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Transcript
· Intro
0:00 · and there's a little bizarre series
0:01 · about the universe some of them are
0:03 · already debunked bordering on conspiracy
0:05 · theories or are just downright silly
0:06 · other Tsar Milly Cosmic thought
0:07 · experiments they can't be proven one way
0:09 · or the other and are just ideas designed
0:11 · to challenge what we believe about the
0:13 · universe all around us while in same
0:16 · conspiracy theories and unprovable
0:18 · thought experiments can be fun today
0:19 · we're going to look at four theories
0:21 · that may actually be true and one that
0:24 · almost certainly is but we'd definitely
0:27 · prefer that it totally was
0:30 · foreign
0:32 · [Music]
· Theres a fourth spatial dimension
0:37 · there's a fourth spatial dimension
0:42 · one of the major problems in the
0:44 · standard model of physics is try to
0:45 · explain why the gravitational force is
0:47 · so weak when compared to the three other
0:49 · Natural Forces according to the theory
0:51 · at the time the Big Bang all four forces
0:54 · should have existed as one before
0:55 · breaking off into the four forces that
0:58 · we observed today but at the point when
1:01 · they split they should have been
1:03 · comparable in strength so why then is
1:06 · gravity so weak String Theory attempted
1:09 · to address this problem by positing that
1:11 · at tiny enough distances the forces
1:13 · could be equal in magnitude but this
1:15 · isn't an ideal answer and scientists
1:17 · kept on searching in 1983 the idea of
1:20 · brain cosmology was introduced though
1:23 · the most influential model would not be
1:24 · proposed until 1999 by physicists Lisa
1:27 · Randall and romance sunroom the idea of
1:29 · brain cosmology also referred to as
1:31 · brainworld is that there is at least a
1:35 · fourth spatial Dimension and possibly
1:37 · even more now we're all familiar with
1:39 · the three spatial Dimensions plus the
1:42 · fourth time dimension in which we exist
1:45 · and that seems to be pretty
1:47 · encapsulating of the entire universe so
1:49 · how then could there be further spatial
1:53 · Dimensions well the answer to that is
1:55 · that our universe is trapped inside a
1:57 · membrane hence the brain in the Theory's
2:00 · name our visible Universe exists
2:01 · entirely within this membrane while the
2:03 · majority of what exists also referred to
2:05 · as the bulk is some sort of higher
2:08 · dimensional space outside of the
2:09 · membrane now it may sound a little bit
2:11 · far-fetched but this theory is being
2:13 · seriously pursued by scientists as a
2:16 · possible solution to many of the
2:17 · unanswered questions about the universe
2:19 · under this Theory the weak and strong
2:21 · nuclear forces in the electromagnetic
2:23 · force are trapped within the membrane
2:25 · but the gravitational force has no such
2:27 · restriction as such much of the
2:29 · gravitational force leaks out into the
2:31 · bulk this accounts for why it is so
2:34 · comparatively weak similarly other
2:35 · membranes could exist next to us which
2:37 · also influence the gravitational force
2:39 · there could be other universes Trapped
2:41 · In Their Own own membranes only a
2:43 · microscopic distance away from ours but
2:45 · because they could exist in spatial
2:46 · Dimensions that are completely
2:48 · imperceptible to us we would have no
2:51 · idea that they were even there it is
2:54 · regarded as one of the more elegant
2:56 · solutions for the hierarchy problem and
2:59 · experiments have been designed to try
3:00 · and prove the existence of large extra
3:02 · Dimensions thus far these have not
3:04 · yielded any results other than to
3:06 · constrain what the extra Dimensions
3:08 · could actually be then again because we
3:10 · are trying to test for extra spatial
3:12 · Dimensions that we don't actually know
3:14 · how to perceive detecting evidence of
3:16 · their existence may prove to be more
3:18 · complicated than we realized
· Gravity may be wrong
3:21 · gravity may be wrong
3:25 · okay once again we find ourselves faced
3:28 · with the issue of gravity the
3:29 · gravitational force was naturally the
3:31 · first of the four forces that humans
3:33 · discovered if you drop something it
3:35 · falls down seems pretty straightforward
3:38 · however of the four natural forces
3:40 · gravity is the one we actually
3:42 · understand the least we do have a pretty
3:44 · good idea of how gravity works or at
3:46 · least how we think it works despite the
3:48 · hierarchy problem presented by it being
3:50 · so many orders of magnitude weaker than
3:52 · the other forces however we have seen
3:54 · other issues related to our
3:56 · understanding of gravity as well one
3:58 · such problem is the speed at which
3:59 · celestial bodies move we can observe
4:01 · galaxies rotating much faster than they
4:03 · should be able to or we could see
4:05 · galaxies traveling away from us at
4:06 · speeds far exceeding what should even be
4:09 · possible scientists have proposed a
4:11 · solution to this dilemma in the form of
4:14 · Dark Matter dark matter is everywhere in
4:16 · the universe accounting for roughly 85
4:18 · percent of all matter it is six times
4:20 · more abundant than the visible matter
4:22 · that we're familiar with this dark
4:24 · matter and the gravity exerted by its is
4:26 · the reason we see objects moving in ways
4:28 · that would otherwise be impossible to
4:30 · explain however Dark Matter does not
4:33 · interact with the electromagnetic force
4:34 · this means it does not absorb reflect or
4:37 · emit light making it completely
4:39 · invisible and well that's how it got its
4:42 · name the only problem is that because
4:44 · it's invisible we have no proof that
4:46 · dark matter actually exists the only
4:48 · proof for the existence of dark matter
4:50 · is the gravitational effect that it has
4:52 · on other objects throughout the Universe
4:54 · now so you may have noticed that it's a
4:56 · bit of a logical problem there the only
4:58 · proof we have the Dark Matter exists is
5:00 · the gravitational effect that it has but
5:02 · Dark Matter was proposed as a
5:05 · theoretical solution for gravitational
5:07 · effects that we couldn't otherwise
5:10 · explain it somewhat circular reasoning
5:12 · there which is why experiments like
5:14 · those at the Large Hadron Collider hope
5:16 · to provide more concrete proof for the
5:18 · existence of Dark Matter however there
5:22 · is another possible solution it could be
5:24 · wrong notice about dark matter
5:26 · but about gravity itself in fact we
5:29 · already know that the current series of
5:31 · gravity are wrong and this isn't the
5:33 · first time that we've made that
5:34 · Discovery gravity is put forth by Isaac
5:37 · Newton worked great for a while he
5:39 · described gravity as an attractive Force
5:40 · but there were some problems for example
5:42 · Mercury's orbit moved closer to the Sun
5:44 · at a faster rate than Newton's equations
5:46 · predicted Einstein's general relativity
5:48 · solved this problem and changed our
5:50 · understanding of gravity rather than
5:51 · being an attractive Force Einstein saw
5:54 · gravity as warping space-time around an
5:57 · object thus creating a well that other
6:00 · things would fall towards this new
6:02 · understanding remained consistent with
6:03 · everything that was expected from
6:05 · Newtonian physics while also correcting
6:07 · issues in the areas are Newton's
6:09 · formulas didn't work unfortunately
6:11 · general relativity also breaks down as
6:13 · well we just aren't exactly sure where
6:15 · we know that at some point within a
6:17 · black hole that Einstein's theory stops
6:20 · working and research is currently
6:21 · working to figure out where exactly once
6:25 · we know the exact point where breaks
6:27 · down we may be able to figure out
6:28 · exactly what was wrong until that
6:31 · happens it's hard to say exactly what
6:33 · the fate of gravity will be perhaps our
6:35 · new understanding of the gravitational
6:36 · force will still require the existence
6:39 · of dark matter or perhaps we will learn
6:41 · the double Leafs about gravity were just
6:43 · so fundamentally flawed that dark matter
6:46 · is no longer necessary to reconcile our
6:49 · expectations with reality
· Speed of light may once have been faster
6:53 · the speed of light may once have been
6:55 · faster
6:57 · if you've ever taken a physics class you
6:59 · undoubtedly know that the speed of light
7:01 · in a vacuum is 300 000 kilometers a
7:03 · second and that is the fastest that
7:05 · anything in the universe can possibly
7:07 · travel at colder temperatures light
7:09 · moves more slowly not because the
7:11 · temperature itself but because colder
7:13 · temperatures make air more dense and
7:15 · light travels more slowly through denser
7:17 · objects but what if this worked in the
7:21 · other direction as well it's hard to
7:23 · imagine it being hot enough for a vacuum
7:25 · to somehow become even more of a vacuum
7:28 · however one Theory suggests that the
7:30 · origins of the universe it was so hot
7:31 · that light essentially underwent a phase
7:33 · change like water turning into steam as
7:36 · a result of this change light was able
7:38 · to far exceed its current maximum speed
7:40 · approaching effectively infinite speed
7:43 · this theory was proposed as an
7:45 · alternative to inflation Theory the most
7:47 · commonly accepted explanation for the
7:49 · Horizon problem in Cosmic microwave
7:52 · background or CMB The Horizon problem is
7:54 · that the temperature across the universe
7:56 · is even which should definitely not be
7:59 · possible likewise CMB is the oldest
8:01 · measurable light in the universe having
8:02 · been emitted out 300 000 years after the
8:05 · big bang and the light is equivalent
8:08 · everywhere the consistency of CMB shows
8:11 · that the temperature across the universe
8:12 · should have been the same but this
8:13 · doesn't make logical sense as the
8:15 · universe was so big that light and
8:18 · thusly heat should not have reached all
8:20 · of it the inflation theory proposes that
8:23 · a fraction of a second after the big
8:25 · bang the universe underwent a massive
8:27 · exponential expansion outward that
8:29 · lasted for only a fraction of a second
8:31 · as space-time expanded exponentially the
8:34 · existing light and heat was carried with
8:36 · it and then propagated as normal it's an
8:38 · elegant solution that answers a lot of
8:40 · problems and because it only happened
8:42 · once billions of years ago it's also
8:44 · well completely untestable in addition
8:47 · to being an untestable Theory it raises
8:50 · the question of why why would this have
8:52 · happened why for only such a short time
8:55 · and why never again these these are
8:57 · questions that we just don't have
9:00 · answers for because the untestable and
9:01 · difficult to rationalize nature of
9:03 · inflation the alternate theory was
9:05 · proposed that extremely high
9:06 · temperatures allowed light to travel in
9:08 · incredible speeds following the Big Bang
9:09 · This would run contrary to Weinstein's
9:12 · theory of special relativity but it does
9:13 · hold one advantage over inflation Theory
9:15 · the physicists who proposed the most
9:18 · recent iteration of the theory believed
9:20 · that they could actually prove it it is
9:22 · believed that in the near future the
9:23 · idea of a previously variable speed of
9:26 · light could be tested if so this Theory
9:28 · will live or die by the result of those
9:31 · experiments it's impossible to predict
9:32 · what the results would be but if testing
9:35 · were to confirm this Theory it would
9:36 · require rethinking much of what we
9:38 · believe we know about physics
· Adolf Hitler could make first contact with aliens
9:40 · Adolf Hitler could make first contact
9:42 · with extraterrestrials
9:45 · we're not proposing that Hitler at the
9:47 · age of 133 is alive and well in South
9:49 · America and will soon be launching
9:51 · himself into space to make first contact
9:52 · with an alien civilization though such a
9:55 · conspiracy theory probably does exist
9:57 · because of course it does instead we're
9:59 · going to be looking at an idea first
10:01 · presented by Carl Sagan in his 1985
10:03 · novel contact which was later adapted
10:06 · into a 1997 film starring Jodie Foster
10:09 · Humanity has been broadcasting messages
10:11 · into space for decades though much of it
10:14 · wasn't intentional most signals that
10:15 · were transmitted over the airwaves were
10:17 · either at too lower frequency or too low
10:20 · power to escape Earth's ionosphere
10:22 · however as Sagan put forth the First
10:24 · Signal broadcast that was powerful
10:25 · enough to escape Earth's atmosphere and
10:27 · travel into outer space was the opening
10:28 · ceremony of the 1936 Olympic Games in
10:31 · Berlin this could make Hitler's opening
10:32 · speech at the Olympics and alien
10:34 · civilizations first encounter with
10:36 · humans though contact was a fiction
10:39 · novel it was based in hard science many
10:41 · scientists dispute the claim that this
10:43 · will be the first transmission received
10:44 · by extra Industrials but they do admit
10:47 · that yeah
10:48 · it is actually possible although the
10:51 · signal was relatively weak compared to
10:52 · messages that have been beamed into
10:54 · space with more clear intent it could
10:57 · easily travel hundreds if not thousands
10:59 · of light years into space though
11:00 · scientists believe that because of the
11:02 · low intensity of the signal it is likely
11:04 · to be missed they state that aliens
11:06 · would need to be listening to the void
11:08 · of space extremely intently in order to
11:10 · find the signal while that is true
11:12 · there's no reason to believe that they
11:14 · wouldn't be doing exactly that after all
11:17 · we certainly are the bigger obstacle
11:19 · would be that whatever civilization were
11:21 · to encounter this broadcast may have no
11:23 · way to decode it they would certainly
11:25 · recognize it as a technological
11:26 · broadcast of some kind instead of
11:28 · something naturally occurring but that
11:30 · doesn't mean it would be able to
11:32 · separate the audio and the visual
11:33 · information from the signal and
11:35 · reproduce the video that was being
11:37 · broadcast around Earth it's
11:39 · understandable that scientists would
11:41 · want to try and debunk this Theory as
11:43 · best as possible given the rather
11:45 · non-controversial statement that Hitler
11:47 · was a bad dude however there is no
11:50 · denying that the Olympic broadcast was
11:52 · almost certainly the first man-made
11:53 · signal powerful enough to break through
11:55 · the ionosphere and that if aliens are
11:58 · looking hard enough they could find it
· You are a Boltzmann brain
12:01 · you are a boltzmann brain that's the
12:04 · heat death of the universe in 1896
12:07 · Austrian physicist Ludwig boltzmann
12:09 · first published a theory that tried to
12:12 · account for why the universe wasn't as
12:14 · chaotic as thermodynamics seemed to
12:16 · predict that it should be thermodynamics
12:18 · was a relatively new field at the time
12:20 · and one of the main principles of
12:21 · thermodynamics is that the Universe
12:23 · tries to maximize entropy or disorder
12:27 · the universe is over 13 billion years
12:28 · old which means that it had a long time
12:31 · to spiral into chaos so why then is
12:34 · everything in the universe so organized
12:36 · why does it follow these rigid and
12:39 · precise rules well the field of quantum
12:41 · physics didn't exist yet and the
12:43 · seemingly random nature of quantum
12:45 · particles had yet to be observed so this
12:47 · was a pretty logical question to ask it
12:49 · is paper boltzmann presented our
12:51 · hypothesis the hypothesis was that even
12:53 · after the universe had reached maximum
12:55 · entropy also known as the heat death of
12:58 · the universe that it would randomly
12:59 · undergo fluctuations to a more ordered
13:01 · State possibly creating something like
13:04 · the universe that we see today other
13:06 · cosmologist didn't believe this was
13:08 · likely and the boltzmann brain was
13:10 · proposed as a reductio and absurdum
13:12 · argument against the theory the idea is
13:15 · that smaller fluctuations are more
13:16 · likely than large ones as such it is
13:18 · more likely that the random fluctuations
13:20 · formed a single human brain full of
13:23 · false memories than it is to have formed
13:25 · the entirety of our observable universe
13:28 · it sounds like a silly idea because it
13:31 · was intended to be like Schrodinger's
13:33 · cat it was meant to be a ridiculous
13:36 · argument for a century it remained a
13:39 · ridiculous argument meant to disprove
13:41 · Boltzmann's Theory however in 2002
13:44 · something changed there's theories about
13:46 · the universe and a possible Multiverse
13:48 · became more advanced and better
13:50 · understood the maths showed something
13:52 · startling statistically speaking you are
13:56 · far more likely to be a boltzmann brain
13:58 · that randomly formed eons after the heat
14:01 · death of the universe and was filled
14:02 · with false memories including a belief
14:04 · that you existed a point when the
14:06 · universe was much younger obviously this
14:09 · was never the goal nobody is trying to
14:11 · prove that boltzmann brains exist
14:13 · they're trying to prove that they don't
14:16 · many scientists are able to Simply
14:18 · disregard the idea as being far too
14:20 · silly to be worth consideration but for
14:22 · others it's a serious problem in most
14:25 · theories of the universe it's less
14:26 · likely that the Universe actually exists
14:28 · as we believe it does and it's more
14:30 · likely that everyone who believes
14:31 · they're watching this video right now is
14:34 · boltzmann brain that randomly formed
14:36 · with false memories of having watched
14:39 · this video fortunately even those that
14:42 · view this as a problem with current
14:44 · theories don't believe it's the reality
14:46 · in which we're all living we just hope
14:48 · that someday that maths is uh going to
14:52 · agree with them
14:57 · [Music]

Transcript
	·	Intro
0:00	·	and there's a little bizarre series
0:01	·	about the universe some of them are
0:03	·	already debunked bordering on conspiracy
0:05	·	theories or are just downright silly
0:06	·	other Tsar Milly Cosmic thought
0:07	·	experiments they can't be proven one way
0:09	·	or the other and are just ideas designed
0:11	·	to challenge what we believe about the
0:13	·	universe all around us while in same
0:16	·	conspiracy theories and unprovable
0:18	·	thought experiments can be fun today
0:19	·	we're going to look at four theories
0:21	·	that may actually be true and one that
0:24	·	almost certainly is but we'd definitely
0:27	·	prefer that it totally was
0:30	·	foreign
0:32	·	[Music]
	·	Theres a fourth spatial dimension
0:37	·	there's a fourth spatial dimension
0:42	·	one of the major problems in the
0:44	·	standard model of physics is try to
0:45	·	explain why the gravitational force is
0:47	·	so weak when compared to the three other
0:49	·	Natural Forces according to the theory
0:51	·	at the time the Big Bang all four forces
0:54	·	should have existed as one before
0:55	·	breaking off into the four forces that
0:58	·	we observed today but at the point when
1:01	·	they split they should have been
1:03	·	comparable in strength so why then is
1:06	·	gravity so weak String Theory attempted
1:09	·	to address this problem by positing that
1:11	·	at tiny enough distances the forces
1:13	·	could be equal in magnitude but this
1:15	·	isn't an ideal answer and scientists
1:17	·	kept on searching in 1983 the idea of
1:20	·	brain cosmology was introduced though
1:23	·	the most influential model would not be
1:24	·	proposed until 1999 by physicists Lisa
1:27	·	Randall and romance sunroom the idea of
1:29	·	brain cosmology also referred to as
1:31	·	brainworld is that there is at least a
1:35	·	fourth spatial Dimension and possibly
1:37	·	even more now we're all familiar with
1:39	·	the three spatial Dimensions plus the
1:42	·	fourth time dimension in which we exist
1:45	·	and that seems to be pretty
1:47	·	encapsulating of the entire universe so
1:49	·	how then could there be further spatial
1:53	·	Dimensions well the answer to that is
1:55	·	that our universe is trapped inside a
1:57	·	membrane hence the brain in the Theory's
2:00	·	name our visible Universe exists
2:01	·	entirely within this membrane while the
2:03	·	majority of what exists also referred to
2:05	·	as the bulk is some sort of higher
2:08	·	dimensional space outside of the
2:09	·	membrane now it may sound a little bit
2:11	·	far-fetched but this theory is being
2:13	·	seriously pursued by scientists as a
2:16	·	possible solution to many of the
2:17	·	unanswered questions about the universe
2:19	·	under this Theory the weak and strong
2:21	·	nuclear forces in the electromagnetic
2:23	·	force are trapped within the membrane
2:25	·	but the gravitational force has no such
2:27	·	restriction as such much of the
2:29	·	gravitational force leaks out into the
2:31	·	bulk this accounts for why it is so
2:34	·	comparatively weak similarly other
2:35	·	membranes could exist next to us which
2:37	·	also influence the gravitational force
2:39	·	there could be other universes Trapped
2:41	·	In Their Own own membranes only a
2:43	·	microscopic distance away from ours but
2:45	·	because they could exist in spatial
2:46	·	Dimensions that are completely
2:48	·	imperceptible to us we would have no
2:51	·	idea that they were even there it is
2:54	·	regarded as one of the more elegant
2:56	·	solutions for the hierarchy problem and
2:59	·	experiments have been designed to try
3:00	·	and prove the existence of large extra
3:02	·	Dimensions thus far these have not
3:04	·	yielded any results other than to
3:06	·	constrain what the extra Dimensions
3:08	·	could actually be then again because we
3:10	·	are trying to test for extra spatial
3:12	·	Dimensions that we don't actually know
3:14	·	how to perceive detecting evidence of
3:16	·	their existence may prove to be more
3:18	·	complicated than we realized
	·	Gravity may be wrong
3:21	·	gravity may be wrong
3:25	·	okay once again we find ourselves faced
3:28	·	with the issue of gravity the
3:29	·	gravitational force was naturally the
3:31	·	first of the four forces that humans
3:33	·	discovered if you drop something it
3:35	·	falls down seems pretty straightforward
3:38	·	however of the four natural forces
3:40	·	gravity is the one we actually
3:42	·	understand the least we do have a pretty
3:44	·	good idea of how gravity works or at
3:46	·	least how we think it works despite the
3:48	·	hierarchy problem presented by it being
3:50	·	so many orders of magnitude weaker than
3:52	·	the other forces however we have seen
3:54	·	other issues related to our
3:56	·	understanding of gravity as well one
3:58	·	such problem is the speed at which
3:59	·	celestial bodies move we can observe
4:01	·	galaxies rotating much faster than they
4:03	·	should be able to or we could see
4:05	·	galaxies traveling away from us at
4:06	·	speeds far exceeding what should even be
4:09	·	possible scientists have proposed a
4:11	·	solution to this dilemma in the form of
4:14	·	Dark Matter dark matter is everywhere in
4:16	·	the universe accounting for roughly 85
4:18	·	percent of all matter it is six times
4:20	·	more abundant than the visible matter
4:22	·	that we're familiar with this dark
4:24	·	matter and the gravity exerted by its is
4:26	·	the reason we see objects moving in ways
4:28	·	that would otherwise be impossible to
4:30	·	explain however Dark Matter does not
4:33	·	interact with the electromagnetic force
4:34	·	this means it does not absorb reflect or
4:37	·	emit light making it completely
4:39	·	invisible and well that's how it got its
4:42	·	name the only problem is that because
4:44	·	it's invisible we have no proof that
4:46	·	dark matter actually exists the only
4:48	·	proof for the existence of dark matter
4:50	·	is the gravitational effect that it has
4:52	·	on other objects throughout the Universe
4:54	·	now so you may have noticed that it's a
4:56	·	bit of a logical problem there the only
4:58	·	proof we have the Dark Matter exists is
5:00	·	the gravitational effect that it has but
5:02	·	Dark Matter was proposed as a
5:05	·	theoretical solution for gravitational
5:07	·	effects that we couldn't otherwise
5:10	·	explain it somewhat circular reasoning
5:12	·	there which is why experiments like
5:14	·	those at the Large Hadron Collider hope
5:16	·	to provide more concrete proof for the
5:18	·	existence of Dark Matter however there
5:22	·	is another possible solution it could be
5:24	·	wrong notice about dark matter
5:26	·	but about gravity itself in fact we
5:29	·	already know that the current series of
5:31	·	gravity are wrong and this isn't the
5:33	·	first time that we've made that
5:34	·	Discovery gravity is put forth by Isaac
5:37	·	Newton worked great for a while he
5:39	·	described gravity as an attractive Force
5:40	·	but there were some problems for example
5:42	·	Mercury's orbit moved closer to the Sun
5:44	·	at a faster rate than Newton's equations
5:46	·	predicted Einstein's general relativity
5:48	·	solved this problem and changed our
5:50	·	understanding of gravity rather than
5:51	·	being an attractive Force Einstein saw
5:54	·	gravity as warping space-time around an
5:57	·	object thus creating a well that other
6:00	·	things would fall towards this new
6:02	·	understanding remained consistent with
6:03	·	everything that was expected from
6:05	·	Newtonian physics while also correcting
6:07	·	issues in the areas are Newton's
6:09	·	formulas didn't work unfortunately
6:11	·	general relativity also breaks down as
6:13	·	well we just aren't exactly sure where
6:15	·	we know that at some point within a
6:17	·	black hole that Einstein's theory stops
6:20	·	working and research is currently
6:21	·	working to figure out where exactly once
6:25	·	we know the exact point where breaks
6:27	·	down we may be able to figure out
6:28	·	exactly what was wrong until that
6:31	·	happens it's hard to say exactly what
6:33	·	the fate of gravity will be perhaps our
6:35	·	new understanding of the gravitational
6:36	·	force will still require the existence
6:39	·	of dark matter or perhaps we will learn
6:41	·	the double Leafs about gravity were just
6:43	·	so fundamentally flawed that dark matter
6:46	·	is no longer necessary to reconcile our
6:49	·	expectations with reality
	·	Speed of light may once have been faster
6:53	·	the speed of light may once have been
6:55	·	faster
6:57	·	if you've ever taken a physics class you
6:59	·	undoubtedly know that the speed of light
7:01	·	in a vacuum is 300 000 kilometers a
7:03	·	second and that is the fastest that
7:05	·	anything in the universe can possibly
7:07	·	travel at colder temperatures light
7:09	·	moves more slowly not because the
7:11	·	temperature itself but because colder
7:13	·	temperatures make air more dense and
7:15	·	light travels more slowly through denser
7:17	·	objects but what if this worked in the
7:21	·	other direction as well it's hard to
7:23	·	imagine it being hot enough for a vacuum
7:25	·	to somehow become even more of a vacuum
7:28	·	however one Theory suggests that the
7:30	·	origins of the universe it was so hot
7:31	·	that light essentially underwent a phase
7:33	·	change like water turning into steam as
7:36	·	a result of this change light was able
7:38	·	to far exceed its current maximum speed
7:40	·	approaching effectively infinite speed
7:43	·	this theory was proposed as an
7:45	·	alternative to inflation Theory the most
7:47	·	commonly accepted explanation for the
7:49	·	Horizon problem in Cosmic microwave
7:52	·	background or CMB The Horizon problem is
7:54	·	that the temperature across the universe
7:56	·	is even which should definitely not be
7:59	·	possible likewise CMB is the oldest
8:01	·	measurable light in the universe having
8:02	·	been emitted out 300 000 years after the
8:05	·	big bang and the light is equivalent
8:08	·	everywhere the consistency of CMB shows
8:11	·	that the temperature across the universe
8:12	·	should have been the same but this
8:13	·	doesn't make logical sense as the
8:15	·	universe was so big that light and
8:18	·	thusly heat should not have reached all
8:20	·	of it the inflation theory proposes that
8:23	·	a fraction of a second after the big
8:25	·	bang the universe underwent a massive
8:27	·	exponential expansion outward that
8:29	·	lasted for only a fraction of a second
8:31	·	as space-time expanded exponentially the
8:34	·	existing light and heat was carried with
8:36	·	it and then propagated as normal it's an
8:38	·	elegant solution that answers a lot of
8:40	·	problems and because it only happened
8:42	·	once billions of years ago it's also
8:44	·	well completely untestable in addition
8:47	·	to being an untestable Theory it raises
8:50	·	the question of why why would this have
8:52	·	happened why for only such a short time
8:55	·	and why never again these these are
8:57	·	questions that we just don't have
9:00	·	answers for because the untestable and
9:01	·	difficult to rationalize nature of
9:03	·	inflation the alternate theory was
9:05	·	proposed that extremely high
9:06	·	temperatures allowed light to travel in
9:08	·	incredible speeds following the Big Bang
9:09	·	This would run contrary to Weinstein's
9:12	·	theory of special relativity but it does
9:13	·	hold one advantage over inflation Theory
9:15	·	the physicists who proposed the most
9:18	·	recent iteration of the theory believed
9:20	·	that they could actually prove it it is
9:22	·	believed that in the near future the
9:23	·	idea of a previously variable speed of
9:26	·	light could be tested if so this Theory
9:28	·	will live or die by the result of those
9:31	·	experiments it's impossible to predict
9:32	·	what the results would be but if testing
9:35	·	were to confirm this Theory it would
9:36	·	require rethinking much of what we
9:38	·	believe we know about physics
	·	Adolf Hitler could make first contact with aliens
9:40	·	Adolf Hitler could make first contact
9:42	·	with extraterrestrials
9:45	·	we're not proposing that Hitler at the
9:47	·	age of 133 is alive and well in South
9:49	·	America and will soon be launching
9:51	·	himself into space to make first contact
9:52	·	with an alien civilization though such a
9:55	·	conspiracy theory probably does exist
9:57	·	because of course it does instead we're
9:59	·	going to be looking at an idea first
10:01	·	presented by Carl Sagan in his 1985
10:03	·	novel contact which was later adapted
10:06	·	into a 1997 film starring Jodie Foster
10:09	·	Humanity has been broadcasting messages
10:11	·	into space for decades though much of it
10:14	·	wasn't intentional most signals that
10:15	·	were transmitted over the airwaves were
10:17	·	either at too lower frequency or too low
10:20	·	power to escape Earth's ionosphere
10:22	·	however as Sagan put forth the First
10:24	·	Signal broadcast that was powerful
10:25	·	enough to escape Earth's atmosphere and
10:27	·	travel into outer space was the opening
10:28	·	ceremony of the 1936 Olympic Games in
10:31	·	Berlin this could make Hitler's opening
10:32	·	speech at the Olympics and alien
10:34	·	civilizations first encounter with
10:36	·	humans though contact was a fiction
10:39	·	novel it was based in hard science many
10:41	·	scientists dispute the claim that this
10:43	·	will be the first transmission received
10:44	·	by extra Industrials but they do admit
10:47	·	that yeah
10:48	·	it is actually possible although the
10:51	·	signal was relatively weak compared to
10:52	·	messages that have been beamed into
10:54	·	space with more clear intent it could
10:57	·	easily travel hundreds if not thousands
10:59	·	of light years into space though
11:00	·	scientists believe that because of the
11:02	·	low intensity of the signal it is likely
11:04	·	to be missed they state that aliens
11:06	·	would need to be listening to the void
11:08	·	of space extremely intently in order to
11:10	·	find the signal while that is true
11:12	·	there's no reason to believe that they
11:14	·	wouldn't be doing exactly that after all
11:17	·	we certainly are the bigger obstacle
11:19	·	would be that whatever civilization were
11:21	·	to encounter this broadcast may have no
11:23	·	way to decode it they would certainly
11:25	·	recognize it as a technological
11:26	·	broadcast of some kind instead of
11:28	·	something naturally occurring but that
11:30	·	doesn't mean it would be able to
11:32	·	separate the audio and the visual
11:33	·	information from the signal and
11:35	·	reproduce the video that was being
11:37	·	broadcast around Earth it's
11:39	·	understandable that scientists would
11:41	·	want to try and debunk this Theory as
11:43	·	best as possible given the rather
11:45	·	non-controversial statement that Hitler
11:47	·	was a bad dude however there is no
11:50	·	denying that the Olympic broadcast was
11:52	·	almost certainly the first man-made
11:53	·	signal powerful enough to break through
11:55	·	the ionosphere and that if aliens are
11:58	·	looking hard enough they could find it
	·	You are a Boltzmann brain
12:01	·	you are a boltzmann brain that's the
12:04	·	heat death of the universe in 1896
12:07	·	Austrian physicist Ludwig boltzmann
12:09	·	first published a theory that tried to
12:12	·	account for why the universe wasn't as
12:14	·	chaotic as thermodynamics seemed to
12:16	·	predict that it should be thermodynamics
12:18	·	was a relatively new field at the time
12:20	·	and one of the main principles of
12:21	·	thermodynamics is that the Universe
12:23	·	tries to maximize entropy or disorder
12:27	·	the universe is over 13 billion years
12:28	·	old which means that it had a long time
12:31	·	to spiral into chaos so why then is
12:34	·	everything in the universe so organized
12:36	·	why does it follow these rigid and
12:39	·	precise rules well the field of quantum
12:41	·	physics didn't exist yet and the
12:43	·	seemingly random nature of quantum
12:45	·	particles had yet to be observed so this
12:47	·	was a pretty logical question to ask it
12:49	·	is paper boltzmann presented our
12:51	·	hypothesis the hypothesis was that even
12:53	·	after the universe had reached maximum
12:55	·	entropy also known as the heat death of
12:58	·	the universe that it would randomly
12:59	·	undergo fluctuations to a more ordered
13:01	·	State possibly creating something like
13:04	·	the universe that we see today other
13:06	·	cosmologist didn't believe this was
13:08	·	likely and the boltzmann brain was
13:10	·	proposed as a reductio and absurdum
13:12	·	argument against the theory the idea is
13:15	·	that smaller fluctuations are more
13:16	·	likely than large ones as such it is
13:18	·	more likely that the random fluctuations
13:20	·	formed a single human brain full of
13:23	·	false memories than it is to have formed
13:25	·	the entirety of our observable universe
13:28	·	it sounds like a silly idea because it
13:31	·	was intended to be like Schrodinger's
13:33	·	cat it was meant to be a ridiculous
13:36	·	argument for a century it remained a
13:39	·	ridiculous argument meant to disprove
13:41	·	Boltzmann's Theory however in 2002
13:44	·	something changed there's theories about
13:46	·	the universe and a possible Multiverse
13:48	·	became more advanced and better
13:50	·	understood the maths showed something
13:52	·	startling statistically speaking you are
13:56	·	far more likely to be a boltzmann brain
13:58	·	that randomly formed eons after the heat
14:01	·	death of the universe and was filled
14:02	·	with false memories including a belief
14:04	·	that you existed a point when the
14:06	·	universe was much younger obviously this
14:09	·	was never the goal nobody is trying to
14:11	·	prove that boltzmann brains exist
14:13	·	they're trying to prove that they don't
14:16	·	many scientists are able to Simply
14:18	·	disregard the idea as being far too
14:20	·	silly to be worth consideration but for
14:22	·	others it's a serious problem in most
14:25	·	theories of the universe it's less
14:26	·	likely that the Universe actually exists
14:28	·	as we believe it does and it's more
14:30	·	likely that everyone who believes
14:31	·	they're watching this video right now is
14:34	·	boltzmann brain that randomly formed
14:36	·	with false memories of having watched
14:39	·	this video fortunately even those that
14:42	·	view this as a problem with current
14:44	·	theories don't believe it's the reality
14:46	·	in which we're all living we just hope
14:48	·	that someday that maths is uh going to
14:52	·	agree with them
14:57	·	[Music]