Prática de Shadowing: Why Do We Exist? With Hakeem Oluseyi - Aprenda a falar inglês com vídeo
Criando lição...
1
just like the cell is the fundamental building block of the
2
body the galaxy is the fundamental building block of the universe what
3
if i shrink myself down so small
4
that the size of a cell to me is the same
5
ratio to the size of my galaxy what would i do i would do what hubble did he looked around
6
and say oh there are these things called galaxies they come
7
in different types i look around there's different cells blood muscle bone right
8
but then you can zoom out
9
and you see we discovered the large -scale structure right
10
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.
11
You can't get the context of your existence from the inside of the damn animal.
12
Can the unborn child know what its mother looks like?
13
Ooh.
14
Space fact.
15
Dark matter is 85 % of all the gravity we measure in the universe, and we don't know what's causing it.
16
It doesn't interact with our light.
17
It doesn't even interact with itself,
18
which means it cannot coalesce to form solid objects like stars or planets or people.
19
This is StarTalk.
20
Neil deGrasse Tyson, your personal astrophysicist.
21
Chuck Nice, right next to me.
22
What's up, Neil?
23
All right, man.
24
How are you, buddy?
25
Doing good?
26
Doing great.
27
We've got a Cosmic Queries today.
28
Yes, we do, inquiring minds want to know.
29
Indeed, and in fact, it's on cosmology as a topic.
30
It is the expertise of our guest.
31
Third time on StarTalk?
32
Yeah!
33
I think so.
34
That's right.
35
Hakeem Ulusheye.
36
Thank you so much.
37
And it is the fourth time.
38
Fourth time!
39
Oh, that's right, because this...
40
Yeah, no, wait, fourth time?
41
Memoir, Cosmic Queries, both remote, and then finally...
42
Oh, you know, remote, that's right.
43
Yeah, it kind of messed me up.
44
Well, we got an astrophysicist cosmologist, which is a subdivision of all astrophysicists who thinks about the origin,
45
evolution, and fate of the universe.
46
Ooh.
47
Right.
48
Plus, he's been practicing my open for this show.
49
And I don't know if I should be happy about it or kick his ass later.
50
Let me hear it.
51
Go.
52
Let's see.
53
This is StarTalk.
54
You know, that's pretty good.
55
Not bad.
56
Gotta tell you.
57
You know?
58
Right now, with three black guys up here, I don't know who's who.
59
Wait a minute, wait a minute.
60
I wanna get back to this kick -your -ass comedy.
61
That's hilarious.
62
So you're a host of the podcast Particles of Thought.
63
I love that title.
64
And it's a NOVA podcast.
65
It's a NOVA podcast.
66
PBS NOVA, GBH, out of Boston.
67
Very good.
68
Very nice. And CEO.
69
How many people get to say they CEO?
70
Because you CEO, you the man.
71
That's right.
72
CEO of the Astronomical Society of the Pacific.
73
Very nice.
74
And I'm going to ask you about that in a minute.
75
And you've also associated with NASA's IMAP satellite.
76
Yes.
77
Remind me what IMAP stands for.
78
Interstellar Mapping and Acceleration Probe.
79
Nice.
80
Who's accelerating?
81
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.
82
Right?
83
And those generate neutral atoms that come back into the solar system and they get measured by IMAP.
84
Wow.
85
Yeah, okay, all right.
86
And may I ask, why?
87
And if you're worried about the sun, that doesn't sound very cosmological.
88
It doesn't.
89
How do you stitch that together?
90
Because I started out doing instrumentation and calculations, computational, and understanding plasmas really well.
91
So it's kind of like I have this toolbox that I can travel from field to field with, right?
92
So I've done propulsion.
93
Because plasma is everywhere in the freaking universe absolutely oh my
94
god yeah tell people we're not talking about blood plasma no we're kind of like I forgot about
95
that yeah yeah it's a whole other kind of plasma
96
so this is when you take a gas heat it even more you break more bonds right
97
and you break the solid to liquid bond liquid to gas now once you're a gas you're just molecules
98
or atoms you start breaking those apart
99
so once you break apart electrons from atoms you now have a plasma yeah it's an electron soup
100
And so this gas will respond to magnetic fields.
101
You can do really cool things with it, including feed a fusion reactor for the future of energy.
102
Very nice.
103
That's where anybody's going to go.
104
Yeah.
105
And that'd be the only way you would be able to hold the energy, is in a magnetic field bottle, right?
106
Not necessarily.
107
No?
108
Really?
109
What the hell else?
110
You can also put it in a little pellet, enclose it in a metal, and blast it, generating x -rays that create fusion.
111
Oh, but that's not a...
112
I'm sorry.
113
I was thinking fusion.
114
That's not a plasma.
115
You're starting with a little seed, right?
116
Right.
117
But yeah, so if you're going to confine a plasma, you're going to do that with magnetic fields.
118
Okay.
119
Yeah, a magnetic bottle.
120
So you were right.
121
You were on the cast.
122
Totally on the cast.
123
Yeah, you totally shook my confidence there.
124
Last you were here, you've been busy, and you wrote a book.
125
I did.
126
A book with the audacious title, the bodacious title, the out of this world title, why do we exist?
127
Wow.
128
The nine realms of universe that make you possible.
129
Mm -hmm.
130
This sounds very Asgardian.
131
So wait, the realms.
132
That's right, the realms.
133
Yeah, that's right.
134
So you say they make you exist.
135
Does that mean, because you're speaking to the reader, does that mean you have a different point of origin?
136
Because otherwise that word really should be a we.
137
Just saying.
138
I think it is a we.
139
Why do we exist, the nine realms of the universe that make you possible?
140
That's right.
141
That's right.
142
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.
143
Gotcha.
144
Okay.
145
Okay.
146
Tear a new one right there.
147
That's what that...
148
Okay.
149
That sums it up, because I've said those words many times.
150
And sometimes you might hear, you mean our son?
151
Yeah.
152
So what is a realm?
153
So in this case, what I do is I listen to what the universe told me, and I report on it.
154
Essentially, what I realized as a physicist is that when you study the universe, we typically do it in this disjointed way right
155
but there is a cohesive story
156
but what the average person doesn't understand is how the rules
157
that that our intuition gives us just doesn't scale
158
and the universe as it scales the rules change fundamentally
159
so you have to really start looking at the universe completely differently
160
so here we're in the middle realm i call the middle realm bigger than an atom
161
or molecule smaller than a galactic arm right it's middle earth
162
like yeah exactly what about second breakfast are you going to the shower what happened
163
so anyway the cosmological realm right
164
so now the dynamics of space -time dominate in the middle realm the dom you know
165
and what dominates is based on the flow of energy through
166
that realm so what you see the trend is is energy is constantly leaving matter going from
167
and it's really a story of quantum fields going from the
168
matter to fermionic quantum fields into the electromagnetic quantum fields
169
so every day there's more photons than there were the day
170
before there's less energy in matter right ultimately leading to this
171
heat death right the long time in the future now we go
172
if you study the cosmological realm you realize something ain't right
173
that leads you to the dark
174
so these are energy realms in a sense well no they're they're realms of emergence as well right
175
so when you go to for example the temporal realm the story of how time unfolds
176
but listen in other realms there are still unfoldings in the middle realm I discuss how stars
177
and planets come into existence in the realm of life we talked about a biogenesis and how
178
that leads ultimately you know through this energy ladder from chemo
179
synthesis to you know anoxic photosynthesis to oxygenic photosynthesis to oxygenic respiration right this energy ladder
180
that leads to a brain like yours okay yeah absolutely Yeah, exactly.
181
And then you have the realms beyond horizons, beyond our cosmic event horizons, within the black hole event horizons.
182
Okay.
183
That's unknowable.
184
Yeah.
185
And then you have the multiverse.
186
So now when you look at the cosmic microwave background radiations, super horizon signature, that seems to indicate that inflation occurred.
187
Is that just the edge of the observable universe?
188
What's the super horizon?
189
I don't know that if you look at the tt spectrum of the cosmic microwave background radiation
190
which you get from looking at the sizes of these yeah
191
you'll see to the beyond the biggest lump there's a dip right
192
and that's known as the super horizon fluctuation okay so
193
when you look at the inflationary epic of the universe okay
194
right you have a situation now where our boundary the cosmic event horizon is moving out outwards right right
195
but at early times during inflation right it could have been moving inwards
196
and so areas that were separated
197
that were within your you know outside your horizon now would have been inside your horizon
198
so you can get these bigger fluctuates you know I screwed up
199
when I when I described the Andromeda paradox here slightly even though the world now knows it Thank you.
200
Thank you.
201
Thank you.
202
Thank you.
203
Thank you.
204
Thank you.
205
Thank you.
206
Thank you.
207
Thank you.
208
Thank you.
209
Very differently motivated when you read it, you'll be like so you're saying the information
210
that was unavailable to him You took and use that as the basis for your equation.
211
Not exactly.
212
Okay, here's what I did I started my equation.
213
He started his his equations is written in many ways in terms of outcomes life is formed a
214
Civilization forms technologies forms mine is around the drivers for life, right?
215
so if you look at the just right stars what defines a just right star it has to have
216
that right exactly now what defines a just right planet that's that's valid what you're saying is very valid okay
217
so it's the only shahey equation inspired by the drake equation
218
and the seager equation i'll have to add right
219
because sarah seager from m .i .t also came out with an equation i know
220
but a big uh planet person yeah okay yeah all right and now astrobiology yeah yes yes
221
very cool well that's that's excellent yeah man
222
so they're going to come away with a cognitive map of reality
223
that will allow them to okay so so
224
so i think i i spoke wrong about it what you're saying is we'll read the book
225
and then come away reflecting absolutely absolutely yeah read the reviews
226
that's what you know it's like wow this is something different to think about
227
and then when the physicist here's the thing you're gonna like
228
so you're different from the average person because you've heard it all
229
and you're probably at a point now where you've probably heard it all
230
so you have a new perspective see that's what i love about you man
231
when i first met you you didn't meet me but
232
when i first met you i was like man like the thing you did
233
that went super viral where you're talking about the stars
234
when somebody asked you yeah they asked me what's the most mind -blowing fact exactly
235
yeah as an astronomy dude it's still going viral i'd heard
236
that i had heard this you know we all hear
237
that young right yeah but i never heard it like
238
that i never heard nobody made me feel it right you know I'm saying
239
and so I think this particular provocation is gonna hit hits in a different way for physicists like
240
that got it because you've seen it all
241
and now somebody comes at it from this other angle
242
and you're like oh I see what you're saying
243
so you're taking information
244
that we already thought about in bits you put it together in a new way
245
and there's new material yeah there's a lot of new original things
246
that bit you think it was called the most astonishing fact I was asked by Time magazine sitting in this chair Really?
247
It had a long interview.
248
He said, what's the most astonishing fact?
249
And then I had to think about it for a moment.
250
Then I delivered an answer, which then other people plucked and then put B -roll visuals behind it.
251
And that's what really took off.
252
Not just me sitting here delivering the answer.
253
Okay.
254
Yeah.
255
Okay.
256
So that's a noble goal.
257
It is.
258
It is.
259
It is.
260
All right.
261
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.
262
That makes President Trump's proposed U .S.
263
Space Academy an interesting extension of that idea.
264
His August 28th order created a commission to develop plans for a NASA -led federal academy focused on training future space leaders.
265
But the coverage shows just how differently that future can be interpreted.
266
Over 250 outlets covered the story with varied opinions and Ground News lets us step back and see those differences clearly.
267
Left -leaning coverage tends to focus on questions about cost, structure and whether the Academy is necessary,
268
while right -leaning coverage more often frames it as a bold investment in American space leadership and competition.
269
Same story, different framing.
270
That's why we've partnered with Ground News for years.
271
Ground News brings reporting from more than 50 ,000 sources into one place and shows you the bias, credibility and ownership behind the coverage.
272
Their Blindspot feed also services stories getting disproportionate attention from one side of the political spectrum,
273
giving you a better sense of which stories may be missing from your usual media diet.
274
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,
275
or by scanning the QR code on the screen.
276
So there's an acronym associated with you called SWAG.
277
SWAG.
278
Of course there is.
279
SWAG.
280
As an acronym, how do you get that?
281
How do you get those letters?
282
That's a scientific wild -ass guess.
283
Wild -ass guess.
284
I like it.
285
What a scientist.
286
That's black for hypothesis.
287
No!
288
Informed hypothesis.
289
Informed hypothesis. So tell me.
290
Give me an example.
291
What's that?
292
Well, everything I've been telling you.
293
I tell you right in the book.
294
The whole book is my swag.
295
I got you.
296
This is a scientific, wild -ass guess, but it's highly informed, right?
297
I've been thinking about this.
298
Okay.
299
But normally, like, you write a paper, get it published, peer reviewed, and then a book comes after that.
300
That's right.
301
Yeah, yeah.
302
Well, this is not that kind of work.
303
This is not for them.
304
So, you know, I've been in a world of the pros forever, right?
305
And, you know, this is for everybody else.
306
Okay.
307
Yeah, but for the pros, too.
308
So, you know, this is not a quantitative study only one tiny part of
309
the book has a couple of equations in it right
310
so there's no data it's an exploration of ideas it's deeper than
311
that man you know it's an exploration of deep ideas deep ideas right
312
but it's also a man it's just so dope so but
313
if we unpack this idea it's anyone could come up with a wild ass guess that's right
314
but not all of them would be scientifically tracked Exactly.
315
So help me understand that distinction.
316
Well, the distinction is if I were going to submit a paper, I would have a hypothesis.
317
Okay.
318
And typically you're going to study some very narrow question, right?
319
This is very broad.
320
And what I'm doing is something that a professional in my position doesn't really normally do.
321
So when a physicist interviewed me, he said, Hakeem, what I don't understand about you, bro, is how are you so courageous?
322
How are you so brave?
323
You just throw out your ideas and you don't care what people think.
324
And that's what I've done in this case.
325
I've, you know, we talk about crazy ideas privately, right?
326
But, hey, I'm putting it out there for the world.
327
Once I snitched on myself in my memoir, I might as well tell you my crazy thoughts about the universe, too.
328
But they're well grounded.
329
Okay.
330
Okay, so these are well -formed, scientifically -based imaginings.
331
Isn't everything an imagining?
332
In many respects, yes.
333
But no, it's not that.
334
I'm a serious empiricist, so I have to stay within the boundary of what we have observed to be true.
335
I have to stay within the boundary.
336
Scientifically informed.
337
That's the scientifically informed part.
338
So if you're imagining what can be within the boundaries of scientific soundness, that's what I'm talking about.
339
Exactly.
340
For example, one of the things
341
that you often hear people say is we have to become an interstellar species because we must leave Earth, right?
342
One day the sun's going to go red giant.
343
Well, that's true.
344
But look at it like this.
345
Here's another one of my scientific wild ass guesses.
346
If you have the ability to be an interstellar species, you don't need to leave your solar system.
347
okay right you can just go right out there to titan build your own suns i .e fusion reactors
348
and keep on harvesting energy you don't need the sun anymore better yet move earth
349
that sounds more monumental than packing up a billion people
350
and shipping them to a moon of jupiter and pitching tent
351
and rebuilding civilization i think it'd be way easier to move earth in fact Like they do that.
352
Wait, wait, who said a billion people?
353
There's a film series made in China called Wandering Earth, which is exactly that.
354
I'm looking that up, that sounds good.
355
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,
356
but second one, they put rockets that's strategically placed on Earth, and Earth goes, what it does,
357
it doesn't go to a bigger orbit, it goes to another star system uh earth becomes the spaceship
358
interesting yeah very interesting i'd like to see how they did
359
that okay all right well we got to get to some questions
360
and of course as always thank you to the patreon members for your financial support
361
that allows you to submit these questions
362
which also allows us to do many other things with star talk Let's go to Patrick.
363
Hi, Hakeem, Dr. Tyson.
364
Patrick, just another science nerd from Southeast Texas here again.
365
And why do we exist?
366
You traced the chain of events that made our existence possible.
367
Do you think that chain points towards increasingly deeper layers of emergent organization?
368
Or do you believe physics will eventually reach a truly fundamental level beyond which there is no deeper explanation?
369
Ooh, I like that. so
370
when you go turtles all the way down is there a
371
point where it's just hey man we don't even know you know it seems like
372
that question went in both directions at the same time it
373
kind of did it sounds like it was like where it's going
374
and what it is at this deepest most fundamental level
375
because in a book i describe the deepest most fundamental level
376
i it seems to me the evidence points to the same thing
377
that allegedly albert einstein said or believed at one point
378
which is the only thing that exists are these fundamental quantum fields and energy right and so again
379
i also say and this is one of the things i say in the book where i differ
380
and diverge from the community like a lot of people think that space and time are emergent and if
381
Energy and fields are required to be fundamental which in this inflaton model of the universe they are a
382
field requires a geometry and Energy requires time because it makes change which requires a before and an after Right,
383
so if you have those two fundamental quantities you also have space and time existing as fundamental within our universe Okay
384
Does that answer the question?
385
If you go all the way to the bottom, that's what you got.
386
Space, time, energy, and feelings.
387
So you don't think there's anything remaining to be discovered or gleaned beneath that level?
388
Yes.
389
What?
390
Context.
391
Okay.
392
Above that level in the other direction.
393
Here's what I mean by that.
394
Here's one of the mind experiments.
395
Before you go on this further, Hakeem.
396
I have to ask you this because sometimes I get this impression.
397
Yes, yes, I am.
398
Do you smoke weed? On, like, every, like.
399
Now, you read my memoir, Chuck.
400
I did.
401
You read my memoir.
402
I did, I did.
403
You mean today?
404
No, no, I'm joking, man.
405
Are you asking me that I just vape at LaGuardia?
406
Is that what you're asking me?
407
That's hilarious.
408
No, go ahead.
409
Back to what you were saying.
410
Coincidentally.
411
Go ahead.
412
Let's get back to the fundamentals seriously let's get back to context
413
so space and time would be fundamental space
414
and time is fundamental not emergent not emergent if quantum fields
415
which require a geometry choose your dimensionality you must have a geometry yeah
416
but that makes sense the quantum field thing
417
that totally makes sense for fundamentals yeah and
418
if you have energy you have to have time even quantum
419
mechanics shows you the the the fundamental nature marriage of energy and time so you so Therefore, therefore, what was the question?
420
Back to that weed.
421
Fundamental.
422
So energy makes time fundamental.
423
So here's the thing.
424
I get it.
425
So you're separating them off.
426
If you accept that energy is fundamental, you must therefore accept that time is fundamental.
427
Because of change.
428
All right.
429
Because energy is a changed state.
430
Now, let's move that to what's beneath that and above it, which is context, how, and what's that mean?
431
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.
432
So we try to give them my way of analogy of perspective.
433
So one of the things I used to say is, is that just like the cell is the fundamental building block of the body,
434
the galaxy is the fundamental building block of the universe then one day I said well what
435
if I take that seriously what if I shrink myself down so small
436
that the size of a cell to me is the same
437
ratio 20 orders of magnitude as a ratio of me to the size of my galaxy
438
and then I studied my universe from
439
that perspective what would I do I would do what Hubble did he looked around
440
and say oh there are these things called galaxies they come
441
in different types spiral elliptical dwarf right I look around there's
442
different cells blood muscle bone right then i'd say hey you
443
know they have internal structure a bulge arms right i'm like
444
oh they got you know what the hell is in a cell a golgi body a nucleus uh
445
riboflavin no that's not it ribosome ribosome mitochondria there you go is a mineral vitamin on the on the cereal box
446
but then you can zoom out
447
and you see we discover the large -scale structure right there's the cosmic web
448
and you would do the same thing but after doing all
449
that would you have any idea if you're in a whale
450
if you're in a horse if you're in a tree right i mean
451
if you're seeing muscle bones you're definitely not a tree
452
but the point is you can't get the context of your
453
of our existence from the inside of the damn animal oh
454
wow okay damn you know can the unborn child know what its mother looks like.
455
Ooh.
456
Well, if you ask any Christian, yes.
457
I'd have been in a lot of churches.
458
I don't know where that comes from.
459
I don't know what it is.
460
No, no, I'm joking.
461
But, um, okay, that is really.
462
So that's what you mean by context.
463
That's the context.
464
We don't know.
465
We don't understand the context.
466
And it's definitely not a bauble on a cat's necklace.
467
Hakeem, I gotta give it to you, man.
468
That's profound found you mean you mean the galaxy on the belt of Orion right right that's a great example
469
and the belt was a necklace the little pendant on the on the collar correct
470
that was the belt of Orion Wow
471
so cool man all right here we go let's go to
472
some guy two three three four well that's what he put Hey, Neil, Lord Nice, and Dr. Oleshee.
473
Lord?
474
He's Lord.
475
Oh, you didn't know?
476
You didn't know that?
477
No. Yeah.
478
He says, I'm Graham from Marina Del Rey, California.
479
Long -time listener and a first -time caller.
480
I recently learned about a millisecond pulsar whose equator moves at nearly a quarter of the speed of light.
481
Imagine two indestructible astronauts, one standing at or near the pole and one on the equator.
482
What would each see when they look towards each other?
483
Rotational speeds would be much faster at the equator, so how would relativity show up for these, probably quite dizzy, observers?
484
A fun analogy, if Earth were somehow rotated that fast, could familiar landmarks appear in places that seem impossible because of relativistic effects?
485
That's the second question.
486
Thanks so much, and you make astrophysics fun and accessible.
487
The first question is blowing my mind right now.
488
Now, pull an equator, but a pulsar, relativistically, what would they see?
489
This reminds me of that old joke.
490
What's the last thing to go through an insect's mind when it hits your windshield?
491
What?
492
It's ass.
493
That's not bad.
494
Place you on a neutron star, bro, and you're going to be a puddle.
495
She gave us a very good qualifier.
496
Which was? to indestructible astronauts yes okay so they are able to maintain their perspective
497
and their physical integrity while one is at the pole okay
498
and one is at the equator of the pulsar all right
499
so one is definitely spinning faster because it's at the equator
500
if you're rapidly spinning does rapidly spinning create well here's here's the question
501
so this is a calculation one right
502
because relativistic effects show up at extremes of speed and gravitational energy
503
so on a neutron star you have both a rapidly rotating neutron star
504
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.
📺 Mesmo canal
✨ Vídeo recomendado
Sobre esta lição
Você está praticando inglês com "Why Do We Exist? With Hakeem Oluseyi" usando a técnica de Shadowing.
O que é a Técnica de Shadowing?
Shadowing é uma técnica de aprendizado de idiomas com base científica, originalmente desenvolvida para o treinamento de intérpretes profissionais. O método é simples, mas poderoso: você ouve áudio em inglês nativo e repete imediatamente em voz alta — como uma sombra seguindo o falante com 1-2 segundos de atraso. Pesquisas mostram melhora significativa na precisão da pronúncia, entonação, ritmo, sons conectados, compreensão auditiva e fluência na fala.

















