Pratica di Shadowing: The Most Likely Place to Find Aliens - Impara a parlare inglese con i video
Scegli una modalità di pratica
Ogni modalità apre una sala di pratica a schermo intero.
684 frasi
Se le frasi sono troppo corte o troppo lunghe, clicca su Edit per modificarle.
1
Since I was a little kid, I've had a big question.
2
Where are all the aliens?
3
And still, as an adult, I desperately want to be alive when we actually discover extraterrestrial life.
4
And I don't mean all of the conspiracy theories
5
or the well -meaning but totally wrong science fiction or even the math that says, well, there should be someone somewhere.
6
No. I want to know the real science.
7
How are we actually going to discover aliens?
8
Because if we want to be alive when that happens, cosmically, we don't have that much time.
9
So I reached out to one of the most important scientists
10
in the search for intelligent life outside our solar system
11
and who is leading a new effort to find alien life inside our solar system too.
12
In this episode, we're going to show you the real science
13
and tech behind the incredible push happening right now to actually find aliens.
14
Let's go.
15
It's clear that step one to finding real aliens is finding their home.
16
So this is every exoplanet, meaning planets outside our solar system, that we have ever found.
17
Amazing.
18
Isn't this cool?
19
It's just incredible just how many there are, like countless, you'd say.
20
That is Professor Sarah Seeger.
21
She is arguably the most important person in the hunt to find aliens today.
22
She invented some of the key methods that we've already used to understand what's out there.
23
And she's now working on brand new ones that she's going to show us.
24
But what blows my mind about this map is that when I was born, it was blank.
25
Back then, we weren't even sure that there were planets around other stars.
26
And what else is really amazing is this is still nothing.
27
So take us back to 1995 when the first exoplanet was discovered.
28
It was incredibly controversial.
29
It was a big deal.
30
What did you think about that as a graduate student?
31
We were just simply searching for solar system copies.
32
That's like a Jupiter very far from the star.
33
And no one could really believe it.
34
But the reason it was controversial, the signal was incontrovertible.
35
So the signal was definitely real.
36
But whether that signal was from a planet or a different phenomenon on the star itself, that was what was in question.
37
And when you started your PhD and you decided to study exoplanets, you've said that people tried to dissuade you.
38
They tried to say it was a waste of your time.
39
Oh, totally.
40
I mean, there were many people were born to be skeptics and scientists were trained to kind of build on that skepticism.
41
Like you want proof.
42
Many people would say, well, you should talk to my advisor.
43
He'll tell you why.
44
It's not a planet.
45
So there's just this like constant pushback from most people.
46
When we look at something like this, I want to explain to people how we got from nothing to this
47
and then how we're going to get far beyond this, as you said.
48
Okay.
49
Here's our star.
50
What are the different methods for filling in the map already?
51
And then we'll get to the ones that we are going to use next.
52
Well, the most popular method used today is called the transit method.
53
And if this is our star, and this is a planet orbiting that star, for some systems, we're just lucky.
54
The planet happens to orbit the star right along our line of sight, so the planet goes in front of the star,
55
as seen from our telescope.
56
You have to understand that it's all random, so some may be orbiting the star like this with respect to our viewpoint.
57
But for the ones that go in front of the star,
58
as seen from us, the starlight drops by a tiny amount every time the planet goes in front.
59
Yeah.
60
And then it goes back to normal brightness and then drops again.
61
And the biggest drop could be one or two percent, for example.
62
Fascinating.
63
Yeah, the smallest drops are like many decimal places over.
64
Or the star itself could be wobbling.
65
Technically speaking, the planet and star are orbiting the common center of mass.
66
So as the planet goes around, like when the planet's here, the star is wobbled a bit this way.
67
And it just kind of keeps wobbling as the planet's orbiting
68
because it's kind of moving its own orbit around its common center of mass.
69
And we detect in the point of light.
70
We detect the line of sight motion moving towards you, moving away from you.
71
I mean, it's crazy, right?
72
So that's the Doppler method.
73
Yes.
74
And you know, with the Doppler method, astronomers can measure velocities down to like 10 tens of centimeters a second.
75
Think about that for a moment.
76
Incredibly precise.
77
Okay, so we've got transit, we've got Doppler.
78
What's direct imaging?
79
Direct imaging is where we can see the planet directly.
80
So if this were here, and it were big enough and bright enough compared to its star, we could see light directly from this planet.
81
Yes.
82
And that is really hard to do because stars are incredibly bright.
83
In fact, the definition of a star is that it has fusion and is creating its own energy.
84
Planets don't do that.
85
They never create energy.
86
Energy just passes through them or reflects off of them.
87
So they're going to be much, much fainter.
88
And so this would be reflected light?
89
In the best case of direct imaging.
90
It could be.
91
It could be reflected light.
92
It could be absorbed energy that's re -emitted as heat.
93
Got it.
94
Okay, so we've got transit, we've got Doppler, and we've got direct imaging.
95
Am I missing anything else?
96
Well, there are other methods, they're just not as popular right now.
97
There's also motion on the plane of the sky itself, and that is called astrometry.
98
It's measuring very precise positions of stars.
99
And again, all stars are moving, like with respect to us, but they're kind of moving in a straight line.
100
But if there's a planet around it, it kind of is doing like a loop -de -loop,
101
because the planet is causing it to move in three dimensions, the wobbles in three dimensions.
102
And then one more method that honestly never gets airtime, because it's very complicated to describe, but it's incredibly powerful, and it is called gravitational microlensing.
103
When we monitor stars, bright stars, very far away, and in between us and that far away star,
104
an unseen star on planet just happened to drift by perfectly between us and that background star.
105
And from Einstein, we know mass -bend space.
106
Light rays that would normally go off into outer directions, they get bent around to us.
107
And it acts like a lens, hence the word microlens, and magnifies the background star.
108
Sometimes to several times.
109
So enough that we could see some kind of difference or spot that we couldn't see before.
110
All of these methods together are how we've been able, in my lifetime, to fill in over 6 ,000 exoplanets.
111
But, um, what is that?
112
See this weird cone -like shape?
113
Yeah, what is...
114
It's not just so bizarre.
115
Like, let me ask you, do you think there are more planets in that direction?
116
Or is it just that's the direction we have sampled?
117
I have to say, no. I have to say, that has to be the direction that we have just pointed at the telescope.
118
Yeah, it wouldn't make any sense if only planets formed along there.
119
This must be the direction where the Kepler Space Telescope stared for three years.
120
Three plus years, right?
121
I mean, that is insane.
122
So NASA launched the Kepler Space Telescope in 2009.
123
And if you look inside it, you can see exactly this grid shape.
124
It used the transit method to find all of these planets.
125
But that means that if we pointed Kepler or another telescope like it in a different direction,
126
it would find another cone -shaped chunk of these exoplanets.
127
Just think about what's out there.
128
This is just a small, tiny, tiny sample and it's everywhere.
129
Yeah.
130
Okay, so that's Kepler.
131
What's that one?
132
Oh my gosh, this is so cool.
133
This has to be microlensing.
134
Awesome.
135
Because microlensing requires really, really bright stars in the bulge really far away to be the source star.
136
Awesome.
137
So in just the last few decades, we've gone from not knowing if there were planets around other stars to knowing that they are everywhere.
138
But now, once we know a planet is there, the next step is to figure out what it's like.
139
What's its atmosphere like?
140
Who theoretically could be living there depending on what signatures are in that atmosphere?
141
Because at the end of the day, what we want to know is, is anyone out there?
142
You developed a way to do that.
143
And it was totally groundbreaking at the time.
144
And then you were proven right.
145
And now it's being used in so many different ways.
146
Could you explain to me how transit transmission spectroscopy helps us see in the atmospheres of exoplanets?
147
Well, when the planet goes in front of the star, some of the starlight shines through the atmosphere if the planet has an atmosphere.
148
But not all of the light makes it through.
149
Like, imagine shining a flashlight through a fog.
150
Some light makes it through, some doesn't.
151
So we can take a spectrum of the star by itself and then take a spectrum during transit.
152
And the difference in those two essentially tells us what's in the planet atmosphere,
153
because the planet atmosphere is blocking some of the starlight at very specific wavelengths.
154
You wrote a paper that explained how to do this with one of the early exoplanets that we discovered.
155
One of the early stars.
156
The first one.
157
The first one.
158
So this is HD 209458B.
159
And then they actually did it and you were proven right.
160
Correct.
161
I was taken aside and told that they couldn't include me on the team because I was too young.
162
You're like, but here's the method of exactly what you should do.
163
And then when they went out and tried it, It worked.
164
You have to understand just how early the days were.
165
It wasn't like we could now race out and observe a whole bunch of other planets.
166
There literally weren't any.
167
There were maybe two or three transient planets, maybe two.
168
And instead, I just got this giant pushback because at the time I was applying to become a professor.
169
And people would just be, well, it's interesting, but it's a one object, one method success.
170
Meaning that it's cute, but...
171
we're never going to have enough transiting planets. But
172
because I had been working in this race to find transiting planets by just looking at tons of stars at one time,
173
I actually knew how close we were.
174
It's very, very satisfying when nature behaves how you think it should behave.
175
Yeah.
176
You know, if you want to think about it, think about like a ball of gas at chemical equilibrium with the radiation hitting it.
177
And you could then be, well, what are the elements that are there?
178
And then you can kind of go down that list of elements and say, which one is a strong absorber?
179
And so it's just very, I just feel happy that nature agrees.
180
This is crazy to me because I have always heard
181
that our atmosphere is like the skin of an apple on an apple.
182
Like it's just incredible.
183
We think of it as so thick, it's incredibly thin.
184
But you're telling me that we can look at a star that's a tiny point of light.
185
We can see when something changes in that point of light
186
and we can see the light passing through basically the skin part of the apple on its way to us.
187
Yes, we can.
188
However, not for all kinds of planets.
189
Right now, it doesn't work for an Earth -Sun twin.
190
Because our Sun, that backdrop star, is so big and so bright.
191
And our Earth's atmosphere is so tiny.
192
Do none of the methods work for Earth -like planets?
193
Not yet.
194
So that whole map that we just looked at, none of those are really like Earth?
195
None of them are Earth twins.
196
So any headline that we've ever seen about Earth -like planets being discovered has been using a really,
197
really broad, not super scientific definition of what that means.
198
Those ones are either the right size, but they're around much smaller stars, which changes what could be alive there.
199
Or actually way, way bigger than Earth.
200
We can't find an Earth twin yet.
201
We're trying.
202
And we're trying because we think maybe that's the best shot at finding life, or at least life that we can recognize.
203
For finding Earth twins, why is it so hard?
204
It's so hard because planets are so small, so low mass, and so dim compared to the adjacent host star.
205
Our Earth is hundreds of thousands of times less massive than our sun.
206
But our Earth is 10 billion b, billion times fainter than our sun in reflected light.
207
So I don't know if you've come across anything where you have to go to 10
208
or more decimal places to get the job done.
209
Never in my life.
210
It's tough.
211
There's no way to sugarcoat how hard it is to find an Earth twin.
212
So what could we do about that?
213
What we want to do, and this idea has been around for decades, is to go to space above the blurring effects of Earth's atmosphere
214
and to be able to block out the starlight so we can see the planet light directly.
215
Like putting my thumb against the sun?
216
Sure, it could be like putting your thumb against the sun.
217
How do we do that?
218
So it turns out, crazily enough, but in the 1920s, a French optical physicist named Leo,
219
he actually invented a device called the coronagraph about our sun.
220
Have you ever seen a total solar eclipse?
221
Yeah.
222
When you block out the bright part of the sun, you can see the fainter but hot plasma in the corona.
223
So he invented something called a coronagraph where anytime you want, you can block out the sunlight and see the corona.
224
People had that idea.
225
Well, why don't we use this device inside the telescope?
226
We can block out starlight and separate out the planet light.
227
It's tricky.
228
Let's imagine you brought me some banana bread and I say, thank you so much, Cleo.
229
I forgot to mention, I don't eat cinnamon.
230
Meanwhile, you put cinnamon in and there's a lot of flour.
231
There's say 10 billion parts flour and one part cinnamon.
232
And can you please take that cinnamon out?
233
Yes, absolutely.
234
No, no, I think the answer is no. So that's tough.
235
Give me a hundred thousand years.
236
What if I said, I knew you're coming to visit me
237
and that you had been trying to make this banana bread a hundred times better.
238
I'd say I know you're trying to make this great banana bread please bring the cinnamon in a separate dish
239
so if the others want they can put it on top I don't eat cinnamon
240
so now remember the cinnamon is representing the planet light
241
and the banana bread
242
and all the flour is representing the star light there's way more flour than cinnamon now they're separate
243
they never get mixed
244
and it's very easy to keep them separated so we need a technology
245
that separates the planet light so that a telescope can analyze either just
246
that light or just the stars light but not like to do
247
that because the problem is when they're mixed up it's just hard to separate them again
248
and inside the telescope the light bounces around
249
and you have to make the telescope very stable
250
so I love the way where we always keep them separated
251
how do we do it we do it with something called star shade awesome can I go grab
252
that again you can be careful be careful the edges are very sharp
253
I've wanted to play with this ever since I got in this office Starshade is a giant, specially shaped screen.
254
This is a 1 % scale model.
255
So this is huge.
256
Well, imagine if it's 100 times bigger.
257
Awesome.
258
Starshade would have its own spacecraft, and it would formation fly with a space telescope.
259
So they'll both be operating in space, far away from Earth's gravity, because they have to line up extremely precisely.
260
And Starshade would be blocking out a known star to search for planets around that star.
261
The starlight will be blocked and only the planet light will enter the telescope.
262
And why is it shaped like this?
263
Well, that's a great question.
264
You know, if you were to put a circular screen or a square screen in space and block out a star, you would have rings, ripples.
265
Because light can act like a wave.
266
Yeah.
267
And it actually bends around the edges of a giant circular screen.
268
And it will create ripples, just like dropping a pebble in a pond.
269
And those ripples are light ripples, and the light ripples are way brighter than any planet you're looking for.
270
Spitzer invented this special shape in the 1960s.
271
and what he realized was
272
that this shape what it enables is the starlight still acts like a wave
273
and bends around but it interacts with itself
274
so cleo do you see this black thing behind me do you want to guess what it is i think
275
that should be a full size version of just this little piece
276
it is it is just a single petal just that correct cool
277
and it's it gives you a sense of just how giant
278
this this screen could be what's the status of it right now like would starshade be something
279
that could see starshade you know it was invented in the 1960s
280
and every decade it has been revived and shelved
281
and we had a real heyday since about 2013
282
when starshade has been moving forward very rapidly we had directed funding
283
we solved a lot of hard problems we have large radio deployables in space
284
that we have heritage for to build how starshade will still and deploy but unfortunately right now, the Starshade funding is on hold.
285
And so we're trying to keep Starshade alive.
286
Right now, NASA has plans to build the Habitable Worlds Observatory using the coronagraph on the inside.
287
And that's the one where it's possible, but it's hard to separate out the cinnamon.
288
Very hard to separate the cinnamon.
289
And the coronagraph still has a ways to go for lab demo.
290
Starshade has been demonstrated to work to the contrast needed.
291
And big picture to remind people of why,
292
if this show is all about participating in those features and caring about them to try and make them happen,
293
the reason to care about starshade is if we can separate out the star's light, we have a chance at detecting more
294
Earth -like planets.
295
So let's assume that some of these methods happen and we are looking at Earth -like planets around sun -like stars.
296
What are we looking for?
297
That's a great question.
298
And to be frankly as honest as possible, we are still working on that.
299
Awesome.
300
What are the options?
301
Well, one option is the Earth twin.
302
Literally carbon dioxide and...
303
Yeah, tiny bit of carbon dioxide, a lot of water vapor on Earth.
304
Oxygen is made by plants and photosynthetic bacteria.
305
It's highly reactive.
306
It wouldn't be in our atmosphere unless it's continually produced.
307
That's life as we know it on Earth.
308
But alien planets could work completely differently.
309
So we're also trying to get better at understanding what life could be like that's really different from us.
310
Life as we don't know it.
311
Let's imagine for a moment there's a Clio and there's a Professor Seeger on an alien world and they don't have oxygen.
312
And they're talking about the same conversation and they're saying, what kind of planet do you think could support life?
313
They might even say, well, we found this planet has a lot of oxygen.
314
It's terrible.
315
It has so much oxygen.
316
How could anyone live there?
317
It would have large regional fires at any time.
318
We'll find a bunch of things.
319
We'll be like, wow, this has oxygen, or this has this gas, or this has another gas.
320
But we won't be sure because there will always be the opposing view.
321
A lot of people have their favorites.
322
One of my favorite gases is phosphine.
323
It has a unique spectral signature
324
that doesn't overlap with any other major gases like carbon dioxide
325
or methane or anything on earth it shouldn't exist because it takes energy to make it.
326
Yet on earth it does exist, but it's only associated with life.
327
Okay, so those could be signs of microbes.
328
But what about intelligent life?
329
When we search for intelligent life, are we searching for different things?
330
Are we searching for the same biosignatures?
331
And when we say intelligent, what do we actually mean?
332
Like Oh my God, intelligent life.
333
This is incredible.
334
Yeah.
335
Like imagine if you found a dog on an alien planet.
336
This is my dog, Thor.
337
He's a 10 pound mini Australian Shepherd.
338
He's a big fan of Hill's Pet Nutrition and he's 12 years old, but I think he still looks like a puppy.
339
Thor has been my guy since long before I started huge.
340
Oh, and he's been with me every step of making this show.
341
But this show also means that I need to leave him sometimes.
342
The longest was a trip to Antarctica for three weeks.
343
I feel so guilty when I'm gone.
344
Like, he's 12 years old.
345
I want every moment with him.
346
And I want to try to give him the best of everything that I possibly can.
347
The big one is his food.
348
Thor really likes this one from Hills, which is why I'm so excited to partner with them.
349
What he likes is the taste.
350
What I like is the science.
351
Because Thor's gut is home to trillions of microbes that help digest his food and support his immune system.
352
And prebiotic fiber is food for the good ones.
353
So Hills uses two kinds that work in different parts of his gut.
354
So when those bacteria break the fiber down, they make helpful compounds that support his organs like his heart and his kidneys.
355
And every time Thor turns food into energy, he makes free radicals, which are these unstable molecules that can damage his cells.
356
Antioxidants are the cleanup crew.
357
Vitamins C and E help neutralize those free radicals before they do harm.
358
The older Thor gets, the more free radicals his body makes, so the antioxidants in his food matter more.
359
No food is magic.
360
But giving his body the right building blocks backed by real research, that's something I can do.
361
I want the science to help him live longer so that I can have more time to love him.
362
Discover the science behind a long, healthy life for your pet at hillspet .com slash science does more.
363
Okay, back to intelligent aliens.
364
Are we talking about any kind of sentience?
365
Are we talking about little green men?
366
Like, how does the field think about the range from microbial life to intelligent extraterrestrial civilizations?
367
When it comes to gases, of course, we humans give off gas.
368
We're breathing out carbon dioxide.
369
We have cows giving off methane.
370
There are gases that intelligent life does produce, but we can't separate out with basic gases, whether it's microbes or intelligent life.
371
And when it does come to gases, though, there is a category called technosignature gases.
372
We produce some complicated gases, like we produce chlorofluorocarbons.
373
And there are some gases, it's going to sound a bit obscure, Sf6, sulfur tetrafluoride, and NF3.
374
We have some gases that are only used industrially that life never makes.
375
And then people love techno signatures in general, like purposeful radio communications or crazy large structures aliens may have built.
376
So there's sort of the full range out there of what people think about.
377
But it's hard, really hard.
378
Like from afar, aliens with telescopes more sophisticated than ours,
379
like just more like what we're trying to build like starshade they would see oxygen they might infer those oceans
380
and continents would they see city lights
381
or pollution no would they see the great wall of china no
382
so it's like a whole other level to find techno signatures yeah
383
so we're not going to see dogs
384
we're not going to see humanoids unfortunately right now that's way beyond what we can do.
385
I have a question from someone who I have previously interviewed on this show, Project Hail Mary author Andy Weir.
386
He wrote a story about one of my favorite aliens of all time.
387
His name is Rocky.
388
Hi, Grace.
389
He asks, Earth converted sunlight into fossil fuels for millions of years.
390
Would that energy discrepancy be detectable comparing a planet's energy radiation to its presumed energy absorption of the star?
391
Or would it be lost in the noise of normal variants?
392
I think he's asking, could some alien civilization very far away see
393
that we are giving off more energy than we should be currently absorbing from the sun, therefore we are here?
394
Well, that's a good question.
395
Right now, we can't detect that.
396
You have to think about it.
397
We can, it sounds like grand and incredible, all the things we can do.
398
But if you wanted to really analyze that, like under a microscope, so to speak, we can barely do anything.
399
So, you know, how our planet's heating up and we have forest fires and we have climate change, we couldn't detect that from afar.
400
Like, there's no way they could, if they're lucky, they could see we have carbon dioxide at all,
401
let alone that it's going up parts per million every year.
402
Thinking about that map and thinking about now we're in a world where we've filled it even more in,
403
where do you think we're most likely to find intelligent alien life?
404
First we ask, Are there exoplanets?
405
Check.
406
Are there rocky exoplanets in the habitable zone where they might host life?
407
Check.
408
Now we're on to, is there going to be water vapor or liquids where life could exist?
409
We're still working on that.
410
It sounds like you're outlining popularly the Drake equation.
411
Those are the variables in what I understand to be the Drake equation, but I also know you have the Seeger equation.
412
Yes, yes.
413
And I, by the way, what are the differences?
414
Drake's equation is broken down into terms.
415
The search for extraterrestrial intelligence by way of radio communication.
416
How many stars are being born each year?
417
What fraction of them have planets in the habitable zone?
418
What fraction have intelligent life?
419
How long do civilizations last?
420
And I took the Drake equation and recast it for the search for not intelligent life, but any life by way of biosignature gases.
421
And I did this considering a few different cases, but one case was what we talked about,
422
transmission spectra and I said if you have a certain number of stars here are the factors that are important.
423
We have to get really lucky in the time boxed period of when they're alive.
424
Yeah but one concept I do love I've really glommed on to it's a really scary concept.
425
Okay.
426
Do you want to hear it?
427
Yes I'm ready.
428
Well AI is starting to pervade our life.
429
Yes.
430
And we only have a glimpse of where it's heading.
431
Yes.
432
And there's a big fear rightly so that a few generations from now
433
or sooner or sooner right it could be 10 years could be a generation or two
434
AI is our boss and it kind of has taken over.
435
We also in parallel have data farms being considered for space.
436
Have you heard of those?
437
Yeah.
438
This would ruin our night sky.
439
So it's very depressing for astronomy.
440
But imagine for a moment that you have AI in space.
441
So they're getting solar energy and they're giving off heat to space, but they also have the ability to reproduce
442
because on earth are a lot of big startups with big money about robotic self -driven AI.
443
Have you heard of that self -driven labs rather
444
so now let's put all
445
that together the ice taking over it's in space
446
it can self -reproduce it's getting energy from the sun it has intelligence it wants more energy
447
where's it going to go the sun okay it'll orbit our sun maybe
448
that's what we should be looking for yeah intelligent ai yeah maybe it's not just our sun
449
and i can't take claim for for this idea
450
and maybe now it's moving to a local black hole where there's more energy maybe
451
now it's moving to our galactic black hole.
452
I mean, there's a lot of ideas out there, but if you want to think about how long we've been here,
453
really just the blink of an eye and the sort of exponential we're on for AI, you know, maybe that's what we should be looking for.
454
What are your, I want to know what your thoughts are.
455
I just outlined a scenario.
456
I didn't say whether I totally buy into it, but what are your thoughts?
457
I am less scared of that than I thought I was going to be.
458
I would not assume in either direction about the way that AI is either constrained here on earth or treats us.
459
So within that hypothetical, there are still a lot of options where humanity is happy or supported by the AI.
460
And yes, the AI is self -replicating and going toward the black holes and maybe on behalf of humanity, looking for other contact with other AIs.
461
I absolutely buy that we've only been around for a short period of time.
462
We're trying to find civilizations that are either just below us
463
or way above us because we assume
464
that we've only started being able to detect or being able to emit ways that they could detect fairly recently.
465
So we need to find somebody older than us, basically.
466
Right, right.
467
And if that's the case, then it seems to me plausible that the first thing
468
that we would encounter are their forms of technology that they have created somehow.
469
Maybe.
470
I buy that.
471
What are your thoughts on it?
472
Well, I think we should definitely add it to the list of something we're looking for.
473
Yeah.
474
Because that could be a sign of intelligent life.
475
And you know, do you know what I'm saying?
476
Like they might not send us a radio signal.
477
Maybe they don't want to or can't.
478
But I easily see it as not too far of a leap from where we're heading.
479
We've only been talking about exoplanets so far.
480
Right, right.
481
It seems to me that it's still possible to find microbial life somewhere in our solar system.
482
Why not?
483
You're working on a way to do this.
484
I definitely am.
485
But not on the planet that most people think.
486
People know about Mars.
487
Venus sometimes gets called Earth's evil twin.
488
How did it get that nickname?
489
Well, Venus itself is about Earth's size and about Earth's mass.
490
And many people think it was born like
491
Earth with water oceans, maybe it had continents and like a nice atmosphere.
492
But Venus is just that much closer to the sun.
493
And it had volcanoes and it's hotter and it had a greenhouse atmosphere and eventually it just got too hot.
494
Venus went through a tipping point and got too hot for water to be sustainable.
495
So then that carbon dioxide that supposedly was dissolved in the ocean came back to the atmosphere and made it even hotter.
496
And eventually it's just way too hot on the surface anyway for any kind of life we could imagine.
497
In the 70s and early 80s, over a dozen former
498
Soviet Union missions went to Venus.
499
NASA sent Pioneer Venus.
500
So where could there possibly be life on Venus?
501
Well, not on the surface, which is too hot.
502
But just like on Earth, when you go in the airplane or you hike up a mountain, it gets colder and colder.
503
And that also happens on Venus, on most planets actually.
504
On Venus, about 50, 50 kilometers above the surface, it's the right temperature for life.
505
So there could be life in the clouds of the Earth.
506
There could be life in the clouds.
507
And this by no means was my idea.
508
Carl Sagan, we think, was the first one to propose this.
509
I remember.
510
It is just possible that the hot region exists at a high altitude in the ionosphere of Venus.
511
The surface temperature could then be almost
512
Earth -like, and life as we know it could exist there.
513
So how are we going to find out?
514
I know about missions to Mars.
515
You're leading a mission called the Morningstar mission.
516
Yes, I can tell you about that.
517
So we want to go to Venus.
518
It's still too crazy.
519
It's too taboo for NASA and large government agencies.
520
So we're trying to do a series of missions.
521
Each builds on the one before that are largely privately funded.
522
And we call ourselves the Morningstar missions to Venus.
523
We're also trying to get this message across of like a new dawn is rising for space missions.
524
Instead of waiting over four decades to go back to the atmosphere of Venus or a planet, let's shift gears.
525
Let's complement the NASA missions and have small, very, very focused missions that just have like a single goal.
526
So the goal would be of the Morningstar missions?
527
Well, the eventual goal, eventually, in time, is a sample return.
528
Awesome.
529
is that the pieces that we should talk about yes why don't we talk about
530
that yeah let's bring that over okay this is all right thank you
531
so this is a 3d printed model of the actual size
532
of morning star's first mission to venus called the rocket lab mission to venus it's beautiful
533
and this first mission is like a small cheap mission
534
so this is the entry capsule but it's also the probe shell
535
so normally the entry capsule like opens up but this is just going to be it it's just this
536
it'll just get dropped off it'll slow down based on its own drag
537
and it will have five minutes in the clouds to perform its job
538
and it'll keep going and slow down
539
and eventually it will crash land on the surface will it send back enough data for us to understand well
540
it has to
541
so it's kind of like all like a puzzle
542
you have to make sure it's all tied together properly would you like to open it yeah i didn't know
543
that was an option yeah it's right here just put your hand like in the and see what's inside.
544
And this is a 3D printed model.
545
Cool!
546
You have the best choice.
547
Would you like to take it out?
548
Yes.
549
And this, you know, kind of looks like a little alien.
550
Doesn't it look kind of like an R2 -D2?
551
Yeah, look.
552
Yep.
553
It's not.
554
Isn't it cute?
555
Inside would be like the computer, the radio, the batteries.
556
You know, inside would be like the mission itself.
557
So what we're going to do is we have a laser that we're going to be shining through this window.
558
And not shown on here, but one of these will have a hole one of these side things will have a hole.
559
So the laser will shine out and it will hit the cloud particles.
560
And so from the information that it sends back, we'll find out more about what's hidden in those clouds.
561
This is part one of the Morningstar missions.
562
Part one.
563
I think in latter parts, you're going to use this.
564
What is this?
565
Okay, I want you to know that when you build things for space, there's like 100 steps.
566
Yeah.
567
So this would be about step, say, three out of 100.
568
Okay.
569
Maybe step five.
570
Okay.
571
Well, what we'd like to do eventually is capture the cloud particles of Venus
572
and have like literally liquid to analyze in the atmosphere.
573
And so the first step in doing that, we call it our cloud catcher.
574
You know how when you're in a foggy environment and the fog collects on your jacket?
575
It's like that.
576
Only there are these wire mesh layers.
577
But there's still a big problem with these clouds.
578
The clouds aren't made of water.
579
That's the problem.
580
What are they made of?
581
Acid.
582
Concentrated sulfuric acid.
583
Can life survive in concentrated sulfuric acid our life cannot survive it just cannot there's no way it can
584
so one thing my lab does is we study molecules in concentrated sulfuric acid
585
and so while our life can never survive our dna is completely unstable it turns out
586
that some molecules are stable like our amino acids stable in
587
sulfuric acid huh our nucleic acid bases stable small peptides stable lipids stable we put a lot of molecules in sulfuric acid.
588
We study other non -water solvents, but it's actually pretty remarkable that you can just do this in the lab and find out amazing things.
589
We're trying to find a DNA -like molecule that's stable and concentrated sulfuric acid, and we have a big milestone in that direction already.
590
Can you tell us what the milestone is?
591
Sure.
592
We have found that a molecule like DNA, it's not DNA itself.
593
Oddly, it's called PNA, peptide nucleic acid.
594
It's different from DNA.
595
It has the same latter part, but a different backbone.
596
And we have demonstrated that up to about 50 degrees Celsius, it's stable in like pure concentrated sulfuric acid.
597
So this would tell me on the clouds of Venus, for example, that there could be built using similar building blocks,
598
building different things, not DNA, but other things.
599
That's right.
600
Life made out of those things there.
601
Right.
602
Cool.
603
As proven by it surviving in these jars.
604
One of the things that has always struck me about this is people are just
605
so interested in the topic of finding aliens.
606
You know, the Pentagon releases UAP information.
607
And I went to Antarctica recently,
608
and you would be surprised at the number of people who genuinely told me that they thought I'd find aliens there.
609
And it feels like this subject is either taken over by theories about unproven encounters
610
or well -meaning science fiction that represents a very different world than the one
611
that we're living in and sometimes gives misimpressions about how this might happen.
612
And then there's you and scientists like you that are trying to say, here are the actual ways in which we would realistically find aliens.
613
Here's the human work that needs to go into that.
614
If you're talking to millions of people, which I hope we are on this episode, what would you encourage them to direct their attention to?
615
There's so many things scientifically.
616
Two things that are my personal favorites.
617
One is the upcoming
618
Nancy Grace Roman Space Telescope launch.
619
Because out of all those planets out there, we still don't know how common or rare our solar system is.
620
It's very hard to find.
621
We know it's rare.
622
because we found all the other systems, but we don't know how common it is, and the new telescope should answer that.
623
And by that you mean the particular kind of arrangement of planets we have?
624
Yes.
625
Got it.
626
Yeah.
627
And the other thing that I've been really intrigued with lately too is, we're not kidding.
628
The ingredients for life are found everywhere.
629
So this isn't about aliens, but honestly, the more chance for aliens to be out there is
630
if there are more chances for life to be out there.
631
All the test data, all the Kepler data, all the data made by the James Webb Space Telescope, because it's all taxpayer funded,
632
all the data is public.
633
And it's not only public, but there are different levels of data product.
634
You could be brave and like take the almost raw data, or you could take the light curve that's already made and look for unusual things.
635
You can get your hands dirty as well as learning more domain knowledge along the way.
636
In preparation for this, I read your amazing book.
637
Thank you.
638
It's called The Smallest Lights in the Universe.
639
And if you don't mind, I'm going to ask you a personal question about it.
640
We can skip right over it if you're comfortable.
641
The title of this book, I think, refers to the fact that you're a scientist who is looking at these tiny little lights made by planets.
642
And they're the smallest.
643
They're so faint.
644
And also you talk about how your husband died when both of you were very young and you had young kids.
645
And you're looking for hope in small things.
646
You're dealing with grief.
647
Could you tell me about what your personal motivation was to continue this work
648
and how you think this has personally played out for you?
649
Well, I'm really pleased you understood the title because it does have the dual meaning of personal,
650
where when you're really down in the bottom of despair, you have to hold on to those small slights of hope.
651
And in the other sense, they are the small slights of Earth.
652
They're 10 billion times stancher than the suns.
653
But what happened was this, and I'm going to try to say it for you.
654
You know, the human mind is an amazing thing we don't understand why we have consciousness
655
we don't understand why we feel the way we do
656
but i'll tell you one thing
657
when my first husband mike died it was an incredible journey you can die well
658
and it's a really special journey it's very very important as a culture
659
that we can be open minded to that
660
and after he died he had the perfect death i just want you to know yeah
661
and i was by his side and everything and after that uh life was meaningless all of a sudden
662
because that's like if you have anything in your life that's
663
so momentous what's the point of living yeah
664
and i really held on to those smallest lights
665
and decided my life was going to have purpose and
666
that purpose comes on many axes one axis is it is my dream to find another earth
667
and that is that is my purpose
668
and after he died i had a wonderful few years of discovery but it's not just finding another earth, it's finding life out there.
669
It's finding ways to get job done.
670
And it's inspiring the next generation and giving everyone permission.
671
I don't want you to have a catastrophe to like get on your big thing.
672
But the point of the story is also that we can do great things.
673
And we do have resilience.
674
And there is a path forward if you can strategize
675
and get on that path and have help from your teachers
676
and friends and hopefully parents or like others to help you get there, we all have a way to get the job done.
677
Thank you for the job that you're doing.
678
I think a lot of people are like me who feel personally inspired by you
679
and know about the work that you're doing and feel that from PhD onward,
680
you have struck this very risk -taking path on behalf of all of us that has a lot of human benefits, right?
681
I think you personally are inspiring.
682
and also I think there are lots of people who maybe until now did not know about this work
683
and now can see how you've been benefiting them all along
684
so thank you so much for your time and for your work and thank you Cleo really it's been a pleasure
Scarica l'app
Tutto ciò che serve per parlare fluentemente
Pronuncia con IAVoto per ogni frase
Pratica IPAPadroneggia ogni suono
VocabolarioCostruisci il tuo lessico
Gioco di vocabolarioImpara giocando
Stesso Canale
C11
Editing Your DNA, with Nobel Prize Winner Dr. Jennifer Doudna
Daily ConversationUniversity Students
B140
Antarctica Is Bigger Than You Think
American AccentDaily ConversationWorking Adults
B22
Formula 1, Explained for Rookies
American AccentBusiness EnglishUniversity StudentsWorking Adults
B25
How Big Is The Biggest Black Hole?
American AccentUniversity Students
C12
What If I Fell Into A Black Hole?
American AccentIELTS PrepTOEFL PrepUniversity Students
B22
What If The Earth Was Flat?
American AccentUniversity Students
B23
The Shoe That Broke Running
American AccentBusiness EnglishDaily ConversationUniversity Students
C12
I Wrote a NEW Sci-Fi with Project Hail Mary Author Andy Weir
American AccentBusiness EnglishUniversity StudentsWorking Adults
B22
Formula 1 Cars, Explained with Max Verstappen
American AccentBusiness EnglishUniversity StudentsWorking Adults
B21
Would You Use An Artificial Womb? (I Would)
American AccentIELTS PrepTOEFL PrepUniversity Students
B28
Humanity’s Real Plan to Stop This Asteroid (Feat. Mark Rober)
American AccentIELTS PrepTOEFL PrepUniversity Students
C14
Why Gravity Is A Lie, explained in Zero G
American AccentIELTS PrepTOEFL PrepUniversity Students
B22
The New Hunt for the Colossal Squid
American AccentIELTS PrepTOEFL PrepUniversity Students
B22
The Ocean Is Deeper Than You Think. We Need Better Maps.
American AccentIELTS PrepTOEFL PrepUniversity Students
B26
Something’s Happening to the Ozone Hole
American AccentIELTS PrepTOEFL PrepUniversity Students
B231
The Future Mark Zuckerberg Is Trying To Build
American AccentBusiness EnglishDaily ConversationUniversity Students
B2The Big Lie About Nuclear Waste
Daily ConversationUniversity StudentsWorking Adults
B2How Did Dinosaurs Actually Go Extinct?
Daily ConversationWorking Adults
B2The Sun Is Weirder Than You Think
American AccentDaily ConversationUniversity StudentsWorking Adults
C1How Will The Universe Die?
American AccentUniversity StudentsWorking Adults
FOR YOU
Video consigliato
C12
47 frasi
We Found Galaxies Too Old for the Universe
Daily ConversationUniversity StudentsWorking Adults
C11
23 frasi
What is a Seeker?
Daily ConversationUniversity StudentsWorking Adults
C12
48 frasi
Four Places We Might Find Aliens
Daily ConversationUniversity Students
C13
742 frasi
The REAL reason China built so much
Daily ConversationUniversity StudentsWorking Adults
C12
560 frasi
The Most Dangerous Woman in Science Says We Got the Dinosaur Extinction Totally Wrong
Daily ConversationUniversity StudentsWorking Adults
C14
204 frasi
The Insane Biology of: The Octopus
Daily ConversationUniversity StudentsWorking Adults
C12
175 frasi
What NASA Found on Io
Daily ConversationUniversity StudentsWorking Adults
C11
402 frasi
Before We Became the Last Humans:The Lost Species That Once Shared Our World|Prehistoric Documentary
Daily ConversationUniversity StudentsWorking Adults
C185
66 frasi
What science can’t answer, according to physicist Jim Al-Khalili | Big Think
Daily ConversationUniversity StudentsWorking Adults
B218
41 frasi
Unit 6: Living on Mars
Daily ConversationUniversity StudentsWorking Adults
C12
224 frasi
20% Speed of Light!! NEW Light Engine is INSANE!
Daily ConversationUniversity StudentsWorking Adults
C14
101 frasi
Life on Tristan da Cunha – the World's Most Remote Inhabited Island
Travel EnglishTeensDaily Conversation
Vocabolario e note di pronuncia per questa lezione
Questa lezione di conversazione si basa sul video “The Most Likely Place to Find Aliens”. Questo video contiene 41 frasi e 7511 parole da ripetere con lo shadowing. Il parlato dura 38:51. Chi parla va veloce, circa 193 parole al minuto: aspettati suoni legati e ridotti. Il 84% delle parole rientra nelle 3.000 più comuni dell’inglese; conviene studiare le altre prima di iniziare. 90 delle sue 41 frasi sono domande: un buon esercizio per l’intonazione interrogativa e le risposte brevi.
Vocaboli chiave di questo video
15 parole del video che vale la pena imparare, con pronuncia e significato:
| Parola | Pronuncia | Significato |
|---|---|---|
| atmosphere sostantivo | /ˈætməsˌfɪɹ/ | atmosfera |
| intelligent aggettivo | /ɪnˈtɛlɪd͡ʒənt/ | intelligente |
| telescope sostantivo | /ˈtɛl.əˌskoʊp/ | telescopio, cannocchiale |
| cloud sostantivo | /ˈklaʊ̯d/ | nuvola, nube |
| acid sostantivo | /ˈæsɪd/ | acido |
| cinnamon sostantivo | /ˈsɪnəmən/ | cannella |
| stable sostantivo | /ˈsteɪ.bəl/ | stalla, scuderia |
| transit sostantivo | /ˈtɹæn.zɪt/ | transizione, traversata |
| twin sostantivo | /twɪn/ | gemello, gemella |
| orbit sostantivo | /ˈɔɹ.bɪt/ | orbita |
| oxygen sostantivo | /ˈɑksɪd͡ʒən/ | ossigeno |
| detect verbo | /dɪˈtɛkt/ | individuare, rilevare |
| dioxide sostantivo | /daɪˈɑksaɪd/ | diossido, biossido |
| molecule sostantivo | /ˈmɑ.lɪ.kjul/ | molecola |
| incredibly avverbio | /ɪŋˈkɹɛdɪbli/ | incredibilmente |
I phrasal verb che sentirai
| Parola | Pronuncia | Significato |
|---|---|---|
| give off verbo | /ɡɪv ɒf/ | emettere |
| find out verbo | scoprire | |
| take over verbo | usurpare | |
| pass through verbo | trapassare | |
| send back verbo | rispedire | |
| slow down verbo | rallentare, decelerare | |
| turn out verbo | risultare | |
| come across verbo | dare l'impressione, avere l'aria |
Frasi da ripetere
Frasi brevi e complete del video che puoi riutilizzare nella conversazione di tutti i giorni:
- How are we actually going to discover aliens?
- Am I missing anything else?
- How do we do that?
- Have you ever seen a total solar eclipse?
- Why don't we talk about that?
La grammatica di questo video
Le strutture che chi parla usa di più, con le parole esatte del video:
| Struttura | Nel video |
|---|---|
| Present perfect continuous have/has been + -ing — un’azione iniziata prima e ancora in corso | has been using · has been moving · We've only been talking |
| Present perfect have/has + participio passato — un’azione passata che conta ancora adesso | I've had · have ever found · you've said |
| Forma passiva be + participio passato — conta ciò che accade, non chi lo fa | was born · was discovered · were born |
| Frasi relative who / which + frase — un’informazione in più su una persona o una cosa | Hills, which is · radicals, which are · someone who I |
Pronuncia a cui fare attenzione
Chi parla usa 151 contrazioni e forme ridotte, come we're, don't, you're. Pronunciale nella forma breve, così come le senti.
- I suoni “th”: thumb /ˈθʌm/, methane /ˈmiːθeɪn/, thin /ˈθɪn/, thick /θɪk/, breathe /bɹiːð/
- I suoni “sh” e “zh”: equation /ɪˈkweɪ.ʒən/, shine /ʃaɪn/, civilization /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/, fiction /ˈfɪkʃən/, transmission /tɹænsˈmɪʃən/
- Parole lunghe — attenzione all’accento: intelligent /ɪnˈtɛlɪd͡ʒənt/, incredibly /ɪŋˈkɹɛdɪbli/, civilization /ˌsɪv.ɪ.laɪˈzeɪ.ʃən/, complicated /ˈkɑm.plɪˌkeɪ.tɪd/, humanity /hjuˈmænɪti/
I suoni difficili per chi parla italiano:
- /h/ — va soffiata, non è muta: behalf /bɪˈhæf/, humanity /hjuˈmænɪti/, harm /hɑːm/, helpful /ˈhɛlp.fl̩/, hence /ˈhɛns/
- Consonante finale — senza aggiungere una vocale dopo: intelligent /ɪnˈtɛlɪd͡ʒənt/, telescope /ˈtɛl.əˌskoʊp/, cloud /ˈklaʊ̯d/, acid /ˈæsɪd/, transit /ˈtɹæn.zɪt/
- /æ/ — più aperta della “e”: atmosphere /ˈætməsˌfɪɹ/, acid /ˈæsɪd/, transit /ˈtɹæn.zɪt/, banana /bəˈnænə/, radical /ˈɹædɪkəl/
Come esercitarsi con questo video
- Ascolta tutto il video una volta senza parlare e annota le parole che non conosci.
- Inizia a velocità 0,75×, fai shadowing frase per frase e torna alla velocità normale quando diventa facile.
- Registrati e confronta con l’originale, facendo attenzione a parole come atmosphere, intelligent, telescope.
Cos'è la tecnica dello Shadowing?
Shadowing è una tecnica di apprendimento delle lingue supportata da studi scientifici, originariamente sviluppata per la formazione dei traduttori professionisti e resa popolare dal poliglotta Dr. Alexander Arguelles. Il metodo è semplice ma potente: ascolti un audio in inglese di madrelingua e lo ripeti immediatamente ad alta voce — come un'ombra che segue il parlante con un ritardo di solo 1–2 secondi. A differenza dell'ascolto passivo o degli esercizi di grammatica, lo shadowing costringe il tuo cervello e i muscoli della bocca a elaborare e riprodurre simultaneamente i modelli di discorso reale. La ricerca dimostra che migliora significativamente la precisione della pronuncia, l'intonazione, il ritmo, il discorso connesso, la comprensione dell'ascolto e la fluidità del parlato — rendendolo uno dei metodi più efficaci per la preparazione alla prova di speaking dell'IELTS e per la comunicazione reale in inglese.