1 00:00:08,480 --> 00:00:12,680 Speaker 1: Hey, Jorge, who is the oldest person you know? I 2 00:00:12,720 --> 00:00:15,720 Speaker 1: have a couple of uncles that are in their late eighties. 3 00:00:16,000 --> 00:00:18,119 Speaker 1: I think that's about as old as it gets in 4 00:00:18,160 --> 00:00:20,119 Speaker 1: my family. That's pretty good. They must have eaten a 5 00:00:20,120 --> 00:00:22,960 Speaker 1: lot of bananas or zero bananas, whichever is best. I 6 00:00:23,000 --> 00:00:26,799 Speaker 1: can't keep trying. May either been at a neutral What 7 00:00:26,880 --> 00:00:30,120 Speaker 1: about you? My grandmother, my mom's mom is a hundred 8 00:00:30,120 --> 00:00:33,800 Speaker 1: and five years old and she still beats me at scrabble. Wow, 9 00:00:33,880 --> 00:00:36,440 Speaker 1: what's her secret? I think she just likes beating people 10 00:00:36,440 --> 00:00:39,880 Speaker 1: at scrabble, and that's what keeps her alive. I guess 11 00:00:39,880 --> 00:00:58,600 Speaker 1: what age comes wisdom and a very large vocabulary. Hi 12 00:00:58,680 --> 00:01:01,880 Speaker 1: am orgem a cartoonists and the creator of PhD Comics. Hi. 13 00:01:02,080 --> 00:01:05,720 Speaker 1: I'm Daniel. I'm a particle physicist and my kids think 14 00:01:05,760 --> 00:01:08,039 Speaker 1: I'm pretty old, but I feel young at heart. Welcome 15 00:01:08,040 --> 00:01:10,600 Speaker 1: to our podcast, Daniel and Jorge Explain the Universe, a 16 00:01:10,680 --> 00:01:13,399 Speaker 1: production of I Heart Radio in which we talk about 17 00:01:13,440 --> 00:01:16,200 Speaker 1: all the amazing things in the universe, the new stuff, 18 00:01:16,240 --> 00:01:18,840 Speaker 1: the old stuff, the close stuff, the far away stuff. 19 00:01:18,880 --> 00:01:21,920 Speaker 1: We talk about everything you want to hear about. We 20 00:01:22,080 --> 00:01:24,319 Speaker 1: break it down, we explain it to you in a 21 00:01:24,360 --> 00:01:26,840 Speaker 1: way that we hope also makes you laugh. It's right, 22 00:01:26,880 --> 00:01:29,160 Speaker 1: we talk about the boring stuff in the universe, but 23 00:01:29,200 --> 00:01:31,600 Speaker 1: we also like to talk about the extreme stuff in 24 00:01:31,640 --> 00:01:34,280 Speaker 1: the universe, the things that are pushing the boundaries of 25 00:01:34,280 --> 00:01:37,800 Speaker 1: what is possible in this crazy cosmos. That's right because 26 00:01:37,840 --> 00:01:40,920 Speaker 1: the extremes tell us about what the rules are. How 27 00:01:40,959 --> 00:01:44,200 Speaker 1: hot can something possibly get, how cold can something be, 28 00:01:44,319 --> 00:01:47,280 Speaker 1: how fast can it's been? What is the brightest possible thing? 29 00:01:47,640 --> 00:01:49,840 Speaker 1: Because usually when we look at the extremes is when 30 00:01:49,880 --> 00:01:53,000 Speaker 1: we learned about something new in the universe, we say, wow, 31 00:01:53,040 --> 00:01:55,520 Speaker 1: we didn't realize it was possible to shoot particles at 32 00:01:55,520 --> 00:01:58,120 Speaker 1: that high energy the Earth. What could be doing that? 33 00:01:58,640 --> 00:02:00,160 Speaker 1: So that's why it's a lot of fun to look 34 00:02:00,160 --> 00:02:02,800 Speaker 1: at the most extreme stuff in the universe. And so 35 00:02:02,880 --> 00:02:05,960 Speaker 1: we have a series of episodes dealing with the most 36 00:02:06,080 --> 00:02:08,040 Speaker 1: of a lot of things in the universe. If you 37 00:02:08,080 --> 00:02:11,000 Speaker 1: look back to our archive, you can listen to episodes 38 00:02:11,040 --> 00:02:14,600 Speaker 1: about the biggest thing in the universe, the brightest things 39 00:02:14,600 --> 00:02:17,720 Speaker 1: in the universe, the darkest things in the universe. And 40 00:02:17,760 --> 00:02:20,799 Speaker 1: so today we'll have an episode about one such extremes. 41 00:02:20,919 --> 00:02:22,680 Speaker 1: Are are are we giving out awards? Should we be like 42 00:02:22,720 --> 00:02:26,079 Speaker 1: making trophies and handing them out to astrophysical objects, and 43 00:02:26,200 --> 00:02:29,400 Speaker 1: we we can send them as certificate, like an email certificate. 44 00:02:31,120 --> 00:02:33,760 Speaker 1: Maybe just being the subject of a whole podcast episode 45 00:02:34,120 --> 00:02:36,720 Speaker 1: is enough reward for them. Yeah, they can listen under CV, 46 00:02:36,919 --> 00:02:38,720 Speaker 1: or they can put a little like logo next to 47 00:02:38,760 --> 00:02:41,520 Speaker 1: their cover or something that says they were featured in 48 00:02:41,560 --> 00:02:44,920 Speaker 1: our podcast. That's right. I'm sure the supercluster we're in 49 00:02:45,200 --> 00:02:48,000 Speaker 1: is always emailing at CV around the universe. And by 50 00:02:48,080 --> 00:02:49,920 Speaker 1: the way, did you know I was the subject of 51 00:02:49,919 --> 00:02:54,320 Speaker 1: a podcast? What do you think the email addresses everywhere 52 00:02:55,240 --> 00:02:59,960 Speaker 1: everywhere at everything dot com. That's right. But even if 53 00:03:00,040 --> 00:03:03,040 Speaker 1: nobody is interested in winning these prizes, we are interested 54 00:03:03,080 --> 00:03:06,520 Speaker 1: in exploring them and talking about them because they're super fun. 55 00:03:06,680 --> 00:03:09,000 Speaker 1: Not only because it teaches us something about the universe, 56 00:03:09,040 --> 00:03:11,560 Speaker 1: but because these are the wow factors. These are the 57 00:03:11,639 --> 00:03:15,600 Speaker 1: reasons why the universe is amazing, because things are super 58 00:03:15,680 --> 00:03:19,040 Speaker 1: big and super hot and super fast and super spinny 59 00:03:19,080 --> 00:03:21,919 Speaker 1: and super everything. And so today on the program, we'll 60 00:03:21,960 --> 00:03:30,280 Speaker 1: be asking the question, what is the oldest thing in 61 00:03:30,360 --> 00:03:35,320 Speaker 1: the universe? The oldest thing, not the oldest person. We 62 00:03:35,400 --> 00:03:39,160 Speaker 1: already determined that's her grandmother. No, she's she's like twenty 63 00:03:39,200 --> 00:03:41,560 Speaker 1: something years away from being the oldest person. The oldest 64 00:03:41,600 --> 00:03:44,200 Speaker 1: person is like almost a hundred and thirty. It's ridiculous. 65 00:03:44,800 --> 00:03:46,960 Speaker 1: For real, Yeah, for real, Yeah, I think it was 66 00:03:47,000 --> 00:03:49,880 Speaker 1: like some old French lady. Don't you remember? There was 67 00:03:49,880 --> 00:03:53,000 Speaker 1: a guy when she was in her eighties. He bought 68 00:03:53,000 --> 00:03:55,880 Speaker 1: her apartment for some really low price under the deal 69 00:03:55,920 --> 00:03:58,080 Speaker 1: that she could live in it until she died. He 70 00:03:58,160 --> 00:04:00,360 Speaker 1: figured she was going to expire in a few years, 71 00:04:00,400 --> 00:04:02,560 Speaker 1: but then she outlived him, and she lived to one 72 00:04:02,600 --> 00:04:05,440 Speaker 1: twenty something and he died in his eighties, never having 73 00:04:05,440 --> 00:04:09,000 Speaker 1: moved into the apartment that he purchased. It's amazing. I'd 74 00:04:09,000 --> 00:04:11,360 Speaker 1: love to see that person plays grapple with your grandmother. 75 00:04:12,240 --> 00:04:14,280 Speaker 1: What do you think would win? I don't know. I 76 00:04:14,280 --> 00:04:17,880 Speaker 1: think there'd be a lot of cheating. I guess who's 77 00:04:17,880 --> 00:04:22,640 Speaker 1: going to call them out right? Exactly exactly. But I 78 00:04:22,640 --> 00:04:24,640 Speaker 1: think this is a really fun question because it makes 79 00:04:24,680 --> 00:04:27,000 Speaker 1: you think about the early days of the universe and 80 00:04:27,040 --> 00:04:30,680 Speaker 1: like what God formed first and then what's still around. 81 00:04:31,200 --> 00:04:34,680 Speaker 1: And it's also makes you understand like the grand sweep 82 00:04:34,760 --> 00:04:37,480 Speaker 1: of time. You know, a hundred deers seems like a 83 00:04:37,520 --> 00:04:40,000 Speaker 1: long time for us humans. But it's the blink of 84 00:04:40,000 --> 00:04:43,720 Speaker 1: an eye. Cosmologically, our universe has been around for billions 85 00:04:43,720 --> 00:04:45,880 Speaker 1: of years, and so it's it's fun to think about 86 00:04:45,880 --> 00:04:48,880 Speaker 1: those things that just exist on a completely different scale. 87 00:04:49,440 --> 00:04:51,000 Speaker 1: And I guess we need to get a little bit 88 00:04:51,040 --> 00:04:54,640 Speaker 1: philosophical here, because you know, this sort of opens up 89 00:04:54,640 --> 00:04:56,640 Speaker 1: a couple of questions. First of all, what do you 90 00:04:56,680 --> 00:04:59,039 Speaker 1: mean by the oldest thing in the universe? And I 91 00:04:59,040 --> 00:05:01,600 Speaker 1: guess do you mean the oldest surviving thing in the universe. 92 00:05:01,640 --> 00:05:03,760 Speaker 1: You know, there's a whole branch of philosophy, you know, 93 00:05:03,880 --> 00:05:06,600 Speaker 1: thing is um what is a thing? What defines a thing? 94 00:05:06,640 --> 00:05:09,279 Speaker 1: What isn't the thing? What makes something two things? Is 95 00:05:09,279 --> 00:05:12,400 Speaker 1: that a thing? Really? In philosophy? No, I just made 96 00:05:12,400 --> 00:05:14,680 Speaker 1: that up. We just founded a whole new branch of 97 00:05:14,680 --> 00:05:18,800 Speaker 1: philosophy right here on the podcast. It's the newest thing 98 00:05:18,839 --> 00:05:22,800 Speaker 1: in the universe, the latest thing. We should put a 99 00:05:22,920 --> 00:05:27,120 Speaker 1: sticker in ourselves saying, I philosophies. Yeah, it is an 100 00:05:27,120 --> 00:05:30,000 Speaker 1: interesting question. What do you call a thing? You have 101 00:05:30,080 --> 00:05:32,279 Speaker 1: to go through several categories and talk about what is 102 00:05:32,279 --> 00:05:35,760 Speaker 1: the oldest for various answers of the question what do 103 00:05:35,839 --> 00:05:39,239 Speaker 1: you mean by a thing? All? Right, well as usual, 104 00:05:39,279 --> 00:05:42,080 Speaker 1: we were wondering how many people out there thought they 105 00:05:42,160 --> 00:05:45,520 Speaker 1: knew what is the oldest thing in the universe? So 106 00:05:45,760 --> 00:05:49,600 Speaker 1: I solicited volunteers to answer questions without doing any research, 107 00:05:49,640 --> 00:05:52,440 Speaker 1: off the top of your head, answer a hard physics 108 00:05:52,520 --> 00:05:55,279 Speaker 1: question from a dude on the Internet, and of course 109 00:05:55,360 --> 00:05:57,880 Speaker 1: people were happy to oblige. So thank you to everybody 110 00:05:57,920 --> 00:06:01,320 Speaker 1: who participated, And if you would like to answer random 111 00:06:01,320 --> 00:06:04,440 Speaker 1: future physics questions, please write to me at questions at 112 00:06:04,520 --> 00:06:07,920 Speaker 1: Daniel and Jorge dot com. Before you listen to these answers, 113 00:06:08,000 --> 00:06:10,240 Speaker 1: think about it for a second. If someone ask you 114 00:06:10,480 --> 00:06:13,240 Speaker 1: what is the oldest thing in the universe, what would 115 00:06:13,279 --> 00:06:17,520 Speaker 1: you answer. Here's what people had to say. Maybe as 116 00:06:17,960 --> 00:06:23,160 Speaker 1: some proton it is a fortune thing. The oldest thing 117 00:06:23,160 --> 00:06:25,880 Speaker 1: in the universe, from what I understanding, would be the 118 00:06:26,000 --> 00:06:32,440 Speaker 1: leftover resident cosmic microwave radiation after the initial Big Bang. 119 00:06:33,320 --> 00:06:35,560 Speaker 1: But if you're looking for an actual object or a thing, 120 00:06:36,279 --> 00:06:43,279 Speaker 1: I believe primordial black holes, I'm thinking cosmic background radiation. 121 00:06:43,839 --> 00:06:47,760 Speaker 1: I think the oldest thing in the universe um is CMD. 122 00:06:47,960 --> 00:06:52,360 Speaker 1: That's what we can observe at least after that. I 123 00:06:52,400 --> 00:06:56,880 Speaker 1: think it is cluster of Alexi cluster, which is about 124 00:06:57,560 --> 00:07:00,600 Speaker 1: twelve and a half million years old. I'm gonna go 125 00:07:00,720 --> 00:07:07,040 Speaker 1: with space. How about that? Wow, tough question. Maybe black holes. 126 00:07:07,360 --> 00:07:09,200 Speaker 1: So I would say the oldest thing in the universe 127 00:07:09,240 --> 00:07:12,760 Speaker 1: would be quirks. But if you mean by something that 128 00:07:12,800 --> 00:07:15,800 Speaker 1: actually gets assembled, then I would say hydrogen. If you 129 00:07:15,800 --> 00:07:19,400 Speaker 1: don't mean an object, then I would say a primordial 130 00:07:19,560 --> 00:07:22,520 Speaker 1: black hole. I'm not entirely sure what the oldest thing 131 00:07:22,560 --> 00:07:25,800 Speaker 1: in the universe is. I know that after the Big 132 00:07:25,840 --> 00:07:29,520 Speaker 1: bag Um, as far as we know, that was just 133 00:07:29,800 --> 00:07:36,080 Speaker 1: plasma and quantum fluctuations. There weren't particles at that point um. 134 00:07:36,240 --> 00:07:41,160 Speaker 1: These quantum fluctuations we think may have caused primordial black holes. 135 00:07:41,200 --> 00:07:43,760 Speaker 1: So perhaps that's the oldest thing in the universe. Man, 136 00:07:43,800 --> 00:07:46,840 Speaker 1: there are some good answers there. Huh yeah, Wow, it's 137 00:07:46,840 --> 00:07:48,920 Speaker 1: been impressed. Some of these made me think, like, a 138 00:07:49,000 --> 00:07:52,040 Speaker 1: proton is a protonon of thing? I'm like, huh is 139 00:07:52,080 --> 00:07:54,480 Speaker 1: it a thing? If you asked the protein, it would 140 00:07:54,480 --> 00:07:56,840 Speaker 1: say it's definitely a thing, or it's like space. Somebody 141 00:07:56,840 --> 00:07:59,360 Speaker 1: said space like a space the thing? And could that 142 00:07:59,480 --> 00:08:01,880 Speaker 1: be all their than anything else. Yeah, that's a really 143 00:08:01,880 --> 00:08:04,160 Speaker 1: good question because you might then think, well, is the 144 00:08:04,280 --> 00:08:06,720 Speaker 1: universe a thing? Right, what's the oldest thing in the universe. 145 00:08:06,760 --> 00:08:12,960 Speaker 1: It's the universe Boom podcast over everything whatever, everything is 146 00:08:13,440 --> 00:08:15,600 Speaker 1: that that was there from the beginning of everything. Yeah, 147 00:08:15,600 --> 00:08:17,960 Speaker 1: and you might say everything is definitely a thing because 148 00:08:17,960 --> 00:08:20,160 Speaker 1: it has the word thing in it, But then nothing 149 00:08:20,360 --> 00:08:21,960 Speaker 1: is not a thing and it has the word thing 150 00:08:22,000 --> 00:08:25,360 Speaker 1: in it. So now I'm overthinking it or overthinking it. 151 00:08:25,480 --> 00:08:28,520 Speaker 1: I think you're trying to win a scrabble here. It 152 00:08:28,560 --> 00:08:32,000 Speaker 1: sounds like trying to argue what a word is. But yeah, 153 00:08:32,040 --> 00:08:34,200 Speaker 1: it's it's it's interesting to think about what is the 154 00:08:34,240 --> 00:08:38,440 Speaker 1: oldest thing because there is sort of an age to 155 00:08:38,480 --> 00:08:41,000 Speaker 1: the universe. That's right. When we look out to the universe, 156 00:08:41,240 --> 00:08:43,520 Speaker 1: we see that everything is rushing away from us, that 157 00:08:43,559 --> 00:08:46,760 Speaker 1: the universe is getting less and less dense. It's spreading out, 158 00:08:47,080 --> 00:08:49,920 Speaker 1: and when you run the clock backwards, everything compresses and 159 00:08:49,960 --> 00:08:53,160 Speaker 1: get back to some like original really high dense point. 160 00:08:53,679 --> 00:08:55,800 Speaker 1: And we have an age for that. We can project 161 00:08:55,800 --> 00:08:58,800 Speaker 1: that backwards in time, and it's about fourteen billion years 162 00:08:58,800 --> 00:09:01,959 Speaker 1: ago when everything was really hot and dense. Of course, 163 00:09:02,080 --> 00:09:05,160 Speaker 1: we don't really know what happens then our theories breakdown 164 00:09:05,200 --> 00:09:06,880 Speaker 1: at that moment. We don't know if there was a 165 00:09:06,880 --> 00:09:09,960 Speaker 1: singularity or something came before it or whatever. But that's 166 00:09:10,000 --> 00:09:12,960 Speaker 1: generally considered roughly to be the approximate age of the 167 00:09:12,960 --> 00:09:17,840 Speaker 1: whole universe just under fourteen billion years, fourteen billion years young, 168 00:09:19,360 --> 00:09:21,440 Speaker 1: and you could be fourteen billion years young. This could 169 00:09:21,480 --> 00:09:24,360 Speaker 1: be like the first moments of the universe on the 170 00:09:24,400 --> 00:09:28,160 Speaker 1: trillions or quadrillion years life cycle of the universe. Right, 171 00:09:28,200 --> 00:09:30,960 Speaker 1: we don't know how far down the road we've walked. 172 00:09:31,360 --> 00:09:33,800 Speaker 1: It seems like a long time, but then again, after 173 00:09:33,960 --> 00:09:36,760 Speaker 1: ten million years it might have seemed like a long time. 174 00:09:37,000 --> 00:09:39,200 Speaker 1: And we know now that that's only just the first blip, 175 00:09:39,520 --> 00:09:41,520 Speaker 1: So we don't really know if we're like looking at 176 00:09:41,559 --> 00:09:43,480 Speaker 1: most of the iceberg or just the tip of it. Right, 177 00:09:43,520 --> 00:09:46,280 Speaker 1: it's like a teenager. They feel like they've lived a 178 00:09:46,320 --> 00:09:50,360 Speaker 1: whole life and everything there's to know about everything. Everything 179 00:09:50,679 --> 00:09:53,679 Speaker 1: the universe knows nothing man, wait till it grows up. 180 00:09:53,920 --> 00:09:55,840 Speaker 1: But yeah, how sure are we that's the age of 181 00:09:55,880 --> 00:09:57,920 Speaker 1: the universe? I know we can we get it from, 182 00:09:57,960 --> 00:10:01,320 Speaker 1: you know, rewinding the trajectory of space and the expansion 183 00:10:01,360 --> 00:10:05,400 Speaker 1: of the universe, But is there any ambiguity about that? Like, 184 00:10:05,440 --> 00:10:08,360 Speaker 1: how sure we couldn't be that the universe didn't do 185 00:10:08,400 --> 00:10:11,160 Speaker 1: what we think it did, you know what I mean, like, 186 00:10:11,280 --> 00:10:15,120 Speaker 1: maybe it didn't compress smoothly from what we've see right now, Well, 187 00:10:15,160 --> 00:10:17,640 Speaker 1: we can see pretty well back in the history of 188 00:10:17,679 --> 00:10:20,520 Speaker 1: the universe. We don't just project, we can actually see 189 00:10:20,559 --> 00:10:23,600 Speaker 1: the history of the universe as we look out into space. 190 00:10:23,920 --> 00:10:26,360 Speaker 1: Remember that it takes light a long time to get 191 00:10:26,400 --> 00:10:29,640 Speaker 1: here from other places, so things that happened a long 192 00:10:29,720 --> 00:10:32,480 Speaker 1: time ago really far away, that light is just now 193 00:10:32,600 --> 00:10:35,680 Speaker 1: arriving at Earth. So we can literally see the history 194 00:10:35,679 --> 00:10:38,560 Speaker 1: of the universe and we can record its expansion, and 195 00:10:38,600 --> 00:10:41,559 Speaker 1: so we're pretty sure about the history of the expansion 196 00:10:41,600 --> 00:10:43,680 Speaker 1: of the universe. What we're not sure about is what 197 00:10:43,760 --> 00:10:47,000 Speaker 1: that represents. That moment fourteen billion years ago. Was it 198 00:10:47,120 --> 00:10:49,880 Speaker 1: really a beginning? Was it just like the start of 199 00:10:49,960 --> 00:10:52,840 Speaker 1: cycle number four and fifty two? Is there an infinite 200 00:10:52,920 --> 00:10:56,320 Speaker 1: number of cycles before that? Did the universe space assemble 201 00:10:56,440 --> 00:10:59,480 Speaker 1: from something else, some deeper quantum foam. We don't really 202 00:10:59,559 --> 00:11:02,240 Speaker 1: understand and whether we can call that a beginning, But 203 00:11:02,320 --> 00:11:04,920 Speaker 1: we know there was a special moment about fourteen billion 204 00:11:04,960 --> 00:11:08,079 Speaker 1: years ago. And how certain are we We haven't nailed 205 00:11:08,120 --> 00:11:10,880 Speaker 1: down to within about a hundred million years. Wow, that 206 00:11:11,040 --> 00:11:13,920 Speaker 1: is very specific. It's pretty specific, but it's also a 207 00:11:14,000 --> 00:11:16,559 Speaker 1: big range. You know, like if somebody said to you, hey, 208 00:11:16,559 --> 00:11:18,959 Speaker 1: I'll meet you tomorrow at three pm plus or mind 209 00:11:19,040 --> 00:11:21,760 Speaker 1: is a hundred million years, that wouldn't feel very specific, 210 00:11:21,800 --> 00:11:23,920 Speaker 1: but that would be hard to sing happy birthday about. 211 00:11:24,000 --> 00:11:26,199 Speaker 1: But if someone said, you know, you're a hundred years 212 00:11:26,240 --> 00:11:28,640 Speaker 1: old plus or mine is a couple of days, Yeah, yeah, 213 00:11:28,640 --> 00:11:30,840 Speaker 1: that's true. But I guess my question is how far 214 00:11:30,920 --> 00:11:35,040 Speaker 1: back can we see, Like can we actually see things 215 00:11:35,040 --> 00:11:37,480 Speaker 1: back that long? Or is this is it all sort 216 00:11:37,520 --> 00:11:39,720 Speaker 1: of based on a projection? Now we can see that 217 00:11:39,800 --> 00:11:42,040 Speaker 1: far back in time. If you look at stuff near 218 00:11:42,120 --> 00:11:44,440 Speaker 1: our galaxy, you know, we're in the Milky Way, and 219 00:11:44,480 --> 00:11:48,440 Speaker 1: the neighboring galaxy, Andromeda, is like millions of light years away. 220 00:11:48,640 --> 00:11:51,199 Speaker 1: So when you're looking at Andromeda, you're seeing what happened, 221 00:11:51,200 --> 00:11:54,240 Speaker 1: what it looked like millions of years ago. That's the 222 00:11:54,280 --> 00:11:58,160 Speaker 1: closest galaxy, that's like our immediate neighbor, and that's millions 223 00:11:58,160 --> 00:12:00,520 Speaker 1: of light years away. Then if you look further out, 224 00:12:00,600 --> 00:12:04,520 Speaker 1: like billions of light years, you get to these big structures. 225 00:12:04,600 --> 00:12:08,559 Speaker 1: Because galaxies form themselves into superclusters, and those superclusters are 226 00:12:08,600 --> 00:12:12,880 Speaker 1: organized into sheets that encompass these vast voids, these bubbles, 227 00:12:13,120 --> 00:12:15,120 Speaker 1: and one of them, for example, is called the Sloane 228 00:12:15,360 --> 00:12:18,240 Speaker 1: Great Wall, one of the first of these really big 229 00:12:18,280 --> 00:12:21,160 Speaker 1: structures to be discovered, and it's about a billion light 230 00:12:21,240 --> 00:12:24,280 Speaker 1: years away. A great wall of stars or galaxies, a 231 00:12:24,360 --> 00:12:28,200 Speaker 1: great wall of galaxy superclusters, right, So stars are formed 232 00:12:28,240 --> 00:12:32,240 Speaker 1: into galaxies, galaxies are formed into clusters, Galaxy clusters are 233 00:12:32,240 --> 00:12:36,520 Speaker 1: formed into superclusters, and then those are organized into these walls, 234 00:12:36,640 --> 00:12:39,760 Speaker 1: these sheets that wrap around these bubbles. I wonder who 235 00:12:39,760 --> 00:12:43,000 Speaker 1: paid for that, Danny. It's a lot of dry wall 236 00:12:43,040 --> 00:12:45,880 Speaker 1: and a lot of paint. Who picked those colors? Right? 237 00:12:45,920 --> 00:12:48,839 Speaker 1: With their galactic arguments about which shade of green or 238 00:12:48,840 --> 00:12:51,000 Speaker 1: which shade of red to burn, which spectrum of the 239 00:12:51,240 --> 00:12:54,680 Speaker 1: electromagnetic radiation it's going to give off, So that that's 240 00:12:54,800 --> 00:12:57,559 Speaker 1: a billion light years away. That's billion light years away, 241 00:12:57,720 --> 00:12:59,680 Speaker 1: and then we can look further out, and it becomes 242 00:12:59,679 --> 00:13:02,040 Speaker 1: hard earned harder to look further out because these things 243 00:13:02,040 --> 00:13:04,800 Speaker 1: are more distant, and so you need more powerful telescopes, 244 00:13:05,040 --> 00:13:07,640 Speaker 1: or you need to focus those telescopes for a longer time. 245 00:13:08,120 --> 00:13:10,439 Speaker 1: And that's like the reason we don't have a great 246 00:13:10,559 --> 00:13:13,480 Speaker 1: map of the entire universe so far is just that 247 00:13:13,480 --> 00:13:16,160 Speaker 1: that light is distant and dim, and so you need 248 00:13:16,240 --> 00:13:18,720 Speaker 1: a lot of telescopes looking at it. But we do 249 00:13:18,840 --> 00:13:22,520 Speaker 1: see some individual galaxies, like the hubble points itself in 250 00:13:22,600 --> 00:13:25,240 Speaker 1: one direction of space and just sort of like accumulates 251 00:13:25,240 --> 00:13:28,080 Speaker 1: photons for days and days and days. Then you can 252 00:13:28,080 --> 00:13:31,480 Speaker 1: see the dimmest galaxies, the ones where photons are arriving 253 00:13:31,720 --> 00:13:34,600 Speaker 1: most rarely because they've spread out through the whole universe. 254 00:13:35,120 --> 00:13:37,560 Speaker 1: And there we can see galaxies that are like more 255 00:13:37,600 --> 00:13:41,440 Speaker 1: than thirteen billion light years away. Wow, that's almost the 256 00:13:41,480 --> 00:13:43,880 Speaker 1: age of the universe. It's almost the age of the universe, 257 00:13:43,920 --> 00:13:46,599 Speaker 1: which means something amazing and fascinating, right. It means that 258 00:13:46,720 --> 00:13:50,600 Speaker 1: galaxies formed very early on in the universe. For example, 259 00:13:50,640 --> 00:13:55,040 Speaker 1: the oldest known galaxy is one called g n Z eleven. 260 00:13:55,120 --> 00:13:59,160 Speaker 1: It's thirteen point four billion light years away. That means 261 00:13:59,160 --> 00:14:02,160 Speaker 1: that it's formed just a few hundred million years after 262 00:14:02,200 --> 00:14:04,760 Speaker 1: the start of the whole universe. Well, and the images 263 00:14:04,840 --> 00:14:09,360 Speaker 1: we're seeing of that galaxy, it looks like it did 264 00:14:09,559 --> 00:14:13,120 Speaker 1: thirteen billion years ago, right, Yes, we're seeing baby pictures 265 00:14:13,320 --> 00:14:15,840 Speaker 1: of that galaxy, Like we don't know what's going on 266 00:14:15,920 --> 00:14:19,080 Speaker 1: with that galaxy today. Does it even still exist, did 267 00:14:19,120 --> 00:14:20,880 Speaker 1: it leave home, did it get a job, did it 268 00:14:20,960 --> 00:14:22,800 Speaker 1: have a big argument with his parents? We don't know, 269 00:14:23,240 --> 00:14:26,160 Speaker 1: But the baby pictures are what are arriving now at Earth. 270 00:14:26,360 --> 00:14:28,960 Speaker 1: And if we waited another ten billion years or so, 271 00:14:29,240 --> 00:14:32,040 Speaker 1: we would see the future of that galaxy, what happened 272 00:14:32,080 --> 00:14:35,120 Speaker 1: to it, and everything that subsequently occurred. But right now 273 00:14:35,160 --> 00:14:38,000 Speaker 1: we're only seeing the original light that left thirteen billion 274 00:14:38,080 --> 00:14:39,680 Speaker 1: years and when it was and it looks like a 275 00:14:39,720 --> 00:14:42,880 Speaker 1: fully formed galaxy, like you can see the structure in it. 276 00:14:43,000 --> 00:14:45,040 Speaker 1: And even though it's that young, what I mean is 277 00:14:45,160 --> 00:14:47,600 Speaker 1: it doesn't look lumpy and wrinkled like a baby. It 278 00:14:47,680 --> 00:14:50,120 Speaker 1: doesn't look lumpy and wrinkled like galaxy in the very 279 00:14:50,120 --> 00:14:53,000 Speaker 1: early universe do look different than galaxies today. A lot 280 00:14:53,080 --> 00:14:55,840 Speaker 1: of galaxies we have today are really big because they're 281 00:14:55,840 --> 00:14:59,640 Speaker 1: the product of galaxy mergers. Many galaxies come together in 282 00:14:59,720 --> 00:15:02,240 Speaker 1: a lot out of the spiral galaxies are the product 283 00:15:02,280 --> 00:15:05,120 Speaker 1: of the mergers of several galaxies. So this looks like 284 00:15:05,160 --> 00:15:07,760 Speaker 1: a younger galaxy and it's a great way to study 285 00:15:07,840 --> 00:15:11,680 Speaker 1: the very early universe. Like these infrared telescopes that we 286 00:15:11,760 --> 00:15:13,520 Speaker 1: have and that we're sending up soon are going to 287 00:15:13,560 --> 00:15:15,760 Speaker 1: be great at looking at this light from the really 288 00:15:15,800 --> 00:15:19,440 Speaker 1: really oldest galaxies, the ones that don't glow as much. So, yeah, 289 00:15:19,440 --> 00:15:21,880 Speaker 1: we can use this to study galaxies at the very 290 00:15:21,880 --> 00:15:23,600 Speaker 1: early age. And they do look a little different, like 291 00:15:23,640 --> 00:15:26,080 Speaker 1: galaxies looked different in the very beginning of the universe 292 00:15:26,120 --> 00:15:28,640 Speaker 1: than they do today. You see. I guess the question is, 293 00:15:28,720 --> 00:15:31,560 Speaker 1: and have we seen any stars that old or I 294 00:15:31,560 --> 00:15:33,440 Speaker 1: guess I mean, if you look at the galaxy, you're 295 00:15:33,440 --> 00:15:35,480 Speaker 1: looking at the stars in it, so you're sort of 296 00:15:35,520 --> 00:15:38,800 Speaker 1: looking at really old stars too. Yeah, we are looking 297 00:15:38,800 --> 00:15:42,160 Speaker 1: at old stars. But there's sort of three populations of stars. 298 00:15:42,200 --> 00:15:45,440 Speaker 1: There's the stars that are around today, and most of 299 00:15:45,480 --> 00:15:49,200 Speaker 1: these have formed from the collapse of the previous generation 300 00:15:49,280 --> 00:15:52,680 Speaker 1: of stars, and those stars formed from the collapse of 301 00:15:52,680 --> 00:15:56,240 Speaker 1: the previous generation of stars. Remember, stars happen when you 302 00:15:56,280 --> 00:15:58,280 Speaker 1: have a bunch of gas and stuff gathered together by 303 00:15:58,280 --> 00:16:01,400 Speaker 1: gravity enough so that they burn. And we think that 304 00:16:01,480 --> 00:16:04,520 Speaker 1: the first generation of stars formed fairly early in the universe, 305 00:16:04,640 --> 00:16:07,280 Speaker 1: but they were really big, and really big stars burn 306 00:16:07,440 --> 00:16:10,440 Speaker 1: really really hot, and so they don't last for very long. 307 00:16:10,920 --> 00:16:13,360 Speaker 1: And so that population of stars we haven't ever seen. 308 00:16:13,760 --> 00:16:16,680 Speaker 1: We haven't seen any stars from that time. But if 309 00:16:16,680 --> 00:16:19,120 Speaker 1: we're seeing a galaxy from that time, aren't we seeing 310 00:16:19,160 --> 00:16:21,600 Speaker 1: the stars from that time too, Or are you saying 311 00:16:22,080 --> 00:16:25,240 Speaker 1: we haven't seen like an individual pinpoint of light that 312 00:16:25,440 --> 00:16:27,360 Speaker 1: is one of the oldest stars. We haven't seen an 313 00:16:27,360 --> 00:16:29,440 Speaker 1: individual pin point of light. But also we think that 314 00:16:29,480 --> 00:16:32,680 Speaker 1: this galaxy has stars from the second population. We think 315 00:16:32,720 --> 00:16:36,760 Speaker 1: that first population didn't live long enough in this galaxy. 316 00:16:37,040 --> 00:16:39,360 Speaker 1: It lived less than a billion years, less than a 317 00:16:39,360 --> 00:16:42,320 Speaker 1: billion years. Those stars did not last for a billion years. 318 00:16:42,360 --> 00:16:45,320 Speaker 1: They were really big and hot and burned very quickly, 319 00:16:45,640 --> 00:16:48,440 Speaker 1: so we haven't seen any direct evidence of those stars yet. 320 00:16:48,440 --> 00:16:51,600 Speaker 1: Those are called population three stars. Wow, they burned out 321 00:16:51,640 --> 00:16:54,000 Speaker 1: in less than a billion years, less than a billion years, 322 00:16:54,040 --> 00:16:57,280 Speaker 1: absolutely just out of hydrogen, just out of hygen and 323 00:16:57,440 --> 00:16:59,840 Speaker 1: the keys that they're really big and really big stars 324 00:17:00,120 --> 00:17:02,720 Speaker 1: burned really hot and really fast, and so those are 325 00:17:02,760 --> 00:17:05,800 Speaker 1: all gone. And that's an interesting point because those stars 326 00:17:05,800 --> 00:17:09,080 Speaker 1: were created a long time ago, but they're no longer around. 327 00:17:09,600 --> 00:17:11,879 Speaker 1: So they were created in the early universe, but they 328 00:17:11,880 --> 00:17:15,240 Speaker 1: don't exist anymore, so they're not really old because they're gone. 329 00:17:15,400 --> 00:17:18,720 Speaker 1: I see. So galaxy g n Z eleven is thirteen 330 00:17:18,760 --> 00:17:22,520 Speaker 1: point four billion light years away, which means it's thirteen 331 00:17:22,520 --> 00:17:25,639 Speaker 1: point four billion years old. So is that the oldest 332 00:17:25,680 --> 00:17:27,600 Speaker 1: thing in the universe? We don't know if it's thirteen 333 00:17:27,600 --> 00:17:30,320 Speaker 1: point four billion years old. We know it existed thirteen 334 00:17:30,359 --> 00:17:33,160 Speaker 1: point four billion years ago, we don't know what it's 335 00:17:33,200 --> 00:17:35,840 Speaker 1: doing today. Right. It's like if you look at a 336 00:17:35,840 --> 00:17:38,280 Speaker 1: baby picture from somebody from a hundred years ago, you 337 00:17:38,280 --> 00:17:40,720 Speaker 1: don't know if they lived till two or five or 338 00:17:40,760 --> 00:17:43,320 Speaker 1: a hundred. So they could be the oldest person alive 339 00:17:43,400 --> 00:17:45,359 Speaker 1: if they were still around today, but you don't know, 340 00:17:45,440 --> 00:17:48,720 Speaker 1: you're just looking at the baby picture. I see a 341 00:17:48,720 --> 00:17:50,639 Speaker 1: lot of people when they think about, you know, what 342 00:17:50,800 --> 00:17:52,600 Speaker 1: is the oldest thing in the universe, they are tempted 343 00:17:52,640 --> 00:17:56,240 Speaker 1: to think really far away, really distant in time. But 344 00:17:56,280 --> 00:17:58,480 Speaker 1: we don't know if those things are still around. I see, 345 00:17:58,520 --> 00:18:01,400 Speaker 1: we're asking what's the oldest thing that is still around? Yeah, 346 00:18:01,440 --> 00:18:03,399 Speaker 1: because you're not old if you didn't live very long. Right, 347 00:18:03,440 --> 00:18:06,160 Speaker 1: somebody was born two hundred years ago and died ten 348 00:18:06,200 --> 00:18:10,359 Speaker 1: minutes later, isn't the oldest person in the world? Right? Oh? Interesting, 349 00:18:10,560 --> 00:18:13,800 Speaker 1: I guess I guess what would happen? What could have happened? 350 00:18:13,800 --> 00:18:19,160 Speaker 1: To that galaxy. Like galaxies just don't disappear. Galaxies don't disappear, 351 00:18:19,400 --> 00:18:22,720 Speaker 1: that's true. They get absorbed into other galaxies sometimes or 352 00:18:22,720 --> 00:18:26,040 Speaker 1: they get torn apart by other galaxies that come near them. 353 00:18:26,240 --> 00:18:28,399 Speaker 1: You know, there can be a lot of gravitational turbulence, 354 00:18:28,800 --> 00:18:31,400 Speaker 1: so that galaxy may not exist on its own anymore 355 00:18:31,440 --> 00:18:34,400 Speaker 1: and may have been absorbed by collisions into other galaxies, 356 00:18:34,880 --> 00:18:37,560 Speaker 1: or it could have gone shredded, yeah, by other galaxies 357 00:18:37,560 --> 00:18:41,480 Speaker 1: coming nearby and the gravitational tidal forces. It's a dangerous universe. 358 00:18:41,520 --> 00:18:43,479 Speaker 1: When you send your galaxies out there into the wild, 359 00:18:43,680 --> 00:18:45,640 Speaker 1: you don't know what's going to happen. And make sure 360 00:18:45,680 --> 00:18:50,760 Speaker 1: they look both ways before crossing the universal streets. All right, 361 00:18:50,880 --> 00:18:54,480 Speaker 1: let's talk about what is still around and what might 362 00:18:54,520 --> 00:18:58,840 Speaker 1: be the oldest thing in the universe still alive today. 363 00:18:59,400 --> 00:19:14,040 Speaker 1: But first it's take a quick break. All right, we're 364 00:19:14,080 --> 00:19:17,639 Speaker 1: talking about what is the oldest thing in the universe, 365 00:19:17,920 --> 00:19:19,960 Speaker 1: and so Daniel, we were talking about a galaxy that 366 00:19:20,280 --> 00:19:24,359 Speaker 1: was around thirteen point four billion light years away, But 367 00:19:24,400 --> 00:19:28,680 Speaker 1: you're saying that's not necessarily something that is still around today, 368 00:19:28,840 --> 00:19:32,760 Speaker 1: meaning that like what we're looking at is stuff that 369 00:19:32,920 --> 00:19:36,400 Speaker 1: was in the past, but we can't tell if it's 370 00:19:36,400 --> 00:19:39,600 Speaker 1: still around today. Yeah exactly. We don't know what's going 371 00:19:39,680 --> 00:19:42,879 Speaker 1: on really far away right now because it's going to 372 00:19:43,000 --> 00:19:46,480 Speaker 1: take that light another thirteen billion years to get here. 373 00:19:46,920 --> 00:19:48,880 Speaker 1: So if we want to talk about what the oldest 374 00:19:48,880 --> 00:19:50,919 Speaker 1: thing in the universe is, we need to look at 375 00:19:50,920 --> 00:19:53,479 Speaker 1: stuff that's kind of nearby to us, that's kind of 376 00:19:53,520 --> 00:19:55,600 Speaker 1: close so it doesn't take the light so long to 377 00:19:55,680 --> 00:19:58,240 Speaker 1: get here, so we can see it that it's still around. 378 00:19:58,800 --> 00:20:00,879 Speaker 1: But it feels like a you know, like a loophole 379 00:20:01,000 --> 00:20:04,120 Speaker 1: or like a paradox almost, like you know, we can 380 00:20:04,160 --> 00:20:07,800 Speaker 1: only tell if it's old by looking at it, but 381 00:20:08,320 --> 00:20:11,119 Speaker 1: we can only confirm how old it is if the 382 00:20:11,280 --> 00:20:14,040 Speaker 1: light is old that we're seeing of it. Do you 383 00:20:14,040 --> 00:20:16,000 Speaker 1: know what I mean? Well, if there was something that 384 00:20:16,119 --> 00:20:20,320 Speaker 1: was created in the very early universe nearby and still around, 385 00:20:20,440 --> 00:20:23,400 Speaker 1: and we could somehow measure its age, then that could 386 00:20:23,400 --> 00:20:25,680 Speaker 1: be crowned as the oldest thing in the universe. It 387 00:20:25,720 --> 00:20:28,120 Speaker 1: wouldn't take light very long to get here from it 388 00:20:28,200 --> 00:20:32,240 Speaker 1: because it'd be nearby. I see. We have to see 389 00:20:32,280 --> 00:20:34,960 Speaker 1: something old, is what you're saying, Yes, exactly, and not 390 00:20:35,040 --> 00:20:36,920 Speaker 1: just a really old picture of it. Yeah, we want 391 00:20:37,000 --> 00:20:40,800 Speaker 1: something around now that's old, not just old information about 392 00:20:40,800 --> 00:20:43,119 Speaker 1: something that existed a long time ago, which might not 393 00:20:43,200 --> 00:20:46,040 Speaker 1: be around anymore. You see. It's not like you're trying 394 00:20:46,080 --> 00:20:50,240 Speaker 1: to ask, what is the oldest baby picture of a 395 00:20:50,320 --> 00:20:53,720 Speaker 1: person you can find. You're trying to ask like, who 396 00:20:53,800 --> 00:20:56,720 Speaker 1: is the oldest French lady living in an apartment that 397 00:20:56,800 --> 00:20:59,679 Speaker 1: we can talk to today? Exactly? And both are fascinating questions. 398 00:20:59,720 --> 00:21:02,120 Speaker 1: And I want to see the oldest baby picture ever. 399 00:21:02,200 --> 00:21:05,120 Speaker 1: That's actually a really cool question. What is the oldest 400 00:21:05,119 --> 00:21:08,120 Speaker 1: baby picture? Who was the first baby to ever be photographed? 401 00:21:08,119 --> 00:21:09,840 Speaker 1: I don't even know the answer to that. And that's 402 00:21:09,840 --> 00:21:12,480 Speaker 1: why we do look really far away to look back 403 00:21:12,520 --> 00:21:15,040 Speaker 1: in time, because we want to know the original history 404 00:21:15,160 --> 00:21:17,800 Speaker 1: of the universe. But that doesn't tell us who's still 405 00:21:17,800 --> 00:21:20,600 Speaker 1: around today. So yeah, I want to see the astrophysical 406 00:21:20,640 --> 00:21:23,720 Speaker 1: equivalent of the oldest French lady. All right, So let's 407 00:21:23,720 --> 00:21:26,440 Speaker 1: start in our neighborhood. I guess in our galaxy, what's 408 00:21:26,480 --> 00:21:29,720 Speaker 1: the oldest I don't know, star or cloud that we 409 00:21:29,760 --> 00:21:32,480 Speaker 1: can see. Yeah, things get pretty old right around in 410 00:21:32,520 --> 00:21:36,240 Speaker 1: our neighborhood. Now, our star is only about five billion 411 00:21:36,320 --> 00:21:39,400 Speaker 1: years old. It's formed just under five billion years ago 412 00:21:39,560 --> 00:21:42,359 Speaker 1: from collapse of a big cloud of gas and dust 413 00:21:42,440 --> 00:21:45,720 Speaker 1: and bits of other stars. Right, that's about five billion 414 00:21:45,800 --> 00:21:48,439 Speaker 1: years ago, But the Milky Way itself is much older, 415 00:21:48,440 --> 00:21:51,760 Speaker 1: and there are older stars right here in our Milky Way, 416 00:21:52,000 --> 00:21:55,320 Speaker 1: much much older. How old are we to, Well, what's 417 00:21:55,359 --> 00:21:57,840 Speaker 1: the oldest star we can see here in our galaxy? Yeah, 418 00:21:57,880 --> 00:22:00,240 Speaker 1: there's a star here that goes by the awesome aime 419 00:22:00,320 --> 00:22:04,639 Speaker 1: of h D one zero to eight three, and at 420 00:22:04,680 --> 00:22:08,120 Speaker 1: least it's you know, that's a big plus twenty years ago. 421 00:22:08,400 --> 00:22:10,679 Speaker 1: We're trying to upgrade it to four K but it 422 00:22:10,720 --> 00:22:12,720 Speaker 1: costs a lot of money and it has a really 423 00:22:12,840 --> 00:22:15,600 Speaker 1: weird age. So, you know, the universe is just under 424 00:22:15,640 --> 00:22:18,480 Speaker 1: fourteen billion years old, this star is fourteen and a 425 00:22:18,520 --> 00:22:22,119 Speaker 1: half billion years old, which is weird, Like, what, yeah, 426 00:22:22,200 --> 00:22:24,920 Speaker 1: how can the star be older than the universe. Well, 427 00:22:24,920 --> 00:22:27,440 Speaker 1: it turns out there's a big uncertainty on that measurement. 428 00:22:27,480 --> 00:22:30,879 Speaker 1: It's fourteen and a half plus or minus point eight 429 00:22:30,920 --> 00:22:34,280 Speaker 1: billion years, so it's almost a billion years of uncertainty. 430 00:22:34,640 --> 00:22:37,720 Speaker 1: But it's super wow. Wait, and it's right here in 431 00:22:37,760 --> 00:22:41,080 Speaker 1: our backyard. Yeah, it's only two hundred light years away. 432 00:22:41,240 --> 00:22:44,280 Speaker 1: It's like pretty close by. It's one of the closer 433 00:22:44,320 --> 00:22:47,960 Speaker 1: stars in our galaxy, and it's the oldest star we've 434 00:22:48,000 --> 00:22:53,000 Speaker 1: seen in the galaxy. Wow, or maybe ever? Is it possible? Ever? Yes, absolutely, 435 00:22:53,040 --> 00:22:55,320 Speaker 1: it's one of the oldest stars known in the universe. 436 00:22:55,320 --> 00:22:57,800 Speaker 1: Of course, it's much easier to measure the age of 437 00:22:57,840 --> 00:23:01,359 Speaker 1: stars in our galaxy than in other galaxies. But yeah, 438 00:23:01,560 --> 00:23:03,760 Speaker 1: it's one of the oldest stars in our galaxy and 439 00:23:03,880 --> 00:23:06,879 Speaker 1: in the universe it's crazy old. Yeah, because we we 440 00:23:06,920 --> 00:23:09,320 Speaker 1: can't really see stars in other galaxies, right, I mean, 441 00:23:09,440 --> 00:23:13,280 Speaker 1: unless it's like a supernova or something super duper bright. 442 00:23:13,440 --> 00:23:16,040 Speaker 1: But generally speaking, you know, most of the stars that 443 00:23:16,080 --> 00:23:19,040 Speaker 1: you've seen in the night sky are in the galaxy. Yeah, exactly. 444 00:23:19,280 --> 00:23:21,520 Speaker 1: You can if you have a very powerful telescope sometimes 445 00:23:21,520 --> 00:23:24,040 Speaker 1: resolve stars and other galaxies, as you say, if they're 446 00:23:24,119 --> 00:23:26,960 Speaker 1: very very bright. But most of the stars we're looking 447 00:23:27,000 --> 00:23:30,000 Speaker 1: at the constellations, for example, this is just the rest 448 00:23:30,000 --> 00:23:32,040 Speaker 1: of the Milky Way. We're embedded in it, and as 449 00:23:32,080 --> 00:23:34,199 Speaker 1: we look out into the night sky, those are the 450 00:23:34,240 --> 00:23:37,720 Speaker 1: stars we see. And this star here is really old 451 00:23:37,920 --> 00:23:41,359 Speaker 1: and it's lasted a long time because it's pretty small, 452 00:23:41,640 --> 00:23:44,560 Speaker 1: like these stars don't burn very quickly. A really big 453 00:23:44,600 --> 00:23:48,439 Speaker 1: star burns really fast, and a really small star burns 454 00:23:48,520 --> 00:23:50,639 Speaker 1: much slower, and so it can sort of like stretch 455 00:23:50,920 --> 00:23:54,760 Speaker 1: its fuel out much longer. It just sits there, simmering, 456 00:23:55,400 --> 00:23:59,840 Speaker 1: simmering and anger and being small. Exactly, it's grumpy and 457 00:24:00,119 --> 00:24:03,440 Speaker 1: even it literally comes from a previous generation of stars, 458 00:24:03,440 --> 00:24:07,400 Speaker 1: Like our sun is made out of the destroyed bits 459 00:24:07,440 --> 00:24:10,320 Speaker 1: of this second generation stars. So there was the first 460 00:24:10,320 --> 00:24:13,520 Speaker 1: generation that burned really quickly, then the second generation that 461 00:24:13,600 --> 00:24:16,440 Speaker 1: had a little bit of heavier metals in them from 462 00:24:16,440 --> 00:24:19,880 Speaker 1: the remnants of that first generation, and then our star 463 00:24:20,000 --> 00:24:23,160 Speaker 1: is born in the third generation of stars, the remnants 464 00:24:23,200 --> 00:24:26,280 Speaker 1: of the second generation. This one h D whatever is 465 00:24:26,320 --> 00:24:29,720 Speaker 1: actually still from that second generation of stars. It's still around, 466 00:24:29,720 --> 00:24:31,879 Speaker 1: and so it's it's pretty old. It's I feel like 467 00:24:31,920 --> 00:24:34,680 Speaker 1: it's a fourteen point five billion years old. It's almost 468 00:24:34,720 --> 00:24:37,280 Speaker 1: as old as the universe itself. Is it older than 469 00:24:37,320 --> 00:24:39,600 Speaker 1: the Milky Way, Then it's almost as old as the 470 00:24:39,680 --> 00:24:42,400 Speaker 1: universe itself. You're exactly right. We don't know if it's 471 00:24:42,440 --> 00:24:44,560 Speaker 1: older than the Milky Way. We know the Milky Way 472 00:24:44,600 --> 00:24:47,560 Speaker 1: is about thirteen and a half billion years old. It's 473 00:24:47,600 --> 00:24:50,840 Speaker 1: almost as old as the universe. It's a galaxy that 474 00:24:50,920 --> 00:24:54,080 Speaker 1: formed very very early on, so like it's as old 475 00:24:54,280 --> 00:24:57,760 Speaker 1: as that galaxy we talked about g n Z eleven 476 00:24:57,800 --> 00:25:00,399 Speaker 1: that's thirteen and a half billion light years away. We 477 00:25:00,440 --> 00:25:02,919 Speaker 1: have pictures of that one from when it was forming 478 00:25:02,960 --> 00:25:05,119 Speaker 1: the thirteen and a half billion years ago. But our 479 00:25:05,200 --> 00:25:08,480 Speaker 1: galaxy was also forming thirteen and a half billion years ago, 480 00:25:09,080 --> 00:25:12,080 Speaker 1: so we live in an ancient neighborhood. It's almost like 481 00:25:12,119 --> 00:25:14,720 Speaker 1: the star was around when the galaxy was formed, when 482 00:25:14,720 --> 00:25:17,000 Speaker 1: the Milky Way was being born. Yeah, and you know, 483 00:25:17,080 --> 00:25:19,760 Speaker 1: there's a bit of a definitional question there because galaxies 484 00:25:19,800 --> 00:25:23,520 Speaker 1: are formed from stars as they come together. And we 485 00:25:23,560 --> 00:25:25,520 Speaker 1: talked to the podcast once about how the structure of 486 00:25:25,520 --> 00:25:27,960 Speaker 1: the universe formed and how it's influenced by dark matter, 487 00:25:28,240 --> 00:25:30,960 Speaker 1: and we're pretty sure that the structure forms bottom up, 488 00:25:31,119 --> 00:25:33,679 Speaker 1: that you know, stars collapse and then are gathered together 489 00:25:33,800 --> 00:25:37,920 Speaker 1: into galaxies rather than like huge sheets of matter breaking 490 00:25:37,960 --> 00:25:41,119 Speaker 1: off into chunks which then separate into galaxies and separate 491 00:25:41,160 --> 00:25:44,359 Speaker 1: into stars. So we think it's stars before galaxies that 492 00:25:44,520 --> 00:25:47,640 Speaker 1: like galaxies are formed out of stars that have coalesced 493 00:25:47,800 --> 00:25:51,119 Speaker 1: from early blobs of gas and dust. All right, So 494 00:25:51,160 --> 00:25:53,600 Speaker 1: this planet may have been around when all that was 495 00:25:53,680 --> 00:25:56,960 Speaker 1: happening in our galaxy. But I guess the question is, 496 00:25:57,000 --> 00:26:00,159 Speaker 1: how do we know how old this star is? Mean, 497 00:26:00,200 --> 00:26:04,359 Speaker 1: it's just a big ball of simmering resentment or fire. 498 00:26:04,800 --> 00:26:06,679 Speaker 1: How can you tell how old it is? I mean, 499 00:26:06,680 --> 00:26:09,440 Speaker 1: does it look different than it did billion years ago? 500 00:26:09,640 --> 00:26:11,879 Speaker 1: You can tell by how well it plays scrabble. Actually 501 00:26:11,960 --> 00:26:15,040 Speaker 1: that's pretty good predictor. You know, it's really hard to 502 00:26:15,119 --> 00:26:19,240 Speaker 1: measure the age of one star. It's very difficult because stars, 503 00:26:19,359 --> 00:26:22,280 Speaker 1: when they burn, like our sun, look mostly the same 504 00:26:22,480 --> 00:26:25,080 Speaker 1: from most of their lifetime. Like our son. We expect 505 00:26:25,119 --> 00:26:27,720 Speaker 1: to have about a ten billion year lifetime. We're about 506 00:26:27,720 --> 00:26:29,840 Speaker 1: halfway through it, and it's not going to look very 507 00:26:29,880 --> 00:26:33,160 Speaker 1: different now and in a billion years and in four 508 00:26:33,200 --> 00:26:35,639 Speaker 1: billion years. It looks pretty different at the very beginning 509 00:26:35,680 --> 00:26:38,360 Speaker 1: as it's forming, and it's pretty exciting stuff happens at 510 00:26:38,400 --> 00:26:41,960 Speaker 1: the end when it's fizzling out. But in that intermediate time, 511 00:26:42,040 --> 00:26:44,399 Speaker 1: it's really hard to nail down the age of a 512 00:26:44,440 --> 00:26:47,160 Speaker 1: star just by looking at it. But wait, how so then, 513 00:26:47,160 --> 00:26:49,720 Speaker 1: how can we tell how old our star is? Yeah? So, 514 00:26:49,840 --> 00:26:52,119 Speaker 1: mostly the way we tell the age of stars is 515 00:26:52,160 --> 00:26:54,880 Speaker 1: not by telling the age of individual stars. But by 516 00:26:54,920 --> 00:26:58,360 Speaker 1: looking at star clusters groups of stars, because we think 517 00:26:58,400 --> 00:27:01,200 Speaker 1: that they are formed together, that like these big clouds 518 00:27:01,240 --> 00:27:04,280 Speaker 1: of gas and dust smashed together or something happens to 519 00:27:04,320 --> 00:27:07,200 Speaker 1: trigger star formation, and you get these clusters of stars 520 00:27:07,240 --> 00:27:09,680 Speaker 1: that are all the same age. Now, you can't tell 521 00:27:09,720 --> 00:27:12,440 Speaker 1: the individual age of a starter easily, so how could 522 00:27:12,480 --> 00:27:14,720 Speaker 1: you tell the age of a whole cluster. Well, the 523 00:27:14,760 --> 00:27:16,919 Speaker 1: cool thing about a cluster is that it has stars 524 00:27:16,920 --> 00:27:20,520 Speaker 1: of different sizes, as bigger ones and smaller ones. So 525 00:27:20,640 --> 00:27:22,520 Speaker 1: if it gets old enough, then you start to see 526 00:27:22,520 --> 00:27:24,960 Speaker 1: a few of those stars burn out. They go from 527 00:27:25,000 --> 00:27:27,120 Speaker 1: like being a normal star to being like a red 528 00:27:27,160 --> 00:27:30,080 Speaker 1: giant in the last phases of their life. And when 529 00:27:30,119 --> 00:27:32,040 Speaker 1: that happens, you can measure the age of a star. 530 00:27:32,160 --> 00:27:34,800 Speaker 1: You can measure it when it's starting to fizzle out. Oh, 531 00:27:34,880 --> 00:27:36,720 Speaker 1: I see, but you don't actually see it fizzle out. 532 00:27:36,760 --> 00:27:38,760 Speaker 1: You just see like if you see a red giant. 533 00:27:38,800 --> 00:27:41,359 Speaker 1: You know that red giants don't last very long, so 534 00:27:41,400 --> 00:27:44,160 Speaker 1: it must have happened recently. Yeah, exactly. So you look 535 00:27:44,160 --> 00:27:45,600 Speaker 1: at a whole group of stars and you look at 536 00:27:45,600 --> 00:27:47,639 Speaker 1: this population, you say, oh, some of them have started 537 00:27:47,640 --> 00:27:50,680 Speaker 1: to fall off onto this red giant track, and once 538 00:27:50,720 --> 00:27:52,560 Speaker 1: you look at that star, you can see how big 539 00:27:52,640 --> 00:27:55,080 Speaker 1: it is, and then you can tell how bright it's burning, 540 00:27:55,119 --> 00:27:57,880 Speaker 1: like how fast it was using its fuel, And now 541 00:27:57,920 --> 00:27:59,920 Speaker 1: that you know it's turned off on the Red Giant track, 542 00:28:00,040 --> 00:28:02,080 Speaker 1: give an idea of how long it took to burn 543 00:28:02,119 --> 00:28:04,679 Speaker 1: that fuel, so you can figure out like, okay, it 544 00:28:04,800 --> 00:28:07,560 Speaker 1: must be seven billion years old or something, and then 545 00:28:07,600 --> 00:28:09,200 Speaker 1: you can look at the whole cluster and say, oh, 546 00:28:09,240 --> 00:28:11,560 Speaker 1: the whole cluster is about seven billion years old. Even 547 00:28:11,600 --> 00:28:14,560 Speaker 1: though most of the stars individually you can't really tell 548 00:28:14,560 --> 00:28:18,159 Speaker 1: anything about them because they're just burning happily. Still. Clusters 549 00:28:18,200 --> 00:28:22,600 Speaker 1: do have signs of aging, but stars don't. So then 550 00:28:22,640 --> 00:28:24,880 Speaker 1: how do we know that this particular star HD one 551 00:28:24,920 --> 00:28:27,520 Speaker 1: four oh to eight three is fourteen and a half 552 00:28:27,880 --> 00:28:30,440 Speaker 1: billion years old? Well, we don't know it very well. 553 00:28:30,480 --> 00:28:32,560 Speaker 1: And the reason is that it's not part of a cluster. 554 00:28:32,600 --> 00:28:34,920 Speaker 1: It's just like out there on its own, called these 555 00:28:35,000 --> 00:28:38,240 Speaker 1: field stars. They're just like loners, you know, and a 556 00:28:38,320 --> 00:28:40,360 Speaker 1: loner star it's really hard to tell its age. We 557 00:28:40,440 --> 00:28:42,680 Speaker 1: have some ways of doing it, like we have models 558 00:28:43,000 --> 00:28:45,880 Speaker 1: for how stars age as they get older. You know, 559 00:28:46,000 --> 00:28:49,880 Speaker 1: they change their spin rate for example, or the color 560 00:28:50,040 --> 00:28:53,760 Speaker 1: changes a little bit. But these methods are much less reliable, 561 00:28:53,840 --> 00:28:56,680 Speaker 1: much less precise than looking at a whole star cluster. 562 00:28:56,960 --> 00:28:59,840 Speaker 1: And that's why there's so much uncertainty, Like fourteen and 563 00:28:59,880 --> 00:29:03,600 Speaker 1: a half plus or minus point eight is a big uncertainty, 564 00:29:03,600 --> 00:29:05,280 Speaker 1: And the reason is that it's by itself. We have 565 00:29:05,360 --> 00:29:07,360 Speaker 1: to use these models and make a lot of theoretical 566 00:29:07,440 --> 00:29:10,640 Speaker 1: assumptions about how stars look. So that's why we're not 567 00:29:10,680 --> 00:29:13,680 Speaker 1: so sure. I see, I see. We just think it's 568 00:29:13,720 --> 00:29:16,880 Speaker 1: fourteen and a halfpenion years old from what we can 569 00:29:16,920 --> 00:29:18,800 Speaker 1: tell of it. Yeah, you know, we see a bunch 570 00:29:18,800 --> 00:29:20,720 Speaker 1: of wrinkles and we think, wow, that looks like an 571 00:29:20,760 --> 00:29:22,720 Speaker 1: old star. If it was hanging out with all of 572 00:29:22,720 --> 00:29:24,800 Speaker 1: its friends and half of them had died already, would 573 00:29:24,800 --> 00:29:27,920 Speaker 1: be more confident that it was really old. But we 574 00:29:28,040 --> 00:29:29,840 Speaker 1: can't really pin it down as well. Maybe that's a 575 00:29:29,880 --> 00:29:32,360 Speaker 1: secret to old age. Daniel don't don't have any friends. 576 00:29:33,760 --> 00:29:38,520 Speaker 1: That's a secret to looking old. Maybe that's the track 577 00:29:38,640 --> 00:29:42,400 Speaker 1: I'm on. All right, Well, let's get into bigger things 578 00:29:42,400 --> 00:29:46,080 Speaker 1: and maybe older things in our galaxy. But first let's 579 00:29:46,080 --> 00:29:59,600 Speaker 1: take another quick break. All right, we're talking about the 580 00:29:59,640 --> 00:30:02,760 Speaker 1: old thing in the universe, and Daniel. Why I think 581 00:30:02,760 --> 00:30:06,640 Speaker 1: we mean like an organization of matter, because there is 582 00:30:06,760 --> 00:30:09,280 Speaker 1: matter in the universe that is still around from the 583 00:30:09,320 --> 00:30:12,560 Speaker 1: Big Bang, right, Like, like protons and electrons were all 584 00:30:12,680 --> 00:30:14,640 Speaker 1: sort of born in the Big Bang. Yeah, there's a 585 00:30:14,680 --> 00:30:16,560 Speaker 1: lot of stuff left over from the Big Bang. And 586 00:30:16,560 --> 00:30:19,320 Speaker 1: so if you call protons a thing or electrons a thing, 587 00:30:19,680 --> 00:30:22,200 Speaker 1: then some of those could be almost as old as 588 00:30:22,240 --> 00:30:25,440 Speaker 1: the universe. Remember the very first moments of the universe, 589 00:30:25,480 --> 00:30:28,200 Speaker 1: there weren't protons and electrons and particles, and the way 590 00:30:28,240 --> 00:30:30,800 Speaker 1: we think about them, things were so hot and so 591 00:30:30,880 --> 00:30:34,200 Speaker 1: dense and so crazy. There was so much energy slashing 592 00:30:34,240 --> 00:30:37,720 Speaker 1: around in the field that didn't really like get discretized 593 00:30:37,840 --> 00:30:40,640 Speaker 1: and localized into what we think of now as particles. 594 00:30:40,960 --> 00:30:42,880 Speaker 1: It's like you had an ocean. You don't think about 595 00:30:42,880 --> 00:30:45,880 Speaker 1: any individual marine drops, right. And for the most part, 596 00:30:45,920 --> 00:30:48,959 Speaker 1: electrons and protons, which are made out of orcs, they 597 00:30:48,960 --> 00:30:52,120 Speaker 1: don't really disappear or appear all of a sudden, right Like. 598 00:30:52,160 --> 00:30:54,760 Speaker 1: They hang around. They might change from being a star 599 00:30:54,920 --> 00:30:58,160 Speaker 1: to being dust to being people. But pretty much the 600 00:30:58,240 --> 00:31:00,840 Speaker 1: things were made out of have been around maybe since 601 00:31:00,840 --> 00:31:03,880 Speaker 1: the Big Bang, Yeah, exactly. Now you can annihilate a 602 00:31:03,880 --> 00:31:06,680 Speaker 1: proton or an electron. We smash a lot of protons 603 00:31:06,720 --> 00:31:09,520 Speaker 1: every day at the Large Adron Collider, and electrons. If 604 00:31:09,520 --> 00:31:11,680 Speaker 1: they hit a positron, they can turn into a photon, 605 00:31:11,880 --> 00:31:14,320 Speaker 1: so it's possible to kill them. They're not immortal in 606 00:31:14,360 --> 00:31:16,880 Speaker 1: that way, but on their own they are a stable. 607 00:31:16,960 --> 00:31:19,360 Speaker 1: You have an electron just sitting in space, it will 608 00:31:19,400 --> 00:31:22,120 Speaker 1: stay there as an electron forever, and the same we 609 00:31:22,200 --> 00:31:24,680 Speaker 1: think for a proton. So you're right that some of 610 00:31:24,720 --> 00:31:28,000 Speaker 1: the protons and electrons in us may be as old 611 00:31:28,120 --> 00:31:30,640 Speaker 1: as any particle in the universe. That could be the 612 00:31:30,680 --> 00:31:34,160 Speaker 1: first generation of particles ever made. Can you imagine me 613 00:31:34,160 --> 00:31:38,440 Speaker 1: in a proton that old, like you've survived fifteen billion 614 00:31:38,520 --> 00:31:41,280 Speaker 1: years and then only to be sucked into a particle 615 00:31:41,320 --> 00:31:44,560 Speaker 1: collider by some physicists and then be killed that way. 616 00:31:44,720 --> 00:31:46,720 Speaker 1: I don't know. I'd rather be in an excitement of 617 00:31:46,760 --> 00:31:48,840 Speaker 1: a particle collider than like end up as somebody's tone 618 00:31:48,880 --> 00:31:53,360 Speaker 1: nail or both. I mean, if you get to do both, 619 00:31:53,400 --> 00:31:55,240 Speaker 1: that might be better. Well, we are working on a 620 00:31:55,240 --> 00:31:57,520 Speaker 1: tonail collider, so yeah, you could be both. That would 621 00:31:57,560 --> 00:32:05,920 Speaker 1: be quite a feat. Oh, I don't know what to 622 00:32:05,960 --> 00:32:08,160 Speaker 1: say to that. You just put your foot in my mouth. 623 00:32:09,480 --> 00:32:11,680 Speaker 1: All right, So that star might be the oldest thing 624 00:32:11,720 --> 00:32:14,440 Speaker 1: that we know about, or it may not, because there's 625 00:32:14,480 --> 00:32:17,720 Speaker 1: a big uncertainty about it. But what else we think 626 00:32:17,800 --> 00:32:20,720 Speaker 1: is maybe as old or older than this star in 627 00:32:20,760 --> 00:32:23,760 Speaker 1: our galaxy? Well, there are black holes, right. Black holes 628 00:32:23,760 --> 00:32:27,800 Speaker 1: are fascinating mysterious objects we'd like to understand better. There 629 00:32:27,840 --> 00:32:30,640 Speaker 1: are ones at the centers of our galaxy. There are 630 00:32:30,720 --> 00:32:33,880 Speaker 1: individuals stellar black holes floating around. And then there's the 631 00:32:33,920 --> 00:32:38,160 Speaker 1: possibility that there are primordial black holes. Black holes formed 632 00:32:38,400 --> 00:32:41,240 Speaker 1: in the first moments of the Big Bang, maybe even 633 00:32:41,320 --> 00:32:45,240 Speaker 1: before protons were made. Wow, wait, what black hole? That's 634 00:32:45,360 --> 00:32:48,479 Speaker 1: that are older than particles, older than particles. We had 635 00:32:48,480 --> 00:32:52,280 Speaker 1: a whole fun episode about primordial black holes. And remember 636 00:32:52,320 --> 00:32:55,240 Speaker 1: that the very early universe things were hot and dense, 637 00:32:55,560 --> 00:32:57,400 Speaker 1: and we talked about why there wasn't just like a 638 00:32:57,440 --> 00:33:00,280 Speaker 1: whole universe size black hole in the very big ending, 639 00:33:00,480 --> 00:33:03,720 Speaker 1: because you need like localized pockets of over density for 640 00:33:03,800 --> 00:33:06,000 Speaker 1: stuff to gather together to make a black hole. You 641 00:33:06,000 --> 00:33:08,400 Speaker 1: can't just have the whole universe be a black hole. 642 00:33:08,640 --> 00:33:10,880 Speaker 1: But after things spread out a little bit, that's exactly 643 00:33:10,880 --> 00:33:13,480 Speaker 1: what you had. You had pockets of very dense matter 644 00:33:13,760 --> 00:33:16,200 Speaker 1: that were more dense than the neighboring stuff, and so 645 00:33:16,240 --> 00:33:19,120 Speaker 1: it's possible that some of those formed black holes, which 646 00:33:19,160 --> 00:33:22,080 Speaker 1: could still be around today. Nobody's ever seen one of 647 00:33:22,120 --> 00:33:25,560 Speaker 1: these black holes, these primordial ones, but we can't prove 648 00:33:25,600 --> 00:33:28,080 Speaker 1: that they don't exist, and some people think they might 649 00:33:28,120 --> 00:33:30,520 Speaker 1: even be a good candidate for dark matter. Wait, meaning 650 00:33:30,560 --> 00:33:32,400 Speaker 1: that the black hole is made out of dark matter. 651 00:33:32,600 --> 00:33:36,440 Speaker 1: That dark matter is made out of black holes, right right, 652 00:33:36,640 --> 00:33:39,240 Speaker 1: like little tiny black holes floating around in space. Yeah, 653 00:33:39,240 --> 00:33:41,440 Speaker 1: because we know there's more stuff out there that has 654 00:33:41,480 --> 00:33:44,760 Speaker 1: gravity that we can't explain, and black holes fit the 655 00:33:44,800 --> 00:33:47,959 Speaker 1: bill because they are massive and they are dark, and 656 00:33:48,000 --> 00:33:50,320 Speaker 1: they would have been created before the quarks, and so 657 00:33:50,560 --> 00:33:52,959 Speaker 1: they would explain why these things can't be made out 658 00:33:53,000 --> 00:33:55,760 Speaker 1: of quarks. So it's a really fun idea that primordial 659 00:33:55,800 --> 00:33:58,240 Speaker 1: black holes could be out there. In fact, there's even 660 00:33:58,280 --> 00:34:01,600 Speaker 1: this idea that there's another planet in our Solar system 661 00:34:01,600 --> 00:34:04,880 Speaker 1: because people have seen weird tugs on Neptune and Uranus 662 00:34:05,080 --> 00:34:08,120 Speaker 1: that they can't explain without some kind of dark, massive 663 00:34:08,160 --> 00:34:11,880 Speaker 1: object out there tugging on them gravitationally, and some folks 664 00:34:11,920 --> 00:34:14,960 Speaker 1: think it might be a primordial black hole. And remember 665 00:34:15,000 --> 00:34:17,680 Speaker 1: these things are small, Like a black hole with the 666 00:34:17,719 --> 00:34:19,880 Speaker 1: mass of a planet would be about the size of 667 00:34:19,880 --> 00:34:22,439 Speaker 1: a tennis ball, so it would be pretty easy to miss. 668 00:34:22,440 --> 00:34:24,799 Speaker 1: You don't want to play tennis with that unless you 669 00:34:24,840 --> 00:34:29,239 Speaker 1: have a pretty good racket. You can really hit a 670 00:34:29,360 --> 00:34:33,239 Speaker 1: planet mass ball very hard. Anyway, just like smashing your 671 00:34:33,239 --> 00:34:35,280 Speaker 1: tennis racket on the ground, it doesn't really do anything 672 00:34:35,360 --> 00:34:38,080 Speaker 1: to the trajectory of the planet. And so this primordial 673 00:34:38,120 --> 00:34:40,640 Speaker 1: black hole could be in our in our own solar system, 674 00:34:40,719 --> 00:34:43,560 Speaker 1: so like maybe the oldest thing in our universe, we 675 00:34:43,560 --> 00:34:45,960 Speaker 1: could be really nearby. It could be pulling on us 676 00:34:46,080 --> 00:34:48,000 Speaker 1: right now. It could be in fact. But one of 677 00:34:48,000 --> 00:34:50,360 Speaker 1: the really interesting things about black holes is that you 678 00:34:50,440 --> 00:34:54,719 Speaker 1: cannot tell their age. Remember, black holes hide information that 679 00:34:54,840 --> 00:34:57,879 Speaker 1: give out nothing about what's inside them. The only thing 680 00:34:57,920 --> 00:35:00,279 Speaker 1: you can know about a black hole is it's mas us, 681 00:35:00,600 --> 00:35:03,600 Speaker 1: it's spin, and its electric charge. And that means that 682 00:35:03,640 --> 00:35:05,920 Speaker 1: it's impossible to know the age of a black hole, 683 00:35:05,960 --> 00:35:08,120 Speaker 1: the same way you can't know the age of a proton. 684 00:35:08,640 --> 00:35:12,560 Speaker 1: Black Holes are like quantum mechanically indistinguishable from each other. 685 00:35:12,760 --> 00:35:15,759 Speaker 1: If they have the same mass, charge and spin. They're 686 00:35:15,760 --> 00:35:18,520 Speaker 1: like the canoes of the universe can't tell how old 687 00:35:18,560 --> 00:35:23,160 Speaker 1: they are. That's right, yeah, exactly, though his career is 688 00:35:23,200 --> 00:35:26,040 Speaker 1: not exactly a black hole. But you know, if you 689 00:35:26,120 --> 00:35:28,359 Speaker 1: form a black hole yesterday and you form a black 690 00:35:28,360 --> 00:35:30,760 Speaker 1: hole a billion years ago with the same amount of mass, 691 00:35:30,800 --> 00:35:33,839 Speaker 1: they will look totally identical. There's no way to get 692 00:35:33,840 --> 00:35:36,960 Speaker 1: any information but when that stuff went into the black hole, 693 00:35:37,239 --> 00:35:40,160 Speaker 1: which is pretty fascinating. But it also means that even 694 00:35:40,200 --> 00:35:42,480 Speaker 1: if we saw a primordial black hole, we wouldn't know 695 00:35:42,560 --> 00:35:46,360 Speaker 1: how old it was. And but and again these are theoretical. 696 00:35:46,360 --> 00:35:49,400 Speaker 1: We haven't seen any of these. But what about the 697 00:35:49,440 --> 00:35:51,759 Speaker 1: ones like at the center of galaxies, like at the 698 00:35:51,800 --> 00:35:54,719 Speaker 1: center of our galaxies? Are those made out of primordial 699 00:35:54,760 --> 00:35:57,200 Speaker 1: black holes or do we know for sure they were 700 00:35:57,239 --> 00:36:00,520 Speaker 1: formed more recently. We don't know. And one of the 701 00:36:00,560 --> 00:36:03,280 Speaker 1: mysteries of those black holes is that they're really, really big. 702 00:36:03,320 --> 00:36:06,160 Speaker 1: We can't explain how they got so big so fast. 703 00:36:06,480 --> 00:36:10,240 Speaker 1: Our models of galaxy formation suggests that those black holes 704 00:36:10,239 --> 00:36:12,880 Speaker 1: should be smaller. One way to make them bigger. To 705 00:36:12,960 --> 00:36:15,759 Speaker 1: explain the mystery of super massive black holes is if 706 00:36:15,800 --> 00:36:19,120 Speaker 1: they were actually seated with pretty big primordial black holes 707 00:36:19,200 --> 00:36:21,440 Speaker 1: from the Big Bang. But that's just an idea we 708 00:36:21,480 --> 00:36:24,360 Speaker 1: don't understand. But if they were formed just from like 709 00:36:24,480 --> 00:36:27,120 Speaker 1: stars and gas and dust collapsing into a black hole, 710 00:36:27,360 --> 00:36:30,680 Speaker 1: which is possible, then there would be as old as 711 00:36:30,680 --> 00:36:34,279 Speaker 1: our galaxy and probably less old than the stars in 712 00:36:34,320 --> 00:36:37,840 Speaker 1: our galaxy. Yeah, like, we know how old our galaxy is, 713 00:36:37,920 --> 00:36:40,080 Speaker 1: but do we know of other galaxies out there that 714 00:36:40,160 --> 00:36:42,319 Speaker 1: might be older than ours? Well, we do live in 715 00:36:42,400 --> 00:36:45,239 Speaker 1: one of the oldest galaxies, one of the oldest neighborhoods 716 00:36:45,280 --> 00:36:47,640 Speaker 1: in the universe, and as we look at the galaxies 717 00:36:47,680 --> 00:36:50,480 Speaker 1: around us, we see that they're all pretty old. The 718 00:36:50,520 --> 00:36:54,320 Speaker 1: galaxies nearby seem to be about ten billion to thirteen 719 00:36:54,320 --> 00:36:57,319 Speaker 1: and a half billion years old, so there're no like new, 720 00:36:57,360 --> 00:37:00,520 Speaker 1: fresh galaxies in the neighborhood. But wait, how do we 721 00:37:00,560 --> 00:37:04,360 Speaker 1: know how old they are? It is pretty rude. We 722 00:37:04,440 --> 00:37:06,680 Speaker 1: have two ways to measure the age of galaxies. One 723 00:37:06,800 --> 00:37:08,840 Speaker 1: is just to look at the stuff inside of it 724 00:37:08,960 --> 00:37:12,520 Speaker 1: and say, like, can we see old populations of stars? 725 00:37:12,719 --> 00:37:15,680 Speaker 1: And this works for nearby galaxies where we can actually 726 00:37:15,760 --> 00:37:18,320 Speaker 1: resolve a few of the stars and the star clusters 727 00:37:18,360 --> 00:37:20,600 Speaker 1: and play the same trick where we try to see 728 00:37:20,640 --> 00:37:23,239 Speaker 1: some of those clusters having stars that die off, but 729 00:37:23,280 --> 00:37:26,400 Speaker 1: it's pretty hard because those galaxies are pretty far away. 730 00:37:26,920 --> 00:37:28,520 Speaker 1: Another way to do it is to look at the 731 00:37:28,640 --> 00:37:31,440 Speaker 1: like the overall light from the galaxy, and look at 732 00:37:31,480 --> 00:37:35,080 Speaker 1: the ratio of various heavy elements, because as the galaxy 733 00:37:35,160 --> 00:37:38,359 Speaker 1: gets older, the stars have burned more of the light 734 00:37:38,400 --> 00:37:41,160 Speaker 1: elements and turned them into heavier stuff. Remember that's what 735 00:37:41,280 --> 00:37:43,920 Speaker 1: happens at the heart of stars. You turn light elements 736 00:37:43,920 --> 00:37:46,759 Speaker 1: like hydrogen and helium or whatever into heavier stuff like 737 00:37:46,840 --> 00:37:49,920 Speaker 1: magnesium and eventually iron. So if you look at the 738 00:37:50,040 --> 00:37:53,440 Speaker 1: ratio of magnesium to iron, you can start to see 739 00:37:53,440 --> 00:37:56,719 Speaker 1: this change as the galaxy gets older. And so this 740 00:37:56,760 --> 00:38:00,040 Speaker 1: works mostly for younger galaxies that are far away, and 741 00:38:00,120 --> 00:38:03,240 Speaker 1: this sort of number is rapidly changing as the stars collapse. 742 00:38:03,719 --> 00:38:06,680 Speaker 1: For older galaxies, it's not as effective because it ends 743 00:38:06,719 --> 00:38:08,160 Speaker 1: up pretty stable. You end up with a lot of 744 00:38:08,200 --> 00:38:11,080 Speaker 1: stars like our sun, and the amount of iron is 745 00:38:11,080 --> 00:38:15,640 Speaker 1: not changing quickly. And we can tell these proportions from 746 00:38:15,680 --> 00:38:19,200 Speaker 1: the light right like the light these galaxies give off 747 00:38:19,400 --> 00:38:22,520 Speaker 1: sort of tell us what kind of stuff is in it. Yeah, exactly. 748 00:38:22,600 --> 00:38:24,840 Speaker 1: We can't go out and scoop up a chunk of 749 00:38:24,880 --> 00:38:27,200 Speaker 1: that galaxy and then measure it, though we'd love to 750 00:38:27,360 --> 00:38:29,160 Speaker 1: and you know, NASA comes up with an idea for 751 00:38:29,200 --> 00:38:31,560 Speaker 1: building wormholes to do it. I would definitely pay more 752 00:38:31,680 --> 00:38:34,120 Speaker 1: in taxes to make that happen. But you're right. The 753 00:38:34,160 --> 00:38:36,680 Speaker 1: only way to probe those galaxies to look at the 754 00:38:36,760 --> 00:38:39,440 Speaker 1: light that comes from them, and the light is like 755 00:38:39,480 --> 00:38:42,400 Speaker 1: a fingerprint that tells you what's in a galaxy because 756 00:38:42,680 --> 00:38:46,000 Speaker 1: different kinds of stuff glow at different frequencies. You know, 757 00:38:46,120 --> 00:38:48,719 Speaker 1: every kind of element has a different arrangement of electrons, 758 00:38:48,960 --> 00:38:51,200 Speaker 1: and it's the wiggling and jumping of those electrons that 759 00:38:51,320 --> 00:38:53,719 Speaker 1: give off the light. So there's like a fingerprint for 760 00:38:53,800 --> 00:38:56,680 Speaker 1: every element. You can tell what contributions there are from 761 00:38:56,719 --> 00:38:59,440 Speaker 1: every element just by looking at the spectrum of the light, 762 00:38:59,440 --> 00:39:01,560 Speaker 1: which frequently sees have a lot of light in which 763 00:39:01,560 --> 00:39:03,400 Speaker 1: frequencies don't have a lot of light. All right, So 764 00:39:03,440 --> 00:39:07,160 Speaker 1: that's galaxies. They are maybe about thirteen point six billion 765 00:39:07,320 --> 00:39:09,960 Speaker 1: years old, but they're kind of far away, so we 766 00:39:10,000 --> 00:39:11,680 Speaker 1: also have to kind of account for the fact that 767 00:39:11,719 --> 00:39:14,760 Speaker 1: they may not still be around today. Yeah, we're pretty 768 00:39:14,760 --> 00:39:17,319 Speaker 1: sure Andromeda is there, for example, but yeah, you never 769 00:39:17,320 --> 00:39:19,520 Speaker 1: really know because you're looking at stuff that's millions or 770 00:39:19,560 --> 00:39:21,960 Speaker 1: billions of years old. Yeah, it could have been crossing 771 00:39:22,000 --> 00:39:25,640 Speaker 1: the universe street and who knows. All right, so is 772 00:39:25,680 --> 00:39:28,600 Speaker 1: that then the oldest large scale structure in the universe 773 00:39:28,680 --> 00:39:32,080 Speaker 1: or can we see older, bigger things. There are things 774 00:39:32,200 --> 00:39:37,120 Speaker 1: probably older than galaxies that probably formed before galaxies. So 775 00:39:37,160 --> 00:39:39,440 Speaker 1: we talked about how in the early universe you had stars, 776 00:39:39,440 --> 00:39:42,200 Speaker 1: and the stars gathered together to make galaxies, but not 777 00:39:42,360 --> 00:39:44,839 Speaker 1: every club of stars was destined to make like a 778 00:39:44,880 --> 00:39:48,759 Speaker 1: full on galaxy. Sometimes they make something smaller called a 779 00:39:48,840 --> 00:39:52,359 Speaker 1: globular cluster. These things are really amazing and we're gonna 780 00:39:52,400 --> 00:39:55,359 Speaker 1: have to do a whole podcast episode just about globular 781 00:39:55,360 --> 00:39:58,239 Speaker 1: clusters and you know who give them that name. But 782 00:39:58,320 --> 00:40:02,320 Speaker 1: these are like non ga see blobs of stars usually 783 00:40:02,440 --> 00:40:05,360 Speaker 1: orbiting a galaxy. Interesting and what makes them a blob 784 00:40:05,360 --> 00:40:07,480 Speaker 1: and not a galaxy? I guess is it just like um, 785 00:40:07,760 --> 00:40:10,839 Speaker 1: it doesn't form need swirls or is there something more 786 00:40:11,000 --> 00:40:14,399 Speaker 1: fundamental about them? It's their fundamental blobbiness. Yeah, absolutely, that's 787 00:40:14,440 --> 00:40:17,080 Speaker 1: a That's a thing that visits now is that they're 788 00:40:17,120 --> 00:40:20,960 Speaker 1: smaller than galaxies. There's like a hundred thousand stars and 789 00:40:21,000 --> 00:40:24,000 Speaker 1: so there's just not big enough to form the interesting structures. 790 00:40:24,040 --> 00:40:26,000 Speaker 1: And there's also just like a naming convention. You know, 791 00:40:26,080 --> 00:40:29,239 Speaker 1: things that are smaller that are orbiting actual galaxies, You 792 00:40:29,320 --> 00:40:31,839 Speaker 1: call them a globular cluster, all right, And so those 793 00:40:31,920 --> 00:40:34,799 Speaker 1: we can tell are older than the galaxies. How can 794 00:40:34,840 --> 00:40:36,920 Speaker 1: we tell their age. We can tell their age by 795 00:40:37,000 --> 00:40:39,879 Speaker 1: looking at the stars inside them and playing the same game. 796 00:40:39,960 --> 00:40:41,799 Speaker 1: And the interesting thing is that a lot of these 797 00:40:41,800 --> 00:40:44,840 Speaker 1: clusters seem to have stars all the same age, like 798 00:40:44,880 --> 00:40:47,400 Speaker 1: they all formed at once and then just sort of 799 00:40:47,440 --> 00:40:51,000 Speaker 1: like gathered together to make this cluster. And there's one 800 00:40:51,040 --> 00:40:54,320 Speaker 1: that's pretty nearby. It's like eight thousand light years away, 801 00:40:54,640 --> 00:40:57,279 Speaker 1: and it looks like it's really really old. Well, it's 802 00:40:57,280 --> 00:41:01,160 Speaker 1: super close, I mean speaking in the skill of the universe, 803 00:41:01,280 --> 00:41:04,160 Speaker 1: eight thousand nine years away, eight thousand light years away. 804 00:41:04,280 --> 00:41:07,120 Speaker 1: It's like a satellite to our galaxy. It's orbiting the 805 00:41:07,160 --> 00:41:09,880 Speaker 1: Milky Way. It's like a little blob that's like moving 806 00:41:09,920 --> 00:41:12,399 Speaker 1: around the Milky Way. And when we look at this thing, 807 00:41:12,560 --> 00:41:15,360 Speaker 1: it looks like it's about thirteen and a half billion 808 00:41:15,440 --> 00:41:18,239 Speaker 1: years old. It's got the sexy name of n g 809 00:41:18,440 --> 00:41:23,480 Speaker 1: C sixty nineties. I love how ustromers go for sexy names. 810 00:41:24,320 --> 00:41:26,920 Speaker 1: If you if you like numbers, if you like numbers. Well, 811 00:41:26,960 --> 00:41:29,000 Speaker 1: they just see so many things, right, how can they 812 00:41:29,000 --> 00:41:31,719 Speaker 1: give them all individual names? It's like if you had 813 00:41:31,760 --> 00:41:34,680 Speaker 1: a billion children, would you come up with creative, beautiful 814 00:41:34,760 --> 00:41:36,759 Speaker 1: names for each of them where you start numbering them. 815 00:41:36,880 --> 00:41:39,279 Speaker 1: I think I would probably be dead if I don't 816 00:41:39,320 --> 00:41:44,880 Speaker 1: have any children. You would definitely be broke. All right, So, um, 817 00:41:44,920 --> 00:41:50,160 Speaker 1: it sounds like there's a galaxy globular cluster that's thirteen 818 00:41:50,200 --> 00:41:53,680 Speaker 1: point four billion years old. There's our galaxy is also 819 00:41:53,800 --> 00:41:56,560 Speaker 1: kind of that old. About that old? Um, there's a 820 00:41:56,640 --> 00:41:59,120 Speaker 1: star in our galaxy that we can tell is maybe 821 00:41:59,200 --> 00:42:02,160 Speaker 1: about that old, And there are far away galaxies we 822 00:42:02,200 --> 00:42:04,240 Speaker 1: think might be that old, or at least we're alive 823 00:42:04,320 --> 00:42:06,960 Speaker 1: back then. I guess the question then, is, Daniel, who 824 00:42:06,960 --> 00:42:08,759 Speaker 1: do we give the award to? Who? What is the 825 00:42:08,800 --> 00:42:11,200 Speaker 1: oldest thing in the universe? Whoever is willing to come 826 00:42:11,200 --> 00:42:13,200 Speaker 1: and be a guest on the podcast? That's we could 827 00:42:13,280 --> 00:42:17,799 Speaker 1: the award to have to break the tie somehow. I see, 828 00:42:17,800 --> 00:42:22,280 Speaker 1: whoever comes into tux and stays within the acceptance speech limit. 829 00:42:22,480 --> 00:42:24,840 Speaker 1: Yeah no, but you're right, we don't exactly know what 830 00:42:24,960 --> 00:42:26,600 Speaker 1: is the oldest thing in the universe. It could be 831 00:42:26,640 --> 00:42:29,319 Speaker 1: one of these stars which came together to form some 832 00:42:29,360 --> 00:42:33,120 Speaker 1: of these galaxies and globular clusters, but we're not sure. 833 00:42:33,280 --> 00:42:35,160 Speaker 1: It could be one of the black holes that's floating 834 00:42:35,200 --> 00:42:37,520 Speaker 1: around I think. I think to take away is that 835 00:42:37,560 --> 00:42:40,439 Speaker 1: there's a lot of really old stuff nearby. You don't 836 00:42:40,440 --> 00:42:43,200 Speaker 1: have to look into the depths of the universe to 837 00:42:43,239 --> 00:42:46,359 Speaker 1: see stuff that was created a long time ago, and 838 00:42:46,360 --> 00:42:48,640 Speaker 1: this stuff is still around. So there's a lot of 839 00:42:48,680 --> 00:42:52,240 Speaker 1: like awesome archaeology about the early days of the universe. 840 00:42:52,280 --> 00:42:54,520 Speaker 1: What was it like to be around a few hundred 841 00:42:54,520 --> 00:42:57,160 Speaker 1: million years after the Big Bang? Is evidence for that 842 00:42:57,320 --> 00:42:59,920 Speaker 1: right here in our backyard, because I guess we are 843 00:43:00,120 --> 00:43:02,120 Speaker 1: like still in the middle of the universe, right, Like 844 00:43:02,160 --> 00:43:04,319 Speaker 1: we're not out far away from where the action is. 845 00:43:04,520 --> 00:43:07,359 Speaker 1: You can still see things today around this that we're 846 00:43:07,400 --> 00:43:10,160 Speaker 1: around maybe around the time of the Big Bang. Yeah, 847 00:43:10,160 --> 00:43:12,600 Speaker 1: there's not really any middle of the universe, but yeah, 848 00:43:12,640 --> 00:43:14,759 Speaker 1: we're in the center of the action, that's for sure. 849 00:43:14,920 --> 00:43:17,279 Speaker 1: There's plenty of good stuff all around here to tell 850 00:43:17,360 --> 00:43:19,560 Speaker 1: us about what happened in the very early days of 851 00:43:19,560 --> 00:43:21,600 Speaker 1: the universe, and we get to watch it age. We 852 00:43:21,640 --> 00:43:23,799 Speaker 1: get to see, like when many stuff going to burn out, 853 00:43:23,960 --> 00:43:26,360 Speaker 1: what is the lifespan of a star cann go for 854 00:43:26,600 --> 00:43:29,239 Speaker 1: twenty thirty billion years. Well, my money is still on 855 00:43:29,280 --> 00:43:32,520 Speaker 1: that French old lady. I think she's going to outlive 856 00:43:32,600 --> 00:43:35,000 Speaker 1: us all and the rest of the universe. That's right, 857 00:43:35,040 --> 00:43:37,879 Speaker 1: and she'd probably still beat us all at scrabble. All right. Well, 858 00:43:37,920 --> 00:43:40,040 Speaker 1: we hope you enjoyed that and maybe think a little 859 00:43:40,080 --> 00:43:42,719 Speaker 1: bit about the age of the universe and maybe makes 860 00:43:42,760 --> 00:43:44,960 Speaker 1: you appreciate a little bit of our time in it, 861 00:43:45,239 --> 00:43:47,839 Speaker 1: because it is a pretty short clip in such an 862 00:43:47,840 --> 00:43:50,879 Speaker 1: old universe. Thanks for joining us, See you next time. 863 00:43:58,719 --> 00:44:01,520 Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain 864 00:44:01,600 --> 00:44:04,440 Speaker 1: the Universe is a production of I Heart Radio. For 865 00:44:04,600 --> 00:44:07,520 Speaker 1: More podcast for my Heart Radio, visit the I Heart 866 00:44:07,600 --> 00:44:11,200 Speaker 1: Radio Apple Apple Podcasts, or wherever you listen to your 867 00:44:11,280 --> 00:44:17,680 Speaker 1: favorite shows. Yea