0:00 as unfathomably large as the universe
0:02 already is we keep hearing from
0:04 scientists that the universe is actually
0:07 expanding but what exactly does that
0:09 mean when we think of expansion we might
0:12 picture objects moving apart in space
0:15 but in this case it's the space itself
0:17 that's
0:18 stretching galaxies are moving away from
0:21 each other not because they are
0:22 traveling through space but because the
0:24 fabric of space between them is growing
0:28 if the universe really is EXP exping
0:30 what is it expanding into is there
0:32 something beyond the universe or is
0:34 space itself
0:36 infinite join me as we find the answers
0:39 the discovery of cosmic expansion in the
0:42 early 20th century the idea of a static
0:45 unchanging Universe was widely accepted
0:48 by scientists the belief was that the
0:51 Universe had always existed as it was
0:53 with galaxies and stars fixed in place
0:57 this view started to shift when
0:59 astronomers began to look more closely
1:01 at distant
1:02 galaxies one of the key figures in this
1:04 transformation was Edwin Hubble an
1:07 American astronomer whose observations
1:09 would completely change how we
1:11 understand the
1:12 cosmos Edwin Hubble worked at the Mount
1:15 Wilson Observatory in California where
1:17 he had access to the freshly assembled
1:19 2.5 M large hooker telescope the most
1:23 powerful telescope in the world at that
1:25 time using this tool he studied the
1:28 faint distant objects in the the night
1:30 sky at first it wasn't entirely clear
1:33 whether these objects were inside our
1:35 own Milky Way galaxy or separate from it
1:38 but Hubble was able to show that many of
1:40 these faint smudges of light were
1:43 actually entire galaxies far beyond the
1:46 Milky
1:47 Way as Hubble continued his research he
1:50 noticed something extraordinary you see
1:53 when light is measured coming from
1:54 distant galaxies it is shifted toward
1:57 the red end of the spectrum this is what
1:59 a astronomers call Red shift red shift
2:03 occurs when light waves are stretched
2:05 out making them appear redder it's
2:07 similar to how the sound of a siren
2:09 changes as it moves away from you a
2:11 phenomenon known as the Doppler effect
2:14 but instead of sound it's light being
2:17 stretched this red shift suggested that
2:20 the Galaxy's Hubble was observing were
2:22 moving away from us Hubble didn't just
2:25 observe a few galaxies he looked at many
2:27 and he noticed a pattern the farther
2:30 away a Galaxy was the greater its red
2:32 shift meaning the faster it was moving
2:34 away an observation that came to be
2:36 known as Hubble's Law this was a
2:39 groundbreaking discovery it wasn't just
2:41 a few galaxies moving it seemed that all
2:44 galaxies were moving away from each
2:45 other the universe Hubble realized
2:48 wasn't static at all it was expanding if
2:51 galaxies are moving away from each other
2:54 it suggests that in the past they must
2:56 have been closer together the idea that
2:58 the Universe was expand anding led to
3:00 the theory that the Universe had a
3:03 beginning a moment when everything was
3:05 condensed into a small incredibly dense
3:08 State before expanding
3:11 outward this was the foundation of what
3:13 would later be called The Big Bang
3:16 Theory Hubble's Discovery didn't just
3:19 change astronomy it changed our entire
3:22 understanding of the universe his work
3:24 showed that the Universe wasn't Eternal
3:26 and unchanging as many had thought
3:28 instead it was Dynam DC with galaxies
3:31 constantly moving apart this led to a
3:34 new view of the cosmos one in which the
3:36 universe had a beginning and has been
3:38 expanding ever
3:40 since the expanding Universe more than
3:44 just
3:45 distance the idea of an expanding
3:48 universe doesn't just mean that galaxies
3:50 are moving away from each other through
3:52 space it's not like stars and galaxies
3:54 are racing through an empty void
3:57 traveling from one place to another in
3:59 instead the space between them is
4:01 actually stretching this is a crucial
4:04 difference because it changes how we
4:06 think about the universe and its
4:08 structure when we talk about the
4:10 expanding Universe we're talking about
4:12 space itself getting larger over
4:16 time a helpful way to imagine this is to
4:19 think of the universe as a balloon the
4:21 galaxies are like small dots on the
4:24 surface of the balloon as the balloon
4:26 inflates the surface stretches and the
4:28 dots move farther apart part not because
4:31 they are moving across the surface but
4:33 because the surface itself is
4:36 expanding this is similar to what
4:38 happens in the
4:40 universe this concept of space expanding
4:42 changes the way we visualize the
4:44 universe normally we think of space as a
4:47 kind of stage where objects like planets
4:49 stars and galaxies exist and move but in
4:52 an expanding universe space itself is
4:55 dynamic constantly stretching as a
4:58 result the father away a galaxy is the
5:01 faster it seems to be moving away from
5:03 us because more space is expanding
5:05 between us and that Galaxy this is why
5:08 galaxies that are billions of light
5:09 years away appear to be receding at
5:12 incredible
5:13 speeds one of the strange consequences
5:16 of this idea is that there are galaxies
5:19 so far away that we will never be able
5:21 to see
5:22 them the space between us and those
5:25 galaxies is expanding so quickly that
5:27 the light they emit can't reach us it's
5:31 as if the space itself is carrying them
5:33 beyond our view this means that even
5:36 though the universe is vast and full of
5:38 galaxies there are parts of it that we
5:40 will never be able to observe or
5:43 explore these regions are Beyond What's
5:46 called the observable universe the
5:48 portion of the Universe from which light
5:51 has had time to reach us since the
5:53 beginning of the
5:54 universe another interesting aspect of
5:57 the expanding universe is that the
5:59 expansion isn't something that affects
6:01 galaxies or other objects that are close
6:03 together for example the Earth and the
6:06 Sun are not being pulled apart by the
6:08 expanding space between them that's
6:11 because the expansion of the universe
6:13 only happens on the largest
6:15 scales gravity keeps objects like solar
6:18 systems and galaxies together so the
6:20 expansion is really noticeable only
6:22 between galaxies that are far apart not
6:25 within them the fact that space itself
6:28 is expanding also means that there's no
6:31 Central Point in the universe where the
6:33 expansion is happening in other words
6:36 there's no Center to the universe every
6:39 point in space is expanding and From Any
6:41 Given Galaxy it will look like all the
6:43 other galaxies are moving away this was
6:46 one of the most difficult ideas for
6:48 scientists to accept at first because it
6:51 challenges the way we think about
6:52 movement and
6:54 space in our everyday experience things
6:57 move relative to a fixed background
7:00 but in the universe the background
7:02 itself is
7:05 changing Cosmic inflation and dark
7:07 energy the force behind accelerating
7:12 expansion the story of cosmic expansion
7:14 doesn't begin with a steady stretching
7:16 of space in fact right after the big
7:19 bang the universe experienced a brief
7:21 but incredibly intense period of
7:23 expansion called inflation this
7:25 inflationary period happened in a
7:27 fraction of a second but it had a Las
7:29 impact on the universe as we see it
7:31 today in the moments following the Big
7:34 Bang the universe was a hot dense soup
7:37 of particles and energy but almost
7:39 immediately space itself began to expand
7:42 at an extraordinary rate far faster than
7:45 it is expanding today during this
7:48 inflationary period the universe Grew
7:50 From something smaller than an atom to
7:52 something that spanned light years all
7:54 in less than a second this rapid
7:57 expansion smoothed out any irre
7:59 singularities in the universe making it
8:01 remarkably uniform while also creating
8:04 tiny fluctuations in density these
8:07 fluctuations would later become the
8:09 seeds for galaxies and
8:11 stars without inflation the universe as
8:15 we know it might never have formed in a
8:17 way that could support life inflation
8:20 spread everything out making the
8:22 universe large and mostly homogeneous
8:25 with slight variations that allowed for
8:27 the formation of galaxies and other stru
8:30 structures this brief period set the
8:32 stage for the slower expansion that
8:34 followed leading to the universe's
8:36 current size and shape while the
8:39 expansion rate slowed down after the
8:41 inflationary period scientists made a
8:44 surprising discovery about its more
8:46 recent Behavior the universe's expansion
8:49 is not just continuing it's speeding up
8:53 this was a shocking finding because most
8:55 scientists had expected the expansion to
8:57 slow down over time due to the
9:00 gravitational pull of galaxies and other
9:03 matter the discovery that the universe's
9:05 expansion is accelerating came from
9:08 observing distant Supernova which are
9:10 massive explosions that occur when
9:12 certain types of stars die in the late
9:16 1990s two teams of astronomers studied
9:19 these supern noi to measure how fast the
9:21 universe was expanding in the past
9:23 compared to today to their surprise they
9:26 found that distant Supernova were
9:28 fainter than expected
9:30 suggesting that the galaxies they were
9:31 in were farther away than they should be
9:34 if the universe's expansion was slowing
9:37 down this meant that something was
9:39 causing the expansion to speed up not
9:41 slow down the force responsible for this
9:44 acceleration has been named Dark Energy
9:47 but it remains one of the biggest
9:49 mysteries in science Dark Energy makes
9:52 up about 70% of the universe's total
9:55 energy yet we don't know exactly what it
9:58 is scientists only know that it seems to
10:01 be acting like an invisible Force that
10:03 counteracts gravity pushing galaxies
10:06 apart at an ever increasing rate unlike
10:09 normal matter or even Dark Matter Dark
10:12 Energy doesn't Clump together instead it
10:15 seems to be evenly distributed
10:17 throughout space affecting the Universe
10:19 on a grand
10:21 scale understanding dark energy is one
10:23 of the most pressing challenges in
10:25 cosmology it plays a major role in
10:27 shaping the future of the universe but
10:29 its nature remains elusive one
10:32 possibility is that dark energy is a
10:35 property of space
10:36 itself according to this idea as space
10:39 expands more space is created and with
10:42 it more dark energy this would mean that
10:45 the expansion of the universe feeds into
10:48 itself with dark energy growing stronger
10:51 as the universe grows
10:52 larger another theory suggests that dark
10:55 energy might be related to something
10:57 called the cosmological constant a
10:59 concept introduced by Albert Einstein in
11:01 his equations of general
11:03 relativity initially Einstein added the
11:06 cosmological constant to his equations
11:08 to keep the universe static because at
11:11 the time the idea of an expanding
11:13 Universe hadn't been discovered yet
11:16 after Hubble's observation showed that
11:18 the Universe was expanding Einstein
11:20 abandoned the cosmological constant
11:23 calling it his biggest blunder but the
11:26 discovery of dark energy has brought the
11:28 concept back back into the spotlight
11:31 some scientists now think that the
11:32 cosmological constant might represent a
11:35 form of dark energy something that is
11:37 built into the fabric of space
11:40 itself the presence of dark energy
11:42 raises many questions about the ultimate
11:44 fate of the
11:46 universe if the expansion of the
11:48 universe keeps accelerating what will
11:50 happen in the distant future will the
11:53 universe experience a big freeze where
11:56 galaxies move so far apart that stars
11:58 eventually burn out and the universe
12:01 becomes a cold dark place or will there
12:04 be a big rip where the acceleration of
12:07 expansion becomes so extreme that even
12:09 galaxies stars and atoms are torn
12:13 apart these ideas remain speculative but
12:17 they illustrate the profound impact that
12:19 dark energy could have on the long-term
12:21 evolution of the universe the universe's
12:24 rate of expansion a changing constant
12:29 the expansion of the universe has not
12:31 been a constant steady process over
12:34 billions of years the rate at which
12:36 space stretches has changed early in the
12:38 universe's history right after the big
12:41 bang and the inflationary period the
12:43 universe expanded incredibly rapidly
12:46 after inflation ended the expansion
12:48 continued but at a much slower Pace
12:52 Gravity the force that pulls matter
12:54 together was at work trying to slow the
12:56 expansion down for a long time this
12:59 balance between the initial outward
13:01 force from The Big Bang and the inward
13:03 pull of gravity shaped the way the
13:06 universe
13:07 evolved to understand the rate of the
13:09 universe's expansion astronomers measure
13:12 a value known as the Hubble constant the
13:15 Hubble constant tells us how fast
13:17 galaxies are moving away from each other
13:19 depending on how far apart they are it's
13:22 a key number in cosmology because it
13:24 helps scientists determine the age size
13:27 and future of the universe
13:29 the Hubble constant is measured in km/s
13:32 per megap Parc a megap Parc is a unit of
13:35 distance used by astronomers equal to
13:37 about 3.26 million light years so if a
13:41 galaxy is 1 MEAP Parc away the Hubble
13:44 constant tells us how fast it's moving
13:46 away from us in kilom per second the
13:49 farther away the Galaxy the faster it's
13:51 moving and the Hubble constant helps
13:54 quantify that
13:55 relationship measuring the Hubble
13:57 constant requires ACC Cate measurements
13:59 of both the distance to galaxies and how
14:02 fast they're moving away from us one of
14:04 the main ways astronomers measure the
14:06 distance to far away galaxies is by
14:09 using a type of star called a keiid
14:12 variable sehid variables are stars that
14:15 pulsate growing brighter and dimmer over
14:17 time the important thing about these
14:20 stars is that their brightness changes
14:22 in a regular pattern and the period of
14:24 this pulsation is directly related to
14:27 their true brightness
14:29 by comparing aide's actual brightness to
14:32 how bright it appears to us on Earth
14:34 astronomers can calculate how far away
14:36 it is once the distance to a Galaxy is
14:40 known astronomers can measure how fast
14:42 it's moving by looking at the red shift
14:44 of its light as galaxies move away from
14:47 us their light gets stretched to longer
14:50 redder
14:51 wavelengths the amount of red shift
14:54 gives a clue to the Galaxy
14:56 Speed with both the distance and the the
14:59 speed of a galaxy in hand astronomers
15:01 can determine the Hubble constant while
15:04 the idea behind measuring the Hubble
15:06 constant is straightforward the actual
15:09 value has been tricky to pin down over
15:12 the years different teams of astronomers
15:14 have come up with slightly different
15:16 measurements this has led to what's
15:18 known as the Hubble tension a scientific
15:21 debate about the exact value of the
15:23 Hubble constant there are two main
15:26 methods used to calculate the Hubble
15:28 constant and they don't quite agree with
15:30 each other one method involves measuring
15:33 the distances to galaxies and their red
15:35 shifts using objects like cified
15:38 variables and supern noi as distance
15:40 markers this is the more direct method
15:43 based on observing galaxies relatively
15:45 close to us and it gives scientists a
15:47 Hubble constant of about 73 km/s per
15:51 megap Parc another method uses data from
15:54 the early Universe particularly from the
15:57 cosmic microwave background or
15:59 CMB the CMB is the faint Afterglow of
16:03 the big bang a kind of snapshot of the
16:05 universe when it was just 380,000 years
16:08 old by analyzing the patterns in the CMB
16:11 scientists can calculate how fast the
16:13 universe was expanding shortly after the
16:15 big bang and then use models of cosmic
16:18 Evolution to estimate the Hubble
16:20 constant
16:21 today however these two methods don't
16:23 give exactly the same answer
16:26 measurements from the CMB suggest a
16:28 slightly lower value for the Hubble
16:29 constant about 67 km/s per megap Parc
16:34 this difference between the two
16:35 measurements may seem small but it's
16:38 significant enough to raise questions if
16:41 our understanding of the universe's
16:42 expansion was complete both methods
16:45 should give the same result the fact
16:47 that they don't suggest that something
16:49 might be missing from our current models
16:51 of the
16:52 universe one possibility is that there
16:55 is some unknown aspect of physics that
16:57 we haven't yet discovered
16:59 our models of the universe are built on
17:01 certain assumptions such as the
17:03 properties of dark energy dark matter
17:06 and the behavior of
17:07 gravity if any of these assumptions are
17:10 slightly off it could explain the
17:12 difference in the measurements for
17:14 example if Dark Energy doesn't behave
17:16 exactly as we think it could affect the
17:19 expansion rate in ways we haven't
17:21 accounted for it might also be that the
17:24 Universe contains some form of new
17:26 exotic matter or energy that we haven't
17:29 detected yet this new substance might
17:32 have influenced the early Universe in
17:34 ways that aren't reflected in the nearby
17:36 Universe if such a force existed it
17:39 could have impacted the rate of
17:41 expansion in the past leading to
17:43 different results when we try to compare
17:45 the early Universe with the present day
17:48 Universe another idea is that there
17:50 could be a change in how gravity works
17:53 over vast
17:55 distances Einstein's theory of general
17:57 relativity has been been incredibly
17:59 successful in describing how gravity
18:01 works on smaller scales like within our
18:04 solar system or even within
18:07 galaxies but we've never directly tested
18:09 how gravity behaves on the largest
18:11 scales of the
18:13 universe If gravity Works a little
18:15 differently across Cosmic distances it
18:18 could influence the expansion rate in
18:19 ways we don't fully understand yet some
18:22 scientists have suggested modifications
18:24 to general relativity that could account
18:27 for this to make things more complicated
18:30 there's the question of whether the
18:31 Hubble tension is a real problem or just
18:34 an issue with our
18:35 measurements measuring distances in
18:38 space is extremely challenging and it's
18:41 possible that the discrepancy arises
18:43 from subtle errors in our observations
18:45 or
18:46 calculations for example some
18:49 researchers have questioned whether we
18:50 fully understand the properties of seed
18:53 variables or supern noi even a small
18:56 error in how we calculate their true
18:58 brightness could throw off our distance
19:00 measurements and by extension our
19:03 estimate of the Hubble
19:05 constant likewise the analysis of the
19:08 cmbb relies on complex models of how the
19:11 universe evolved in its earliest moments
19:14 if there's an error in those models it
19:16 could affect the predicted value of the
19:18 Hubble constant some researchers are
19:20 revisiting the assumptions built into
19:22 these models trying to determine if
19:25 anything was missed or
19:26 misinterpreted as the universe has has
19:28 expanded over time the rate of expansion
19:31 has changed in the early Universe
19:34 gravity played a significant role in
19:36 slowing down the expansion galaxies were
19:38 closer together and their gravitational
19:41 pull on one another was Stronger over
19:44 time as the universe expanded the
19:47 galaxies moved farther apart and the
19:49 force of gravity weakened when the
19:52 universe was about 9.8 billion years old
19:55 around 4 billion years ago the expansion
19:58 rate started speeding up again driven by
20:00 dark energy as new technologies become
20:03 available astronomers hope to get closer
20:06 to the truth and so the search for an
20:08 accurate measurement of the Hubble
20:10 constant
20:11 continues new telescopes and
20:13 observatories like the James web Space
20:16 Telescope are helping astronomers refine
20:18 their measurements and get closer to a
20:21 definitive
20:23 value expansion and the limits of
20:26 gravity the expansion of the Universe
20:29 raises questions about how gravity one
20:31 of the fundamental forces of nature
20:34 interacts with the stretching of space
20:36 on the largest scales the universe is
20:39 expanding and galaxies are moving apart
20:41 as space itself grows but on smaller
20:45 scales like within galaxies or Galaxy
20:47 clusters gravity appears to hold things
20:50 together these two forces expansion and
20:53 gravity are constantly at play shaping
20:56 the structure of the cosmos in ways that
20:58 con seem
20:59 contradictory gravity as described by
21:01 Einstein's theory of general relativity
21:04 is the force that pulls objects together
21:07 it's responsible for the orbits of
21:08 planets around Stars the formation of
21:11 galaxies and the clustering of galaxies
21:13 into larger
21:14 structures without gravity the universe
21:17 would be a far more chaotic place with
21:20 matter spread out randomly rather than
21:22 grouped into Stars galaxies and Galaxy
21:25 clusters gravity works because Mass ends
21:28 the fabric of SpaceTime pulling objects
21:31 toward each other the more mass an
21:33 object has the stronger its
21:34 gravitational pull at the same time the
21:38 universe is expanding driven by the
21:40 stretching of space itself galaxies are
21:43 not moving through space like cars on a
21:45 highway instead space is expanding
21:48 between them carrying them farther apart
21:51 this expansion is happening on the
21:53 largest scales affecting galaxies and
21:56 Galaxy clusters that are millions or
21:58 billions of light years away from each
22:00 other but within smaller gravitationally
22:03 bound systems like galaxies the
22:05 expansion of the universe seems to have
22:08 little to no effect this is because the
22:11 force of gravity is much stronger on
22:13 smaller scales than the effects of
22:15 cosmic
22:16 expansion within a Galaxy for example
22:19 the mass of stars planets and dark
22:21 matter creates a strong gravitational
22:23 field that keeps everything bound
22:26 together the expansion of space is so
22:28 weak on these scales that it's
22:30 essentially cancelled out by the pull of
22:32 gravity this is why we don't see
22:34 galaxies themselves expanding or Stars
22:37 drifting apart gravity holds them in
22:40 place in fact the expansion of the
22:42 universe is only noticeable when looking
22:45 at objects that are very far away from
22:47 each other on scales of millions or
22:49 billions of light years for example the
22:53 Milky Way galaxy and its neighboring
22:55 Galaxy Andromeda are not moving apart
22:58 due to Cosmic expansion in fact they are
23:02 on a collision course pulled together by
23:04 their Mutual gravitational attraction
23:07 the gravitational force between them is
23:10 strong enough to overcome the expansion
23:11 of space in their local region this is
23:14 why the expansion of the universe is
23:16 often described as a phenomenon that
23:18 happens on the cosmic scale meaning the
23:21 largest scales we can observe even
23:24 within Galaxy clusters where hundreds or
23:26 thousands of galaxies are grouped
23:28 together
23:29 gravity is still the dominant
23:31 Force Galaxy clusters are some of the
23:33 largest structures in the universe held
23:35 together by gravity while the space
23:38 between the Clusters is expanding the
23:40 galaxies within a cluster remain bound
23:43 to each other orbiting around a Common
23:45 Center of mass over time the expansion
23:48 of the universe will pull Galaxy
23:50 clusters farther apart but within the
23:53 Clusters themselves gravity keeps the
23:55 galaxies together if the universe
23:58 continues to expand at an accelerating
24:00 rate driven by dark energy will gravity
24:03 eventually lose its hold even on
24:05 galaxies and Galaxy
24:07 clusters some scientists predict that if
24:10 Dark Energy becomes dominant enough it
24:12 could eventually overpower gravity
24:14 causing galaxies stars and even atoms to
24:17 be torn apart in a scenario known as the
24:19 Big Rip in this hypothetical future the
24:23 expansion of space would become so
24:24 extreme that nothing could stay bound
24:26 together and the universe would end in a
24:29 state of complete isolation and
24:32 emptiness but for now gravity continues
24:35 to hold its
24:36 own there's another aspect to this
24:39 interaction between expansion and
24:40 gravity that scientists are still trying
24:42 to understand and it has to do with dark
24:45 matter dark matter is an invisible form
24:48 of matter that doesn't interact with
24:50 light but it makes up most of the mass
24:52 in galaxies and Galaxy clusters it's
24:56 dark Matter's gravitational pull that
24:58 holds galaxies together even when their
25:00 visible Mass like stars and gas doesn't
25:04 seem to be enough to prevent them from
25:05 flying apart without Dark Matter
25:09 galaxies wouldn't have enough Mass to
25:10 create strong gravitational fields and
25:13 they would be more susceptible to the
25:14 effects of cosmic expansion the presence
25:17 of dark matter means that galaxies are
25:19 much more massive than they appear
25:22 allowing gravity to overpower the weak
25:24 pull of expansion within them making it
25:27 a crucial component in the balance
25:30 between gravity and the expanding
25:34 Universe The cosmological Horizon the
25:37 edge of what we can
25:40 see as we look out into the vastness of
25:43 space we are appearing into the distant
25:45 past light from distant galaxies takes
25:48 millions or even billions of years to
25:50 reach us and because the universe is
25:53 constantly expanding the further away we
25:56 look the older the light we see
25:58 but there is a limit to how far we can
26:00 observe a boundary known as The
26:02 cosmological Horizon this Horizon marks
26:05 the edge of what is observable to us
26:08 setting a limit on how much of the
26:09 universe we can see even though nothing
26:12 can travel faster than light through
26:14 space space itself can expand at any
26:17 speed carrying galaxies with it as a
26:20 result the light from galaxies Beyond a
26:22 certain distance gets stretched out and
26:24 redshifted until it disappears from View
26:29 Beyond this point light from distant
26:31 objects hasn't had enough time to reach
26:33 Earth and these regions remain beyond
26:35 our observational Reach This Horizon is
26:39 sometimes referred to as the observable
26:41 universe it doesn't mean that the
26:43 Universe stops Beyond this point rather
26:46 it marks the limit of our observations
26:49 there may be countless galaxies stars
26:51 and other structures Beyond the Horizon
26:54 but they are beyond our observational
26:56 reach because the light from from Those
26:58 Distant regions has not had enough time
27:01 to get here the observable universe is
27:04 just a small part of the entire universe
27:07 and we may never be able to see beyond
27:09 this Horizon even if we wait billions of
27:12 years because the universe is expanding
27:14 at an accelerating rate the observable
27:17 universe is constantly changing as the
27:20 universe
27:21 expands as time passes light from more
27:24 distant regions reaches us and the size
27:26 of the observable universe
27:28 grows but because of the acceleration in
27:31 the universe's expansion some regions
27:34 that are currently visible may
27:35 eventually slip Beyond the cosmological
27:38 Horizon in the distant future galaxies
27:41 that we can see today may become
27:43 unreachable their light stretched out
27:45 and red shifted Beyond detection as the
27:47 expansion of space speeds up this means
27:51 that while the size of the observable
27:53 universe increases over time the number
27:55 of galaxies we can see May decrease as
27:58 they move beyond our view we can only
28:01 make observations within this Horizon
28:03 and everything we know about the
28:05 universe comes from the light that has
28:06 reached us but because the universe is
28:09 much larger than the observable portion
28:12 there is a vast amount of information
28:14 Beyond the Horizon that we cannot access
28:18 this includes galaxies Cosmic structures
28:21 and possibly even different regions of
28:24 the universe that are too far away for
28:26 us to ever observe
28:29 there are a few key factors that Define
28:31 The cosmological Horizon and one of the
28:33 most important is the age of the
28:36 universe the universe is around 13.8
28:39 billion years old and because light
28:42 travels at a finite speed we can only
28:44 see objects whose light has had enough
28:46 time to reach us this means that the
28:49 farthest objects we can observe are
28:51 about 13.8 billion years old however
28:55 because the universe has been expanding
28:57 during that time the actual distance to
29:00 these farthest objects is much greater
29:03 than 13.8 billion light years in fact
29:07 the current distance to the edge of the
29:09 observable universe is estimated to be
29:12 around 46 billion light years this might
29:15 seem counterintuitive but it makes sense
29:17 when we consider the expansion of
29:20 space as light from distant galaxies
29:22 travels toward us the space between us
29:25 and those galaxies stretches increasing
29:28 the distance between us and those
29:30 objects even though the light took 13.8
29:34 billion years to reach us the actual
29:36 distance to those galaxies today is much
29:38 larger due to the expansion of the
29:41 universe Beyond the Horizon what lies
29:44 beyond what we can see while the
29:46 cosmological Horizon marks the limit of
29:49 what we can observe it doesn't represent
29:51 the end of the universe beyond this
29:54 Horizon the universe likely continues
29:57 but we can never directly see or
29:59 interact with it the question of what
30:02 lies beyond the observable universe has
30:04 fascinated scientists for decades
30:07 prompting many theories and speculations
30:09 about what might exist in the vast
30:10 unreachable regions of
30:12 space one of the simplest ideas is that
30:15 Beyond the Horizon the universe is much
30:18 the same as it is within our
30:21 view this is based on the Assumption of
30:23 cosmological
30:25 homogeneity the idea that on large scale
30:28 the universe is uniform and looks the
30:30 same in every direction according to
30:33 this principle if we could somehow
30:35 appearer beyond the observable universe
30:38 we might find more galaxies stars and
30:41 Cosmic structures similar to what we see
30:44 in the regions within our
30:46 Horizon this would mean that the
30:48 observable universe is just one small
30:50 part of a much larger universe that
30:52 extends far beyond what we can
30:55 see some however speculate that the
30:58 Universe might not be uniform Beyond the
31:01 Horizon while the observable universe
31:03 appears relatively smooth and uniform on
31:06 large scales there could be variations
31:08 in the density of matter and energy
31:10 beyond what we can see some regions
31:13 could contain more galaxies and matter
31:15 While others might be emptier these
31:18 differences would be invisible to us due
31:20 to the limits of the cosmological
31:22 Horizon but they could have profound
31:24 implications for our understanding of
31:26 the universe as a whole
31:29 one theory that offers a more exotic
31:31 view of what might exist beyond the
31:33 observable universe is the concept of a
31:36 Multiverse According to some
31:38 interpretations of cosmology
31:40 particularly those involving
31:42 inflationary Theory the universe we live
31:44 in could be just one of many pocket
31:47 universes or bubbles that formed during
31:50 the early stages of cosmic
31:52 inflation in this scenario the rapid
31:55 expansion of space during inflation
31:56 created separate regions of SpaceTime
31:59 each with its own distinct
32:01 properties our observable universe would
32:04 be just one of these regions While
32:06 others lie Beyond the Horizon
32:09 inaccessible to
32:10 us these other regions could be vastly
32:13 different from the universe we know they
32:16 might have different physical laws
32:18 different constants or even different
32:20 numbers of
32:22 Dimensions the idea of a Multiverse
32:24 suggests that Beyond the Horizon there
32:27 could be entire universes with their own
32:29 unique structures where the fundamental
32:32 forces of nature behave in ways that are
32:34 completely alien to us while this idea
32:37 is speculative and difficult to test it
32:40 offers a fascinating perspective on what
32:42 might exist beyond the observable
32:45 universe even if we assume that the
32:48 Universe Beyond the Horizon is similar
32:50 to the one we can see the expansion of
32:52 the universe still affects these distant
32:55 regions in important ways as space
32:58 continues to expand galaxies Beyond the
33:00 Horizon are moving farther away from us
33:03 and the space between them is stretching
33:06 over time the distance between galaxies
33:08 in these distant regions will grow just
33:11 as it does within the observable
33:13 universe this means that even in the
33:15 farthest reaches of space the effects of
33:18 cosmic expansion are still at work
33:21 shaping the evolution of the universe
33:23 beyond our
33:25 view in the distant future the regions
33:28 Beyond the Horizon might become even
33:30 more disconnected from our observable
33:33 universe if the expansion of the
33:35 universe continues to accelerate driven
33:37 by dark energy it's possible that more
33:40 and more regions of space will move
33:42 beyond the reach of light effectively
33:44 isolating parts of the Universe from
33:46 each other in this scenario the universe
33:49 could become a fragmented place where
33:51 vast stretches of empty space separate
33:53 isolated pockets of galaxies these
33:56 regions would continue to exist but they
33:59 would be cut off from one another unable
34:01 to exchange information or interact in
34:04 any meaningful way for any observers
34:06 living in these distant regions the
34:09 universe would seem much smaller and
34:11 more isolated as the expansion of space
34:14 gradually pushes everything Beyond the
34:16 Horizon The cosmological Horizon is a
34:19 barrier that we cannot cross and the
34:21 regions Beyond it are forever hidden
34:23 from us this means that while we can
34:26 theorize about what might exist in Those
34:28 Distant regions we may never be able to
34:31 directly observe or confirm these ideas
34:34 is space itself infinite or expanding
34:37 into something Cosmic expansion causes
34:41 one to question the nature of space
34:43 itself you begin to wonder whether space
34:45 itself is infinite or if it is expanding
34:48 into something this question goes beyond
34:50 the idea of cosmic expansion and touches
34:53 on the very fabric of space and time the
34:57 universe we observe is expanding but
35:00 what does this expansion mean for the
35:01 underlying structure of space
35:03 itself is there a boundary or does space
35:06 stretch
35:07 endlessly and if space is expanding is
35:10 it doing so into some larger framework
35:13 or is the concept of expansion something
35:16 more
35:17 abstract if the universe is infinite it
35:20 has no Edge and no boundary it simply
35:23 extends forever in all
35:25 directions in this case the expansion of
35:28 the universe means that even though
35:30 space is infinite the distances between
35:33 objects in that Infinite Space are
35:35 increasing no matter how far you travel
35:38 space continues and there is no end to
35:40 the
35:41 universe this idea is difficult for us
35:44 to grasp because we're used to thinking
35:46 about things that have limits or
35:48 boundaries yet in an infinite Universe
35:51 there is no Outer Edge to speak of some
35:54 theories suggest that the Universe might
35:56 be finite but unb bounded this means
35:59 that the Universe has a certain size but
36:01 it doesn't have an edge or a boundary
36:03 that you can reach our old balloon
36:06 analogy helps here the surface of the
36:08 balloon is finite there's a limited
36:11 amount of space on the balloon surface
36:13 but it has no Edge if you travel in One
36:16 Direction long enough you could
36:17 eventually end up back where you started
36:20 much like traveling around the earth the
36:22 universe could be like this finite in
36:25 size but without any bound
36:28 where space simply
36:29 Stops Another possibility is that the
36:32 universe is expanding into something but
36:35 what could this something be in everyday
36:38 terms when we think about things
36:40 expanding we often think of them
36:42 expanding into a larger space but in the
36:46 context of the universe the expansion
36:48 doesn't work this way space itself is
36:51 expanding and it's not expanding into a
36:53 pre-existing space because space and
36:56 time are part of the universe
36:58 itself if there is something beyond the
37:00 universe we have no way of knowing what
37:02 it might be and it doesn't affect our
37:05 understanding of cosmic expansion if the
37:07 universe is a part of a much larger
37:09 Multiverse with many universes existing
37:12 side by side then the space in which our
37:14 universe exists might be part of a
37:16 larger structure but again the expansion
37:19 we observe doesn't require our universe
37:22 to be expanding into this larger
37:24 Multiverse the expansion is still the
37:26 stretching of space itself and what
37:28 might lie beyond the universe remains an
37:31 open question at the smallest scales the
37:34 fabric of space is believed to be far
37:36 from smooth according to Quantum Theory
37:40 space at the tiniest levels is thought
37:42 to be a turbulent everchanging landscape
37:44 known as quantum
37:46 foam this quantum foam represents the
37:48 fluctuations in energy that occur at
37:50 incredibly small scales where the
37:53 effects of quantum mechanics dominate
37:56 these fluctuations canuse cuse space
37:58 itself to behave unpredictably with
38:00 particles popping in and out of
38:01 existence in tiny fractions of a
38:04 second in this Quantum realm space is
38:07 not the smooth continuous entity we
38:10 experience in everyday life instead it's
38:12 full of
38:13 activity could the universe be infinite
38:16 at larger scales but fundamentally
38:18 granular or discret at the smallest
38:21 scales if so the concept of Infinite
38:24 Space becomes even more complex
38:28 while the expansion of the universe
38:30 works on vast Cosmic distances the
38:33 effects of quantum mechanics operate at
38:35 minuscule
38:36 scales some scientists have wondered
38:39 whether there might be a connection
38:40 between these two
38:41 extremes could the expansion of space
38:44 itself be influenced by Quantum
38:46 fluctuations at the smallest
38:49 scales this remains an area of active
38:52 research as scientists attempt to link
38:55 the seemingly separate Realms of quantum
38:57 mechan mechanics and Cosmic
39:00 expansion curved space could Expansion
39:03 change the shape of the
39:05 universe curvature plays a fundamental
39:08 role in the structure of the cosmos and
39:10 the shape of the universe is closely
39:12 tied to its
39:14 expansion scientists have long debated
39:16 whether the universe is flat closed or
39:19 open three different possibilities for
39:22 the curvature of space this curvature is
39:25 not something we can easily visualize Li
39:28 but it has a direct influence on how the
39:30 universe behaves on the largest scales
39:32 including its ongoing expansion the
39:35 concept of curved space comes from
39:37 Einstein's theory of general relativity
39:40 according to this Theory massive objects
39:42 like stars and galaxies warp the space
39:45 around them creating what we experience
39:47 as gravity this curvature is usually
39:50 very small on local scales like within
39:52 our solar system but on larger scales
39:55 the overall curvature of the Universe
39:57 could take on one of three forms flat
40:01 closed or open the curvature of the
40:04 universe is determined by the total
40:06 amount of mass and energy it
40:09 contains if the universe is flat it
40:12 means that space extends in every
40:14 direction without bending back on itself
40:17 in this scenario parallel lines would
40:20 remain parallel forever and the angles
40:22 of a triangle would always add up to
40:25 180° just as they do on a flat piece of
40:28 paper a flat universe implies that it
40:31 has just the right amount of mass and
40:33 energy to prevent it from either
40:35 collapsing in on itself or expanding
40:37 Forever at an accelerating rate in a
40:41 closed universe space would curve in on
40:43 itself much like the surface of a sphere
40:46 in this scenario if you traveled far
40:49 enough in One Direction you could
40:50 eventually end up back where you started
40:53 the total amount of mass and energy in a
40:55 closed Universe would be high enough
40:57 enough that its gravitational pull would
40:59 eventually cause the universe to stop
41:01 expanding and begin Contracting a closed
41:04 Universe would eventually collapse in a
41:07 big crunch where all matter and energy
41:09 are pulled back together by gravity on
41:13 the other hand an open Universe would
41:15 have negative curvature like the shape
41:17 of a saddle in an open universe space
41:21 would continue expanding forever and the
41:24 farther away galaxies are from one
41:25 another the faster they would move apart
41:29 the universe would have too little mass
41:31 and energy to ever pull itself back
41:33 together meaning it would continue
41:35 expanding Without End in an open
41:38 Universe the angles of a triangle would
41:41 add up to less than
41:43 180° and parallel lines would eventually
41:46 diverge so basically in a flat universe
41:50 expansion would slow down over time as
41:52 the mass of the universe exerts a
41:54 gravitational pull on itself in a closed
41:58 Universe the expansion would eventually
42:00 stop and reverse leading to the Big
42:03 Crunch and in an open Universe expansion
42:06 would continue indefinitely but at a
42:08 slower and slower rate as time goes on
42:12 one of the key goals of cosmology has
42:14 been to determine the shape of the
42:16 universe by studying the CMB scientists
42:20 have been able to measure the curvature
42:22 of space on large scales these
42:25 measurements suggest that the universe
42:27 is remarkably flat meaning that space
42:29 does not curve noticeably on Cosmic
42:32 scales this doesn't mean that the
42:34 universe is exactly flat but that any
42:37 curvature it might have is incredibly
42:39 small so small that it's undetectable
42:43 with current instruments however the
42:46 flatness of the universe doesn't mean
42:47 that it will expand at a steady rate
42:50 forever the discovery of dark energy has
42:53 changed our understanding of how the
42:55 universe will evolve dark energy is
42:58 causing the universe to expand faster
43:00 and faster regardless of its curvature
43:04 even if the universe is Flat Dark Energy
43:07 could lead to an Ever accelerating
43:09 expansion where galaxies move apart at
43:11 increasing speeds and space itself
43:14 continues to stretch if the universe is
43:17 flat as current evidence suggests this
43:20 means that the total density of mass and
43:23 energy in the universe is very close to
43:25 a critical value any small deviation
43:28 from this balance would have resulted in
43:30 a universe that was either closed or
43:33 open this leads to the question how did
43:36 the universe come to be so flat the
43:38 theory of cosmic inflation offers an
43:41 explanation according to this Theory
43:43 inflation stretched the universe so
43:45 rapidly and uniformly that any initial
43:48 curvature was smoothed out leaving the
43:50 universe flat on large
43:53 scales even though we live in a
43:55 seemingly flat universe
43:57 the effects of curvature could still be
43:59 present in ways we don't yet fully
44:01 understand on small scales like within
44:04 galaxies or clusters of galaxies the
44:07 curvature of space caused by gravity is
44:09 very much a
44:11 reality the gravitational pull of
44:13 massive objects warps the space around
44:15 them bending light and affecting the
44:17 motion of stars and planets this local
44:20 curvature however doesn't impact the
44:23 overall expansion of the universe in the
44:25 same way that large scale curvature does
44:28 it's also possible that the Universe has
44:31 a slight curvature that we haven't yet
44:33 detected if the universe is slightly
44:36 closed or open the effects would be so
44:38 small that they would only become
44:40 noticeable over vast distances far
44:43 beyond the reach of our current
44:46 observations future advancements in
44:48 technology and measurements might give
44:50 us a clearer picture of the universe's
44:52 curvature and how it interacts with the
44:54 ongoing expansion of space
44:59 the fate of distant galaxies where are
45:01 they going with the universe expanding
45:04 distant galaxies are moving away from us
45:06 at an ever increasing rate this
45:08 phenomenon driven by the accelerating
45:10 expansion of space means that galaxies
45:13 far from our own are receding faster and
45:15 faster over time the rate at which they
45:18 are moving away will eventually exceed
45:19 the speed of light while this might
45:21 sound counterintuitive since nothing can
45:24 travel faster than light it's important
45:26 to remember that this doesn't violate
45:28 the laws of physics it's not the
45:30 galaxies themselves that are breaking
45:32 the speed limit rather space itself is
45:35 stretching carrying these galaxies with
45:38 it this distinction is crucial for
45:41 understanding the fate of these distant
45:43 galaxies and what it means for the
45:45 future of the
45:46 universe as the space between us and
45:49 these distant galaxies expands they will
45:52 move farther away from our point of
45:55 observation at a certain point
45:57 these galaxies will recede so quickly
46:00 that their light will no longer be able
46:01 to reach us this is because the
46:04 expansion of space will outpace the
46:06 ability of light to travel across it
46:09 once that happens these galaxies will
46:11 effectively disappear from our view they
46:14 won't vanish in a literal sense they
46:16 will still exist but they will be beyond
46:19 our observational reach leaving us
46:21 isolated in a shrinking observable
46:24 universe this process is gradual and
46:27 ongoing even now there are galaxies so
46:30 far away that their light is just barely
46:32 reaching us over time these galaxies
46:35 will drift farther apart and eventually
46:38 the light they emit will be stretched to
46:39 such long wavelengths that it will be
46:42 undetectable this is a direct
46:44 consequence of the red shift effect
46:46 which occurs when light waves are
46:48 stretched by the expansion of space as
46:51 galaxies move away from us the light
46:53 they emit is stretched into longer
46:55 wavelengths shifting toward the red end
46:57 of the spectrum the faster a Galaxy
47:00 recedes the more its light is redshifted
47:03 and eventually it will be red shifted
47:05 beyond the visible spectrum becoming
47:08 invisible to even the most sensitive
47:11 telescopes in the far future billions of
47:14 years from now most galaxies will have
47:17 receded Beyond The Cosmic Horizon the
47:20 limit of the observable
47:22 universe the only galaxies that will
47:24 remain visible to us will be those
47:26 gravit ation Al bound to our own such as
47:29 the galaxies within our local group
47:32 these include the Andromeda galaxy The
47:35 Milky Way and a few smaller neighboring
47:38 galaxies because they are
47:39 gravitationally bound the expansion of
47:42 the universe does not affect them in the
47:44 same way instead they will remain
47:47 relatively close to each other and will
47:49 eventually merge into a single massive
47:51 Galaxy but beyond this small local
47:54 cluster the rest of the universe will be
47:56 lost to us with distant galaxies Fading
47:59 Into the Darkness this future where
48:01 distant galaxies are receding faster
48:04 than light and Vanishing beyond our
48:05 ability to observe them paints a picture
48:08 of increasing isolation it suggests that
48:11 the universe will become more and more
48:13 empty from our
48:15 perspective as each Galaxy crosses the
48:18 cosmic Horizon it takes with it the
48:20 information about its past leaving us in
48:23 an increasingly dark and lonely Cosmos
48:27 scientists speculate that in this
48:29 distant future any observers within our
48:31 galaxy may have no way of knowing that
48:34 there ever was a vast Universe filled
48:36 with countless
48:38 galaxies without the evidence provided
48:41 by the light from distant galaxies
48:43 future astronomers might believe that
48:45 the Milky Way or the merged Galaxy it
48:48 becomes is the entire universe as
48:51 galaxies move farther apart the chances
48:53 of interaction between them decrease
48:56 while while in the early Universe
48:58 galaxies often collided and merged
49:00 forming larger structures and triggering
49:02 bursts of star formation these events
49:05 will become less frequent as time goes
49:07 on the universe will become a quieter
49:10 more isolated place with fewer
49:12 opportunities for Galaxies to influence
49:15 each other in the far future long after
49:18 the distant galaxies have vanished
49:20 Beyond The Cosmic Horizon the universe
49:22 will be a vastly different place the
49:25 Stars within our galaxy will continue to
49:27 burn for billions of years but
49:29 eventually even they will fade the
49:32 universe will grow colder and darker as
49:35 stars die out and new ones are no longer
49:38 born this era known as the heat death of
49:41 the universe represents a state where
49:44 the universe has expanded so much that
49:46 it no longer supports the kind of active
49:49 Dynamic processes that shaped its early
49:52 Evolution could expansion alter the laws
49:54 of physics
49:56 as Cosmic expansion continues to
49:58 accelerate some wonder if it could alter
50:01 the laws of physics itself this question
50:04 challenges the assumption that the
50:05 fundamental constants of nature such as
50:08 the speed of light the strength of
50:10 gravity or the fine structure constant
50:12 remain the same throughout the history
50:14 of the
50:15 universe in most models of physics these
50:18 constants are fixed providing a stable
50:21 framework for the behavior of matter and
50:24 energy however as the universe expands
50:27 and evolves some theorists have
50:29 questioned whether this process could
50:31 gradually shift or influence the laws
50:33 that govern reality to understand this
50:36 idea it's important to recognize the
50:39 role these constants play in shaping the
50:41 universe the speed of light for instance
50:44 determines how fast information can
50:46 travel across space the gravitational
50:48 constant dictates how strongly objects
50:51 with mass attract one another the fine
50:54 structure constant governs the
50:55 interaction between light and charged
50:58 particles playing a critical role in
51:00 chemistry and the formation of matter
51:03 these values form the backbone of
51:05 physics As We Know It And even a slight
51:08 variation in any of them could lead to a
51:10 universe that looks very different from
51:12 our
51:13 own as the universe expands particularly
51:16 under the influence of dark energy space
51:19 itself is
51:21 stretching this stretching of space
51:23 affects how distances between objects
51:25 grow and how the Universe evolves on
51:27 large
51:29 scales while this expansion has a clear
51:31 impact on the arrangement and movement
51:33 of galaxies could it be possible that as
51:36 space stretches the constants governing
51:39 these interactions change ever so
51:42 slightly some have speculated that the
51:45 constants we observe today might not
51:47 have been the same in the distant past
51:50 for instance there is a possibility that
51:53 the strength of the electromagnetic
51:55 force or the gravit ational Force could
51:57 have been different in the early
51:59 Universe leading to different conditions
52:01 for the formation of stars galaxies and
52:04 other Cosmic
52:06 structures these speculations are fueled
52:09 by the idea that if the universe is
52:11 dynamic in its structure it might also
52:14 be dynamic in its underlying
52:17 laws one area where this idea gains some
52:20 attention is in the context of the fine
52:22 structure constant which governs the
52:24 strength of the electromagnetic force
52:26 Force this constant plays a crucial role
52:29 in determining how atoms interact and
52:32 how light
52:33 behaves some Studies have suggested that
52:36 the fine structure constant may have
52:38 been slightly different billions of
52:39 years ago although this remains an area
52:42 of debate if such a variation were
52:45 confirmed it would suggest that Cosmic
52:47 expansion or perhaps other Cosmic
52:49 processes might have a subtle influence
52:52 on the constants of nature if Dark
52:54 Energy behaves in ways we don't fully
52:56 understand it could introduce variations
52:59 in the fundamental forces that shape the
53:01 universe some theories suggest that dark
53:04 energy could be tied to the evolution of
53:06 the cosmos in ways that might affect the
53:08 constants of nature the expansion of the
53:11 universe might also influence how we
53:13 perceive time as space stretches the
53:17 intervals between objects increase and
53:19 the wavelengths of light get longer but
53:22 could the same stretching of space
53:25 affect how time flows at a fundamental
53:28 level there are also more exotic ideas
53:32 that suggest Cosmic expansion might not
53:34 only influence the constants of nature
53:36 but could also lead to entirely new
53:38 forms of physics emerging over time some
53:41 theories propose that as the universe
53:43 continues to expand and cool the laws
53:46 governing high energy processes might
53:48 shift into new States causing
53:51 fundamental forces to change in ways
53:53 that are currently
53:54 unimaginable this could potentially lead
53:56 to phase transitions in the universe
53:59 where the laws of physics reorganize
54:01 themselves under new conditions much
54:03 like how water freezes into ice under
54:06 certain temperatures in such a scenario
54:09 the universe as we know it could
54:10 transform into a very different reality
54:13 billions or even trillions of years into
54:16 the future the impact of expansion on
54:19 Cosmic structures growing gaps in the
54:22 universe as the universe expands the
54:25 large scale structures that Define it
54:27 are also
54:28 reshaped these structures Galaxy
54:31 clusters filaments and voids are the
54:33 result of gravity pulling matter
54:35 together over billions of years forming
54:38 vast networks of galaxies interconnected
54:40 by threads of dark matter and ordinary
54:43 matter but alongside this pull of
54:45 gravity the expansion of space is
54:48 driving galaxies apart creating a cosmic
54:51 tug OFW between attraction and
54:54 separation over time this expansion is
54:57 creating larger gaps between Cosmic
54:59 structures stretching the fabric of the
55:02 universe and transforming its overall
55:04 shape on the largest scales the universe
55:07 is organized into a webike structure
55:09 called The Cosmic web this web is
55:12 composed of long filaments of galaxies
55:15 which connect denser regions known as
55:17 Galaxy
55:18 clusters between these clusters and
55:20 filaments are enormous empty spaces
55:23 called voids where very few galaxies are
55:25 found
55:26 the expansion of the universe is not
55:28 uniform while galaxies within clusters
55:31 remain bound together by gravity the
55:34 space between these clusters is
55:36 expanding causing the voids to grow
55:38 larger and the filaments to
55:41 stretch over time the galaxies Within
55:44 These filaments are pulled away from one
55:46 another this leads to a process called
55:49 Cosmic Drift where galaxies that were
55:51 once relatively close neighbors become
55:54 more and more isolated
55:56 this increasing separation between
55:58 galaxies means that interactions such as
56:01 Galaxy mergers which were common in the
56:03 early Universe become less frequent the
56:07 expansion of the universe is effectively
56:10 quieting The Cosmic Landscape making it
56:13 harder for Galaxies to collide exchange
56:16 matter or influence each other through
56:19 gravitational
56:20 interactions the most striking effect of
56:23 expansion on Cosmic structures is the
56:25 growth of the voids these vast empty
56:29 regions between Galaxy clusters are
56:31 getting larger as the universe expands
56:34 pushing galaxies farther apart and
56:36 making the large scale structure of the
56:38 universe more
56:39 fragmented in the distant future these
56:42 voids will dominate the observable
56:44 universe with Galaxy clusters appearing
56:47 as isolated
56:48 Islands within Galaxy clusters gravity
56:51 is strong enough to counteract the
56:53 expansion of the
56:54 universe galaxies in and clusters remain
56:57 gravitationally bound to one another and
56:59 while space is expanding these galaxies
57:02 don't drift apart in the same way as
57:04 galaxies in less dense regions of space
57:07 however beyond the boundaries of these
57:09 clusters the expansion is Unstoppable in
57:12 the current universe galaxy clusters are
57:14 still connected by filaments of galaxies
57:17 but these connections are weakening over
57:19 time the expansion of space will stretch
57:21 these filaments to the point where they
57:23 can no longer hold together and the
57:25 Galaxy within them will drift apart the
57:28 Clusters themselves will remain intact
57:30 for now held together by their own
57:33 gravitational pull but the distances
57:35 between clusters will continue to grow
57:38 eventually these clusters will become
57:40 increasingly separated isolated in an
57:43 expanding sea of voids with voids
57:46 expanding fewer galaxies will be visible
57:48 from any given point in the universe the
57:51 light from distant galaxies will be
57:53 stretched and redshifted to the point
57:54 where it becomes undet detectable this
57:57 means that the observable universe will
57:59 shrink not in size but in the number of
58:02 galaxies that can be
58:04 seen in the far future observers in any
58:07 Galaxy may only be able to see the few
58:10 galaxies within their own cluster with
58:12 the rest of the universe disappearing
58:14 Beyond The Cosmic
58:16 Horizon and the processes that have
58:18 shaped galaxies such as merges star
58:21 formation and the exchange of gas and
58:23 dust will slow down as the universe
58:27 ages in the early Universe galaxies
58:30 formed from the collapse of gas and dark
58:32 matter within small regions of space but
58:35 as the universe expands the density of
58:37 matter decreases making it harder for
58:40 new galaxies to form the existing
58:43 galaxies will continue to evolve but the
58:46 formation of new galaxies from
58:47 primordial gas clouds will become
58:50 increasingly rare eventually the
58:53 universe will reach a point where no new
58:55 galaxies are forming and the existing
58:57 ones will continue to drift
58:59 apart the gaps between Cosmic structures
59:02 will grow so large that even the light
59:05 from distant galaxies will no longer be
59:07 able to bridge the distances leaving us
59:10 in a universe that is increasingly dark
59:13 and
59:14 quiet expansion and the flow of
59:18 time time and space are intertwined in
59:21 the fabric of the universe and many
59:23 wonder if the expansion of space could
59:25 somehow affect the flow of time while
59:27 time is often thought of as a constant
59:29 and unchanging March forward the
59:32 relationship between time space and the
59:35 universe's expansion hints that time
59:38 might not be as fixed as it
59:41 seems in the framework of general
59:43 relativity time and space are part of a
59:46 single entity known as
59:49 SpaceTime this means that what happens
59:51 to space whether it's bending around
59:54 massive objects like stars or stretching
59:56 during the universe's expansion can have
59:59 an effect on time as well as the
60:02 universe grows the distances between
60:04 objects increase and the Very fabric of
60:07 SpaceTime stretches along with it but
60:10 does this stretching influence the way
60:12 we experience time the short answer is
60:15 that for most of us time on a daily
60:17 level doesn't seem to change due to
60:18 Cosmic expansion we measure time with
60:21 clocks which tick along at a steady Pace
60:24 the Earth orbits the Sun and the sun
60:27 rises and sets on schedule in the
60:30 context of our local environment we
60:32 don't feel the effects of the universe's
60:34 expansion directly this is because on
60:37 small scales like the ones we experience
60:39 in everyday life the force of gravity
60:42 dominates keeping things like planets
60:44 stars and galaxies bound together time
60:47 flows normally Within These
60:49 systems however on Cosmic scales where
60:52 the distances between galaxies are
60:54 immense and space itself is expanding
60:57 the relationship between time and
60:59 expansion becomes more complex as space
61:02 stretches so does the light that travels
61:05 through it leading to the red shift we
61:07 observe in distant
61:09 galaxies this red shift doesn't just
61:11 stretch the light waves it also affects
61:14 how we perceive time from distant
61:16 objects light from galaxies that are far
61:19 away doesn't just appear redder it also
61:21 arrives more slowly the farther away a
61:24 galaxy is the the more time seems to
61:26 slow down from our
61:28 perspective events that unfold in those
61:31 distant galaxies appear to take longer
61:33 as if time itself is stretched along
61:35 with
61:36 space this phenomenon known as time
61:39 dilation is a direct result of the
61:41 expansion of the universe it means that
61:44 when we observe a distant Supernova or a
61:46 Galaxy at the far edges of the
61:49 observable universe we're seeing time
61:51 unfold at a slower rate than we do here
61:53 on Earth the expansion of space
61:56 stretches not only the light waves but
61:58 also the duration of events making
62:01 distant Cosmic occurrences seem to
62:03 happen more slowly some theories suggest
62:07 that as the universe continues to expand
62:09 time itself could be affected in ways we
62:12 don't yet fully understand the
62:14 accelerated expansion may lead to a
62:16 universe where time behaves differently
62:19 on Cosmic scales potentially altering
62:21 the fundamental way we experience and
62:24 measure it one area of speculation
62:27 involves the possibility that the
62:29 expansion could lead to a big freeze or
62:31 heat death of the universe where all the
62:34 Stars Burn Out galaxies drift apart and
62:37 the universe becomes a cold dark place
62:41 in such a future with no stars to Mark
62:43 the passage of time the very concept of
62:45 time might lose its
62:47 meaning if nothing is happening if no
62:50 processes are unfolding then time in a
62:52 sense could come to a
62:54 standstill the this would be an ultimate
62:57 consequence of the universe's expansion
62:59 where not only space but also time
63:02 itself might seem to fade away as Cosmic
63:05 activity winds down general relativity
63:08 tells us that time is not an absolute
63:11 unchanging quantity instead time is
63:14 relative it can flow at different rates
63:16 depending on the gravitational field and
63:18 the motion of objects for example clocks
63:22 tick more slowly near massive objects
63:24 like black holes due to their strong
63:26 gravitational pull this phenomenon is
63:30 called gravitational time dilation and
63:32 it's been experimentally confirmed such
63:35 as by measuring time differences between
63:37 clocks on the ground and those on
63:38 airplanes or
63:40 satellites could something similar
63:42 happen on a cosmic scale with the
63:44 expansion of space affecting the passage
63:46 of time so far the answer isn't clear
63:50 the accelerated expansion driven by dark
63:53 energy does influence how we observe
63:55 time at Great distances but how this
63:58 might affect the flow of time in the
63:59 universe's distant future remains an
64:02 open question some physicists have even
64:05 speculated that time itself could be
64:07 emergent that is that time as we
64:10 experience it might be a result of
64:12 deeper processes tied to the fundamental
64:14 structure of the
64:16 universe the limits of expansion what
64:20 happens at the smallest scales it's easy
64:22 to focus on the large scale when
64:24 considering Cosmic expans expansion but
64:26 what happens at the smaller scales does
64:29 the expansion of the universe have any
64:31 impact on the quantum world where
64:33 particles like electrons protons and
64:35 photons exist at its core the expansion
64:39 of the universe means that the space
64:40 between galaxies and Galaxy clusters is
64:43 increasing however within galaxies and
64:46 especially within smaller structures
64:48 like stars planets and atoms the
64:50 expansion of space doesn't seem to have
64:52 a noticeable effect the forces that bind
64:56 these objects together such as gravity
64:58 electromagnetism and the strong nuclear
65:01 force are far stronger than the effects
65:03 of cosmic expansion at these smaller
65:06 scales these forces essentially hold
65:09 things together keeping atoms intact and
65:12 planets in orbit even as the universe
65:15 grows larger around them on the quantum
65:18 level particles are held together by the
65:21 fundamental forces of nature such as the
65:23 electromagnetic force between electrons
65:25 and protons or the strong nuclear force
65:28 that binds quarks inside protons and
65:31 neutrons these forces are incredibly
65:33 powerful compared to the weak effects of
65:35 the universe's expansion meaning that
65:38 individual atoms molecules and even
65:41 larger structures like rocks and human
65:43 bodies are not stretched by Cosmic
65:46 expansion the fact that Quantum
65:48 processes continue uninterrupted by
65:50 Cosmic expansion speaks to the scale of
65:53 the forces involved the strong nuclear
65:56 force for instance is 100 times stronger
65:58 than electromagnetism and millions of
66:00 times stronger than gravity it's this
66:03 strength that keeps protons and neutrons
66:05 tightly bound within an atom's nucleus
66:08 preventing the universe's expansion from
66:10 having any measurable impact this is why
66:14 despite the universe expanding our
66:16 day-to-day lives remain unaffected by it
66:19 the atoms that make up your body are not
66:21 expanding nor are the distances between
66:24 the molecules in the air around around
66:25 you the forces that bind matter on small
66:28 scales are simply too strong for the
66:30 universe's gentle stretching to pull
66:32 them apart but does the expansion of the
66:34 universe play any role at all in the
66:36 quantum
66:37 realm while the immediate answer seems
66:40 to be no there are some intriguing
66:42 connections between Cosmic expansion and
66:44 quantum theory that scientists continue
66:47 to
66:47 explore one such connection lies in the
66:50 concept of quantum
66:52 fluctuations quantum theory tells us
66:55 that even in seemingly empty space there
66:58 are brief moments where particles pop in
67:00 and out of
67:01 existence these fluctuations occur on
67:04 incredibly small scales far smaller than
67:07 even
67:08 atoms some cosmologists believe that the
67:11 early universe's expansion especially
67:13 during Cosmic inflation was driven by
67:16 these Quantum
67:17 fluctuations during Cosmic inflation the
67:20 universe expanded at an unimaginably
67:23 fast rate stretching from subatomic
67:25 scale scales to Cosmic scales in a blink
67:27 of an eye this inflationary period was
67:30 influenced by Quantum fluctuations which
67:33 were stretched along with space these
67:36 fluctuations became the seeds for the
67:37 galaxies and Cosmic structures we
67:40 observe today in this sense the
67:43 expansion of space has roots in the
67:45 quantum World though the connection
67:47 between the two remains an area of
67:49 active research and debate another
67:52 potential link between the universe's
67:54 expansion and quantum theory
67:56 involves the concept of dark energy if
67:58 dark energy is indeed tied to the
68:00 quantum realm then the expansion of the
68:03 universe and the behavior of space on
68:05 the smallest scales might be more
68:07 connected than we currently
68:10 understand the concept of a heat death
68:14 expansion's Final
68:17 Consequence many scientists have
68:19 explored what the universe's expansion
68:21 could mean for the far future one of the
68:24 most widely discussed ideas is is the
68:26 concept of the heat death of the
68:28 universe this Theory suggests that if
68:31 the universe keeps expanding in
68:33 definitely it will eventually reach a
68:35 state where all energy is evenly
68:38 distributed and no more work can be done
68:41 this ultimate state of equilibrium is
68:44 sometimes referred to as the heat death
68:47 to understand the idea of heat death we
68:49 need to think about the concept of
68:50 entropy in simple terms entropy is a
68:54 measure of disorder or Randomness in a
68:56 system in the universe entropy tends to
68:59 increase over time meaning systems
69:01 become more disordered when a system
69:04 reaches maximum entropy there is no
69:06 further available energy to create
69:08 change or sustain processes for instance
69:11 the heat generated by stars is a form of
69:13 usable energy but as the universe
69:16 expands that energy spreads out becoming
69:19 less concentrated and less able to power
69:22 things like stars or galaxies the idea
69:25 of heat death comes from this principle
69:27 of increasing entropy as the universe
69:30 expands galaxies drift farther apart and
69:33 stars gradually burn through their fuel
69:36 over billions and trillions of years
69:39 Stars will exhaust their nuclear Fuel
69:41 and either collapse into black holes
69:43 Fade Into cold white dwarves or explode
69:46 in supern
69:47 noi without new sources of energy these
69:50 Stellar remnants will cool and darken
69:53 leaving behind a universe with less and
69:56 less
69:57 activity in the distant future the Milky
70:00 Way and its neighboring galaxies in the
70:02 local group May merge but beyond that
70:06 other galaxies will recede from view as
70:09 the universe expands faster than the
70:11 speed of light in this scenario the
70:14 universe becomes increasingly empty with
70:17 isolated pockets of matter surrounded by
70:20 vast expanses of
70:21 nothingness eventually the only
70:24 remaining sources of energy will be the
70:26 faint radiation left over from The Big
70:28 Bang and the occasional outbursts from
70:31 decaying black holes in the final stages
70:34 of the universe according to the heat
70:36 death scenario black holes themselves
70:39 will evaporate due to a process known as
70:41 Hawking
70:42 radiation this process predicted by
70:45 physicist Steven Hawking suggests that
70:48 black holes slowly lose mass by emitting
70:51 tiny amounts of radiation over
70:53 incredibly long time scales
70:56 while black holes might seem Eternal
70:58 even the largest black holes will
71:00 eventually evaporate leaving behind only
71:02 low energy
71:04 particles once all the black holes have
71:06 evaporated and all matter has decayed
71:09 into its most basic components the
71:11 universe will be a cold dark and empty
71:14 place this state is sometimes referred
71:16 to as the big
71:18 freeze in this distant future there will
71:21 be no more stars no more galaxies and no
71:25 more black holes the only thing that
71:27 will remain is a thin soup of low energy
71:30 particles spread across an immense and
71:33 ever expanding
71:34 void the heat death of the universe
71:37 represents a point where the universe
71:39 has reached maximum entropy at this
71:42 stage all energy is evenly distributed
71:45 without energy differences processes
71:47 like Star formation chemical reactions
71:50 or even movement at the atomic level
71:53 would cease in this state St the
71:56 universe would be effectively dead in
71:58 the sense that nothing would be
72:00 happening it's worth noting that the
72:03 heat death of the universe is just one
72:05 possible outcome it is based on current
72:08 understanding of cosmic expansion dark
72:11 energy and the laws of
72:13 thermodynamics if the universe continues
72:16 expanding indefinitely as it seems to be
72:19 and if Dark Energy remains constant the
72:22 heat death scenario becomes a strong
72:24 possibility
72:25 however there are still many
72:27 uncertainties in cosmology and our
72:30 understanding of the universe's
72:31 long-term future may change with new
72:34 discoveries one of the key factors
72:36 driving the universe towards heat death
72:38 is the role of dark energy if Dark
72:41 Energy continues to dominate the
72:42 universe's Behavior it could prevent new
72:45 structures from forming sealing the fate
72:47 of the universe as a cold expanding
72:51 void while this scenario may seem Bleak
72:54 it's important to to remember that the
72:56 timeline for the heat death of the
72:57 universe is incredibly long we're
73:01 talking about time scales so vast
73:03 trillions upon trillions of years that
73:06 it's difficult to even
73:08 imagine for now the universe is still in
73:10 a relatively active phase with stars
73:13 forming galaxies colliding and life
73:15 existing In Pockets across the cosmos
73:18 the heat death scenario represents the
73:20 very distant future far beyond the
73:22 lifespan of our solar system earth or
73:25 even the Milky Way
73:27 galaxy the Big Rip a violent end to
73:30 Cosmic expansion the idea of the
73:32 universe expanding endlessly is already
73:34 strange enough but there's another even
73:36 more dramatic possibility the Big Rip
73:39 unlike the gradual Cooling and fading
73:41 associated with the heat death scenario
73:44 the Big Rip imagines a far more violent
73:46 and abrupt end to the cosmos in this
73:49 hypothesis the expansion of the universe
73:52 doesn't just continue at its current
73:54 rate it accelerates to the point where
73:56 the very fabric of SpaceTime tears apart
74:00 taking everything within
74:02 it the Big Rip scenario starts with the
74:05 observation that the universe is
74:07 expanding faster and faster this
74:09 acceleration is largely attributed to
74:12 dark energy while Dark Energy currently
74:15 has a relatively mild effect gradually
74:18 pulling galaxies apart over time the Big
74:21 Rip hypothesis suggests that dark energy
74:24 could be become more powerful in the
74:26 future if Dark Energy increases in
74:29 strength it could push the universe to
74:31 expand at an ever increasing rate
74:34 eventually becoming so intense that it
74:36 overcomes even the fundamental forces
74:38 holding matter together in the Big Rip
74:41 scenario the expansion of the universe
74:43 would first become noticeable at the
74:45 largest
74:46 scales Galaxy clusters which are bound
74:49 together by gravity would begin to drift
74:52 apart faster than the speed of light
74:54 cutting off off entire regions of the
74:56 Universe from one
74:57 another as the expansion speeds up
75:00 galaxies themselves would be pulled
75:03 apart the gravitational forces that hold
75:05 stars in their orbits around the centers
75:08 of galaxies would be overwhelmed by the
75:10 stretching of space and the Stars would
75:13 scatter into the ever expanding
75:16 void but the Big Rip doesn't stop there
75:20 as time goes on and the expansion rate
75:23 increases even smaller structures like
75:25 solar systems would no longer be immune
75:28 the force of expansion would eventually
75:30 become stronger than the gravity that
75:32 holds planets in orbit around their
75:35 stars stars and their planets would be
75:37 torn away from each other drifting off
75:40 into the growing emptiness of space this
75:43 acceleration continues until it reaches
75:45 truly terrifying
75:47 scales eventually Dark Energy would
75:50 overpower the forces holding atoms
75:52 together the electromagnetic force that
75:55 BS electrons to the nucleus of an atom
75:57 would be no match for the universe's
75:59 expansion in this extreme future atoms
76:03 themselves would be torn apart leaving
76:05 only subatomic particles scattered
76:08 throughout an Ever growing
76:10 void in the final moments of the Big Rip
76:13 even the most fundamental aspects of
76:15 space and time would unravel the laws of
76:18 physics which governed the behavior of
76:21 particles and energy would cease to
76:23 apply as the expansion become comes
76:25 infinitely fast the universe would tear
76:28 itself apart leaving behind nothing but
76:31 isolated particles in a space that
76:33 stretches infinitely fast in every
76:36 direction this dramatic end would occur
76:38 in a finite amount of time meaning it
76:41 could theoretically happen relatively
76:42 quickly on a cosmic time scale if the
76:46 conditions for the Big Rip were met one
76:48 of the key ideas behind the Big Rip
76:50 hypothesis is that dark energy might not
76:53 behave in the same way forever
76:55 right now Dark Energy appears to have a
76:57 relatively constant effect on the
76:59 expansion of the
77:01 universe some theories suggest that dark
77:03 energy could change over time growing
77:06 stronger and more dominant as the
77:08 universe evolves if Dark Energy follows
77:11 this path it could eventually reach a
77:13 point where it accelerates the
77:15 universe's expansion so drastically that
77:17 the Big Rip becomes inevitable the
77:20 nature of dark energy is still not fully
77:23 understood if dark energy remains
77:25 constant as many models suggest then the
77:28 Big Rip will not occur and the universe
77:30 will follow a more gradual path toward
77:32 heat death but if Dark Energy increases
77:36 in strength the Big Rip could become a
77:38 reality leading to the destruction of
77:41 everything in the universe in a
77:43 relatively short
77:45 time astronomers and physicists have
77:48 been studying the universe's expansion
77:50 and the role of dark energy to better
77:53 understand these possibilities
77:55 observations of distant galaxies and
77:58 Supernova have provided strong evidence
78:00 that the universe is expanding and that
78:03 this expansion is accelerating but
78:06 determining whether the Big Rip will
78:08 happen requires more precise
78:10 measurements of dark energy and how it
78:12 behaves over time while the heat death
78:15 scenario takes place over unimaginably
78:17 long time scales trillions of years or
78:20 more the Big Rip could occur much sooner
78:23 depending on the strength of dark energy
78:25 and how quickly it accelerates the
78:27 expansion the Big Rip might happen in as
78:30 little as 22 billion
78:31 years though this may seem like an
78:34 enormous amount of time it's relatively
78:36 short compared to the long-term future
78:39 of a universe heading toward heat
78:42 [Music]
78:43 death are we living in a simulation of
78:46 an expanding
78:48 Universe the simulation Theory gained
78:51 widespread attention in recent years
78:53 though its roots can be traced back to
78:55 earlier philosophical debates about
78:57 reality and perception today with the
79:00 rapid advancements in technology and
79:02 Computing the idea that we might be
79:04 living in a sophisticated simulation has
79:06 become a serious consideration for some
79:09 scientists and thinkers one of the most
79:11 well-known proponents of this idea is
79:14 philosopher Nick Bostrom who in 2001
79:17 proposed that it's possible even
79:19 probable that advanced civilizations in
79:21 the distant future could create
79:24 simulations of entire
79:26 universes in these simulations the
79:28 inhabitants us for example might be
79:31 completely unaware of the artificial
79:33 nature of their
79:35 reality from this perspective the
79:38 expansion of the universe could be one
79:39 of many programmed features in the
79:42 simulation much like how modern video
79:44 games or virtual reality experiences
79:47 render space and time for players a
79:49 simulated Universe could follow similar
79:51 rules the expansion we observe with
79:54 galaxies moving away from one another
79:57 and space itself stretching might simply
79:59 be a feature programmed into the
80:01 simulation to give it an authentic
80:05 feel one of the Intriguing aspects of
80:07 this theory is how the expansion of the
80:10 universe fits neatly within the
80:12 framework of a
80:13 simulation just as a video game World
80:16 grows or changes based on the player's
80:18 movement or actions our universe could
80:21 be expanding in a way that aligns with
80:23 the rules of the simulation this
80:26 expansion which is accelerating due to
80:29 Dark Energy could be a part of the
80:31 simulation's evolving
80:32 environment as we continue to explore
80:35 the universe and make new discoveries
80:37 it's possible that what we see is simply
80:40 the simulation rendering more space and
80:42 time for us to observe and
80:45 explore in this sense the simulation
80:48 hypothesis offers an explanation for why
80:50 the universe might be expanding instead
80:53 of being a natural process governed by
80:55 fundamental physics the expansion could
80:58 be a consequence of the computational
80:59 rules that govern the simulation it
81:02 might be the result of the simulation
81:04 creators deciding to continuously expand
81:06 the boundaries of what is observable
81:08 giving the appearance of an Ever growing
81:12 Universe the nature of the expansion
81:14 itself could also raise questions about
81:17 the limitations of the
81:19 simulation if the universe is indeed
81:21 expanding faster and faster it might
81:24 suggest that the simulation is
81:26 continually generating new space as it
81:29 needs to this would mirror how in
81:32 computer simulations the environment is
81:35 often generated dynamically as the user
81:37 explores new areas it's possible that if
81:41 we are living in a simulation the
81:43 universe is expanding not because of
81:45 natural laws but because the simulation
81:48 requires more space as we look further
81:50 and deeper into the
81:53 cosmos another interesting angle of the
81:55 simulation theory is the potential for
81:58 glitches or anomalies within the
82:00 expanding Universe in video games or
82:03 simulations glitches or errors can occur
82:06 when the system encounters something it
82:08 wasn't programmed to handle if we are
82:10 living in a simulation it's possible
82:13 that certain Cosmic phenomena could
82:15 represent glitches in the simulation's
82:17 code for instance the strange behavior
82:20 of dark energy which seems to be pushing
82:23 the universe apart as at an accelerating
82:25 rate might be an unintended consequence
82:28 of the simulation's
82:30 parameters this could explain why Dark
82:32 Energy behaves so mysteriously and why
82:35 we have struggled to fully understand it
82:38 the simulation hypothesis also provides
82:40 another perspective on the limits of the
82:43 observable
82:44 universe in a simulated reality there
82:47 could be a finite boundary to what we
82:49 are allowed to see or
82:51 experience this boundary could take the
82:53 form of the cosmology iCal Horizon the
82:56 limit Beyond which light hasn't had
82:58 enough time to reach us since the
82:59 universe began in a simulation this
83:03 could be an intentional boundary created
83:05 by the programmers ensuring that we can
83:07 never fully observe or interact with
83:09 certain parts of the
83:10 universe the expansion of the universe
83:13 pushing distant galaxies Beyond this
83:16 Horizon could be a way of maintaining
83:18 this boundary within the
83:20 simulation additionally if we are in a
83:23 simulation it's possible that time
83:26 itself could be part of the
83:28 programming the flow of time like the
83:30 expansion of space could be an artifact
83:33 of the simulated reality in this case
83:37 the passage of time and the expansion of
83:39 the universe might be intertwined both
83:42 controlled by the simulation rules this
83:45 might explain why the universe's
83:47 expansion appears to be
83:49 accelerating as the simulation
83:51 progresses the creators could be
83:53 adjusting the rate of expansion ion
83:55 either as a natural consequence of the
83:57 simulation's parameters or as part of a
83:59 deliberate decision of course there is
84:02 no concrete evidence that we are living
84:04 in a simulation and the expansion of the
84:07 universe is generally understood through
84:08 the lens of physics and
84:10 cosmology however the simulation
84:13 hypothesis provides an intriguing
84:15 alternative way of thinking about Cosmic
84:17 expansion and the universe as a whole
84:20 exotic matter and energy could they
84:23 control expansion
84:25 speculation about the nature of the
84:26 universe's expansion has also LED
84:28 scientists to consider the possibility
84:31 of exotic forms of matter and energy
84:33 playing a key role in controlling or
84:35 influencing this process while we are
84:38 familiar with the ordinary matter that
84:40 makes up stars planets and galaxies
84:43 exotic matter and energy hypothetical
84:45 forms that don't behave like anything we
84:47 know could hold answers to some of the
84:49 most profound Mysteries surrounding the
84:51 universe's
84:53 expansion one of of the biggest puzzles
84:55 in cosmology is the nature of dark
84:57 energy unlike normal matter and energy
85:01 Dark Energy doesn't appear to interact
85:03 with anything in the way we expect it's
85:05 essentially invisible and undetectable
85:08 except through its effects on the
85:09 universe's large scale structure as the
85:13 universe continues to expand at an ever
85:15 increasing rate Dark Energy seems to be
85:17 driving this process but there's no
85:20 clear understanding of what Dark Energy
85:22 actually is some have speculated that it
85:25 could be a form of exotic energy that
85:27 behaves differently from anything we've
85:29 ever
85:30 encountered exotic energy forms could in
85:33 theory alter the rate of cosmic
85:35 expansion if Dark Energy itself is some
85:38 kind of exotic Force then it might be
85:40 possible that variations in its
85:42 properties could lead to changes in how
85:44 fast the universe expands in certain
85:47 regions of space exotic energy might
85:49 become more or less concentrated causing
85:52 the rate of expansion to fluctuate
85:54 this could explain why we observe the
85:56 universe expanding faster over time as
85:59 if something in the fabric of space is
86:01 evolving in ways that we don't yet
86:05 understand another speculative idea
86:08 involves the existence of exotic forms
86:10 of matter unlike ordinary matter which
86:13 clumps together to form galaxies and
86:15 stars exotic matter might have unusual
86:18 properties that allow it to behave
86:20 differently in the context of cosmic
86:22 expansion
86:24 some theories suggest that exotic matter
86:26 could have negative Mass meaning that
86:29 instead of being attracted to other
86:31 matter it would repel it if such a form
86:34 of matter existed it could potentially
86:36 counteract the effects of gravity which
86:38 normally slows down expansion on smaller
86:41 scales in some models certain parts of
86:44 the universe might contain higher
86:45 concentrations of exotic matter or
86:47 energy While others have
86:50 less this could lead to a scenario where
86:53 different regions EXP expand at
86:54 different rates while the overall
86:57 Universe appears to be expanding at a
86:59 uniform rate on large scales it's
87:02 possible that localized regions could
87:04 experience accelerated or slowed
87:07 expansion depending on the distribution
87:09 of exotic matter or energy within them
87:13 there are also ideas about the potential
87:15 for exotic matter or energy to actively
87:17 influence the shape of
87:19 SpaceTime in general relativity the
87:22 distribution of mass and energy directly
87:24 affects the curvature of SpaceTime
87:27 ordinary matter curves space in a way
87:29 that leads to the formation of stars
87:31 planets and galaxies but exotic matter
87:35 with its unusual properties might curve
87:37 SpaceTime in completely different
87:40 ways some researchers have proposed that
87:43 the presence of exotic matter could
87:45 create regions of space that expand or
87:48 contract in unexpected ways possibly
87:51 even creating bubbles of SpaceTime that
87:54 behave differently from the surrounding
87:57 Universe these bubbles of SpaceTime
88:00 influenced by exotic matter or energy
88:02 might expand faster or collapse inward
88:05 this could lead to strange effects such
88:08 as the creation of many universes within
88:10 our own if these ideas are correct then
88:13 the universe's expansion could be far
88:15 more complex than a simple uniform
88:18 process instead it might involve pockets
88:21 of exotic matter and energy that shape
88:23 the cosmos in ways we can't yet observe
88:27 directly if such exotic energy exists it
88:30 could be harnessed in the future to
88:32 control or even reverse the expansion of
88:35 the
88:35 universe while this remains firmly in
88:38 the realm of speculation some scientists
88:40 have wondered whether it might be
88:42 possible to manipulate the expansion of
88:44 space if we could somehow interact with
88:46 dark energy or other exotic
88:49 forces this might allow for technologies
88:51 that could expand or contract regions of
88:54 space at will potentially opening up new
88:57 possibilities for future
88:59 Civilizations for instance if a way were
89:01 found to influence the rate of expansion
89:03 locally it could lead to new methods of
89:06 space travel or even allow for the
89:08 creation of isolated pockets of
89:10 SpaceTime with different physical
89:14 properties the universe's final State
89:17 expansion at the End of Time the final
89:20 state of the universe is an intriguing
89:22 question for which scientists have
89:24 proposed several theories all of them
89:27 hinge on the continued expansion of
89:29 space and what that means for matter
89:32 energy and the forces that govern the
89:36 cosmos whether the universe continues to
89:38 expand forever stops expanding or even
89:42 reverses its course the behavior of
89:44 expansion dictates the universe's
89:48 future apart from the big freeze and big
89:51 rip scenarios previously discussed there
89:54 there is a possibility known as the Big
89:56 Crunch this suggests that the expansion
89:58 of the universe could eventually reverse
90:01 if the density of matter and energy in
90:03 the universe is high enough gravity
90:06 could overcome the force of expansion
90:08 causing the universe to stop expanding
90:11 and begin Contracting over time galaxies
90:15 stars and planets would draw closer
90:17 together eventually collapsing into a
90:19 single
90:20 point this could lead to a scenario
90:22 similar to The Big Bang but in Reverse
90:25 where all matter is compressed into an
90:27 incredibly dense State while the Big
90:30 Crunch is not a currently favid Theory
90:33 as observations suggest the universe's
90:35 expansion is
90:36 accelerating however it remains a
90:38 possible outcome if the nature of dark
90:41 energy were to change in the future yet
90:43 another possibility is tied to quantum
90:45 mechanics and the concept of a vacuum
90:48 Decay according to this idea the
90:51 universe exists in a false vacuum state
90:54 a temporary unstable version of space
90:56 that could transition to a more stable
90:59 State this transition Could Happen
91:01 spontaneously at any point triggered by
91:04 a Quantum
91:05 fluctuation If This Were to occur it
91:08 would create a bubble of true vacuum
91:10 that expands at the speed of light
91:12 destroying everything in its
91:15 path the universe as we know it would
91:18 cease to exist as it's replaced by this
91:20 new vacuum state in this scenario the
91:24 end of the universe could come without
91:27 warning there are also more speculative
91:30 theories involving the
91:32 Multiverse for example some theories
91:34 suggest that black holes could act as
91:37 gateways to other universes and as our
91:40 universe winds down new ones could
91:42 emerge this would mean that while our
91:45 universe may have a finite end the
91:47 Multiverse itself continues on in a
91:50 NeverEnding cycle of creation and
91:52 destruction
91:54 could life survive in a cold expanded
91:57 universe the most likely eventual fate
91:59 of the universe seems to involve a cold
92:01 stretched State often referred to as the
92:03 heat death or big freeze in this
92:06 scenario Stars Burn Out galaxies drift
92:09 apart and the universe becomes dark and
92:12 cold a natural question that arises is
92:15 whether life could somehow survive in
92:17 such a
92:18 universe while this may seem unlikely at
92:20 first the resilience and adaptability of
92:23 Life As We know it suggests that it's
92:25 worth exploring how life might adapt to
92:28 these extreme
92:29 conditions in today's universe life
92:32 depends on stars for energy sunlight
92:35 Powers ecosystems and the heat from
92:37 stars is crucial for maintaining
92:39 habitable conditions on planets like
92:41 Earth but in a universe where stars have
92:44 burned out and the temperature has
92:46 dropped close to absolute zero
92:48 alternative sources of energy would be
92:50 necessary for life to continue one
92:53 possibility ility is that advanced
92:55 civilizations if they exist could
92:57 harness energy from processes that don't
93:00 rely on stars for instance black holes
93:04 which persist even after Stars die might
93:06 be used as sources of energy some
93:09 theories suggest that matter falling
93:11 into a black hole could release
93:13 tremendous amounts of energy and perhaps
93:15 civilizations could tap into this energy
93:18 to survive in The Long Dark
93:21 Universe another idea is that life might
93:23 evolve to survive in environments with
93:25 very little
93:26 energy on Earth we already see examples
93:30 of extremophiles organisms that thrive
93:32 in extreme conditions such as deep sea
93:35 hydrothermal vents freezing Arctic
93:37 Waters or highly radioactive
93:40 environments these creatures demonstrate
93:43 that life can adapt to environments that
93:45 seem inhospitable to most forms of life
93:48 if life could exist in such extreme
93:51 conditions on Earth it's possible that
93:53 given enough time life could evolve to
93:56 survive in the cold expanded universe
93:59 life forms in this distant future might
94:01 be unlike anything we can currently
94:03 imagine relying on biochemical processes
94:06 that operate at much lower energy levels
94:09 than those we see today additionally
94:12 life might use technology to extend its
94:14 existence if civilizations become
94:17 Advanced enough they could potentially
94:19 create artificial habitats or
94:21 environments where conditions are
94:22 controlled this could involve building
94:25 large structures to trap and store heat
94:27 or energy from the universe's last
94:29 remaining sources these civilizations
94:32 might also find ways to slow down their
94:34 metabolic processes reducing the amount
94:36 of energy needed to survive time could
94:39 become a key resource with civilizations
94:42 finding ways to extend their existence
94:44 for as long as possible by stretching
94:46 out the limited energy available to them
94:49 there's also the possibility that
94:51 intelligent life could find ways to
94:53 manipulate at the fabric of the universe
94:55 itself this might involve tapping into
94:58 exotic physics such as utilizing dark
95:00 energy or manipulating Quantum fields to
95:03 create new sources of energy these
95:05 speculative ideas reflect the vast
95:08 potential for Innovation and adaptation
95:11 that could come from Advanced
95:12 civilizations faced with the challenge
95:15 of surviving in a dying
95:17 Universe yet even with such advancements
95:20 there are limits to how long life could
95:22 continue in an ever expanding cooling
95:26 universe as the universe stretches
95:28 further the distance between galaxies
95:31 grows larger isolating any remaining
95:34 civilizations communication and travel
95:37 between galaxies would become
95:38 increasingly difficult eventually
95:40 becoming impossible as galaxies recede
95:43 Beyond each other's reach traveling
95:45 faster than the speed of light due to
95:47 Cosmic
95:48 expansion over time civilizations would
95:52 become isolated in their own local
95:54 regions of space cut off from any others
95:57 that might
95:58 exist in a universe approaching heat
96:01 death all processes slow down as the
96:03 temperature approaches absolute zero
96:06 this would affect the fundamental laws
96:08 of physics slowing down chemical
96:10 reactions and biological processes
96:13 eventually life no matter how advanced
96:16 would struggle to find the energy needed
96:18 to survive even the most efficient forms
96:21 of life would likely face a limit where
96:23 the energy required to maintain basic
96:25 functions like reproduction or thinking
96:29 becomes too sparse to
96:31 sustain some radical theories suggest
96:33 that life could potentially exist in
96:35 forms that don't require energy in the
96:37 way we understand it in the distant
96:39 future life might not be based on carbon
96:42 or other familiar elements perhaps life
96:45 could evolve to exist in a form that is
96:47 purely informational where Consciousness
96:49 is preserved in a digital or Quantum
96:52 state in such scenario life might
96:55 continue even after the physical
96:56 Universe has become too cold to support
96:59 biological life these life forms might
97:02 not need physical matter to exist and
97:04 they could theoretically persist
97:06 indefinitely long after the universe's
97:08 energy has been depleted other
97:11 speculations involve the possibility of
97:13 Life escaping to other universes if
97:16 Multiverse theories are correct there
97:18 may be other universes with different
97:20 physical laws or different conditions
97:22 where life could Thrive Advanced
97:25 civilizations might one day discover
97:27 ways to move between universes leaving
97:29 this one behind as it approaches its
97:31 cold expanded end this would offer an
97:34 Escape Route for life allowing it to
97:36 continue in more favorable conditions
97:39 even as our universe winds down
97:42 expansion and the future of cosmic
97:45 communication if life remains during the
97:47 final stages of the universe's continual
97:50 expansion one of its most significant
97:52 effects will be on the ability of
97:54 Galactic Civilizations to
97:56 communicate while galaxies today are
97:59 relatively close in the grand scheme of
98:01 the universe Cosmic expansion will push
98:04 them so far apart that communication
98:06 between them will be nearly impossible
98:08 if not entirely cut off in Practical
98:12 terms this means that any form of
98:14 communication whether via
98:16 electromagnetic waves radio signals or
98:19 even hypothetical advanced communication
98:22 Technologies will become increasingly
98:25 difficult and ultimately
98:27 impossible galaxies that were once
98:30 visible will fade beyond the observable
98:32 Horizon becoming unreachable both
98:35 visually and in terms of
98:38 communication for civilizations existing
98:41 in different galaxies this isolation
98:43 could have profound
98:45 consequences if intelligent life exists
98:47 elsewhere in the universe as some
98:49 theories suggest it's possible that in
98:52 the early days of cosmic Evolution
98:54 communication between distant
98:56 civilizations could have been feasible
98:58 though there is no evidence this has
99:00 happened however as time progresses and
99:03 Cosmic expansion accelerates even the
99:06 possibility of future communication
99:08 across galaxies will vanish the universe
99:12 will enter an era of isolation where
99:15 each Galaxy or more accurately each
99:17 group of gravitationally bound galaxies
99:20 will become its own Cosmic Island
99:23 separated from others by unbridgeable
99:27 distances the implications of this
99:29 isolation stretch Beyond just the
99:32 inability to communicate as galaxies
99:34 move beyond the observable Horizon they
99:37 will effectively disappear from view all
99:39 together civilizations in the far future
99:43 will only be able to observe the
99:44 galaxies within their own local group
99:47 while the rest of the universe Fades
99:49 Into Darkness this isolation could also
99:52 impact the exchange of knowledge and
99:54 resources assuming Advanced
99:56 civilizations had developed methods of
99:58 Intergalactic trade or shared scientific
100:01 discoveries such activities would become
100:04 increasingly unfeasible and
100:06 civilizations would have to rely
100:08 entirely on their own Galaxy's resources
100:10 and knowledge base the idea of a
100:13 cosmically connected Universe even if
100:15 only hypothetical at present would
100:17 become a distant memory Cosmic expansion
100:21 would thus draw a boundary between
100:22 galaxies that no form of technology or
100:25 knowledge could overcome even the most
100:28 advanced forms of communication far
100:30 beyond what Humanity can currently
100:32 imagine would be subject to the
100:34 limitations imposed by the speed of
100:36 light and the Relentless stretching of
100:38 space no signal no matter how powerful
100:42 could ever travel fast enough to keep up
100:44 with the rate of expansion between
100:46 galaxies that are Beyond a certain
100:48 distance from one another for
100:50 civilizations that exist within their
100:52 own Galaxy
100:53 communication and exploration would
100:55 still be possible at least on local
100:58 scales Cosmic expansion only becomes an
101:01 issue when attempting to bridge the
101:03 enormous distances between galaxies that
101:06 are not gravitationally bound to each
101:08 other within individual galaxies or
101:11 clusters of galaxies gravitational
101:13 forces are strong enough to resist the
101:15 effects of expansion allowing for
101:18 communication and interaction to
101:20 continue if there were still
101:22 civilizations in this far future would
101:24 they have developed methods to
101:26 anticipate or cope with this isolation
101:29 would they find Ways to Leave a record
101:30 of their existence before the expansion
101:33 renders them
101:35 unreachable or might civilizations Focus
101:39 inward turning to their own Galactic
101:41 neighborhood for survival and growth in
101:44 the face of inevitable
101:47 isolation black holes in an expanding
101:51 Universe in an expanding Universe the
101:54 role and fate of black holes becomes
101:57 fascinating to explore especially when
102:00 considering their potential influence on
102:02 the long-term fate of cosmic expansion
102:04 and their significance for any advanced
102:06 civilizations that may exist in the
102:08 distant future one key aspect of black
102:11 holes in an expanding universe is how
102:14 they themselves evolve over time black
102:17 holes are known to grow in size by
102:19 absorbing matter and merging with other
102:21 black holes but as the universe expands
102:23 and galaxies drift apart the amount of
102:26 available matter for black holes to
102:28 consume gradually diminishes in an
102:30 increasingly empty Universe the large
102:33 scale structures like galaxies and
102:35 Galaxy clusters that feed black holes
102:37 will become
102:39 isolated as a result black holes will
102:42 have less material to draw in slowing
102:44 down their growth over time as the
102:47 universe stretches and cools the density
102:50 of matter decreases and black holes May
102:53 cease to grow entirely instead existing
102:56 as the last remnants of a universe that
102:58 was once filled with stars and
103:01 galaxies despite this decline in
103:03 available matter black holes have a
103:06 particularly enduring presence in the
103:08 cosmos while Stars will burn out and
103:11 galaxies will fade away black holes can
103:13 last for incredibly long periods of time
103:17 in fact the most massive black holes
103:19 could potentially Outlast almost
103:21 everything else in the universe
103:23 super massive black holes which exist at
103:26 the centers of galaxies will persist
103:28 long after stars have exhausted their
103:30 fuel and galaxies have stopped
103:33 forming over vast periods of time black
103:36 holes slowly emit Hawking radiation
103:39 causing them to lose mass and eventually
103:42 evaporate however the process of Hawking
103:45 radiation is incredibly slow especially
103:48 for large black holes in a universe that
103:51 is expanding and Cooling the evaporation
103:53 of black holes could take trillions of
103:55 years the idea that black holes will one
103:58 day Disappear Completely aligns with
104:00 scenarios like the heat death of the
104:02 universe where entropy increases until
104:06 no usable energy
104:08 remains yet before this distant future
104:11 is reached black holes might play a
104:13 crucial role for the final civilizations
104:16 that find themselves in an increasingly
104:18 inhospitable universe as the universe
104:21 expands and energy sources become more
104:24 scarce Advanced civilizations could look
104:26 to black holes as a last vital source of
104:30 energy one proposed method for
104:32 harnessing energy from black holes is
104:34 known as the Penrose process in this
104:37 process objects can be sent into the
104:39 region around a rotating black hole
104:41 where they can extract energy from its
104:44 rotation this method could provide a
104:46 means for civilizations to continue to
104:49 generate power even as stars grow dim
104:52 and other s sources of energy become
104:55 inaccessible another way is through the
104:57 use of the accretion discs that form
104:59 around black holes these discs consist
105:03 of gas and dust that spiral into the
105:05 black hole releasing vast amounts of
105:08 energy in the
105:09 process even in an expanding Universe
105:13 some black holes will still have
105:14 accretion discs for a long time as they
105:17 continue to draw in material from their
105:19 surroundings for advanced civilizations
105:22 cap uring the energy released from these
105:24 discs could be a Lifeline in an
105:26 otherwise darkening
105:28 Cosmos black holes may also offer a way
105:31 for civilizations to preserve knowledge
105:33 or even survive for longer periods of
105:35 time some have suggested that
105:37 civilizations could create structures
105:39 near black holes where the intense
105:41 gravitational fields cause time to slow
105:43 down relative to the rest of the
105:46 universe this time dilation could
105:48 potentially allow civilizations to
105:50 experience time at a slower rate if
105:53 effectively prolonging their existence
105:54 as the universe continues its Relentless
105:57 expansion in such a scenario life could
106:01 persist for much longer than it would in
106:02 regions of space unaffected by strong
106:05 gravitational
106:06 forces black holes could represent some
106:09 of the last bastions of complexity in an
106:11 Ever simplifying universe as the
106:14 universe expands matter becomes more
106:17 diffuse and the structures that once
106:19 Define the cosmos Galaxy stars and
106:21 planets gradually Fade Away black holes
106:25 with their intense gravitational fields
106:27 and unique properties offer one of the
106:30 few remaining sources of order and
106:32 energy in a universe heading toward
106:34 increased entropy whether they serve as
106:37 energy sources for the last
106:39 civilizations or simply as Cosmic relics
106:42 their presence will shape the final
106:44 chapter of the universe's
106:47 story observing the expanding Universe
106:50 future telescopes and tools
106:54 to answer these profound questions that
106:56 we ask ourselves it is important that
106:58 Humanity develop far more advanced tools
107:01 and Technologies than we currently have
107:03 to observe the universe and illuminate
107:05 our ignorance the current generation of
107:08 telescopes has given us remarkable
107:10 insights into the nature of cosmic
107:12 expansion but future instruments promise
107:14 to take these discoveries even further
107:17 scientists and Engineers are working on
107:19 cuttingedge telescopes and space
107:21 observatories that will allow us to
107:23 probe deeper into the universe revealing
107:26 new details about its expansion its past
107:29 and its
107:30 future one of these tools is the James
107:33 web Space Telescope aka the jwst which
107:36 was designed to succeed the Hubble Space
107:39 Telescope while Hubble provided
107:41 incredible images and data especially on
107:43 the red shift of galaxies and the early
107:45 Universe the jwst is built to observe
107:49 infrared light which allows it to look
107:51 even farther back in time
107:53 as the universe expands light from
107:55 distant galaxies becomes stretched into
107:57 longer infrared
107:59 wavelengths jwsd is optimized to capture
108:02 this light giving us a better
108:05 understanding of galaxies that formed
108:06 just a few hundred million years after
108:08 the big bang observing these early
108:11 galaxies helps scientists learn How the
108:14 Universe expanded in its early stages
108:16 and how that expansion has evolved over
108:19 time the European Space Agency or SAA is
108:23 also contributing to the exploration of
108:25 cosmic expansion through missions like
108:28 the uclid Space Telescope ylid is
108:31 designed specifically to study dark
108:33 energy and dark matter two of the most
108:36 mysterious components of the
108:38 universe dark energy which is driving
108:41 the accelerated expansion of the
108:42 universe remains poorly understood ucl's
108:46 goal is to map the geometry of the
108:48 universe by measuring the distribution
108:50 of galaxies and Galaxy clusters over
108:52 over time by creating this Large Scale
108:55 map scientists hope to pinpoint the
108:58 effects of dark energy and how it is
109:00 shaping the universe's
109:02 expansion uclid will offer new clues
109:04 about the nature of this force and how
109:06 it has influenced the universe's rate of
109:09 expansion another key future project is
109:11 the square kilometer array an
109:13 international effort to build the
109:15 world's largest radio telescope unlike
109:18 traditional optical telescopes the ska
109:21 will use radio waves to observe observe
109:23 the universe allowing it to detect
109:25 signals from some of the most distant
109:27 objects ever observed radio waves are
109:30 less affected by Cosmic dust enabling
109:33 the SK to peer through obstacles that
109:35 block other types of light with its vast
109:38 network of antennas spread across
109:40 continents the ska will be able to
109:42 collect incredibly detailed data on
109:44 distant galaxies cosmic background
109:47 radiation and the large scale structure
109:49 of the universe this will help
109:51 scientists better understand how Cosmic
109:54 expansion has affected the distribution
109:56 of matter and energy throughout the
109:58 Universe the study of cosmic expansion
110:01 isn't just limited to observing galaxies
110:04 the next generation of gravitational
110:06 wave detectors also promises to shed new
110:08 light on the expanding
110:10 Universe gravitational waves are ripples
110:13 in SpaceTime caused by violent events
110:16 like the Collision of black holes these
110:18 waves travel across the universe and
110:20 carry information about the structure of
110:22 SpaceTime
110:23 itself future detectors such as the
110:26 planned laser interferometer space
110:28 antenna or Lisa will be able to detect
110:31 gravitational waves with greater
110:33 sensitivity than current instruments by
110:36 analyzing these waves scientists can
110:38 learn more about the expansion of space
110:40 on both large and small
110:43 scales gravitational waves provide a
110:45 unique way to probe the universe because
110:48 they are not affected by light or matter
110:51 making them a powerful tool for studying
110:53 the universe's
110:55 Evolution advancements in data analysis
110:58 and computer simulations are also
111:00 helping scientists make sense of the
111:02 enormous amounts of information they
111:04 collect machine learning and AI are
111:07 playing an increasingly important role
111:09 in
111:10 astronomy with the vast data produced by
111:12 modern telescopes AI algorithms are
111:15 being developed to sift through this
111:17 information identify patterns and make
111:20 predictions about the behavior of cosmic
111:23 structures these tools are particularly
111:25 useful in studying Cosmic expansion
111:28 because they can track how galaxies move
111:30 and evolve over billions of years
111:32 allowing scientists to test different
111:34 models of expansion and Dark Energy
111:37 Future missions to study the CMB will
111:40 also be crucial in understanding the
111:41 early stages of the universe's
111:44 expansion telescopes like the plank
111:46 satellite have already provided detailed
111:48 maps of the CMB revealing the tiny
111:51 fluctuations that EV led to the
111:53 formation of galaxies and Galaxy
111:55 clusters however upcoming missions are
111:58 expected to refine these measurements
112:00 even further helping to clarify how
112:03 Cosmic inflation the rapid expansion
112:05 that occurred right after the big bang
112:07 set the stage for the universe's
112:09 continued
112:11 expansion ground-based telescopes such
112:13 as the vir ruin Observatory will focus
112:16 on creating deep wide field surveys of
112:19 the Sky by continuously scanning large
112:22 port pors of the universe The reubin
112:24 Observatory will be able to track the
112:26 motion of millions of galaxies providing
112:29 detailed data on the large- scale
112:31 structure of the
112:32 universe this Observatory will
112:34 contribute to our understanding of dark
112:36 energy by observing how galaxies and
112:38 supern noi move and change over time the
112:42 telescope's ability to monitor the sky
112:44 regularly will also allow scientists to
112:47 detect unexpected phenomena giving them
112:49 the chance to study events related to
112:51 Cosmic expansion in real
112:54 time the limits of human understanding
112:57 can we ever fully grasp
112:59 expansion Cosmic expansion touches on
113:02 some of the most profound and complex
113:04 questions about the nature of reality
113:06 time and space itself while science has
113:09 made incredible strides in explaining
113:11 How the Universe expands and how we can
113:14 observe it the deeper nature of
113:16 expansion why it happens what might lie
113:19 Beyond it and whether it will ever stop
113:22 May remain shrouded in
113:24 mystery in a way the more we learn about
113:27 Cosmic expansion the more questions we
113:30 encounter for example we understand that
113:32 distant galaxies are moving away from us
113:35 and that this movement accelerates due
113:37 to Dark Energy but Dark Energy itself is
113:40 one of the greatest mysteries in modern
113:42 science we know it exists because we
113:45 observe its effects but we have no clear
113:47 idea of what it actually is is it a
113:50 force a field a property of space itself
113:54 and why did it begin to dominate the
113:56 universe's expansion at a specific point
113:59 in time these questions challenge our
114:02 understanding of the Universe on a
114:04 fundamental level The cosmological
114:07 Horizon constrains us placing the rest
114:10 of the universe effectively beyond our
114:12 reach forever it's as if we are trapped
114:15 inside a bubble of knowledge unable to
114:17 directly observe what lies
114:19 beyond the question becomes can we ever
114:22 know what the universe is like in these
114:24 unreachable regions or are they destined
114:27 to remain forever hidden even within our
114:30 observable universe the complexities of
114:33 cosmic expansion may be too vast for
114:35 human
114:37 understanding theoretical physicists use
114:39 incredibly complex equations to describe
114:42 how space expands how galaxies form and
114:44 move and how dark energy influences
114:47 these processes but there is a
114:49 difference between describing something
114:51 mathematically and
114:52 understanding it we can predict with
114:55 great accuracy how galaxies will behave
114:57 over time but we are still far from
114:59 grasping the deeper why Behind These
115:02 behaviors in this sense Cosmic expansion
115:06 may be a phenomenon we can describe but
115:08 never fully explain human perception and
115:11 reasoning are shaped by our experiences
115:13 on Earth where time moves forward in a
115:16 linear fashion space is relatively
115:18 stable and the forces of nature behave
115:21 in predictable ways
115:23 Cosmic expansion challenges all of these
115:26 assumptions time itself May behave
115:28 differently on the grandest scales and
115:30 the concept of Infinite Space defies
115:33 human
115:34 intuition our brains are not wired to
115:36 think about infinity or to easily grasp
115:38 four-dimensional SpaceTime much less the
115:41 possibility that space could be infinite
115:43 and yet still
115:45 expanding these abstract ideas push the
115:48 boundaries of what the human mind can
115:50 process some have argued that there will
115:53 always be aspects of the universe that
115:56 remain beyond our understanding not
115:58 because we lack the right tools or
116:00 equations but because the universe might
116:03 not be fully knowable they suggest that
116:05 there might be limits to human cognition
116:08 that no amount of technological
116:09 advancement or mathematical Insight can
116:12 overcome we may be able to observe the
116:15 effects of cosmic expansion but the true
116:17 nature of the universe might be so
116:19 complex that it surpasses our ability to
116:22 fully grasp it at the same time there is
116:26 always a drive in science to push beyond
116:28 the limits the expansion of the universe
116:30 was once an unimaginable idea and now it
116:33 is a fundamental part of our
116:35 understanding of the cosmos whether
116:37 these Mysteries are forever beyond our
116:39 reach or simply waiting for the next
116:41 breakthrough is an open question what do
116:44 you think comment down below and if you
116:47 enjoyed this video consider leaving a
116:49 like and subscribing to the channel
116:51 thanks for watching in