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Dave Brain: What a planet needs to sustain life
Dejv Brejn (Dave Brain): Šta je potrebno planeti da bi održavala život
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Readability: 4.1
1,867,290 views
"Venera je suviše vrela, Mars je suviše hladan, a Zemlja je potaman", kaže planetarni naučnik Dejv Brejn. Međutim zašto? U ovom prijatnom, duhovitom govoru, Brejn istražuje očaravajuću nauku u pozadini toga šta je potrebno planeti da udomi život - i zašto je čovečanstvo možda baš na pravom mestu u pravom trenutku, kada se radi o listi planeta koje održavaju život.
Dave Brain - Planetary scientist
Dave Brain studies the plasma environments and atmospheres of unmagnetized planets. Full bio
Dave Brain studies the plasma environments and atmospheres of unmagnetized planets. Full bio
Double-click the English transcript below to play the video.
00:12
I'm really glad to be here.
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Baš mi je drago što sam ovde.
00:15
I'm glad you're here,
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Drago mi je što ste vi ovde,
00:16
because that would be a little weird.
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inače bi bilo malčice čudno.
00:19
I'm glad we're all here.
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Drago mi je što smo svi ovde.
00:22
And by "here," I don't mean here.
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A pod "ovde", ne mislim na ovde.
00:26
Or here.
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Ili ovde.
00:28
But here.
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Već ovde.
00:29
I mean Earth.
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Mislim na Zemlju.
00:31
And by "we," I don't mean
those of us in this auditorium,
those of us in this auditorium,
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I pod "mi" ne mislim
na nas u auditorijumu,
na nas u auditorijumu,
00:35
but life,
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već na život,
00:37
all life on Earth --
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sav život na Zemlji -
00:38
(Laughter)
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(Smeh)
00:44
from complex to single-celled,
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od složenog do jednoćelijskog,
00:46
from mold to mushrooms
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od buđi preko pečuraka
00:48
to flying bears.
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do letećih medveda.
00:50
(Laughter)
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(Smeh)
00:53
The interesting thing is,
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Zanimljivo
00:55
Earth is the only place
we know of that has life --
we know of that has life --
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da je Zemlja jedino poznato mesto
na kom ima života -
na kom ima života -
00:58
8.7 million species.
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8,7 miliona vrsta.
01:00
We've looked other places,
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Tražili smo druga mesta,
možda ne onoliko
koliko smo trebali ili mogli,
koliko smo trebali ili mogli,
01:01
maybe not as hard
as we should or we could,
as we should or we could,
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01:04
but we've looked and haven't found any;
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ali tražili smo i nismo našli bilo šta;
01:06
Earth is the only place
we know of with life.
we know of with life.
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Zemlja je jedino
nama poznato mesto sa životom.
nama poznato mesto sa životom.
01:09
Is Earth special?
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Da li je Zemlja posebna?
01:11
This is a question I've wanted
to know the answer to
to know the answer to
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Odgovor na ovo pitanje
sam želeo da znam
sam želeo da znam
01:14
since I was a small child,
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od svog ranog detinjstva,
01:15
and I suspect 80 percent
of this auditorium
of this auditorium
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i pretpostavljam da 80%
ovog auditorijuma
ovog auditorijuma
01:17
has thought the same thing
and also wanted to know the answer.
and also wanted to know the answer.
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je pomislilo isto to
i takođe je želelo da zna odgovor.
i takođe je želelo da zna odgovor.
01:20
To understand whether
there are any planets --
there are any planets --
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Da bismo razumeli
ima li još nekih planeta -
ima li još nekih planeta -
01:23
out there in our solar system or beyond --
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u našem solarnom sistemu i dalje -
01:25
that can support life,
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koje mogu da održavaju život,
01:26
the first step is to understand
what life here requires.
what life here requires.
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prvi korak je u razumevanju
šta je neophodno za život.
šta je neophodno za život.
01:30
It turns out, of all of those
8.7 million species,
8.7 million species,
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Ispostavilo se da su za život
svih 8,7 miliona vrsta
svih 8,7 miliona vrsta
01:34
life only needs three things.
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potrebne tri stvari.
01:37
On one side, all life
on Earth needs energy.
on Earth needs energy.
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S jedne strane, svem životu na Zemlji
je potrebna energija.
je potrebna energija.
01:39
Complex life like us derives
our energy from the sun,
our energy from the sun,
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Složeni život poput našeg
dobija energiju od sunca,
dobija energiju od sunca,
01:43
but life deep underground
can get its energy
can get its energy
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ali život duboko pod zemljom
dobija energiju
dobija energiju
01:45
from things like chemical reactions.
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od, recimo, hemijskih reakcija.
01:47
There are a number
of different energy sources
of different energy sources
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Ima više različitih izvora energije
01:49
available on all planets.
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dostupnih na svim planetama.
01:51
On the other side,
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S druge strane,
01:52
all life needs food or nourishment.
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svem životu je potrebna hrana ili ishrana.
01:55
And this seems like a tall order,
especially if you want a succulent tomato.
especially if you want a succulent tomato.
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A ovo se čini kao težak zadatak,
naročito ako želite sočan paradajz.
naročito ako želite sočan paradajz.
02:00
(Laughter)
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(Smeh)
02:01
However, all life on Earth
derives its nourishment
derives its nourishment
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Međutim, sav život na Zemlji dobija hranu
02:05
from only six chemical elements,
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iz svega šest hemijskih elemenata,
02:07
and these elements can be found
on any planetary body
on any planetary body
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a ovi elementi su prisutni
na bilo kojoj planeti
na bilo kojoj planeti
02:10
in our solar system.
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u našem solarnom sistemu.
02:12
So that leaves the thing
in the middle as the tall pole,
in the middle as the tall pole,
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Te je zbog toga ovo u sredini
težak zadatak,
težak zadatak,
02:15
the thing that's hardest to achieve.
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nešto što je najteže postići.
02:17
Not moose, but water.
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Ne los, već voda.
02:19
(Laughter)
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(Smeh)
02:23
Although moose would be pretty cool.
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Iako bi los bio baš super.
02:25
(Laughter)
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(Smeh)
02:26
And not frozen water, and not water
in a gaseous state, but liquid water.
in a gaseous state, but liquid water.
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I to ne zamrznuta voda, i ne voda
u gasovitom stanju, već tečna voda.
u gasovitom stanju, već tečna voda.
02:32
This is what life needs
to survive, all life.
to survive, all life.
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Ovo je potrebno životu
za opstanak, svem životu.
za opstanak, svem životu.
02:35
And many solar system bodies
don't have liquid water,
don't have liquid water,
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A mnoga tela u solarnom sistemu
nemaju tečnu vodu,
nemaju tečnu vodu,
02:39
and so we don't look there.
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te zato tamo ne tražimo život.
02:40
Other solar system bodies
might have abundant liquid water,
might have abundant liquid water,
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Druga tela u solarnom sistemu
mogu da imaju obilje tečne vode,
mogu da imaju obilje tečne vode,
02:43
even more than Earth,
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čak i više nego Zemlja,
02:45
but it's trapped beneath an icy shell,
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ali je ona zarobljena ispod ledene opne,
te je teško njoj pristupiti,
teško je doći do nje,
teško je doći do nje,
02:47
and so it's hard to access,
it's hard to get to,
it's hard to get to,
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02:49
it's hard to even find out
if there's any life there.
if there's any life there.
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teško je čak i saznati
da li tamo uopšte ima života.
da li tamo uopšte ima života.
02:53
So that leaves a few bodies
that we should think about.
that we should think about.
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Stoga nam ostaje nekoliko tela
o kojima bi trebalo da mislimo.
o kojima bi trebalo da mislimo.
02:56
So let's make the problem
simpler for ourselves.
simpler for ourselves.
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Zato pojednostavimo problem zbog nas.
02:58
Let's think only about liquid water
on the surface of a planet.
on the surface of a planet.
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Razmišljajmo jedino o tečnoj vodi
na površini planete.
na površini planete.
Možemo da razmišljamo o svega tri tela
u našem solarnom sistemu,
u našem solarnom sistemu,
03:02
There are only three bodies
to think about in our solar system,
to think about in our solar system,
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03:05
with regard to liquid water
on the surface of a planet,
on the surface of a planet,
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u smislu tečne vode na površini planete,
03:07
and in order of distance from the sun,
it's: Venus, Earth and Mars.
it's: Venus, Earth and Mars.
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a prema udaljenosti od sunca
to su: Venera, Zemlja i Mars.
to su: Venera, Zemlja i Mars.
03:13
You want to have an atmosphere
for water to be liquid.
for water to be liquid.
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Potrebna vam je atmosfera
da bi voda bila tečna.
da bi voda bila tečna.
03:16
You have to be very careful
with that atmosphere.
with that atmosphere.
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Morate da budete veoma oprezni
s tom atmosferom.
s tom atmosferom.
03:19
You can't have too much atmosphere,
too thick or too warm an atmosphere,
too thick or too warm an atmosphere,
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Ne treba vam previše atmosfere,
pregusta ili pretopla atmosfera
pregusta ili pretopla atmosfera
03:22
because then you end up
too hot like Venus,
too hot like Venus,
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jer bi bilo suviše vrelo, kao na Veneri
03:25
and you can't have liquid water.
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i ne biste imali tečnu vodu.
03:27
But if you have too little atmosphere
and it's too thin and too cold,
and it's too thin and too cold,
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Ali ako imate premalo atmosfere
i ona je suviše retka i hladna,
i ona je suviše retka i hladna,
03:31
you end up like Mars, too cold.
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završite kao Mars, suviše hladni.
03:33
So Venus is too hot, Mars is too cold,
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Dakle, Venera je pretopla,
Mars je prehladan,
Mars je prehladan,
03:36
and Earth is just right.
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a Zemlja je potaman.
03:37
You can look at these images behind me
and you can see automatically
and you can see automatically
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Posmatrajući ove slike iza mene,
možete automatski da vidite
možete automatski da vidite
03:41
where life can survive
in our solar system.
in our solar system.
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gde je moguć opstanak života
u našem solarnom sistemu.
u našem solarnom sistemu.
03:44
It's a Goldilocks-type problem,
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To je tip problema "Zlatokosa",
03:45
and it's so simple
that a child could understand it.
that a child could understand it.
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i toliko je jednostavan
da dete može da ga razume.
da dete može da ga razume.
03:49
However,
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Međutim,
03:51
I'd like to remind you of two things
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voleo bih da vas podsetim na dve stvari
03:54
from the Goldilocks story
that we may not think about so often
that we may not think about so often
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iz priče o Zlatokosoj
o kojima možda ne razmišljamo tako često,
o kojima možda ne razmišljamo tako često,
03:57
but that I think are really relevant here.
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ali smatram da su zaista važne ovde.
04:00
Number one:
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Pod jedan:
04:02
if Mama Bear's bowl is too cold
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ako je činija mame medved suviše hladna
04:05
when Goldilocks walks into the room,
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kad Zlatokosa uđe u prostoriju,
04:08
does that mean it's always been too cold?
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da li to znači da je oduvek bila hladna?
04:11
Or could it have been just right
at some other time?
at some other time?
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Ili je u nekom drugom vremenu
bila baš kako treba?
bila baš kako treba?
04:15
When Goldilocks walks into the room
determines the answer
determines the answer
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Kad Zlatokosa uđe u prostoriju
određuje odgovor
određuje odgovor
04:19
that we get in the story.
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koji nam priča pruža.
04:21
And the same is true with planets.
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A isto je tako i s planetama.
04:22
They're not static things. They change.
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One nisu nešto statično. Menjaju se.
04:24
They vary. They evolve.
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Variraju. Razvijaju se.
04:26
And atmospheres do the same.
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A isto je i sa atmosferama.
04:28
So let me give you an example.
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Stoga ću da vam dam jedan primer.
04:30
Here's one of my favorite
pictures of Mars.
pictures of Mars.
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Ovo je među mojim omiljenim slikama Marsa.
04:32
It's not the highest resolution image,
it's not the sexiest image,
it's not the sexiest image,
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Nije to slika naročito visoke rezolucije,
nije ni naročito seksi,
nije ni naročito seksi,
04:35
it's not the most recent image,
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nije najskorija slika,
04:37
but it's an image that shows riverbeds
cut into the surface of the planet;
cut into the surface of the planet;
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ali je slika koja pokazuje rečna korita
kako seku površinu planete;
kako seku površinu planete;
04:41
riverbeds carved by flowing, liquid water;
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rečna korita koja je urezala
tekuća, tečna voda;
tekuća, tečna voda;
04:45
riverbeds that take hundreds or thousands
or tens of thousands of years to form.
or tens of thousands of years to form.
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korita koja su se oblikovala stotinama ili
hiljadama ili desetinama hiljada godina.
hiljadama ili desetinama hiljada godina.
04:50
This can't happen on Mars today.
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Ovo više nije moguće na Marsu.
04:52
The atmosphere of Mars today
is too thin and too cold
is too thin and too cold
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Danas je atmosfera na Marsu
suviše retka i hladna
suviše retka i hladna
04:54
for water to be stable as a liquid.
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da bi voda bila postojana kao tečnost.
04:56
This one image tells you
that the atmosphere of Mars changed,
that the atmosphere of Mars changed,
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Ova slika vam govori
da se atmosfera na Marsu promenila,
da se atmosfera na Marsu promenila,
05:01
and it changed in big ways.
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i to se promenila uveliko.
05:03
And it changed from a state
that we would define as habitable,
that we would define as habitable,
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A promenila se iz stanja
koje bismo odredili kao nastanjivo,
koje bismo odredili kao nastanjivo,
05:08
because the three requirements
for life were present long ago.
for life were present long ago.
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jer su tri uslova za život
nekad davno bila prisutna.
nekad davno bila prisutna.
05:13
Where did that atmosphere go
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Gde je nestala ta atmosfera
05:15
that allowed water
to be liquid at the surface?
to be liquid at the surface?
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koja je omogućavala vodi
da bude tečna na površini?
da bude tečna na površini?
05:17
Well, one idea is it escaped
away to space.
away to space.
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Pa, jedna od ideja
je da je izmakla u svemir.
je da je izmakla u svemir.
05:21
Atmospheric particles
got enough energy to break free
got enough energy to break free
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Atmosferske čestice
su dobile dovoljno energije
su dobile dovoljno energije
da se oslobode gravitacije planete,
05:24
from the gravity of the planet,
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05:25
escaping away to space, never to return.
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izmičući u svemir, bespovratno.
05:28
And this happens with all bodies
with atmospheres.
with atmospheres.
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A to se dešava svim telima s atmosferama.
05:31
Comets have tails
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Komete imaju repove
05:32
that are incredibly visible reminders
of atmospheric escape.
of atmospheric escape.
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koji su izuzetno očiti podsetnici
izmicanja atmosfere.
izmicanja atmosfere.
05:35
But Venus also has an atmosphere
that escapes with time,
that escapes with time,
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Ali Venera takođe ima atmosferu
koja vremenom izmiče,
koja vremenom izmiče,
05:39
and Mars and Earth as well.
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kao i Mars i Zemlja.
05:40
It's just a matter of degree
and a matter of scale.
and a matter of scale.
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Prosto se radi o stepenu i razmeri.
05:44
So we'd like to figure out
how much escaped over time
how much escaped over time
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Pa bismo voleli da otkrijemo
koliko je izmaklo vremenom,
koliko je izmaklo vremenom,
05:46
so we can explain this transition.
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kako bismo mogli da objasnimo ovaj prelaz.
05:48
How do atmospheres
get their energy for escape?
get their energy for escape?
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Kako atmosfere dobijaju energiju za beg?
05:51
How do particles get
enough energy to escape?
enough energy to escape?
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Kako čestice dobiju
dovoljno energije za beg?
dovoljno energije za beg?
05:53
There are two ways, if we're going
to reduce things a little bit.
to reduce things a little bit.
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Postoje dva načina, ako bismo želeli
da malo sažmemo stvari.
da malo sažmemo stvari.
05:56
Number one, sunlight.
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Prvo: sunčeva svetlost.
05:58
Light emitted from the sun can be absorbed
by atmospheric particles
by atmospheric particles
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Svetlost koju odašilja sunce
mogu da apsorbuju atmosferske čestice
mogu da apsorbuju atmosferske čestice
06:01
and warm the particles.
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čime se one zagrejavaju.
06:03
Yes, I'm dancing, but they --
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Da, plešem, ali one -
06:05
(Laughter)
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(Smeh)
06:07
Oh my God, not even at my wedding.
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Oh, gospode, nisam ni na svom venčanju.
06:09
(Laughter)
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(Smeh)
06:11
They get enough energy
to escape and break free
to escape and break free
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Dobiju dovoljno energije
da umaknu i oslobode se
da umaknu i oslobode se
06:14
from the gravity of the planet
just by warming.
just by warming.
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od gravitacije planete,
pukim zagrevanjem.
pukim zagrevanjem.
06:16
A second way they can get energy
is from the solar wind.
is from the solar wind.
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Drugi način na koji mogu
da dobiju energiju je solarni vetar.
da dobiju energiju je solarni vetar.
06:19
These are particles, mass, material,
spit out from the surface of the sun,
spit out from the surface of the sun,
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Ovo su čestice, mase, materijali
koje su ispljunute sa površine sunca
koje su ispljunute sa površine sunca
06:24
and they go screaming
through the solar system
through the solar system
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i one jurcaju kroz solarni sistem
06:27
at 400 kilometers per second,
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400 kilometara u sekundi,
06:29
sometimes faster during solar storms,
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ponekad i brže tokom solarnih oluja
06:31
and they go hurtling
through interplanetary space
through interplanetary space
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i one hrle kroz međuplanetarni prostor
06:34
towards planets and their atmospheres,
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ka planetama i njihovim atmosferama,
06:37
and they may provide energy
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a mogu i da pruže energiju
06:38
for atmospheric particles
to escape as well.
to escape as well.
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atmosferskim česticama da bi i one umakle.
06:41
This is something that I'm interested in,
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Ovo je nešto za šta sam zainteresovan
06:43
because it relates to habitability.
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jer ima veze s nastanjivošću.
06:45
I mentioned that there were two things
about the Goldilocks story
about the Goldilocks story
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Pomenuo sam dve stvari
iz priče o Zlatokosoj
iz priče o Zlatokosoj
06:48
that I wanted to bring to your attention
and remind you about,
and remind you about,
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na koje želim da vam skrenem pažnju
i da vas podsetim na njih,
i da vas podsetim na njih,
06:51
and the second one
is a little bit more subtle.
is a little bit more subtle.
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a druga je malčice finija.
06:53
If Papa Bear's bowl is too hot,
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Ako je činija tate medveda suviše vrela,
06:58
and Mama Bear's bowl is too cold,
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a činija mame medveda je suviše hladna,
07:03
shouldn't Baby Bear's bowl be even colder
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zar ne bi trebalo da je činija
bebe medveda čak i hladnija,
bebe medveda čak i hladnija,
07:07
if we're following the trend?
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ukoliko pratimo trend?
07:10
This thing that you've accepted
your entire life,
your entire life,
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Nešto što ste prihvatili čitav vaš život,
07:12
when you think about it a little bit more,
may not be so simple.
may not be so simple.
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kad razmislite o tome malo više,
možda i nije tako prosto.
možda i nije tako prosto.
07:16
And of course, distance of a planet
from the sun determines its temperature.
from the sun determines its temperature.
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I naravno da udaljenost planete od sunca
određuje njenu temperaturu.
određuje njenu temperaturu.
07:20
This has to play into habitability.
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Ovo se odražava na nastanjivost.
07:22
But maybe there are other things
we should be thinking about.
we should be thinking about.
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Ali možda ima nešto drugo
o čemu bi trebalo da mislimo.
o čemu bi trebalo da mislimo.
07:25
Maybe it's the bowls themselves
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Možda se radi o samim činijama
07:27
that are also helping to determine
the outcome in the story,
the outcome in the story,
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koje takođe pomažu u određivanju
ishoda priče,
ishoda priče,
07:30
what is just right.
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šta je taman kako treba.
07:32
I could talk to you about a lot
of different characteristics
of different characteristics
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Mogao bih mnogo da vam govorim
o različitim osobinama
o različitim osobinama
07:35
of these three planets
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ove tri planete,
07:36
that may influence habitability,
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koje možda utiču na nastanjivost,
07:38
but for selfish reasons related
to my own research
to my own research
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ali iz sebičnih razloga
u vezi s mojim istraživanjem,
u vezi s mojim istraživanjem,
07:41
and the fact that I'm standing up here
holding the clicker and you're not --
holding the clicker and you're not --
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i zbog činjenice da ja stojim ovde gore
i držim daljinski, a ne vi -
i držim daljinski, a ne vi -
07:44
(Laughter)
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(Smeh)
07:45
I would like to talk
for just a minute or two
for just a minute or two
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želeo bih da govorim samo minut ili dva
07:47
about magnetic fields.
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o magnetnim poljima.
07:49
Earth has one; Venus and Mars do not.
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Zemlja ga ima; Venera i Mars nemaju.
07:52
Magnetic fields are generated
in the deep interior of a planet
in the deep interior of a planet
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Magnetna polja nastaju
u dubokoj unutrašnjosti planete
u dubokoj unutrašnjosti planete
07:55
by electrically conducting
churning fluid material
churning fluid material
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električnim provođenjem
uskovitlanih tečnih materijala
uskovitlanih tečnih materijala
07:59
that creates this big old magnetic field
that surrounds Earth.
that surrounds Earth.
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što stvara veliko staro magnetno polje
koje okružuje Zemlju.
koje okružuje Zemlju.
08:02
If you have a compass,
you know which way north is.
you know which way north is.
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Ako imate kompas,
znate na kojoj strani je sever.
znate na kojoj strani je sever.
08:05
Venus and Mars don't have that.
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Venera i Mars to nemaju.
08:06
If you have a compass on Venus and Mars,
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1914
Ako imate kompas na Veneri i Marsu,
08:08
congratulations, you're lost.
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čestitam, zalutali ste.
08:09
(Laughter)
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(Smeh)
08:11
Does this influence habitability?
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2040
Da li ovo utiče na nastanjivost?
08:15
Well, how might it?
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Pa, kako bi moglo?
08:17
Many scientists think
that a magnetic field of a planet
that a magnetic field of a planet
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Mnogi naučnici smatraju
da magnetno polje planete
da magnetno polje planete
08:19
serves as a shield for the atmosphere,
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služi kao štit za atmosferu,
08:22
deflecting solar wind particles
around the planet
around the planet
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koji odbija čestice solarnih vetrova
oko planete
oko planete
08:25
in a bit of a force field-type effect
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u nekoj vrsti blagog efekta sile polja
08:27
having to do with electric charge
of those particles.
of those particles.
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koja je u vezi sa električnim nabojem
tih čestica.
tih čestica.
08:30
I like to think of it instead
as a salad bar sneeze guard for planets.
as a salad bar sneeze guard for planets.
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Pre to vidim kao o zaklonu od kašlja
za planete u vidu šanka za salatu.
za planete u vidu šanka za salatu.
08:34
(Laughter)
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502013
2279
(Smeh)
08:36
And yes, my colleagues
who watch this later will realize
who watch this later will realize
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I da, moje kolege,
koje će ovo kasnije da gledaju, će uvideti
koje će ovo kasnije da gledaju, će uvideti
08:40
this is the first time in the history
of our community
of our community
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da je ovo prvi put
u istoriji naše zajednice
u istoriji naše zajednice
08:42
that the solar wind has been
equated with mucus.
equated with mucus.
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da je solarni vetar poistovećen sa sluzi.
08:45
(Laughter)
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(Smeh)
08:48
OK, so the effect, then, is that Earth
may have been protected
may have been protected
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3475
U redu, posledica toga
je da je Zemlja možda zaštićena
je da je Zemlja možda zaštićena
08:52
for billions of years,
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milijardama godina
08:53
because we've had a magnetic field.
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jer ima magnetno polje.
08:55
Atmosphere hasn't been able to escape.
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2179
Atmosfera nije mogla da umakne.
08:57
Mars, on the other hand,
has been unprotected
has been unprotected
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2107
Mars, s druge strane, je bio nezaštićen
08:59
because of its lack of magnetic field,
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zbog nedostatka magnetnog polja,
09:01
and over billions of years,
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529744
1952
i tokom milijardi godina
09:03
maybe enough atmosphere
has been stripped away
has been stripped away
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531720
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je možda dovoljna
količina atmosfere guljena
količina atmosfere guljena
09:05
to account for a transition
from a habitable planet
from a habitable planet
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do te mere da on pređe
iz nastanjive planete
iz nastanjive planete
09:08
to the planet that we see today.
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do planete koju vidimo danas.
09:11
Other scientists think
that magnetic fields
that magnetic fields
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Drugi naučnici smatraju
da magnetna polja
da magnetna polja
09:14
may act more like the sails on a ship,
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možda deluju poput jedara na brodu,
09:16
enabling the planet to interact
with more energy from the solar wind
with more energy from the solar wind
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5037
koja omogućuju planeti da interaguje
s više energije iz solarnih vetrova
s više energije iz solarnih vetrova
09:22
than the planet would have been able
to interact with by itself.
to interact with by itself.
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550019
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nego što bi planeta sama
bila u stanju da interaguje.
bila u stanju da interaguje.
09:25
The sails may gather energy
from the solar wind.
from the solar wind.
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2491
Jedra možda sakupljaju energiju
iz solarnog vetra.
iz solarnog vetra.
09:27
The magnetic field may gather
energy from the solar wind
energy from the solar wind
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555830
2666
Magnetno polje možda sakuplja
energiju iz solarnog vetra
energiju iz solarnog vetra
09:30
that allows even more
atmospheric escape to happen.
atmospheric escape to happen.
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558520
3244
koja omogućuje da se još više
atmosferskog izmicanja desi.
atmosferskog izmicanja desi.
09:33
It's an idea that has to be tested,
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2254
To je zamisao koja mora da se testira,
09:36
but the effect and how it works
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1885
ali njeni efekti i to kako deluje
09:37
seems apparent.
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1151
se čine očiglednim.
09:39
That's because we know
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567150
1151
To je zato što znamo
09:40
energy from the solar wind
is being deposited into our atmosphere
is being deposited into our atmosphere
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568325
3075
da se energija iz solarnog vetra
skladišti u našoj atmosferi
skladišti u našoj atmosferi
09:43
here on Earth.
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1151
ovde na Zemlji.
09:44
That energy is conducted
along magnetic field lines
along magnetic field lines
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2405
Ta energija se sprovodi
duž linija magnetnog polja
duž linija magnetnog polja
09:47
down into the polar regions,
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575028
1348
dole do polarnih oblasti,
09:48
resulting in incredibly beautiful aurora.
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576400
2136
rezultirajući predivnom
polarnom svetlošću.
polarnom svetlošću.
09:50
If you've ever experienced them,
it's magnificent.
it's magnificent.
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2656
Ako ste to iskusili, veličanstveno je.
09:53
We know the energy is getting in.
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581240
2006
Znamo da energija dolazi unutra.
09:55
We're trying to measure
how many particles are getting out
how many particles are getting out
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3033
Pokušavamo da izmerimo
koliko čestica izlazi napolje
koliko čestica izlazi napolje
09:58
and if the magnetic field
is influencing this in any way.
is influencing this in any way.
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586327
3038
i da li magnetno polje
na bilo koji način utiče na to.
na bilo koji način utiče na to.
10:02
So I've posed a problem for you here,
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2380
Dakle, postavio sam vam problem ovde,
10:05
but I don't have a solution yet.
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1546
ali još uvek nemam rešenje.
10:06
We don't have a solution.
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594696
1276
Nemamo rešenje.
10:08
But we're working on it.
How are we working on it?
How are we working on it?
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596702
2357
Ali radimo na tome. Kako radimo na tome?
10:11
Well, we've sent spacecraft
to all three planets.
to all three planets.
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599083
2298
Poslali smo kosmičke brodove
na sve tri planete.
na sve tri planete.
10:13
Some of them are orbiting now,
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1476
Neki od njih upravo kruže,
10:14
including the MAVEN spacecraft
which is currently orbiting Mars,
which is currently orbiting Mars,
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3072
uključujući svemirski brod MAVEN
koji trenutno kruži oko Marsa,
koji trenutno kruži oko Marsa,
10:18
which I'm involved with
and which is led here,
and which is led here,
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3532
u to sam uključen
i time se upravlja odavde,
i time se upravlja odavde,
10:21
out of the University of Colorado.
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1809
sa Univerziteta u Koloradu.
10:23
It's designed to measure
atmospheric escape.
atmospheric escape.
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611390
2282
Dizajniran je da meri
atmosferska izmicanja.
atmosferska izmicanja.
10:26
We have similar measurements
from Venus and Earth.
from Venus and Earth.
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2474
Imamo slična merenja sa Venere i Zemlje.
10:28
Once we have all our measurements,
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1665
Čim dobijemo sva merenja,
10:30
we can combine all these together,
and we can understand
and we can understand
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2875
možemo da kombinujemo sve njih zajedno
i možemo da razumemo
i možemo da razumemo
10:33
how all three planets interact
with their space environment,
with their space environment,
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621541
3417
kako sve tri palente interaguju
sa svojim svemirskim okruženjem,
sa svojim svemirskim okruženjem,
10:36
with the surroundings.
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1162
sa okolinom.
10:38
And we can decide whether magnetic fields
are important for habitability
are important for habitability
238
626168
3522
I možemo da odredimo da li su
magnetna polja važna za nastanjivost
magnetna polja važna za nastanjivost
10:41
or not.
239
629714
1158
ili nisu.
10:42
Once we have that answer,
why should you care?
why should you care?
240
630896
2265
Zašto biste marili za taj odgovor?
10:45
I mean, I care deeply ...
241
633185
1300
Mislim, ja veoma marim...
10:48
And financially as well, but deeply.
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636128
2006
I finansijski, ali veoma.
10:50
(Laughter)
243
638158
1842
(Smeh)
10:52
First of all, an answer to this question
244
640763
1918
Pre svega, odgovorom na ovo pitanje
10:54
will teach us more
about these three planets,
about these three planets,
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2103
ćemo više naučiti o ove tri planete,
10:56
Venus, Earth and Mars,
246
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1160
Veneri, Zemlji i Marsu,
10:58
not only about how they interact
with their environment today,
with their environment today,
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2911
ne samo kako interaguju
trenutno sa svojim okruženjima,
trenutno sa svojim okruženjima,
11:00
but how they were billions of years ago,
248
648951
1927
već kakve su bile pre milijardu godina,
11:02
whether they were habitable
long ago or not.
long ago or not.
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650902
2062
da li su nekad davno
bile nastanjive ili ne.
bile nastanjive ili ne.
11:04
It will teach us about atmospheres
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1644
Naučićemo o atmosferama
11:06
that surround us and that are close.
251
654656
1995
koje nas okružuju i koje su blizu.
11:09
But moreover, what we learn
from these planets
from these planets
252
657127
2184
Ali, štaviše, ono što naučimo
od ovih planeta
od ovih planeta
11:11
can be applied to atmospheres everywhere,
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659335
2021
može da se primeni na atmosfere svuda,
uključujući planete koje trenutno
posmatramo oko drugih zvezda.
posmatramo oko drugih zvezda.
11:14
including planets that we're now
observing around other stars.
observing around other stars.
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662485
2913
11:17
For example, the Kepler spacecraft,
255
665422
1755
Na primer, kosmički brod Kepler,
11:19
which is built and controlled
here in Boulder,
here in Boulder,
256
667201
3208
koji je napravljen i njime se upravlja
odavde iz Boldera,
odavde iz Boldera,
11:22
has been observing
a postage stamp-sized region of the sky
a postage stamp-sized region of the sky
257
670433
3285
posmatra predeo neba
veličine poštanske markice
veličine poštanske markice
11:25
for a couple years now,
258
673742
1247
već nekoliko godina,
11:27
and it's found thousands of planets --
259
675013
2228
i otkrio je na hiljade planeta -
11:29
in one postage stamp-sized
region of the sky
region of the sky
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677265
2913
u jednom predelu neba
veličine poštanske markice
veličine poštanske markice
11:32
that we don't think is any different
from any other part of the sky.
from any other part of the sky.
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680202
4089
koji ne smatramo iole različitim
od bilo kog drugog dela neba.
od bilo kog drugog dela neba.
11:36
We've gone, in 20 years,
262
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1810
Prešli smo, za 20 godina,
11:38
from knowing of zero planets
outside of our solar system,
outside of our solar system,
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686649
4037
od poznavanja nula planeta
van našeg solarnog sistema,
van našeg solarnog sistema,
11:42
to now having so many,
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690710
1753
do toga da ih imamo toliko,
11:44
that we don't know
which ones to investigate first.
which ones to investigate first.
265
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3139
da ne znamo koje prvo da istražujemo.
11:49
Any lever will help.
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1460
Svako oruđe može da pomogne.
11:52
In fact, based on observations
that Kepler's taken
that Kepler's taken
267
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3584
Zapravo, na osnovu zapažanja
koja je napravio Kepler,
koja je napravio Kepler,
11:56
and other similar observations,
268
704147
2129
i drugih sličnih zapažanja,
11:58
we now believe that,
269
706300
1169
trenutno verujemo da,
11:59
of the 200 billion stars
in the Milky Way galaxy alone,
in the Milky Way galaxy alone,
270
707493
4699
od 200 milijardi zvezda
samo u galaksiji Mlečni put,
samo u galaksiji Mlečni put,
12:04
on average, every star
has at least one planet.
has at least one planet.
271
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4604
u proseku, svaka zvezda
ima bar jednu planetu.
ima bar jednu planetu.
12:10
In addition to that,
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1503
Uz to,
12:12
estimates suggest there are somewhere
between 40 billion and 100 billion
between 40 billion and 100 billion
273
720346
5701
procenjuje se da ima otprilike
između 40 milijardi i 100 milijardi
između 40 milijardi i 100 milijardi
12:18
of those planets
that we would define as habitable
that we would define as habitable
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3332
planeta koje bismo odredili kao nastanjive
12:23
in just our galaxy.
275
731139
1412
samo u našoj galaksiji.
12:26
We have the observations of those planets,
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2037
Imamo zapažanja s tih planeta,
12:28
but we just don't know
which ones are habitable yet.
which ones are habitable yet.
277
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2484
ali prosto još uvek ne znamo
koje su nastanjive.
koje su nastanjive.
12:31
It's a little bit like
being trapped on a red spot --
being trapped on a red spot --
278
739159
3606
Pomalo podseća na zarobljenost
na crvenoj tački -
na crvenoj tački -
12:34
(Laughter)
279
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1171
(Smeh)
12:35
on a stage
280
743984
1232
na sceni
12:38
and knowing that there are
other worlds out there
other worlds out there
281
746178
3562
i saznanje da postoje
drugi svetovi tamo negde
drugi svetovi tamo negde
12:43
and desperately wanting to know
more about them,
more about them,
282
751042
2776
i na očajničku želju
da znate više o njima,
da znate više o njima,
12:47
wanting to interrogate them and find out
if maybe just one or two of them
if maybe just one or two of them
283
755174
3934
želite da ih ispitate i otkrijete
da li možda bar jedan ili dva od njih
da li možda bar jedan ili dva od njih
12:51
are a little bit like you.
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759132
1610
bar malo liče na vas.
Ne možete to da učinite.
Ne možete i dalje da odete tamo.
Ne možete i dalje da odete tamo.
12:54
You can't do that.
You can't go there, not yet.
You can't go there, not yet.
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12:56
And so you have to use the tools
that you've developed around you
that you've developed around you
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Te morate da koristite oruđa
oko vas koja ste razvili
oko vas koja ste razvili
13:00
for Venus, Earth and Mars,
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za Veneru, Zemlju i Mars,
13:02
and you have to apply them
to these other situations,
to these other situations,
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i morate da ih primenite
u tim ostalim situacijama,
u tim ostalim situacijama,
13:05
and hope that you're making
reasonable inferences from the data,
reasonable inferences from the data,
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i da se nadate da izvodite
razumne zaključke iz podataka
razumne zaključke iz podataka
13:09
and that you're going to be able
to determine the best candidates
to determine the best candidates
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i da ćete biti u stanju
da odredite najbolje kandidate
da odredite najbolje kandidate
13:12
for habitable planets,
and those that are not.
and those that are not.
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za nastanjive planete, i one koji to nisu.
13:16
In the end, and for now, at least,
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I, naposletku, bar za sad,
13:18
this is our red spot, right here.
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ovo je naša crvena tačka - tačno tu.
13:22
This is the only planet
that we know of that's habitable,
that we know of that's habitable,
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Ovo je jedina planeta
za koju znamo da je nastanjiva,
za koju znamo da je nastanjiva,
13:25
although very soon we may
come to know of more.
come to know of more.
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iako ćemo veoma brzo
saznati za mnoge druge.
saznati za mnoge druge.
13:28
But for now, this is
the only habitable planet,
the only habitable planet,
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Ali za sad,
ovo je jedina nastanjiva planeta
ovo je jedina nastanjiva planeta
13:31
and this is our red spot.
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i ovo je naša crvena tačka.
13:33
I'm really glad we're here.
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Baš mi je drago da smo ovde.
13:36
Thanks.
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Hvala.
13:37
(Applause)
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(Aplauz)
ABOUT THE SPEAKER
Dave Brain - Planetary scientistDave Brain studies the plasma environments and atmospheres of unmagnetized planets.
Why you should listen
Dave Brain is an Assistant Professor of Astrophysics and Planetary Science at the University of Colorado at Boulder. He's interested in the evolution of the atmospheres of planets such as Mars, Venus and Earth, and in particular how planets lose (and gain) atmosphere over time. He uses spacecraft data and computer models to help figure out how light and particles from our sun strip away atmospheric particles, possibly changing them from habitable worlds.
More profile about the speakerDave Brain | Speaker | TED.com