1 00:00:00,280 --> 00:00:02,840 Speaker 1: Brought to you by the reinvented two thousand twelve camera. 2 00:00:03,160 --> 00:00:08,920 Speaker 1: It's ready. Are you get in touch with technology with 3 00:00:09,039 --> 00:00:18,040 Speaker 1: tech Stuff from how stuff works dot com. Hello again, everyone, 4 00:00:18,040 --> 00:00:20,320 Speaker 1: and welcome to tech stuff. My name is Chris Polette 5 00:00:20,360 --> 00:00:22,439 Speaker 1: and I am an editor at how stuff works dot com. 6 00:00:22,840 --> 00:00:26,320 Speaker 1: Sitting across from me again as usual, with another bright idea, 7 00:00:26,480 --> 00:00:30,040 Speaker 1: is senior writer Jonathan Strickland. Back in the sixties, I 8 00:00:30,040 --> 00:00:32,960 Speaker 1: had a weather changing machine that was, in essence, a 9 00:00:33,000 --> 00:00:39,280 Speaker 1: sophisticated heat beam, which we called a laser. Using these lasers, 10 00:00:39,600 --> 00:00:41,880 Speaker 1: we punch a hole in the protective layer around the Earth, 11 00:00:41,920 --> 00:00:46,560 Speaker 1: which we scientists call the ozone layer. Slowly but surely, 12 00:00:46,640 --> 00:00:49,479 Speaker 1: ultra violet rays would pour in, increasing the risk of 13 00:00:49,479 --> 00:00:51,920 Speaker 1: skin cancer. That is, unless the world pays us a 14 00:00:51,960 --> 00:00:57,920 Speaker 1: hefty ransom. Joy that was an easy one, you know, 15 00:00:58,000 --> 00:01:00,880 Speaker 1: I Yeah, that's true. You know it's one because we 16 00:01:00,960 --> 00:01:03,600 Speaker 1: sort of obfuscate as to what the topic of the 17 00:01:03,680 --> 00:01:05,760 Speaker 1: show is going to be when we start, not just 18 00:01:05,920 --> 00:01:12,080 Speaker 1: time yet you could probably read it before you even sure, 19 00:01:12,480 --> 00:01:14,880 Speaker 1: and you just don't don't mean it. Yes, well, obviously 20 00:01:14,920 --> 00:01:18,400 Speaker 1: we're gonna be talking about weather changing technology. Yes, now 21 00:01:18,520 --> 00:01:21,600 Speaker 1: we're gonna talk about lasers, and this comes from a 22 00:01:21,600 --> 00:01:26,720 Speaker 1: little Facebook feedback, you be, Nathan had this to say, 23 00:01:26,760 --> 00:01:29,280 Speaker 1: how do lasers work? How does the lights stay in 24 00:01:29,280 --> 00:01:31,520 Speaker 1: a straight line? What makes them different than a beam 25 00:01:31,560 --> 00:01:34,600 Speaker 1: of light? Well, Nathan, we thought we would tackle this, 26 00:01:34,680 --> 00:01:37,399 Speaker 1: and in order to explain lasers, we actually have to 27 00:01:37,720 --> 00:01:42,960 Speaker 1: first talk about atoms. Indeed, you wouldn't necessarily believe it 28 00:01:43,000 --> 00:01:47,199 Speaker 1: to be so um, you know, maybe not anyway, but yeah, 29 00:01:47,319 --> 00:01:52,040 Speaker 1: the the science behind lasers is very very tiny on 30 00:01:52,080 --> 00:01:54,720 Speaker 1: the atomic or molecular level, depending on what kind of 31 00:01:54,800 --> 00:01:57,080 Speaker 1: laser you're talking about, most of the scientists don't top 32 00:01:57,080 --> 00:02:02,440 Speaker 1: four ft ten. That's a lot at any rate, the 33 00:02:02,600 --> 00:02:06,560 Speaker 1: right right to Jonathan, if you sists. So let's just 34 00:02:06,600 --> 00:02:09,280 Speaker 1: do a little review on atomic science. This is this 35 00:02:09,320 --> 00:02:11,240 Speaker 1: is from a high level. So anyone who has taken 36 00:02:11,240 --> 00:02:13,560 Speaker 1: any kind of science classes where you've talked about atoms, 37 00:02:13,560 --> 00:02:15,360 Speaker 1: this is going to be very familiar to you. But 38 00:02:15,480 --> 00:02:17,119 Speaker 1: just just bear with us, because you have to start 39 00:02:17,200 --> 00:02:19,480 Speaker 1: from somewhere right. Yeah, and and not all of our 40 00:02:19,480 --> 00:02:23,040 Speaker 1: listeners are necessarily going to know this. So the atom 41 00:02:23,200 --> 00:02:26,880 Speaker 1: is comprised of a nucleus, which is at least one 42 00:02:26,960 --> 00:02:29,800 Speaker 1: proton and usually a pro some protons and some neutrons. 43 00:02:29,840 --> 00:02:33,760 Speaker 1: Protons being the positively charged sub atomic particles, neutrons being 44 00:02:34,000 --> 00:02:37,320 Speaker 1: having no charge, and then there are it's surrounded by 45 00:02:37,320 --> 00:02:40,440 Speaker 1: a cloud of electrons, yes, and the electrons are the 46 00:02:40,480 --> 00:02:43,480 Speaker 1: negatively charged particles. So you have with a with a 47 00:02:43,600 --> 00:02:47,880 Speaker 1: standard atom in its elemental form, you have no net 48 00:02:48,080 --> 00:02:52,119 Speaker 1: charge because the the protons and electrons cancel one another out. 49 00:02:52,880 --> 00:02:57,120 Speaker 1: Now the electrons. Uh, it's this gets a little complicated. 50 00:02:57,160 --> 00:02:59,960 Speaker 1: We have to kind of simplify things. Imagine that electra 51 00:03:00,040 --> 00:03:04,680 Speaker 1: ons orbit the nucleus at different shells, Like there's a 52 00:03:04,720 --> 00:03:07,840 Speaker 1: there's a shell that's a certain distance from the nucleus, 53 00:03:07,880 --> 00:03:10,640 Speaker 1: and then there's another shell further out, and another shell 54 00:03:10,680 --> 00:03:14,280 Speaker 1: further out, and only so many electrons can occupy each 55 00:03:14,400 --> 00:03:17,840 Speaker 1: shell at a single time. Yeah, they really the orbit 56 00:03:17,880 --> 00:03:21,000 Speaker 1: the nucleus in a way that uh, in which you know, 57 00:03:21,040 --> 00:03:25,440 Speaker 1: for the more complex types of atoms, you you have 58 00:03:25,520 --> 00:03:28,399 Speaker 1: some that are closer to the nucleus than others. They're 59 00:03:28,440 --> 00:03:31,160 Speaker 1: just not room enough in that orbit for those other 60 00:03:31,280 --> 00:03:33,760 Speaker 1: electrons to be. And it's funny because you think about 61 00:03:33,760 --> 00:03:35,600 Speaker 1: it in a three dimensional sense, and it's far more 62 00:03:35,600 --> 00:03:38,520 Speaker 1: complex than the diagrams we've used to have to make 63 00:03:38,520 --> 00:03:40,880 Speaker 1: in chemistry class, right with the circles and the larger 64 00:03:40,920 --> 00:03:43,280 Speaker 1: circles and the larger circles. But if you think about 65 00:03:43,280 --> 00:03:46,600 Speaker 1: I mean, these electrons are negatively charged, right right, So 66 00:03:46,640 --> 00:03:49,760 Speaker 1: that means that they repel one another like repels like. 67 00:03:50,240 --> 00:03:53,120 Speaker 1: So that's why you can only have so many electrons 68 00:03:53,160 --> 00:03:56,920 Speaker 1: within that physical space, because they're gonna be pushing against 69 00:03:57,000 --> 00:04:00,440 Speaker 1: one another as they're rotating as the orbiting I shouldn't 70 00:04:00,440 --> 00:04:04,880 Speaker 1: say rotating as they're orbiting the nucleus. M Now here's 71 00:04:04,920 --> 00:04:07,440 Speaker 1: the interesting thing is that the if you if you 72 00:04:07,920 --> 00:04:12,600 Speaker 1: inject energy into an atom, what's your what happens is 73 00:04:12,640 --> 00:04:16,120 Speaker 1: that those electrons will elevate to a higher energy state, 74 00:04:16,200 --> 00:04:19,120 Speaker 1: so they will actually move further away from the nucleus. 75 00:04:19,520 --> 00:04:22,320 Speaker 1: If you, if you inject enough energy into an atom, 76 00:04:22,360 --> 00:04:25,600 Speaker 1: it will lose its electrons, or at least some electrons. 77 00:04:25,640 --> 00:04:29,520 Speaker 1: That's how we generate electricity. So but if you if 78 00:04:29,560 --> 00:04:31,760 Speaker 1: you don't do that much, if you just generate enough 79 00:04:31,760 --> 00:04:34,040 Speaker 1: where it's the electron has been pushed out to one 80 00:04:34,040 --> 00:04:37,400 Speaker 1: of the outer energy levels, and then you then remove 81 00:04:37,480 --> 00:04:40,880 Speaker 1: that that source of energy, the electron will naturally come 82 00:04:40,920 --> 00:04:45,760 Speaker 1: back down to its ground energy state. But we know 83 00:04:45,839 --> 00:04:48,920 Speaker 1: about the law of conservation of energy, right, you can't 84 00:04:49,040 --> 00:04:51,400 Speaker 1: that energy that you injected into the atom. It has 85 00:04:51,480 --> 00:04:54,320 Speaker 1: to come back somehow. Well, in this case, when the 86 00:04:54,360 --> 00:04:57,600 Speaker 1: electron comes back down to its ground state, it emits 87 00:04:57,720 --> 00:05:00,919 Speaker 1: a photon, which is a light particle. M hm. And 88 00:05:01,000 --> 00:05:03,680 Speaker 1: you know who had this idea way back in the day, 89 00:05:03,760 --> 00:05:07,720 Speaker 1: would it be Mr Albert Einstein? Yes, yes, uh you know, 90 00:05:07,760 --> 00:05:10,120 Speaker 1: of course we have an article about lasers on how 91 00:05:10,120 --> 00:05:12,520 Speaker 1: Stuff Works dot com. But I wanted to go, um 92 00:05:12,839 --> 00:05:14,839 Speaker 1: see what Britannica had to say about it, because I 93 00:05:14,839 --> 00:05:18,640 Speaker 1: thought that would be a good general explanation for lasers. UM. 94 00:05:18,680 --> 00:05:23,080 Speaker 1: And it was Albert Einstein who in nineteen sixteen figured that, uh, 95 00:05:23,160 --> 00:05:26,960 Speaker 1: you know, he he noticed that that adams could release 96 00:05:27,080 --> 00:05:32,080 Speaker 1: light when they were stimulated by light. UM. And you 97 00:05:32,080 --> 00:05:36,919 Speaker 1: know it was Rudolph Walter Leidenburg who actually saw it happen. 98 00:05:37,360 --> 00:05:40,080 Speaker 1: He was he was doing some experiments UM. And for 99 00:05:40,120 --> 00:05:42,080 Speaker 1: a while, this this phenomenon, it was just sort of 100 00:05:42,080 --> 00:05:45,159 Speaker 1: a something that we knew. It wasn't anything that we 101 00:05:45,279 --> 00:05:48,000 Speaker 1: did something with you, oh, let's go build some lasers. 102 00:05:48,080 --> 00:05:51,920 Speaker 1: In fact, there's a natural phenomenon that happens, uh that 103 00:05:52,080 --> 00:05:54,200 Speaker 1: you can you can observe if you're far enough to 104 00:05:54,240 --> 00:05:56,880 Speaker 1: the north or to the south on the Earth, which 105 00:05:56,880 --> 00:05:59,359 Speaker 1: are the northern and southern lights of the Aurora borealis 106 00:05:59,400 --> 00:06:02,680 Speaker 1: and the Aurora astralis. And the reason for this is 107 00:06:02,720 --> 00:06:04,920 Speaker 1: that you know, the Earth has a magnetic field, and 108 00:06:04,960 --> 00:06:08,039 Speaker 1: that magnetic field converges at the north and south poles, 109 00:06:08,080 --> 00:06:11,960 Speaker 1: the magnetic north and South poles and UH, and sometimes 110 00:06:12,000 --> 00:06:14,680 Speaker 1: that magnetic field gets disrupted, for example, when there's a 111 00:06:14,720 --> 00:06:17,920 Speaker 1: solar flare, and sometimes the solar flare will send enough 112 00:06:18,000 --> 00:06:21,480 Speaker 1: energy to Earth that it it kind of uh will 113 00:06:22,520 --> 00:06:26,680 Speaker 1: twist the magnetic field will realign earth magnetic field that 114 00:06:26,720 --> 00:06:29,359 Speaker 1: tends to dump a lot of energy into the ionosphere, 115 00:06:29,760 --> 00:06:33,560 Speaker 1: and the particles in the ionosphere they'll this is what happens. 116 00:06:33,560 --> 00:06:36,640 Speaker 1: The electrons get elevated to a higher energy state when 117 00:06:37,040 --> 00:06:41,560 Speaker 1: the atoms calm down, essentially they emit photons and we 118 00:06:41,560 --> 00:06:44,320 Speaker 1: we can see that invisible light. And that's when you know, 119 00:06:44,360 --> 00:06:46,080 Speaker 1: if you're at far off to the north and you 120 00:06:46,120 --> 00:06:49,039 Speaker 1: look off and you see these bright flashing lights in 121 00:06:49,040 --> 00:06:52,880 Speaker 1: the sky and they're all these pretty colors, that's what's happening. 122 00:06:52,920 --> 00:06:56,760 Speaker 1: It's actually the same phenomenon that we use to to 123 00:06:57,120 --> 00:07:04,080 Speaker 1: create a laser UM. So in more to laser history UM, 124 00:07:04,080 --> 00:07:08,960 Speaker 1: it was Columbia University's Charles H. Towns who decided to 125 00:07:09,040 --> 00:07:14,120 Speaker 1: try working on atoms at microwave frequencies UM and he 126 00:07:14,160 --> 00:07:16,880 Speaker 1: actually demonstrated in nineteen fifty three that it could be done. 127 00:07:16,920 --> 00:07:20,360 Speaker 1: Except he called his a mazer for microwave amplification by 128 00:07:20,360 --> 00:07:25,320 Speaker 1: the stimulated emission of radiation UM, and he actually got 129 00:07:25,320 --> 00:07:29,200 Speaker 1: the nineteen sixty four Nobel Price or physics UM. Also 130 00:07:30,080 --> 00:07:35,560 Speaker 1: UH Alexander Prokarov and Nikolai Bessov of the PM Lebedev 131 00:07:35,680 --> 00:07:38,720 Speaker 1: Physical Institute in Moscow, who also we're working on the 132 00:07:38,720 --> 00:07:42,000 Speaker 1: problem independently, none of it when it seems weird that 133 00:07:42,080 --> 00:07:45,960 Speaker 1: all these things happen simultaneously, Like we we talked about 134 00:07:46,520 --> 00:07:50,040 Speaker 1: the development of television. How two different people are credited 135 00:07:50,040 --> 00:07:52,360 Speaker 1: with the invention of television depending on whom you ask. 136 00:07:52,480 --> 00:07:55,800 Speaker 1: Shout out to Philo. Yeah, it's just it's just funny 137 00:07:55,800 --> 00:07:57,880 Speaker 1: that that UM, and this happens all the time in 138 00:07:58,040 --> 00:08:02,960 Speaker 1: the development of calculus. But yeah, we weird. Way to 139 00:08:03,000 --> 00:08:05,720 Speaker 1: go Newton, like, can we have a clear winner please? Anyway, 140 00:08:06,280 --> 00:08:08,400 Speaker 1: I'm sorry, but yes, I was gonna say so, yes, 141 00:08:08,440 --> 00:08:11,520 Speaker 1: you you were mentioning the maser that that also is 142 00:08:11,560 --> 00:08:13,960 Speaker 1: something we should point out that laser itself is an 143 00:08:13,960 --> 00:08:20,640 Speaker 1: acronym light amplification by stimulated emission of radiation. You can 144 00:08:20,640 --> 00:08:24,120 Speaker 1: see why laser was picked over that. Yea, And uh, 145 00:08:24,280 --> 00:08:27,280 Speaker 1: do you have who made the first true laser um? 146 00:08:27,320 --> 00:08:29,680 Speaker 1: I do have the first the person who made the 147 00:08:29,680 --> 00:08:34,920 Speaker 1: first true laser um. Well, if you're talking about Gordon Gould, 148 00:08:34,960 --> 00:08:37,040 Speaker 1: that is Oh, that wasn't who I have, But go ahead. 149 00:08:37,200 --> 00:08:39,440 Speaker 1: He is the person who actually got he called it 150 00:08:39,640 --> 00:08:42,839 Speaker 1: the laser um. He's the person who filed for the patent. Now, 151 00:08:43,320 --> 00:08:45,880 Speaker 1: if you're talking about Towns again, he was working with 152 00:08:46,240 --> 00:08:50,160 Speaker 1: Arthur L. Shallow, who was his brother in law UM, 153 00:08:50,320 --> 00:08:52,840 Speaker 1: and they were looking at the infrared light and visible 154 00:08:53,120 --> 00:08:59,480 Speaker 1: light wavelengths. And in December they published a and an 155 00:08:59,480 --> 00:09:02,600 Speaker 1: issue of Physical Review was published and their paper was 156 00:09:02,679 --> 00:09:06,840 Speaker 1: in it. UM. But Gordon Gould actually had his patents 157 00:09:06,880 --> 00:09:09,520 Speaker 1: granted in the nineteen seventies and he's the one who 158 00:09:09,559 --> 00:09:12,560 Speaker 1: made most of the money off of it. Because masers 159 00:09:12,600 --> 00:09:16,000 Speaker 1: had actually been used in atomic clocks and microwave amplifiers, 160 00:09:16,000 --> 00:09:18,719 Speaker 1: but they really weren't using them for much else. And 161 00:09:18,840 --> 00:09:23,559 Speaker 1: lasers which use a different wavelengths of light um there, 162 00:09:23,600 --> 00:09:26,600 Speaker 1: you can use them in different applications, and that's why 163 00:09:26,840 --> 00:09:28,720 Speaker 1: this was so profitable. Are those the people that you 164 00:09:28,760 --> 00:09:31,520 Speaker 1: had in Actually, the one I have specifically was a 165 00:09:31,520 --> 00:09:34,679 Speaker 1: fellow who in nineteen sixty built a laser out of 166 00:09:34,720 --> 00:09:39,800 Speaker 1: a synthetic ruby. Ah, you're talking about THEO yeah, Teddy 167 00:09:40,320 --> 00:09:43,800 Speaker 1: Theodore Mayman. Yes, and uh, that would be the fellow 168 00:09:43,840 --> 00:09:47,560 Speaker 1: who created the first true laser using a synthetic ruby. 169 00:09:47,559 --> 00:09:49,880 Speaker 1: Now right now that that's the kind of laser that 170 00:09:49,920 --> 00:09:52,520 Speaker 1: I think of as being the modern the kind of 171 00:09:52,600 --> 00:09:55,160 Speaker 1: laser were used today. Although he when I think it's 172 00:09:55,200 --> 00:09:58,280 Speaker 1: kind of interesting, he used a photographer's flash, Yeah, as 173 00:09:58,280 --> 00:10:01,199 Speaker 1: a source of stimulation for chromium atoms in a in 174 00:10:01,240 --> 00:10:05,280 Speaker 1: a ruby crystal, synthetic ruby crystal. So when you when 175 00:10:05,280 --> 00:10:08,160 Speaker 1: you're talking about creating a laser, the first step is 176 00:10:08,240 --> 00:10:11,040 Speaker 1: you have to have some sort of medium that you 177 00:10:11,080 --> 00:10:14,160 Speaker 1: are going to, uh, you're going to apply energy to 178 00:10:14,400 --> 00:10:17,200 Speaker 1: in order to excite the atoms within that medium. And 179 00:10:17,200 --> 00:10:20,520 Speaker 1: I understand that's called a game medium and also sometimes 180 00:10:20,559 --> 00:10:25,559 Speaker 1: called a lazing medium. So yeah, and you the the 181 00:10:25,600 --> 00:10:29,120 Speaker 1: process of pouring energy into this is called actually it's 182 00:10:29,120 --> 00:10:33,439 Speaker 1: called pumping. You pump the lazing medium to generate photons. 183 00:10:34,040 --> 00:10:37,479 Speaker 1: That's that. That's a verbie often associate with super soakers, 184 00:10:38,960 --> 00:10:44,760 Speaker 1: I associated with nikes, these old air nikes. Um. But 185 00:10:44,880 --> 00:10:47,440 Speaker 1: the uh yeah, so you what you do is you 186 00:10:47,480 --> 00:10:51,000 Speaker 1: have to generate enough energy within this lazing medium so 187 00:10:51,040 --> 00:10:54,920 Speaker 1: that you're starting to push the electrons into the higher 188 00:10:55,000 --> 00:10:58,520 Speaker 1: orbits or the higher energy states, I should say. And 189 00:10:59,440 --> 00:11:02,280 Speaker 1: what's interest thing is that if the once they the 190 00:11:02,640 --> 00:11:05,679 Speaker 1: electrons start coming back down and photons are admitted. If 191 00:11:05,720 --> 00:11:08,800 Speaker 1: you've if you've arranged the material the right way, the 192 00:11:08,840 --> 00:11:12,760 Speaker 1: medium the right way, and you have it uh contained properly, 193 00:11:13,280 --> 00:11:17,840 Speaker 1: those photons when they strike other atoms will excite the 194 00:11:17,920 --> 00:11:22,720 Speaker 1: atoms they hit, which will then generate their own photons. So, UM, 195 00:11:22,760 --> 00:11:25,480 Speaker 1: it's not self sustaining. It's not gonna stay that way forever. 196 00:11:25,520 --> 00:11:29,559 Speaker 1: You're gonna lose energy eventually through various means. But that 197 00:11:29,559 --> 00:11:33,160 Speaker 1: that helps you. That's why it's called stimulated emission of radiation. 198 00:11:33,679 --> 00:11:36,760 Speaker 1: It's it's you stimulate the emission and then the process 199 00:11:36,800 --> 00:11:41,040 Speaker 1: starts to help sustain itself. UM. Now, with a laser 200 00:11:41,120 --> 00:11:44,760 Speaker 1: you typically happen to have mirrors on either side of 201 00:11:44,840 --> 00:11:49,400 Speaker 1: the lasing medium. So um when the photons start to 202 00:11:50,320 --> 00:11:53,319 Speaker 1: travel through the medium, And by the way, another interesting 203 00:11:53,360 --> 00:11:56,920 Speaker 1: thing here is that when a photon hits another atom 204 00:11:57,000 --> 00:12:00,040 Speaker 1: um and excites the electron, and then the electro and 205 00:12:00,120 --> 00:12:03,000 Speaker 1: comes back down to its ground state and it emits 206 00:12:03,040 --> 00:12:06,440 Speaker 1: another photon, that second photon is going to travel in 207 00:12:06,480 --> 00:12:09,559 Speaker 1: the same direction as the first photon, the one that 208 00:12:09,640 --> 00:12:11,280 Speaker 1: hit it the first time. So if you think about it, 209 00:12:11,320 --> 00:12:15,320 Speaker 1: think of like a series of um of billiard balls 210 00:12:15,840 --> 00:12:21,280 Speaker 1: rights right physics, and just imagine that you somehow manage 211 00:12:21,440 --> 00:12:24,920 Speaker 1: to line up those billiard ball balls absolutely perfectly and 212 00:12:24,920 --> 00:12:28,120 Speaker 1: and they hit exactly the right way, so that when 213 00:12:28,120 --> 00:12:30,559 Speaker 1: the first billiard ball connects with a second, the second 214 00:12:30,559 --> 00:12:32,640 Speaker 1: one continues to travel on the straight line from the 215 00:12:32,640 --> 00:12:35,680 Speaker 1: first one hits the third, third one continues hit going 216 00:12:35,720 --> 00:12:38,400 Speaker 1: a straight line, hits the fourth, and it just becomes 217 00:12:38,400 --> 00:12:42,000 Speaker 1: this chain reaction. Now, because there's a mirror on either end, 218 00:12:42,520 --> 00:12:44,880 Speaker 1: there's actually a complete mirror on one end and a 219 00:12:44,960 --> 00:12:47,880 Speaker 1: partial mirror on the other. Um, the photons when they 220 00:12:47,960 --> 00:12:50,680 Speaker 1: hit the end are reflected back into the medium, and 221 00:12:50,720 --> 00:12:53,719 Speaker 1: then it continues to create these this flow of photons. 222 00:12:54,280 --> 00:12:57,719 Speaker 1: Now that partial mirror on the other side allows some 223 00:12:57,800 --> 00:13:02,040 Speaker 1: photons to pass through, right, and they're all traveling in 224 00:13:02,080 --> 00:13:07,000 Speaker 1: that one specific direction. It's a very intense, uh, coherent 225 00:13:07,960 --> 00:13:10,360 Speaker 1: part of a beam of light. Now, this is the 226 00:13:10,440 --> 00:13:13,960 Speaker 1: light traveling in a straight direction that Nathan was Yes, Yes, 227 00:13:14,040 --> 00:13:17,080 Speaker 1: this is it's coherence is the concept we're talking about here. 228 00:13:17,080 --> 00:13:20,360 Speaker 1: It's it's organized, right, So every photon is moving in 229 00:13:20,400 --> 00:13:24,559 Speaker 1: the same direction as opposed to a flashlight, which is diffuse. Right. 230 00:13:24,640 --> 00:13:27,000 Speaker 1: That and for one thing that the flashlight, when the 231 00:13:27,000 --> 00:13:30,160 Speaker 1: photons are emitted, they're emitted in a more random pattern. 232 00:13:30,520 --> 00:13:33,480 Speaker 1: They're not directed like in a laser. And you may 233 00:13:33,520 --> 00:13:36,720 Speaker 1: even also have a lens that will focus that beam further, 234 00:13:37,200 --> 00:13:42,680 Speaker 1: depending upon what application you have in mind for this laser. 235 00:13:43,000 --> 00:13:46,599 Speaker 1: Like a laser pointer doesn't need to to focus the 236 00:13:46,679 --> 00:13:49,600 Speaker 1: laser in a really intense beam because you're using it 237 00:13:49,640 --> 00:13:51,240 Speaker 1: just to point stuff out and you don't want to 238 00:13:51,280 --> 00:13:54,280 Speaker 1: burn a hole through the wall. Right. Yeah, that's that's 239 00:13:54,320 --> 00:13:56,439 Speaker 1: the type of laser that I own. I have a 240 00:13:57,040 --> 00:13:59,559 Speaker 1: red laser at home that I used to h to 241 00:13:59,679 --> 00:14:03,280 Speaker 1: drive my cats crazy, yes, um, which they very very 242 00:14:03,360 --> 00:14:05,439 Speaker 1: much enjoy and it also doubles nicely as a laser 243 00:14:05,480 --> 00:14:09,120 Speaker 1: pointer if you happen to need one. But that's um, 244 00:14:09,160 --> 00:14:11,840 Speaker 1: you know, they're they're fairly inexpensive because they don't need 245 00:14:11,920 --> 00:14:18,600 Speaker 1: a lot of um high end parts if you will. Um, yeah, 246 00:14:18,640 --> 00:14:22,280 Speaker 1: it's and it really depends two on the type of laser. 247 00:14:22,400 --> 00:14:24,240 Speaker 1: I mean, they're there are a lot of things that 248 00:14:24,280 --> 00:14:30,120 Speaker 1: you can change, um about lasers to change a number 249 00:14:30,120 --> 00:14:33,080 Speaker 1: of things like um, the size of the beam and 250 00:14:33,360 --> 00:14:35,280 Speaker 1: the color, because it has a lot to do with 251 00:14:35,320 --> 00:14:37,520 Speaker 1: the medium. Yeah, we should actually point that out. In fact, 252 00:14:37,520 --> 00:14:39,560 Speaker 1: I'm glad you mentioned that because I forgot to say that. 253 00:14:40,000 --> 00:14:42,880 Speaker 1: The other interesting thing about a laser is that they 254 00:14:42,880 --> 00:14:45,920 Speaker 1: are monochromatic. They are all of a single color. Now 255 00:14:45,960 --> 00:14:48,120 Speaker 1: that color may not even be within the spectrum of 256 00:14:48,160 --> 00:14:50,840 Speaker 1: what we can view. It might be not not not 257 00:14:50,960 --> 00:14:53,880 Speaker 1: with invisible light, because you can have ultra violet lasers, 258 00:14:53,960 --> 00:14:58,720 Speaker 1: you can have infrared lasers. But the color is dependent 259 00:14:58,880 --> 00:15:02,840 Speaker 1: mainly upon the the state, the energy state of the electrons, 260 00:15:03,400 --> 00:15:06,880 Speaker 1: and a lot of that will depend upon what specific 261 00:15:07,520 --> 00:15:12,120 Speaker 1: medium you are using as your lasing medium. Because the 262 00:15:13,200 --> 00:15:16,320 Speaker 1: you know, different atoms have different number of electrons, so 263 00:15:16,400 --> 00:15:20,040 Speaker 1: therefore the the state. The various energy states are going 264 00:15:20,040 --> 00:15:25,280 Speaker 1: to be different depending upon which elements you're using. So um, Yeah. 265 00:15:25,320 --> 00:15:29,920 Speaker 1: For example, a carbon dioxide laser is often used in 266 00:15:30,160 --> 00:15:36,600 Speaker 1: cutting applications, and it's um, it's it's a it's got 267 00:15:36,600 --> 00:15:39,640 Speaker 1: a very large wavelength. The wavelength that we were talking 268 00:15:39,640 --> 00:15:43,160 Speaker 1: about earlier, of course, that's talking about how long the 269 00:15:43,440 --> 00:15:48,680 Speaker 1: a particular peak and trough of Yeah, that would be 270 00:15:48,720 --> 00:15:52,480 Speaker 1: a wave. Uh you know that that determines a lot 271 00:15:52,560 --> 00:15:56,840 Speaker 1: of different properties of lasers. Red lasers tend to have 272 00:15:56,880 --> 00:16:01,200 Speaker 1: a wavelength of around six and ninety four nanometers or gnometers, 273 00:16:01,640 --> 00:16:04,720 Speaker 1: depending on how you prefer it. Um. And remember a 274 00:16:04,800 --> 00:16:08,480 Speaker 1: nanometer is one billionth of a meter. It's tiny, tiny, tiny, 275 00:16:08,920 --> 00:16:12,560 Speaker 1: still big compared to the atomic scale. In the atomic 276 00:16:12,560 --> 00:16:17,360 Speaker 1: scale is about a tenth the size of the nanoscale. So, 277 00:16:19,320 --> 00:16:21,880 Speaker 1: like we said, depending on the medium, that's what's going 278 00:16:21,920 --> 00:16:25,120 Speaker 1: to determine kind of the wavelength and therefore the color 279 00:16:25,360 --> 00:16:28,960 Speaker 1: of the laser. So if you're using something like argon 280 00:16:29,080 --> 00:16:31,680 Speaker 1: fluoride for your laser is going to be in the 281 00:16:31,760 --> 00:16:36,160 Speaker 1: ultraviolet range, which means the wavelength is around ter So 282 00:16:36,480 --> 00:16:39,600 Speaker 1: that's a tiny, tiny wavelength. The carbon dioxide one is 283 00:16:39,640 --> 00:16:45,560 Speaker 1: ten six hundred nanometers, so that's quite a long wavelength. 284 00:16:45,960 --> 00:16:49,000 Speaker 1: And then the stuff that we can see like the 285 00:16:49,040 --> 00:16:53,680 Speaker 1: typical red laser that might be a helium neon laser, 286 00:16:53,760 --> 00:16:58,240 Speaker 1: that that's one that can produce a red color and 287 00:16:58,280 --> 00:17:03,720 Speaker 1: that's around six and thirty three amnometers in wavelength. So uh, 288 00:17:03,960 --> 00:17:07,080 Speaker 1: that's to me, that's a really interesting idea is the 289 00:17:07,119 --> 00:17:09,720 Speaker 1: fact that you know, just by experimenting with different mediums 290 00:17:09,800 --> 00:17:14,080 Speaker 1: or media I should say not mediums, Um, we've determined 291 00:17:14,119 --> 00:17:16,560 Speaker 1: that you can create different colors of lasers and and 292 00:17:16,600 --> 00:17:19,600 Speaker 1: depending and the lasers themselves have different properties that are 293 00:17:19,680 --> 00:17:24,600 Speaker 1: valuable in various applications. Yep. Um. And it it's worth 294 00:17:24,760 --> 00:17:28,520 Speaker 1: noting to um that you mean you could use gases, 295 00:17:28,560 --> 00:17:33,040 Speaker 1: solids or liquids as a medium for for lasers, and 296 00:17:33,280 --> 00:17:36,800 Speaker 1: most of the ones we use our gas, um liquids 297 00:17:36,840 --> 00:17:40,800 Speaker 1: are are the least common from what I understand from 298 00:17:40,840 --> 00:17:44,959 Speaker 1: my research. But UM, yeah, it's uh, it's funny because 299 00:17:45,320 --> 00:17:48,240 Speaker 1: it really the color laser too. You might go on 300 00:17:48,400 --> 00:17:53,000 Speaker 1: to uh shopping sites where they have geek toys and 301 00:17:53,119 --> 00:17:54,720 Speaker 1: uh and look at them and go, well, you know, 302 00:17:54,760 --> 00:17:58,560 Speaker 1: the laser laser pointers like five dollars for a red one, 303 00:17:58,920 --> 00:18:02,800 Speaker 1: but it's ninety or a hundred fifty dollars for blue 304 00:18:02,960 --> 00:18:05,040 Speaker 1: or violet or you know what, what is the deal 305 00:18:05,080 --> 00:18:08,879 Speaker 1: with that? Well? Um, I think part of that is 306 00:18:08,920 --> 00:18:12,800 Speaker 1: that some are easier to make than others. Um. Part 307 00:18:12,800 --> 00:18:16,000 Speaker 1: of that is probably the medium to scarcity of the 308 00:18:16,040 --> 00:18:19,600 Speaker 1: medium and part of its demand. Um. And I think 309 00:18:19,640 --> 00:18:23,040 Speaker 1: part of it also is how cool they look and 310 00:18:23,080 --> 00:18:26,040 Speaker 1: how new they are, because um, now the red lasers 311 00:18:26,480 --> 00:18:30,560 Speaker 1: red laser pointers have been available for so long. Um, 312 00:18:30,600 --> 00:18:32,640 Speaker 1: you know, they're pretty common. I mean you could get 313 00:18:32,680 --> 00:18:34,240 Speaker 1: I I picked mine up as a matter of fact, 314 00:18:34,280 --> 00:18:37,360 Speaker 1: in the grocery store in the pet section. Um. But yeah, 315 00:18:37,400 --> 00:18:39,200 Speaker 1: if you want to, if you want to violate laser, 316 00:18:39,560 --> 00:18:42,640 Speaker 1: they're harder to find. Um. Yeah, I haven't been out 317 00:18:42,680 --> 00:18:45,240 Speaker 1: as long, and they're kind of expensive. Hear, Mace Window 318 00:18:45,320 --> 00:18:47,560 Speaker 1: had to drop three Corelian Freighters in order to get 319 00:18:47,600 --> 00:18:51,080 Speaker 1: his lightsaber. You know, I almost mentioned lightsabers and whether 320 00:18:51,160 --> 00:18:53,239 Speaker 1: or not we were growing our own crystals or not 321 00:18:53,720 --> 00:18:55,760 Speaker 1: for this, and then I thought, I'll wait and see 322 00:18:55,760 --> 00:18:58,040 Speaker 1: if Jonathan mentions it. You can just listen to our 323 00:18:58,119 --> 00:19:00,159 Speaker 1: lightsaber podcast if you want to. That was that was 324 00:19:00,200 --> 00:19:02,560 Speaker 1: a fun one. But yeah, but yeah, it had these 325 00:19:02,600 --> 00:19:04,960 Speaker 1: these are these wavelengths, these lasers and different wavelengths are 326 00:19:05,000 --> 00:19:07,320 Speaker 1: great for different kinds of applications. True, because I know 327 00:19:07,359 --> 00:19:10,440 Speaker 1: you you were, you know, talking about Blu ray players 328 00:19:10,840 --> 00:19:16,240 Speaker 1: Blu ray versus DVD. Yeah, yeah, okay, so DVD players. Um, 329 00:19:16,280 --> 00:19:20,640 Speaker 1: the old DVD players used or still us really red 330 00:19:20,720 --> 00:19:24,879 Speaker 1: lasers to read information off of a DVD. And the 331 00:19:24,960 --> 00:19:28,240 Speaker 1: way this basically works is think of the DVD. It's 332 00:19:28,280 --> 00:19:30,399 Speaker 1: got a it's got a layer on the DVD that 333 00:19:30,480 --> 00:19:34,720 Speaker 1: has information that's recorded and essentially little pits. These little 334 00:19:34,760 --> 00:19:37,879 Speaker 1: pits are read as ones and zeros. What happens is 335 00:19:37,920 --> 00:19:41,520 Speaker 1: a laser will hit the pit or the blank space, 336 00:19:41,760 --> 00:19:44,600 Speaker 1: because that's also information. It's just saying it's a zero 337 00:19:44,720 --> 00:19:49,240 Speaker 1: rather than one. Essentially, I'm oversimplifying. Yes, yes, it's it's complicated. 338 00:19:49,280 --> 00:19:52,359 Speaker 1: But and there's a reflective surface that's beneath that layer. 339 00:19:53,000 --> 00:19:56,040 Speaker 1: So the laser hits the pit or the smooth space 340 00:19:56,119 --> 00:20:00,280 Speaker 1: hits the reflective surface, bounces back towards a cent sore. 341 00:20:01,040 --> 00:20:04,720 Speaker 1: Sincere I'm talking about lack lasers and sin sores, I 342 00:20:04,720 --> 00:20:07,679 Speaker 1: don't know what the heck's happened in me this morning, guys, anyway, 343 00:20:07,720 --> 00:20:10,120 Speaker 1: So the laser hits the pit, hits the reflective service, 344 00:20:10,200 --> 00:20:12,840 Speaker 1: bounces back hits the sensor. The sensor detects whether you 345 00:20:12,880 --> 00:20:15,520 Speaker 1: know what kind of element was on the DVD. That 346 00:20:15,560 --> 00:20:19,760 Speaker 1: gets translated into digital information, which then eventually becomes the 347 00:20:19,760 --> 00:20:23,719 Speaker 1: picture on your television screen. So with a red laser, 348 00:20:24,480 --> 00:20:27,119 Speaker 1: you remember, the red lasers wavelength is around six and 349 00:20:27,320 --> 00:20:31,120 Speaker 1: thirty three ninometers, So there's a certain amount of information 350 00:20:31,160 --> 00:20:35,280 Speaker 1: you could fit on a DVD single layer DVD UH 351 00:20:35,320 --> 00:20:39,000 Speaker 1: that you cannot exceed because the red lasers only able 352 00:20:39,040 --> 00:20:42,199 Speaker 1: to detect something of a size that its wavelength can 353 00:20:42,280 --> 00:20:45,119 Speaker 1: hit and bounce back from. Like if the pits were smaller, 354 00:20:45,160 --> 00:20:47,400 Speaker 1: the wavelength wouldn't even detect it because the wavelength would 355 00:20:47,400 --> 00:20:50,160 Speaker 1: be larger than the the actual element it was trying 356 00:20:50,200 --> 00:20:54,399 Speaker 1: to detect. Well, Blu ray players use a blue laser, 357 00:20:54,480 --> 00:20:58,520 Speaker 1: and blue lasers have a a smaller wavelength, shorter wavelength, 358 00:20:59,359 --> 00:21:04,200 Speaker 1: their wavelength around footers, So essentially you can cram more 359 00:21:04,240 --> 00:21:09,560 Speaker 1: information onto a blu ray disc because the wavelength is smaller, 360 00:21:10,160 --> 00:21:14,359 Speaker 1: and UH, you the path the pattern on the DVD 361 00:21:14,480 --> 00:21:18,480 Speaker 1: if you will, well, I mean, the disc itself is 362 00:21:18,760 --> 00:21:20,800 Speaker 1: doesn't have to be as large for the laser to 363 00:21:20,840 --> 00:21:23,120 Speaker 1: read it, so you can pack more information on there 364 00:21:23,160 --> 00:21:25,159 Speaker 1: because the blue lazer has no trouble reading it at 365 00:21:25,160 --> 00:21:27,680 Speaker 1: a smaller size. Exactly. Yeah, if you if you want 366 00:21:27,680 --> 00:21:30,040 Speaker 1: to think of it in h here's another weird way. 367 00:21:30,119 --> 00:21:32,720 Speaker 1: Think of it like a wall that's covered in in 368 00:21:33,400 --> 00:21:36,199 Speaker 1: in white and black dots. Alright, but the white and 369 00:21:36,200 --> 00:21:38,720 Speaker 1: black dots are maybe like a six inches in diameter. 370 00:21:39,119 --> 00:21:42,040 Speaker 1: So you're using a flashlight, and the flashlight is shooting 371 00:21:42,200 --> 00:21:44,560 Speaker 1: is has a has a circle of about six inches 372 00:21:44,600 --> 00:21:46,880 Speaker 1: in diameter from the distance that you're at the wall, 373 00:21:46,960 --> 00:21:50,600 Speaker 1: and you you you count the number of dots as 374 00:21:50,640 --> 00:21:55,040 Speaker 1: you swipe the flashlight left and right across the wall. Well, 375 00:21:55,080 --> 00:21:58,360 Speaker 1: then let's say that you've got another wall that has 376 00:21:58,440 --> 00:22:01,240 Speaker 1: dots that are two inches in diameter, and you've got 377 00:22:01,240 --> 00:22:03,920 Speaker 1: a flashlight and you've got a light that's two inches 378 00:22:03,960 --> 00:22:05,960 Speaker 1: in diameter. It's you're going to be able to count 379 00:22:06,160 --> 00:22:08,919 Speaker 1: way more dots on that wall than you could with 380 00:22:08,960 --> 00:22:10,919 Speaker 1: the ones that were six inches in diameter. That's the 381 00:22:10,960 --> 00:22:14,679 Speaker 1: same concept here. So it's interesting to me that just 382 00:22:14,760 --> 00:22:17,920 Speaker 1: by switching to a different kind of laser, we've been 383 00:22:17,960 --> 00:22:22,800 Speaker 1: able to cram more information in a storage medium. It's 384 00:22:22,840 --> 00:22:28,880 Speaker 1: a really neat idea. And we talked recently about light Peak, 385 00:22:29,119 --> 00:22:33,480 Speaker 1: which is now called Thunderbolt, at least as far as 386 00:22:33,800 --> 00:22:39,640 Speaker 1: Apple products because it's apparently got an exclusivity deal with Apple. Um. 387 00:22:39,680 --> 00:22:42,040 Speaker 1: But you we talked about light Peak a couple of 388 00:22:42,560 --> 00:22:51,480 Speaker 1: episodes ago, and light Peak uses um infrared Uh uh yeah, 389 00:22:51,600 --> 00:22:56,200 Speaker 1: infrared lasers instead of visible spectrum lasers. But it's same 390 00:22:56,240 --> 00:22:58,320 Speaker 1: sort of concept here is that it's using that to 391 00:22:58,840 --> 00:23:02,240 Speaker 1: shoot information sation from a chip to a device or 392 00:23:02,720 --> 00:23:06,560 Speaker 1: vice versa. Uh. The digital information gets translated into a 393 00:23:06,600 --> 00:23:09,879 Speaker 1: series of flashes of this laser, which get picked up 394 00:23:09,880 --> 00:23:16,600 Speaker 1: by another sensor and then transmitted back into digital information. Now, um, 395 00:23:16,720 --> 00:23:19,120 Speaker 1: there's something else I wanted to talk about that's related 396 00:23:19,160 --> 00:23:22,320 Speaker 1: but not exactly on topic, but it's it's very recent 397 00:23:22,400 --> 00:23:25,080 Speaker 1: and it's really cool, so I thought I would mention it. 398 00:23:25,080 --> 00:23:28,679 Speaker 1: It's okay with you? Please do have you heard about this? Uh? 399 00:23:28,720 --> 00:23:33,359 Speaker 1: This article that was published in the February issue of Science. 400 00:23:34,640 --> 00:23:37,760 Speaker 1: Is it about an anti laser? It is. I knew 401 00:23:37,760 --> 00:23:41,000 Speaker 1: about uncle laser, but I don't know anti laser very well. 402 00:23:41,080 --> 00:23:44,639 Speaker 1: Please all right, let in the interesting full full disclosure. 403 00:23:44,960 --> 00:23:47,240 Speaker 1: I have not read this article. I don't know anything 404 00:23:47,240 --> 00:23:50,240 Speaker 1: about it, but are one of our science editors, Alice 405 00:23:50,280 --> 00:23:53,040 Speaker 1: and louder Milk. She mentioned it to me this morning 406 00:23:53,040 --> 00:23:54,480 Speaker 1: and I thought, oh, I need to look that up, 407 00:23:54,520 --> 00:23:55,800 Speaker 1: and I just didn't have the time to do it. 408 00:23:55,840 --> 00:23:59,080 Speaker 1: So please tell me what is this? Well, I got 409 00:23:59,080 --> 00:24:02,399 Speaker 1: my information not from that particular article, but from the 410 00:24:02,480 --> 00:24:06,440 Speaker 1: Yale Daily News, an article by Antonio Woodford. Uh. And 411 00:24:06,440 --> 00:24:09,200 Speaker 1: and it's relevant to Yale because it's Yale physicists who 412 00:24:09,200 --> 00:24:11,199 Speaker 1: came up with this idea. It's it actually is a 413 00:24:11,240 --> 00:24:16,160 Speaker 1: device that absorbs light instead of emitting light. So that's 414 00:24:16,200 --> 00:24:18,160 Speaker 1: why people are calling at the anti laser. That isn't 415 00:24:18,200 --> 00:24:22,640 Speaker 1: it really what it is? A laser, you know, stimulates 416 00:24:22,880 --> 00:24:28,239 Speaker 1: atoms to to generate light UM and this absorbs light, 417 00:24:28,280 --> 00:24:30,240 Speaker 1: so they're calling it an anti lazer. But it's really 418 00:24:30,520 --> 00:24:32,840 Speaker 1: called and And the reason you'll you'll understand in the 419 00:24:32,880 --> 00:24:34,800 Speaker 1: second why people are calling at the anti laser because 420 00:24:34,960 --> 00:24:39,400 Speaker 1: it's a lot more fun to say than coherent perfect absorber. Yeah, 421 00:24:39,440 --> 00:24:43,399 Speaker 1: I know it's a scientific name. So anyway, um, Uh, 422 00:24:43,480 --> 00:24:48,360 Speaker 1: physicists Douglas Stone and we cow um, we're working on 423 00:24:48,560 --> 00:24:53,960 Speaker 1: a device that absorbs light and basically instead of using 424 00:24:54,040 --> 00:24:58,320 Speaker 1: a game medium, UH, it uses an absorbing medium instead. 425 00:24:58,720 --> 00:25:02,840 Speaker 1: So it's basically a chamber like a laser UM and 426 00:25:02,880 --> 00:25:06,200 Speaker 1: if you shoot two light beams into the two and 427 00:25:06,280 --> 00:25:09,520 Speaker 1: two ends both ends of the device, it will absorb 428 00:25:09,720 --> 00:25:16,880 Speaker 1: around four of infrared light. UM. And basically what happened 429 00:25:17,160 --> 00:25:22,080 Speaker 1: UH is Stone was trying to describe how lasers work 430 00:25:22,160 --> 00:25:23,960 Speaker 1: much as we are trying to do to someone else 431 00:25:24,000 --> 00:25:26,000 Speaker 1: and realize, you know what, I bet you could reverse 432 00:25:26,040 --> 00:25:30,000 Speaker 1: this process and have an absorb light. So as an experiment, 433 00:25:30,040 --> 00:25:34,560 Speaker 1: he decided to work on this and UM, basically you know, 434 00:25:34,600 --> 00:25:37,400 Speaker 1: it was successful in in creating a device that if 435 00:25:37,440 --> 00:25:41,320 Speaker 1: you um, you know, shown a uh an infrared light 436 00:25:41,359 --> 00:25:43,720 Speaker 1: into it, it would absorb the light. And you say, okay, 437 00:25:43,760 --> 00:25:45,520 Speaker 1: well that's a need experiment. But what can you do 438 00:25:45,600 --> 00:25:47,760 Speaker 1: with it? We remember when we were talking just a 439 00:25:47,760 --> 00:25:52,679 Speaker 1: moment ago about transmitting information via light peak or you 440 00:25:52,680 --> 00:25:55,280 Speaker 1: know the blue ray and DVD players. You're transmitting information 441 00:25:55,320 --> 00:26:00,520 Speaker 1: over the laser. UM. You can use uh the coherent 442 00:26:00,680 --> 00:26:04,480 Speaker 1: perfect absorber I'm sorry, anti laser. Yeah, it's not really 443 00:26:04,520 --> 00:26:07,360 Speaker 1: what it's called, but it's so much more fun. Yes, 444 00:26:07,400 --> 00:26:09,880 Speaker 1: it is. UM. You can use it to detect pollutants 445 00:26:09,920 --> 00:26:14,080 Speaker 1: in the air. And because it can basically by by 446 00:26:14,119 --> 00:26:17,439 Speaker 1: shining the light through the pollutants and having it in 447 00:26:17,800 --> 00:26:23,040 Speaker 1: uh end up in the coherent perfect absorber. Um. You know, 448 00:26:23,119 --> 00:26:25,960 Speaker 1: you you can pick up information from that. Also, you 449 00:26:25,960 --> 00:26:30,439 Speaker 1: can use it for wireless communications, transmitting information basically from 450 00:26:30,480 --> 00:26:32,359 Speaker 1: one point to the other with a light on one 451 00:26:32,480 --> 00:26:35,400 Speaker 1: end and the absorber on the other end. Um. So 452 00:26:35,480 --> 00:26:38,520 Speaker 1: they said. Also it could be used in optical computer chips. 453 00:26:38,520 --> 00:26:40,720 Speaker 1: So that will give you another article to write, and 454 00:26:40,840 --> 00:26:42,960 Speaker 1: maybe this time they won't change the name at the 455 00:26:43,000 --> 00:26:46,080 Speaker 1: last minute. I have another possible use for it. Okay, 456 00:26:46,200 --> 00:26:47,880 Speaker 1: you could use it to coat your car and then 457 00:26:47,920 --> 00:26:50,119 Speaker 1: the cops can't tell how fast you're going using a 458 00:26:50,200 --> 00:26:54,600 Speaker 1: laser speed detector. I'm betting that that's not gonna work. 459 00:26:54,640 --> 00:26:57,760 Speaker 1: It's like a stealth car. It's brilliant. I'll make a billion. 460 00:26:57,880 --> 00:27:01,359 Speaker 1: No one steal that. But yeah, they can use it 461 00:27:01,400 --> 00:27:03,479 Speaker 1: in they think they can use in an optical computer 462 00:27:03,560 --> 00:27:07,800 Speaker 1: chips by change to to change light into electricity. Um. 463 00:27:07,920 --> 00:27:10,120 Speaker 1: So it's you know, it's not just an experiment. It's 464 00:27:10,160 --> 00:27:13,560 Speaker 1: something they think they can uh you know, put into 465 00:27:13,560 --> 00:27:15,879 Speaker 1: products in the future and Uh, it's kind of a 466 00:27:15,880 --> 00:27:19,520 Speaker 1: neat idea. I would never have thought to do that. Um. 467 00:27:19,560 --> 00:27:22,480 Speaker 1: But then again, in n I might not have seen 468 00:27:23,080 --> 00:27:26,320 Speaker 1: use for a laser either. So I thought we might 469 00:27:26,400 --> 00:27:30,800 Speaker 1: also talk a little bit about potential hazards with lasers, 470 00:27:30,800 --> 00:27:33,040 Speaker 1: because here's the thing is that when you have this 471 00:27:33,160 --> 00:27:36,600 Speaker 1: intense beam of light, that's a lot of energy concentrated 472 00:27:36,640 --> 00:27:40,520 Speaker 1: into a relatively small space. Yes, and that energy can 473 00:27:40,560 --> 00:27:46,200 Speaker 1: sometimes be dangerous, yes, especially if it's particularly concentrated. So 474 00:27:46,280 --> 00:27:52,159 Speaker 1: there are different levels of laser classifications that UM that 475 00:27:52,280 --> 00:27:56,920 Speaker 1: will essentially will tell you like how dangerous they can be. Uh. 476 00:27:57,080 --> 00:28:00,600 Speaker 1: For example, a class one laser, Uh, they they aren't 477 00:28:00,600 --> 00:28:02,879 Speaker 1: really that hazardous at all, But it goes from class 478 00:28:02,920 --> 00:28:05,640 Speaker 1: one to class four. There's a couple of little sub 479 00:28:05,760 --> 00:28:07,800 Speaker 1: levels in there too, like there's a class you know, 480 00:28:09,000 --> 00:28:11,280 Speaker 1: there's like a class three M and that kind of thing. 481 00:28:11,800 --> 00:28:14,520 Speaker 1: But up to the class four laser, you're talking about 482 00:28:14,560 --> 00:28:17,639 Speaker 1: high powered lasers, which are dangerous to look at and 483 00:28:17,640 --> 00:28:20,719 Speaker 1: are also they can you know, create, they could they 484 00:28:20,720 --> 00:28:25,520 Speaker 1: could burn things they can, including you or other objects. Um. 485 00:28:25,560 --> 00:28:29,159 Speaker 1: And interestingly, a lot of this has to do with 486 00:28:29,200 --> 00:28:32,399 Speaker 1: the wavelength again, So lasers that have a wavelength between 487 00:28:32,400 --> 00:28:37,919 Speaker 1: around eighty to three and fifty nenometers can if you 488 00:28:37,960 --> 00:28:39,760 Speaker 1: were to get hit in the eyes with them, they 489 00:28:39,760 --> 00:28:43,840 Speaker 1: can actually create an inflammation of the cornea UM. And 490 00:28:43,880 --> 00:28:47,600 Speaker 1: then slightly higher than that, up to four nmeters you're 491 00:28:47,600 --> 00:28:52,600 Speaker 1: talking about possibly creating cataracts UM. And then higher than 492 00:28:52,600 --> 00:28:56,600 Speaker 1: that you're talking about retinal burn. Uh. And then uh 493 00:28:56,920 --> 00:28:59,040 Speaker 1: you're talking about corneal burn if you get a little 494 00:28:59,080 --> 00:29:02,080 Speaker 1: higher than that. I mean, it's dangerous stuff, especially around 495 00:29:02,120 --> 00:29:04,200 Speaker 1: the eyes. And that's part of the reason why you 496 00:29:04,240 --> 00:29:09,400 Speaker 1: may have heard stories about UM Pilots and airlines concerned 497 00:29:09,440 --> 00:29:13,560 Speaker 1: with the possibility of people shining lasers into the cockpits 498 00:29:13,640 --> 00:29:17,040 Speaker 1: of airplanes, and uh, then this is the thing. I mean, 499 00:29:17,040 --> 00:29:22,240 Speaker 1: there have been thousands of incidents reported of pilots uh 500 00:29:22,560 --> 00:29:26,719 Speaker 1: noticing that someone's trying to uh direct a laser into 501 00:29:26,800 --> 00:29:29,560 Speaker 1: the cockpit. It's not to burn the person necessarily, but 502 00:29:29,720 --> 00:29:34,280 Speaker 1: perhaps blind them or caused some other uh problem during 503 00:29:34,800 --> 00:29:37,320 Speaker 1: takeoff or landing, and those, of course are the most 504 00:29:37,360 --> 00:29:42,000 Speaker 1: critical times of an when an airplane is is traveling. 505 00:29:42,920 --> 00:29:46,480 Speaker 1: So uh, yeah, lasers are are I mean, they're kind 506 00:29:46,480 --> 00:29:48,960 Speaker 1: of cool to play with, but yes, when you hear 507 00:29:49,000 --> 00:29:51,520 Speaker 1: the warning don't shine this into your eye. Take that 508 00:29:52,040 --> 00:29:55,160 Speaker 1: to heart. Yeah, and don't shine it in anyone else's eye, right, Yeah, 509 00:29:55,240 --> 00:29:57,880 Speaker 1: don't shine it in any eyes. No eyes get get 510 00:29:57,920 --> 00:30:00,240 Speaker 1: shown in. Yeah. I have the feeling that lot of 511 00:30:00,240 --> 00:30:05,600 Speaker 1: people who are are trying to shine lasers into airplanes 512 00:30:05,640 --> 00:30:10,040 Speaker 1: are are just pooling around, um and aren't necessarily trying 513 00:30:10,080 --> 00:30:13,640 Speaker 1: to hurt anyone. But yeah, that's that's not a fun 514 00:30:13,640 --> 00:30:16,000 Speaker 1: prank to pull on someone. I should also say I 515 00:30:16,040 --> 00:30:18,840 Speaker 1: said three M, and that's not right. There is a 516 00:30:18,920 --> 00:30:22,959 Speaker 1: class three three R and three B. Oh, there's it's 517 00:30:23,000 --> 00:30:26,280 Speaker 1: an R and a B R. Yeah, because our article 518 00:30:26,480 --> 00:30:29,080 Speaker 1: is a little outdated, there's been a reclassification of the 519 00:30:29,120 --> 00:30:31,800 Speaker 1: laser system. So actually I need to go in and 520 00:30:32,000 --> 00:30:34,040 Speaker 1: update our article. I just noticed as I was looking, 521 00:30:34,040 --> 00:30:35,560 Speaker 1: I was like, wait a minute, I know that there 522 00:30:35,600 --> 00:30:38,760 Speaker 1: was a reclassification of the laser system. Uh. Yeah, there's 523 00:30:38,760 --> 00:30:42,000 Speaker 1: a class to M, but there's no three M. There's 524 00:30:42,040 --> 00:30:45,640 Speaker 1: three R and three B. But at any rate, Yeah, 525 00:30:45,880 --> 00:30:48,480 Speaker 1: the higher you go in general, the more dangerous the 526 00:30:48,520 --> 00:30:53,000 Speaker 1: laser is to your health and safety. Um. Now, we're 527 00:30:53,040 --> 00:30:55,760 Speaker 1: probably gonna find lots of other cool uses for lasers. 528 00:30:55,760 --> 00:30:59,920 Speaker 1: We've used lasers to do everything from uh, studying things 529 00:31:00,000 --> 00:31:02,560 Speaker 1: at the atomic level to studying things at the cosmic level. 530 00:31:03,160 --> 00:31:08,040 Speaker 1: So it's an incredibly useful tool. And it's really amazing 531 00:31:08,080 --> 00:31:11,560 Speaker 1: that Einstein was able to come up with essentially what 532 00:31:11,600 --> 00:31:15,240 Speaker 1: was the basis of what what all lasers work on? 533 00:31:15,480 --> 00:31:18,719 Speaker 1: Way back in in nineteen six And you know, there 534 00:31:18,800 --> 00:31:21,479 Speaker 1: was no way at the time, no real practical way 535 00:31:21,520 --> 00:31:26,280 Speaker 1: at the time to build anything that would prove that 536 00:31:26,520 --> 00:31:31,080 Speaker 1: his theory was correct. So it took several decades before 537 00:31:31,080 --> 00:31:33,000 Speaker 1: we were able to build something that actually said, hey, 538 00:31:33,040 --> 00:31:37,240 Speaker 1: you know what, he seems to know something about this. Well, 539 00:31:37,280 --> 00:31:39,320 Speaker 1: you know, he he was kind of ahead of his 540 00:31:39,400 --> 00:31:41,320 Speaker 1: time in a lot of ways. Well it's all relative. 541 00:31:42,600 --> 00:31:45,760 Speaker 1: H So that wraps up this discussion. If you do 542 00:31:45,800 --> 00:31:48,560 Speaker 1: want to learn more about lasers, we have several articles 543 00:31:48,560 --> 00:31:51,040 Speaker 1: on the site that relate to lasers and including how 544 00:31:51,160 --> 00:31:54,920 Speaker 1: lasers work, but also our articles on everything from CD 545 00:31:55,040 --> 00:31:58,320 Speaker 1: players which also use lasers, to DVD, Blu Ray, UM 546 00:31:58,440 --> 00:32:01,040 Speaker 1: and tons of other content. And it is a really 547 00:32:01,080 --> 00:32:04,880 Speaker 1: fascinating technology and I recommend looking into it if you've 548 00:32:04,880 --> 00:32:09,920 Speaker 1: ever been curious. UM. Also, there's the the amazing documentary 549 00:32:09,960 --> 00:32:15,160 Speaker 1: film real genius. There's a bunch of students making a laser. Okay, 550 00:32:15,200 --> 00:32:17,960 Speaker 1: that that's that's not a documentary. It's actually a comedy 551 00:32:18,000 --> 00:32:21,840 Speaker 1: from the Eight starring fel Kilmer. But yeah, I I 552 00:32:21,960 --> 00:32:25,600 Speaker 1: recommend all those things because that movie is hilarious. And 553 00:32:25,680 --> 00:32:28,280 Speaker 1: with that, we're gonna wrap up this discussion. If you 554 00:32:28,280 --> 00:32:30,040 Speaker 1: would like to tell us about how you plan to 555 00:32:30,120 --> 00:32:32,760 Speaker 1: use a laser to dominate the Earth or any other 556 00:32:32,960 --> 00:32:35,840 Speaker 1: sort of suggestions of topics that we can tackle, you 557 00:32:35,880 --> 00:32:38,600 Speaker 1: can let us know on Twitter or Facebook. Are handled 558 00:32:38,640 --> 00:32:42,280 Speaker 1: there is tech Stuff hs W, or you can email us. 559 00:32:42,320 --> 00:32:45,600 Speaker 1: That address is tech stuff at tell stuff works dot 560 00:32:45,600 --> 00:32:47,280 Speaker 1: com and Chris and I will talk to you again 561 00:32:48,000 --> 00:32:53,160 Speaker 1: really soon. Pu pu laser for Mora on this and 562 00:32:53,240 --> 00:32:55,880 Speaker 1: thousands of other topics. Is it how stuff works dot com. 563 00:32:56,120 --> 00:32:58,760 Speaker 1: So learn more about the podcast, click on the podcast 564 00:32:58,960 --> 00:33:02,520 Speaker 1: icon in the upper right corner of our homepage. The 565 00:33:02,560 --> 00:33:05,560 Speaker 1: House Stuff Works iPhone app has arrived. Download it today 566 00:33:05,800 --> 00:33:13,000 Speaker 1: on iTunes. Brought to you by the reinvented two thousand 567 00:33:13,080 --> 00:33:15,200 Speaker 1: twelve camera. It's ready, are you