Articles, Blog

Is The Universe Finite?

December 6, 2019

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PBS Digital Studios. Space is big. You just won’t believe how vastly, hugely,
mind-bogglingly big it is. Although according to a new paper, it may
literally be infinitely smaller than we previously thought. Every time you walk out the door, light from
the Big Bang strikes your face, enters your eyes. This is the cosmic microwave background radiation
– the left-over heat-glow from the very early universe. We can’t see this microwave light with our
eyes, but we can catch it with even a simple radio antenna. As soon as we became aware of its existence
we’ve been feverishly building better and better devices to collect it. Why? Because it encodes so many secrets. And within this light, a group of scientists
have just found evidence of the limits of space. A clue that our universe may be actually be
finite in size. Today on Space Time Journal Club we’ll delve
into the Nature Astronomy paper that just reported this: Planck evidence for a closed
Universe and a possible crisis for cosmology by Eleonora Di Valentino, Alessandro Melchiorri,
and Joe Silk. This is the map of the cosmic microwave background
– the CMB – made by the Planck satellite. We explored in a previous episode how that
speckled pattern is the frozen imprint of sound waves that reverberated through the
first few hundred thousand years after the big bang, only to be frozen in place as the
universe cooled. Analysis of the sizes of these speckles from
previous satellites, and the initial analysis from the Planck map, pointed to a universe that
is infinitely large and geometrically flat, and is dominated by the influences of dark
matter and a constant density of dark energy. For the most part this has agreed with our
observations of the modern universe. But more detailed study of the Planck data
has started to reveal tensions. We’ve talked about this so-called crisis
in cosmology – the Planck team calculate an expansion rate for the universe that does
not match the expansion rate observed today – particularly the modern expansion rate determined
from supernova measurements. And that’s even accounting for accelerating effect of
a constant dark energy. Despite this tension, the teams agree
on lots of things, including fact that the universe is, as close as we can tell, geometrically flat and infinite. But, I’ll come back to what exactly what I mean by that. But even this agreement seems to be fading. In the new study, astrophysicists claim to
have found clear evidence in the Planck data that the universe is NOT flat, but rather
curved inward on itself. If they’re right, the universe is not infinite
in extent. Before we get to the new study, let’s do
a super-quick review of geometry. Albert Einstein’s general theory of relativity
allows for three simple geometries for our universe. We have 1) a universe with positive curvature. The 2-D analogy for this is the surface of
a sphere, so a our 3-D space would be like the surface of a 4-dimensional sphere – also
known as a hypersphere. Just like with the 2-D spherical analog, lines
that start parallel in such a universe eventually come together. Such a universe has a finite volume, just
as a sphere has a finite surface area. If you travel far enough around you’ll get
back to where you started. Then there’s 2) the negatively curved universe,
analogous to a hyperbolic plane – an infinite saddle shape. All paths through space diverge from each
other. Such a universe is open – space goes on forever. And finally 3) the universe with zero curvature
– a geometrically flat universe. Parallel lines stay parallel, your high school
geometry still works, and again, space in such a universe goes on forever. The geometry of the universe is determined
by two things: 1) the mass and energy it contains. More stuff in the universe – a higher energy
density – means more gravity, which tends to pull a universe in on itself – it gives
positive curvature and closes the universe – making it finite. And 2) the rate of expansion. Rapid expansion tends to give negative curvature
and open the universe – make it infinite. The combination of these factors determine
the geometry. Like I said, previous studies were pointing
to a flat universe. For example, by looking at the geometry of
gigantic triangles defined by the largest of the speckles in the CMB. The curvature measured was consistent with
being zero – flat – but there’s always a degree of uncertainty due to the imperfect
nature of any measurement. The curvature COULD have been very slightly
positive or very slightly negative – just as the surface of the Earth appears flat if
you’re standing on the ground. It’s only when you get some elevation that
you see the curvature. But it turns out that evidence of very slight
curvature may have been hiding in the Planck data all along. The new study went much deeper into the Planck
data than just looking at triangles defined by the biggest blobs. The team analyzed ALL of the blobs. More accurately, they analyzed what we call
the power spectrum. That’s just the graph showing the distribution
of the different sizes of blobs in the CMB. Blob size is on the x-axis and number of blobs
of that size on the y. So we can see that we get a lot more blobs
at some sizes compared to others – with most blobs at around 1 degree on the sky. We talked about the power spectrum in enormous
detail in that earlier episode. One thing that we didn’t talk about is how
gravitational lensing influences the overall shape of the power spectrum. See, the light from the CMB doesn’t travel
straight to us. It passes through a universe full of galaxies
and galaxy clusters – all of which have enormous gravitational fields that act as lenses, slightly
deflecting the path of those rays of CMB light. The result is like looking at the universe
through a lumpy pane of glass. Everything is very slightly distorted. In the case of the CMB, this results in a
sort of smoothing or blurring out of the power spectrum- the peaks are less sharp than they
would be otherwise. Our brave scientists were able to determine
the amount of lensing present in the Planck CMB map – and they found way more than would
be expected for an open universe. See, gravitational lensing is caused by mass
– both dark matter and atoms. More lensing suggests the universe has a higher
energy density than previously thought. Remember that more energy density tends to
introduce positive curvature. The new study claims there’s enough extra
matter revealed by that lensing to actually close the universe into a finite hypersphere
surface rather than an infinite flat hyperplane. Obviously I’m glossing over a lot of details
here. These scientists didn’t just measure the
amount of lensing on its own. They created a model that included all of
the relevant parameters – the expansion rate, details of inflation, the amount and behavior
of all different types of mass and energy, etc. They found the range of models that fit the
shape of the power spectrum, and for the most part those pointed to positive curvature. That curvature was slight – meaning the universe
is still unthinkably vast, but if this is right then it’s not infinitely large. The researchers claim a greater than 99% statistical
confidence for positive curvature in this analysis. So, is the universe really closed and finite? Does that mean there’s enough matter to
cause it to re-collapse again? And can we find a faster route to India by
traveling all the way around the cosmos to get back to where we started? Well even if the universe is finite, it’s
still expanding and that expansion is accelerating. It will NEVER recollapse unless its physics
is very different to what we think. Also, beyond a certain distance from us that
expansion exceeds the speed of light, so there’s no lapping the universe regardless of its
geometry. There’s also a reason to be cautious before
we conclude that the universe is closed at all The researchers looked at a different indicator
of the amount of gravitational lensing: the so-called four-point correlation function. In short – lensing by a cluster of galaxies
tends to draw rays of light from different blobs together. A random distribution of blobs ends up with slight
clusterings. The four-point correlation function found
an amount of lensing consistent with the old result of less energy density and a flat universe. So why is there a conflict given that 99+%
confidence? It’s important to know that this percentage
is NOT the likelihood of the conclusion being correct. It’s the statistical confidence in the model
fit given the assumptions that went into the model. In other words, IF all of those assumptions
are correct then there’s less than 1% chance that a flat universe would look like
a positively curved universe just due to random uncertainties. So, there are three possibilities really:
one is that the universe really is positively curved and finite. Two is that the assumptions that went into
the model are wrong. We’ll come back to these. Three is that there’s a mistake – an issue
with the data. Let’s talk about that. Some very subtle systematic issue in the calibration
of the Planck data may have led to the unexpected results for both the geometry and the expansion
history of the universe. For example, the Planck CMB map required extremely
careful subtraction of all other sources of microwave radiation. If this step, or something like it, wasn’t
done perfectly it could lead to bad results. The “official” analysis of the Planck data
was extremely careful so any mistake would have to be very subtle. The authors of the new study redid part of
the Planck analysis to claim this evidence of positive curvature – which the Planck team
had themselves decided wasn’t significant. So did the new guys do a better job and prove
everyone else wrong? That would be surprising because most data
points to a flat universe. If this lensing signal is real then maybe
there’s curvature, or maybe its an indication of some unknown physics. In the case of the discrepancy in the expansion
rate, hidden physics is the great hope of many physicists. That “missing physics” could turn out to
be the subtle clue needed to push our understanding of the universe to the next level. For example, if the expansion rate of the
universe really has evolved it may mean that the behavior of dark energy is changing – and
that could reveal the true nature of dark energy. In fact, if the universe really is curved
and closed, the discrepancy between the early universe and modern expansion rates becomes
even stronger. That’s because the previous calculations
of that discrepancy assumed a flat universe. So, physicists get even more excited if this
result holds up. OK, lots of ifs and buts – and that is okay,
because that’s how science works. We are very careful about how we talk about
confidence and proof. The new result opens a tantalizing new possibility,
and also hones in on the real physics of our universe – even if that means honing in on
any errors we’ve made in our analysis. The tension between the Planck results and
other cosmological measurements seems to be growing. The good news is that future missions will
surely resolve it. Perhaps identifying any errors, perhaps discovering
the nature of dark energy, and perhaps verifying the positively curved, finite geometry of
space time. If you want to dive deeply into understanding
the building blocks of space time then you need to study quantum theory. has a fun course called quantum
objects that include interactive challenges and problems to solve. Honestly, the best way to wrap your head around
quantum theory is to play with it. In this course you can explore the experiments
of quantum mechanics and use them to construct equations of motion, laws of physics, and
systems of measurement based on the algebra of quantum theory. Effective learning is about problem solving. To learn more about Brilliant, go to OK, so in the last episode we explored the
scientific and philosophical implications of the anthropic principle. But before we get to that, I want to invite
you to check out the Space Time discord, which you can access with the lowest $2 patreon
tier. There are loads of people over there talking
about all sorts of fascinating smart-person stuff 24-7, as well as making suggestions
for the show – some of which we’re definitely going to do. Here’s a discord question from Damagast: do
all PhD physicists casually talk about complex stuff like on Space Time videos, or do most
employed physicists just shut up and calculate? Well, actually, both. I know plenty of physicsts who LOVE talking
about the most complex, speculative, and philosophical stuff over a beer, and some who are laser
focused on their own field and don’t really think far beyond it. That’s ok too, but I prefer beers with the
former. So let’s see what you had to say about the the last episode. Scott Barnkow asks what are some testable
predictions of the refined anthropic principle? Well, I’m glad you asked Scott because next week we’re going to tell you about a very clear one: Stephen Weinberg’s prediction of the cosmological
constant years before dark energy was ever discovered. Speaking of next week, Vladimir postulates
that if there are to be trillions or quadrillions of humans in future space-faring civilizations,
isn’t it weird that we happen to be in the first 100 billion? Well, nice way to invent the doomsday argument Vladimir… like 35 years after Brandon Carter first proposed it. And we’ll be digging into that next week also. And we’ll answer your question P.S.Y – what
exactly DOES Nick Bostrum mean by “reference class” – as in, how do you choose the sample
of observers from which you consider yourself randomly selected. In order to save ourselves from imminent doom
we may have to hope future generations are NOT in our reference class. Tune in next week. Penny Lane notes that anyone believing in
a Goldilocks universe clearly never experienced English weather. Well, besides being a witty quip, this gets to an
important point: anthropic seletion only demands that our universe be able to produce observers
who think about the nature of the universe. There’s no reason they need to be in any way
happy about the universe they observe. In fact I feel like horrible English-style
weather may be strongly selected for. It encourages us to sit inside and think about
the nature of the reality. Regis Bodnar has a great point: while it may
be technically possible to observe a typical universe, it’s perhaps impossible to define
one. So, let’s see. How do we define a typical universe? Well it would be one whose particular configuration of fundamental constants gives you a universe similar in some respect to
lots of other configurations of constants. Honestly, that’s probably some massively exponentially
accelerating universe because the cosmological constant in most universes seems likely to
be a lot higher than ours. So a typical universe is mostly empty Singapore Breaking News likes to play space
time loudly so mom thinks they’re getting more brainy but in the background is playing
games on steam. Well, jokes on you Singapore Breaking News – that is
a brainy trick, so you got smarter despite yourself.

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  • Reply Jose Lopez December 5, 2019 at 5:10 am

    I haven't done an ounce of research on the subject, but you're wrong.

  • Reply Jose Lopez December 5, 2019 at 5:12 am

    Even science has reboots.
    Planks Analysis 2

  • Reply M Glover December 5, 2019 at 5:12 am

    If you haven’t done this already, check out Space Time VR. You won’t regret it.

  • Reply justin harris December 5, 2019 at 5:18 am

    Pray for your boy he needs to get a B in both Calc 3 and physics finals next week. Any tips would help.

  • Reply Lee Sailer December 5, 2019 at 5:40 am

    um. you have a chicken on your shirt.

  • Reply Tattle Boad December 5, 2019 at 6:04 am

    any piece of matter can be divided unto infinity

  • Reply Gustav Gnöttgen December 5, 2019 at 6:04 am

    Is finite infinitely smaller than infinite? Isn't it rather ∞ – n ?

  • Reply Balaji Kartha December 5, 2019 at 6:59 am

    this is really the big question – and I will be surprised if we find evidence to either of the suppositions in our lifetime!

  • Reply RangerBubbleGum December 5, 2019 at 7:03 am

    How can something be infinite if it started very small (Big Bang)? Can someone explain?

  • Reply Cesar Zayas December 5, 2019 at 7:35 am

    If we ever find the slightest curvature if the universe and calculate you would be able to use that information to tell you big the universe actually is

  • Reply Sewer Man December 5, 2019 at 7:41 am

    Imagine that you died and you're conciousness escapes through your physical body.You start moving through space at an intense speed,out there in the dark void after so many stars and planets and just awe all alone. You finally come upon nothing but just pitch blackness there you will suddenly start to feel a sensation of being heavy and start to fall downwards.

  • Reply rhino ranger December 5, 2019 at 7:52 am

    Lord Kelvin : “There is nothing new to be discovered in physics now.”

    Physics : “hold my ……”

  • Reply Pimpmastahanhduece December 5, 2019 at 8:00 am

    Due to low but nonzero quantum probability in an infinite spacetime, doesn't theory suggest that if you go far enough in any given direction you will eventually run into another world exactly in an equivalent phase wavefunction for the local observable universe compared to our observable universe? One in which you arrive to take your doppelganger's place exactly as you both left your respective things some time after they leave? Surely then they too will experience the same exact thing again to another identical locality but without changing the common vector. If someone chooses to turn 180 back of their own accord or perhaps a WELL randomized selection en route, it means the universe is either infinite or goes on further, but if you can confirm that you do in fact sort of come up behind your own ACTUAL normally backtracked addressed home locality, then shouldn't that estimated distance be the effective tunneling horizon and our relative "other side of the cylinder" that needs tape to hold together a positive curvature?

  • Reply Marcus Boswell December 5, 2019 at 8:16 am

    Astrophysics is my favorite philosophy!

  • Reply BlueFrenzy December 5, 2019 at 8:26 am

    Remember: if the universe is infinite, there are infinite places exactly like our observable universe across it. So all of you are infinitely replicated across the universe. And, on top of that, there are also infinite small variations replicated infinite times. So, there is a better PBS space time elsewhere presented by scarlet johanson, like it or not.

  • Reply rex mundi December 5, 2019 at 8:37 am

    By definition there is nothing other than the universe so it can't be finite. Finite implies an end beyond which something else exists. Finite in terms of the universe is a nonsense term.

  • Reply Erik December 5, 2019 at 8:41 am

    So, i just was looking at the big slurp theory. Is this saying that Dark Energy and the universe expanding faster and faster, is because outside the visable universe has a lower vacuum than our universes empty space….thus our universe is basically disapating into this other universe…and when it reaches us our physics will alter….. destroying everything

  • Reply Sandor Clegane December 5, 2019 at 8:48 am

    I'm not listening to a "scientists" with a t shirt on and no glasses. Where is the corn cob pipe? Where are the patches at the elbows of his jacket? He looks more like a fan at a Korn concert than a scientist.

  • Reply Kenny Thawsh December 5, 2019 at 8:48 am

    I always kinda though the idea of a flat universe made no sense. I may be heavily misunderstood here. But if I look up at night I see stars. I go to the opposite side of the planet I see stars. I go to any one of these stars and look out in any direction. Up down left right. I see stars. Wouldn’t that mean it’s not flat…? Lmao I must not understand the definition of flat very well

  • Reply Dustin Barlow December 5, 2019 at 8:50 am

    Paaaah we humans are much to intelligent for these simple questions! We are much to focused on much more important questions like who in the world is a racist?! Or why aren't women cast in every movie ever made?! Truly enlightened stuff!

    The aliens actually came down, and after trying to figure out what the hell is all this BS we humans focus so much on…. they shrugged their shoulders and left…. As they pulled away, they saw me in the rearview spaceship mirror, running after them like some abandoned child… tears streaming down my face, screaming "PLEASE FOR THE LOVE OF GOD TAKE ME WITH YOU! WOKENESS IS DISSOLVING MY BRAIN!! I CAN'T LISTEN TO MEDIA RIDICULOUSNESS DISGUISED AS INTELLECTUAL DISCUSSION ANYMORE, AHHHHH THE PAIN!!"…..

    (News comes on) "Tonight the top story, an Gay man, said a 'mean' white man bumped into him but didn't say "Pardon Me"!
    The white man is now facing the death penalty"


  • Reply Nazgul Linux December 5, 2019 at 9:06 am

    Dark energy needs to be supported by direct empirical evidence before it can be used so casually as a validated property of this universe. There are too many assumptions that these universal geometries are based upon and that is a major problem.

  • Reply Jay Koerner December 5, 2019 at 9:15 am

    Infinitely smaller then infinite just means finite, it could be quadrillions upon quadrillions o times large then the visable universe and still be "infinitely smaller" since that describes anything less the the smallest possible infinitely

  • Reply Jason Embry December 5, 2019 at 9:51 am

    How about the universe radiates out from a 4D point into a 4D sphere and doesn’t have to collapse in on itself? Like a 4D balloon blowing up

  • Reply Snowy 765 December 5, 2019 at 10:31 am

    Is the universe curved or flat? Could it be both depending on locality?

    The best analogy I can come up with is like water flowing around a rock. The flowing water is the expanding universe, the rock is an area of dark matter/energy, but the universe is so vast our observable universe is only one drop of water. So from our perspective the universe appears flat but there might be a slight curve that it is barely observable. To another observer, further round the “rock” the curve may be more pronounced. To another no where near the “rock” the universe appears flat.

    All we need to do is come up with a form of travel that will allow us to go to the edge of our observable universe instantly so we have another perspective. Sounds easy enough

  • Reply Novastar (SaberCombat) December 5, 2019 at 10:35 am

    In the distant past, I actually understood some of these…

    Now… omg… the latest (like 5-10) videos have been SO bloody far over my head–I just have no idea what the HEEEYYYLLLL is goin' ON! 😀 I am simultaneously OK with that and also not OK with that, too! 😀


  • Reply Tony Mahony December 5, 2019 at 11:03 am

    Who am I fooling? I was lost at around 00:19, but kept watching, cause it sounds pretty interesting

  • Reply Kettenhund31 December 5, 2019 at 12:33 pm

    So thinking about your descriptions, it seems to me that we live in a finite positively curved spherical universe with an infinite diameter……. Or am I missing something?

  • Reply om wadera December 5, 2019 at 1:05 pm

    I want to challenge you with something
    Is fire an anti matter?

  • Reply Pha Q December 5, 2019 at 1:06 pm

    Everybody knows the universe is doughnut shaped.

  • Reply Kamel Labiad December 5, 2019 at 1:06 pm

    This channel is dead the day they fired their graphic designer

  • Reply Cw Sayre December 5, 2019 at 1:20 pm

    There are NO "if's and buts" if you believe in our Lord and Saviour, Jesus H. Christ.

  • Reply Matthew Garth December 5, 2019 at 1:39 pm

    My theory In terms of the known universe it's possibly finite , there might be a limit to what we will ever understand but outside that infinite.

  • Reply Cha Kra December 5, 2019 at 1:59 pm

    It’s definitely unknown physics—what do we human brained specs of dust think we know or can ever know of absolute reality of our universe? The only thing we know that really matters in a galaxy far, far away is baby Yoda ?

  • Reply Charlie Miller December 5, 2019 at 2:22 pm

    It seems like our universe can't infinitely large without being infinitely old. Its not infinitely old, so its not infinitely large.

  • Reply Šimon Rataj December 5, 2019 at 2:40 pm

    According to the anthropic principle, it’s infinitely more likely we’re living in an infinite universe, because theoretically, one infinite universe contains infinite number of intelligent life forms, whereas one finite universe contains finite numbers of intelligent life forms, infinitely less than one infinite universe.

  • Reply Eric Matthews December 5, 2019 at 3:08 pm

    Nothing REAL can be INFINITE.

  • Reply AlphaCore December 5, 2019 at 3:25 pm

    Is The Universe Finite?
    next question.

  • Reply Tim Q December 5, 2019 at 3:28 pm

    so we observe acceleration in the universe…instead of trying to perceive it as acceleration away from the big bang, is it possible we are accelerating toward the big crunch on the opposite side of the cosmic sphere?

  • Reply JiveFowl December 5, 2019 at 3:34 pm

    Shout out to the compositors/artists that bring SpaceTime to life! Most people wouldn't notice that Matt was correctly colour timed to the background, but I did! Great work, as always! Keep it up!

  • Reply Zak ! December 5, 2019 at 3:43 pm

    That T Shirt…. LOL

  • Reply Vape Halla December 5, 2019 at 4:22 pm

    Is it possible for something like the local vacuum energy or the local Higgs field strength to be variables which are dependent on and proportional to the density of interactions in a given location?

  • Reply User One December 5, 2019 at 4:41 pm

    Lol imagine being stuck in a place where there are only three spacial dimensions. What a jail that would be!

  • Reply Asgeir December 5, 2019 at 5:44 pm

    Can we finally put the currently hypothesized depressing ultimate fate of the universe to rest now?

  • Reply totalfreedom45 December 5, 2019 at 5:50 pm

    Is our awesome universe finite, infinite, flat, curved…? Max Tegmark's book is revolutionary: Our Mathematical Universe: My Quest for the Ultimate Nature of Reality.
    Daring, Radical. Innovative. A game changer. If Dr. Tegmark is correct, this represents a paradigm shift in the relationship between physics and mathematics, forcing us to rewrite our textbooks. A must read for anyone deeply concerned about our universe. —Professor Michio Kaku
    ? ☮ ? ?

  • Reply Gamergosu December 5, 2019 at 6:07 pm

    theres always, whats beyond, do you hit solid rock, whats beyond that, theres nothing you come back at start point when touching end point?

  • Reply Katana Steel December 5, 2019 at 6:12 pm

    so does a 4d sphere a center?

  • Reply alex taws December 5, 2019 at 7:14 pm

    oh my god, I am so so happy!!! this is the first time (that I am aware of) that the significance testing procedure is being interpreted correctly!!! (in a video to the wider public)
    the first time the term "99% confident" was used I was really disappointed, that physics has fully jumped on the "significance" and "confidence interval" train…

  • Reply BattleModeBainbridge December 5, 2019 at 7:19 pm

    With so many things in nature having a curvature or roundness it always seemed so odd to me that the universe was supposedly flat.

  • Reply Daniel Smyth December 5, 2019 at 7:21 pm

    If it had a beginning, it has an ending.

  • Reply Nameis Metatoo December 5, 2019 at 7:25 pm

    What if the universe is the 3d surface of two expanding, 4d hyperspheres intersecting? Suppose one hypersphere contains only matter, and the other contains just antimatter.
    Each has an equal amount and constant (but not necessarily equal) density of matter or antimatter. If the matter hypersphere is smaller than the antimatter hypersphere at the time they intersect, then the result would be a higher density of matter; just as we observe in our universe. This also explains the accelerating expansion. The two spheres at the moment of intersection form a singularity with some amount of matter and antimatter. As they expand, this point would also expand.

    I'd be interested to hear others' thoughts on this!

  • Reply Brennon Robinson December 5, 2019 at 7:25 pm

    Maybe space is exactly what we call it, space. It's a space for things to happen. A tear, an opening in the fabric of something greater. A hole. A blob. A blob in What, Pure Energy? A blob of space where all the elements of pure energy can be split up and reassembled into a variety of things.

  • Reply Russell Subedi December 5, 2019 at 7:46 pm

    When they say positively curved, are they talking about 3D space or 4D spacetime?

  • Reply Vape Halla December 5, 2019 at 7:52 pm

    Am I missing something, or do we have a reason to suspect that various physical constants can differ, even in a multiverse model? Did we discover the properties that produce these constants?

  • Reply Mobius Trip December 5, 2019 at 7:54 pm

    There may be a crisis for Cosmology, or even science itself, but there will never be a crisis for the Universe.

  • Reply Chris Crook December 5, 2019 at 7:58 pm

    Everything that has a start's has an end doesn't it?

  • Reply clykke December 5, 2019 at 8:11 pm

    Question: Why is it that a FLAT but FINITE universe is always completely ruled out (and never mentioned)? I understand that such a universe would have some kind of boundary, beyond which space or time just doesn't exist, and that such a scenario would make most scientists uncomfortable, but I assume there is some other more scientific explanation for why the possibility is not even considered? No one seems to ever address it.

  • Reply Sketchbro_Luke December 5, 2019 at 8:11 pm

    It may appear infinite compared to our relatively tiny size. But logically if the universe began from a singularity and is expanding, then the border limits of the universe should be where the big bang has expanded to currently.

  • Reply KINN 1 December 5, 2019 at 8:42 pm

    Is it possible to see light travel trough space as beam say from a quasar and does the beam coming off the quasar tail off ie curl from the spinning motion flipping tennis problem too

  • Reply Kliersheed December 5, 2019 at 8:43 pm

    so what if the dark matter is just the matter that was faster than light, growing in mass/slowing down time, shrinking, and curving space even more until it broke through the positive curved universe and went into the negattive curved universe (inverted one) ? so we can still feel itsg ravitational influence from the "inverted side" but can no longer perceive the actual matter ?
    maybe its not that matter cant be speed up to lightspeed maybe its just to high in energy at that point to be contained in our "perceptable" universe ? to much for the space as we know it , to hold it in ? – i just feel like its fucking akward that there is a maximum speed in the universe. thats so annatural.

  • Reply Daniel Smyth December 5, 2019 at 9:06 pm

    An idea for a show could be about the "Cycles" and "Periods" of the Universe. If you could Step Up far enough, would the universe look just like a nebula?

  • Reply Kliersheed December 5, 2019 at 9:25 pm

    imagine the sign of infinity (the eight)
    and now imagine one side is the "positiv curved" universe, containing everything that has lower speed/mass than black holes(mass) / light (max speed)
    and now imagine everything with mass that gets faster than light or gets higher mass than a black hole, breaks the limit of our positive universe (like smth that can no longer be supported by the water surface) and breaks into the negatively curved universe (the otherh alf of the eight). so to say an inverted version of space. that would explain why speed up mass shrinks (if it shrinks o infinity it has to grow at some point, but will no longer be in our space) and why light cant leave black holes.
    and also gravitation travels through space (just like light goes through water) and thats why those two halves (of the eight) are still overlapping and we can notice the mass on the other side as dark matter. not seeing it (because its in the other space) but still feeling it having another impact on the stability of our universe.
    also the crossing point of the 8 would be where the universe is theoretically flat? or better saidi ts just a point ? a point where all information of mass gets reduced to one quantum particle that holds all information simultaniously ? which is also where the universe started out as ? in the crossing point ?
    mathematically you could say by expending into bove sides of the eight (symeteric + and – ) it has in its sum 0 expension so the negative universe (space) stabilizes the positive universe (space).

  • Reply Toni Bavčević December 5, 2019 at 9:40 pm

    is our universe inside black hole ?

  • Reply Aquila Rossa December 5, 2019 at 9:48 pm

    I think the key to answering this question is to understand what space itself it. Is it an empty nothing that existed before the expansion of matter in the universe? Matter requires space in order to function as matter in the ways we observe. Even an atom is comprised mostly of space and its particles require that space in order to behave as that atom. I am wondering if space is integral to matter. The existence of one requires the existence of the other. That means there will be space wherever matter is or has been. I wonder if the outer reaches of the universe see space being expanded as matter pushes further out from its point of origin. Absolute nothing would not only be the absence of matter, but also the absence of space for that matter to exist in. That would be a finite universe.

  • Reply Igor Sawicki December 5, 2019 at 10:02 pm

    You could make a video about this topic when we will know for sure if it's confirmed or comes to be false.

  • Reply annakeye December 6, 2019 at 12:04 am

    Singapore Breaking News comment reminded me of a trick I used to pull in high school. When in the library, if I saw a teacher coming, I'd pick out a book like 'War&Peace' (if it was an English or Social studies teacher) or if it was a maths or science teacher, I'd pick up something along the lines of a Feynman or Sagan publication. Of which there were perishingly few. It was only as an adult that I realised that knowing that these books existed showed I wasn't a complete idiot in the first place. Next report came out saying about the high standard of reading material I was choosing.

  • Reply fartzinwind December 6, 2019 at 12:18 am

    The universe is rather indifferent to your comfort.

  • Reply MorbidManMusic December 6, 2019 at 12:18 am

    It's can't be "infinity smaller" than what we thought.

  • Reply Karolis December 6, 2019 at 12:41 am

    It looks weird how he reads
    Tele prompter

  • Reply black.c5 December 6, 2019 at 1:17 am

    If the universe ended, then what would be beyond that? Mind boggling

  • Reply John Doe December 6, 2019 at 1:46 am

    I forgot is the universe last thought to be 92 Billion years wide in just 6 Billion years? With inflation starting at 0.01 seconds? Point is, what do you envision as infinite, but I have to say that as far as we know now no it is not.
    Most employed physicists debate ideas they have pondered while working to which they themselves can't resolve

  • Reply Mad Hatter December 6, 2019 at 2:22 am

    Pea brains simultaneously claim the universe is infinite and 14.5 billion years old.

  • Reply L Christian December 6, 2019 at 2:41 am

    Yes, it is finite! 26 Billion year cycles, actually:

  • Reply tanya December 6, 2019 at 2:50 am

    Lol I liked the tin foil hat during the flat earth bit. Though I doubt any real flat earthers watch space time.

  • Reply Brent Pearson December 6, 2019 at 2:59 am

    If, ifs and buts were candy and nuts we'd all have a merry space time?

  • Reply Roland Lee December 6, 2019 at 3:07 am

    And thus the Sphere Universe Society begins…

  • Reply Døctøred Plague December 6, 2019 at 3:53 am

    There was a beginning to this part of time in the universe's infinite life. But there was no beginning the "Universe" has always been here, will be here from the big bang to the "crunch/rip" before and after. Everything that can happen will happen, just in parts. Whatever we're in is happening right now.when the universe "ends" sooner or later… However it starts it will, by blowing up and going back together, and blowing up, and going back together forever and forever… Wonder wholl ill be after i die?

  • Reply Matthew Branson December 6, 2019 at 4:04 am

    Do some ACID and then talk to me about the universe.

  • Reply Glass Menagerie December 6, 2019 at 4:09 am

    C'mon team hyper donut! Finite universe supports "big bounce" theory… contradicts multi-verse (in my opinion).

  • Reply free thinker December 6, 2019 at 4:24 am

    ok lets change perspective ! is 100% nothing infinite or finite or non of the above? what about 100% something ? is it finite infinite or non of the above?

  • Reply free thinker December 6, 2019 at 4:29 am

    knowing what i know about pc ? i select 3 and no they did the job correctly but they ignored a picture from nikola tesla ! and this affect everything in 2019 ! i just tested on my own pc and made fair gain in a metric for a simple trick lol . no i didnt mod everything too time consuming !but i made enough change to become aware of the issue is real

  • Reply free thinker December 6, 2019 at 4:34 am

    as hardware , firmware software stand right now ? classic science wont get their wish ! it require a massive change in modus operandi . unless they want to do everything by hand . i would start with the coffee stain experiement success and failure and finding out the why ! this should give science the clue they need to see the issue ( i doubt very much that classic science will have it fixed since the issue come from who ever make the hardware

  • Reply free thinker December 6, 2019 at 4:36 am

    from all hint i saw? nope the universe isnt closed

  • Reply free thinker December 6, 2019 at 4:38 am

    i doubt classic science can see the error ! i mean one of those error i notice ? i was in a restaurant day dreaming when i noticed it. its so subtle if i had been looking for it i wouldnt have noticed it

  • Reply free thinker December 6, 2019 at 4:38 am

    i dont think it is science error per say . its tool error

  • Reply Harold Slick December 6, 2019 at 5:21 am

    [Insert Issac Asimov quote here]

  • Reply Mark Levin December 6, 2019 at 5:29 am

    If the parameters determining the flatness of the universe are a continuua wouldn't the probability of a perfectly flat universe be zero?

  • Reply John Wilson December 6, 2019 at 5:29 am

    big Bang….lol

  • Reply James Elger December 6, 2019 at 5:59 am

    It's saddle shaped if anything for as long as it's expanding. Think about it, it has to be.

  • Reply Urabusu December 6, 2019 at 6:10 am

    I always come back hoping to not see this guy gesticulating on screen but my hopes are always dashed. Please get him off screen. Voiceover is fine for this stuff. In fact it's preferred.

  • Reply Pale Dale December 6, 2019 at 6:18 am

    Are you Russell's Brand's brother ??

  • Reply Deane Simpson December 6, 2019 at 6:30 am

    Considering the variables that go into calculating the curvature of the universe, it seems infinitely improbable that the answer would come out to be exactly 1 unless an unknown property demands that the universe be flat and influences the associated parameters.

  • Reply Old Guy December 6, 2019 at 6:48 am

    Our galaxy is probably like an atom compared to the backdrop of space.

  • Reply ••• December 6, 2019 at 7:25 am

    I still think our universe is a black hole, and our perception of expansion is actually the impossibly small matter within it (us/our galaxy) collapsing inward, on time/space scales no more comprehendable to us, than our 80yr lifespan is to a photon. This would also mean the 'dark matter/energy' problem, is our abstract perception of empty space, being infinitely dense. Maybe the microwave backround, is the inverse of an event horizon. Always made sense to me.

  • Reply Curt Weil December 6, 2019 at 7:37 am

    Haha the big bang. Dinosaurs. Space. All such malarkey and theoretical Science pushed as fact to impressionable children. Sad

  • Reply Jack Jones December 6, 2019 at 8:05 am

    What I don't understand is that if the universe isn't infinite, then what is it inside of, or how could there be nothing after it?

  • Reply Radu Hociung December 6, 2019 at 8:22 am

    Can it not be curved like a parabola, so still open, and therefore infinite?

  • Reply Light Owl December 6, 2019 at 8:48 am

    Yes the Universe is One and Infinite, the binary language of true nature. Also the value of a sphere.

    Equal opposites simultaneously at the very source or core of life. Everything and Nothing or Matter and Anti-matter, Light and Dark etc.

    Hot and Cold for instance, if you get hot you need to cool and if you get cold you need to warm up. This is why things have to be the way they are but it does not mean we should be evil after being good, it's just that it cant happen but good is greater than evil.

    Finding balance for yourself, realising the core, then you will learn so much and instinctively know which is the right path. Doing good the right thing always, no evil.

    The equal oppo of a sphere is the torus, if you unlck this key of understanding nature you will become enlightened beyond your belief.

  • Reply Karasamune December 6, 2019 at 8:49 am

    If the universe was flat, how would we move 3 dimensionally within it? Wouldn't we only have lateral and vertical movement? Honest question

  • Reply Hakuna Matata December 6, 2019 at 9:03 am

    Nothing in the real world is of infinite magnitude, nor absolutely zero. Infinity and zero are very handy mathematical constructs, useful for simplifying equations, and they exist only in the abstract.

  • Reply liran sindel December 6, 2019 at 9:04 am

    man, I dislike those informal videos that you just see a dude explaining rather than pictures or animation..

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