Distant time and the hint of a multiverse - Sean Carroll
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the<00:00:16.640> universe<00:00:17.640> is<00:00:17.960> really<00:00:18.680> big<00:00:19.680> we<00:00:19.880> live<00:00:20.240> in<00:00:20.519> a
the universe is really big we live in a
the universe is really big we live in a
galaxy<00:00:21.240> The<00:00:21.359> Milky<00:00:21.680> Way<00:00:21.920> galaxy<00:00:22.320> there<00:00:22.519> about
galaxy The Milky Way galaxy there about
galaxy The Milky Way galaxy there about
a<00:00:22.880> 100<00:00:23.240> billion<00:00:23.720> stars<00:00:24.400> in<00:00:24.519> the<00:00:24.640> Milky<00:00:24.960> Way
a 100 billion stars in the Milky Way
a 100 billion stars in the Milky Way
galaxy<00:00:26.119> and<00:00:26.240> if<00:00:26.320> you<00:00:26.480> take<00:00:26.599> a<00:00:26.840> camera<00:00:27.679> and<00:00:27.800> you
galaxy and if you take a camera and you
galaxy and if you take a camera and you
point<00:00:28.199> it<00:00:28.359> at<00:00:28.480> a<00:00:28.640> random<00:00:29.000> part<00:00:29.199> of<00:00:29.320> the<00:00:29.519> sky<00:00:30.039> and
point it at a random part of the sky and
point it at a random part of the sky and
you<00:00:30.279> just<00:00:30.439> keep<00:00:30.599> the<00:00:30.720> shutter<00:00:31.160> open<00:00:32.040> as<00:00:32.160> long
you just keep the shutter open as long
you just keep the shutter open as long
as<00:00:32.439> your<00:00:32.680> camera<00:00:33.040> is<00:00:33.200> attached<00:00:33.520> to<00:00:33.640> the<00:00:33.760> Hubble
as your camera is attached to the Hubble
as your camera is attached to the Hubble
Space<00:00:34.360> Telescope<00:00:34.920> it<00:00:35.000> will<00:00:35.160> see<00:00:35.399> something
Space Telescope it will see something
Space Telescope it will see something
like<00:00:36.640> this<00:00:37.640> every<00:00:37.960> one<00:00:38.120> of<00:00:38.280> these<00:00:38.440> little
like this every one of these little
like this every one of these little
blobs<00:00:39.520> is<00:00:39.760> a<00:00:40.039> Galaxy<00:00:40.640> roughly<00:00:40.960> the<00:00:41.079> size<00:00:41.239> of
blobs is a Galaxy roughly the size of
blobs is a Galaxy roughly the size of
our<00:00:41.520> Milky<00:00:41.840> Way<00:00:42.200> 100<00:00:42.440> billion<00:00:43.079> stars<00:00:43.440> in<00:00:43.600> each
our Milky Way 100 billion stars in each
our Milky Way 100 billion stars in each
of<00:00:43.920> those<00:00:44.120> blobs<00:00:44.960> there<00:00:45.039> are<00:00:45.200> approximately
of those blobs there are approximately
of those blobs there are approximately
100<00:00:46.199> billion<00:00:46.960> galaxies<00:00:47.879> in<00:00:48.199> the<00:00:48.360> observable
100 billion galaxies in the observable
100 billion galaxies in the observable
universe<00:00:49.520> the<00:00:49.800> 100<00:00:50.039> billion<00:00:50.320> is<00:00:50.399> the<00:00:50.520> only
universe the 100 billion is the only
universe the 100 billion is the only
number<00:00:51.079> you<00:00:51.199> need<00:00:51.360> to<00:00:51.520> know<00:00:52.079> the<00:00:52.280> age<00:00:52.480> of<00:00:52.600> the
number you need to know the age of the
number you need to know the age of the
universe<00:00:53.199> between<00:00:53.480> now<00:00:53.600> and<00:00:53.719> the<00:00:53.800> Big<00:00:54.039> Bang<00:00:54.239> is
universe between now and the Big Bang is
universe between now and the Big Bang is
100<00:00:54.800> billion<00:00:55.520> in<00:00:55.800> dog
100 billion in dog
100 billion in dog
years<00:00:58.920> which<00:00:59.079> tells<00:00:59.280> you<00:00:59.440> something<00:00:59.680> about
years which tells you something about
years which tells you something about
our<00:01:00.199> place<00:01:00.640> in<00:01:00.760> the<00:01:00.920> universe<00:01:01.920> one<00:01:02.079> thing<00:01:02.239> you
our place in the universe one thing you
our place in the universe one thing you
can<00:01:02.440> do<00:01:02.600> with<00:01:02.719> a<00:01:02.840> picture<00:01:03.199> like<00:01:03.440> this<00:01:03.719> is
can do with a picture like this is
can do with a picture like this is
simply<00:01:04.320> admire<00:01:04.680> it<00:01:04.879> it's<00:01:05.119> extremely
simply admire it it's extremely
simply admire it it's extremely
beautiful<00:01:06.000> I've<00:01:06.159> often<00:01:06.360> wondered<00:01:06.720> what<00:01:06.840> is
beautiful I've often wondered what is
beautiful I've often wondered what is
the<00:01:07.119> evolutionary<00:01:07.880> pressure<00:01:08.240> that<00:01:08.400> made<00:01:08.960> our
the evolutionary pressure that made our
the evolutionary pressure that made our
ancestors<00:01:09.840> in<00:01:10.000> the<00:01:10.159> velt<00:01:10.680> adapt<00:01:11.240> and<00:01:11.439> evolve
ancestors in the velt adapt and evolve
ancestors in the velt adapt and evolve
to<00:01:12.159> really<00:01:12.600> enjoy<00:01:13.040> pictures<00:01:13.360> of<00:01:13.640> galaxies
to really enjoy pictures of galaxies
to really enjoy pictures of galaxies
when<00:01:14.400> they<00:01:14.520> didn't<00:01:14.799> have<00:01:15.000> any<00:01:15.920> but<00:01:16.040> we<00:01:16.119> would
when they didn't have any but we would
when they didn't have any but we would
also<00:01:16.439> like<00:01:16.560> to<00:01:17.080> understand<00:01:17.320> it<00:01:17.520> as<00:01:17.600> a
also like to understand it as a
also like to understand it as a
cosmologist<00:01:18.320> I<00:01:18.400> want<00:01:18.520> to<00:01:18.680> ask<00:01:19.080> why<00:01:19.479> is<00:01:19.640> the
cosmologist I want to ask why is the
cosmologist I want to ask why is the
universe<00:01:20.320> like<00:01:20.640> this<00:01:21.400> one<00:01:21.640> big<00:01:21.840> clue<00:01:22.119> we<00:01:22.280> have
universe like this one big clue we have
universe like this one big clue we have
is<00:01:22.560> that<00:01:22.680> the<00:01:22.759> universe<00:01:23.079> is<00:01:23.280> changing<00:01:24.119> with
is that the universe is changing with
is that the universe is changing with
time<00:01:24.799> if<00:01:24.880> you<00:01:25.119> looked<00:01:25.360> at<00:01:25.439> one<00:01:25.560> of<00:01:25.640> these
time if you looked at one of these
time if you looked at one of these
galaxies<00:01:26.200> and<00:01:26.320> measured<00:01:26.640> its<00:01:26.880> velocity<00:01:27.720> it
galaxies and measured its velocity it
galaxies and measured its velocity it
would<00:01:27.920> be<00:01:28.040> moving<00:01:28.400> away<00:01:28.799> from<00:01:29.079> you<00:01:29.720> and<00:01:29.880> and<00:01:29.920> if
would be moving away from you and and if
would be moving away from you and and if
you<00:01:30.079> look<00:01:30.159> at<00:01:30.240> a<00:01:30.400> Galaxy<00:01:30.759> even<00:01:30.960> further<00:01:31.280> away
you look at a Galaxy even further away
you look at a Galaxy even further away
it<00:01:31.560> would<00:01:31.680> be<00:01:31.799> moving<00:01:32.119> away<00:01:32.759> faster<00:01:33.560> so<00:01:33.720> we<00:01:33.840> say
it would be moving away faster so we say
it would be moving away faster so we say
the<00:01:34.159> universe<00:01:34.520> is<00:01:35.000> expanding<00:01:36.000> what<00:01:36.119> that
the universe is expanding what that
the universe is expanding what that
means<00:01:36.560> of<00:01:36.680> course<00:01:36.840> is<00:01:36.960> that<00:01:37.119> in<00:01:37.240> the<00:01:37.520> past
means of course is that in the past
means of course is that in the past
things<00:01:38.280> were<00:01:38.520> closer<00:01:39.079> together<00:01:39.720> in<00:01:39.840> the<00:01:40.040> past
things were closer together in the past
things were closer together in the past
the<00:01:40.399> universe<00:01:40.840> was<00:01:41.000> more<00:01:41.360> dense<00:01:41.960> and<00:01:42.040> it<00:01:42.119> was
the universe was more dense and it was
the universe was more dense and it was
also<00:01:42.600> hotter<00:01:43.000> if<00:01:43.119> you<00:01:43.200> squeeze<00:01:43.640> things
also hotter if you squeeze things
also hotter if you squeeze things
together<00:01:44.240> the<00:01:44.360> temperature<00:01:44.799> goes<00:01:45.040> up<00:01:45.600> that
together the temperature goes up that
together the temperature goes up that
kind<00:01:46.040> of<00:01:46.240> makes<00:01:46.520> sense<00:01:46.759> to<00:01:47.000> us<00:01:47.680> the<00:01:47.799> thing<00:01:47.960> that
kind of makes sense to us the thing that
kind of makes sense to us the thing that
doesn't<00:01:48.399> make<00:01:48.600> sense<00:01:48.840> to<00:01:49.000> us<00:01:49.240> as<00:01:49.399> much<00:01:49.640> is<00:01:49.759> that
doesn't make sense to us as much is that
doesn't make sense to us as much is that
the<00:01:50.040> Universe<00:01:50.479> at<00:01:50.640> Early<00:01:51.000> times<00:01:51.320> near<00:01:51.560> the<00:01:51.719> Big
the Universe at Early times near the Big
the Universe at Early times near the Big
Bang<00:01:52.640> was<00:01:52.840> also<00:01:53.200> very<00:01:53.479> very
Bang was also very very
Bang was also very very
smooth<00:01:55.399> you<00:01:55.560> might<00:01:55.759> think<00:01:55.920> that<00:01:56.039> that's<00:01:56.200> not<00:01:56.320> a
smooth you might think that that's not a
smooth you might think that that's not a
surprise<00:01:56.880> the<00:01:57.000> air<00:01:57.159> in<00:01:57.320> this<00:01:57.479> room<00:01:57.759> is<00:01:57.960> very
surprise the air in this room is very
surprise the air in this room is very
smooth<00:01:58.479> you<00:01:58.600> might<00:01:58.759> say<00:01:59.000> well<00:01:59.200> maybe<00:01:59.479> things
smooth you might say well maybe things
smooth you might say well maybe things
just<00:02:00.000> smooth<00:02:00.479> themselves<00:02:00.759> out<00:02:01.439> but<00:02:01.560> the
just smooth themselves out but the
just smooth themselves out but the
conditions<00:02:02.399> near<00:02:02.600> the<00:02:02.759> Big<00:02:03.000> Bang<00:02:03.360> are<00:02:03.600> very
conditions near the Big Bang are very
conditions near the Big Bang are very
very<00:02:04.119> different<00:02:04.479> than<00:02:04.600> the<00:02:04.840> conditions<00:02:05.079> of
very different than the conditions of
very different than the conditions of
the<00:02:05.320> air<00:02:05.520> in<00:02:05.640> this<00:02:05.799> room<00:02:06.200> in<00:02:06.360> particular
the air in this room in particular
the air in this room in particular
things<00:02:07.399> were<00:02:07.600> a<00:02:07.680> lot<00:02:08.039> denser<00:02:08.560> the
things were a lot denser the
things were a lot denser the
gravitational<00:02:10.080> pull<00:02:10.679> of<00:02:10.879> things<00:02:11.160> was<00:02:11.319> a<00:02:11.440> lot
gravitational pull of things was a lot
gravitational pull of things was a lot
stronger<00:02:12.040> near<00:02:12.239> the<00:02:12.400> Big<00:02:12.640> Bang<00:02:13.440> what<00:02:13.560> you<00:02:13.680> have
stronger near the Big Bang what you have
stronger near the Big Bang what you have
to<00:02:14.000> think<00:02:14.200> about<00:02:14.560> is<00:02:15.120> we<00:02:15.239> have<00:02:15.360> a<00:02:15.480> universe
to think about is we have a universe
to think about is we have a universe
with<00:02:16.280> 100<00:02:16.519> billion<00:02:16.879> galaxies<00:02:17.519> 100<00:02:17.720> billion
with 100 billion galaxies 100 billion
with 100 billion galaxies 100 billion
stars<00:02:18.480> each<00:02:19.120> at<00:02:19.239> Early<00:02:19.720> Times<00:02:20.239> those<00:02:20.519> 100
stars each at Early Times those 100
stars each at Early Times those 100
billion<00:02:21.120> galaxies<00:02:21.680> were<00:02:21.879> squeezed<00:02:22.360> into<00:02:22.599> a
billion galaxies were squeezed into a
billion galaxies were squeezed into a
region<00:02:23.239> about<00:02:23.640> this<00:02:24.360> bake<00:02:25.120> literally<00:02:25.599> at
region about this bake literally at
region about this bake literally at
Early<00:02:26.080> times<00:02:26.400> and<00:02:26.519> you<00:02:26.640> have<00:02:26.720> to<00:02:26.920> imagine
Early times and you have to imagine
Early times and you have to imagine
doing<00:02:27.640> that<00:02:27.959> squeezing<00:02:28.959> without<00:02:29.200> any<00:02:29.400> imper<00:02:29.840> C
doing that squeezing without any imper C
doing that squeezing without any imper C
without<00:02:31.120> any<00:02:31.560> little<00:02:32.400> spots<00:02:32.720> where<00:02:32.840> there
without any little spots where there
without any little spots where there
were<00:02:33.080> a<00:02:33.160> few<00:02:33.360> more<00:02:33.560> atoms<00:02:33.920> than<00:02:34.080> somewhere
were a few more atoms than somewhere
were a few more atoms than somewhere
else<00:02:34.720> CU<00:02:34.879> if<00:02:35.040> there<00:02:35.239> had<00:02:35.440> been<00:02:35.879> they<00:02:36.000> would
else CU if there had been they would
else CU if there had been they would
have<00:02:36.280> collapsed<00:02:36.760> under<00:02:36.959> the<00:02:37.120> gravitational
have collapsed under the gravitational
have collapsed under the gravitational
pull<00:02:38.040> into<00:02:38.239> a<00:02:38.400> huge<00:02:38.680> black<00:02:39.000> hole<00:02:40.000> keeping<00:02:40.319> the
pull into a huge black hole keeping the
pull into a huge black hole keeping the
universe<00:02:40.959> very<00:02:41.200> very<00:02:41.480> smooth<00:02:41.959> at<00:02:42.120> Early<00:02:42.519> times
universe very very smooth at Early times
universe very very smooth at Early times
is<00:02:43.159> not<00:02:43.640> easy<00:02:43.959> it's<00:02:44.080> a<00:02:44.239> delicate<00:02:44.599> Arrangement
is not easy it's a delicate Arrangement
is not easy it's a delicate Arrangement
it's<00:02:45.280> a<00:02:45.440> clue<00:02:46.360> that<00:02:46.480> the<00:02:46.599> early<00:02:46.879> universe<00:02:47.280> is
it's a clue that the early universe is
it's a clue that the early universe is
not<00:02:48.040> chosen<00:02:48.560> randomly<00:02:49.040> there<00:02:49.120> was<00:02:49.319> something
not chosen randomly there was something
not chosen randomly there was something
that<00:02:49.800> made<00:02:49.959> it<00:02:50.200> that<00:02:50.360> way<00:02:50.560> we<00:02:50.680> would<00:02:50.840> like<00:02:50.959> to
that made it that way we would like to
that made it that way we would like to
know<00:02:51.720> what<00:02:52.640> so<00:02:52.840> part<00:02:53.000> of<00:02:53.200> our<00:02:53.599> understanding
know what so part of our understanding
know what so part of our understanding
of<00:02:54.040> this<00:02:54.159> was<00:02:54.319> given<00:02:54.519> to<00:02:54.680> us<00:02:54.840> by<00:02:54.959> ludvic
of this was given to us by ludvic
of this was given to us by ludvic
boltzman<00:02:55.920> an<00:02:56.080> Austrian<00:02:56.519> physicist<00:02:56.920> in<00:02:57.000> the
boltzman an Austrian physicist in the
boltzman an Austrian physicist in the
19th<00:02:57.599> century<00:02:58.400> and<00:02:58.519> boltzman's<00:02:59.120> contribution
19th century and boltzman's contribution
19th century and boltzman's contribution
was<00:02:59.840> that<00:02:59.959> he<00:03:00.080> helped<00:03:00.319> us<00:03:00.800> understand<00:03:01.239> entropy
was that he helped us understand entropy
was that he helped us understand entropy
you've<00:03:02.440> heard<00:03:02.599> of<00:03:02.760> entropy<00:03:03.200> it's<00:03:03.360> the
you've heard of entropy it's the
you've heard of entropy it's the
randomness<00:03:04.159> the<00:03:04.400> disorder<00:03:05.000> the<00:03:05.159> chaoticness
randomness the disorder the chaoticness
randomness the disorder the chaoticness
of<00:03:06.040> some<00:03:06.319> system<00:03:07.159> boltzman<00:03:07.599> gave<00:03:07.799> us<00:03:07.920> a
of some system boltzman gave us a
of some system boltzman gave us a
formula<00:03:08.599> engraved<00:03:09.000> on<00:03:09.120> his<00:03:09.280> Tombstone<00:03:09.920> now<00:03:10.720> uh
formula engraved on his Tombstone now uh
formula engraved on his Tombstone now uh
that<00:03:11.040> really<00:03:11.319> quantifies<00:03:11.959> what<00:03:12.120> entropy<00:03:12.640> is
that really quantifies what entropy is
that really quantifies what entropy is
and<00:03:12.920> it's<00:03:13.080> basically<00:03:13.480> just<00:03:13.640> saying<00:03:14.040> that
and it's basically just saying that
and it's basically just saying that
entropy<00:03:14.959> is<00:03:15.080> the<00:03:15.239> number<00:03:15.519> of<00:03:15.840> ways<00:03:16.519> we<00:03:16.640> can
entropy is the number of ways we can
entropy is the number of ways we can
rearrange<00:03:17.519> the<00:03:17.640> constituents<00:03:18.200> of<00:03:18.280> a<00:03:18.440> system
rearrange the constituents of a system
rearrange the constituents of a system
so<00:03:18.879> that<00:03:19.000> you<00:03:19.120> don't<00:03:19.360> notice<00:03:20.239> so<00:03:20.400> that
so that you don't notice so that
so that you don't notice so that
macroscopically<00:03:21.519> it<00:03:21.680> looks<00:03:21.920> the<00:03:22.040> same<00:03:22.280> if<00:03:22.360> you
macroscopically it looks the same if you
macroscopically it looks the same if you
have<00:03:22.560> the<00:03:22.640> air<00:03:22.879> in<00:03:23.040> this<00:03:23.200> room<00:03:23.720> you<00:03:23.840> don't
have the air in this room you don't
have the air in this room you don't
notice<00:03:24.640> each<00:03:24.920> individual<00:03:25.599> atom<00:03:26.440> a<00:03:26.560> low
notice each individual atom a low
notice each individual atom a low
entropy<00:03:27.280> configuration<00:03:27.879> is<00:03:28.000> one<00:03:28.159> in<00:03:28.280> which
entropy configuration is one in which
entropy configuration is one in which
there's<00:03:28.640> only<00:03:28.879> a<00:03:29.000> few<00:03:29.239> Arrangements<00:03:29.959> that
there's only a few Arrangements that
there's only a few Arrangements that
look<00:03:30.319> that<00:03:30.480> way<00:03:30.920> a<00:03:31.080> high<00:03:31.280> entropy<00:03:31.680> Arrangement
look that way a high entropy Arrangement
look that way a high entropy Arrangement
is<00:03:32.159> one<00:03:32.319> that<00:03:32.480> there<00:03:32.560> are<00:03:32.799> many<00:03:33.360> Arrangements
is one that there are many Arrangements
is one that there are many Arrangements
that<00:03:34.040> look<00:03:34.319> that<00:03:34.480> way<00:03:35.080> this<00:03:35.200> is<00:03:35.319> a<00:03:35.599> crucially
that look that way this is a crucially
that look that way this is a crucially
important<00:03:36.480> Insight<00:03:36.879> because<00:03:37.040> it<00:03:37.159> helps<00:03:37.400> us
important Insight because it helps us
important Insight because it helps us
explain<00:03:38.159> the<00:03:38.360> second<00:03:38.760> law<00:03:39.040> of<00:03:39.400> Thermodynamics
explain the second law of Thermodynamics
explain the second law of Thermodynamics
the<00:03:40.560> law<00:03:40.760> that<00:03:40.879> says<00:03:41.040> that<00:03:41.200> entropy<00:03:41.760> increases
the law that says that entropy increases
the law that says that entropy increases
in<00:03:42.680> the<00:03:42.840> universe<00:03:43.760> or<00:03:44.000> in<00:03:44.159> some<00:03:44.360> isolated<00:03:44.799> bit
in the universe or in some isolated bit
in the universe or in some isolated bit
of<00:03:45.080> the<00:03:45.200> universe<00:03:46.000> the<00:03:46.159> reason<00:03:46.560> why<00:03:46.959> entropy
of the universe the reason why entropy
of the universe the reason why entropy
increases<00:03:47.840> is<00:03:48.000> simply<00:03:48.360> because<00:03:48.640> there<00:03:48.720> are
increases is simply because there are
increases is simply because there are
many<00:03:49.360> more<00:03:49.799> ways<00:03:50.599> to<00:03:50.799> be<00:03:51.080> high<00:03:51.280> entropy<00:03:51.760> than
many more ways to be high entropy than
many more ways to be high entropy than
to<00:03:51.959> be<00:03:52.120> low<00:03:52.360> entropy<00:03:53.319> that's<00:03:53.640> a<00:03:53.840> wonderful
to be low entropy that's a wonderful
to be low entropy that's a wonderful
Insight<00:03:54.920> but<00:03:55.040> it<00:03:55.159> leaves<00:03:55.599> something<00:03:55.959> out<00:03:56.840> uh
Insight but it leaves something out uh
Insight but it leaves something out uh
this<00:03:57.120> Insight<00:03:57.439> that<00:03:57.560> entropy<00:03:57.959> increases<00:03:58.480> by
this Insight that entropy increases by
this Insight that entropy increases by
the<00:03:58.720> way<00:03:59.040> is<00:03:59.239> what's<00:03:59.680> behind<00:04:00.079> what<00:04:00.200> we<00:04:00.400> call
the way is what's behind what we call
the way is what's behind what we call
the<00:04:00.799> arrow<00:04:01.120> of<00:04:01.360> time<00:04:02.079> the<00:04:02.280> difference<00:04:02.640> between
the arrow of time the difference between
the arrow of time the difference between
the<00:04:03.120> past<00:04:03.319> and<00:04:03.439> the<00:04:03.560> future<00:04:04.040> every<00:04:04.360> difference
the past and the future every difference
the past and the future every difference
that<00:04:04.879> there<00:04:05.159> is<00:04:06.159> between<00:04:06.519> the<00:04:06.720> past<00:04:06.920> and<00:04:07.040> the
that there is between the past and the
that there is between the past and the
future<00:04:07.640> is<00:04:07.799> because<00:04:08.120> entropy<00:04:08.560> is<00:04:08.680> increasing
future is because entropy is increasing
future is because entropy is increasing
the<00:04:09.799> fact<00:04:09.959> that<00:04:10.040> you<00:04:10.120> can<00:04:10.319> remember<00:04:11.000> the<00:04:11.200> past
the fact that you can remember the past
the fact that you can remember the past
but<00:04:11.599> not<00:04:11.760> the<00:04:11.879> future<00:04:12.599> the<00:04:12.760> fact<00:04:12.920> that<00:04:13.040> you<00:04:13.360> are
but not the future the fact that you are
but not the future the fact that you are
born<00:04:14.239> and<00:04:14.439> then<00:04:14.599> you<00:04:14.799> live<00:04:15.159> and<00:04:15.319> then<00:04:15.439> you<00:04:15.680> die
born and then you live and then you die
born and then you live and then you die
always<00:04:16.519> in<00:04:16.720> that<00:04:16.880> order<00:04:17.600> that's<00:04:17.799> because
always in that order that's because
always in that order that's because
entropy<00:04:18.519> is<00:04:18.680> increasing<00:04:19.600> boltzman<00:04:20.199> explained
entropy is increasing boltzman explained
entropy is increasing boltzman explained
that<00:04:20.799> if<00:04:20.919> you<00:04:21.160> start<00:04:21.479> with<00:04:21.680> low<00:04:21.959> entropy<00:04:22.400> it's
that if you start with low entropy it's
that if you start with low entropy it's
very<00:04:22.800> natural<00:04:23.080> for<00:04:23.240> it<00:04:23.320> to<00:04:23.440> increase<00:04:23.919> because
very natural for it to increase because
very natural for it to increase because
there's<00:04:24.320> more<00:04:24.600> ways<00:04:24.919> to<00:04:25.120> be<00:04:25.720> high<00:04:25.960> entropy
there's more ways to be high entropy
there's more ways to be high entropy
what<00:04:27.120> he<00:04:27.320> didn't<00:04:27.960> explain<00:04:28.520> was<00:04:28.840> why<00:04:29.080> the
what he didn't explain was why the
what he didn't explain was why the
entropy<00:04:30.000> was<00:04:30.280> ever<00:04:30.600> low<00:04:30.960> in<00:04:31.120> the<00:04:31.280> first<00:04:31.600> place
entropy was ever low in the first place
entropy was ever low in the first place
the<00:04:32.479> fact<00:04:32.639> that<00:04:32.759> the<00:04:32.880> entropy<00:04:33.240> of<00:04:33.320> the
the fact that the entropy of the
the fact that the entropy of the
universe<00:04:33.840> was<00:04:34.000> low<00:04:34.199> is<00:04:34.320> a<00:04:34.520> reflection<00:04:34.960> of<00:04:35.120> the
universe was low is a reflection of the
universe was low is a reflection of the
fact<00:04:35.440> that<00:04:35.560> the<00:04:35.680> early<00:04:36.039> Universe<00:04:36.479> was<00:04:36.720> very
fact that the early Universe was very
fact that the early Universe was very
very<00:04:37.600> smooth<00:04:38.000> we'd<00:04:38.280> like<00:04:38.440> to<00:04:39.000> understand<00:04:39.280> that
very smooth we'd like to understand that
very smooth we'd like to understand that
that's<00:04:39.680> our<00:04:39.960> job<00:04:40.199> as<00:04:40.840> cosmologists
that's our job as cosmologists
that's our job as cosmologists
unfortunately<00:04:42.520> it's<00:04:42.840> actually<00:04:43.240> not<00:04:43.520> a
unfortunately it's actually not a
unfortunately it's actually not a
problem<00:04:44.280> that<00:04:44.440> we've<00:04:44.600> been<00:04:44.759> giving<00:04:45.080> enough
problem that we've been giving enough
problem that we've been giving enough
attention<00:04:45.720> to<00:04:46.000> it's<00:04:46.160> not<00:04:46.600> one<00:04:46.720> of<00:04:46.840> the<00:04:46.960> first
attention to it's not one of the first
attention to it's not one of the first
things<00:04:47.479> people<00:04:47.720> would<00:04:47.880> say<00:04:48.120> if<00:04:48.199> you<00:04:48.360> asked<00:04:48.560> a
things people would say if you asked a
things people would say if you asked a
modern<00:04:48.960> cosmologist<00:04:49.600> what<00:04:49.680> are<00:04:49.840> the<00:04:50.000> problems
modern cosmologist what are the problems
modern cosmologist what are the problems
we're<00:04:50.479> trying<00:04:50.720> to<00:04:50.919> address<00:04:51.800> one<00:04:51.919> of<00:04:52.080> the
we're trying to address one of the
we're trying to address one of the
people<00:04:52.400> who<00:04:52.600> did<00:04:53.080> understand<00:04:53.240> that<00:04:53.400> this<00:04:53.520> was
people who did understand that this was
people who did understand that this was
a<00:04:53.840> problem<00:04:54.120> was<00:04:54.280> Richard<00:04:54.600> feeman<00:04:55.520> 50<00:04:55.880> years
a problem was Richard feeman 50 years
a problem was Richard feeman 50 years
ago<00:04:56.360> he<00:04:56.520> gave<00:04:56.639> a<00:04:56.800> series<00:04:57.080> of<00:04:57.240> a<00:04:57.360> bunch<00:04:57.520> of
ago he gave a series of a bunch of
ago he gave a series of a bunch of
different<00:04:57.919> lectures<00:04:58.600> gave<00:04:58.840> the<00:04:59.120> popular
different lectures gave the popular
different lectures gave the popular
lectures<00:04:59.960> that<00:05:00.120> became<00:05:00.360> the<00:05:00.479> character
lectures that became the character
lectures that became the character
physical<00:05:01.280> law<00:05:01.800> he<00:05:01.960> gave<00:05:02.160> lectures<00:05:02.440> to<00:05:02.600> Caltech
physical law he gave lectures to Caltech
physical law he gave lectures to Caltech
undergrads<00:05:03.639> that<00:05:03.759> became<00:05:03.960> the<00:05:04.080> F<00:05:04.400> lectures<00:05:04.720> on
undergrads that became the F lectures on
undergrads that became the F lectures on
physics<00:05:05.199> he<00:05:05.320> gave<00:05:05.479> lectures<00:05:05.800> to<00:05:05.919> Caltech
physics he gave lectures to Caltech
physics he gave lectures to Caltech
graduate<00:05:06.800> students<00:05:07.160> that<00:05:07.240> became<00:05:07.520> the<00:05:07.600> F
graduate students that became the F
graduate students that became the F
lectures<00:05:08.120> on<00:05:08.600> gravitation<00:05:09.600> in<00:05:09.880> every<00:05:10.120> one<00:05:10.280> of
lectures on gravitation in every one of
lectures on gravitation in every one of
these<00:05:10.639> books<00:05:11.000> every<00:05:11.160> one<00:05:11.280> of<00:05:11.360> these<00:05:11.520> sets<00:05:11.680> of
these books every one of these sets of
these books every one of these sets of
lectures<00:05:12.320> he<00:05:12.560> emphasized<00:05:13.400> this<00:05:13.639> puzzle<00:05:14.639> why
lectures he emphasized this puzzle why
lectures he emphasized this puzzle why
did<00:05:15.199> the<00:05:15.320> early<00:05:15.759> Universe<00:05:16.280> have<00:05:16.520> such<00:05:16.639> a<00:05:16.800> small
did the early Universe have such a small
did the early Universe have such a small
entropy<00:05:17.720> so<00:05:17.880> he<00:05:18.000> says<00:05:18.400> I'm<00:05:18.479> not<00:05:18.600> going<00:05:18.680> to<00:05:18.759> do
entropy so he says I'm not going to do
entropy so he says I'm not going to do
the<00:05:19.120> accent<00:05:20.120> he<00:05:20.240> says<00:05:20.720> for<00:05:20.960> some<00:05:21.280> reason<00:05:21.759> the
the accent he says for some reason the
the accent he says for some reason the
universe<00:05:22.240> at<00:05:22.400> one<00:05:22.600> time<00:05:22.840> had<00:05:22.960> a<00:05:23.199> very<00:05:23.520> low
universe at one time had a very low
universe at one time had a very low
entropy<00:05:24.280> for<00:05:24.479> its<00:05:24.639> energy<00:05:25.080> content<00:05:25.560> and<00:05:25.759> since
entropy for its energy content and since
entropy for its energy content and since
then<00:05:26.199> the<00:05:26.280> entropy<00:05:26.680> has<00:05:26.919> increased<00:05:27.919> the<00:05:28.039> arrow
then the entropy has increased the arrow
then the entropy has increased the arrow
of<00:05:28.520> time<00:05:28.800> cannot<00:05:29.120> be<00:05:29.560> completely<00:05:29.960> understood
of time cannot be completely understood
of time cannot be completely understood
until<00:05:31.199> the<00:05:31.360> mystery<00:05:31.720> of<00:05:31.840> the<00:05:32.039> beginnings<00:05:32.520> of
until the mystery of the beginnings of
until the mystery of the beginnings of
the<00:05:32.800> history<00:05:33.080> of<00:05:33.199> the<00:05:33.319> universe<00:05:33.880> are<00:05:34.080> reduced
the history of the universe are reduced
the history of the universe are reduced
still<00:05:34.960> further<00:05:35.720> from<00:05:36.000> speculation<00:05:36.639> to
still further from speculation to
still further from speculation to
understanding<00:05:38.360> so<00:05:38.560> that's<00:05:38.759> our<00:05:39.039> job<00:05:39.319> we<00:05:39.400> want
understanding so that's our job we want
understanding so that's our job we want
to<00:05:39.720> know<00:05:40.120> this<00:05:40.240> is<00:05:40.440> 50<00:05:40.759> years<00:05:40.960> ago<00:05:41.280> surely
to know this is 50 years ago surely
to know this is 50 years ago surely
you're<00:05:41.840> thinking<00:05:42.240> we<00:05:42.400> figured<00:05:42.680> it<00:05:42.759> out<00:05:43.000> by<00:05:43.199> now
you're thinking we figured it out by now
you're thinking we figured it out by now
uh<00:05:44.240> it's<00:05:44.440> not<00:05:44.759> true<00:05:45.000> that<00:05:45.120> we<00:05:45.240> figured<00:05:45.479> it<00:05:45.600> out
uh it's not true that we figured it out
uh it's not true that we figured it out
by<00:05:45.960> now<00:05:46.360> the<00:05:46.440> reason<00:05:46.720> the<00:05:46.880> problem<00:05:47.080> has<00:05:47.240> gotten
by now the reason the problem has gotten
by now the reason the problem has gotten
worse<00:05:48.479> rather<00:05:48.720> than<00:05:48.960> better<00:05:49.720> is<00:05:49.919> because<00:05:50.240> in
worse rather than better is because in
worse rather than better is because in
1998<00:05:51.199> we<00:05:51.360> learned<00:05:51.840> something<00:05:52.199> crucial<00:05:52.759> about
1998 we learned something crucial about
1998 we learned something crucial about
the<00:05:53.080> universe<00:05:53.560> that<00:05:53.639> we<00:05:53.759> didn't<00:05:53.960> know<00:05:54.199> before
the universe that we didn't know before
the universe that we didn't know before
we<00:05:54.840> learned<00:05:55.120> that<00:05:55.240> it's<00:05:55.639> accelerating<00:05:56.639> the
we learned that it's accelerating the
we learned that it's accelerating the
universe<00:05:57.080> is<00:05:57.240> not<00:05:57.400> only<00:05:57.680> expanding<00:05:58.160> if<00:05:58.280> you
universe is not only expanding if you
universe is not only expanding if you
look<00:05:58.479> at<00:05:58.600> that<00:05:58.759> Galaxy<00:05:59.120> it's<00:05:59.199> moving<00:05:59.440> moving
look at that Galaxy it's moving moving
look at that Galaxy it's moving moving
away<00:06:00.440> if<00:06:00.520> you<00:06:00.720> come<00:06:00.960> back<00:06:01.160> a<00:06:01.280> billion<00:06:01.639> years
away if you come back a billion years
away if you come back a billion years
later<00:06:02.160> and<00:06:02.280> look<00:06:02.440> at<00:06:02.520> it<00:06:02.800> again<00:06:03.120> it<00:06:03.199> will<00:06:03.319> be
later and look at it again it will be
later and look at it again it will be
moving<00:06:03.800> away<00:06:04.560> faster<00:06:05.560> individual<00:06:06.120> galaxies
moving away faster individual galaxies
moving away faster individual galaxies
are<00:06:06.759> speeding<00:06:07.199> away<00:06:07.560> from<00:06:07.720> us<00:06:07.960> faster<00:06:08.240> and
are speeding away from us faster and
are speeding away from us faster and
faster<00:06:08.720> so<00:06:08.840> we<00:06:08.960> say<00:06:09.199> the<00:06:09.319> universe<00:06:09.720> is
faster so we say the universe is
faster so we say the universe is
accelerating<00:06:11.360> unlike<00:06:11.680> the<00:06:11.759> low<00:06:12.000> entropy<00:06:12.360> of
accelerating unlike the low entropy of
accelerating unlike the low entropy of
the<00:06:12.479> early<00:06:12.720> Universe<00:06:13.120> even<00:06:13.280> though<00:06:13.400> we<00:06:13.560> don't
the early Universe even though we don't
the early Universe even though we don't
know<00:06:13.960> the<00:06:14.160> answer<00:06:14.440> for<00:06:14.680> this<00:06:14.919> we<00:06:15.039> at<00:06:15.120> least
know the answer for this we at least
know the answer for this we at least
have<00:06:15.479> a<00:06:15.680> good<00:06:15.880> theory<00:06:16.840> that<00:06:17.080> can<00:06:17.319> explain<00:06:17.599> it
have a good theory that can explain it
have a good theory that can explain it
if<00:06:17.919> that<00:06:18.039> theory<00:06:18.319> is<00:06:18.479> right<00:06:18.680> and<00:06:18.800> that's<00:06:18.919> the
if that theory is right and that's the
if that theory is right and that's the
theory<00:06:19.319> of<00:06:19.479> dark<00:06:19.759> energy<00:06:20.720> it's<00:06:20.919> just<00:06:21.120> the<00:06:21.280> idea
theory of dark energy it's just the idea
theory of dark energy it's just the idea
that<00:06:21.840> empty<00:06:22.280> space<00:06:22.840> itself<00:06:23.720> has<00:06:23.919> energy<00:06:24.319> in
that empty space itself has energy in
that empty space itself has energy in
every<00:06:24.680> little<00:06:24.919> cubic<00:06:25.199> centimeter<00:06:25.680> of<00:06:25.880> space
every little cubic centimeter of space
every little cubic centimeter of space
whether<00:06:26.759> or<00:06:26.880> not<00:06:27.080> there's<00:06:27.440> stuff<00:06:28.120> whether<00:06:28.280> or
whether or not there's stuff whether or
whether or not there's stuff whether or
not<00:06:28.520> there's<00:06:28.759> particles<00:06:29.479> matter<00:06:29.759> radiation
not there's particles matter radiation
not there's particles matter radiation
or<00:06:30.360> whatever<00:06:30.680> there<00:06:30.800> is<00:06:31.039> still<00:06:31.560> energy<00:06:32.400> even
or whatever there is still energy even
or whatever there is still energy even
in<00:06:32.759> the<00:06:32.919> space<00:06:33.240> itself<00:06:34.199> and<00:06:34.360> this<00:06:34.520> energy
in the space itself and this energy
in the space itself and this energy
according<00:06:35.199> to<00:06:35.360> Einstein<00:06:36.039> exerts<00:06:36.440> a<00:06:36.680> push<00:06:37.039> on
according to Einstein exerts a push on
according to Einstein exerts a push on
the<00:06:37.360> universe<00:06:38.319> it<00:06:38.599> is<00:06:38.680> a<00:06:38.919> Perpetual<00:06:39.599> impulse
the universe it is a Perpetual impulse
the universe it is a Perpetual impulse
that<00:06:40.360> pushes<00:06:40.759> galaxies<00:06:41.240> apart<00:06:41.560> from<00:06:41.720> each
that pushes galaxies apart from each
that pushes galaxies apart from each
other<00:06:42.639> because<00:06:43.639> Dark<00:06:43.960> Energy<00:06:44.520> unlike<00:06:44.919> matter
other because Dark Energy unlike matter
other because Dark Energy unlike matter
radiation<00:06:46.120> does<00:06:46.319> not<00:06:46.599> dilute<00:06:47.039> away<00:06:47.840> as<00:06:47.960> the
radiation does not dilute away as the
radiation does not dilute away as the
universe<00:06:48.560> expands<00:06:49.080> the<00:06:49.199> amount<00:06:49.440> of<00:06:49.599> energy<00:06:49.919> in
universe expands the amount of energy in
universe expands the amount of energy in
each<00:06:50.280> cubic<00:06:50.560> centimeter<00:06:51.280> Remains<00:06:51.680> the<00:06:51.840> Same
each cubic centimeter Remains the Same
each cubic centimeter Remains the Same
even<00:06:52.840> as<00:06:52.960> the<00:06:53.080> universe<00:06:53.560> gets<00:06:53.800> bigger<00:06:54.080> and
even as the universe gets bigger and
even as the universe gets bigger and
bigger<00:06:55.160> this<00:06:55.319> has<00:06:55.599> crucial<00:06:56.400> implications<00:06:57.400> for
bigger this has crucial implications for
bigger this has crucial implications for
what<00:06:57.800> the<00:06:57.879> universe<00:06:58.280> is<00:06:58.400> going<00:06:58.599> to<00:06:58.759> do<00:06:59.000> in<00:06:59.120> the
what the universe is going to do in the
what the universe is going to do in the
future<00:07:00.080> for<00:07:00.280> one<00:07:00.520> thing<00:07:01.000> the<00:07:01.120> universe<00:07:01.520> will
future for one thing the universe will
future for one thing the universe will
expand<00:07:02.120> forever<00:07:02.720> back<00:07:02.879> when<00:07:03.039> I<00:07:03.199> was<00:07:03.360> your<00:07:03.599> age
expand forever back when I was your age
expand forever back when I was your age
we<00:07:04.400> didn't<00:07:04.639> know<00:07:05.199> what<00:07:05.319> the<00:07:05.440> universe<00:07:05.759> was
we didn't know what the universe was
we didn't know what the universe was
going<00:07:06.000> to<00:07:06.120> do<00:07:06.319> we<00:07:06.479> thought<00:07:06.680> some<00:07:06.840> people
going to do we thought some people
going to do we thought some people
thought<00:07:07.240> that<00:07:07.360> the<00:07:07.440> Universe<00:07:07.759> would
thought that the Universe would
thought that the Universe would
recollapse<00:07:08.440> in<00:07:08.800> the<00:07:08.919> future<00:07:09.319> Einstein<00:07:09.960> was
recollapse in the future Einstein was
recollapse in the future Einstein was
fond<00:07:10.400> of<00:07:10.599> this<00:07:10.759> idea<00:07:11.599> but<00:07:11.800> if<00:07:12.000> there's<00:07:12.360> dark
fond of this idea but if there's dark
fond of this idea but if there's dark
energy<00:07:12.960> and<00:07:13.080> the<00:07:13.199> dark<00:07:13.400> energy<00:07:13.759> does<00:07:13.960> not<00:07:14.199> go
energy and the dark energy does not go
energy and the dark energy does not go
away<00:07:15.080> the<00:07:15.199> universe<00:07:15.560> is<00:07:15.680> just<00:07:15.759> going<00:07:15.879> to<00:07:16.039> keep
away the universe is just going to keep
away the universe is just going to keep
expanding<00:07:16.800> forever<00:07:17.160> and<00:07:17.280> ever<00:07:17.479> and<00:07:17.639> ever<00:07:18.160> 14
expanding forever and ever and ever 14
expanding forever and ever and ever 14
billion<00:07:19.039> years<00:07:19.240> in<00:07:19.360> the<00:07:19.520> past<00:07:20.000> 100<00:07:20.160> billion
billion years in the past 100 billion
billion years in the past 100 billion
dog<00:07:20.759> years<00:07:21.440> but<00:07:21.599> an<00:07:21.800> infinite<00:07:22.199> number<00:07:22.440> of
dog years but an infinite number of
dog years but an infinite number of
years<00:07:23.000> into<00:07:23.360> the<00:07:23.759> future<00:07:24.759> meanwhile<00:07:25.599> for<00:07:25.759> all
years into the future meanwhile for all
years into the future meanwhile for all
intents<00:07:26.240> and<00:07:26.440> purposes<00:07:27.280> space<00:07:28.000> looks<00:07:28.440> finite
intents and purposes space looks finite
intents and purposes space looks finite
to<00:07:29.080> us<00:07:29.800> space<00:07:30.160> may<00:07:30.360> be<00:07:30.720> finite<00:07:31.080> or<00:07:31.240> infinite
to us space may be finite or infinite
to us space may be finite or infinite
but<00:07:32.120> because<00:07:32.360> the<00:07:32.479> universe<00:07:32.840> is<00:07:33.080> accelerating
but because the universe is accelerating
but because the universe is accelerating
there<00:07:33.840> are<00:07:34.039> parts<00:07:34.240> of<00:07:34.400> it<00:07:34.599> we<00:07:34.800> cannot<00:07:35.199> see<00:07:35.520> and
there are parts of it we cannot see and
there are parts of it we cannot see and
never<00:07:36.000> will<00:07:36.560> see<00:07:37.240> there's<00:07:37.440> a<00:07:37.560> finite<00:07:37.919> region
never will see there's a finite region
never will see there's a finite region
of<00:07:38.440> space<00:07:38.680> that<00:07:38.800> we<00:07:38.919> have<00:07:39.160> access<00:07:39.479> to
of space that we have access to
of space that we have access to
surrounded<00:07:40.199> by<00:07:40.319> a<00:07:40.520> horizon<00:07:41.360> so<00:07:41.560> even<00:07:41.759> though
surrounded by a horizon so even though
surrounded by a horizon so even though
time<00:07:42.280> goes<00:07:42.479> on<00:07:42.680> forever<00:07:43.479> space<00:07:43.879> is<00:07:44.039> limited<00:07:44.400> to
time goes on forever space is limited to
time goes on forever space is limited to
us<00:07:45.840> finally<00:07:46.840> empty<00:07:47.319> space<00:07:47.680> has<00:07:47.800> a<00:07:48.080> temperature
us finally empty space has a temperature
us finally empty space has a temperature
in<00:07:49.039> the<00:07:49.159> 1970s<00:07:49.919> Steven<00:07:50.240> Hawking<00:07:50.639> told<00:07:50.840> us<00:07:51.000> that
in the 1970s Steven Hawking told us that
in the 1970s Steven Hawking told us that
a<00:07:51.280> black<00:07:51.599> hole<00:07:52.199> even<00:07:52.400> though<00:07:52.520> you<00:07:52.639> think<00:07:52.800> it's
a black hole even though you think it's
a black hole even though you think it's
black<00:07:53.360> it<00:07:53.520> actually<00:07:53.800> emits<00:07:54.159> radiation<00:07:54.720> when
black it actually emits radiation when
black it actually emits radiation when
you<00:07:54.960> take<00:07:55.159> into<00:07:55.440> account<00:07:56.000> quantum<00:07:56.400> mechanics
you take into account quantum mechanics
you take into account quantum mechanics
the<00:07:57.039> curvature<00:07:57.520> of<00:07:57.680> SpaceTime<00:07:58.199> around<00:07:58.479> the
the curvature of SpaceTime around the
the curvature of SpaceTime around the
black<00:07:58.840> hole<00:07:59.520> brings<00:07:59.879> to<00:08:00.199> life<00:08:00.599> the<00:08:00.720> quantum
black hole brings to life the quantum
black hole brings to life the quantum
mechanical<00:08:01.520> fluctuation<00:08:02.520> and<00:08:02.639> the<00:08:02.759> black
mechanical fluctuation and the black
mechanical fluctuation and the black
hole<00:08:03.599> radiates<00:08:04.599> a<00:08:04.800> precisely<00:08:05.240> similar
hole radiates a precisely similar
hole radiates a precisely similar
calculation<00:08:06.240> by<00:08:06.360> Hawking<00:08:06.720> and<00:08:06.840> Gary<00:08:07.080> Gibbons
calculation by Hawking and Gary Gibbons
calculation by Hawking and Gary Gibbons
show<00:08:08.080> that<00:08:08.199> if<00:08:08.280> you<00:08:08.440> have<00:08:08.680> dark<00:08:09.080> energy<00:08:09.639> in
show that if you have dark energy in
show that if you have dark energy in
empty<00:08:10.240> space<00:08:11.120> then<00:08:11.280> the<00:08:11.400> whole<00:08:11.639> universe
empty space then the whole universe
empty space then the whole universe
radiates<00:08:13.759> the<00:08:14.199> energy<00:08:14.520> of<00:08:14.639> empty<00:08:14.960> space
radiates the energy of empty space
radiates the energy of empty space
brings<00:08:15.680> to<00:08:15.879> life<00:08:16.159> Quantum<00:08:16.560> fluctuations<00:08:17.319> and
brings to life Quantum fluctuations and
brings to life Quantum fluctuations and
so<00:08:17.639> even<00:08:17.800> though<00:08:17.960> the<00:08:18.039> universe<00:08:18.400> will<00:08:18.639> last
so even though the universe will last
so even though the universe will last
forever<00:08:19.960> and<00:08:20.120> ordinary<00:08:20.560> matter<00:08:20.800> and
forever and ordinary matter and
forever and ordinary matter and
radiation<00:08:21.319> will<00:08:21.520> dilute<00:08:21.960> away<00:08:22.280> there<00:08:22.400> will
radiation will dilute away there will
radiation will dilute away there will
always<00:08:22.960> be<00:08:23.319> some<00:08:23.840> radiation<00:08:24.840> some<00:08:25.280> thermal
always be some radiation some thermal
always be some radiation some thermal
fluctuations<00:08:26.960> even<00:08:27.159> in<00:08:27.360> empty<00:08:27.720> space<00:08:28.639> so<00:08:28.800> what
fluctuations even in empty space so what
fluctuations even in empty space so what
this<00:08:29.000> means<00:08:29.479> is<00:08:29.680> that<00:08:29.879> the<00:08:30.080> universe<00:08:31.000> is<00:08:31.199> like
this means is that the universe is like
this means is that the universe is like
a<00:08:31.560> box<00:08:31.759> of<00:08:32.000> gas<00:08:32.719> that<00:08:32.959> lasts<00:08:33.479> forever<00:08:34.479> well
a box of gas that lasts forever well
a box of gas that lasts forever well
what<00:08:34.719> is<00:08:34.919> the<00:08:35.279> implication<00:08:35.800> of<00:08:36.039> that<00:08:36.800> that
what is the implication of that that
what is the implication of that that
implication<00:08:37.479> was<00:08:37.599> studied<00:08:37.919> by<00:08:38.039> boltzman<00:08:38.599> back
implication was studied by boltzman back
implication was studied by boltzman back
in<00:08:38.839> the<00:08:38.959> 19th<00:08:39.360> century<00:08:39.760> he<00:08:39.880> said<00:08:40.440> well<00:08:41.440> entropy
in the 19th century he said well entropy
in the 19th century he said well entropy
increases<00:08:43.320> because<00:08:43.640> there<00:08:43.719> are<00:08:43.880> many<00:08:44.120> many
increases because there are many many
increases because there are many many
more<00:08:44.519> ways<00:08:44.720> for<00:08:44.880> the<00:08:44.959> universe<00:08:45.360> to<00:08:45.480> be<00:08:45.720> high
more ways for the universe to be high
more ways for the universe to be high
entropy<00:08:46.440> rather<00:08:46.640> than<00:08:46.800> low<00:08:47.040> entropy<00:08:48.000> but
entropy rather than low entropy but
entropy rather than low entropy but
that's<00:08:48.279> a<00:08:48.760> probabilistic<00:08:49.760> statement<00:08:50.560> it<00:08:50.680> will
that's a probabilistic statement it will
that's a probabilistic statement it will
probably<00:08:51.640> increase<00:08:52.200> and<00:08:52.320> the<00:08:52.440> probability<00:08:52.920> is
probably increase and the probability is
probably increase and the probability is
enormously<00:08:54.040> huge<00:08:54.320> it's<00:08:54.440> not<00:08:54.560> something<00:08:54.760> you
enormously huge it's not something you
enormously huge it's not something you
have<00:08:54.959> to<00:08:55.080> worry<00:08:55.360> about<00:08:55.920> the<00:08:56.240> air<00:08:56.480> in<00:08:56.640> this<00:08:56.800> room
have to worry about the air in this room
have to worry about the air in this room
all<00:08:57.360> gathering<00:08:58.000> over<00:08:58.279> one<00:08:58.720> uh<00:08:58.839> part<00:08:59.000> of<00:08:59.240> the
all gathering over one uh part of the
all gathering over one uh part of the
room<00:08:59.600> and<00:08:59.839> and<00:09:00.040> suffocating<00:09:00.680> us<00:09:01.160> it's<00:09:01.399> very
room and and suffocating us it's very
room and and suffocating us it's very
very<00:09:02.279> unlikely<00:09:03.279> except<00:09:03.880> if<00:09:04.000> they<00:09:04.120> locked<00:09:04.399> the
very unlikely except if they locked the
very unlikely except if they locked the
doors<00:09:04.720> and<00:09:04.920> kept<00:09:05.120> us<00:09:05.320> here<00:09:05.640> literally<00:09:06.399> forever
doors and kept us here literally forever
doors and kept us here literally forever
that<00:09:07.560> would<00:09:07.839> happen<00:09:08.839> everything<00:09:09.320> that<00:09:09.480> is
that would happen everything that is
that would happen everything that is
allowed<00:09:10.120> every<00:09:10.360> configuration<00:09:11.000> that<00:09:11.120> is
allowed every configuration that is
allowed every configuration that is
allowed<00:09:11.519> to<00:09:11.640> be<00:09:11.800> attained<00:09:12.680> by<00:09:12.800> the<00:09:12.959> molecules
allowed to be attained by the molecules
allowed to be attained by the molecules
in<00:09:13.560> this<00:09:13.720> room<00:09:14.000> would<00:09:14.200> eventually<00:09:14.600> be
in this room would eventually be
in this room would eventually be
obtained<00:09:15.360> so<00:09:15.519> boltzman<00:09:15.959> says<00:09:16.240> look<00:09:16.720> you<00:09:16.880> could
obtained so boltzman says look you could
obtained so boltzman says look you could
start<00:09:17.399> with<00:09:17.519> a<00:09:17.920> universe<00:09:18.920> that<00:09:19.000> was<00:09:19.120> in
start with a universe that was in
start with a universe that was in
thermal<00:09:19.600> equilibrium<00:09:20.399> he<00:09:20.519> didn't<00:09:20.720> know<00:09:20.880> about
thermal equilibrium he didn't know about
thermal equilibrium he didn't know about
the<00:09:21.200> Big<00:09:21.360> Bang<00:09:21.600> he<00:09:21.720> didn't<00:09:21.880> know<00:09:22.000> about<00:09:22.160> the
the Big Bang he didn't know about the
the Big Bang he didn't know about the
expansion<00:09:22.600> of<00:09:22.720> the<00:09:22.800> universe<00:09:23.240> he<00:09:23.399> thought
expansion of the universe he thought
expansion of the universe he thought
that<00:09:24.120> space<00:09:24.399> and<00:09:24.640> time<00:09:24.880> were<00:09:25.120> explained<00:09:25.600> by
that space and time were explained by
that space and time were explained by
Isaac<00:09:26.120> Newton<00:09:26.640> they<00:09:26.720> were<00:09:27.000> absolute<00:09:27.440> they
Isaac Newton they were absolute they
Isaac Newton they were absolute they
just<00:09:27.720> stuck<00:09:28.000> there<00:09:28.160> forever<00:09:28.920> so<00:09:29.200> so<00:09:29.320> his<00:09:29.440> idea
just stuck there forever so so his idea
just stuck there forever so so his idea
of<00:09:29.760> a<00:09:30.000> natural<00:09:30.440> Universe<00:09:31.279> was<00:09:31.440> one<00:09:31.600> in<00:09:31.720> which
of a natural Universe was one in which
of a natural Universe was one in which
the<00:09:32.000> air<00:09:32.200> molecules<00:09:32.640> were<00:09:32.839> just<00:09:32.959> spread<00:09:33.240> out
the air molecules were just spread out
the air molecules were just spread out
evenly<00:09:33.959> everywhere<00:09:34.600> the<00:09:34.880> everything
evenly everywhere the everything
evenly everywhere the everything
molecules<00:09:36.279> but<00:09:36.399> if<00:09:36.519> you're<00:09:36.640> a<00:09:36.720> boltzman<00:09:37.160> you
molecules but if you're a boltzman you
molecules but if you're a boltzman you
know<00:09:37.360> that<00:09:37.440> if<00:09:37.560> you<00:09:37.720> wait<00:09:38.000> long<00:09:38.320> enough<00:09:39.040> the
know that if you wait long enough the
know that if you wait long enough the
random<00:09:39.680> fluctuations<00:09:40.399> of<00:09:40.640> those<00:09:40.839> molecules
random fluctuations of those molecules
random fluctuations of those molecules
will<00:09:41.800> occasionally<00:09:42.399> bring<00:09:42.640> them<00:09:42.839> into<00:09:43.360> lower
will occasionally bring them into lower
will occasionally bring them into lower
entropy<00:09:44.680> configurations<00:09:45.680> and<00:09:45.800> then<00:09:45.959> of
entropy configurations and then of
entropy configurations and then of
course<00:09:46.279> in<00:09:46.399> the<00:09:46.519> natural<00:09:46.839> course<00:09:47.079> of<00:09:47.240> things
course in the natural course of things
course in the natural course of things
they<00:09:47.959> will<00:09:48.200> expand<00:09:48.760> back<00:09:49.560> so<00:09:49.720> it's<00:09:49.839> not<00:09:50.000> that
they will expand back so it's not that
they will expand back so it's not that
entropy<00:09:50.640> must<00:09:51.000> always<00:09:51.320> increase<00:09:51.800> you<00:09:51.920> can<00:09:52.160> get
entropy must always increase you can get
entropy must always increase you can get
fluctuations<00:09:53.320> into<00:09:53.560> lower<00:09:53.959> entropy<00:09:54.880> more
fluctuations into lower entropy more
fluctuations into lower entropy more
organized
organized
organized
situations<00:09:58.040> well<00:09:58.200> if<00:09:58.360> that's<00:09:58.600> true<00:09:58.920> both<00:09:59.079> bman
situations well if that's true both bman
situations well if that's true both bman
then<00:09:59.680> goes<00:09:59.839> on<00:10:00.000> to<00:10:00.160> invent<00:10:00.519> two<00:10:00.839> very<00:10:01.079> modern
then goes on to invent two very modern
then goes on to invent two very modern
sounding<00:10:01.959> ideas<00:10:02.760> the<00:10:02.959> Multiverse<00:10:03.720> and<00:10:03.880> the
sounding ideas the Multiverse and the
sounding ideas the Multiverse and the
anthropic<00:10:04.720> principle<00:10:05.720> he<00:10:05.880> says<00:10:06.360> the<00:10:06.560> problem
anthropic principle he says the problem
anthropic principle he says the problem
with<00:10:07.000> thermal<00:10:07.320> equilibrium<00:10:07.839> is<00:10:07.920> that<00:10:08.040> we
with thermal equilibrium is that we
with thermal equilibrium is that we
can't<00:10:08.399> live<00:10:08.680> there<00:10:09.200> remember<00:10:09.640> life<00:10:09.920> itself
can't live there remember life itself
can't live there remember life itself
depends<00:10:11.240> on<00:10:11.360> the<00:10:11.480> Arrow<00:10:11.839> of<00:10:12.000> time<00:10:12.279> we<00:10:12.360> would
depends on the Arrow of time we would
depends on the Arrow of time we would
not<00:10:12.640> be<00:10:12.720> able<00:10:12.880> to<00:10:13.079> process<00:10:13.440> information
not be able to process information
not be able to process information
metabolize<00:10:15.079> walk<00:10:15.240> and<00:10:15.519> talk<00:10:16.120> if<00:10:16.279> we<00:10:16.480> lived<00:10:16.800> in
metabolize walk and talk if we lived in
metabolize walk and talk if we lived in
thermal<00:10:17.360> equilibrium<00:10:18.200> so<00:10:18.600> if<00:10:18.680> you<00:10:18.839> imagine<00:10:19.160> a
thermal equilibrium so if you imagine a
thermal equilibrium so if you imagine a
very<00:10:19.680> very<00:10:19.920> big<00:10:20.120> universe<00:10:20.600> an<00:10:20.760> infinitely<00:10:21.240> Big
very very big universe an infinitely Big
very very big universe an infinitely Big
Universe<00:10:22.279> with<00:10:22.519> randomly<00:10:23.079> bumping<00:10:23.320> into<00:10:23.519> each
Universe with randomly bumping into each
Universe with randomly bumping into each
other<00:10:24.000> particles<00:10:24.880> there<00:10:24.959> will<00:10:25.160> occasionally
other particles there will occasionally
other particles there will occasionally
be<00:10:25.800> small<00:10:26.200> fluctuations<00:10:26.839> in<00:10:26.959> the<00:10:27.040> lower
be small fluctuations in the lower
be small fluctuations in the lower
entropy<00:10:27.640> States<00:10:27.880> and<00:10:28.000> then<00:10:28.120> they<00:10:28.279> relax<00:10:28.800> back
entropy States and then they relax back
entropy States and then they relax back
but<00:10:29.560> there<00:10:29.680> will<00:10:29.880> also<00:10:30.079> be<00:10:30.279> large
but there will also be large
but there will also be large
fluctuations<00:10:31.640> occasionally<00:10:32.079> you<00:10:32.160> will<00:10:32.320> make
fluctuations occasionally you will make
fluctuations occasionally you will make
a<00:10:32.680> planet<00:10:33.680> or<00:10:33.839> a<00:10:34.079> star<00:10:34.800> or<00:10:35.000> a<00:10:35.240> Galaxy<00:10:36.079> or<00:10:36.240> a<00:10:36.399> 100
a planet or a star or a Galaxy or a 100
a planet or a star or a Galaxy or a 100
billion<00:10:37.639> galaxies<00:10:38.639> so<00:10:38.839> boltzman<00:10:39.399> says<00:10:40.079> we
billion galaxies so boltzman says we
billion galaxies so boltzman says we
will<00:10:40.480> only<00:10:40.920> live<00:10:41.399> in<00:10:41.480> the<00:10:41.639> part<00:10:41.800> of<00:10:41.920> the
will only live in the part of the
will only live in the part of the
Multiverse<00:10:42.920> in<00:10:43.040> the<00:10:43.160> part<00:10:43.320> of<00:10:43.440> this
Multiverse in the part of this
Multiverse in the part of this
infinitely<00:10:44.200> big<00:10:44.440> set<00:10:44.639> of<00:10:44.760> fluctuating
infinitely big set of fluctuating
infinitely big set of fluctuating
particles<00:10:46.240> where<00:10:46.480> life<00:10:46.680> is<00:10:46.959> possible<00:10:47.440> that's
particles where life is possible that's
particles where life is possible that's
the<00:10:47.760> regions<00:10:48.120> where<00:10:48.279> entropy<00:10:48.760> is<00:10:48.880> low<00:10:49.560> maybe
the regions where entropy is low maybe
the regions where entropy is low maybe
our<00:10:50.240> universe<00:10:50.800> is<00:10:51.000> just<00:10:51.200> one<00:10:51.320> of<00:10:51.519> those<00:10:51.680> things
our universe is just one of those things
our universe is just one of those things
that<00:10:52.200> happens<00:10:52.800> from<00:10:53.120> time<00:10:53.360> to<00:10:53.560> time<00:10:54.519> now<00:10:54.639> your
that happens from time to time now your
that happens from time to time now your
homework<00:10:55.200> assignment<00:10:55.959> is<00:10:56.079> to<00:10:56.279> really<00:10:56.600> think
homework assignment is to really think
homework assignment is to really think
about<00:10:57.240> this<00:10:57.440> to<00:10:57.639> contemplate<00:10:58.120> what<00:10:58.200> it<00:10:58.360> means
about this to contemplate what it means
about this to contemplate what it means
Carl<00:10:59.600> Sean<00:11:00.079> once<00:11:00.320> famously<00:11:00.760> said<00:11:01.000> that<00:11:01.160> in
Carl Sean once famously said that in
Carl Sean once famously said that in
order<00:11:01.600> to<00:11:01.800> make<00:11:02.079> an<00:11:02.240> apple<00:11:02.600> pie<00:11:03.040> you<00:11:03.160> must<00:11:03.440> F
order to make an apple pie you must F
order to make an apple pie you must F
first<00:11:04.079> invent<00:11:04.399> the<00:11:04.720> universe<00:11:05.720> but<00:11:05.839> he<00:11:06.000> was<00:11:06.200> not
first invent the universe but he was not
first invent the universe but he was not
right<00:11:07.639> in<00:11:07.800> boltzman's<00:11:08.360> scenario<00:11:09.120> if<00:11:09.200> you<00:11:09.279> want
right in boltzman's scenario if you want
right in boltzman's scenario if you want
to<00:11:09.519> make<00:11:09.639> an<00:11:09.800> apple<00:11:10.120> pie<00:11:10.320> you<00:11:10.480> just<00:11:10.680> wait<00:11:11.040> for
to make an apple pie you just wait for
to make an apple pie you just wait for
the<00:11:11.360> random<00:11:12.240> motion<00:11:12.519> of<00:11:12.720> Adams<00:11:13.079> to<00:11:13.240> make<00:11:13.360> you
the random motion of Adams to make you
the random motion of Adams to make you
an<00:11:13.639> apple
an apple
an apple
pie<00:11:15.519> that<00:11:15.680> will<00:11:16.000> happen<00:11:16.519> much<00:11:16.760> more
pie that will happen much more
pie that will happen much more
frequently<00:11:17.639> than<00:11:17.800> the<00:11:17.959> random<00:11:18.279> motions
frequently than the random motions
frequently than the random motions
motions<00:11:19.240> of<00:11:19.399> Adams<00:11:19.800> making<00:11:20.079> you<00:11:20.360> an<00:11:20.560> apple
motions of Adams making you an apple
motions of Adams making you an apple
orchard<00:11:21.680> and<00:11:21.800> some<00:11:22.079> sugar<00:11:22.560> and<00:11:22.680> an<00:11:22.839> oven<00:11:23.320> and
orchard and some sugar and an oven and
orchard and some sugar and an oven and
then<00:11:23.680> making<00:11:23.959> you<00:11:24.120> an<00:11:24.279> apple<00:11:24.880> pie<00:11:25.880> so<00:11:26.240> this
then making you an apple pie so this
then making you an apple pie so this
scenario<00:11:27.839> makes<00:11:28.360> predictions<00:11:29.360> and<00:11:29.480> the
scenario makes predictions and the
scenario makes predictions and the
predictions<00:11:30.200> are<00:11:30.519> that<00:11:30.639> the<00:11:30.800> fluctuations
predictions are that the fluctuations
predictions are that the fluctuations
that<00:11:31.920> make<00:11:32.200> us<00:11:32.440> are<00:11:33.040> minimal<00:11:34.040> even<00:11:34.279> if<00:11:34.480> you
that make us are minimal even if you
that make us are minimal even if you
imagine<00:11:35.160> that<00:11:35.360> this<00:11:36.040> room<00:11:36.360> we<00:11:36.480> are<00:11:36.639> in<00:11:36.839> now
imagine that this room we are in now
imagine that this room we are in now
exists<00:11:37.519> and<00:11:37.680> is<00:11:37.880> real<00:11:38.079> and<00:11:38.279> here<00:11:38.440> we<00:11:38.560> are<00:11:38.720> and
exists and is real and here we are and
exists and is real and here we are and
we<00:11:39.000> have<00:11:39.440> not<00:11:39.639> only<00:11:40.000> our<00:11:40.440> memories<00:11:40.920> but<00:11:41.040> our
we have not only our memories but our
we have not only our memories but our
Impressions<00:11:41.560> that<00:11:41.760> outside<00:11:42.120> there's
Impressions that outside there's
Impressions that outside there's
something<00:11:42.600> called<00:11:43.200> Caltech<00:11:43.839> in<00:11:43.959> the<00:11:44.040> United
something called Caltech in the United
something called Caltech in the United
States<00:11:44.600> and<00:11:44.720> the<00:11:44.760> Milky<00:11:45.120> Way<00:11:45.519> galaxy<00:11:46.519> it's
States and the Milky Way galaxy it's
States and the Milky Way galaxy it's
much<00:11:47.120> easier<00:11:47.519> for<00:11:47.680> all<00:11:47.839> those<00:11:48.040> Impressions<00:11:48.440> to
much easier for all those Impressions to
much easier for all those Impressions to
randomly<00:11:49.079> fluctuate<00:11:49.560> into<00:11:49.760> your<00:11:49.920> brain<00:11:50.200> than
randomly fluctuate into your brain than
randomly fluctuate into your brain than
for<00:11:50.480> them<00:11:50.720> actually<00:11:51.040> to<00:11:51.200> randomly<00:11:51.560> fluctuate
for them actually to randomly fluctuate
for them actually to randomly fluctuate
into<00:11:52.279> Caltech<00:11:52.880> the<00:11:53.000> United<00:11:53.320> States<00:11:53.600> and<00:11:53.720> the
into Caltech the United States and the
into Caltech the United States and the
Galaxy<00:11:55.079> the<00:11:55.240> good<00:11:55.440> news<00:11:55.760> is<00:11:56.000> that<00:11:56.320> therefore
Galaxy the good news is that therefore
Galaxy the good news is that therefore
this<00:11:57.320> scenario<00:11:57.880> does<00:11:58.079> not<00:11:58.240> work<00:11:58.519> it<00:11:58.600> is<00:11:58.760> not
this scenario does not work it is not
this scenario does not work it is not
right<00:12:00.040> this<00:12:00.160> scenario<00:12:00.680> predicts<00:12:01.040> that<00:12:01.160> we
right this scenario predicts that we
right this scenario predicts that we
should<00:12:01.399> be<00:12:01.519> a<00:12:01.639> minimal<00:12:02.079> fluctuation<00:12:02.800> even<00:12:02.959> if
should be a minimal fluctuation even if
should be a minimal fluctuation even if
you<00:12:03.200> get<00:12:03.440> our<00:12:03.760> galaxy<00:12:04.240> out<00:12:04.600> you<00:12:04.720> would<00:12:04.880> not<00:12:05.000> get
you get our galaxy out you would not get
you get our galaxy out you would not get
100<00:12:05.560> billion<00:12:05.920> other<00:12:06.240> galaxies<00:12:07.200> and<00:12:07.320> feeman
100 billion other galaxies and feeman
100 billion other galaxies and feeman
also<00:12:08.120> understood<00:12:08.680> this<00:12:08.920> feeman<00:12:09.440> says<00:12:10.079> from
also understood this feeman says from
also understood this feeman says from
the<00:12:10.399> hypothesis<00:12:10.959> that<00:12:11.079> the<00:12:11.160> world<00:12:11.360> is<00:12:11.480> a
the hypothesis that the world is a
the hypothesis that the world is a
fluctuation<00:12:12.440> all<00:12:12.680> the<00:12:12.920> predictions<00:12:13.920> are<00:12:14.079> that
fluctuation all the predictions are that
fluctuation all the predictions are that
if<00:12:14.279> we<00:12:14.440> look<00:12:14.560> at<00:12:14.680> a<00:12:14.800> part<00:12:15.000> of<00:12:15.120> the<00:12:15.199> world<00:12:15.399> we've
if we look at a part of the world we've
if we look at a part of the world we've
never<00:12:15.760> seen<00:12:16.079> before<00:12:16.399> we<00:12:16.480> will<00:12:16.639> find<00:12:16.800> it<00:12:17.000> mixed
never seen before we will find it mixed
never seen before we will find it mixed
up<00:12:17.760> not<00:12:18.000> like<00:12:18.160> the<00:12:18.279> piece<00:12:18.480> we've<00:12:18.680> just<00:12:18.800> looked
up not like the piece we've just looked
up not like the piece we've just looked
at<00:12:19.320> high<00:12:19.519> entropy<00:12:20.440> if<00:12:20.560> our<00:12:20.760> order<00:12:21.079> were<00:12:21.240> due<00:12:21.399> to
at high entropy if our order were due to
at high entropy if our order were due to
a<00:12:21.639> fluctuation<00:12:22.199> we<00:12:22.320> would<00:12:22.480> not<00:12:22.680> expect<00:12:23.040> order
a fluctuation we would not expect order
a fluctuation we would not expect order
anywhere<00:12:23.839> but<00:12:24.040> where<00:12:24.199> we've<00:12:24.480> just<00:12:24.639> noticed<00:12:25.079> it
anywhere but where we've just noticed it
anywhere but where we've just noticed it
we<00:12:25.720> therefore<00:12:26.120> conclude<00:12:26.560> the<00:12:26.680> universe<00:12:27.040> is
we therefore conclude the universe is
we therefore conclude the universe is
not<00:12:27.839> a<00:12:28.040> fluctuation
not a fluctuation
not a fluctuation
so<00:12:29.720> that's<00:12:30.000> good<00:12:30.240> the<00:12:30.360> question<00:12:30.600> is<00:12:30.800> then<00:12:30.959> what
so that's good the question is then what
so that's good the question is then what
is<00:12:31.199> the<00:12:31.440> right<00:12:31.839> answer<00:12:32.079> if<00:12:32.199> the<00:12:32.279> universe<00:12:32.600> is
is the right answer if the universe is
is the right answer if the universe is
not<00:12:32.880> a<00:12:33.079> fluctuation<00:12:34.079> why<00:12:34.279> did<00:12:34.440> the<00:12:34.560> early
not a fluctuation why did the early
not a fluctuation why did the early
Universe<00:12:35.279> have<00:12:35.399> a<00:12:35.519> low<00:12:35.720> entropy<00:12:36.680> and<00:12:36.920> I<00:12:37.000> would
Universe have a low entropy and I would
Universe have a low entropy and I would
love<00:12:37.240> to<00:12:37.360> tell<00:12:37.480> you<00:12:37.639> the<00:12:37.760> answer<00:12:38.040> but<00:12:38.160> I'm
love to tell you the answer but I'm
love to tell you the answer but I'm
running<00:12:38.519> out<00:12:38.639> of
running out of
running out of
time<00:12:41.720> here<00:12:42.040> is<00:12:42.480> the<00:12:42.639> universe<00:12:43.079> that<00:12:43.199> we<00:12:43.360> tell
time here is the universe that we tell
time here is the universe that we tell
you<00:12:43.760> about<00:12:44.000> versus<00:12:44.279> the<00:12:44.399> universe<00:12:44.720> that
you about versus the universe that
you about versus the universe that
really<00:12:45.240> exists<00:12:45.839> I<00:12:45.920> just<00:12:46.040> showed<00:12:46.320> you<00:12:46.519> this
really exists I just showed you this
really exists I just showed you this
picture<00:12:47.000> the<00:12:47.079> universe<00:12:47.399> is<00:12:47.519> expanding<00:12:47.920> for
picture the universe is expanding for
picture the universe is expanding for
the<00:12:48.240> last<00:12:48.480> 10<00:12:48.720> billion<00:12:49.040> years<00:12:49.240> or<00:12:49.440> so<00:12:49.920> it's
the last 10 billion years or so it's
the last 10 billion years or so it's
cooling<00:12:50.600> off<00:12:51.240> but<00:12:51.360> we<00:12:51.519> now<00:12:51.760> know<00:12:52.040> enough<00:12:52.279> about
cooling off but we now know enough about
cooling off but we now know enough about
the<00:12:52.639> future<00:12:53.199> of<00:12:53.360> the<00:12:53.480> universe<00:12:53.959> to<00:12:54.160> say<00:12:54.360> a<00:12:54.480> lot
the future of the universe to say a lot
the future of the universe to say a lot
more<00:12:54.959> if<00:12:55.079> the<00:12:55.240> dark<00:12:55.480> energy<00:12:56.120> remains<00:12:56.639> around
more if the dark energy remains around
more if the dark energy remains around
the<00:12:57.800> Stars<00:12:58.199> around<00:12:58.440> us<00:12:58.600> will<00:12:58.880> use<00:12:59.040> up<00:12:59.199> their
the Stars around us will use up their
the Stars around us will use up their
nuclear<00:12:59.680> fuel<00:13:00.000> they<00:13:00.079> will<00:13:00.279> stop<00:13:00.560> burning<00:13:01.240> they
nuclear fuel they will stop burning they
nuclear fuel they will stop burning they
will<00:13:01.480> fall<00:13:01.800> into<00:13:02.120> black<00:13:02.360> holes<00:13:02.959> we<00:13:03.040> will<00:13:03.199> live
will fall into black holes we will live
will fall into black holes we will live
in<00:13:03.480> a<00:13:03.639> universe<00:13:04.120> with<00:13:04.360> nothing<00:13:04.720> in<00:13:04.839> it<00:13:05.320> but
in a universe with nothing in it but
in a universe with nothing in it but
black<00:13:06.079> holes<00:13:07.079> that<00:13:07.440> universe<00:13:07.920> will<00:13:08.160> last<00:13:08.440> 10
black holes that universe will last 10
black holes that universe will last 10
to<00:13:08.959> the<00:13:09.360> 100<00:13:09.720> years<00:13:10.399> a<00:13:10.519> lot<00:13:10.720> longer<00:13:11.040> than<00:13:11.199> our
to the 100 years a lot longer than our
to the 100 years a lot longer than our
little<00:13:11.639> Universe<00:13:12.120> has<00:13:12.279> lived<00:13:12.639> the<00:13:12.760> future<00:13:13.040> is
little Universe has lived the future is
little Universe has lived the future is
much<00:13:13.399> longer<00:13:13.680> than<00:13:13.839> the<00:13:14.040> past<00:13:14.959> but<00:13:15.120> even<00:13:15.360> black
much longer than the past but even black
much longer than the past but even black
holes<00:13:15.920> don't<00:13:16.199> last<00:13:16.399> forever<00:13:16.880> they<00:13:16.959> will
holes don't last forever they will
holes don't last forever they will
evaporate<00:13:17.800> and<00:13:17.920> we<00:13:18.000> will<00:13:18.120> be<00:13:18.279> left<00:13:18.480> with
evaporate and we will be left with
evaporate and we will be left with
nothing<00:13:19.000> but<00:13:19.199> empty<00:13:19.639> space<00:13:20.639> that<00:13:20.760> empty<00:13:21.120> space
nothing but empty space that empty space
nothing but empty space that empty space
lasts<00:13:22.120> essentially<00:13:23.560> forever<00:13:24.560> however<00:13:24.760> you
lasts essentially forever however you
lasts essentially forever however you
notice<00:13:25.199> that<00:13:25.360> since<00:13:25.560> empty<00:13:25.920> space<00:13:26.320> gives<00:13:26.560> off
notice that since empty space gives off
notice that since empty space gives off
radiation<00:13:27.680> there's<00:13:27.880> actually<00:13:28.160> thermal
radiation there's actually thermal
radiation there's actually thermal
fluctu<00:13:28.959> ation<00:13:29.240> and<00:13:29.399> it<00:13:29.560> Cycles<00:13:30.079> around<00:13:31.000> all
fluctu ation and it Cycles around all
fluctu ation and it Cycles around all
the<00:13:31.519> different<00:13:32.000> possible<00:13:32.760> combinations<00:13:33.760> of
the different possible combinations of
the different possible combinations of
the<00:13:34.040> degrees<00:13:34.440> of<00:13:34.600> freedom<00:13:35.040> that<00:13:35.279> exist<00:13:35.639> in
the degrees of freedom that exist in
the degrees of freedom that exist in
empty<00:13:36.240> space<00:13:37.079> so<00:13:37.199> even<00:13:37.360> though<00:13:37.519> the<00:13:37.600> universe
empty space so even though the universe
empty space so even though the universe
lasts<00:13:38.360> forever<00:13:38.720> there's<00:13:38.880> only<00:13:39.000> a<00:13:39.079> finite
lasts forever there's only a finite
lasts forever there's only a finite
number<00:13:39.560> of<00:13:39.680> things<00:13:39.880> that<00:13:40.040> can<00:13:40.320> possibly
number of things that can possibly
number of things that can possibly
happen<00:13:41.079> in<00:13:41.199> the<00:13:41.399> universe<00:13:42.399> they<00:13:42.600> all<00:13:42.880> happen
happen in the universe they all happen
happen in the universe they all happen
over<00:13:43.360> a<00:13:43.480> period<00:13:43.760> of<00:13:43.920> time<00:13:44.160> equal<00:13:44.399> to<00:13:44.560> 10<00:13:44.880> to<00:13:45.079> the
over a period of time equal to 10 to the
over a period of time equal to 10 to the
10<00:13:45.440> to<00:13:45.639> the<00:13:45.760> 120<00:13:47.240> years<00:13:48.240> so<00:13:48.480> here's<00:13:48.760> two
10 to the 120 years so here's two
10 to the 120 years so here's two
questions<00:13:49.360> for<00:13:49.519> you<00:13:49.720> number<00:13:50.000> one<00:13:50.360> if<00:13:50.480> the
questions for you number one if the
questions for you number one if the
universe<00:13:51.000> lasts<00:13:51.279> for<00:13:51.399> 10<00:13:51.600> to<00:13:51.720> the<00:13:51.800> 10<00:13:51.959> to<00:13:52.079> the
universe lasts for 10 to the 10 to the
universe lasts for 10 to the 10 to the
120<00:13:52.680> years<00:13:53.560> why<00:13:53.759> are<00:13:53.959> we<00:13:54.199> born<00:13:54.759> in<00:13:54.880> the<00:13:55.040> first
120 years why are we born in the first
120 years why are we born in the first
14<00:13:55.800> billion<00:13:56.199> years<00:13:56.639> of<00:13:56.800> it<00:13:57.240> in<00:13:57.399> the<00:13:57.560> warm
14 billion years of it in the warm
14 billion years of it in the warm
comfortable<00:13:59.120> Afterglow<00:13:59.720> of<00:13:59.839> the<00:14:00.000> Big<00:14:00.279> Bang
comfortable Afterglow of the Big Bang
comfortable Afterglow of the Big Bang
why<00:14:01.360> aren't<00:14:01.839> we<00:14:02.360> in<00:14:02.560> empty<00:14:02.959> space<00:14:03.519> you<00:14:03.680> might
why aren't we in empty space you might
why aren't we in empty space you might
say<00:14:04.040> well<00:14:04.160> there's<00:14:04.320> nothing<00:14:04.600> there<00:14:04.759> to<00:14:04.880> be
say well there's nothing there to be
say well there's nothing there to be
living<00:14:05.440> but<00:14:05.600> that's<00:14:05.800> not<00:14:06.120> right<00:14:06.800> you<00:14:06.920> could<00:14:07.079> be
living but that's not right you could be
living but that's not right you could be
a<00:14:07.399> random<00:14:07.839> fluctuation<00:14:08.560> out<00:14:08.720> of<00:14:08.880> the
a random fluctuation out of the
a random fluctuation out of the
nothingness<00:14:09.800> why<00:14:10.000> aren't<00:14:10.399> you<00:14:11.000> more<00:14:11.279> homework
nothingness why aren't you more homework
nothingness why aren't you more homework
assignment<00:14:12.079> for<00:14:12.720> you<00:14:13.720> so<00:14:13.959> like<00:14:14.040> I<00:14:14.160> said<00:14:14.320> I
assignment for you so like I said I
assignment for you so like I said I
don't<00:14:14.720> actually<00:14:14.959> know<00:14:15.160> the<00:14:15.279> answer<00:14:15.600> I'm<00:14:15.720> going
don't actually know the answer I'm going
don't actually know the answer I'm going
to<00:14:15.920> give<00:14:16.000> you<00:14:16.120> my<00:14:16.240> favorite<00:14:16.600> scenario<00:14:17.360> either
to give you my favorite scenario either
to give you my favorite scenario either
it's<00:14:18.440> just<00:14:18.759> like<00:14:19.079> that<00:14:19.680> there<00:14:19.800> is<00:14:20.000> no
it's just like that there is no
it's just like that there is no
explanation<00:14:20.800> this<00:14:20.920> is<00:14:21.040> a<00:14:21.199> brute<00:14:21.759> fact<00:14:22.000> about
explanation this is a brute fact about
explanation this is a brute fact about
the<00:14:22.320> universe<00:14:22.720> that<00:14:22.800> you<00:14:22.880> should<00:14:23.000> learn<00:14:23.199> to
the universe that you should learn to
the universe that you should learn to
accept<00:14:23.639> and<00:14:23.839> stop<00:14:24.120> asking
accept and stop asking
accept and stop asking
questions<00:14:26.440> or<00:14:26.680> maybe<00:14:27.160> the<00:14:27.360> Big<00:14:27.600> Bang<00:14:27.959> is<00:14:28.120> not
questions or maybe the Big Bang is not
questions or maybe the Big Bang is not
the<00:14:28.360> beginning
the beginning
the beginning
of<00:14:29.560> the<00:14:29.720> universe<00:14:30.519> an<00:14:30.759> egg<00:14:31.120> an<00:14:31.279> unbroken<00:14:31.759> egg
of the universe an egg an unbroken egg
of the universe an egg an unbroken egg
is<00:14:32.079> a<00:14:32.160> low<00:14:32.360> entropy<00:14:32.839> configuration<00:14:33.560> And<00:14:33.680> yet
is a low entropy configuration And yet
is a low entropy configuration And yet
when<00:14:33.959> we<00:14:34.079> open<00:14:34.279> our<00:14:34.480> refrigerator<00:14:35.040> we<00:14:35.120> do<00:14:35.240> not
when we open our refrigerator we do not
when we open our refrigerator we do not
go<00:14:35.680> ha<00:14:36.240> how<00:14:36.440> surprising<00:14:37.000> to<00:14:37.160> find<00:14:37.360> this<00:14:37.480> low
go ha how surprising to find this low
go ha how surprising to find this low
entropy<00:14:38.120> configuration<00:14:38.639> in<00:14:38.759> our
entropy configuration in our
entropy configuration in our
refrigerator<00:14:40.199> that's<00:14:40.440> because<00:14:40.680> an<00:14:40.800> egg<00:14:41.040> is
refrigerator that's because an egg is
refrigerator that's because an egg is
not<00:14:41.279> a<00:14:41.480> closed<00:14:42.240> system<00:14:42.639> it<00:14:42.759> comes<00:14:42.959> out<00:14:43.079> of<00:14:43.199> a
not a closed system it comes out of a
not a closed system it comes out of a
chicken<00:14:44.759> maybe<00:14:45.000> the<00:14:45.199> universe<00:14:45.959> comes<00:14:46.240> out<00:14:46.480> of
chicken maybe the universe comes out of
chicken maybe the universe comes out of
a<00:14:46.800> universal
a universal
a universal
chicken<00:14:49.199> maybe<00:14:49.440> there<00:14:49.560> is<00:14:49.839> something<00:14:50.279> that
chicken maybe there is something that
chicken maybe there is something that
naturally<00:14:50.959> through<00:14:51.199> the<00:14:51.399> EXP<00:14:51.839> through<00:14:52.040> the
naturally through the EXP through the
naturally through the EXP through the
growth<00:14:52.839> of<00:14:52.920> the<00:14:53.040> laws<00:14:53.279> of<00:14:53.440> physics<00:14:54.040> gives<00:14:54.399> rise
growth of the laws of physics gives rise
growth of the laws of physics gives rise
to<00:14:54.880> Universe<00:14:55.440> like<00:14:55.639> ours<00:14:56.199> in<00:14:56.480> low<00:14:56.759> entropy
to Universe like ours in low entropy
to Universe like ours in low entropy
configurations<00:14:58.360> if<00:14:58.519> that<00:14:58.720> that's<00:14:58.880> true<00:14:59.040> it
configurations if that that's true it
configurations if that that's true it
would<00:14:59.320> happen<00:14:59.519> more<00:14:59.720> than<00:14:59.880> once<00:15:00.199> we<00:15:00.320> would<00:15:00.440> be
would happen more than once we would be
would happen more than once we would be
part<00:15:00.800> of<00:15:00.920> a<00:15:01.079> much<00:15:01.320> bigger<00:15:01.959> Multiverse<00:15:02.759> that's
part of a much bigger Multiverse that's
part of a much bigger Multiverse that's
my<00:15:03.120> favorite<00:15:03.440> scenario<00:15:04.399> so<00:15:04.519> the<00:15:04.639> organizers
my favorite scenario so the organizers
my favorite scenario so the organizers
asked<00:15:05.399> me<00:15:05.519> to<00:15:05.639> end<00:15:05.959> with<00:15:06.399> a<00:15:06.639> bold<00:15:07.079> speculation
asked me to end with a bold speculation
asked me to end with a bold speculation
my<00:15:08.240> bold<00:15:08.600> speculation<00:15:09.160> is<00:15:09.320> that<00:15:09.440> I<00:15:09.519> will<00:15:09.680> be
my bold speculation is that I will be
my bold speculation is that I will be
absolutely<00:15:10.600> Vindicated<00:15:11.279> by<00:15:11.560> history<00:15:12.560> and<00:15:13.079> 50
absolutely Vindicated by history and 50
absolutely Vindicated by history and 50
years<00:15:13.720> from<00:15:13.920> now<00:15:14.240> all<00:15:14.399> of<00:15:14.560> my<00:15:14.839> current<00:15:15.320> wild
years from now all of my current wild
years from now all of my current wild
ideas<00:15:16.120> will<00:15:16.279> be<00:15:16.519> accepted<00:15:17.079> as<00:15:17.279> truths<00:15:18.199> by<00:15:18.360> the
ideas will be accepted as truths by the
ideas will be accepted as truths by the
scientific<00:15:18.959> and<00:15:19.120> external<00:15:19.560> communities<00:15:20.399> we
scientific and external communities we
scientific and external communities we
will<00:15:20.720> all<00:15:20.959> believe<00:15:21.639> that<00:15:21.880> our<00:15:22.079> little
will all believe that our little
will all believe that our little
universe<00:15:22.759> is<00:15:22.920> just<00:15:23.000> a<00:15:23.120> small<00:15:23.399> part<00:15:23.560> of<00:15:23.639> a<00:15:23.759> much
universe is just a small part of a much
universe is just a small part of a much
larger<00:15:24.360> Multiverse<00:15:25.360> and<00:15:25.519> even<00:15:25.720> better<00:15:25.920> we
larger Multiverse and even better we
larger Multiverse and even better we
will<00:15:26.720> understand<00:15:27.720> what<00:15:27.959> happened<00:15:28.319> at<00:15:28.440> the<00:15:28.720> Big
will understand what happened at the Big
will understand what happened at the Big
Bang<00:15:29.319> in<00:15:29.440> terms<00:15:29.720> of<00:15:29.839> a<00:15:30.040> theory<00:15:30.600> that<00:15:30.720> we<00:15:30.839> be
Bang in terms of a theory that we be
Bang in terms of a theory that we be
able<00:15:31.120> to<00:15:31.279> compare<00:15:31.720> to<00:15:32.040> observations<00:15:32.800> this<00:15:32.920> is
able to compare to observations this is
able to compare to observations this is
a<00:15:33.160> prediction<00:15:33.959> I<00:15:34.079> might<00:15:34.279> be<00:15:34.480> wrong<00:15:34.920> but<00:15:35.399> we've
a prediction I might be wrong but we've
a prediction I might be wrong but we've
been<00:15:35.800> thinking<00:15:36.160> as<00:15:36.279> a<00:15:36.399> human<00:15:36.800> race<00:15:37.600> about<00:15:37.920> what
been thinking as a human race about what
been thinking as a human race about what
the<00:15:38.199> universe<00:15:38.839> was<00:15:39.079> like<00:15:39.440> why<00:15:39.600> it<00:15:39.759> came<00:15:39.959> to<00:15:40.079> be
the universe was like why it came to be
the universe was like why it came to be
in<00:15:40.360> the<00:15:40.480> way<00:15:40.600> it<00:15:40.720> did<00:15:40.920> for<00:15:41.040> many<00:15:41.279> many<00:15:41.560> years
in the way it did for many many years
in the way it did for many many years
it's<00:15:42.079> exciting<00:15:42.440> to<00:15:42.639> think<00:15:43.160> we<00:15:43.319> may<00:15:43.480> finally
it's exciting to think we may finally
it's exciting to think we may finally
know<00:15:43.959> the<00:15:44.079> answer<00:15:44.360> someday<00:15:45.079> thank
know the answer someday thank
know the answer someday thank
[Applause]
you
Sean Carroll, TED, TEDx, TEDxCaltech, Cal, Tech, time, universe, multiverse, nature, of, universe, TED-Ed, TED, Ed, TEDEducation, physics
