1 00:00:07,560 --> 00:00:09,479 Speaker 1: Hey, Jorge, I've been meaning to ask you a really 2 00:00:09,520 --> 00:00:12,720 Speaker 1: important question. Yeah, go ahead, How old are you? How 3 00:00:12,760 --> 00:00:15,239 Speaker 1: old am I? That? Isn't that a rude question? It's 4 00:00:15,240 --> 00:00:16,919 Speaker 1: a little bit rude, but I want to mask it 5 00:00:17,000 --> 00:00:20,760 Speaker 1: by saying that I'm interested scientifically. I just want to know, like, 6 00:00:21,000 --> 00:00:23,680 Speaker 1: how did the Jorge begin? Did you start with a 7 00:00:23,720 --> 00:00:27,040 Speaker 1: big bang? Well, I'm not sure how my mom would 8 00:00:27,040 --> 00:00:30,000 Speaker 1: describe it. Am I getting better with age? Is that 9 00:00:30,080 --> 00:00:32,239 Speaker 1: kind of why you're asking? Yeah, it's Orge like a 10 00:00:32,320 --> 00:00:35,000 Speaker 1: fine wine that just gets better and better and more valuable, 11 00:00:35,159 --> 00:00:38,000 Speaker 1: or sort of like yesterday's banana. I have been working 12 00:00:38,000 --> 00:00:42,160 Speaker 1: on my earthly bouquet and under tones of cherry and oak. 13 00:00:44,320 --> 00:00:48,440 Speaker 1: I'll give you ninety points on the wine scale. Don't 14 00:00:48,440 --> 00:00:51,240 Speaker 1: you think we should focus on bigger topics? Perhaps? Yeah? 15 00:00:51,280 --> 00:00:53,200 Speaker 1: I think asking the age of stuff is a really 16 00:00:53,200 --> 00:00:55,240 Speaker 1: good way to figure out like where it came from 17 00:00:55,280 --> 00:00:57,920 Speaker 1: and why it's important and uh, and you know where 18 00:00:57,960 --> 00:01:00,200 Speaker 1: it's going to go and the whole context of every thing. 19 00:01:00,880 --> 00:01:02,840 Speaker 1: So yeah, I'm interested in how old you are, But 20 00:01:02,840 --> 00:01:05,039 Speaker 1: I'm also interested in how old the Earth is, or 21 00:01:05,120 --> 00:01:07,399 Speaker 1: how old the Solar system is, or how old the 22 00:01:07,440 --> 00:01:11,920 Speaker 1: galaxy is or even how old is like everything? You 23 00:01:11,959 --> 00:01:15,080 Speaker 1: want to be rude to everything. Yeah, I want to 24 00:01:15,080 --> 00:01:17,440 Speaker 1: ask your mom if she was around during the Big 25 00:01:17,480 --> 00:01:19,400 Speaker 1: Bang and so she can tell us all about it. 26 00:01:20,480 --> 00:01:24,959 Speaker 1: Your mom is so old she witnessed the Big Bang. Hey, look, 27 00:01:25,000 --> 00:01:42,679 Speaker 1: you're the one who brought your mom into this. Hi'm 28 00:01:42,720 --> 00:01:46,360 Speaker 1: Borning and I'm Daniel, and I'm about forty two years old. 29 00:01:46,920 --> 00:01:50,080 Speaker 1: Forty two years is the perfect age, actually, since that's 30 00:01:50,120 --> 00:01:54,320 Speaker 1: the answer to life, the universe and everything. Yeah, that's 31 00:01:54,320 --> 00:01:57,080 Speaker 1: why I brought it up, because you know, I'm the 32 00:01:57,120 --> 00:02:01,280 Speaker 1: answer to everything. They didn't notice you highly avoided staying 33 00:02:01,280 --> 00:02:03,760 Speaker 1: in your age. I thought I was doing. Did you 34 00:02:03,760 --> 00:02:05,480 Speaker 1: think that was sly? I just kind of avoid that, 35 00:02:05,520 --> 00:02:12,200 Speaker 1: didn't Yeah, and now that's double stubble sly. Oh my goodness, 36 00:02:12,480 --> 00:02:14,560 Speaker 1: can you can you go for a triple sly? Well, 37 00:02:14,800 --> 00:02:17,000 Speaker 1: let me tell you from the advanced age of forty 38 00:02:17,080 --> 00:02:19,560 Speaker 1: three that forty two is a good year. You should 39 00:02:19,600 --> 00:02:22,280 Speaker 1: enjoy yourself while you're young. You should go out there 40 00:02:22,320 --> 00:02:25,200 Speaker 1: and you know, enjoy your fitness and your your flexibility, 41 00:02:25,240 --> 00:02:30,519 Speaker 1: because when forty three comes around, everything changes, really peak life, 42 00:02:32,040 --> 00:02:34,119 Speaker 1: no jokes aside. For me, every year has been better 43 00:02:34,160 --> 00:02:36,600 Speaker 1: than the last so so far, forty three is the 44 00:02:36,639 --> 00:02:39,760 Speaker 1: best year I've ever had. Awesome? Oh what are we 45 00:02:39,800 --> 00:02:43,200 Speaker 1: talking about? This is our podcast Daniel and Jrnean explained 46 00:02:43,240 --> 00:02:46,000 Speaker 1: the universe. This is not just us chatting about random stuff. 47 00:02:46,160 --> 00:02:48,440 Speaker 1: This is our podcast where we try to explain the 48 00:02:48,440 --> 00:02:51,320 Speaker 1: whole universe to you, from front to back, from start 49 00:02:51,360 --> 00:03:00,360 Speaker 1: to finish. Today's topic how old is the universe? How 50 00:03:00,400 --> 00:03:05,000 Speaker 1: long has all of creation been around this amazing, beautiful, crazy, 51 00:03:05,160 --> 00:03:07,800 Speaker 1: chaotic mess that we find ourselves in. How long has 52 00:03:07,840 --> 00:03:10,440 Speaker 1: this party been going on? Are we at the beginning 53 00:03:10,440 --> 00:03:12,960 Speaker 1: of the party? Is a party ending? We're the best 54 00:03:13,000 --> 00:03:15,200 Speaker 1: moments of the party in the very early evening and 55 00:03:15,240 --> 00:03:19,040 Speaker 1: we've missed it already. Is the universe equivalent of forty two? 56 00:03:19,280 --> 00:03:22,799 Speaker 1: Or is it all downhill from here? That's right. Let's 57 00:03:22,800 --> 00:03:25,440 Speaker 1: hope that, like my life, every year in the universe 58 00:03:25,520 --> 00:03:27,520 Speaker 1: just gets better than the last. Right, that would be 59 00:03:27,520 --> 00:03:29,960 Speaker 1: pretty nice. Um, But I think it's a it's a 60 00:03:29,960 --> 00:03:32,840 Speaker 1: really important question. It's interesting not just from a you know, 61 00:03:32,919 --> 00:03:36,040 Speaker 1: academic physics point of view, like can we figure this out? 62 00:03:36,360 --> 00:03:38,440 Speaker 1: But I think it's one of these great questions that 63 00:03:38,560 --> 00:03:40,680 Speaker 1: touches on something. I think everybody wants to know the 64 00:03:40,680 --> 00:03:43,040 Speaker 1: answer to right, like how did it all start? And 65 00:03:43,160 --> 00:03:44,800 Speaker 1: where is it? Where is it going to go? Yeah, 66 00:03:44,880 --> 00:03:48,720 Speaker 1: it's pretty amazing to imagine not knowing how old you are. 67 00:03:48,880 --> 00:03:51,360 Speaker 1: Can you can you imagine not knowing how old you are? 68 00:03:51,680 --> 00:03:53,400 Speaker 1: That is kind of hard to imagine. I think actually 69 00:03:53,440 --> 00:03:55,480 Speaker 1: a lot of people in the world used to not 70 00:03:55,600 --> 00:03:57,960 Speaker 1: know like when they were born or how old they were, 71 00:03:58,000 --> 00:03:59,600 Speaker 1: and their parents were to tell them, oh, you were 72 00:03:59,600 --> 00:04:01,760 Speaker 1: born in the summer, it was several years ago. And 73 00:04:02,160 --> 00:04:03,360 Speaker 1: you know, I think a lot of people don't keep 74 00:04:03,400 --> 00:04:05,960 Speaker 1: track of their age. But you're right. For most modern people, 75 00:04:05,960 --> 00:04:07,760 Speaker 1: we know exactly how old we are, and that is 76 00:04:07,760 --> 00:04:10,200 Speaker 1: a big part of our identity. Yeah, I wonder if 77 00:04:10,200 --> 00:04:11,720 Speaker 1: you could figure it out, Like if you if I 78 00:04:11,760 --> 00:04:14,840 Speaker 1: went into your brain and erased that little bit of 79 00:04:14,960 --> 00:04:17,640 Speaker 1: neurons that store how old you are, if you could 80 00:04:17,680 --> 00:04:20,000 Speaker 1: piece it together just from your memories. I think if 81 00:04:20,000 --> 00:04:22,280 Speaker 1: you slice my brain open, yeah, you would find rings 82 00:04:22,320 --> 00:04:23,960 Speaker 1: and probably be able to count them and figure out 83 00:04:24,000 --> 00:04:27,800 Speaker 1: how old that was. Don't recommend doing that at home. 84 00:04:27,800 --> 00:04:32,240 Speaker 1: By the way, people said, where your old book comes from? Them? Yeah, 85 00:04:32,360 --> 00:04:33,960 Speaker 1: if I was a fine one, I think I would 86 00:04:33,960 --> 00:04:37,240 Speaker 1: be I would taste them sassy but unpretentious. Yeah, and 87 00:04:37,279 --> 00:04:40,279 Speaker 1: I'm a little nerdy, just a little bit of nerty, 88 00:04:40,800 --> 00:04:44,680 Speaker 1: just a little PhD in physics, nerdy but not not overpowering, 89 00:04:44,800 --> 00:04:48,280 Speaker 1: just enough in its undertones. Yeah, but yeah, I imagine 90 00:04:48,279 --> 00:04:50,600 Speaker 1: how disorienting it would be not to know how old 91 00:04:50,600 --> 00:04:53,359 Speaker 1: you are. Absolutely, I guess I'm trying to say. It's 92 00:04:53,400 --> 00:04:56,360 Speaker 1: that it's important to our identity to know how old 93 00:04:56,400 --> 00:04:58,880 Speaker 1: we are. Yeah, it is. And it's important identity to 94 00:04:58,920 --> 00:05:02,720 Speaker 1: know how old human civilization is, Like what is our history? 95 00:05:02,720 --> 00:05:04,920 Speaker 1: How long have people have been crawling along this planet? 96 00:05:04,920 --> 00:05:08,560 Speaker 1: How long have people been people? Right? That tells you, um, 97 00:05:08,600 --> 00:05:10,640 Speaker 1: you know of something about the context and of your 98 00:05:10,839 --> 00:05:13,720 Speaker 1: own life. And I think even more interesting is how 99 00:05:13,800 --> 00:05:17,200 Speaker 1: long our lives are compared to how long the world 100 00:05:17,279 --> 00:05:20,359 Speaker 1: has been around? You know, like we live a hundred years? 101 00:05:20,720 --> 00:05:22,680 Speaker 1: Is that long compared to the lifespan of the Earth 102 00:05:22,839 --> 00:05:25,200 Speaker 1: or in the universe? Is the universe two hundred years 103 00:05:25,240 --> 00:05:27,279 Speaker 1: old and I'm gonna live a hundred or is it 104 00:05:27,320 --> 00:05:31,640 Speaker 1: a tiny flicker in this vast, incredibly old universe? Right? 105 00:05:32,200 --> 00:05:34,480 Speaker 1: I think that helps us understand like whether we mean 106 00:05:34,520 --> 00:05:37,720 Speaker 1: anything spoiler, we don't yeah, kind of like where does 107 00:05:37,760 --> 00:05:40,560 Speaker 1: it Where do our lives fit in the history of 108 00:05:40,640 --> 00:05:44,680 Speaker 1: everything else? Yeah? And uh, even more interesting, I think 109 00:05:44,760 --> 00:05:47,640 Speaker 1: the unanswerable is not just a question of how long 110 00:05:47,800 --> 00:05:50,159 Speaker 1: are our lives compared to the history of the universe 111 00:05:50,200 --> 00:05:53,800 Speaker 1: so far, but how much history is left in the universe? Right? 112 00:05:53,960 --> 00:05:56,520 Speaker 1: Are we in the very, very beginning stages of the universe? 113 00:05:56,600 --> 00:05:58,839 Speaker 1: Is the universe of baby or is it middle age? Right? 114 00:05:58,920 --> 00:06:01,400 Speaker 1: We have a whole other podcast about that. So these 115 00:06:01,480 --> 00:06:03,720 Speaker 1: questions are important, I think. Yeah, I feel like we're 116 00:06:03,720 --> 00:06:06,760 Speaker 1: going through puberty right now, at least the United States. 117 00:06:06,760 --> 00:06:09,760 Speaker 1: Maybe your voice is already pretty low for going through puberty, Harry. 118 00:06:11,400 --> 00:06:12,839 Speaker 1: I'm not gonna ask you if you're growing hair in 119 00:06:12,839 --> 00:06:14,840 Speaker 1: any new places. I don't want to know. Is the 120 00:06:14,920 --> 00:06:17,800 Speaker 1: universe growing hair in new places? I hear that things 121 00:06:17,800 --> 00:06:20,680 Speaker 1: are pretty hairy in Mars. Black holes are growing hair. 122 00:06:20,760 --> 00:06:23,440 Speaker 1: People talk about hairy black holes these days. That's totally 123 00:06:23,480 --> 00:06:28,480 Speaker 1: a physics topic. Are black holes black haired or blonde? Well, 124 00:06:28,480 --> 00:06:30,960 Speaker 1: that's the question, is like, how many characteristics can a 125 00:06:31,000 --> 00:06:33,520 Speaker 1: black hole have? You know, because in the in the sense, 126 00:06:33,560 --> 00:06:35,760 Speaker 1: it's just a collection of matter compressed down to a 127 00:06:35,760 --> 00:06:38,479 Speaker 1: tiny scale. I know, black holes can rotate. We know 128 00:06:38,520 --> 00:06:41,000 Speaker 1: they have mass, and the question is, you know, basically, 129 00:06:41,040 --> 00:06:43,840 Speaker 1: can they have other attributes? You know? Okay, so this 130 00:06:43,880 --> 00:06:46,200 Speaker 1: is a really interesting and important question. How old is 131 00:06:46,200 --> 00:06:49,240 Speaker 1: the universe? And we were wondering how many people out 132 00:06:49,279 --> 00:06:52,520 Speaker 1: there know how old the universe is? Yeah, which is 133 00:06:52,640 --> 00:06:55,640 Speaker 1: interesting from two points of view. One is do people care? 134 00:06:55,800 --> 00:06:57,800 Speaker 1: How they spend any time thinking about it? Is it 135 00:06:57,800 --> 00:07:01,039 Speaker 1: important to people? And two, if they do care, do 136 00:07:01,160 --> 00:07:03,920 Speaker 1: they know the right answer or they operating under completely 137 00:07:03,920 --> 00:07:07,680 Speaker 1: false pretenses for how old kind of creation is? Yes, So, 138 00:07:07,720 --> 00:07:10,800 Speaker 1: as usual, Daniel went out there to his university and 139 00:07:10,880 --> 00:07:14,120 Speaker 1: asked the question how old do you think the universe is? 140 00:07:14,360 --> 00:07:18,840 Speaker 1: Here's what people had to say. I think thirteen billion years? 141 00:07:19,280 --> 00:07:22,880 Speaker 1: And do you know how we know that number? I 142 00:07:23,040 --> 00:07:27,120 Speaker 1: believe we look way out as far as we can 143 00:07:27,600 --> 00:07:30,720 Speaker 1: and detect the early gases from the universe, and then 144 00:07:30,720 --> 00:07:34,800 Speaker 1: we extrapolate based on the distance we're looking. I think 145 00:07:34,880 --> 00:07:43,840 Speaker 1: something like that fifty walk one years, fifty one years? 146 00:07:43,840 --> 00:07:47,920 Speaker 1: Oh wait, wait, world or inniversity, the universe, the university 147 00:07:48,000 --> 00:07:52,840 Speaker 1: and the universe to bill two billion? And do you 148 00:07:52,880 --> 00:07:55,080 Speaker 1: know how we know the age of the universe by 149 00:07:55,160 --> 00:07:58,240 Speaker 1: the Big Bang? Yeah, big, big theory and looking at 150 00:07:58,400 --> 00:08:04,400 Speaker 1: how far the stars are right two? Not the university, 151 00:08:04,560 --> 00:08:10,680 Speaker 1: the whole universe. Oh, I'm sorry, villain. All right, And 152 00:08:10,760 --> 00:08:12,400 Speaker 1: do you know how we know the age of the universe? 153 00:08:12,440 --> 00:08:16,880 Speaker 1: How do we measure it? Starts six billion years? Okay? 154 00:08:17,120 --> 00:08:18,880 Speaker 1: And you know how we measure the age of the universe. 155 00:08:19,120 --> 00:08:22,040 Speaker 1: I'm guessing it has to do with some type of 156 00:08:22,080 --> 00:08:27,280 Speaker 1: carbon dating materials that don't all right, cools, thanks, billion 157 00:08:27,320 --> 00:08:30,200 Speaker 1: years billions that your best guests older than twenty six 158 00:08:30,240 --> 00:08:33,800 Speaker 1: years old? And you know how we measure the age 159 00:08:33,800 --> 00:08:35,880 Speaker 1: of the universe and the idea or how would you 160 00:08:35,880 --> 00:08:37,640 Speaker 1: figure it out if you had to? I don't know, 161 00:08:37,760 --> 00:08:43,319 Speaker 1: grabbing ripples biologist, all right, thanks very much? All right, 162 00:08:43,679 --> 00:08:45,920 Speaker 1: pretty good. A lot of pretty good guesses, right, Yeah, 163 00:08:46,000 --> 00:08:48,000 Speaker 1: A lot of people guess sort of in the range 164 00:08:48,040 --> 00:08:51,520 Speaker 1: of billions of years, right, which is totally respectable. Um. 165 00:08:51,520 --> 00:08:54,079 Speaker 1: I think my favorite answers were the people who misunderstood 166 00:08:54,080 --> 00:08:56,079 Speaker 1: my question and they thought I was asking them how 167 00:08:56,120 --> 00:08:59,559 Speaker 1: old is the university and which it just turned fifty 168 00:08:59,679 --> 00:09:02,200 Speaker 1: at a big party, etcetera. But when they said fifty, 169 00:09:02,280 --> 00:09:05,080 Speaker 1: I didn't really understand that misunderstood. I thought for a 170 00:09:05,160 --> 00:09:08,640 Speaker 1: moment that they thought the universe was fifty years old, 171 00:09:08,640 --> 00:09:11,000 Speaker 1: and I thought, oh my god, I've met some really 172 00:09:11,040 --> 00:09:13,480 Speaker 1: young Earth creation is how do I respond, you know, 173 00:09:13,600 --> 00:09:16,040 Speaker 1: like to keep a straight face. I'm trying to be respectful, 174 00:09:16,120 --> 00:09:18,679 Speaker 1: you know. Um, and then I understood, oh no, they 175 00:09:18,720 --> 00:09:21,840 Speaker 1: just missed her mishearth question. Well, when you're young and 176 00:09:21,840 --> 00:09:26,439 Speaker 1: you're in college, the university is your universe in a way, right, Yeah, exactly, 177 00:09:26,640 --> 00:09:28,880 Speaker 1: that is the in their whole life. Um. I like 178 00:09:28,960 --> 00:09:30,760 Speaker 1: the guy who said, I don't know at least twenty 179 00:09:30,800 --> 00:09:33,880 Speaker 1: six years old, right, which is tells you a little 180 00:09:33,880 --> 00:09:36,440 Speaker 1: bit how self centered some college students are. But you know, 181 00:09:36,559 --> 00:09:38,920 Speaker 1: everybody gave it their shot. He's like, yeah, the universe 182 00:09:38,960 --> 00:09:41,040 Speaker 1: was here when I was born, so obviously at least 183 00:09:41,040 --> 00:09:43,760 Speaker 1: twenty six years old, that's right. And maybe that's the 184 00:09:43,760 --> 00:09:45,760 Speaker 1: only information that matters to that guy, you know, like, 185 00:09:45,840 --> 00:09:47,480 Speaker 1: who cares as long as it was around for me, 186 00:09:48,000 --> 00:09:50,680 Speaker 1: nothing else is important. Yeah, I guess his universe started 187 00:09:50,720 --> 00:09:53,720 Speaker 1: twenty six years ago. Yeah exactly. But you know he's 188 00:09:53,760 --> 00:09:57,360 Speaker 1: actually using a strategy to measure the universe which scientists use, 189 00:09:57,440 --> 00:10:00,240 Speaker 1: which is how old is stuff in the universe? The 190 00:10:00,320 --> 00:10:02,240 Speaker 1: universe has to be at least as old as that. 191 00:10:02,679 --> 00:10:05,280 Speaker 1: So while his you know, focus on himself, isn't that 192 00:10:05,480 --> 00:10:08,240 Speaker 1: helpful in determining the age of the actual universe. He's 193 00:10:08,240 --> 00:10:10,240 Speaker 1: got a good idea there about how to figure it out. 194 00:10:10,800 --> 00:10:12,920 Speaker 1: How old is the oldest thing that I know about? 195 00:10:13,240 --> 00:10:15,360 Speaker 1: That should give you give you at least like a 196 00:10:15,400 --> 00:10:18,560 Speaker 1: minimum age of the universe. Yeah, exactly, so he even 197 00:10:18,600 --> 00:10:20,840 Speaker 1: though he's a biologist, he sort of invented that strategy 198 00:10:20,880 --> 00:10:24,000 Speaker 1: on the fly. Well, I think it's important. Let's start, 199 00:10:24,040 --> 00:10:27,360 Speaker 1: first of all, talking about what it means to ask 200 00:10:27,440 --> 00:10:30,040 Speaker 1: how old the universe is? Like, what is the age? 201 00:10:30,160 --> 00:10:33,080 Speaker 1: What does the term the age of the universe mean? Yeah, 202 00:10:33,120 --> 00:10:34,920 Speaker 1: that's right, that's the kind of answer somebody would give it. 203 00:10:34,920 --> 00:10:37,600 Speaker 1: They're trying to evade a question, right, how old you Well, 204 00:10:37,640 --> 00:10:39,880 Speaker 1: what do you mean by age? I mean, do you 205 00:10:39,920 --> 00:10:44,839 Speaker 1: mean conception moment of birth? Right? Um. But there's actually 206 00:10:44,840 --> 00:10:47,280 Speaker 1: a really good analogy there, because human age is a 207 00:10:47,280 --> 00:10:49,920 Speaker 1: little fuzzy. Like if you're conceived on a certain day 208 00:10:49,960 --> 00:10:53,040 Speaker 1: and then you're born premature, you know you are older 209 00:10:53,160 --> 00:10:56,320 Speaker 1: than you otherwise would have been, right, Um. Whereas if 210 00:10:56,320 --> 00:10:59,160 Speaker 1: you stayed in your mother's womb longer, you're technically younger, 211 00:10:59,440 --> 00:11:04,559 Speaker 1: even though you know it doesn't really matter, which is 212 00:11:04,640 --> 00:11:07,920 Speaker 1: kind of arbitrary, right because technically you're body and your brain, 213 00:11:08,000 --> 00:11:12,200 Speaker 1: all your parts started earlier than your birth. Yeah, and 214 00:11:12,200 --> 00:11:15,160 Speaker 1: we're not taking a position here, and there's a fetus alive, 215 00:11:17,800 --> 00:11:19,680 Speaker 1: and maybe that's why, maybe that's why we do that. 216 00:11:19,720 --> 00:11:21,760 Speaker 1: But you know, actually I heard that in other cultures 217 00:11:21,760 --> 00:11:24,520 Speaker 1: they define age a little differently, like in someone like 218 00:11:24,559 --> 00:11:27,120 Speaker 1: in in the US, when you're born year zero, right, 219 00:11:27,120 --> 00:11:30,160 Speaker 1: and the clock starts then. But in other cultures, when 220 00:11:30,160 --> 00:11:33,600 Speaker 1: you're born, you're one, and your age increases in the 221 00:11:33,600 --> 00:11:36,280 Speaker 1: new year, and everybody goes up one year in the 222 00:11:36,320 --> 00:11:38,960 Speaker 1: new year, where the concept of age is like how 223 00:11:38,960 --> 00:11:42,320 Speaker 1: many years have you been around in not exactly how 224 00:11:42,360 --> 00:11:45,600 Speaker 1: many years since your moment of birth. Um, So the 225 00:11:45,640 --> 00:11:48,720 Speaker 1: age of the universe is sort of a similar question, right, 226 00:11:48,800 --> 00:11:51,319 Speaker 1: Like how do you define the zero with the moment 227 00:11:51,400 --> 00:11:59,160 Speaker 1: of the universe equals zero? T equals zero. Yeah, let's 228 00:11:59,320 --> 00:12:02,120 Speaker 1: let's by what it means tigal zero. So what what 229 00:12:02,280 --> 00:12:05,720 Speaker 1: I physicists mean usually when they say T equals zero, Well, 230 00:12:05,720 --> 00:12:08,920 Speaker 1: it's not terribly well defined, is the problem. What we 231 00:12:08,960 --> 00:12:10,840 Speaker 1: can do is we can say, we know when now is, 232 00:12:11,520 --> 00:12:15,440 Speaker 1: and we can walk backwards from now to what we 233 00:12:15,520 --> 00:12:17,719 Speaker 1: know to be a very hot and dense state in 234 00:12:17,800 --> 00:12:20,880 Speaker 1: the very early moments of the universe, right like a 235 00:12:20,920 --> 00:12:24,040 Speaker 1: big primordial hot plasma which is nasty and wet and 236 00:12:24,200 --> 00:12:27,000 Speaker 1: all sorts of stuff is happening right like a baby 237 00:12:27,120 --> 00:12:29,520 Speaker 1: when it's born, like a baby, exactly, a big hot, 238 00:12:29,600 --> 00:12:31,760 Speaker 1: nasty mess. It probably wasn't as loud, I don't know, 239 00:12:31,760 --> 00:12:34,640 Speaker 1: maybe it was. Actually there was very on acoustic oscillations, 240 00:12:34,679 --> 00:12:36,240 Speaker 1: so it could have been a lot of screaming going 241 00:12:36,280 --> 00:12:39,480 Speaker 1: on UM. And we understand that very well, like we 242 00:12:39,520 --> 00:12:41,880 Speaker 1: can propagate that forward to get to our universe, we 243 00:12:41,960 --> 00:12:44,720 Speaker 1: can go backwards. But the problem is that just before 244 00:12:44,800 --> 00:12:46,959 Speaker 1: that is very fuzzy for us, Like we can't see 245 00:12:47,040 --> 00:12:49,600 Speaker 1: past that. For those of you who heard our episode 246 00:12:49,600 --> 00:12:52,000 Speaker 1: about the baby universe, we can't see earlier than like 247 00:12:52,040 --> 00:12:56,400 Speaker 1: three eighty thousand years UM after the Big Bang, and 248 00:12:56,440 --> 00:12:59,160 Speaker 1: so we don't exactly know what happened then and so 249 00:12:59,400 --> 00:13:02,600 Speaker 1: exactly how to define it. It's not clear like you'd 250 00:13:02,600 --> 00:13:05,920 Speaker 1: like to say T equal zero is the big Bang? Right? Yeah? 251 00:13:06,360 --> 00:13:08,760 Speaker 1: Isn't that what they usually mean that the universe started 252 00:13:08,800 --> 00:13:11,680 Speaker 1: with the Big Bang or we don't know, right, except 253 00:13:11,679 --> 00:13:13,600 Speaker 1: that we don't really have a great definition of what 254 00:13:13,679 --> 00:13:15,760 Speaker 1: the Big Bang is, right, Like, we don't know what 255 00:13:15,800 --> 00:13:20,000 Speaker 1: was the Big Bang? Was it a singularity that then exploded? Um? 256 00:13:20,240 --> 00:13:23,840 Speaker 1: Was it you know, some weird quantum blob? Was it inflotons? 257 00:13:23,920 --> 00:13:26,520 Speaker 1: Like that? Whole process is still very mysterious to us. 258 00:13:26,800 --> 00:13:28,800 Speaker 1: So we don't know exactly what happened and exactly how 259 00:13:28,840 --> 00:13:31,720 Speaker 1: long it took, so we can do you just blew 260 00:13:31,720 --> 00:13:35,040 Speaker 1: my mind a little bit. Yeah, scientists think Tiko zero 261 00:13:35,200 --> 00:13:37,640 Speaker 1: is the moment possibly of the Big Band, but you're 262 00:13:37,640 --> 00:13:41,400 Speaker 1: saying it's possibly, Like we don't really know what happened 263 00:13:41,440 --> 00:13:44,440 Speaker 1: around the time of Tiko zero. Yeah, and the I mean, 264 00:13:44,440 --> 00:13:46,120 Speaker 1: the whole definition of the Big Bang is still a 265 00:13:46,200 --> 00:13:48,400 Speaker 1: kind of bit fuzzy, Like some people think the Big 266 00:13:48,400 --> 00:13:50,760 Speaker 1: Bang is sort of still happening. Like what was the 267 00:13:50,800 --> 00:13:54,360 Speaker 1: Big Bang? It was this inflation of a dense amount 268 00:13:54,360 --> 00:13:56,960 Speaker 1: of matter into a hot promodial gas that was on 269 00:13:57,000 --> 00:14:01,000 Speaker 1: a macroscopic scale, right, really fast inflation and took less 270 00:14:01,000 --> 00:14:03,760 Speaker 1: than ten to the minus thirty seconds, right, and that 271 00:14:03,960 --> 00:14:06,600 Speaker 1: ever since then, things have been expanding, But things are 272 00:14:06,640 --> 00:14:09,440 Speaker 1: still expanding and they're still inflating, like we have dark energy, 273 00:14:09,440 --> 00:14:13,320 Speaker 1: which is just like a modern day analogy of of inflation. 274 00:14:13,400 --> 00:14:14,840 Speaker 1: So from some point of view, you could say, like, 275 00:14:14,880 --> 00:14:17,599 Speaker 1: the Big Bang is still banging. So then when do 276 00:14:17,640 --> 00:14:19,560 Speaker 1: you put to equal zero from the beginning of the 277 00:14:19,560 --> 00:14:22,040 Speaker 1: Big Bang? Like, we don't really understand very well the 278 00:14:22,080 --> 00:14:23,920 Speaker 1: physics of what happened in the early days, so it's 279 00:14:23,920 --> 00:14:26,520 Speaker 1: hard to define what T equal zero is. So you mean, 280 00:14:26,600 --> 00:14:29,600 Speaker 1: we can look back in our history, and there you 281 00:14:29,680 --> 00:14:32,320 Speaker 1: get to a point where you can look beyond and 282 00:14:32,360 --> 00:14:35,040 Speaker 1: you just assume that there's some sort of event beyond that. 283 00:14:35,120 --> 00:14:37,800 Speaker 1: But we can't see that's right. You don't have records 284 00:14:37,800 --> 00:14:40,800 Speaker 1: of your of yourself beyond pictures of you when you 285 00:14:40,800 --> 00:14:42,360 Speaker 1: were one year old, Like you don't you have no 286 00:14:42,440 --> 00:14:44,760 Speaker 1: idea what you look like before you were one years 287 00:14:44,760 --> 00:14:46,520 Speaker 1: old exactly. And so what you can do is you 288 00:14:46,560 --> 00:14:48,760 Speaker 1: can extrapolate. You can say, like, well, I know how 289 00:14:48,760 --> 00:14:50,320 Speaker 1: it happened when I went from one to two and 290 00:14:50,320 --> 00:14:52,240 Speaker 1: two to three and three to four, and I understand 291 00:14:52,240 --> 00:14:54,560 Speaker 1: the biology of and so I can extrapolate backwards from 292 00:14:54,600 --> 00:14:56,920 Speaker 1: one and think about what zero must have been like 293 00:14:57,000 --> 00:14:59,600 Speaker 1: and when zero was right, how long it took to 294 00:14:59,600 --> 00:15:01,880 Speaker 1: get to one, which is really the question when you 295 00:15:01,960 --> 00:15:05,680 Speaker 1: when you were conceived probably yeah, exactly. But if you 296 00:15:05,720 --> 00:15:09,360 Speaker 1: suspect that the physics happening down there between zero and one, 297 00:15:09,480 --> 00:15:11,440 Speaker 1: you know, just after the moments of the Big Bang, 298 00:15:11,880 --> 00:15:16,000 Speaker 1: we're different, we're interesting, um or maybe not typical of 299 00:15:16,040 --> 00:15:17,480 Speaker 1: what happened the rest of your life, then there's a 300 00:15:17,520 --> 00:15:20,160 Speaker 1: lot of uncertainty how to do that extrapolation. You can't 301 00:15:20,200 --> 00:15:23,640 Speaker 1: just blindly extrapolate, like what if the physics before I 302 00:15:23,680 --> 00:15:26,400 Speaker 1: was one years old were totally different, which means I 303 00:15:26,400 --> 00:15:28,360 Speaker 1: could be older than one year old when I think 304 00:15:28,360 --> 00:15:30,760 Speaker 1: I'm one year old. Yeah exactly. And it's not that 305 00:15:30,800 --> 00:15:33,000 Speaker 1: we think the laws of physics were different, but you 306 00:15:33,040 --> 00:15:36,000 Speaker 1: don't just different stuff was happening. Stuff we haven't seen, stuff, 307 00:15:36,000 --> 00:15:39,080 Speaker 1: we haven't had a chance to understand, um stuff. So 308 00:15:39,520 --> 00:15:42,720 Speaker 1: you know, we're extrapolating down, down, down, down down. But 309 00:15:42,760 --> 00:15:44,720 Speaker 1: we get to a region where we have don't really 310 00:15:44,720 --> 00:15:47,560 Speaker 1: have a lot of data to extrapolate into, so we're 311 00:15:47,600 --> 00:15:51,280 Speaker 1: skeptical of that extrapolation. But this is a very technical 312 00:15:51,280 --> 00:15:54,600 Speaker 1: discussion of like exactly when ti equal zero is. The 313 00:15:54,640 --> 00:15:57,440 Speaker 1: good news is doesn't really matter. What do you mean, 314 00:15:57,480 --> 00:16:00,280 Speaker 1: it doesn't matter. We just talk about how important was. 315 00:16:01,280 --> 00:16:04,240 Speaker 1: It doesn't really matter exactly when you define to equal zero, 316 00:16:04,320 --> 00:16:07,880 Speaker 1: because this uncertainty is a small number compared to the 317 00:16:07,880 --> 00:16:10,280 Speaker 1: age of the universe. Like we can extrapolate all the 318 00:16:10,360 --> 00:16:13,400 Speaker 1: way from now back to you know, less than a 319 00:16:13,440 --> 00:16:17,800 Speaker 1: million years after the Big Bang whatever that was, right, um, 320 00:16:17,840 --> 00:16:19,560 Speaker 1: And so there's an uncertainty there of like you know, 321 00:16:19,600 --> 00:16:21,760 Speaker 1: a million years, a couple of million years whatever for 322 00:16:21,840 --> 00:16:24,920 Speaker 1: what happened before the part we can extrapolate beyond. But 323 00:16:25,160 --> 00:16:27,040 Speaker 1: that's a small fraction we think of the age of 324 00:16:27,080 --> 00:16:28,800 Speaker 1: the universe. So if you want to say how old 325 00:16:28,840 --> 00:16:31,320 Speaker 1: is the universe, you can sort of sweep that question 326 00:16:31,400 --> 00:16:33,800 Speaker 1: under the rug. You can say, well, you know, how 327 00:16:33,840 --> 00:16:36,080 Speaker 1: old is it? How far back can we see? And 328 00:16:36,120 --> 00:16:39,880 Speaker 1: that's really to the age of the universe. So if 329 00:16:39,880 --> 00:16:42,480 Speaker 1: I said, Daniel, I hear you're forty three years old 330 00:16:42,760 --> 00:16:46,080 Speaker 1: plus or minus a million years, you would just sweep 331 00:16:46,120 --> 00:16:48,680 Speaker 1: that under the rug. I would say, no, that's an 332 00:16:48,680 --> 00:16:53,440 Speaker 1: accurate statement or a correct statement. Oh that's right. Technically 333 00:16:53,600 --> 00:16:57,680 Speaker 1: you are yeah plus or minus a million yeah, more 334 00:16:57,680 --> 00:17:00,840 Speaker 1: plus than minus but um, yeah, exactly. But I think 335 00:17:00,840 --> 00:17:02,680 Speaker 1: a better analogy would be like, you know, I'm forty 336 00:17:02,680 --> 00:17:05,960 Speaker 1: three plus or minus a day, you know, or a second. 337 00:17:06,200 --> 00:17:08,760 Speaker 1: Right there, These are details on the scale of the 338 00:17:08,800 --> 00:17:11,199 Speaker 1: times we're talking about. But you know, we want our 339 00:17:11,240 --> 00:17:13,879 Speaker 1: listeners to really understand the nitty gritty, and so the 340 00:17:13,920 --> 00:17:16,200 Speaker 1: exact definition the age of the universe is a little 341 00:17:16,200 --> 00:17:19,320 Speaker 1: bit fuzzy because those first few fractions of a second 342 00:17:19,440 --> 00:17:23,400 Speaker 1: especially are not well understood. Okay, so when we say 343 00:17:23,440 --> 00:17:26,800 Speaker 1: the age of the universe, we really mean how old 344 00:17:26,920 --> 00:17:31,800 Speaker 1: the universe is since some mysterious thing happened called the 345 00:17:31,840 --> 00:17:36,080 Speaker 1: Big Bang. That's right, exactly, and even deeper, right, we 346 00:17:36,119 --> 00:17:38,600 Speaker 1: don't know what happened before that, So it's just an 347 00:17:38,680 --> 00:17:40,720 Speaker 1: arbitrary thing to call that t equal zero. Right. It 348 00:17:40,720 --> 00:17:42,760 Speaker 1: could have been that before the Big Bang there was 349 00:17:42,760 --> 00:17:45,000 Speaker 1: another universe which had like a big bang of its 350 00:17:45,000 --> 00:17:48,320 Speaker 1: own and a big crunch. It's not really a different universe. 351 00:17:48,320 --> 00:17:50,720 Speaker 1: It's just like part another cycle. And this could have 352 00:17:50,720 --> 00:17:53,440 Speaker 1: been happening forever. So when you talk about the age 353 00:17:53,440 --> 00:17:55,320 Speaker 1: of the universe, you really can only talk about the 354 00:17:55,359 --> 00:17:59,160 Speaker 1: age since this early state that we understand. What happened 355 00:17:59,160 --> 00:18:01,480 Speaker 1: before that is a little question mark, Like the universe 356 00:18:01,520 --> 00:18:03,920 Speaker 1: could have just started before that it could have gone 357 00:18:03,960 --> 00:18:07,320 Speaker 1: on forever before that. Okay, let's let's get into how 358 00:18:07,320 --> 00:18:09,600 Speaker 1: we know all this stuff, but first let's take a 359 00:18:09,640 --> 00:18:25,800 Speaker 1: quick break. Okay, Daniels, settle this for us. How old 360 00:18:25,960 --> 00:18:31,360 Speaker 1: do physicists think the universe is? Years old? I mean, 361 00:18:31,359 --> 00:18:35,000 Speaker 1: that's how long? So what else is important? Um? You know, 362 00:18:35,240 --> 00:18:39,040 Speaker 1: the most accurate age of the universe currently is thirteen 363 00:18:39,080 --> 00:18:42,440 Speaker 1: point eight billion years. That's how long we think the 364 00:18:42,520 --> 00:18:46,200 Speaker 1: universe has been expanding since that hot, dense, nasty mess 365 00:18:46,240 --> 00:18:48,520 Speaker 1: at the very beginning. Okay, And just to put them 366 00:18:48,560 --> 00:18:53,080 Speaker 1: into perspective, the Solar system is four point five billion 367 00:18:53,160 --> 00:18:55,439 Speaker 1: years old, that's right. So solar system has only been 368 00:18:55,480 --> 00:18:58,080 Speaker 1: around for the last third of this party. There was 369 00:18:58,200 --> 00:19:02,560 Speaker 1: ten billion years almost when we didn't even have our star, right, Wow, 370 00:19:02,720 --> 00:19:05,240 Speaker 1: So the two thirds of the universe there was nothing 371 00:19:05,240 --> 00:19:07,040 Speaker 1: where we are. Oh, there might have been stuff, right, 372 00:19:07,040 --> 00:19:09,239 Speaker 1: there might have been other stars, there might have been 373 00:19:09,240 --> 00:19:12,680 Speaker 1: globular clusters or gas or whatever. But our star took 374 00:19:12,760 --> 00:19:17,600 Speaker 1: ten billion years to even form. Wow. Okay. And by that, 375 00:19:17,960 --> 00:19:20,800 Speaker 1: by the same account, the Earth itself is about four 376 00:19:20,960 --> 00:19:24,040 Speaker 1: billion years old, that's right. Yeah, it took less than 377 00:19:24,080 --> 00:19:26,640 Speaker 1: a billion years for life to start on Earth. Yeah, 378 00:19:26,680 --> 00:19:29,440 Speaker 1: and then to put that in scale, my families university, 379 00:19:29,480 --> 00:19:32,960 Speaker 1: you see, Irvine is fifty years old, right, so now 380 00:19:33,000 --> 00:19:37,080 Speaker 1: the party has started. Well, the United States is only 381 00:19:37,119 --> 00:19:39,720 Speaker 1: about It always blows my mind a little bit. In 382 00:19:39,800 --> 00:19:42,080 Speaker 1: the United States, it's only like two d and fifty 383 00:19:42,160 --> 00:19:44,639 Speaker 1: years old, lessan two fifty years old. I know. My 384 00:19:44,680 --> 00:19:47,280 Speaker 1: brother keeps reminding me of that because his university is 385 00:19:47,320 --> 00:19:49,760 Speaker 1: like three times as old as our country. Right. He's 386 00:19:49,760 --> 00:19:53,119 Speaker 1: at Oxford, so they have traditions, they have like probably 387 00:19:53,119 --> 00:19:55,159 Speaker 1: have silver ware over there that's older than our country. 388 00:19:55,320 --> 00:19:57,840 Speaker 1: So he's he's a younger brother and he's like trying 389 00:19:57,840 --> 00:20:02,159 Speaker 1: to find something to get to tab over. You aren't 390 00:20:02,160 --> 00:20:04,480 Speaker 1: always aren't younger brothers always doing that? No, he is 391 00:20:04,520 --> 00:20:07,200 Speaker 1: an academic rock star at Oxford, and so he gets 392 00:20:07,200 --> 00:20:09,360 Speaker 1: to um, he gets to look down and the rest 393 00:20:09,359 --> 00:20:12,359 Speaker 1: of us at fairly new universities. Okay, so thirteen point 394 00:20:12,440 --> 00:20:16,159 Speaker 1: eight billion years old? That's how old the universe we 395 00:20:16,200 --> 00:20:18,520 Speaker 1: think it is? And how do how do we know that? 396 00:20:18,560 --> 00:20:20,639 Speaker 1: How do we know there is there a birth certificate? 397 00:20:20,840 --> 00:20:24,800 Speaker 1: Is there like DNA evidence? Well, I've been asking your mom, 398 00:20:24,960 --> 00:20:27,520 Speaker 1: but she claims had not been around then. So we 399 00:20:27,560 --> 00:20:30,160 Speaker 1: have to figure it out for ourselves. Um, there's basically 400 00:20:30,280 --> 00:20:33,160 Speaker 1: two ways that we we know the age of the universe, 401 00:20:33,200 --> 00:20:36,119 Speaker 1: And this is really classic science strategy. Is like, find 402 00:20:36,160 --> 00:20:40,280 Speaker 1: two completely separate, independent ways of asking the same question, 403 00:20:40,960 --> 00:20:44,040 Speaker 1: and then if they agree, then awesome. You think probably 404 00:20:44,119 --> 00:20:45,960 Speaker 1: you haven't figured out and if they don't agree, then 405 00:20:46,000 --> 00:20:49,960 Speaker 1: you know something's wrong. Like two independent experts, yeah, or 406 00:20:50,040 --> 00:20:52,360 Speaker 1: two suspects more like like if you're a detective, you're 407 00:20:52,359 --> 00:20:54,560 Speaker 1: trying to figure out, um, you know, who did something. 408 00:20:54,600 --> 00:20:56,840 Speaker 1: You find two suspects, you separate them, You ask them 409 00:20:56,880 --> 00:21:00,000 Speaker 1: questions separately. If they tell you all the same details, 410 00:21:00,000 --> 00:21:01,840 Speaker 1: they're probably telling the truth, right. If they give you 411 00:21:01,880 --> 00:21:04,800 Speaker 1: totally different stories, then you know they're lying. So science 412 00:21:04,840 --> 00:21:06,639 Speaker 1: is sort of like that. Okay, so what's the first 413 00:21:06,680 --> 00:21:08,919 Speaker 1: way that we know how old the universe is? The 414 00:21:08,960 --> 00:21:12,160 Speaker 1: first way is just looking for old stuff. Like if 415 00:21:12,200 --> 00:21:15,440 Speaker 1: you find something in the universe that's fifty billion years old, 416 00:21:15,440 --> 00:21:17,760 Speaker 1: then you know the universe is at least fifty billion 417 00:21:17,800 --> 00:21:19,960 Speaker 1: years old. Right, It's not very complicated. So you just 418 00:21:20,040 --> 00:21:22,119 Speaker 1: look around and you try to figure out how old 419 00:21:22,280 --> 00:21:24,440 Speaker 1: is the stuff around us, And that's it's a sort 420 00:21:24,440 --> 00:21:26,720 Speaker 1: of a lower limit on the age of the universe. 421 00:21:26,840 --> 00:21:29,280 Speaker 1: So if you find a rock that's sixty billion years old, 422 00:21:29,359 --> 00:21:31,560 Speaker 1: then you know the universe must be at least sixty 423 00:21:31,600 --> 00:21:34,040 Speaker 1: billion years old, that's right. Yeah. Or if you find 424 00:21:34,040 --> 00:21:36,919 Speaker 1: an unpaid bill from fourteen billion years ago, right, then 425 00:21:36,960 --> 00:21:42,520 Speaker 1: you know you know your universe is about to end, 426 00:21:43,119 --> 00:21:46,680 Speaker 1: that's right. You know exactly they're coming for you. Um, yeah, 427 00:21:46,720 --> 00:21:48,679 Speaker 1: and um. But that's a tricky thing to do, right, 428 00:21:48,760 --> 00:21:50,640 Speaker 1: how do you know the age of stuff? Right? We've 429 00:21:50,720 --> 00:21:52,359 Speaker 1: changed one question how do you know the age of 430 00:21:52,359 --> 00:21:55,080 Speaker 1: the universe into another question, which is how do you 431 00:21:55,119 --> 00:21:58,639 Speaker 1: know the age of stuff we see around us? Right? Yeah, Well, 432 00:21:58,680 --> 00:22:01,040 Speaker 1: what's the oldest stuff that we know about? Then? Yeah, 433 00:22:01,080 --> 00:22:04,879 Speaker 1: the oldest stuff that we know about is stars basically, 434 00:22:05,320 --> 00:22:07,520 Speaker 1: I mean, there's this a caveat there with the cosmic 435 00:22:07,560 --> 00:22:10,480 Speaker 1: microwave background, which we we know, um is a little 436 00:22:10,480 --> 00:22:13,320 Speaker 1: bit older, but that's more difficult to age. But direct 437 00:22:13,400 --> 00:22:15,040 Speaker 1: stuff that we can see that we can ask the 438 00:22:15,160 --> 00:22:18,680 Speaker 1: question how old is it our stars? And we look 439 00:22:18,760 --> 00:22:22,880 Speaker 1: around and we look for really really old stars and 440 00:22:22,640 --> 00:22:24,359 Speaker 1: and and this is a tricky thing to do. But 441 00:22:24,400 --> 00:22:26,480 Speaker 1: what you can do is you can look for blobs 442 00:22:26,480 --> 00:22:30,680 Speaker 1: of stars they're called globular clusters. These are collections of stars. 443 00:22:30,680 --> 00:22:32,760 Speaker 1: There's sort of like many galaxies. I mean, they have 444 00:22:32,760 --> 00:22:35,800 Speaker 1: a whole different name from them because of the sized distinction. 445 00:22:35,840 --> 00:22:39,960 Speaker 1: But they're called globular clusters. He didn't like mini galaxies galaxinos. 446 00:22:40,119 --> 00:22:45,040 Speaker 1: I thought that would have been good glaxin exactly. That 447 00:22:45,080 --> 00:22:49,360 Speaker 1: sounds like a nice pasta. I'll have the galaxins with anchovies, please. Um. Yes. 448 00:22:49,440 --> 00:22:52,080 Speaker 1: So you look at these globular clusters and you ask 449 00:22:52,160 --> 00:22:53,960 Speaker 1: how old are they? How old are the stars in 450 00:22:54,000 --> 00:22:57,480 Speaker 1: these globular clusters. And it's hard to know how old 451 00:22:57,480 --> 00:22:59,680 Speaker 1: an individual star is, but you can look at a 452 00:22:59,760 --> 00:23:01,560 Speaker 1: group of them and you can figure out how old 453 00:23:01,600 --> 00:23:04,479 Speaker 1: that group is, really, yeah, based on which ones are 454 00:23:04,480 --> 00:23:07,119 Speaker 1: still there and which ones are not there anymore. And 455 00:23:07,160 --> 00:23:10,640 Speaker 1: the reason is that stars have different life spans. Right, 456 00:23:10,680 --> 00:23:13,560 Speaker 1: So you form a bunch of stars, and um, they 457 00:23:13,640 --> 00:23:15,800 Speaker 1: form out of gas and dust. They coalesce with gravity, 458 00:23:15,840 --> 00:23:17,720 Speaker 1: and you get some really big ones and you get 459 00:23:17,720 --> 00:23:20,760 Speaker 1: some really little ones. Now, the big ones burn really 460 00:23:20,840 --> 00:23:23,200 Speaker 1: fast and they don't last very long, and the little 461 00:23:23,240 --> 00:23:25,720 Speaker 1: ones they burn a long time. They're like saving their fuel. 462 00:23:26,160 --> 00:23:29,360 Speaker 1: Remember stars burned by compressing hydrogen, right, and then they 463 00:23:29,359 --> 00:23:31,879 Speaker 1: glow and they burn it's its fusion and you can 464 00:23:32,040 --> 00:23:34,159 Speaker 1: listen to our podcast episode about that if you're curious 465 00:23:34,160 --> 00:23:37,000 Speaker 1: about that. Um But the big ones burn out pretty quickly. 466 00:23:37,359 --> 00:23:39,320 Speaker 1: So if you're looking at a population of stars really 467 00:23:39,359 --> 00:23:42,199 Speaker 1: really far away and you notice that they still have 468 00:23:42,280 --> 00:23:44,040 Speaker 1: a bunch of big ones in them, you know it's 469 00:23:44,080 --> 00:23:46,560 Speaker 1: pretty young because those ones would have burned out already 470 00:23:46,560 --> 00:23:49,240 Speaker 1: if it was old, like the cluster itself is young. 471 00:23:49,560 --> 00:23:52,560 Speaker 1: Like the cluster itself is young, exactly. And if you 472 00:23:52,600 --> 00:23:55,280 Speaker 1: find a club a group of stars the globular cluster 473 00:23:55,640 --> 00:23:58,240 Speaker 1: that only has little stars and it left, then you 474 00:23:58,280 --> 00:24:00,720 Speaker 1: know it's pretty old, and because has been time for 475 00:24:00,760 --> 00:24:03,760 Speaker 1: all the bigger stars to burn out. So what's the 476 00:24:03,800 --> 00:24:06,120 Speaker 1: oldest star that we know about? Or how old are 477 00:24:06,160 --> 00:24:08,080 Speaker 1: the oldest stars that we know about? Well, this is 478 00:24:08,119 --> 00:24:11,240 Speaker 1: really fascinating. It's been controversial because this is a hard 479 00:24:11,280 --> 00:24:13,360 Speaker 1: thing to do. You have to know how far these 480 00:24:13,400 --> 00:24:15,880 Speaker 1: things are away. You have to measure their light. There's 481 00:24:15,880 --> 00:24:19,040 Speaker 1: a connection between the color of the star and its size, 482 00:24:19,440 --> 00:24:22,080 Speaker 1: so it's a lot of intermediate steps. Right, you see 483 00:24:22,119 --> 00:24:24,280 Speaker 1: the color that tells you the size that you can 484 00:24:24,320 --> 00:24:26,520 Speaker 1: make a distribution of the sizes. There's a lot of 485 00:24:26,560 --> 00:24:28,880 Speaker 1: steps that go along, and there's a lot of uncertainty 486 00:24:28,960 --> 00:24:32,439 Speaker 1: and um. Things happen very quickly in the beginning of 487 00:24:32,480 --> 00:24:34,720 Speaker 1: a life cycle of a globular cluster, like the big 488 00:24:34,800 --> 00:24:37,520 Speaker 1: bright stars burn out fast. Near the end, things happen 489 00:24:37,560 --> 00:24:40,960 Speaker 1: more slowly, which means for really old stuff, the uncertainties 490 00:24:40,960 --> 00:24:43,400 Speaker 1: are pretty large. Like it's hard to tell the difference 491 00:24:43,880 --> 00:24:47,280 Speaker 1: between a ten billion year old globular cluster and an 492 00:24:47,280 --> 00:24:50,000 Speaker 1: eleven billion year old, but between one and two billion 493 00:24:50,119 --> 00:24:53,160 Speaker 1: is easier. So people have been looking at these things 494 00:24:53,240 --> 00:24:55,560 Speaker 1: for a while, and the oldest ones we found are 495 00:24:55,600 --> 00:24:59,600 Speaker 1: something like thirteen billion years old. That's a very recent estimate. 496 00:24:59,800 --> 00:25:02,560 Speaker 1: A till like twenty years ago, people thought they had 497 00:25:02,600 --> 00:25:05,520 Speaker 1: found globular clusters that were like twenty billion years old 498 00:25:05,600 --> 00:25:09,240 Speaker 1: or even thirty billion years old. Did you say thirty thirty? Yeah, 499 00:25:09,400 --> 00:25:12,360 Speaker 1: they think so, maybe the universe is thirty billion years old. 500 00:25:12,560 --> 00:25:14,200 Speaker 1: Well that's what they thought. For a while. They had 501 00:25:14,200 --> 00:25:16,320 Speaker 1: this one measurement from the stars that was saying like 502 00:25:16,359 --> 00:25:19,359 Speaker 1: twenty or thirty billion years old, and they thought, well, 503 00:25:19,440 --> 00:25:21,679 Speaker 1: let's compare that to the measure to other ways we 504 00:25:21,680 --> 00:25:24,080 Speaker 1: can measure the age of the universe. Now the most 505 00:25:24,119 --> 00:25:26,800 Speaker 1: current one that they in the end, they found some 506 00:25:26,800 --> 00:25:29,040 Speaker 1: some mistakes and they updated it, and they weren't like 507 00:25:29,080 --> 00:25:31,760 Speaker 1: you know, um, somebody goofed by adding one plus one 508 00:25:31,840 --> 00:25:34,040 Speaker 1: making three. You know, we just got a better understanding 509 00:25:34,080 --> 00:25:36,119 Speaker 1: of how stars evolved and how they burn and how 510 00:25:36,160 --> 00:25:38,879 Speaker 1: to do these calibrations. And now the more recent updates 511 00:25:38,880 --> 00:25:40,920 Speaker 1: are like thirteen billion years old. But for a while 512 00:25:40,960 --> 00:25:45,199 Speaker 1: it seemed like those globular clusters were suggesting the universe 513 00:25:45,280 --> 00:25:47,880 Speaker 1: is older than twenty billion years. So so there are 514 00:25:47,920 --> 00:25:50,920 Speaker 1: things out there in the universe that we're there when 515 00:25:50,920 --> 00:25:54,480 Speaker 1: the universe started that are still around today. Well not quite. 516 00:25:54,480 --> 00:25:57,600 Speaker 1: When the universe started, right, We're looking at stars, and 517 00:25:57,760 --> 00:25:59,600 Speaker 1: you know the universe started, there was the Big Bang. 518 00:25:59,640 --> 00:26:02,080 Speaker 1: There's a mess of plasma things spread out and cooled off, 519 00:26:02,119 --> 00:26:04,800 Speaker 1: and then stars formed from that gas and dust. Those 520 00:26:04,800 --> 00:26:07,639 Speaker 1: it called the first generation stars. None of those stars 521 00:26:07,640 --> 00:26:09,719 Speaker 1: are still around. We can't see those stars. Nobody's ever 522 00:26:09,720 --> 00:26:11,800 Speaker 1: seen those We're looking for them. It's people want to 523 00:26:11,840 --> 00:26:14,720 Speaker 1: understand it, but nobody's seen those stars. The o G 524 00:26:14,960 --> 00:26:19,000 Speaker 1: stars exactly back when stars were cool, man, back when 525 00:26:19,000 --> 00:26:22,320 Speaker 1: they were hot. Um, yeah, and then those didn't last 526 00:26:22,400 --> 00:26:24,760 Speaker 1: very long. And then they know they burned, they cool, 527 00:26:24,840 --> 00:26:27,360 Speaker 1: they exploded supernovas, and you have this, they gather their 528 00:26:27,400 --> 00:26:30,760 Speaker 1: back together. You have the second generation of stars. Remember 529 00:26:30,760 --> 00:26:33,639 Speaker 1: stars are in this cycle, right, They burn, they then 530 00:26:33,640 --> 00:26:36,280 Speaker 1: they explode and their fuel gets spread out into the universe. 531 00:26:36,560 --> 00:26:39,399 Speaker 1: Then the gathered back together and make another cycle. And 532 00:26:39,440 --> 00:26:41,520 Speaker 1: so the second or third generation of the sort of 533 00:26:41,560 --> 00:26:44,359 Speaker 1: the oldest stars that we can see so far. And 534 00:26:44,359 --> 00:26:46,680 Speaker 1: that's why it's a lower limit, right, we see something 535 00:26:46,720 --> 00:26:49,560 Speaker 1: super old. We don't know if the universe is older, 536 00:26:49,600 --> 00:26:51,840 Speaker 1: how much older than that the universe is. We just 537 00:26:51,880 --> 00:26:55,240 Speaker 1: know it's at least that old. It's like finding a 538 00:26:55,280 --> 00:26:59,000 Speaker 1: relic from an ancient civilization. You know that the civilization 539 00:26:59,080 --> 00:27:00,520 Speaker 1: is at least at all, but it could have been 540 00:27:00,520 --> 00:27:03,000 Speaker 1: around for much longer. Just because you haven't found something older, 541 00:27:03,000 --> 00:27:05,439 Speaker 1: it doesn't mean that it wasn't older. That's right, exactly. 542 00:27:05,480 --> 00:27:07,960 Speaker 1: It's such a lower limit. And currently that lower limit 543 00:27:08,000 --> 00:27:10,639 Speaker 1: is about thirteen billion years old. That's the oldest thing 544 00:27:10,680 --> 00:27:13,400 Speaker 1: that we found. So we're seeing things from the very 545 00:27:13,480 --> 00:27:16,359 Speaker 1: very early universe, not exactly from the beginning, right, but 546 00:27:16,440 --> 00:27:19,800 Speaker 1: from very very early on, which is pretty awesome. Right, 547 00:27:19,840 --> 00:27:21,960 Speaker 1: that's like the ancient history of the universe. It's I 548 00:27:21,960 --> 00:27:24,679 Speaker 1: think that's super cool. Yeah. Imagine like coming up to 549 00:27:24,760 --> 00:27:27,960 Speaker 1: these clusters and you're staring at something that's been around 550 00:27:28,000 --> 00:27:31,240 Speaker 1: for thirteen billion years old. Yeah, that would be pretty amazing. Yeah. Well, 551 00:27:31,280 --> 00:27:34,959 Speaker 1: I mean I'm already just flabbergasted looking down at the Earth. Right, 552 00:27:35,000 --> 00:27:37,600 Speaker 1: the Earth has been around for five billion years. It's 553 00:27:37,680 --> 00:27:40,679 Speaker 1: such an ancient rock. It's seen so much history. I 554 00:27:40,720 --> 00:27:42,360 Speaker 1: think about that when I you know, we just walk 555 00:27:42,400 --> 00:27:45,240 Speaker 1: across the planet, I wonder like, who else is stepped here. 556 00:27:45,480 --> 00:27:47,040 Speaker 1: That's one of the things that makes me love those 557 00:27:47,119 --> 00:27:50,440 Speaker 1: um footprints, Right, you can see like footprints of dinosaurs 558 00:27:50,840 --> 00:27:52,919 Speaker 1: from hundreds of millions of years ago, like they were 559 00:27:52,920 --> 00:27:55,920 Speaker 1: just like walking along boop um. You know, so much 560 00:27:55,920 --> 00:27:57,480 Speaker 1: has happened on this planet. We don't we're not even 561 00:27:57,520 --> 00:27:59,840 Speaker 1: aware of. There's so much history that's just been lost 562 00:28:00,600 --> 00:28:07,359 Speaker 1: that will never know. Okay, So that's one way we 563 00:28:07,400 --> 00:28:09,800 Speaker 1: know how old d universe is. What's the other way 564 00:28:09,840 --> 00:28:11,840 Speaker 1: we know? The other way is by looking at the 565 00:28:11,840 --> 00:28:14,840 Speaker 1: expansion of the universe. We know that the universe is 566 00:28:14,880 --> 00:28:17,440 Speaker 1: spreading out. Things are moving away from us, and they're 567 00:28:17,440 --> 00:28:20,600 Speaker 1: moving away from us faster and faster every year, and 568 00:28:20,680 --> 00:28:23,000 Speaker 1: we can measure that. We look out in the universe 569 00:28:23,000 --> 00:28:25,159 Speaker 1: and we see how fast things are moving away from us. 570 00:28:25,200 --> 00:28:27,040 Speaker 1: We can measure that by looking at how the light 571 00:28:27,080 --> 00:28:29,960 Speaker 1: from them is stretched. Things that are moving away from 572 00:28:30,000 --> 00:28:32,960 Speaker 1: you have their light waves stretched out longer, they turn 573 00:28:33,000 --> 00:28:35,439 Speaker 1: more red. Things that are moving towards you have their 574 00:28:35,520 --> 00:28:38,480 Speaker 1: light waves squeezed, they turn more blue. This is the 575 00:28:38,520 --> 00:28:40,880 Speaker 1: Doppler effect. It's the same effect that makes like a 576 00:28:40,920 --> 00:28:44,680 Speaker 1: police siren sound different as it's approaching you and leaving you. Right, 577 00:28:45,240 --> 00:28:47,000 Speaker 1: So we can use that to measure how fast things 578 00:28:47,000 --> 00:28:49,239 Speaker 1: are moving away from us. And if you remember our 579 00:28:49,280 --> 00:28:52,560 Speaker 1: podcast episode about dark energy and the expansion of the universe, 580 00:28:53,040 --> 00:28:56,520 Speaker 1: we have these really cool standard candles are called supernova 581 00:28:56,760 --> 00:28:59,920 Speaker 1: type one a supernova, and we we know how bright 582 00:29:00,000 --> 00:29:01,360 Speaker 1: they should be, and we can look at them, we 583 00:29:01,360 --> 00:29:03,680 Speaker 1: can measure their velocity, we know how far away they are, 584 00:29:04,000 --> 00:29:06,920 Speaker 1: so use that to measure how fast the universe is expanding. 585 00:29:07,320 --> 00:29:10,840 Speaker 1: That's important because remember we talked about the definition of 586 00:29:10,880 --> 00:29:13,160 Speaker 1: the start was really what we're doing when we're measuring 587 00:29:13,160 --> 00:29:15,200 Speaker 1: the age of the universes, we're saying how long has 588 00:29:15,240 --> 00:29:18,920 Speaker 1: the universe been expanding since that hot date. And if 589 00:29:18,960 --> 00:29:23,440 Speaker 1: you know, um, the expansion rate, then you can extrapolate backwards. 590 00:29:23,760 --> 00:29:26,960 Speaker 1: So we we we hit the rewind button from what 591 00:29:27,280 --> 00:29:29,520 Speaker 1: how fast we think the universe is expanding, and that 592 00:29:30,320 --> 00:29:33,320 Speaker 1: makes the university you watch it in reverse, makes the 593 00:29:33,400 --> 00:29:35,640 Speaker 1: universe go down, down, down, down down into a very 594 00:29:35,680 --> 00:29:39,600 Speaker 1: small blob. Yeah, exactly. The Ebreody starts talking finding because 595 00:29:39,600 --> 00:29:43,200 Speaker 1: of backwards. Yeah. And the critical thing is that you 596 00:29:43,200 --> 00:29:44,720 Speaker 1: have to measure the rate, right We have to know 597 00:29:44,760 --> 00:29:47,960 Speaker 1: the expansion rate to know how fast to rewind, and 598 00:29:48,400 --> 00:29:49,960 Speaker 1: we have to know the expansion right now, and the 599 00:29:49,960 --> 00:29:52,640 Speaker 1: expansion made a billion years ago and ten billion years ago. 600 00:29:52,960 --> 00:29:55,280 Speaker 1: And we can do all that because remember, the further 601 00:29:55,320 --> 00:29:57,560 Speaker 1: we look out into space, the further we're looking back 602 00:29:57,640 --> 00:30:00,560 Speaker 1: into history, and we can see the expansion and right now, 603 00:30:00,640 --> 00:30:02,160 Speaker 1: we can see it a while ago, we can see 604 00:30:02,160 --> 00:30:04,600 Speaker 1: it a long time ago. Like the history of the 605 00:30:04,680 --> 00:30:07,400 Speaker 1: universe is written out there in the stars, like you 606 00:30:07,400 --> 00:30:10,920 Speaker 1: can tell, yeah, exactly, how fascinating we're expanding throughout the 607 00:30:10,960 --> 00:30:13,640 Speaker 1: history of the universe. Yeah, and our history is out 608 00:30:13,680 --> 00:30:16,760 Speaker 1: there also. You know, light left the Earth um when 609 00:30:16,800 --> 00:30:19,200 Speaker 1: you were ten, and you you know, did something embarrassing 610 00:30:19,200 --> 00:30:22,000 Speaker 1: at your cousin's birthday party. Light from that event left 611 00:30:22,000 --> 00:30:23,960 Speaker 1: the earth and is still out there, and somebody could 612 00:30:24,000 --> 00:30:26,000 Speaker 1: capture it and see that, right, even though it happened 613 00:30:27,200 --> 00:30:30,200 Speaker 1: years ago, So all that information is still out there. Yeah, 614 00:30:30,480 --> 00:30:34,560 Speaker 1: so watch out, So watch out. Light come back and 615 00:30:34,560 --> 00:30:37,040 Speaker 1: and expose your ten year old antics. That's right. Well, 616 00:30:37,040 --> 00:30:39,040 Speaker 1: when the aliens come, they'll have seen it, right, so 617 00:30:39,080 --> 00:30:42,479 Speaker 1: they'll know who's been naughty and who's been nice. Santa 618 00:30:42,600 --> 00:30:46,200 Speaker 1: is an alien? Oh? Did I just reveal that on 619 00:30:46,240 --> 00:30:50,280 Speaker 1: the air. Oops? Yes, Santa is an alien. Um. I 620 00:30:50,280 --> 00:30:52,160 Speaker 1: mean Santa can do a whole bunch of stuff that 621 00:30:52,160 --> 00:30:53,880 Speaker 1: nobody else can do, right. I think having him be 622 00:30:53,920 --> 00:30:56,720 Speaker 1: an alien with supertech is really the only reasonable expert 623 00:30:56,760 --> 00:30:59,960 Speaker 1: would explain it. Santa myth boom, We just saw that 624 00:31:00,080 --> 00:31:03,400 Speaker 1: mystery right there. Well, this is a perfect point to 625 00:31:03,440 --> 00:31:18,480 Speaker 1: take a break. So if you know the expansion rate 626 00:31:18,520 --> 00:31:20,640 Speaker 1: the universe, you can rewind back and we actually measure 627 00:31:20,640 --> 00:31:23,440 Speaker 1: the expansion RDE two different ways. One is just by 628 00:31:23,520 --> 00:31:27,000 Speaker 1: looking at how things are moving right right these stars. 629 00:31:27,560 --> 00:31:30,640 Speaker 1: The other is by looking at the cosmic microwave background. 630 00:31:31,000 --> 00:31:33,600 Speaker 1: This is the light from the very early moments of 631 00:31:33,640 --> 00:31:37,320 Speaker 1: the universe. That also tells us how old the universe is. Yeah, 632 00:31:37,400 --> 00:31:40,160 Speaker 1: it contains an incredible amount of information about what was 633 00:31:40,200 --> 00:31:42,640 Speaker 1: going on in the early universe, how much dark matter 634 00:31:42,720 --> 00:31:45,400 Speaker 1: there was, how much normal matter there was, how dense 635 00:31:45,440 --> 00:31:49,000 Speaker 1: it was, all of that stuff and all that information 636 00:31:49,040 --> 00:31:51,360 Speaker 1: in the end can tell you about the expansion rate 637 00:31:51,360 --> 00:31:54,320 Speaker 1: of the universe. Um. But you can extract the expansion 638 00:31:54,400 --> 00:31:57,000 Speaker 1: rate directly from that. That's actually the most precise way 639 00:31:57,040 --> 00:31:58,920 Speaker 1: to do it UM. And then once you know the 640 00:31:58,920 --> 00:32:01,400 Speaker 1: expansion rate, you can rewind the universe to figure out 641 00:32:01,400 --> 00:32:03,720 Speaker 1: how old it is. And that's the measurement that tells 642 00:32:03,800 --> 00:32:06,680 Speaker 1: us it's thirteen point eight billion years, and the uncertainty 643 00:32:06,680 --> 00:32:09,760 Speaker 1: on that it's about twenty one million years. So it's 644 00:32:09,760 --> 00:32:12,600 Speaker 1: pretty accurate plus or minus twenty one million years, depends 645 00:32:12,600 --> 00:32:15,400 Speaker 1: on your scale. But it's kind of interesting that, you know, 646 00:32:15,440 --> 00:32:17,920 Speaker 1: scientists hit the rewind button, right, we look at into 647 00:32:17,960 --> 00:32:20,280 Speaker 1: the stars, we hit we pressed the rewind button. We 648 00:32:20,280 --> 00:32:23,719 Speaker 1: see it all compressed, and then we sort of stop 649 00:32:23,880 --> 00:32:26,760 Speaker 1: once it gets really small, right, because we a we 650 00:32:26,960 --> 00:32:30,600 Speaker 1: can't rewind further, but also kind of conceptually right, like 651 00:32:30,640 --> 00:32:33,640 Speaker 1: we we can't imagine there being anything before that or 652 00:32:33,680 --> 00:32:37,240 Speaker 1: we can't imagine anything surviving being that small. Yeah, and 653 00:32:37,280 --> 00:32:39,440 Speaker 1: we have to ask questions like what does it even mean? 654 00:32:39,560 --> 00:32:42,800 Speaker 1: You know, Um, space and time started at the Big Bang? 655 00:32:42,880 --> 00:32:45,800 Speaker 1: So can you count before the Big Bang? You get 656 00:32:45,800 --> 00:32:50,600 Speaker 1: into really really difficult philosophical waters. Absolutely, um. And you know, 657 00:32:50,640 --> 00:32:53,040 Speaker 1: it's only recently that we've known this, Like this seems 658 00:32:53,040 --> 00:32:54,800 Speaker 1: to like going to be an important piece of information. 659 00:32:54,840 --> 00:32:56,800 Speaker 1: It tells me something about who I am and how 660 00:32:56,840 --> 00:32:59,440 Speaker 1: to live my life and how meaningless it is. But 661 00:32:59,520 --> 00:33:01,760 Speaker 1: it's sort of a new piece of information. You know, 662 00:33:01,800 --> 00:33:05,120 Speaker 1: Like a hundred years ago, people thought the universe was 663 00:33:05,200 --> 00:33:07,040 Speaker 1: steady state, right, that there was just a bunch of 664 00:33:07,040 --> 00:33:10,120 Speaker 1: stars out there and they've basically always been there, and 665 00:33:10,160 --> 00:33:12,720 Speaker 1: the universe wasn't expanding or contracting. It didn't have a 666 00:33:13,160 --> 00:33:15,520 Speaker 1: interesting history or a moment of birth. It's just been 667 00:33:15,560 --> 00:33:18,560 Speaker 1: around forever. This was a hundred years ago, right, only 668 00:33:19,040 --> 00:33:21,520 Speaker 1: only a hundred years ago, so from most of human history. 669 00:33:21,680 --> 00:33:23,240 Speaker 1: First of all, for most of the ministry, we didn't 670 00:33:23,280 --> 00:33:26,600 Speaker 1: understand anything about anything, right, so we were basically completely 671 00:33:26,920 --> 00:33:30,520 Speaker 1: all ignory missus um. You just exalted most of humanity. 672 00:33:30,560 --> 00:33:34,920 Speaker 1: But go ahead, I mean, in the best possible. Way 673 00:33:35,960 --> 00:33:39,080 Speaker 1: Um but yeah, um, And only about a hundred years 674 00:33:39,120 --> 00:33:40,719 Speaker 1: ago do we even figure out that there might have 675 00:33:40,760 --> 00:33:43,280 Speaker 1: been a beginning, that there was this expansion, which suggests, 676 00:33:43,720 --> 00:33:45,280 Speaker 1: you know, that that that there was that if you 677 00:33:45,360 --> 00:33:48,360 Speaker 1: rewound it, you got back to a very early, hot, 678 00:33:48,440 --> 00:33:51,360 Speaker 1: nasty state. A hundred years ago, we thought the universe 679 00:33:51,520 --> 00:33:56,000 Speaker 1: had been around forever, right, So yeah, like forever infinity right? Yeah? 680 00:33:56,000 --> 00:33:58,360 Speaker 1: So what was that like to learn that the universe, uh, 681 00:33:58,800 --> 00:34:00,960 Speaker 1: to go from age of the uni versus infinity to 682 00:34:01,040 --> 00:34:03,360 Speaker 1: agees you know, in the in the billions of years. 683 00:34:03,480 --> 00:34:05,240 Speaker 1: And it wasn't until the fifties that we had any 684 00:34:05,280 --> 00:34:07,960 Speaker 1: sort of accurate estimate because these things are hard to measure. 685 00:34:07,960 --> 00:34:10,239 Speaker 1: It's taken decades to get the technology and the math 686 00:34:10,320 --> 00:34:12,680 Speaker 1: and the physics models. So it's in the fifties that 687 00:34:12,760 --> 00:34:16,000 Speaker 1: really had the first accurate estimate of the universe's age 688 00:34:16,000 --> 00:34:23,080 Speaker 1: about fourteen billion years wow. Okay, so the universe is 689 00:34:23,160 --> 00:34:27,640 Speaker 1: thirteen point eight billion years old plus or minus twenty 690 00:34:27,680 --> 00:34:30,560 Speaker 1: one million years old. And so what does that mean? 691 00:34:30,600 --> 00:34:32,439 Speaker 1: What does that What does that tell us about how 692 00:34:32,440 --> 00:34:35,359 Speaker 1: the universe came to be or where it's all going? 693 00:34:35,640 --> 00:34:37,920 Speaker 1: It tells us something about how far we are along. 694 00:34:37,960 --> 00:34:40,160 Speaker 1: You know, we know that we've we've been around for 695 00:34:40,280 --> 00:34:43,160 Speaker 1: long enough for galaxies to form, right, for galaxies to 696 00:34:43,200 --> 00:34:46,239 Speaker 1: spin for a while, for stars to form and explode 697 00:34:46,239 --> 00:34:48,759 Speaker 1: and coalesce again in form and explode. Right, we're not 698 00:34:48,840 --> 00:34:51,719 Speaker 1: in the very first few moments of the universe. But 699 00:34:51,760 --> 00:34:53,560 Speaker 1: we don't really know much more than that. Yeah, and 700 00:34:53,560 --> 00:34:56,400 Speaker 1: more important, we don't even know how old the universe 701 00:34:56,920 --> 00:34:58,799 Speaker 1: is going to be, right, We don't know how old 702 00:34:58,800 --> 00:35:01,319 Speaker 1: the universe is going to be around. So we could 703 00:35:01,400 --> 00:35:04,120 Speaker 1: be in a very early part of the universe, or 704 00:35:04,160 --> 00:35:05,920 Speaker 1: we could be in a really late part of the universe. 705 00:35:05,960 --> 00:35:08,920 Speaker 1: We don't really know. No, we have no idea exactly. Um, 706 00:35:08,920 --> 00:35:11,719 Speaker 1: it could be that in a trillion years. There are 707 00:35:11,800 --> 00:35:14,000 Speaker 1: life forms that are studying the age of the universe 708 00:35:14,000 --> 00:35:16,600 Speaker 1: and they think about this little this first little bit, 709 00:35:16,640 --> 00:35:19,200 Speaker 1: the first fifteen billion years as like the big bang. 710 00:35:19,400 --> 00:35:21,960 Speaker 1: Right to them, this could have just been like the 711 00:35:22,000 --> 00:35:25,719 Speaker 1: engine just getting started, you know, platform from stars and galaxies. 712 00:35:26,080 --> 00:35:28,160 Speaker 1: We don't know, and we don't know if this part 713 00:35:28,160 --> 00:35:30,480 Speaker 1: of the age of the universe is typical, right, Like, 714 00:35:30,520 --> 00:35:33,440 Speaker 1: it could be that things go along and everything turns 715 00:35:33,440 --> 00:35:35,520 Speaker 1: to black holes and they have like only black holes 716 00:35:35,520 --> 00:35:39,560 Speaker 1: for a trillion years. Right, Um, so we really don't know. 717 00:35:39,760 --> 00:35:42,920 Speaker 1: When is the puberty of the universe? Right things changing? 718 00:35:43,080 --> 00:35:45,080 Speaker 1: Is it already grown up? We don't know. So maybe 719 00:35:45,120 --> 00:35:47,560 Speaker 1: the real question we should be asking, the one that's 720 00:35:47,840 --> 00:35:52,200 Speaker 1: less rude, is how young the universe is? Young? Is 721 00:35:52,280 --> 00:35:55,560 Speaker 1: the universe exactly? Hey, universe, how do you feel? You're 722 00:35:55,560 --> 00:35:58,880 Speaker 1: feeling pretty good? You got some joint pain. You've been 723 00:35:58,920 --> 00:36:01,239 Speaker 1: planning for your retirement. Yeah, you know, like if you 724 00:36:01,280 --> 00:36:03,479 Speaker 1: knew you were going to live to a thousand years old, 725 00:36:03,760 --> 00:36:05,799 Speaker 1: you would say things like, oh, I'm only forty two 726 00:36:05,880 --> 00:36:09,120 Speaker 1: years young instead of forty two years old. That's right. 727 00:36:09,640 --> 00:36:11,320 Speaker 1: If I knew I was going to live to a thousand, 728 00:36:11,360 --> 00:36:13,360 Speaker 1: I would have started saving for retirement a lot, a 729 00:36:13,360 --> 00:36:17,160 Speaker 1: lot earlier. You want to be retired for nine thousand, 730 00:36:17,200 --> 00:36:20,960 Speaker 1: nine hundred and sixty years. No, honestly, I'm never going 731 00:36:21,000 --> 00:36:22,600 Speaker 1: to retire. I mean, I have tenure. Why should ever 732 00:36:22,640 --> 00:36:24,799 Speaker 1: retirement to sit in my office for the next year 733 00:36:24,880 --> 00:36:32,200 Speaker 1: and you're already retired mentally mentally retired? You know you 734 00:36:32,280 --> 00:36:34,360 Speaker 1: do your best work and you have tenure. That's exactly 735 00:36:34,400 --> 00:36:37,239 Speaker 1: the point. You're free to think and expand and go 736 00:36:37,320 --> 00:36:40,800 Speaker 1: to crazy places in your career, like recording a podcast 737 00:36:40,840 --> 00:36:43,840 Speaker 1: with a cartoonist, right, yeah, sure, yeah, And the universe 738 00:36:43,960 --> 00:36:48,800 Speaker 1: is fifty years old. Universe's fifty years young, alright, everyone. 739 00:36:48,960 --> 00:36:51,239 Speaker 1: So that's the answer to the question how old is 740 00:36:51,280 --> 00:36:53,879 Speaker 1: the universe? And how do we know? Or how young 741 00:36:53,960 --> 00:36:57,320 Speaker 1: is the universe? How young isn't the universe? Oh my god, Universe, 742 00:36:57,440 --> 00:37:04,520 Speaker 1: you look good. You're looking sparkly. That's right, keep burning bright, Universe. 743 00:37:04,719 --> 00:37:07,160 Speaker 1: You're happy to be around. See you next time. Thanks 744 00:37:07,160 --> 00:37:17,279 Speaker 1: for tuning in. If you still have a question after 745 00:37:17,320 --> 00:37:20,479 Speaker 1: listening to all these explanations, please drop us a line. 746 00:37:20,520 --> 00:37:22,640 Speaker 1: We'd love to hear from you. You can find us 747 00:37:22,640 --> 00:37:26,480 Speaker 1: at Facebook, Twitter, and Instagram at Daniel and Jorge that's 748 00:37:26,480 --> 00:37:29,880 Speaker 1: one word, or email us at Feedback at Daniel and 749 00:37:30,000 --> 00:37:39,960 Speaker 1: Jorge dot com.