WEBVTT - What is the cosmic microwave background? 0:00:08.880 --> 0:00:11.680 Crystal, did you know that the secrets of the universe 0:00:11.880 --> 0:00:16.600 are all around us? What? Where? No? I mean answers 0:00:16.600 --> 0:00:19.200 to some of the deepest questions in science are literally 0:00:19.560 --> 0:00:23.000 all around us, like hiding under my bed or what 0:00:23.040 --> 0:00:25.279 do you mean? Yeah, they're under your bed, but they're 0:00:25.280 --> 0:00:27.840 also just right here in the air between me and you. 0:00:28.440 --> 0:00:31.200 I guess Bob Dylan was right. What do you mean, 0:00:31.280 --> 0:00:34.680 Bob Dylan? They're all just blowing in the wind. I 0:00:34.720 --> 0:00:37.360 guess Bob Dylan was a poet and also secretly a 0:00:37.360 --> 0:00:41.360 physicist and a philosopher, Which aren't We are doctors a 0:00:41.400 --> 0:00:44.560 philosophy anyway. That's right. That doesn't mean we know anything 0:00:44.600 --> 0:01:03.440 about it, but we have the title. Hi. I'm Daniel. 0:01:03.480 --> 0:01:06.680 I'm a particle physicist and co host of the podcast 0:01:06.880 --> 0:01:10.680 Daniel and Jorgey Explain the Universe, brought to you by 0:01:10.800 --> 0:01:14.600 I Heart Review. My co host, the hilarious and good 0:01:14.600 --> 0:01:17.480 looking Jorge Cham is not here today to join us 0:01:17.560 --> 0:01:20.840 with his amazing jokes about bananas. He does love a 0:01:20.880 --> 0:01:24.840 good banana, He does love a good banana. But instead 0:01:24.880 --> 0:01:28.880 today we have a wonderful, amazing co host, Crystal Dilworth. Crystal, 0:01:28.920 --> 0:01:33.959 introduce yourself. Hello. I'm Dr Crystal Dilworth. I'm a neuroscientist, 0:01:34.400 --> 0:01:38.560 um my PhD s and molecular neuroscience, so the molecular 0:01:38.560 --> 0:01:42.000 basis of nicotine dependence from cal Tex. So I'm just 0:01:42.120 --> 0:01:45.279 a curious person that loves science communication and I'm super 0:01:45.360 --> 0:01:47.720 excited to be here to talk to you today. All right, well, 0:01:47.760 --> 0:01:50.600 thanks for joining us. So you studied nicotine addiction. Does 0:01:50.640 --> 0:01:53.280 that make you um in the pocket for big tobacco? 0:01:53.680 --> 0:01:57.520 It's a classic dilemma, right do you accept research funding 0:01:57.640 --> 0:02:01.680 from big tobacco? Um? I was supported by ni H, 0:02:01.760 --> 0:02:06.160 so I escaped that quandary, so you stayed clean. In 0:02:06.240 --> 0:02:08.239 my field, it's always a question of do you take 0:02:08.280 --> 0:02:11.799 money for weapons researchis you know, like my parents, for example, 0:02:11.800 --> 0:02:14.760 worked at National Labs, work in weapons programs and helped 0:02:14.800 --> 0:02:18.000 develop essentially weapons of mass destruction, whereas I try to 0:02:18.000 --> 0:02:20.040 stay away from that and work on things that will 0:02:20.040 --> 0:02:24.240 never affect anybody's life. So maybe there's a parallel there. Um. 0:02:24.320 --> 0:02:28.640 But Crystal, you are a PhD scientist, but you're also 0:02:28.720 --> 0:02:31.919 not just a scientist, right, You're a dancer, you're a 0:02:31.960 --> 0:02:36.040 movie star, You're I guess I should have led with that. 0:02:36.160 --> 0:02:40.600 So I became part of the PhD Comics universe, um 0:02:40.720 --> 0:02:43.680 through the PhD movie. So I played Tagel in the 0:02:43.720 --> 0:02:46.840 PhD movie and the PhD movie too, and that's how 0:02:46.880 --> 0:02:49.400 I sort of came into ys Orbit and we've been 0:02:49.400 --> 0:02:53.120 working together on and off to audition for a movie. 0:02:53.160 --> 0:02:56.360 I mean, you ever acted before? I had acted in 0:02:56.480 --> 0:03:00.760 children's theater, So nothing on camera, nothing serious that was 0:03:00.800 --> 0:03:04.960 going to be seen on every continent on the planet. 0:03:05.480 --> 0:03:07.080 And it was really hard for me because I had 0:03:07.080 --> 0:03:09.800 started grad school thinking I was going to give up 0:03:09.800 --> 0:03:11.840 my life in the performing arts. No more dance, no 0:03:11.880 --> 0:03:14.680 more theater, no no stages for me. I was going 0:03:14.760 --> 0:03:17.800 to be the best scientist anyone had ever seen. I 0:03:17.880 --> 0:03:22.000 was going to eat, sleep, breathe science, do the right thing, 0:03:22.120 --> 0:03:25.919 be a good person. Um. But I had been reading 0:03:26.040 --> 0:03:29.560 PhD comics since I was working in the lab. And 0:03:29.600 --> 0:03:32.280 when you get an email saying PhD Comics is coming 0:03:32.720 --> 0:03:35.160 to your campus and they want to make a movie, 0:03:35.240 --> 0:03:39.520 a live action movie or live action YouTube series about 0:03:39.560 --> 0:03:43.200 this comic that has been your you know, your inspiration 0:03:43.320 --> 0:03:45.400 for grad school? Do you want to be a part 0:03:45.400 --> 0:03:47.600 of And it's like therapy for people, right. And I 0:03:47.720 --> 0:03:49.360 traveled with or hate people who come up to him 0:03:49.360 --> 0:03:51.440 and say, it hadn't been for your comic, I would 0:03:51.440 --> 0:03:54.440 never have made it through grad school, right, I mean, 0:03:54.480 --> 0:03:56.080 if it hadn't been for the comic, I never would 0:03:56.080 --> 0:03:59.040 have gone to grad school. So that's that's a whole 0:03:59.040 --> 0:04:03.280 other conversation shin before then, to blame you for your 0:04:03.280 --> 0:04:05.440 grad school. Yes, they hold him very much to blame. 0:04:05.560 --> 0:04:09.360 I don't know if he knows that, Jorge, it's your fault, um, 0:04:09.400 --> 0:04:11.720 But yeah, it was just the carrot was too big. 0:04:11.800 --> 0:04:15.960 So I was I was at a Biophysics Society meeting, 0:04:16.480 --> 0:04:19.840 which is about three hours away from Pasadena at the 0:04:19.880 --> 0:04:23.640 time that Jorge was running auditions for the PhD movie, 0:04:24.040 --> 0:04:27.440 and I went to my last session, got in the car, 0:04:27.640 --> 0:04:31.520 drove from San Diego up to Pasadena audition for the movie, 0:04:31.680 --> 0:04:33.720 and then drove back so I could be there for 0:04:33.839 --> 0:04:36.480 my eight am poster session the next morning. Like my 0:04:36.480 --> 0:04:40.000 my advisor like as if as if I was never gone, 0:04:40.520 --> 0:04:43.680 he would never know. Yeah, And that was sort of 0:04:44.080 --> 0:04:46.600 the beginning of the end for me, because through working 0:04:46.640 --> 0:04:50.400 with Jorge, I discovered that science communication was an area 0:04:50.440 --> 0:04:53.159 that I could work in after grad school, and that's 0:04:53.279 --> 0:04:55.320 what I do now. I host a show for a 0:04:55.440 --> 0:04:58.760 Voice of America that highlights science and technology that's happening 0:04:58.760 --> 0:05:02.719 here in the United States. It's broadcast internationally. UM I 0:05:02.800 --> 0:05:05.520 was recently selected as one of the Triple A s 0:05:05.600 --> 0:05:08.480 if THEN Ambassadors. I'm a role model for women in STEM. 0:05:08.520 --> 0:05:11.520 Thank you, and I'm really excited about what that means. 0:05:11.600 --> 0:05:15.240 And I've you know, I love doing these types of things. 0:05:15.240 --> 0:05:17.240 I'm happy to sit down here with you and do 0:05:17.279 --> 0:05:19.120 you feel like people these days still have to sort 0:05:19.160 --> 0:05:22.000 of choose between having a career in science or having 0:05:22.000 --> 0:05:24.680 a career in sort of the creative sector art, dance, 0:05:24.880 --> 0:05:27.440 you know, public speaking, or do you think it's more 0:05:27.480 --> 0:05:29.800 opening now for people to bridge that gap and live 0:05:30.040 --> 0:05:32.479 two lives and not have to hide from their advisor 0:05:32.760 --> 0:05:35.400 that they're doing this other thing. I think that the 0:05:35.440 --> 0:05:38.920 Ivory Tower is still pretty restrictive in terms of what 0:05:39.000 --> 0:05:43.320 it will accept for its tenure track faculty. But I 0:05:43.360 --> 0:05:46.400 think that if you haven't chosen that as your path 0:05:46.480 --> 0:05:50.720 to walk, there's a lot more leniency. UM. You asked 0:05:50.720 --> 0:05:54.080 about careers. I think it's difficult to make a full 0:05:54.160 --> 0:05:58.240 living in the arts and a full living in science. 0:05:58.400 --> 0:06:01.159 So in that respect, Abe you would have to choose 0:06:01.200 --> 0:06:04.520 one or the other. But there's so many exciting spaces 0:06:04.600 --> 0:06:08.279 for collaboration. I don't feel that anyone should feel that 0:06:08.360 --> 0:06:11.120 they have to give one of those up in order 0:06:11.160 --> 0:06:13.240 to do the other. Well. I'm really excited about the 0:06:13.320 --> 0:06:15.599 idea that science could be more open to more kinds 0:06:15.600 --> 0:06:17.880 of people, not just people who look different or come 0:06:17.880 --> 0:06:20.640 from different places, but people whose interests are broader, and 0:06:20.640 --> 0:06:22.320 that we don't have to be only people who are 0:06:22.320 --> 0:06:25.400 super zero focused on exactly this one kind of science, 0:06:25.440 --> 0:06:27.120 and then they have other interests and they do other 0:06:27.160 --> 0:06:28.880 things in their life. I think that's probably going to 0:06:28.960 --> 0:06:31.760 be good for science and also good for science communication 0:06:31.839 --> 0:06:33.600 if we have people from science who know how to 0:06:33.640 --> 0:06:36.440 do this thing. In my lab, specifically, I encourage the 0:06:36.480 --> 0:06:39.479 students to do science communication, send them to conferences, this 0:06:39.560 --> 0:06:41.040 kind of thing. I don't know if that's good for 0:06:41.080 --> 0:06:43.480 their careers or not, but I figured, since I try 0:06:43.520 --> 0:06:45.640 to do science communication, that I should try to not 0:06:45.720 --> 0:06:48.040 prevent my students from also doing it. I don't know 0:06:48.200 --> 0:06:50.400 if that's a good idea or not, but on this 0:06:50.760 --> 0:06:56.120 open minded process I'm experimenting on my students, but also 0:06:56.160 --> 0:06:59.160 on this podcast, we want people to understand that everybody 0:06:59.200 --> 0:07:01.440 can understand scien It's one of the goals of this 0:07:01.480 --> 0:07:03.760 podcast is to zoom around the universe and take crazy, 0:07:03.800 --> 0:07:07.560 amazing things and make them actually understandable, not just jargon 0:07:07.680 --> 0:07:10.239 said while waving your hands, which isn't helpful on podcast, 0:07:10.560 --> 0:07:13.040 but people can go away and feel like I get it, 0:07:13.080 --> 0:07:15.640 I know what that is. I understand relativity now, and 0:07:15.800 --> 0:07:17.960 I want to make breakdown those barriers and make people 0:07:17.960 --> 0:07:20.600 feel like they can figure it out too. Oh I'm 0:07:20.760 --> 0:07:24.200 all for that, all right, So let's get into it today. 0:07:24.240 --> 0:07:26.520 We're gonna talk about something really amazing, as we alluded 0:07:26.560 --> 0:07:29.800 to earlier, something that's all around us, a secret of 0:07:29.840 --> 0:07:32.800 the universe, deep dark knowledge about how things in the 0:07:32.840 --> 0:07:35.160 universe work, the ancient history of the universe that has 0:07:35.200 --> 0:07:37.480 just been sort of floating around in the air around 0:07:37.520 --> 0:07:41.200 us with nobody noticing for I guess thousands of years. 0:07:41.800 --> 0:07:45.320 Literally like a color you can't see, yes, exactly, if 0:07:45.360 --> 0:07:47.040 only our eyes could open it. I talk a lot 0:07:47.080 --> 0:07:49.600 in this podcast about opening new eyes. I feel like 0:07:49.640 --> 0:07:52.040 science is always figuring out new ways to look at 0:07:52.080 --> 0:07:54.480 the universe, and every time we do so, we realize 0:07:54.520 --> 0:07:57.200 the universe. Wow. It looks so different and using these 0:07:57.240 --> 0:08:01.040 other eyes than than the ones we're familiar with. So yeah, 0:08:01.080 --> 0:08:03.200 it's like a color that we can't see. And also 0:08:03.400 --> 0:08:05.520 it's one of my favorite stories because it was discovered 0:08:05.640 --> 0:08:07.920 kind of by accident. You know, Folks were trying to 0:08:07.920 --> 0:08:11.240 do one thing, developed this technology, accidentally stumbled into this 0:08:11.360 --> 0:08:14.840 incredible wealth of knowledge about the universe. I think that 0:08:14.880 --> 0:08:18.760 there's a lot of really cool stories, especially in astro 0:08:19.480 --> 0:08:23.800 about accidental major discoveries. That seems to be one of 0:08:23.880 --> 0:08:27.320 the really big fields of science where that that's possible. 0:08:27.760 --> 0:08:30.320 I feel like I'm so jealous sometimes with astronomy because 0:08:30.360 --> 0:08:32.160 every time they look out into the universe with a 0:08:32.200 --> 0:08:34.480 new device, they find something that doesn't make any sense. 0:08:34.920 --> 0:08:37.360 We talked about recently the podcast These Fermi Bubbles. It's 0:08:37.400 --> 0:08:39.839 like huge structure the size of the galaxy and nobody 0:08:39.920 --> 0:08:43.120 ever seen before, found ten years ago. But whereas in 0:08:43.160 --> 0:08:46.080 particle physics it feels sometimes a little bit more difficult 0:08:46.080 --> 0:08:48.640 to find new things. It's rarer that we like find 0:08:48.679 --> 0:08:52.200 a new particle nobody hadn't expected. Um. So sometimes I'm 0:08:52.240 --> 0:08:54.400 jealous of astronomers because they get to they get to 0:08:54.400 --> 0:08:57.240 see things they don't understand more often, and that's like 0:08:57.280 --> 0:09:00.480 the launching point for discovery, right when the universe gives 0:09:00.480 --> 0:09:02.520 you a clue and says, here's something you didn't expect, 0:09:02.640 --> 0:09:04.600 then you get to unravel it. I feel like, for 0:09:04.600 --> 0:09:07.240 a chemistry and neuroscience, which are my area, is like 0:09:07.640 --> 0:09:11.200 the analogous story is like the discovery of LSD. Like 0:09:11.280 --> 0:09:13.720 some chemist was like, what's this? I'm going to eat it? 0:09:13.720 --> 0:09:19.640 And I was like, WHOA, Well that's the big leap 0:09:19.679 --> 0:09:23.000 forward in neuroscience. So what were they trying to do 0:09:23.120 --> 0:09:26.000 when they discovered LSD? I don't actually remember. It's like 0:09:26.080 --> 0:09:29.959 such an irrelevant part of the discovery story that I can't, 0:09:30.120 --> 0:09:31.720 off the top of my head even remember what they 0:09:31.720 --> 0:09:35.360 were trying to synthesize. Al Right, well, today we're talking 0:09:35.360 --> 0:09:39.920 about something unseen but then discovered something a surprisingly revealed 0:09:39.920 --> 0:09:42.800 that told us deep knowledge about the universe. So let's 0:09:42.800 --> 0:09:44.880 not tease it anymore. Today we're going to be answering 0:09:44.880 --> 0:09:55.360 the question what is the cosmic microwave background? So this 0:09:55.440 --> 0:09:57.760 is something which is invisible and carries a huge amount 0:09:57.800 --> 0:10:01.320 of information all around us, and it discovered by accident 0:10:01.400 --> 0:10:04.679 about fifty years ago. It's a pretty funny story. Actually, 0:10:04.920 --> 0:10:07.800 some folks were building a radio telescope to do something else. 0:10:07.840 --> 0:10:10.960 They want to do radar and communication, and so they 0:10:11.040 --> 0:10:14.560 built this device and then they heard this buzz on 0:10:14.600 --> 0:10:17.840 the device. Is this noise? And at first they were like, oh, 0:10:17.880 --> 0:10:19.920 this is annoying and we can't get rid of it. 0:10:19.920 --> 0:10:22.520 They thought it was like a malfunction of their telescope. 0:10:23.080 --> 0:10:27.679 Um they couldn't understand where it came from. So microwaves, 0:10:28.000 --> 0:10:33.240 can we just start there? I have one. I so 0:10:33.280 --> 0:10:35.679 you're an expert in microwave backgrounds because you can use 0:10:35.679 --> 0:10:39.480 a microwave. I can use a microwave. I'm an expert microwaver. 0:10:40.559 --> 0:10:43.640 I'm not sure how to extrapolate my knowledge of heating 0:10:43.679 --> 0:10:47.320 up soup to the beginning of the universe. Can you 0:10:47.320 --> 0:10:51.960 help me draw that connection? Yes, for once our podcast 0:10:51.960 --> 0:10:54.800 will actually have practical knowledge and it folks. Yes, we'll 0:10:54.840 --> 0:10:56.880 draw that connection. But first I was wondering what everybody 0:10:56.960 --> 0:11:00.520 knew about microwaves, Like, do people understand microwave back ground radiation? 0:11:00.559 --> 0:11:02.319 Dos that make sense to them? Is this something everybody 0:11:02.360 --> 0:11:04.720 is already familiar with or is it something nobody had 0:11:04.800 --> 0:11:07.480 ever heard of before? And so, as usual, I walked 0:11:07.480 --> 0:11:10.480 around campus here you see Irvine, and I'm eternally grateful 0:11:10.520 --> 0:11:13.640 to the students here for being open to being asked 0:11:13.679 --> 0:11:17.439 these random questions by a scruffy looking physicist. So before 0:11:17.480 --> 0:11:20.240 you hear their answers, think to yourself, do you know 0:11:20.320 --> 0:11:22.800 what the cosmic microwave background is? How could you explain 0:11:22.840 --> 0:11:25.480 it to a random dude who accosted you on the street. 0:11:26.320 --> 0:11:28.560 Here's what, folks that you see Irvine had to say 0:11:28.800 --> 0:11:35.880 something that's ongoing in the atmosphere having to do with microwaves. 0:11:36.000 --> 0:11:40.360 I don't know, no micro waves that are present everywhere. 0:11:40.720 --> 0:11:42.840 I do not know. I've heard the topic. I've watched 0:11:42.840 --> 0:11:45.360 couple of videos, but I don't understand that whatsoever. Wave 0:11:45.480 --> 0:11:48.400 like yeah, I don't know it's material or just wave. 0:11:48.559 --> 0:11:52.280 There is something like that a president outside Okay, I 0:11:52.320 --> 0:11:54.480 don't know. It's a elemnent of those in a big thing. 0:11:54.800 --> 0:11:56.680 All right, So Crystal, what do you think of those answers? 0:11:56.720 --> 0:12:01.600 You impressed? Um, I don't think i'd say impressed. But 0:12:01.679 --> 0:12:05.520 there's quite a diversity of topics that the answers are 0:12:05.559 --> 0:12:09.839 connecting to, like electricity or something. Yes, yeah, well, it's 0:12:10.040 --> 0:12:13.080 like electricity or something that's a pretty broad answer, so 0:12:13.120 --> 0:12:15.839 it's pretty close. You could tell that some people had 0:12:15.880 --> 0:12:17.560 no idea what we're talking about and just sort of 0:12:17.600 --> 0:12:20.520 guest generally physics. A few people had heard of it. 0:12:20.760 --> 0:12:22.679 I like think, I said, I watched a couple of videos, 0:12:22.720 --> 0:12:25.000 but I have no idea what it is that tells 0:12:25.000 --> 0:12:27.199 me that there's an opening here to really explain the 0:12:27.280 --> 0:12:30.440 microwave background. She really needs this podcast, Yes, exactly, this 0:12:30.480 --> 0:12:34.320 one is for you, dude. But I like the I 0:12:34.400 --> 0:12:37.440 like this answer remnant of the Big Bang. I mean, 0:12:37.480 --> 0:12:40.400 we're really getting to something there, aren't we. Yes, absolutely, 0:12:40.480 --> 0:12:43.920 somebody definitely knew what we were talking about. So let's 0:12:43.960 --> 0:12:46.440 get back to your question and break it down. I 0:12:46.559 --> 0:12:49.120 know how to heat up soup in a microwave. I 0:12:49.200 --> 0:12:53.280 even know that microwaves are long radio waves. I think 0:12:53.320 --> 0:12:56.240 of them as really big waves. I mean, I'm a 0:12:56.520 --> 0:12:59.560 I did a lot of fluorescence microscopy UM in a lab, 0:12:59.640 --> 0:13:03.079 so I like nanometer is a scale that I'm used 0:13:03.080 --> 0:13:05.240 to dealing with in microwaves, I think of being so 0:13:05.280 --> 0:13:09.920 big as to be ineligible. UM, so help me out here. Yeah, 0:13:10.000 --> 0:13:12.480 I love this sense of scales and science right for me. 0:13:12.520 --> 0:13:15.080 For example, anything big on the proton is like way 0:13:15.080 --> 0:13:19.199 too big and complicated even think about, right, whereas mechanical 0:13:19.200 --> 0:13:23.400 engineers never think about the individual molecules. So microwaves is 0:13:23.440 --> 0:13:28.240 really really just a relative term. Remember, microwaves are electromagnetic radiation, 0:13:28.559 --> 0:13:31.600 just like light. So everything that's coming into your eyeballs 0:13:31.679 --> 0:13:34.840 is electromagnetic radiation, but it's part of a much larger spectrum. 0:13:35.000 --> 0:13:37.720 The visible light is just this one little slice that 0:13:37.760 --> 0:13:39.440 we happen to be able to see because our eyes 0:13:39.480 --> 0:13:43.200 react to it. But down the lower um frequency, the 0:13:43.280 --> 0:13:45.679 longer wavelengths, you have radio waves, and at the higher 0:13:45.800 --> 0:13:48.080 end you have gamma rays and X rays. It's all 0:13:48.120 --> 0:13:52.200 just part of the same big electromagnetic family. And microwaves 0:13:52.440 --> 0:13:54.640 are a kind of radio waves, as you said, and 0:13:54.679 --> 0:13:57.360 they're might be called micro because they're short for radio waves. 0:13:57.400 --> 0:14:00.480 Radio waves can have wavelengths like meters long. It's just 0:14:00.679 --> 0:14:03.120 all about scale, it's all about scales, and so compared 0:14:03.160 --> 0:14:06.800 to that, microwaves, which have wavelength like millimeter, are really small. 0:14:06.840 --> 0:14:09.400 But of course you know, they're huge compared to visible 0:14:09.480 --> 0:14:12.880 light or gamma rays or anything that I know anything about. Frankly, 0:14:14.000 --> 0:14:17.080 So microwaves are mega waves for me and microwaves for 0:14:17.240 --> 0:14:21.520 most people. So cosmic microwave background. The connection is the 0:14:21.680 --> 0:14:24.760 wavelength of the electromagnetic radiation. And we talked on this 0:14:24.800 --> 0:14:27.800 podcast recently about how microwaves work, and they work in 0:14:27.840 --> 0:14:30.160 the same way. They pump this same kind of radiation 0:14:30.280 --> 0:14:32.960 into your soup to make it hot, using it to 0:14:33.240 --> 0:14:36.720 add energy to the system. That's right, Um, and then 0:14:36.800 --> 0:14:38.920 fueling you so that you can think about the universe 0:14:38.920 --> 0:14:41.120 and reveal all of its secrets. I'll work on that, 0:14:41.840 --> 0:14:45.640 all of the secrets revealed. Yeah, exactly. Um, Jorge usually 0:14:45.680 --> 0:14:48.240 has a banana before every podcast because apparently he can't 0:14:48.280 --> 0:14:50.040 think without a Is that's something you know about him 0:14:50.040 --> 0:14:53.400 through I know that he definitely does not operate without 0:14:53.440 --> 0:14:56.400 a banana. I do not operate without a coffee. So 0:14:56.600 --> 0:14:59.000 as long as he's got bananas and I've got coffee, 0:14:59.080 --> 0:15:02.160 we're usually good to go. That's all that's required around here. Well, 0:15:02.320 --> 0:15:04.280 this is a perfect spot to take a break. We'll 0:15:04.280 --> 0:15:20.320 be right back. Um. Yeah, So, cosmic microwave background radiation. 0:15:20.360 --> 0:15:23.240 The microwave radiation part just refers to the length of 0:15:23.240 --> 0:15:25.760 the waves of the electromagnetic radiation. So where are the 0:15:25.800 --> 0:15:29.520 waves coming from? Yeah, they're coming from everywhere, Like if 0:15:29.520 --> 0:15:32.960 you look out into the sky, you see this radiation 0:15:33.120 --> 0:15:35.560 coming from everywhere. And that was the weird thing about 0:15:35.560 --> 0:15:38.080 their discovery. When they turned on this radio telescope for 0:15:38.120 --> 0:15:40.960 the first time, they heard this buzz and they heard 0:15:41.000 --> 0:15:43.960 it from every direction. There's sort of two answer parts 0:15:44.040 --> 0:15:46.680 to that answer. One is where do we see them? Right, 0:15:46.720 --> 0:15:48.400 And it's coming from every direction, so we see it 0:15:48.440 --> 0:15:51.320 from everywhere in the sky. And often if you see 0:15:51.360 --> 0:15:54.120 a map of the cosmic microwave background radiation, it's this 0:15:54.200 --> 0:15:56.920 weird ellipse with these little dots on it, and that's 0:15:56.920 --> 0:15:59.880 an attempt to describe what you see in each direction 0:16:00.040 --> 0:16:03.160 the sky. So, because the sky is a circle, right, 0:16:03.320 --> 0:16:05.400 the Earth is a sphere. It's hard to map a 0:16:05.440 --> 0:16:08.000 sphere onto a flat piece of paper. The best way 0:16:08.000 --> 0:16:10.040 to describe what you see is if you could print 0:16:10.040 --> 0:16:12.360 it on the inside of a sphere, so you could 0:16:12.400 --> 0:16:14.240 look at and say, oh, in this direction, we see this. 0:16:14.320 --> 0:16:16.960 In that direction, we see this. The same way, it's 0:16:16.960 --> 0:16:18.760 hard to make a map of the stars you see 0:16:18.760 --> 0:16:20.720 in the sky, right. The best way to do that 0:16:20.800 --> 0:16:22.480 is like a planetarium, you can print them on the 0:16:22.520 --> 0:16:24.960 inside of a curved surface, so you can show what 0:16:25.000 --> 0:16:28.120 we're seeing. So what we see when we talk about 0:16:28.120 --> 0:16:31.200 the cosmic microwave background is we see this buzz, this 0:16:31.280 --> 0:16:36.160 electromagnetic radiation from every direction at once, so just filling 0:16:36.400 --> 0:16:39.320 the space that is the universe. Yeah, it's coming from 0:16:39.400 --> 0:16:42.680 every direction and hitting us. And it's everywhere. Like if 0:16:42.680 --> 0:16:45.240 we were here or around Jupiter, or in the center 0:16:45.240 --> 0:16:48.440 of the galaxy or in between galaxies, we would see 0:16:48.440 --> 0:16:52.800 it everywhere. So it's originating from the universe. It's just 0:16:52.840 --> 0:16:56.320 an energy that now exists and bounces around and comes 0:16:56.360 --> 0:16:59.640 from everywhere. Yeah, it comes from everywhere. And that's the 0:16:59.680 --> 0:17:01.280 confused seeing part, I think to a lot of people, 0:17:01.280 --> 0:17:03.960 because people think, Okay, it's light, so it's traveling at 0:17:04.040 --> 0:17:07.200 light speed and it's getting here. How can it be 0:17:07.280 --> 0:17:10.280 getting here? Where did it come from? Right? And that's 0:17:10.320 --> 0:17:13.320 pretty confusing if you imagine that, if you think about 0:17:13.320 --> 0:17:15.760 the beginning of the universe as a point and from 0:17:15.800 --> 0:17:18.719 that point things flew outwards, and people trying to imagine, well, 0:17:18.760 --> 0:17:22.120 then if it's getting here now it's coming from that point, 0:17:22.119 --> 0:17:24.720 how can we be seeing it from two directions? And 0:17:24.760 --> 0:17:26.600 the reason that's confusing is that I think that's the 0:17:26.680 --> 0:17:28.560 wrong way to think about the start of the universe. 0:17:28.600 --> 0:17:30.399 Oh my gosh, how should I be thinking about the 0:17:30.400 --> 0:17:34.800 start of the universe. Well, you start with the bowl soup, right, Um. No. 0:17:35.280 --> 0:17:36.760 The way I think about the start of the universe 0:17:36.920 --> 0:17:40.080 is that it started off infinite, that it's the moment 0:17:40.119 --> 0:17:42.639 of creation is not a single point in space, but 0:17:42.680 --> 0:17:46.240 that the Big Bang happened everywhere all at once. There 0:17:46.280 --> 0:17:49.439 was sort of multiple starts from every direction. And what 0:17:49.480 --> 0:17:52.320 we're seeing now is leftover bits from really far away 0:17:52.520 --> 0:17:54.720 in that in one direction, and really far away in 0:17:54.760 --> 0:17:57.600 the other direction. So if I'm looking at the cosmic 0:17:57.600 --> 0:18:01.000 microwave background reradiation, I'm seeing light that came from the 0:18:01.119 --> 0:18:03.520 very beginning of the universe. It took almost fourteen billion 0:18:03.600 --> 0:18:05.720 years to get here from somewhere really far away in 0:18:05.720 --> 0:18:08.200 one direction. And I'll turn around and I look in 0:18:08.280 --> 0:18:11.120 the other direction. I'm seeing light come from the other direction, 0:18:11.240 --> 0:18:13.680 which came really far away from the other direction, from 0:18:13.720 --> 0:18:17.359 somewhere else, really really far away. So these two pieces 0:18:17.400 --> 0:18:20.600 of light haven't talked to each other ever. Are they 0:18:20.800 --> 0:18:22.879 meeting for the first time in the history of the 0:18:22.960 --> 0:18:26.040 universe here on Earth. So they're not coming from the 0:18:26.080 --> 0:18:29.160 same place. It's not like we're looking at a little object. 0:18:29.400 --> 0:18:33.200 We're looking at a huge universe at its beginning. Every 0:18:33.240 --> 0:18:35.520 direction you look at, you're looking at a different part 0:18:35.520 --> 0:18:37.920 of the early universe. So does that mean that the 0:18:38.080 --> 0:18:41.560 different particles, the different waves of light that are meeting 0:18:41.640 --> 0:18:43.960 here for the very first time can tell us different 0:18:43.960 --> 0:18:47.119 things about the beginning of the universe. Yes, absolutely, they 0:18:47.119 --> 0:18:49.240 tell us what was going on at one spot of 0:18:49.280 --> 0:18:50.959 the universe over there, and what was going on at 0:18:50.960 --> 0:18:53.000 one spot of the universe over there, just the same 0:18:53.040 --> 0:18:54.960 way when we look at the night sky. Now you 0:18:55.000 --> 0:18:57.040 look at one star, it's telling you that light is 0:18:57.040 --> 0:18:59.840 telling you what happened a long time ago in that direction. 0:19:00.080 --> 0:19:02.800 You turn another way, and like from another star is 0:19:02.840 --> 0:19:04.679 telling you what happened in a totally different part of 0:19:04.680 --> 0:19:07.680 the universe, also a long time ago. Those two photons 0:19:07.680 --> 0:19:09.639 are also meeting for the first time. So I have 0:19:09.800 --> 0:19:13.479 a lot of questions about how that information is carried 0:19:13.600 --> 0:19:18.320 and decoded. But first I'd like to ask, when this 0:19:18.400 --> 0:19:22.199 background radiation was discovered, what did we think it was. 0:19:22.640 --> 0:19:24.720 How did we know that it could teach us and 0:19:24.760 --> 0:19:27.480 tell us things. Yeah, if that's a really fun part 0:19:27.480 --> 0:19:29.919 of the story because the guys who discovered this, they 0:19:29.960 --> 0:19:31.960 weren't looking for it, but there was another team of 0:19:32.000 --> 0:19:34.800 people who were looking for it, and they got scooped. 0:19:35.240 --> 0:19:37.680 So there was a team around the corner. This telescope 0:19:37.680 --> 0:19:39.960 they built was in New Jersey and it just happened 0:19:40.000 --> 0:19:41.480 to be around the corner from Princeton. It was a 0:19:41.480 --> 0:19:44.159 team of Princeton who was looking for this radiation. They 0:19:44.160 --> 0:19:46.560 were like scrambling to build the device. They could see it, 0:19:46.720 --> 0:19:48.320 and they got scooped by these guys who were like 0:19:48.520 --> 0:19:51.040 building something to do something else. The reason they were 0:19:51.040 --> 0:19:52.679 looking for it is that there was this idea that 0:19:52.680 --> 0:19:55.320 we could find evidence for the Big Bang. And this 0:19:55.359 --> 0:19:56.960 is back in the sixties when the Big Bang was 0:19:57.000 --> 0:20:00.399 still like kind of a crazy idea, not neces serily 0:20:00.440 --> 0:20:04.160 totally accepted. Definitely not a television show, yeah, not yet, 0:20:04.840 --> 0:20:10.920 a hilarious television show that probably gates stereotypes about scientists. Um. 0:20:10.960 --> 0:20:14.040 But the idea was that if the universe had started 0:20:14.320 --> 0:20:17.400 smaller or more dense right at the universe had started 0:20:17.480 --> 0:20:22.080 from um really dense mass and then exploded, then originally 0:20:22.119 --> 0:20:25.639 it was sort of hotter and denser. And the reason 0:20:25.680 --> 0:20:28.320 people thought that this radiation might exist. Is that they 0:20:28.720 --> 0:20:31.040 looked back into the history of the universe. They said, Okay, 0:20:31.040 --> 0:20:33.240 the universe now is a bunch of stars and galaxies, 0:20:33.800 --> 0:20:36.080 but if there had been a big bang, then the 0:20:36.160 --> 0:20:38.960 universe we sort of rewind the history of the universe. 0:20:39.000 --> 0:20:42.360 Everything pulls together and gets hotter and denser, and eventually 0:20:42.359 --> 0:20:45.000 it gets so hot and dense that it becomes a plasma. 0:20:45.280 --> 0:20:48.000 And a plasma is really interesting because light can't just 0:20:48.040 --> 0:20:51.080 passed through it. It's opaque. So this this moment in 0:20:51.080 --> 0:20:53.320 the history of the universe they thought when the universe 0:20:53.359 --> 0:20:56.440 went from opaque like like couldn't go through it too transparent, 0:20:56.920 --> 0:21:00.520 Suddenly the universe cooled um and became crystal clear, so 0:21:00.560 --> 0:21:02.639