as long as it's already in its excited state.
• 14:11
  Speaker 2: When the photon comes along, it's going to produce another photon. Now,
• 14:14
  Speaker 2: for the purposes of lasers, what's really really important here
• 14:18
  Speaker 2: is it is going to produce an exactly identical photon
• 14:21
  Speaker 2: as the first one that passes by, right, traveling in
• 14:26
  Speaker 2: the same direction, and it's not going to interfere with
• 14:29
  Speaker 2: the first one. So they're cohesive, and they're collimated, and
• 14:33
  Speaker 2: they're exactly the same. They're monochromatic, which, as we said before,
• 14:36
  Speaker 2: those are the things you need for a laser. So
• 14:39
  Speaker 2: Einstein figured out back in nineteen seventeen how to make
• 14:43
  Speaker 2: a laser, and it was like, you, guys, figure it out.
• 14:45
  Speaker 2: I'm going to think about some other stuff.
• 14:47
  Speaker 1: Yeah. And if you say, well, wait a minute, I
• 14:49
  Speaker 1: thought you said nineteen oh five, like it even took
• 14:52
  Speaker 1: Ein Einstein a little while to get there, you know,
• 14:54
  Speaker 1: that's right, took a little while. So should we take
• 14:56
  Speaker 1: a break.
• 14:58
  Speaker 2: Yeah, I feel like a break is imminent.
• 15:00
  Speaker 1: We'll be right back with more lasers, all right. So
• 15:24
  Speaker 1: when we left, Einstein did some great work kind of
• 15:28
  Speaker 1: laying the groundwork, this theoretical foundation of a laser. And
• 15:32
  Speaker 1: then he was like, guys, I like to think of
• 15:35
  Speaker 1: things with my brain and say them out loud and
• 15:37
  Speaker 1: write them on chalkboards. If you want to build this thing, fine,
• 15:41
  Speaker 1: maybe slide me some cash. But I don't do that
• 15:45
  Speaker 1: kind of work. So people did though, that followed in
• 15:48
  Speaker 1: his footsteps, and in the nineteenth fifties it was a
• 15:50
  Speaker 1: physicist named Charles Towns. He worked at Bell Labs and
• 15:55
  Speaker 1: he was doing research on microwaves microwave radiation, and he
• 16:00
  Speaker 1: was trying to He didn't know it yet, but he was.
• 16:04
  Speaker 1: He was halfway to laser town because he was trying
• 16:06
  Speaker 1: to find ways to concentrate a beam of microwaves.
• 16:10
  Speaker 2: In this case, what's nuts is this guy figured it out.
• 16:14
  Speaker 2: He just basically tinkered around and made his own version
• 16:17
  Speaker 2: of a laser. But rather than using light, he used
• 16:20
  Speaker 2: microwave beams. Right.
• 16:22
  Speaker 1: Yeah, he built like a thing.
• 16:24
  Speaker 2: Yeah, he just he used ammonia adams. He put him
• 16:27
  Speaker 2: in a sealed chamber and he got them to essentially
• 16:31
  Speaker 2: emit microwave radiation that he was able to concentrate into
• 16:36
  Speaker 2: a beam. Right, So that cascading effect happened just like
• 16:40
  Speaker 2: we discussed before, and essentially the only difference is it
• 16:44
  Speaker 2: wasn't a light, it was a microwave beam. And to
• 16:47
  Speaker 2: test it, he aimed it at the front pocket of
• 16:52
  Speaker 2: a passing colleague, Percy Spencer, who happened to have a
• 16:55
  Speaker 2: chocolate bar in the front pocket, and he melted it and
• 16:59
  Speaker 2: Percy Spencer never forgave him because that was his favorite
• 17:02
  Speaker 2: short sleeve, button down shirt.
• 17:04
  Speaker 1: I think we talked about this, did we do one
• 17:06
  Speaker 1: of microwaves. Yeah, okay, well that would be exactly where
• 17:09
  Speaker 1: we talked about it then, probably.
• 17:10
  Speaker 2: Yeah, and they weren't colleagues. I just made that part up.
• 17:13
  Speaker 2: But that was a that was for you, buddy.
• 17:15
  Speaker 1: Oh no, wait, there was a chocolate thing though, what right?
• 17:18
  Speaker 2: Yeah, yeah, yeah, that happened. But separately, I think Spencer
• 17:21
  Speaker 2: was in the presence of some microwave generator and his
• 17:24
  Speaker 2: chocolate bar melted. And now that went on to invent microwaves.
• 17:27
  Speaker 2: This thing was totally different. It's just yeah, it just
• 17:30
  Speaker 2: brought Percy Spencer to mind.
• 17:31
  Speaker 1: Yeah, I like it. So he literally called this a mazer,
• 17:37
  Speaker 1: a microwave amplified stimulated emission of radiation. He teamed up
• 17:42
  Speaker 1: with a guy. It was a colleague named Arthur Shallow,
• 17:45
  Speaker 1: and he said, let me see if we can do
• 17:47
  Speaker 1: the same thing with light, and we'll call it an
• 17:50
  Speaker 1: optical maser. And everyone was like, buddy, it's right there
• 17:54
  Speaker 1: in front of your face, like, come on, just get there.
• 17:59
  Speaker 2: I think it was theor myman I like to call
• 18:02
  Speaker 2: him my man who actually came up with the laser.
• 18:07
  Speaker 2: He built the first functional laser in nineteen.
• 18:11
  Speaker 1: Sixty and came up with a name.
• 18:13
  Speaker 2: I think he did Okay. Up to this point, they
• 18:17
  Speaker 2: were all theoretical and my man was the first one
• 18:21
  Speaker 2: to actually build one, and he used a ruby crystal,
• 18:25
  Speaker 2: which at the time I think had already been dismissed.
• 18:28
  Speaker 2: People were like, you can't use that to make a laser.
• 18:31
  Speaker 2: And he's like, let me try again, and he did
• 18:33
  Speaker 2: some more calculations. He's like, the ruby's actually going to
• 18:35
  Speaker 2: be great. So he used a pink ruby crystal as
• 18:39
  Speaker 2: what's called the gain medium.
• 18:41
  Speaker 1: Yeah, that's like the material lasing material that you would
• 18:44
  Speaker 1: use exactly.
• 18:45
  Speaker 2: That's where the atoms that you get excited are all stored.
• 18:48
  Speaker 1: Yeah, So he surrounded that crystal with a with a flash.
• 18:53
  Speaker 1: It was a coil shaped flash bulb. So that's that's
• 18:56
  Speaker 1: going to be the thing that you know, the heat
• 18:58
  Speaker 1: or whatever or the light that stimulates the initial reactions
• 19:02
  Speaker 1: the pump. Sure, and then the two ends of that
• 19:06
  Speaker 1: crystal were painted reflective silver. So everything is sort of
• 19:10
  Speaker 1: kind of trapped in there together, encouraging all those photons
• 19:13
  Speaker 1: to bounce around and get a little wild and create
• 19:16
  Speaker 1: more photons and say, hey, you know we're doing something here,
• 19:19
  Speaker 1: guys and all.
• 19:20
  Speaker 2: Yeah, all of these photons came out at six hundred
• 19:22
  Speaker 2: and ninety four nanometers, which I guess is the precise
• 19:25
  Speaker 2: wavelength of ruby red.
• 19:26
  Speaker 1: Yeah, I guess so.
• 19:28
  Speaker 2: And he showed that like there, there, here's a laser.
• 19:30
  Speaker 2: Check it out. Let me see your face. Basically, I
• 19:33
  Speaker 2: think was how he showed it off right. He would
• 19:36
  Speaker 2: just wave it in people's faces.
• 19:37
  Speaker 1: That's why he's my man.
• 19:40
  Speaker 2: So that was it. I mean, that was the first
• 19:43
  Speaker 2: laser that and it was what you want to say,
• 19:46
  Speaker 2: like it was as easy as that. Of course that's
• 19:48
  Speaker 2: not easy, but the principle of it is kind of
• 19:52
  Speaker 2: like you said, it's simple to understand, which is great.
• 19:55
  Speaker 2: Like we did one on the breathalyzer, and it is
• 19:58
  Speaker 2: so ridiculously complicated. It's more complicated than a laser by far.
• 20:03
  Speaker 1: I hated that one.
• 20:05
  Speaker 2: I did too.
• 20:05
  Speaker 1: That was a long period of time ago.
• 20:07
  Speaker 2: I remember we picked it, we started researching, and I
• 20:09
  Speaker 2: was like.
• 20:10
  Speaker 1: This sucks.
• 20:10
  Speaker 2: Wait, why am I not understanding this? It was just
• 20:13
  Speaker 2: so complex. Let's never talk about it again.
• 20:16
  Speaker 1: I think we just wanted the explanation to be like
• 20:18
  Speaker 1: blow into tube smells beer exactly.
• 20:22
  Speaker 2: You just make a bunch of like drunk jokes.
• 20:24
  Speaker 1: Exactly, all right, So that that was the first laser,
• 20:28
  Speaker 1: Like you said, he use that ruby to begin with.
• 20:31
  Speaker 1: But there are all sorts of gain mediums. There can
• 20:33
  Speaker 1: be liquids, there can be gases, and we should probably
• 20:37
  Speaker 1: go over the five main types of laser now, starting
• 20:41
  Speaker 1: with like if you've ever been for tattoo removal or
• 20:45
  Speaker 1: like had a skin cancer with laser removal, they're using
• 20:48
  Speaker 1: a solid state laser in that case, and it's called
• 20:51
  Speaker 1: solid state because they're using a solid crystal or a
• 20:55
  Speaker 1: glass or something like that. Mix it up with a
• 20:57
  Speaker 1: little with a gain medium like well, it's they're all
• 21:02
  Speaker 1: rare earth elements like chromium or something like that. Neodymium
• 21:07
  Speaker 1: is that one.
• 21:09
  Speaker 2: Yeah, there's also a bitterum you abitterum man I even
• 21:14
  Speaker 2: looked it up, udbium atbium.
• 21:17
  Speaker 1: Aterbium I betze, right, that's a that's why that looks funny.
• 21:20
  Speaker 2: It is great though, why t t E r b
• 21:23
  Speaker 2: I U m yatterbium I got it And all of
• 21:26
  Speaker 2: those Basically they dope that say, like you could still
• 21:29
  Speaker 2: use ruby, but you would create like a ruby crystal
• 21:32
  Speaker 2: that's doped with these impurities that you've selected based on
• 21:37
  Speaker 2: their say like reflective properties, or they're phosphorescent properties. These
• 21:42
  Speaker 2: things can generate some photons really efficiently, and they're going
• 21:46
  Speaker 2: to generate them in exactly the wavelength that you want. Yeah,
• 21:50
  Speaker 2: it's a solid state laser. I follows in the tradition
• 21:52
  Speaker 2: of that original Mamayan's laser from nineteen sixty.
• 21:55
  Speaker 1: You know, Emily knows not much about football, doesn't care,
• 21:58
  Speaker 1: but there's always a few plays that she knows of,
• 22:01
  Speaker 1: and it's always very funny. Patrick Mahomes is one of them,
• 22:06
  Speaker 1: and every time she'd hears of him or anything, she
• 22:09
  Speaker 1: just goes my homes very nice, sort of like my man.
• 22:13
  Speaker 2: Oh no, I'm with you. That's a great way to
• 22:15
  Speaker 2: say it. Nice.
• 22:17
  Speaker 1: One thing I wanted to point out though about these
• 22:18
  Speaker 1: different types of blazers is all of them are that
• 22:22
  Speaker 1: they use different types of blazers according to whatever application
• 22:25
  Speaker 1: they want to use it for. So it's not just like, hey,
• 22:28
  Speaker 1: these are cool, let's use let's use this crystal with
• 22:32
  Speaker 1: this doping agent because we just think it sounds awesome.
• 22:36
  Speaker 1: It's all highly specific to what you want to end
• 22:38
  Speaker 1: up using it for.
• 22:39
  Speaker 2: Yeah, Like even like tattoo removal you said, which I'm
• 22:42
  Speaker 2: in the process of I'm getting towards the end there, buddy.
• 22:45
  Speaker 1: How's it looking pretty gone?
• 22:47
  Speaker 2: Pretty light? Yeah? It start? Yeah, I mean you can
• 22:49
  Speaker 2: still see it, especially if you walk up to it,
• 22:51
  Speaker 2: but you could also miss it if you weren't looking
• 22:53
  Speaker 2: for it's getting like that, Just like while that guy's
• 22:56
  Speaker 2: got mildew on his arm.
• 22:58
  Speaker 1: I took the other tack. As you have seen recently
• 23:00
  Speaker 1: when we were on tour, I had a probably two
• 23:02
  Speaker 1: inch by two inch tattoo that I covered with half
• 23:04
  Speaker 1: of an arm sleeve.
• 23:07
  Speaker 2: I didn't see it. You haven't shown it to me? Oh?
• 23:09
  Speaker 1: How was was I always in long sleeves?
• 23:11
  Speaker 2: Yeah? And I forgot to ask. I actually thought about
• 23:14
  Speaker 2: that when we were researching this. I was like, I
• 23:16
  Speaker 2: haven't seen chucks do tattoo.
• 23:17
  Speaker 1: Well, i'll I'll take my shirt off in front of
• 23:19
  Speaker 1: you soon.
• 23:20
  Speaker 2: Okay. But even with the tattoo removal ones. They have
• 23:24
  Speaker 2: different types of solid state lasers. The gain medium is different. Right.
• 23:31
  Speaker 2: There's one called the n d YAG laser. Yeah, that's
• 23:37
  Speaker 2: a really common one. Neodymium doped yetrium. Yeah, aluminum garnet.
• 23:43
  Speaker 2: That's the gain medium. And that's for I don't remember
• 23:48
  Speaker 2: what that one's for I think different color like regular
• 23:51
  Speaker 2: color tattoos, whereas like if it's green, to use a
• 23:54
  Speaker 2: different kind of in gain medium.
• 23:56
  Speaker 1: Yeah.
• 23:56
  Speaker 2: Yeah, so it is extremely specific.
• 23:59
  Speaker 1: All right, well, can we move on to gas lasers.
• 24:02
  Speaker 2: I think it's time. Yeah.
• 24:03
  Speaker 1: So obviously they're going to use gases or gain medium.
• 24:06
  Speaker 1: It could be a carbon dioxide laser, it could be argne,
• 24:09
  Speaker 1: could be crypton if you're really into comic books. And
• 24:14
  Speaker 1: these are different than solid state layers. Obviously, in solid
• 24:18
  Speaker 1: state the atoms are excited by a light source. In
• 24:21
  Speaker 1: this case, it's an electrical current, and it's going to
• 24:23
  Speaker 1: get them going.
• 24:25
  Speaker 2: Yeah, it gets them excited. There's all sorts of stuff
• 24:29
  Speaker 2: you can use with gas lasers, but probably one of
• 24:31
  Speaker 2: the most famous one is using a carbon dioxide as
• 24:34
  Speaker 2: the gain medium, and those things can get those photons going.
• 24:39
  Speaker 2: You can weld with it. That's how powerful these lasers can.
• 24:45
  Speaker 2: You can weld metal with that stuff. And then at
• 24:47
  Speaker 2: the same time, if you use a different gas, you
• 24:51
  Speaker 2: might have a eximer laser. You can actually break the
• 24:54
  Speaker 2: bonds that hold molecules together. You can alter cells, you
• 24:57
  Speaker 2: can destroy tissue. But it uses UV lights, so it
• 25:01
  Speaker 2: doesn't produce heat. So that's how you can use that
• 25:04
  Speaker 2: on someone's skin without burning them, but still say removing
• 25:07
  Speaker 2: like a squamous cell or something.
• 25:10
  Speaker 1: Yeah, or if you've ever heard of something being laser cut,
• 25:14
  Speaker 1: then it's probably going to be a gas laser doing
• 25:16
  Speaker 1: that business.
• 25:17
  Speaker 2: Yeah, hopefully that you didn't hear about that from a
• 25:19
  Speaker 2: squama cell being removed.
• 25:21
  Speaker 1: Right.
• 25:22
  Speaker 2: There's also fiber lasers. These are very special lasers. I
• 25:27
  Speaker 2: don't know how they found this out, but scientists concluded
• 25:30
  Speaker 2: that the cloaks usually or the textiles found with bog bodies,
• 25:36
  Speaker 2: have some sort of magical properties that if you use
• 25:38
  Speaker 2: them as a gain medium, they make really great lasers.
• 25:42
  Speaker 2: Hence fiber lasers.
• 25:43
  Speaker 1: Right, But in this case they're used in conjunction with
• 25:47
  Speaker 1: a fiber optic cable. And so these are obviously have
• 25:50
  Speaker 1: long been used in telecommunications and stuff like that. And
• 25:54
  Speaker 1: because they are used in conjunction with an actual cable,
• 25:58
  Speaker 1: they're very very efficient. Convert more than fifty percent of
• 26:02
  Speaker 1: the electricity that's input into light. But that d YAG
• 26:09
  Speaker 1: laser has about a three percent efficiency rate.
• 26:12
  Speaker 2: Yeah, that's pretty efficient. That's another way that lasers are
• 26:16
  Speaker 2: part of your everyday life. If you have fiber Internet,
• 26:21
  Speaker 2: like you have a laser on one end that your
• 26:24
  Speaker 2: ISP is using to send communications or encoded information along
• 26:31
  Speaker 2: a fiber optic cable, and your modem is basically a
• 26:33
  Speaker 2: laser receiver that translates it into whatever your router needs
• 26:37
  Speaker 2: to explain it to you.
• 26:39
  Speaker 1: Yeah, that man, that breaks my brain like vinyl records,
• 26:43
  Speaker 1: does you know?
• 26:44
  Speaker 2: Yeah? It's pretty cool though, And that's the thing. So
• 26:47
  Speaker 2: it's just like when radio with radio waves, we figured
• 26:51
  Speaker 2: out how to encode information, and radio waves we figured
• 26:54
  Speaker 2: out how to do that with light. It's just lasers
• 26:56
  Speaker 2: are way more efficient. They can travel way longer than
• 27:00
  Speaker 2: radio waves can. And apparently they're starting to look into
• 27:03
  Speaker 2: this to transmit information between the Earth and the Moon. Well, boy,
• 27:09
  Speaker 2: so you'll just be able to you'll have basically not
• 27:12
  Speaker 2: even fiber optic Internet, you'll have laser Internet on the moon.
• 27:17
  Speaker 1: Wow.
• 27:18
  Speaker 2: I thought. I think that's wow too. Yeah, what about
• 27:21
  Speaker 2: liquid lasers or die lasers? I should probably say, because
• 27:24
  Speaker 2: you played that so straight, my explanation of what the
• 27:27
  Speaker 2: gain medium is for fiber lasers that I just made
• 27:30
  Speaker 2: that up.
• 27:30
  Speaker 1: Everybody, Oh, I fall victim again.
• 27:36
  Speaker 2: Did you thought that they used the cloaks from bog
• 27:39
  Speaker 2: bodies for that.
• 27:41
  Speaker 1: Man, I don't all of this stuff is so brain breaking.
• 27:43
  Speaker 1: Nothing nothing. Would You could say human feces and I'd
• 27:45
  Speaker 1: be like, yeah, of.
• 27:46
  Speaker 2: Course that'd be man, that'd be gross. But I'll bet
• 27:49
  Speaker 2: you could. I think you could use anything with atoms
• 27:52
  Speaker 2: that's excitable to potentially make a laser.
• 27:55
  Speaker 1: You've become such a good straight person that it's just
• 27:58
  Speaker 1: hard to tell anymore.
• 27:59
  Speaker 2: It's hard to tell with you too, Hey, thanks, Yeah,
• 28:02
  Speaker 2: thank you. Uh.
• 28:03
  Speaker 1: Liquid lasers or dye lasers, these are sort of brain
• 28:06
  Speaker 1: breaking to these organic dyes as the gain medium, which
• 28:10
  Speaker 1: is kind of crazy to think about. But each die,
• 28:12
  Speaker 1: like uh, will produce a different laser light because they're
• 28:15
  Speaker 1: going to have, you know, because it's a color, like
• 28:16
  Speaker 1: a different wavelength.
• 28:18
  Speaker 2: Right.
• 28:18
  Speaker 1: And these are really cool because you can actually tune
• 28:20
  Speaker 1: them to a very you can manipulate them and tune
• 28:23
  Speaker 1: them within a very specific range for specific uses.
• 28:27
  Speaker 2: Yeah. So one laser can be used for all sorts
• 28:30
  Speaker 2: of different things, which is I'm sure quite cost efficient.
• 28:33
  Speaker 1: Yeah.
• 28:34
  Speaker 2: I think that's one of the downsides of solid state lasers.
• 28:36
  Speaker 2: It's like one thing you can be with one laser.
• 28:39
  Speaker 1: Yeah, Although That.
• 28:40
  Speaker 2: Would be cool if like it's just a cartridge you
• 28:42
  Speaker 2: can pop out and put in a new a new crystal. Yeah,
• 28:45
  Speaker 2: that'd be sweet.
• 28:46
  Speaker 1: They should work on that.
• 28:48
  Speaker 2: They have to be, you know, like the cost of
• 28:50
  Speaker 2: lasers have come down tremendously. I'm sure we'll eventually get there.
• 28:55
  Speaker 1: Yeah, just ask my cat, my cats with an us.
• 28:59
  Speaker 2: Well, let's talk about but that. We're kind of at
• 29:01
  Speaker 2: that point. Do you play with your cats with laser pointers? No?
• 29:05
  Speaker 1: I have, but they always get lost because they're always small.
• 29:09
  Speaker 2: Oh gotcha? Gotcha? Well that is actually a kind of laser.
• 29:13
  Speaker 2: That's why they call them laser pointers. They're the weakest laser.
• 29:16
  Speaker 1: Yeah.
• 29:17
  Speaker 2: But they use diodes, which are two different materials that
• 29:20
  Speaker 2: when you put them together with a place where they interface,
• 29:23
  Speaker 2: creates an electron exchange and hence a flow of electrons
• 29:27
  Speaker 2: and that creates electricity. So that's what these things are
• 29:30
  Speaker 2: powered by. This is the way that the light. Photons
• 29:34
  Speaker 2: get made from the excited atoms, and they're super cheap.
• 29:38
  Speaker 2: They're not very powerful, and that means that over a
• 29:41
  Speaker 2: fairly short distance I think like hundreds of meters, they
• 29:45
  Speaker 2: basically they're not a tiny point any longer Yeah, And
• 29:48
  Speaker 2: I was looking into this because when I hear laser pointers,
• 29:51
  Speaker 2: I think of jerks like trying to shine in the
• 29:53
  Speaker 2: light of an airline pilot.
• 29:55
  Speaker 1: Oh.
• 29:55
  Speaker 2: Sure, that's a real problem. Actually, I think it happens
• 29:58
  Speaker 2: a couple thousand times a year in the US alone.
• 30:00
  Speaker 1: Yeah, concerts too, people do that stuff.
• 30:02
  Speaker 2: Sure. The reason you're not supposed to do that with
• 30:05
  Speaker 2: airline pilots is because by the time it reaches the cockpit,
• 30:08
  Speaker 2: it has spread out so much that it's so man
• 30:11
  Speaker 2: it's like a huge ball of light. Yeah, that is
• 30:14
  Speaker 2: so bright in the cockpit that they can't even see
• 30:16
  Speaker 2: the instruments anymore.
• 30:17
  Speaker 1: Yeah.
• 30:18
  Speaker 2: So it's not like you're just putting like a little
• 30:20
  Speaker 2: dot on somebody's cheek. You are blinding everybody in the cockpit. Right.
• 30:24
  Speaker 2: Then it's a huge problem that you really should not do.
• 30:27
  Speaker 1: Yeah. And also, what's funny about messing with someone doing
• 30:31
  Speaker 1: a very important, dangerous job where hundreds and hundreds of
• 30:34
  Speaker 1: lives are at stake. Yeah, let's mess with that person.
• 30:37
  Speaker 2: Yes, and I think everyone's parents should sit them down
• 30:40
  Speaker 2: and say, yeah, let's talk about laser pointers, because you
• 30:43
  Speaker 2: probably aren't grasping what a problem this is.
• 30:46
  Speaker 1: Agreed. Well, that's a weak one. Those diode lasers are
• 30:50
  Speaker 1: semiconductor lasers. But since the very beginning, science has tried
• 30:55
  Speaker 1: to make the more powerful lasers and they have a
• 31:00
  Speaker 1: pretty great job at it. We'll go over some of these.
• 31:02
  Speaker 1: But you measure in a laser by how quickly that
• 31:06
  Speaker 1: laser is emitting the energy, so it's jewels of energy
• 31:10
  Speaker 1: emitted per second. They measure that in watts, and they
• 31:15
  Speaker 1: figured out pretty early on that a continuous beam of
• 31:18
  Speaker 1: light emits a constant amount of energy over time. So
• 31:22
  Speaker 1: they were like, hey, I bet we can make these
• 31:24
  Speaker 1: even more powerful if we cut that off very quickly,
• 31:28
  Speaker 1: over and over and over and admit pulses of energy
• 31:31
  Speaker 1: because it builds up and it just gets stronger and stronger.
• 31:34
  Speaker 1: And they tried it out and it really worked.
• 31:37
  Speaker 2: Yeah, pulse lasers right, because, like you said, a traditional laser,
• 31:40
  Speaker 2: it's the same amount of energy the whole time the
• 31:42
  Speaker 2: beam is on the pulse laser, it's kind of like
• 31:45
  Speaker 2: stopping up the uh, the beam of light, so that
• 31:49
  Speaker 2: it just the energy builds up behind it and then
• 31:51
  Speaker 2: you open it up again and when you release it,
• 31:53
  Speaker 2: it's this ultra concentrated beam of energy, and it's it's
• 31:59
  Speaker 2: mind by uggling. How fast this happens so fast that
• 32:03
  Speaker 2: your puny brain just sees it as one constant beam
• 32:06
  Speaker 2: of light. Yeah, we don't have the technology to slow
• 32:09
  Speaker 2: it down enough. I don't think to see the pulsing
• 32:12
  Speaker 2: because we're talking billions, trillions, quadrillions, quintillions of a second.
• 32:17
  Speaker 2: How frequently those the thing is pulsing.
• 32:21
  Speaker 1: Yeah, it's incredible. I think they first demonstrated that in
• 32:24
  Speaker 1: nineteen sixty one with that Ruby laser, and I think
• 32:29
  Speaker 1: they ended up with one hundred nanosecond burst in nineteen
• 32:32
  Speaker 1: sixty one, which is pretty impressive.
• 32:33
  Speaker 2: Yeah, for sure, because a nanosecond is a billionth of
• 32:36
  Speaker 2: a second.
• 32:37
  Speaker 1: Yeah, so in nineteen sixty one they were able to
• 32:39
  Speaker 1: get that first laser by pulsing it up to one
• 32:42
  Speaker 1: thousand times more powerful than my man's device.
• 32:46
  Speaker 2: Yeah. This was a year after he built that first laser, right, Yeah,
• 32:51
  Speaker 2: So I think that was when you say one hundred
• 32:53
  Speaker 2: nanosecond bursts. I saw that. With the tech that they're
• 32:56
  Speaker 2: using now, nanosecond pulses are called giant pulses. Yeah, seriously,
• 33:02
  Speaker 2: that's what they consider them.
• 33:03
  Speaker 1: Yeah, and those are quintillions of a second, which is
• 33:06
  Speaker 1: hard to even wrap your head around for sure.
• 33:08
  Speaker 2: Right, So these things, these pulses are just like that's
• 33:11
  Speaker 2: it also, Chuck, I think goes to show you how
• 33:14
  Speaker 2: quickly energy builds up in the chamber that where the
• 33:18
  Speaker 2: beam is released from that it's it's like creating a
• 33:21
  Speaker 2: thousand times or ten thousand times or however many times
• 33:24
  Speaker 2: stronger beam just from backing it up in like one
• 33:29
  Speaker 2: quintillionth of a second. Yeah, sure, you want to take
• 33:35
  Speaker 2: a break.
• 33:36
  Speaker 1: Yeah, let's take a break, and let's talk about just
• 33:38
  Speaker 1: sort of real world uses and what's going on out there.
• 33:40
  Speaker 2: Okay, So, Chuck, there's some there's some lasers that are
• 34:05
  Speaker 2: just super powerful that are being built right now. Of course,
• 34:08
  Speaker 2: physicists are like, let's see how powerful we can make something.
• 34:11
  Speaker 2: There's one at the University of Michigan called zeus Zetiwa
• 34:15
  Speaker 2: Equivalent Ultra Short Pulse Laser System. And then there's one
• 34:19
  Speaker 2: in the UK that's being built called the Vulcan Laser.
• 34:23
  Speaker 1: Yeah, and these, I mean, the one in the UK
• 34:26
  Speaker 1: has a power of five hundred million forty what light bulbs,
• 34:31
  Speaker 1: well forty well, yeah, that's true, that's not much. And
• 34:35
  Speaker 1: the Zeus can generate a pulse of light that's twenty
• 34:39
  Speaker 1: five quintillions of a second long.
• 34:42
  Speaker 2: And so but wait, how much energy does it release?
• 34:46
  Speaker 1: Three petawats baby, which is one hundred times the total
• 34:50
  Speaker 1: electrical output of the entire world in one quick burst.
• 34:56
  Speaker 2: So these things are they're like, they're so powerful and
• 35:01
  Speaker 2: energetic that they're one of the main things they're going
• 35:04
  Speaker 2: to be used for is to study what it's like
• 35:07
  Speaker 2: inside a black hole or a star or something like that.
• 35:10
  Speaker 2: That's that's like what they're able to recreate and see
• 35:12
  Speaker 2: what happens when it bounces off of an apple or
• 35:15
  Speaker 2: something like that. What happens when you bounce a black
• 35:18
  Speaker 2: hole off of an apple?
• 35:19
  Speaker 1: Yeah, that's that's basically why they're trying to create these
• 35:23
  Speaker 1: this powerful. It's not so they can blow up the
• 35:25
  Speaker 1: Death Star, even though that's a good case use. It's so, yeah,
• 35:30
  Speaker 1: so they can recreate like the energy and the inside
• 35:34
  Speaker 1: of a star and find out the mysteries of the
• 35:36
  Speaker 1: universe basically exactly.
• 35:38
  Speaker 2: There's another thing you can use really really powerful lasers for,
• 35:41
  Speaker 2: and that's nuclear fusion. And we did a whole episode
• 35:44
  Speaker 2: on nuclear fusion, I think in twenty nineteen that was
• 35:48
  Speaker 2: one of my favorites of all time, and it's this
• 35:51
  Speaker 2: whole thing that's the promise of basically free, unlimited energy
• 35:56
  Speaker 2: that you can power anything with with almost like what
• 35:59
  Speaker 2: you're getting out is way more than what you're putting in.
• 36:03
  Speaker 2: And it's essentially where you take light nuclei and fuse
• 36:07
  Speaker 2: them together to create a heavy nuclei and a lot
• 36:10
  Speaker 2: of energy is released. It's just we haven't quite figured
• 36:13
  Speaker 2: it out. Well. You need like plasma concentrations. These are
• 36:17
  Speaker 2: plasma lasers, and apparently in twenty twenty two at the
• 36:21
  Speaker 2: Lawrence Livermore Lab, they use one hundred and ninety two
• 36:24
  Speaker 2: of these lasers to essentially create the world's first nuclear
• 36:29
  Speaker 2: fusion reaction that produced more energy than was put in.
• 36:34
  Speaker 2: There was a net gain.
• 36:36
  Speaker 1: Yeah, they called that the Right Brothers moment as far
• 36:40
  Speaker 1: as lasers go, sure, because you got a net gain
• 36:42
  Speaker 1: for the first time. They focus those lasers at a
• 36:45
  Speaker 1: capsule the size of a peppercorn, and that did it.
• 36:48
  Speaker 1: And I bet that was a great day in that lab.
• 36:50
  Speaker 2: I'm sure. I mean, once we get to nuclear fusion,
• 36:53
  Speaker 2: that's that's going to change absolutely everything.
• 36:57
  Speaker 1: Yeah, for sure.
• 36:59
  Speaker 2: So you can use it for nuclear fusion. You can
• 37:02
  Speaker 2: use really great lasers to recreate different, crazy exotic aspects
• 37:08
  Speaker 2: of the universe. There's also way more pedestrian uses for lasers,
• 37:12
  Speaker 2: like we said barcodes, fiber optic communication. But they're like
• 37:17
  Speaker 2: when you're start to look around, lasers are everywhere. Essentially,
• 37:20
  Speaker 2: anything you can bounce light off of or that that
• 37:26
  Speaker 2: will absorb light you can use a laser for for
• 37:30
  Speaker 2: some application or other.
• 37:31
  Speaker 1: Yeah, for sure, they're all over the medical industry for
• 37:35
  Speaker 1: in all kinds of ways. I think pretty early on
• 37:38
  Speaker 1: they were like, hey, these using a laser to cut
• 37:41
  Speaker 1: into the human body is way better than a scalpel. Sure,
• 37:44
  Speaker 1: it's way more precise, there's less damage on the tissue
• 37:47
  Speaker 1: it self kind of self cauterizes as it goes, So
• 37:51
  Speaker 1: it's going to be sterilizing the tissue that surrounds it.
• 37:54
  Speaker 1: It's going to be less blood loss, you're going to
• 37:56
  Speaker 1: heal up quicker. So that's there. I mean, scalpels are
• 37:59
  Speaker 1: still around, but you know, lasers are the way to go.
• 38:01
  Speaker 2: I saw that there's a brain tumor laser procedure that
• 38:06
  Speaker 2: uses a five millimeter hole in the skull and you
• 38:09
  Speaker 2: get discharged the next day. That's how accurate and amazing
• 38:13
  Speaker 2: these things are. Plus also, it's way easier to attach
• 38:15
  Speaker 2: to a robot than to give a robot a scalpel
• 38:18
  Speaker 2: to use.
• 38:19
  Speaker 1: Yeah, I hate to bring it up again, but that
• 38:21
  Speaker 1: was just on an episode of The Pit, that exact.
• 38:24
  Speaker 2: Case use that you just mentioned, the laser tumor.
• 38:27
  Speaker 1: Yeah, the tiny hole in the skull.
• 38:29
  Speaker 2: We started watching it, I gave it another try, you
• 38:31
  Speaker 2: me and I did, and it's it is pretty good
• 38:34
  Speaker 2: and engrossing.
• 38:35
  Speaker 1: Yeah, engross it is. Yeah, and I figured out too
• 38:40
  Speaker 1: watching last night, I kind of forgot the reason why
• 38:43
  Speaker 1: I was saying. There's so much of like of Noah
• 38:45
  Speaker 1: Wiley over explaining everything to all the younger doctors and
• 38:49
  Speaker 1: residences because it's a teaching hospital.
• 38:51
  Speaker 2: Yeah, there you go, which is.
• 38:53
  Speaker 1: A great vehicle to explain whatever the heck is going
• 38:56
  Speaker 1: on to the viewer at home, you know, yep, for sure.
• 39:00
  Speaker 1: All right, So back to medicals, since we're talking about
• 39:03
  Speaker 1: the PIT. If you ever had an endoscope, that's you
• 39:06
  Speaker 1: know when they put a long flexible tube down your
• 39:09
  Speaker 1: throat a lot of times, or up your nose or
• 39:12
  Speaker 1: who knows what holes they can put them into these days, it.
• 39:14
  Speaker 2: Depends if it's a rubber hose, you know where that goes.
• 39:17
  Speaker 1: That's right, Vinny. Essentially you can access these tough to
• 39:22
  Speaker 1: reach areas with these tiny little tubes, and in this case,
• 39:25
  Speaker 1: you can have a laser attached to it and send
• 39:28
  Speaker 1: it in there to shrink a tumor like you were
• 39:30
  Speaker 1: talking about.
• 39:31
  Speaker 2: Right, And then you can also use them to do
• 39:34
  Speaker 2: things like destroy the epidermis and then heat up the
• 39:37
  Speaker 2: dermis underneath to get rid of like spots or something
• 39:40
  Speaker 2: like that. For all sorts of esthetic dermatological applications.
• 39:45
  Speaker 1: Yeah, cosmetic stuff.
• 39:46
  Speaker 2: YEP, tattoo removal, that kind of thing.
• 39:49
  Speaker 1: Laser, what about lask Yeah, Lasik.
• 39:51
  Speaker 2: Is a big one that has become vastly improved as
• 39:55
  Speaker 2: lasers and robots have improved. I think it was first
• 39:58
  Speaker 2: started at first became approved in the US and nineteen
• 40:02
  Speaker 2: ninety nine, and since then it's gotten really good. I
• 40:05
  Speaker 2: think ninety percent of people who get Lasik have between
• 40:09
  Speaker 2: twenty twenty and twenty forty vision afterward. And it's like
• 40:14
  Speaker 2: the pool of people who are candidates for it are
• 40:19
  Speaker 2: is pretty wide. It's not like, yeah, if you can
• 40:21
  Speaker 2: if you need just like those magnifying readers that you
• 40:23
  Speaker 2: buy at the pharmacy. You're gonna Lasik's gonna benefit. You know,
• 40:27
  Speaker 2: you can have like pretty bad myopia and still benefit
• 40:31
  Speaker 2: from it.
• 40:32
  Speaker 1: Yeah, in this case, they use the laser to reshape
• 40:35
  Speaker 1: the cornea. Didn't you debate laser at one point?
• 40:39
  Speaker 2: Yeah, I'm still thinking about it. But my vision we're
• 40:43
  Speaker 2: basically at an age where your vision changes fairly rapidly
• 40:47
  Speaker 2: and you want it to stabilize or else you'd get
• 40:50
  Speaker 2: lasik once and then you'd end up needing glasses when
• 40:53
  Speaker 2: your vision degrades again.
• 40:55
  Speaker 1: I think Emily has been debating it to a little
• 40:58
  Speaker 1: bit lately. I'm not sure why.
• 40:59
  Speaker 2: I look into it and I was convinced, like this
• 41:01
  Speaker 2: is this is pretty safe and effective, and yeah, yeah
• 41:04
  Speaker 2: I would do it. I'm just not there yet.
• 41:06
  Speaker 1: I feel like when I've seen you lately, you're having
• 41:08
  Speaker 1: trouble with a contact.
• 41:10
  Speaker 2: Lens because it's been wintertime and dry. Uh it makes
• 41:14
  Speaker 2: them like it makes it easier for it to like
• 41:16
  Speaker 2: fold over something like that. Popca sucks.
• 41:20
  Speaker 1: I'm sorry.
• 41:22
  Speaker 2: There's also weapons. Of course, you can use lasers for weapons.
• 41:25
  Speaker 2: Apparently the Army, the Navy, and the Air Force are
• 41:28
  Speaker 2: developing laser weapons to different different levels of success, but
• 41:34
  Speaker 2: they're definitely working on them, not to necessarily like you know,
• 41:37
  Speaker 2: mow doown troops, but to say, blow up a drone
• 41:41
  Speaker 2: or something like that.
• 41:42
  Speaker 1: Yeah, they're called directed energy systems. Some of them attached
• 41:47
  Speaker 1: to like a turret on a ship. Those seem to
• 41:52
  Speaker 1: work pretty well for like you said, like taking down
• 41:54
  Speaker 1: a drone or something like that.
• 41:55
  Speaker 2: Mm hmm.
• 41:56
  Speaker 1: They have others. I think the army has one fifth
• 42:00
  Speaker 1: to kill a WATT that's on an armored fighting vehicle,
• 42:02
  Speaker 1: but that hasn't done so well because you know, for
• 42:07
  Speaker 1: a laser weapon to be pretty effective, it has to
• 42:09
  Speaker 1: be super tightly focused and pretty locked down. And they're like, hey,
• 42:14
  Speaker 1: we're driving this thing around and it's not very accurate, right.
• 42:17
  Speaker 2: And that's the Striker armored fighting vehicle, Striker with a Y. Yeah,
• 42:22
  Speaker 2: it's like they look to G. I. Joe stuff to
• 42:24
  Speaker 2: come up with ms for it.
• 42:26
  Speaker 1: For sure.
• 42:27
  Speaker 2: There's also this one's pretty sweet too. It's laser cooling.
• 42:30
  Speaker 2: And there's also so many different applications, like you can
• 42:33
  Speaker 2: you can track soil moisture from space to see how
• 42:37
  Speaker 2: bad a route is. You can track how badly ice
• 42:41
  Speaker 2: is receding in the in the polar areas. You can
• 42:44
  Speaker 2: you can do everything with with lasers. They're really great
• 42:47
  Speaker 2: in case that hasn't gotten across so far, but this one,
• 42:50
  Speaker 2: to me is just amazingly cool.
• 42:55
  Speaker 1: Yeah, no pun intended laser cooling. What they're doing is
• 42:58
  Speaker 1: basically kind of freezing and at them or molecule in place.
• 43:03
  Speaker 1: It's also called a particle trap, and it's the same
• 43:07
  Speaker 1: sort of physics of stimulated emission, but kind of been reverse.
• 43:12
  Speaker 2: Yeah, when an atom poops out a photon that kind
• 43:18
  Speaker 2: of pushes it in the opposite direction that the photon's traveling.
• 43:21
  Speaker 2: They figured out that they can use lasers to keep
• 43:24
  Speaker 2: to basically balance that out. So these things are still
• 43:28
  Speaker 2: producing photons, they're still doing their thing. They're in energetic
• 43:32
  Speaker 2: states and oscillating and doing all sorts of stuff like
• 43:34
  Speaker 2: they're supposed to, but they're just not moving around in
• 43:37
  Speaker 2: space while they're doing it. Yeah, So they're essentially they're
• 43:41
  Speaker 2: just it's like a tractor beam holding it where you
• 43:45
  Speaker 2: want it.
• 43:46
  Speaker 1: Yeah, it just slows it down such that it's basically stopped.
• 43:50
  Speaker 2: Yeah, but it's still doing its thing. It's not moving
• 43:53
  Speaker 2: around while it's doing it right. So, now that you
• 43:55
  Speaker 2: have an atom trapped, you can do something like this
• 44:00
  Speaker 2: is the future of atomic clocks. You can measure the
• 44:03
  Speaker 2: oscillations oscillations of that one specific atom so precisely that
• 44:08
  Speaker 2: atomic clocks are about to be just ridiculously more reliable
• 44:13
  Speaker 2: than the atomic clocks today, which I think we can
• 44:16
  Speaker 2: all agree are pretty reliable. So that's a huge groundbreaking
• 44:19
  Speaker 2: use for that.
• 44:21
  Speaker 1: Yeah, for sure. I mean it's easier to study something
• 44:23
  Speaker 1: that's sitting still exactly. Yeah.
• 44:26
  Speaker 2: Yeah, now that I think about it, that basically overcomes
• 44:29
  Speaker 2: Heisenberg's uncertainty principle, where you can't measure something and know
• 44:33
  Speaker 2: where it is at the exact same time. Apparently Heisenberg
• 44:36
  Speaker 2: didn't think of lasers.
• 44:38
  Speaker 1: That's a nerdiest sentence you've ever said. Oh, come to
• 44:42
  Speaker 1: think of.
• 44:42
  Speaker 2: It, you got anything else?
• 44:45
  Speaker 1: I got nothing else that you know, there's obviously a
• 44:47
  Speaker 1: lot more about it. I think that was a good,
• 44:49
  Speaker 1: good old fashioned overview of lasers.
• 44:52
  Speaker 2: Great man, And since Chuck said old fashioned, he just
• 44:56
  Speaker 2: accidentally triggered listener mail.
• 45:00
  Speaker 1: I'm going to call this an answer to a question.
• 45:02
  Speaker 1: I love it when we put out a question we
• 45:04
  Speaker 1: get answered. We were talking about color psychology, and I
• 45:08
  Speaker 1: wondered because I have a African American church around the
• 45:11
  Speaker 1: corner from me.
• 45:12
  Speaker 2: Oh, yes, that purple.
• 45:13
  Speaker 1: Actually, yeah, purple, And we heard from a listener. Hey, guys,
• 45:17
  Speaker 1: I'm writing to share some insight regarding the morning colors
• 45:20
  Speaker 1: at the nearby church. While traditions can vary between African
• 45:23
  Speaker 1: American churches, I hope the following information is helpful. In
• 45:26
  Speaker 1: the twenty first century African American traditions, it is common
• 45:29
  Speaker 1: for individuals attending a funeral to where the deceased person's
• 45:32
  Speaker 1: favorite color, which is what I thought might be happening.
• 45:34
  Speaker 2: Oh.
• 45:35
  Speaker 1: In some cases, all and attendance are encouraged to do so,
• 45:37
  Speaker 1: while in others it's reserved for family members. Regarding the
• 45:41
  Speaker 1: use of purple, specifically, this color is typically associated with
• 45:45
  Speaker 1: royalty in Jesus Christ. If you consistently see purple at
• 45:48
  Speaker 1: the church, it may be it may signify recognition of
• 45:51
  Speaker 1: the deceased returning to God, or maybe just the person's
• 45:55
  Speaker 1: favorite color. So I truly appreciate your program allows me
• 45:58
  Speaker 1: to stay present and provides a welcome escape from the
• 46:01
  Speaker 1: daily news cycle. I look forward to becoming just a
• 46:04
  Speaker 1: tadbit smarter as I continue to be an enthusiastic listener. Corgially, Teresa,
• 46:09
  Speaker 1: what a lovely email.
• 46:10
  Speaker 2: That was a great email, Chorisa, thank you very much
• 46:13
  Speaker 2: for it, and now your mystery solved.
• 46:15
  Speaker 1: Chuck, that's right.
• 46:16
  Speaker 2: We love emails that solved mysteries that we were wondering about.
• 46:20
  Speaker 2: So if you've got a solution to one of our mysteries,
• 46:23
  Speaker 2: we would love to hear it. You can also write
• 46:25
  Speaker 2: in for any other reason. Just send your email to
• 46:28
  Speaker 2: stuff podcast at iHeartRadio dot com.
• 46:34
  Speaker 1: Stuff you Should Know is a production of iHeartRadio. For
• 46:37
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• 46:41
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