WEBVTT - What Is Radiation? 0:00:06.920 --> 0:00:09.639 Hey, Daniel, what would you sacrifice for the sake of 0:00:09.720 --> 0:00:13.399 a big scientific discovery. Oh, that's a good question. I 0:00:13.400 --> 0:00:17.759 would give up something juicy. I don't know, weekends, evenings, maybe, 0:00:17.800 --> 0:00:19.920 like I don't know, a pinky toe. I'd probably give 0:00:20.000 --> 0:00:23.040 up a pinky toe. Really, you wouldn't sacrifice your life 0:00:23.120 --> 0:00:26.320 for science. You wouldn't risk your life for a big breakthrough. 0:00:26.640 --> 0:00:29.160 I would love to reveal something deep about the universe, 0:00:29.280 --> 0:00:31.360 but now I'd like to live to see it. You know, 0:00:31.400 --> 0:00:33.760 I don't think. I don't think scientific breakthroughs are worth 0:00:33.800 --> 0:00:36.680 sacrificing your life. Well, you know, some of my my history's 0:00:36.760 --> 0:00:40.559 most famous scientists, like Marie Cree, died to make their 0:00:40.600 --> 0:00:43.919 prize winning discoveries. That's true, and I'm pretty impressed. Though 0:00:43.960 --> 0:00:46.639 I wonder if she really understood, like in advance, how 0:00:46.760 --> 0:00:50.159 dangerous that research she was doing actually was. But let 0:00:50.200 --> 0:00:52.080 me turn the table on you. Are you willing to 0:00:52.159 --> 0:00:54.960 risk your life or something like a really tasty snack? 0:00:56.280 --> 0:01:00.920 How tasty are we talking about? We're talking and long 0:01:01.360 --> 0:01:04.720 yellow and comes naturally wrapped in its own um, in 0:01:04.760 --> 0:01:07.880 its own packaging. Oh man, our snacks deadly? Now what 0:01:07.920 --> 0:01:09.959 are you talking about? Well, I'm sorry to be the 0:01:09.959 --> 0:01:12.520 one to tell you, but there's something in common between 0:01:12.840 --> 0:01:18.080 Madame Curies research in your favorite snack. Have you heard 0:01:18.080 --> 0:01:21.280 the joke of what did Pierre Cree tell Mary Curry? Now, 0:01:21.319 --> 0:01:24.160 what did Pierre Curry tell Mary Cury? He said, my dear, 0:01:24.240 --> 0:01:30.640 you are positively glowing tonight. You look radiant, Oh man. 0:01:49.640 --> 0:01:52.320 I am Jorge. I'm a cartoonist and the creator of 0:01:52.440 --> 0:01:56.559 PhD Comics. I'm Daniel, I'm a particle physicist, and together 0:01:56.600 --> 0:01:58.680 were the authors of the book We Have No Idea 0:01:59.000 --> 0:02:01.920 and the host of this cast, Daniel and Jorge Explain 0:02:02.000 --> 0:02:05.080 the Universe, a production of I Heart Radio, in which 0:02:05.120 --> 0:02:07.480 we look at things in the universe that makes sense 0:02:07.600 --> 0:02:11.040 or don't make sense, or or are slightly confusing or 0:02:11.200 --> 0:02:13.440 very confusing, and break them down for you to make 0:02:13.440 --> 0:02:16.560 sure we understand what's actually going on. That's right, all 0:02:16.600 --> 0:02:19.600 the amazing things in the universe that will astound you 0:02:19.680 --> 0:02:23.640 and amaze you and possibly also kill you or save 0:02:23.760 --> 0:02:27.520 your life. Sometimes there are good sides to things that 0:02:27.720 --> 0:02:33.560 sound dangerous. Yeah, like bananas. Like bananas. Yes, bananas are 0:02:33.600 --> 0:02:36.880 a double edged snack, exactly as we'll get into on 0:02:36.919 --> 0:02:39.760 this podcast. You mean like you eat them and they're delicious, 0:02:39.760 --> 0:02:43.560 But then the peel you can slip on and die. Well, 0:02:43.600 --> 0:02:45.760 I assume that you're always wearing you know, safety gear 0:02:45.760 --> 0:02:50.840 when you eat a banana, right, banana slipproof shoes. No, 0:02:50.960 --> 0:02:52.640 I'm talking about a helmet. If you have a helmet home, 0:02:52.720 --> 0:02:54.360 you eat a banana, then you know it's no big deal. 0:02:55.440 --> 0:02:59.720 I see, I seem to be On the podcast. We're 0:02:59.800 --> 0:03:03.119 tag playing a subject that a couple of people asks online, 0:03:03.480 --> 0:03:05.320 but which is kind of a big deal. It's in 0:03:05.480 --> 0:03:08.200 our everyday lives. We use it all the time, and 0:03:08.280 --> 0:03:12.079 it can be both dangerous and can also save your 0:03:12.120 --> 0:03:14.000 life at the same time. It's something you hear about 0:03:14.000 --> 0:03:16.799 a lot in science and science fiction. It's something that's 0:03:16.919 --> 0:03:20.440 vaguely mysterious, and I think has suffered from a bad 0:03:20.480 --> 0:03:23.880 PR campaign. It definitely, I think is associated with something bad. 0:03:24.200 --> 0:03:26.160 But as we want to show you in today's podcast, 0:03:26.240 --> 0:03:29.600 there's two sides to every particle. So today on the podcast, 0:03:29.600 --> 0:03:37.400 we'll be talking about radiation. Is it good for you? 0:03:37.520 --> 0:03:41.560 Is it bad for you? Spicy? Mild? What is radiation anyway? 0:03:41.880 --> 0:03:46.280 Is it fizzle when you eat it tastes like bananas? Right? 0:03:46.360 --> 0:03:48.400 Is it that are those cans that put on your tongue, 0:03:48.440 --> 0:03:51.360 Are those actually radioactive? Right? No? I think you're right. 0:03:51.360 --> 0:03:54.400 I think radiation sort of has a bad name in society, right, 0:03:54.440 --> 0:03:57.640 Like nobody thinks radiation and things. Oh, I could use 0:03:57.640 --> 0:04:01.960 some of that, thanks, Actually, where do I get some? Yeah? 0:04:01.960 --> 0:04:04.720 It definitely is a boogeyman, right, It's definitely something that 0:04:04.960 --> 0:04:07.920 people are afraid of. And I think the roots of 0:04:07.960 --> 0:04:11.120 it are are that it's something that's sort of recently discovered, 0:04:11.160 --> 0:04:14.080 you know, like our ancestors had no idea about radiation. 0:04:14.440 --> 0:04:18.400 It's something that it's a product of modern science. Yeah, 0:04:18.480 --> 0:04:23.360 I mean it was sort of discovered not too long ago, right, 0:04:23.640 --> 0:04:26.120 maybe a hundred years Yeah, exactly. So around the turn 0:04:26.120 --> 0:04:28.880 of the century, like eight late eighteen hundreds, people started 0:04:28.880 --> 0:04:32.200 to discover X rays and cathude rays and all sorts 0:04:32.200 --> 0:04:34.000 of other kind of rays, and they didn't really know 0:04:34.040 --> 0:04:36.039 what it was. It was this new mysterious thing. It 0:04:36.120 --> 0:04:39.680 was invisible. It could develop photographs, you could you could 0:04:39.680 --> 0:04:42.840 see it on photographic film. Um. Later they discovered it 0:04:42.920 --> 0:04:45.800 could kill you, right, Um, it could you could use 0:04:45.800 --> 0:04:48.120 it to like take pictures of the inside of the body. 0:04:48.240 --> 0:04:52.200 It was mysterious and weird. Um and so it's kind 0:04:52.240 --> 0:04:54.360 of new, it's kind of it's powerful, right, it kind 0:04:54.360 --> 0:04:58.360 of violates our everyday intuition. Yeah, exactly. And I think 0:04:58.720 --> 0:05:01.919 that's part of the the scariness of it is that 0:05:01.960 --> 0:05:04.120 it shows us that the world is different from what 0:05:04.160 --> 0:05:09.040 we understood, and that there's this untapped power, this untapped potential, 0:05:09.320 --> 0:05:12.760 which could be terribly dangerous. Right. For me, radiation is 0:05:12.800 --> 0:05:16.239 like the classic Frankenstein thing, like shows us that science 0:05:16.240 --> 0:05:18.760 has cracked open a whole new world. And it could 0:05:18.800 --> 0:05:20.720 go either way. Right, you could help you, or it 0:05:20.720 --> 0:05:22.880 could hurt you if you don't understand what what what 0:05:23.000 --> 0:05:25.880 you're doing, it could lead to dangerous side effects. Yeah. 0:05:26.000 --> 0:05:29.040 I feel like it's also cracked open the world of superheroes. 0:05:29.640 --> 0:05:32.560 You know, without radiation, you wouldn't have Spider Man, you 0:05:32.600 --> 0:05:35.719 wouldn't have the Hulk, you wouldn't have Captain America. Yeah. 0:05:35.800 --> 0:05:37.680 But I think that that just reflects that, right. I 0:05:37.680 --> 0:05:40.560 think what you see in comic books are like reflect 0:05:40.760 --> 0:05:43.480 what the what the population is thinking about, what they 0:05:43.520 --> 0:05:46.920 are afraid of, right, which is why radiation played such 0:05:46.920 --> 0:05:48.920 a big role, you know, Spider Man, as you said, 0:05:48.920 --> 0:05:51.440 and Bruce banner and all that stuff, and these days 0:05:51.480 --> 0:05:53.200 it's more like you see a lot of ai kind 0:05:53.200 --> 0:05:55.599 of stuff in comic books, like the villain is some 0:05:55.880 --> 0:05:58.840 computer that's taking over the world or something. And so 0:05:59.120 --> 0:06:02.520 maybe radiation had its day as the as a scientific villain. 0:06:02.800 --> 0:06:05.200 But like you were saying, in society, we still think 0:06:05.200 --> 0:06:08.279 of it as as bad, right, Like nobody, um wants 0:06:08.279 --> 0:06:10.240 to get any of that radiation, That's right. I think 0:06:10.240 --> 0:06:13.599 if you say radiation, people think cancer, or they think 0:06:13.960 --> 0:06:18.080 nuclear bombs, or you know, evil scientists and lab coats 0:06:18.160 --> 0:06:21.919 cackling maniacally, right, not good things. But we're wondering, do 0:06:21.960 --> 0:06:26.360 you think people really understand radiation? Like do they know 0:06:26.400 --> 0:06:28.880 what it is, what it means? And is it all 0:06:28.920 --> 0:06:31.480 that bad? All? Right? Where it comes from? Right? How 0:06:31.480 --> 0:06:33.919 to make it? How to avoid it? Um? Are you 0:06:33.920 --> 0:06:36.840 getting some right now? Yeah? So we were wondering too 0:06:36.880 --> 0:06:41.160 people have understanding. The answer is yes, you are being 0:06:41.240 --> 0:06:45.800 radiated um right now. You listen to this podcast, right, 0:06:45.800 --> 0:06:48.480 and so you're listening, you're getting sonic radiation right now. 0:06:49.000 --> 0:06:51.479 But I'm not just from our the brilliance of our 0:06:51.480 --> 0:06:55.640 thoughts and words, but you are literally right now bathed 0:06:55.720 --> 0:06:59.440 in radiation. Probably unless you're in a lead box somewhere, 0:06:59.440 --> 0:07:03.880 in which case you probably have other problems. Then we 0:07:03.920 --> 0:07:05.840 have to ask, yeah, what are you doing in that 0:07:05.920 --> 0:07:08.560 lead box? What did you to deserve it? Right, it's 0:07:08.600 --> 0:07:11.800 probably your fault. Yeah, Well, as usual, we got curious, 0:07:11.840 --> 0:07:14.440 and so Daniel went out into the street as people 0:07:14.800 --> 0:07:18.360 random people on the street. What is radiation? That's right? 0:07:18.400 --> 0:07:20.480 And here's what people had to say. How would you 0:07:20.520 --> 0:07:24.040 define or describe radiation? What is radiation? The one form 0:07:24.040 --> 0:07:28.320 of radiation I know is like extray. They emit radiation. 0:07:28.480 --> 0:07:30.320 I know there are other forms also, Yeah, there's like 0:07:30.600 --> 0:07:34.360 EUV and other times. All right, cool, thanks very much. 0:07:34.440 --> 0:07:38.160 What is radiation? Um, it's some kind of like some 0:07:38.240 --> 0:07:41.120 kind of force or like chemical kind of that can 0:07:41.440 --> 0:07:44.600 like go through things like an experience, Like there's radiation. 0:07:44.680 --> 0:07:48.840 M R. There's radiations and it goes through things. Well, 0:07:49.240 --> 0:07:52.640 radiation is bad, I think if you absorb it. But 0:07:52.760 --> 0:07:55.880 isn't radiation just like the splitting off of like the 0:07:56.000 --> 0:07:58.840 breaking a part of like particles and atoms, And so 0:08:00.280 --> 0:08:03.680 they become like like isn't that kind of like related 0:08:03.680 --> 0:08:06.080 to free radicals or something? And what is radiation? A 0:08:06.080 --> 0:08:09.960 little bit about it? About radiation, but specifically UV radiation, 0:08:10.000 --> 0:08:13.720 which causes diamondine dimers, which is obviously cause of skin cancer. 0:08:14.280 --> 0:08:16.400 So that's a major concern. But then you have the 0:08:16.400 --> 0:08:21.239 ozone layer, which can block some harmful radiation is photon. 0:08:21.360 --> 0:08:25.600 So nope, well I don't know, like it like gives 0:08:25.640 --> 0:08:27.360 off like I don't know, it comes from somewhere, but 0:08:27.400 --> 0:08:29.800 like give you cancer and stuff like I don't know. 0:08:29.920 --> 0:08:31.120 Do you know what it's made out of? Like what 0:08:32.080 --> 0:08:33.920 you know? I don't know what it's made out of? Cool? 0:08:34.679 --> 0:08:37.080 What is radiation? I don't know. I think that makes 0:08:37.120 --> 0:08:42.400 superheroes or something. I don't know. I don't know. It's bad, 0:08:42.640 --> 0:08:46.080 it's bad, Okay, alright, great, alright, So I like the 0:08:46.080 --> 0:08:48.479 person who said that it's the thing that makes superheroes. 0:08:48.640 --> 0:08:53.280 I was like, yes, something, here's something good about radiation. 0:08:53.320 --> 0:08:55.920 It gives these superheroes exactly. I mean, that's what we 0:08:55.960 --> 0:08:57.199 should do. We should just like take a bunch of 0:08:57.240 --> 0:09:00.680 our soldiers and radiatum and see what happens. Yeah, no, 0:09:00.800 --> 0:09:06.440 let's not do that. What could go What could go wrong? Right? Yeah, 0:09:06.440 --> 0:09:08.520 what could go wrong? But a lot of people just 0:09:08.600 --> 0:09:11.719 kind of immediately went with that it's something bad. It's 0:09:11.760 --> 0:09:16.520 not good, definitely bad. Right, radiation, Big Radiations lobbying firm 0:09:16.600 --> 0:09:18.800 has a lot of work to do on changing the 0:09:18.840 --> 0:09:22.959 public perception of radiation. Oh man, I wouldn't want that job. 0:09:23.400 --> 0:09:26.320 I work for Big Radiation. You know. What they need 0:09:26.360 --> 0:09:29.040 to do is come up with like a cute anthropomorphic 0:09:29.160 --> 0:09:32.360 character for radiation and have, you know, smile and bounce 0:09:32.400 --> 0:09:34.040 around and the scream with a little Diddy playing in 0:09:34.040 --> 0:09:39.280 the background, like a cute little cancer seal or something exactly, 0:09:38.679 --> 0:09:42.280 a cute little wave or a cute little particle. Maybe Hi, 0:09:42.960 --> 0:09:45.280 I'm a proton. I'm here to help to give you 0:09:45.320 --> 0:09:49.240 cancer treatments, right, m I don't know. But but a 0:09:49.280 --> 0:09:50.680 lot of people just kind of had the idea that 0:09:50.679 --> 0:09:53.360 it's some sort of energy, some something that moves the 0:09:53.480 --> 0:09:57.520 propagates and goes through things. Right, that's yeah, yeah, yeah. 0:09:57.559 --> 0:09:58.839 A lot of people were on the right track. A 0:09:58.840 --> 0:10:00.240 lot of people are on the right track. Faith thought 0:10:00.240 --> 0:10:02.200 it was bad. Some people didn't really know. So people 0:10:02.240 --> 0:10:05.880 listed an example of radiation, right, which is good, totally solid. 0:10:06.200 --> 0:10:10.080 I'd give them a solid it be on that answer. Um. 0:10:10.120 --> 0:10:13.280 And one of the guys whom I asked is actually 0:10:13.280 --> 0:10:17.160 a physics professor in my department costed on the street 0:10:17.400 --> 0:10:19.679 to ask him this question, and I gave a pretty 0:10:19.679 --> 0:10:21.960 good answer on the spot. So, um, I think we 0:10:21.960 --> 0:10:25.440 can we can break it down for people. What is radiation? Yeah, 0:10:25.480 --> 0:10:32.439 break it down from Dana, what is radiation? Radiation most 0:10:32.480 --> 0:10:35.120 generally can either be a particle or wave, but it's 0:10:35.160 --> 0:10:39.240 basically just energy moving through space, right, So it can 0:10:39.280 --> 0:10:42.840 be like photons, right, Like light is radiation. You know, 0:10:42.960 --> 0:10:46.720 all kinds of light, from radio waves to visible light, 0:10:46.840 --> 0:10:49.560 to X rays, to ultra violet light, to gamma rays 0:10:49.600 --> 0:10:51.760 that we talked about in a previous podcast, those are 0:10:51.760 --> 0:10:55.720 all examples of radiation. So basically light, you're saying. But 0:10:55.880 --> 0:10:59.400 like we covered in a previous podcast, light of different 0:10:59.400 --> 0:11:03.200 frequency have different names, but it's basically basically all this light. 0:11:03.559 --> 0:11:06.480 It's all. Yeah, there's lots of different kinds of light, right, 0:11:06.480 --> 0:11:08.640 which which comes because they have different they wiggle at 0:11:08.640 --> 0:11:11.800 different speeds, right, wiggle really really fast, the gamma rays 0:11:11.840 --> 0:11:14.120 that wiggle really really slow, their radio waves that wiggle 0:11:14.400 --> 0:11:17.720 in the middle of their visible light, and all light 0:11:17.840 --> 0:11:20.640 is radiation because it's energy moving through space, right, Like 0:11:20.679 --> 0:11:23.040 when the sun makes light and shines it on the earth. 0:11:23.480 --> 0:11:26.400 It's irradiating the earth. So next time you go out 0:11:26.440 --> 0:11:30.160 and like enjoy the sun's warmth, you are like absorbing 0:11:30.320 --> 0:11:33.920 radiation from the sun. Right, And so every photon you absorb, 0:11:34.000 --> 0:11:37.160 every photon that hits your eye technically is radiation, but 0:11:37.240 --> 0:11:40.160 it's not a particular frequency range where it's not a 0:11:40.160 --> 0:11:43.080 particular type of light. Like all light is considered radiation, 0:11:43.120 --> 0:11:45.480 Like the the light bulb in here in my house, 0:11:45.520 --> 0:11:48.720 in my room, that that that is emitting radiation that 0:11:48.760 --> 0:11:51.480 I'm receiving and I'm using it to see that's right. 0:11:51.559 --> 0:11:53.679 And here again we run into the same problem that 0:11:53.720 --> 0:11:55.679 we run into like all the time in this podcast, 0:11:55.720 --> 0:11:59.960 where we have a name that people use in language, radiation, 0:12:00.000 --> 0:12:02.839 and then we have the physics term, right, which is 0:12:02.840 --> 0:12:07.240 a technical definition, so the technical definition, and like in science, 0:12:07.760 --> 0:12:11.040 all light is radiation. Practically, when we you know, colloquially, 0:12:11.040 --> 0:12:14.400 when we talk about radiation, what we mean is damaging radiation, 0:12:14.520 --> 0:12:19.360 radiation that can hurt you, right, But technically light is radiation, right, 0:12:19.440 --> 0:12:22.120 all light, visible lights from the life of the photons 0:12:22.160 --> 0:12:24.880 in your room is also radiation. That's probably not what 0:12:24.920 --> 0:12:28.400 people mean when they say radiation, but technically it's true. 0:12:28.600 --> 0:12:30.400 And you know there are other things that are also radiation, 0:12:30.440 --> 0:12:34.800 like sound. Sound waves is radiation. It's acoustic radiation. Right. 0:12:35.320 --> 0:12:38.480 So I'm talking to my microphone, I'm irradiating this microphone, 0:12:38.800 --> 0:12:41.320 and then I'm irradiating your ears and you listener are 0:12:41.360 --> 0:12:45.280 being irradiated by our sonic vibrations right now. Wow. Okay, 0:12:45.280 --> 0:12:48.400 so that you're saying to physics technical definition, it's really 0:12:48.400 --> 0:12:52.360 just anything that moves and propagates through space. Yeah, anything 0:12:52.400 --> 0:12:55.320 that transfers energy. It can be particles, it can be waves. 0:12:55.400 --> 0:12:58.600 Some things are particles slash waves slash weird quantum mechanical things. 0:12:58.600 --> 0:13:01.720 We don't really understand. All that stuff is radiation. So 0:13:01.760 --> 0:13:06.000 that includes you know, protons and electrons and neutrons and 0:13:06.240 --> 0:13:10.000 alpha particles which are just helium nuclei. It even includes 0:13:10.080 --> 0:13:13.800 things like gravitational radiation, right, like gravitational waves that were 0:13:13.840 --> 0:13:17.320 detected recently by Ligo, that big interfrometer that saw the 0:13:17.440 --> 0:13:20.560 ripples in space and time when black holes collided. That's 0:13:20.679 --> 0:13:24.280 radiation also. So basically you're saying that anything that moves 0:13:24.480 --> 0:13:27.320 is radiation. It doesn't matter if it has energy, if 0:13:27.320 --> 0:13:32.400 he has no mass, anything that moves through space is radiation. Like, yeah, 0:13:32.640 --> 0:13:35.960 me walking down the hall, I'm radiating down the hall. 0:13:38.600 --> 0:13:40.600 You know, I never thought of that, but yeah, you 0:13:40.640 --> 0:13:44.880 are radiation, that's true. I am a peper here, Danny. 0:13:46.600 --> 0:13:49.080 So radiation can't be all bad, right because it includes 0:13:49.120 --> 0:13:52.640 people nice people like you. So there you go, there 0:13:52.640 --> 0:13:56.680 you go, case closed, case closed. Radiation is not all bad. Um. Yeah. 0:13:56.720 --> 0:13:59.760 But so from a technical point of view, radiation is everywhere. 0:14:00.000 --> 0:14:02.880 It is. It's all around us. Um. And you know 0:14:02.920 --> 0:14:06.080 sound is radiation, light is radiation, all this kind of stuff. Um. 0:14:06.080 --> 0:14:08.800 One person said, you know radiation is a chemical or 0:14:08.800 --> 0:14:11.880 it's a force, right, It's not. It's not really a 0:14:11.960 --> 0:14:16.439 chemical or force. Um. People do get treatment for cancer 0:14:16.559 --> 0:14:19.640 that's called chemotherapy, and some people think that involves radiation. 0:14:19.880 --> 0:14:23.920 It doesn't involves chemicals, which is it's called chemotherapy. Um. 0:14:24.000 --> 0:14:26.120 So radiation is not like a chemical you inject in 0:14:26.160 --> 0:14:29.480 your body. It's not a force. It's not like gravity 0:14:29.680 --> 0:14:33.240 or the electromagnetism or whatever. But though some of the 0:14:33.280 --> 0:14:37.240 particles that transmit those forces, like photons, are radiation, so 0:14:37.280 --> 0:14:39.600 it's not like its own force or its own chemical. 0:14:40.440 --> 0:14:42.960 So there are things that are not radiation. It's not 0:14:43.280 --> 0:14:46.240 everything not radiation. Yeah, there are things that are not radiation. Yeah. 0:14:46.240 --> 0:14:48.440 And and actually we live in a time in the 0:14:48.520 --> 0:14:53.360 universe when there isn't very much radiation. What. Yeah, if 0:14:53.400 --> 0:14:55.240 you look at the history of the universe, like the 0:14:55.400 --> 0:14:59.440 really long scale history of the universe, the very early universe, 0:14:59.680 --> 0:15:02.920 there was a huge amount of radiation. Like if you say, 0:15:03.200 --> 0:15:05.680 take all the energy in the universe, right, what is 0:15:05.760 --> 0:15:08.640 what's in the universe that has energy? Well, there's matter, right, 0:15:08.920 --> 0:15:12.720 matter has energy, there's radiation, radiation has energy, right, and 0:15:12.800 --> 0:15:16.400 there's things like dark energy, mysterious forces that are expanding 0:15:16.400 --> 0:15:19.640 the universe we don't understand. Well, the interesting thing is 0:15:19.680 --> 0:15:22.600 that through the history of the universe, different slices of 0:15:22.640 --> 0:15:26.400 that pie have been dominant. So in the very early universe, 0:15:26.640 --> 0:15:28.440 most of the energy in the universe was in a 0:15:28.560 --> 0:15:32.440 radiation like big bang, huge explosion. Mostly it's just a 0:15:32.480 --> 0:15:37.480 bunch of photons. Oh, I see. But then something changed, yeah, exactly, 0:15:37.480 --> 0:15:41.040 some of that energy to transformed into something else has right, 0:15:41.120 --> 0:15:43.480 A lot of that energy is transformed into matter, right, 0:15:43.840 --> 0:15:46.480 And the universe spread out and cooled, right, and a 0:15:46.520 --> 0:15:49.080 lot of those photons were absorbed, right, they were sucked 0:15:49.160 --> 0:15:52.200 up by matter um which is no longer ionized like 0:15:52.280 --> 0:15:55.640 formed atoms, and those atoms could absorb photons. So for 0:15:55.840 --> 0:15:58.160 in the very first period of the universe, or like 0:15:58.200 --> 0:16:01.200 the first um sixty years or so, the universe was 0:16:01.320 --> 0:16:04.320 radiation dominated. Most of the energy in the universe is radiation. 0:16:04.920 --> 0:16:08.120 Then for billions of years it was matter dominated, like 0:16:08.200 --> 0:16:10.000 most of the energy and the universe was stored in 0:16:10.160 --> 0:16:13.280 matter um, and radiation was a smaller piece of the pie. 0:16:13.800 --> 0:16:16.120 And then for the last five billion years or so, 0:16:16.560 --> 0:16:20.400 those got outstripped by dark energy, this new mysterious thing 0:16:20.880 --> 0:16:24.360 which is expanding the universe and now eats seventy of 0:16:24.400 --> 0:16:26.840 the whole pie, the energy budge of the universe. Now 0:16:26.880 --> 0:16:30.240 we live in a dark energy dominated universe. Wow, so 0:16:30.280 --> 0:16:33.040 weird to think the universe is changing, you know, like 0:16:33.120 --> 0:16:36.680 it's it's a composition, what it's made out of is 0:16:36.680 --> 0:16:39.200 not constant. He sounds like somebody talking about your niece 0:16:39.240 --> 0:16:41.440 or nephew. You're like, you got so big, I can't 0:16:41.440 --> 0:16:45.320 believe you, Like, whoa, how did you get so so harry? 0:16:45.480 --> 0:16:49.160 What exactly used to be all radiation? And now you 0:16:49.280 --> 0:16:53.800 got these energy Now you're this emailed team I don't 0:16:53.800 --> 0:16:57.520 get it. Yeah, the universe is evolving and we don't know, 0:16:57.560 --> 0:17:00.240 like what's the next epoch of the universe, Right, Is 0:17:00.320 --> 0:17:02.520 dark energy going to go away? Is something else going 0:17:02.560 --> 0:17:05.720 to turn on and swamp dark energy? Radiation is gonna 0:17:05.720 --> 0:17:08.199 come roaring back? Or you know who knows? Right? But 0:17:08.440 --> 0:17:09.800 I like, I like sort of how you said that. 0:17:10.080 --> 0:17:13.000 There's sort of the official physics definition of radiation, and 0:17:13.000 --> 0:17:17.240 then there's the kind of cultural societal definition of radiation yea, 0:17:17.680 --> 0:17:22.760 which is kind of specifically which specifically means something that 0:17:23.440 --> 0:17:30.760 energy that's somehow causes damage or effects your bodily functions 0:17:30.880 --> 0:17:34.960 or your your cellular the things in your body. Yeah, exactly, 0:17:35.240 --> 0:17:37.520 you can think of damaging radiation. It's sort of like 0:17:37.760 --> 0:17:41.960 really fast, super tiny little bullets. Each one can cause 0:17:42.040 --> 0:17:44.520 a tiny little bit of damage. And I think that's 0:17:44.520 --> 0:17:46.159 the kind of radiation people are most interested in. So 0:17:46.200 --> 0:17:48.840 let's focus on that for a minute, right. And there's 0:17:48.880 --> 0:17:51.719 kind of there's different kinds of radiation that can damage you, right. 0:17:51.760 --> 0:17:55.119 So for example, gamma rays, these are just high energy photons, 0:17:55.520 --> 0:17:58.280 but they have enough energy that they can penetrate through 0:17:58.280 --> 0:18:01.600 your skin and they can eye eyes. Ionizing means that 0:18:01.960 --> 0:18:04.879 it deposits enough energy on the electron in an atom 0:18:04.920 --> 0:18:08.359 that the electron it like escapes, right, It's like gets 0:18:08.520 --> 0:18:10.840 escape velocity, and so it can fly off and the 0:18:11.359 --> 0:18:14.240 atom then becomes an ion. And that's bad. It changes 0:18:14.240 --> 0:18:17.160 the chemistry that's happening inside your body, and it can 0:18:17.240 --> 0:18:20.280 change your DNA and can cause mutations and all sorts 0:18:20.280 --> 0:18:23.240 of stuff. But wait, what about regular light, like from 0:18:23.240 --> 0:18:26.160 a light buelb. Why isn't that Why doesn't that one 0:18:26.600 --> 0:18:29.080 cause any damage? Because it's absorbed by your skin. It 0:18:29.119 --> 0:18:32.040 doesn't have enough energy to penetrate your skin. The higher 0:18:32.240 --> 0:18:34.960 the frequency, the higher the energy. So gamma rays have 0:18:35.040 --> 0:18:39.439 more energy than normal visible light. Normal visible light, you know, 0:18:39.880 --> 0:18:42.000 stopped by your skin. That's why your skin, that's why 0:18:42.040 --> 0:18:44.520 your body is not transparent, right because light can't pass 0:18:44.560 --> 0:18:46.920 through it. That's why you're not invisible. If light could 0:18:46.920 --> 0:18:49.480 pass through you, you would be invisible that you know of. 0:18:52.680 --> 0:18:54.959 But what do I mean that doesn't emit enough energy 0:18:55.040 --> 0:18:58.040 like it it gets to the cells in my skin 0:18:58.840 --> 0:19:02.800 and it doesn't another energy to puncture through to wiggle around. 0:19:02.960 --> 0:19:05.840 What does that mean? Yeah, it's absorbed by the energy 0:19:05.960 --> 0:19:08.399 by the very outer layer of your skin, which is 0:19:08.440 --> 0:19:11.400 basically dead cells, right, and so it doesn't penetrate into 0:19:11.400 --> 0:19:16.840 anything important, whereas ultra violet light and gamma rays, those 0:19:16.880 --> 0:19:18.399 are the things that give you cancer and the reason 0:19:18.440 --> 0:19:21.080 they give you cancers because they go deeper into your skin. 0:19:21.680 --> 0:19:23.960 And so the way to protect yourself is like be 0:19:24.080 --> 0:19:27.000 inside because then the house absorbs the energy of the 0:19:27.000 --> 0:19:30.600 gamma rays or the UV light or wear sunscreen, right, 0:19:30.640 --> 0:19:32.520 because that has things in it that are good at 0:19:32.560 --> 0:19:37.320 absorbing um those kind of that frequency photon. So it's 0:19:37.359 --> 0:19:39.640 not it's not a it's is it an energy thing 0:19:39.760 --> 0:19:41.760 or like a frequency thing? You know, Like we had 0:19:41.800 --> 0:19:44.919 an episode about why is the sky blue and you 0:19:44.960 --> 0:19:49.000 said that the light it's because blue light is at 0:19:49.040 --> 0:19:52.040 the right sort of wavelength of that of the size 0:19:52.080 --> 0:19:55.719 of the molecules in the atmosphere, Is it something like 0:19:55.720 --> 0:19:57.760 that or is it just just energy, Just it just 0:19:57.880 --> 0:20:00.800 barrels through. It's just energy. Yeah, Just think of the 0:20:00.840 --> 0:20:05.159 body is like a bag of water, right, and it 0:20:05.200 --> 0:20:08.159 eventually gets slowed down and absorbed, and it's just a 0:20:08.240 --> 0:20:10.520 question of how deep into the body it gets. And 0:20:10.560 --> 0:20:12.920 so if it if it stops at the outermost layer 0:20:12.920 --> 0:20:15.160 where it's all just dead skin, then it doesn't really 0:20:15.200 --> 0:20:17.560 do any damage. Or you know, it gets stopped by 0:20:17.560 --> 0:20:21.240 your clothing, right, like visible like gets stopped by your clothing. Um, 0:20:21.240 --> 0:20:22.800 but if it gets into that bag of water and 0:20:22.800 --> 0:20:25.600 penetrates and you know, can ionize something important, then yet 0:20:25.640 --> 0:20:27.840 it can cause cancer. Well, it's interesting to me that 0:20:27.880 --> 0:20:31.320 it's not just like like gamma rays and X rays. 0:20:31.359 --> 0:20:36.600 It's also like radiation harmful. Radiation can be also like protons, right, 0:20:36.680 --> 0:20:39.880 and which is what I'm made out of and you're 0:20:39.920 --> 0:20:41.719 made out of. Like the things we're made out of 0:20:41.840 --> 0:20:44.879 can also be radioactive and and not good for you, 0:20:45.080 --> 0:20:47.359 that's right. And so like as we said before, like 0:20:47.359 --> 0:20:49.080 a proton can be good or bad. It can be 0:20:49.119 --> 0:20:52.159 part of a tasty snack, or it can come bringing cancer. 0:20:52.480 --> 0:20:55.720 And the only difference is that is whether it has energy. 0:20:55.840 --> 0:20:58.080 Like if I shoot a proton at you, and I 0:20:58.080 --> 0:21:00.119 could deposit a lot of energy in a part of 0:21:00.160 --> 0:21:02.199 your body, that's bad. Right, Think of a proton, it's 0:21:02.200 --> 0:21:04.240 like a tiny bullet. I mean, I could hand you 0:21:04.280 --> 0:21:05.760 a bullet. It's not going to kill you, right. A 0:21:05.760 --> 0:21:08.159 bullet by itself doesn't kill you. If I shoot a 0:21:08.160 --> 0:21:11.000 bullet at you really really fast, right, then it's gonna 0:21:11.040 --> 0:21:13.280 hurt you. Right, it's gonna deposit all of its energy 0:21:13.800 --> 0:21:15.399 in your body. It's gonna tear a hole in you. 0:21:15.960 --> 0:21:19.600 So it's the energy that that particle has that's the problem, right, 0:21:19.680 --> 0:21:22.480 not the particle itself. You're saying, bullets don't kill people. 0:21:23.400 --> 0:21:31.280 It's the protons. Kinetic energy kills people. Bullets people don't 0:21:31.359 --> 0:21:37.080 kill people. Physics stuff. Technically that's true. Oh man, oh man, 0:21:37.160 --> 0:21:39.680 I'm gonna be in trouble with the physics community after 0:21:39.760 --> 0:21:46.879 that comes out. You can deposit kinetic energy on somebody 0:21:46.920 --> 0:21:48.560 with lots of things, right. You could use a brick, 0:21:48.720 --> 0:21:50.720 you can use a bullet, you can use a rock like, 0:21:51.040 --> 0:21:53.000 you could even use a banana. I guess I don't know. 0:21:53.520 --> 0:21:56.280 But the thing that kills somebody is the kinetic energy transfer. Right, 0:21:56.320 --> 0:21:58.600 you hit somebody with a car, right, doesn't have to 0:21:58.640 --> 0:22:00.960 be a small thing. You deposit a lot of kinetic 0:22:01.000 --> 0:22:03.480 energy on somebody, you're going to hurt them. Now, proton 0:22:03.680 --> 0:22:06.400 is basically just a super tiny bullet. And so if 0:22:06.440 --> 0:22:09.160