Pratique du Shadowing: Why Do We Exist? With Hakeem Oluseyi - Apprendre l'anglais à l'oral avec la vidéo
Création de la leçon...
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just like the cell is the fundamental building block of the
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body the galaxy is the fundamental building block of the universe what
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if i shrink myself down so small
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that the size of a cell to me is the same
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ratio to the size of my galaxy what would i do i would do what hubble did he looked around
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and say oh there are these things called galaxies they come
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in different types i look around there's different cells blood muscle bone right
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but then you can zoom out
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and you see we discovered the large -scale structure right
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but after doing all that would you have any idea if if you're in a whale, if you're in a horse, if you're in a tree.
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You can't get the context of your existence from the inside of the damn animal.
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Can the unborn child know what its mother looks like?
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Ooh.
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Space fact.
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Dark matter is 85 % of all the gravity we measure in the universe, and we don't know what's causing it.
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It doesn't interact with our light.
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It doesn't even interact with itself,
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which means it cannot coalesce to form solid objects like stars or planets or people.
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This is StarTalk.
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Neil deGrasse Tyson, your personal astrophysicist.
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Chuck Nice, right next to me.
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What's up, Neil?
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All right, man.
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How are you, buddy?
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Doing good?
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Doing great.
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We've got a Cosmic Queries today.
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Yes, we do, inquiring minds want to know.
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Indeed, and in fact, it's on cosmology as a topic.
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It is the expertise of our guest.
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Third time on StarTalk?
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Yeah!
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I think so.
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That's right.
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Hakeem Ulusheye.
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Thank you so much.
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And it is the fourth time.
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Fourth time!
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Oh, that's right, because this...
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Yeah, no, wait, fourth time?
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Memoir, Cosmic Queries, both remote, and then finally...
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Oh, you know, remote, that's right.
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Yeah, it kind of messed me up.
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Well, we got an astrophysicist cosmologist, which is a subdivision of all astrophysicists who thinks about the origin,
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evolution, and fate of the universe.
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Ooh.
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Right.
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Plus, he's been practicing my open for this show.
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And I don't know if I should be happy about it or kick his ass later.
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Let me hear it.
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Go.
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Let's see.
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This is StarTalk.
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You know, that's pretty good.
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Not bad.
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Gotta tell you.
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You know?
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Right now, with three black guys up here, I don't know who's who.
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Wait a minute, wait a minute.
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I wanna get back to this kick -your -ass comedy.
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That's hilarious.
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So you're a host of the podcast Particles of Thought.
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I love that title.
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And it's a NOVA podcast.
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It's a NOVA podcast.
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PBS NOVA, GBH, out of Boston.
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Very good.
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Very nice. And CEO.
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How many people get to say they CEO?
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Because you CEO, you the man.
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That's right.
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CEO of the Astronomical Society of the Pacific.
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Very nice.
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And I'm going to ask you about that in a minute.
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And you've also associated with NASA's IMAP satellite.
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Yes.
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Remind me what IMAP stands for.
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Interstellar Mapping and Acceleration Probe.
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Nice.
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Who's accelerating?
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The sun's magnetic fields both at the surface of the sun and interactions with the sun, solar wind, and particles trapped in the heliosphere.
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Right?
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And those generate neutral atoms that come back into the solar system and they get measured by IMAP.
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Wow.
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Yeah, okay, all right.
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And may I ask, why?
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And if you're worried about the sun, that doesn't sound very cosmological.
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It doesn't.
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How do you stitch that together?
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Because I started out doing instrumentation and calculations, computational, and understanding plasmas really well.
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So it's kind of like I have this toolbox that I can travel from field to field with, right?
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So I've done propulsion.
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Because plasma is everywhere in the freaking universe absolutely oh my
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god yeah tell people we're not talking about blood plasma no we're kind of like I forgot about
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that yeah yeah it's a whole other kind of plasma
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so this is when you take a gas heat it even more you break more bonds right
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and you break the solid to liquid bond liquid to gas now once you're a gas you're just molecules
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or atoms you start breaking those apart
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so once you break apart electrons from atoms you now have a plasma yeah it's an electron soup
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And so this gas will respond to magnetic fields.
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You can do really cool things with it, including feed a fusion reactor for the future of energy.
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Very nice.
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That's where anybody's going to go.
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Yeah.
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And that'd be the only way you would be able to hold the energy, is in a magnetic field bottle, right?
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Not necessarily.
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No?
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Really?
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What the hell else?
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You can also put it in a little pellet, enclose it in a metal, and blast it, generating x -rays that create fusion.
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Oh, but that's not a...
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I'm sorry.
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I was thinking fusion.
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That's not a plasma.
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You're starting with a little seed, right?
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Right.
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But yeah, so if you're going to confine a plasma, you're going to do that with magnetic fields.
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Okay.
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Yeah, a magnetic bottle.
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So you were right.
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You were on the cast.
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Totally on the cast.
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Yeah, you totally shook my confidence there.
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Last you were here, you've been busy, and you wrote a book.
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I did.
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A book with the audacious title, the bodacious title, the out of this world title, why do we exist?
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Wow.
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The nine realms of universe that make you possible.
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Mm -hmm.
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This sounds very Asgardian.
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So wait, the realms.
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That's right, the realms.
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Yeah, that's right.
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So you say they make you exist.
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Does that mean, because you're speaking to the reader, does that mean you have a different point of origin?
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Because otherwise that word really should be a we.
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Just saying.
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I think it is a we.
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Why do we exist, the nine realms of the universe that make you possible?
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That's right.
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That's right.
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That's kind of like, you know, when you're talking to your spouse and you say, let me tell you something, your son, Okay.
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Gotcha.
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Okay.
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Okay.
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Tear a new one right there.
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That's what that...
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Okay.
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That sums it up, because I've said those words many times.
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And sometimes you might hear, you mean our son?
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Yeah.
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So what is a realm?
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So in this case, what I do is I listen to what the universe told me, and I report on it.
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Essentially, what I realized as a physicist is that when you study the universe, we typically do it in this disjointed way right
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but there is a cohesive story
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but what the average person doesn't understand is how the rules
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that that our intuition gives us just doesn't scale
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and the universe as it scales the rules change fundamentally
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so you have to really start looking at the universe completely differently
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so here we're in the middle realm i call the middle realm bigger than an atom
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or molecule smaller than a galactic arm right it's middle earth
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like yeah exactly what about second breakfast are you going to the shower what happened
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so anyway the cosmological realm right
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so now the dynamics of space -time dominate in the middle realm the dom you know
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and what dominates is based on the flow of energy through
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that realm so what you see the trend is is energy is constantly leaving matter going from
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and it's really a story of quantum fields going from the
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matter to fermionic quantum fields into the electromagnetic quantum fields
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so every day there's more photons than there were the day
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before there's less energy in matter right ultimately leading to this
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heat death right the long time in the future now we go
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if you study the cosmological realm you realize something ain't right
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that leads you to the dark
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so these are energy realms in a sense well no they're they're realms of emergence as well right
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so when you go to for example the temporal realm the story of how time unfolds
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but listen in other realms there are still unfoldings in the middle realm I discuss how stars
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and planets come into existence in the realm of life we talked about a biogenesis and how
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that leads ultimately you know through this energy ladder from chemo
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synthesis to you know anoxic photosynthesis to oxygenic photosynthesis to oxygenic respiration right this energy ladder
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that leads to a brain like yours okay yeah absolutely Yeah, exactly.
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And then you have the realms beyond horizons, beyond our cosmic event horizons, within the black hole event horizons.
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Okay.
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That's unknowable.
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Yeah.
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And then you have the multiverse.
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So now when you look at the cosmic microwave background radiations, super horizon signature, that seems to indicate that inflation occurred.
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Is that just the edge of the observable universe?
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What's the super horizon?
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I don't know that if you look at the tt spectrum of the cosmic microwave background radiation
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which you get from looking at the sizes of these yeah
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you'll see to the beyond the biggest lump there's a dip right
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and that's known as the super horizon fluctuation okay so
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when you look at the inflationary epic of the universe okay
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right you have a situation now where our boundary the cosmic event horizon is moving out outwards right right
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but at early times during inflation right it could have been moving inwards
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and so areas that were separated
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that were within your you know outside your horizon now would have been inside your horizon
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so you can get these bigger fluctuates you know I screwed up
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when I when I described the Andromeda paradox here slightly even though the world now knows it Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Thank you.
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Very differently motivated when you read it, you'll be like so you're saying the information
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that was unavailable to him You took and use that as the basis for your equation.
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Not exactly.
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Okay, here's what I did I started my equation.
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He started his his equations is written in many ways in terms of outcomes life is formed a
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Civilization forms technologies forms mine is around the drivers for life, right?
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so if you look at the just right stars what defines a just right star it has to have
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that right exactly now what defines a just right planet that's that's valid what you're saying is very valid okay
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so it's the only shahey equation inspired by the drake equation
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and the seager equation i'll have to add right
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because sarah seager from m .i .t also came out with an equation i know
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but a big uh planet person yeah okay yeah all right and now astrobiology yeah yes yes
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very cool well that's that's excellent yeah man
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so they're going to come away with a cognitive map of reality
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that will allow them to okay so so
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so i think i i spoke wrong about it what you're saying is we'll read the book
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and then come away reflecting absolutely absolutely yeah read the reviews
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that's what you know it's like wow this is something different to think about
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and then when the physicist here's the thing you're gonna like
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so you're different from the average person because you've heard it all
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and you're probably at a point now where you've probably heard it all
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so you have a new perspective see that's what i love about you man
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when i first met you you didn't meet me but
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when i first met you i was like man like the thing you did
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that went super viral where you're talking about the stars
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when somebody asked you yeah they asked me what's the most mind -blowing fact exactly
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yeah as an astronomy dude it's still going viral i'd heard
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that i had heard this you know we all hear
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that young right yeah but i never heard it like
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that i never heard nobody made me feel it right you know I'm saying
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and so I think this particular provocation is gonna hit hits in a different way for physicists like
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that got it because you've seen it all
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and now somebody comes at it from this other angle
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and you're like oh I see what you're saying
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so you're taking information
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that we already thought about in bits you put it together in a new way
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and there's new material yeah there's a lot of new original things
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that bit you think it was called the most astonishing fact I was asked by Time magazine sitting in this chair Really?
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It had a long interview.
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He said, what's the most astonishing fact?
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And then I had to think about it for a moment.
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Then I delivered an answer, which then other people plucked and then put B -roll visuals behind it.
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And that's what really took off.
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Not just me sitting here delivering the answer.
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Okay.
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Yeah.
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Okay.
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So that's a noble goal.
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It is.
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It is.
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It is.
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All right.
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One of the central ideas in Hakeem's new book is that humanity can not only understand the forces that made us possible, but use science and imagination to decide where we go next.
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That makes President Trump's proposed U .S.
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Space Academy an interesting extension of that idea.
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His August 28th order created a commission to develop plans for a NASA -led federal academy focused on training future space leaders.
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But the coverage shows just how differently that future can be interpreted.
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Over 250 outlets covered the story with varied opinions and Ground News lets us step back and see those differences clearly.
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Left -leaning coverage tends to focus on questions about cost, structure and whether the Academy is necessary,
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while right -leaning coverage more often frames it as a bold investment in American space leadership and competition.
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Same story, different framing.
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That's why we've partnered with Ground News for years.
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Ground News brings reporting from more than 50 ,000 sources into one place and shows you the bias, credibility and ownership behind the coverage.
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Their Blindspot feed also services stories getting disproportionate attention from one side of the political spectrum,
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giving you a better sense of which stories may be missing from your usual media diet.
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If that's the world you want to live in, you can get the same unlimited vantage plan we use for 40 % off at ground .news .startalk,
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or by scanning the QR code on the screen.
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So there's an acronym associated with you called SWAG.
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SWAG.
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Of course there is.
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SWAG.
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As an acronym, how do you get that?
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How do you get those letters?
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That's a scientific wild -ass guess.
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Wild -ass guess.
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I like it.
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What a scientist.
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That's black for hypothesis.
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No!
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Informed hypothesis.
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Informed hypothesis. So tell me.
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Give me an example.
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What's that?
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Well, everything I've been telling you.
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I tell you right in the book.
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The whole book is my swag.
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I got you.
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This is a scientific, wild -ass guess, but it's highly informed, right?
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I've been thinking about this.
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Okay.
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But normally, like, you write a paper, get it published, peer reviewed, and then a book comes after that.
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That's right.
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Yeah, yeah.
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Well, this is not that kind of work.
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This is not for them.
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So, you know, I've been in a world of the pros forever, right?
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And, you know, this is for everybody else.
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Okay.
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Yeah, but for the pros, too.
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So, you know, this is not a quantitative study only one tiny part of
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the book has a couple of equations in it right
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so there's no data it's an exploration of ideas it's deeper than
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that man you know it's an exploration of deep ideas deep ideas right
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but it's also a man it's just so dope so but
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if we unpack this idea it's anyone could come up with a wild ass guess that's right
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but not all of them would be scientifically tracked Exactly.
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So help me understand that distinction.
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Well, the distinction is if I were going to submit a paper, I would have a hypothesis.
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Okay.
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And typically you're going to study some very narrow question, right?
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This is very broad.
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And what I'm doing is something that a professional in my position doesn't really normally do.
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So when a physicist interviewed me, he said, Hakeem, what I don't understand about you, bro, is how are you so courageous?
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How are you so brave?
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You just throw out your ideas and you don't care what people think.
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And that's what I've done in this case.
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I've, you know, we talk about crazy ideas privately, right?
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But, hey, I'm putting it out there for the world.
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Once I snitched on myself in my memoir, I might as well tell you my crazy thoughts about the universe, too.
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But they're well grounded.
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Okay.
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Okay, so these are well -formed, scientifically -based imaginings.
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Isn't everything an imagining?
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In many respects, yes.
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But no, it's not that.
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I'm a serious empiricist, so I have to stay within the boundary of what we have observed to be true.
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I have to stay within the boundary.
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Scientifically informed.
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That's the scientifically informed part.
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So if you're imagining what can be within the boundaries of scientific soundness, that's what I'm talking about.
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Exactly.
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For example, one of the things
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that you often hear people say is we have to become an interstellar species because we must leave Earth, right?
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One day the sun's going to go red giant.
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Well, that's true.
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But look at it like this.
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Here's another one of my scientific wild ass guesses.
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If you have the ability to be an interstellar species, you don't need to leave your solar system.
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okay right you can just go right out there to titan build your own suns i .e fusion reactors
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and keep on harvesting energy you don't need the sun anymore better yet move earth
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that sounds more monumental than packing up a billion people
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and shipping them to a moon of jupiter and pitching tent
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and rebuilding civilization i think it'd be way easier to move earth in fact Like they do that.
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Wait, wait, who said a billion people?
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There's a film series made in China called Wandering Earth, which is exactly that.
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I'm looking that up, that sounds good.
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Wandering Earth, you gotta look at the second episode, which is where they actually, the first one is, I don't know what it is,
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but second one, they put rockets that's strategically placed on Earth, and Earth goes, what it does,
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it doesn't go to a bigger orbit, it goes to another star system uh earth becomes the spaceship
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interesting yeah very interesting i'd like to see how they did
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that okay all right well we got to get to some questions
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and of course as always thank you to the patreon members for your financial support
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that allows you to submit these questions
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which also allows us to do many other things with star talk Let's go to Patrick.
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Hi, Hakeem, Dr. Tyson.
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Patrick, just another science nerd from Southeast Texas here again.
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And why do we exist?
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You traced the chain of events that made our existence possible.
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Do you think that chain points towards increasingly deeper layers of emergent organization?
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Or do you believe physics will eventually reach a truly fundamental level beyond which there is no deeper explanation?
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Ooh, I like that. so
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when you go turtles all the way down is there a
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point where it's just hey man we don't even know you know it seems like
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that question went in both directions at the same time it
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kind of did it sounds like it was like where it's going
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and what it is at this deepest most fundamental level
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because in a book i describe the deepest most fundamental level
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i it seems to me the evidence points to the same thing
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that allegedly albert einstein said or believed at one point
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which is the only thing that exists are these fundamental quantum fields and energy right and so again
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i also say and this is one of the things i say in the book where i differ
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and diverge from the community like a lot of people think that space and time are emergent and if
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Energy and fields are required to be fundamental which in this inflaton model of the universe they are a
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field requires a geometry and Energy requires time because it makes change which requires a before and an after Right,
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so if you have those two fundamental quantities you also have space and time existing as fundamental within our universe Okay
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Does that answer the question?
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If you go all the way to the bottom, that's what you got.
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Space, time, energy, and feelings.
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So you don't think there's anything remaining to be discovered or gleaned beneath that level?
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Yes.
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What?
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Context.
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Okay.
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Above that level in the other direction.
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Here's what I mean by that.
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Here's one of the mind experiments.
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Before you go on this further, Hakeem.
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I have to ask you this because sometimes I get this impression.
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Yes, yes, I am.
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Do you smoke weed? On, like, every, like.
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Now, you read my memoir, Chuck.
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I did.
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You read my memoir.
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I did, I did.
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You mean today?
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No, no, I'm joking, man.
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Are you asking me that I just vape at LaGuardia?
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Is that what you're asking me?
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That's hilarious.
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No, go ahead.
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Back to what you were saying.
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Coincidentally.
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Go ahead.
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Let's get back to the fundamentals seriously let's get back to context
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so space and time would be fundamental space
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and time is fundamental not emergent not emergent if quantum fields
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which require a geometry choose your dimensionality you must have a geometry yeah
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but that makes sense the quantum field thing
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that totally makes sense for fundamentals yeah and
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if you have energy you have to have time even quantum
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mechanics shows you the the the fundamental nature marriage of energy and time so you so Therefore, therefore, what was the question?
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Back to that weed.
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Fundamental.
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So energy makes time fundamental.
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So here's the thing.
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I get it.
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So you're separating them off.
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If you accept that energy is fundamental, you must therefore accept that time is fundamental.
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Because of change.
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All right.
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Because energy is a changed state.
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Now, let's move that to what's beneath that and above it, which is context, how, and what's that mean?
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Well, here's, suppose you were to study, when we talk, we teach observational astronomy to students, you know, people don't walk in having a cosmological perspective.
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So we try to give them my way of analogy of perspective.
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So one of the things I used to say is, is that just like the cell is the fundamental building block of the body,
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the galaxy is the fundamental building block of the universe then one day I said well what
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if I take that seriously what if I shrink myself down so small
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that the size of a cell to me is the same
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ratio 20 orders of magnitude as a ratio of me to the size of my galaxy
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and then I studied my universe from
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that perspective what would I do I would do what Hubble did he looked around
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and say oh there are these things called galaxies they come
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in different types spiral elliptical dwarf right I look around there's
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different cells blood muscle bone right then i'd say hey you
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know they have internal structure a bulge arms right i'm like
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oh they got you know what the hell is in a cell a golgi body a nucleus uh
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riboflavin no that's not it ribosome ribosome mitochondria there you go is a mineral vitamin on the on the cereal box
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but then you can zoom out
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and you see we discover the large -scale structure right there's the cosmic web
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and you would do the same thing but after doing all
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that would you have any idea if you're in a whale
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if you're in a horse if you're in a tree right i mean
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if you're seeing muscle bones you're definitely not a tree
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but the point is you can't get the context of your
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of our existence from the inside of the damn animal oh
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wow okay damn you know can the unborn child know what its mother looks like.
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Ooh.
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Well, if you ask any Christian, yes.
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I'd have been in a lot of churches.
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I don't know where that comes from.
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I don't know what it is.
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No, no, I'm joking.
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But, um, okay, that is really.
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So that's what you mean by context.
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That's the context.
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We don't know.
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We don't understand the context.
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And it's definitely not a bauble on a cat's necklace.
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Hakeem, I gotta give it to you, man.
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That's profound found you mean you mean the galaxy on the belt of Orion right right that's a great example
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and the belt was a necklace the little pendant on the on the collar correct
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that was the belt of Orion Wow
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so cool man all right here we go let's go to
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some guy two three three four well that's what he put Hey, Neil, Lord Nice, and Dr. Oleshee.
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Lord?
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He's Lord.
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Oh, you didn't know?
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You didn't know that?
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No. Yeah.
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He says, I'm Graham from Marina Del Rey, California.
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Long -time listener and a first -time caller.
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I recently learned about a millisecond pulsar whose equator moves at nearly a quarter of the speed of light.
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Imagine two indestructible astronauts, one standing at or near the pole and one on the equator.
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What would each see when they look towards each other?
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Rotational speeds would be much faster at the equator, so how would relativity show up for these, probably quite dizzy, observers?
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A fun analogy, if Earth were somehow rotated that fast, could familiar landmarks appear in places that seem impossible because of relativistic effects?
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That's the second question.
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Thanks so much, and you make astrophysics fun and accessible.
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The first question is blowing my mind right now.
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Now, pull an equator, but a pulsar, relativistically, what would they see?
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This reminds me of that old joke.
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What's the last thing to go through an insect's mind when it hits your windshield?
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What?
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It's ass.
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That's not bad.
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Place you on a neutron star, bro, and you're going to be a puddle.
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She gave us a very good qualifier.
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Which was? to indestructible astronauts yes okay so they are able to maintain their perspective
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and their physical integrity while one is at the pole okay
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and one is at the equator of the pulsar all right
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so one is definitely spinning faster because it's at the equator
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if you're rapidly spinning does rapidly spinning create well here's here's the question
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so this is a calculation one right
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because relativistic effects show up at extremes of speed and gravitational energy
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so on a neutron star you have both a rapidly rotating neutron star
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so then the question becomes what are they looking at are
505
they looking at the distant universe are they looking at each
506
other what they're looking at each other they're looking at each other
507
so that means that this body is typically like we're talking like 10 miles
508
or something across
509
so you're not going to look at each other unless you're
510
super tall okay they're beyond each other's horizon okay they're beyond each other's horizon
511
and if you're super tall you're not in well you're indestructible
512
but doesn't pay to be super because that's the thing right
513
if you're on a super earth the body the it doesn't make gravity the lower you're gonna be okay
514
so um but I guess the question they're getting
515
that is you know it's one of those like how much is space -time curved
516
and what would be the effect of your light is traveling to me you're no longer there
517
and then the next bit of light is coming
518
and the next bit of light is coming the next bit of light is coming right
519
and their paths are kind of something weird right
520
so you're going to be distorted and smeared yep is my guess there you go
521
because the light rays are not coming as one color image they're being smeared out yeah
522
and then you get a whole blur
523
but they're coming from a weird angle too right right yeah
524
so basically you just it's going to be a mess is
525
what you're going to see you're going see a little mess yeah
526
and by the way you have to do that on the pulsar
527
because anything else its gravity isn't strong enough to hold it together as one object right
528
while spinning that fast exactly which spin itself apart right yeah right yeah
529
so pulsars can do that yeah that was a great question there man
530
that was really cool who again uh some guy two three three four that's it didn't even give a name.
531
Hey, some guy.
532
This is Charles Coel, who says, aloha from Honolulu.
533
Hi, Dr. Tyson, Lord Nice, and Dr. Olesje.
534
Could Schroeder's cat and the Cheshire cat have a kitten?
535
Although the lightest primordial black holes have been ruled out as dark matter or dark gravity, as Dr. Tyson prefers, because they evaporate too quickly.
536
Could they still leave something behind, like a Cheshire cat's smile.
537
When Hawking radiation separates the very last virtual particle pair at the event horizon and the black hole winks out of existence,
538
could the breaking of the final entanglement leave a topological scar,
539
not mass, not energy, just a knot in space time that was never there before.
540
I think these people are smoking more weed than either one of us.
541
This is insane.
542
And that last sentence about, give me that last sentence again.
543
He said, not mass, not energy, just a knot in space time that was never there before.
544
This sounds a lot like the so -called topological defects from the early universe.
545
But the scenario in which they're generated is, so basically what they're saying is, is.
546
do a gr calculation right model the evaporation of the black hole and then from that can you
547
derive the metric that's left over right the the the space -time configuration that's left over okay and
548
if it has fully evaporated by definition a space -time metric
549
only um exists in the presence of a mass energy density
550
or pressure right so it sounds like the answer would be a no
551
but at the same time you know this is gonna be a little bit controversial maybe
552
but there's a lot of stuff we predict
553
and then we see it we're so good at that right
554
but not everything
555
that pops out of the equations comes to fruition right it
556
you know sometimes people play with equation in such a way
557
and they find something interesting and it turns out a little explainer on
558
that yes we did oh yeah we had the equations
559
that have solutions yeah
560
that don't have any correspondence to exactly to the person who who might need
561
that for right right so with
562
that being said you know we've not actually observed black hole evaporation right right
563
and you know makes sense everything you know all the gr
564
stuff is being found exactly as predicted to high precision
565
so i have no reason to say gr is crap
566
but for a physical phenomenon that has never been observed
567
and to then to speculate what would happen right that's a lot of the conversation in physics these days
568
and I think that you know black holes get more attention than they deserve in
569
that type of discussion right I think there is a practical
570
universe discussion on black holes catching shade on black he really
571
is like I didn't think they could get any black well they no longer swim
572
helps that right so okay so we want to speculate on the speculation
573
and the speculate you know it's too many layered speculations for
574
me I got you yeah yeah all right well yeah okay well thanks a lot for
575
that one Charles this is Marion who said hello dr. Oleshay
576
dr. Tyson Lord nice Marion from Pennsylvania my question is since
577
dr. Oleshay was first on StarTalk I believe five years ago
578
wow she's keeping track um what's the most interesting discovery about
579
the universe you have learned since then also what do you think of the recent proposal
580
that the ancient little red dots are now globules where massive stars are born thanks it's all good
581
so it's all good so yeah the first part of
582
that yeah intrigues me so what do you how do you take
583
that so um since then i've studied a lot biology
584
and a lot of geology here is i i you know i wish i could channel you man
585
and what we started out talking about
586
that like the about the uh stars making stardust i want
587
to describe in such the same way the origin of the vertebrate
588
because i went around telling everybody
589
because one day i had a realization i was like wait a minute
590
because i have i i have a medical condition
591
that brought me to this realization there's a tube that goes from my mouth to my exit okay i'm a worm
592
with just some appendages right some locomotion some defense right like
593
we're all worms right i was going around telling all my friends and family's laughing hey we're all worms
594
right and then one day i thought you know what what is the real origin of vertebrates
595
do you know the origin of vertebrates no those fish no no no pre -fish the origin the pre but
596
so it's it's chordates right it's it's the note of chord
597
before there's a bone wrapped around it is just the chord
598
so where did it come from we're a freaking filter feeder bro
599
so these little filter feeders like corals these little lemones
600
when they're in their larval stage they go around they taste
601
little spots to figure out where they want to sit down
602
and so they look like a little sperm cell they're a little globular tadpole with a little tail right
603
so to power that tail they had a little nerve going down it to power those muscles
604
and then eventually they decided you know what i'm gonna skip my adult phase
605
and eventually it becomes the the first notochord and then the coronates
606
and then you get a um from that yeah a backbone
607
and then there is the new dna data on race
608
which is now all over youtube right
609
so we all had the story oh ultraviolet light that's what makes Skin color this
610
or that and the old story was right
611
that the evolution of light skin depigmentation happened from 40 ,000 years to 20 Thousand years ago.
612
No, it started 8 ,000 years ago due to agriculture right agriculture created depigmentation and
613
5 ,000 years ago Europe was only 50 % depigmented.
614
Mm -hmm.
615
That's 3 ,000 years ago, so we're talking like 1 ,000 BCE, man.
616
At this point, the freaking pyramids are already 1 ,500 years old.
617
So when you look at these ancient, you know, Europeans 40 ,000 years ago, you find the oldest math in Germany, in Europe 40 ,000 years ago,
618
and you think, oh, it's the ancient Germans.
619
Bro, they're not, they're brown.
620
Yeah.
621
You know, there's going to be a lot of Germans who are upset with you right now.
622
I was just hanging out with Germans and they've changed they've changed
623
so i've been told okay yeah you're thinking the older
624
but anyway this is all mind -blowing research yeah pop quiz
625
how many miles above the earth's surface does the international space station typically orbit that's right it's about 250
626
which also happens to be the number of reasons to choose
627
t -mobile here's an excellent reason they have the fastest 5g home internet according to ukla speed test
628
which you can test for yourself worry free with their money
629
back guarantee it sounds like a no -brainer another great reason it's fast
630
and easy to set up to plug it in
631
and you're online in virtually no time with no appointment no
632
technician needed those are just a few reasons find yours at
633
t -mobile .com home internet where you can check availability
634
and try it for yourself they're
635
so sure you'll love it you can get your money back
636
if you don't fastest according to ukla speed test intelligence data
637
second half of 2025 all rights reserved redeem money back guarantee within 30 days of cancellation all right
638
so that's the so biology is your big fascination now
639
so the second question and geology because another thing about geology
640
that is little appreciated is the fact
641
that our freaking outer core is liquid bro liquid metal right
642
so from like 19 % radius out to like 55 %
643
the earth's interior is liquid metal yes liquid metal that's the core we're on a freaking what is
644
that cake you cut it in the lava oh it's a
645
lava cake yeah earth is a lava cake yeah that's cool
646
we're like a nut in the middle right bro yeah well
647
that's cool people think the ground beneath our feet of solid no well
648
and guess what it the great thing about that is
649
if it wasn't we wouldn't be here exactly because
650
that is what gives us the magnetic field
651
that protects us all yeah very cool all right
652
so here's the second thing she said also what do you think about the recent proposal
653
that the ancient little red dots are now globules where massive
654
stars were born okay uh my understanding is based on the latest paper they see
655
that the sources of the light from those globules is reprocessed light from an accretion disc
656
so it looks like it's a baby super massive black hole with an accretion disc in there
657
and so there's um what is it called where you know uh you see scattered light
658
and you see uh what is the word phosphorescent what the hell is it called it's polarized it's polarized
659
so it's absorbed and re -emitted by the gas
660
so you essentially have oh okay yeah i didn't understand okay i didn't understand you at first
661
so super massive black hole accretion disk accretion is emitting high
662
energy radiation that'd be emission nebula where the atoms are charged up
663
and then they exactly charge and they re -eminate exactly
664
because okay that's plus scatter light like coming down directly from
665
the disk they just got yeah gotcha all right just to remind people what are these red things
666
so it looks like it is a baby super massive black
667
hole being born in the very very very early early universe
668
right yeah in the dark ages in the dark ages
669
so the question that we've been having is
670
which came first the super massive black hole
671
or the galaxy that's been an eternal question internal question it's looking like it's the hole wow dude
672
so that's super cool man the hole precedes the dirt right
673
that's
674
so cool the reason why it's not entirely obvious right is
675
a super massive black hole might have a billion times the mass of the sun yeah
676
but the galaxy would have a hundred billion times the
677
so the black hole is less than one percent so how are you going to get everybody to join this
678
so it's it was not a completely obvious pathway okay yeah
679
to know who came first right yeah in this yeah that's fascinating yeah
680
that is really cool man i did not i did not
681
okay chuck we have time for one last question one last
682
question here we go tristan phillips says hello neil chuck hakeem
683
i hope you're all doing swell uh coming from jensen beach
684
florida here i have what may be the most important unanswered
685
question in astrophysics let's say i somehow acquire a completely indestructible
686
16 pound brunswick bowling ball it's immune to heat pressure radiation
687
basically everything i gently place it on the equator of the
688
fastest spinning pulsar we know of let it rotate with the star
689
and then through the power of plot armor i magically turn
690
off the pulsar's gravity just long enough for the bowling ball to escape.
691
Okay.
692
Did I just throw the fastest strike in the history of the universe?
693
And how fast is that bowling ball actually leaving?
694
If that's not ridiculous enough, let's say I somehow recover the bowling ball, take it over to a supermassive black hole and launch it into one of its relativistic plasma jets.
695
Once it's far enough away that it escapes the black hole's gravity and won't end up orbiting anything, how fast is it moving now?
696
Two different scenarios, but i like the first one better you basically use a
697
pulsar as a catapult with an indestructible bowling ball sitting at the equator it's spinning spinning spinning
698
when it gets to a terminal velocity you stop it boom
699
it goes off how fast is it going well at first it's going the speed of the spin right okay
700
but it has to climb out of that gravitational well of
701
that neutron star there you go
702
but she said she said she turns off the gravity oh cuz cuz it's okay
703
so she turns off the gravity turns off the graph yeah
704
this is a powerful being we're dealing oh I love it did she say turn off the ground
705
so you know what's really interesting is
706
that I saw someone who actually modeled this cuz you know the idea
707
that we always have you have something spinning
708
and you let it go it takes off on this tangent line yeah right
709
and they found that actually it doesn't at the very beginning there's some little glitch thing
710
that happens i don't remember the details uh
711
and then it goes on a straight line um
712
but conservation of momentum that sucker's gonna it's just gonna go yeah so uh
713
so typically a fast spinning pulsar the equator's moving at some
714
appreciable fraction of the speed of light right like half the
715
speed of light maybe a quarter speed i have no idea
716
so the ball goes off at that speed that's right that's all that's pretty that's I mean,
717
that's a pretty ornate way to just say what happens if the ball goes at half the speed of light.
718
Right, right.
719
But you know what it reminds me of?
720
That new launch company that spins the...
721
Oh, yeah, it's a...
722
The centrifuge rocket thing?
723
Yeah, it's a...
724
What do they call it?
725
Yeah, I mean, in fact, I saw some old sci -fi movies where they had a mechanism like this.
726
Before they figured out multi -stage rockets, deep in the 50s, before we had
727
that going right yeah it was it was a spinner
728
and then they deconnect they detached it and then shoot it through a tube
729
and it goes yeah
730
and then it goes out that'd be kind of cool though
731
yeah they're they're doing it yeah it's fun to think about
732
you know i mean i like it yeah all right okay
733
man you are like i'm tired i mean damn it's
734
so cool having you here man no it is no man that was full Full stop.
735
It's so cool having you here.
736
Thank you, man.
737
It's good to be true in person, man.
738
You're brilliant.
739
People know it, too.
740
It sounds like half of him is in this book.
741
Why do we exist?
742
Like, you open it up, he pops out.
743
The nine realms of the universe that make you possible.
744
And one of them has to be Asgard, because that is a realm of the universe.
745
I think you missed an opportunity.
746
I got one thing I got to say.
747
I'm not a Marvel fan.
748
Oh, but I am, but I am, but I am.
749
Okay, good.
750
But I have one thing I have to say about the Astronomical Society of the Pacific, and that is we have just launched a YouTube channel called Astrobeat, where I do explainer videos.
751
It's about time.
752
It is.
753
Because the mission is to spread the love of the universe far and wide.
754
That's right.
755
And even though it's called of the Pacific, that's just, it's incidental that it's on the West Coast
756
outside of San Francisco our new DBA doing business ass is the Astro Society
757
so that's been our website forever astrosociety .org
758
so the YouTube channel is the Astro Society
759
so in the future all ASP things
760
that don't have to do with the publications
761
and the awards gonna be labeled as the Astro Society
762
and I'm a huge supporter of their work
763
because it makes my job easier and he is appreciated that's awesome all right Thanks for coming through town.
764
Thank you for having me.
765
I'm honored again.
766
How do we find you?
767
Are you anywhere on the internet?
768
I am not
769
But you can find me at the Astro Society org you
770
find us we have all our Social some I'm on the socials of the Astro Society these days.
771
Okay, and occasionally you come through town and help out the history channel Absolutely, I help out the history channel.
772
I help out Nova.
773
We work together.
774
Yeah.
775
Yeah.
776
All right.
777
That was great That's all the time we have this has been start talking another Cosmic Queries,
778
the Hakeem Ulishayi edition, Neil deGrasse Tyson, Four Star Talk.
779
As always, I bid you to keep looking up.
780
All right, we got it there.
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Vocabulaire et conseils d’expression pour cette leçon
Cette vidéo contient 780 phrases et 7689 mots à répéter en shadowing. La partie parlée dure 49:40. Le locuteur parle à un rythme naturel d’environ 155 mots par minute, proche d’une conversation courante. 82 % des mots font partie des 3 000 mots les plus courants en anglais ; le reste mérite d’être vu avant de commencer.
Vocabulaire clé de cette vidéo
15 mots de la vidéo à retenir, avec leur prononciation et leur sens :
| Mot | Prononciation | Sens |
|---|---|---|
| fundamental adjectif | /ˌfʌn.dəˈmɛn.təl/ | fondamental |
| spin verbe | /spɪn/ | tournoyer, pivoter rapidement |
| equation nom | /ɪˈkweɪ.ʒən/ | équation |
| galaxy nom | /ˈɡæl.ək.si/ | galaxie |
| horizon nom | /həˈɹaɪ.zən/ | horizon, ligne d'horizon |
| gravity nom | /ˈɡɹævɪti/ | gravité |
| cosmic adjectif | /ˈkɑz.mɪk/ | cosmique |
| quantum nom | /ˈkwɑntəm/ | quantité |
| plasma nom | /ˈplæzmə/ | plasma |
| liquid nom | /ˈlɪk.wɪd/ | liquide |
| magnetic adjectif | /mæɡˈnɛtɪk/ | magnétique |
| inform verbe | /ɪnˈfɔɹm/ | informer, renseigner |
| bone nom | /boʊn/ | os |
| muscle nom | /ˈmʌs.əl/ | muscle |
| remind verbe | /ɹəˈmaɪnd/ | rappeler à |
Les verbes à particule que vous entendrez
| Mot | Prononciation | Sens |
|---|---|---|
| look around verbe | regarder autour de soi | |
| help out verbe | dépanner | |
| turn off verbe | éteindre | |
| figure out verbe | cerner | |
| go ahead verbe | /ˌɡoʊ əˈhɛd/ | vas-y, allez-y |
| zoom out verbe | /ˌzuːm ˈaʊt/ | dézoomer |
| come down verbe | descendre, tomber | |
| come up with verbe | inventer, imaginer |
Prononciation à surveiller
Le locuteur utilise 190 contractions et formes réduites, comme you're, don't, they're. Prononcez-les sous leur forme courte, telles que vous les entendez.
- Les sons « th »: hypothesis /haɪˈpɒθɪsɪs/, beneath /bɪˈniːθ/, mathematics /mæθ(.ə)ˈmæt.ɪks/
- Les sons « sh » et « zh »: equation /ɪˈkweɪ.ʒən/, radiation /ˌɹeɪ.diˈeɪ.ʃən/, fusion /ˈfjuː.ʒən/, ratio /ˈɹeɪ.ʃoʊ/, essentially /ɪˈsɛnʃəli/
- Mots longs — placez bien l’accent: fundamental /ˌfʌn.dəˈmɛn.təl/, radiation /ˌɹeɪ.diˈeɪ.ʃən/, hypothesis /haɪˈpɒθɪsɪs/, differently /ˈdɪf.ə.ɹənt.li/, geometry /d͡ʒiˈɑ.mə.tɹi/
Comment s’entraîner avec cette vidéo
- Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
- Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
- Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme fundamental, spin, equation.
La grammaire de cette vidéo
Les structures que le locuteur utilise le plus, avec les mots exacts de la vidéo :
| Structure | Dans la vidéo |
|---|---|
| Present perfect continu have/has been + -ing — une action commencée avant et toujours en cours | have been moving · I've been telling · I've been thinking |
| Phrases conditionnelles if + proposition, will/would + verbe — une condition et son résultat | if it wasn't we wouldn't be |
| Present perfect have/has + participe passé — une action passée qui compte encore maintenant | you've also associated · I've done · you've been |
| Voix passive be + participe passé — l’accent est mis sur ce qui arrive, pas sur qui le fait | is based · were separated · is written |
Qu'est-ce que la technique du Shadowing ?
Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.