But if the universe is expanding, doesn't that mean that the density of atoms in a given space decreases? Will the universe one day be much more concave than it is today?
Yunpeng Liu That’s an interesting question. I think the answer may be no. If you consider the tools which we have on earth, which is a curved surface where we exist and seems like a reasonably analogous to living in a curved universe, then you can see that the tools which we have are able to measure the curvature of the earth. If you want a way that you can test that at home, take a globe and choose any three points on the globe. If you draw the shortest line between each of the points and create a triangle, then you can use a protractor and measure the internal angles and sum them in the same way shown in the video. While an impractical method for us to use on the earth, it should still scale if you get creative.
@@joshuareich580 Yes and you are right, but only in limited cases, which in your example is measuring 2D using 3D tool. Imagine you only have a perfectly flat protractor with mathematically 0 meter thickness and it only dwells on our earth surface which also has height of perfect 0. Then you can only have a "curved tool" as so to speak since the hosting space is curved. Would you know that the three angles together are more than 180 degrees? I guess not, because a 46 degree in 3D matches 46 degree angle perfectly in 2D but your tool reads 45 degree. Our world is exactly in that situation. We are using 3D to measure 3D, but we can only see the curvature when we jump to 4D. Hope I articulated well.
@@suwuliu5232 The way we measure curvature is by looking up into the sky, at the Cosmic Microwave Background radiation. In other words, we measure how the universe was in the PAST. Thus, we know that any possible limitation of measuring curvature due to being "in" the curvature will not affect our ability to calculate whether or not the space we live in is curved.
@@suwuliu5232 It is perhaps hard to visualise but we can in fact measure curvature without worrying about our tools being too curved. The usual way to explain this is using geodesics and triangles but it is hard to see why this avoids the problem you describe. We can solve this by thinking a little more mathematically though. The Gaussian curvature of a surface is intrinsic meaning it depends only on the surface itself and not on any larger space we embed the surface into. Similarly for any "pseudo-Riemannian" manifold (such as space-time) we can define an appropriate idea of curvature that depends on the "pseudo-Riemannian" metric. Put simply, this metric is how we measure angles on the manifold and it is a infinitesimal tool (that is, it acts on the tangent space, which is flat). TL;DR: We measure angles on a flat space tangent to the manifold and so the tools don't have to be curved.
But as the universe is expanding, this density should change constantly, right ? so a few billion years ago, it was not flat - because the density of the universe was higher - and a few billion years later, it won't be flat anymore ? If this is the case, it's strange that I've never heard this reasoning before.
It's not really the matter density that's relevant; it's just easier to understand, given that we're made of matter. What's relevant is the energy density, which includes matter, radiation, dark matter, and dark energy. And as the universe has expanded, it has come to be dominated by dark energy. That's kept the energy density constant.
I don't think that's what is being portrayed in the video. I think the video's definition of expansion is extension, as in the dimensions of space are growing. This is in contrast to a stretch, where the matter inside space would also "expand", but I don't think this is what was meant in the video.
It's not the density that decides the curvature. What was used in this video with 4, 5, or 6 atoms was an example. Basically what it is is if there was 20% more or less matter in the universe the curvature would be different. Honestly using the example they did just causes confusion.
Galaxies and planets are round, because gravity, shape of the universe has nothing to do with it... It's like saying that your house is made out of bricks, so your entire house is shaped like a brick. (Sometimes it's true, but you get the point)
I guess that's why the calculations were done from data obtained just after the big bang. The universe had just started expanding at that point of time.
Akash Raj - Yeah, it doesn't work like that at all, all matter from the big bang remains within our cosmic horizon or has past over our cosmic horizon over time. We say that all matter was concentrated to a single point only because we have calculated that BACKWARDS from space we observe today. There is no reason to believe space was not larger than a point at the moment of the big bang and that the big bang occurred everywhere with the space simply forever beyond our cosmic horizon.
@@callumscott953 Cant we see `just` after the big bang by looking 13.8 billion lightyears away? That's how we know about the cosmic background radiation and using trianulatiom we figured out the univers is flat (as stated in the video)
ok, just to avoid the confusion, flatness of space does NOT mean the space is like a 2 dimensional plane... the idea of flatness comes from the fact that we are measuring the angles of a triangle on the EDGE of the observable universe. In other words, all it says is that the triangle we are measuring is flat! Hence, all we can conclude is that universe is immensely huge (loosely speaking, sth like a sphere with infinite radius)! basically another confirmation that our universe is almost limitless... so please avoid using the term flatness over here. Instead, the more accurate thing to say is that the EDGE of observable universe is flat.
Reza Madankan which doesn't really mean anything, since the universe doesn't necessarily end at the edge of our observation. Who's to say we won't start getting light from far more matter out there, or even far less than we were expecting?
Flat means 2 D and anything with thickness or depth is not flat you stupid fucks. If you doubt me look up the word flat in a official Webster’s dictionary. You stupid fucks are like the uneducated people in the dark ages who thought the earth was flat. In 700 years people will laugh at stupid mother fuckers who thought the universe was flat. DO YOU UNDERSTAND YOU GOD DAM NEANDERTHAL?????
I just want this to be seen cause I know no 1 will see my actual comment in a like a year Have u seen those videos when they put a bowling bowl on a round sheet and smaller round objects if space is flat u cannot go under anything other rise u would go under space itself unless we think of it as a graph with 3d objects instead of 2d shapes the 3d objects can look as far as I want them to look
Doesn't have to be 3D, there could be more spacial dimensions out there that we just cannot even fathom, but regardless of the amount of dimensions, yes, flat as in no curves.
Niels Rasmussen He's talking about curves with respect to the path of an undisrupted object. It would actually be counter intuitive to think that an object could essentially accelerate without an external force being applied to it, so we are essentially taught this principle from a very early stage in physics studies. The implications of space curvature are very interesting though. Imagine if you could permanently change an attribute of a finite region space so that the trajectory of objects passing through it is always predetermined.
The Flat Earthers are going to love this video. They may ask how can we have a round earth in flat space? So if space is flat the earth must be too 😳 😂😂😂
Answer: Time is depicted on *CURVATURE, BOI!* in these lines of space’s expanse. SPACE is growing cuz particles are spreading. Since PARTICLES are spherical(perfect or not), the Earth. IS. ROUND. And so’s your head, get over it already!
You're fucking stupid. They just said it was flat. This comment would be funny if it was using double irony which only stretches the joke. I'm so fucking mad
"And yes the universe in constantly expanding" "then what is it expanding into?" "okay you just blew my mind" -Ferb internal conversion aka a children's show (Phineas and Ferb)
It's expanding internally. There is no outside to expand into. It's not like a balloon filling up, it's like the surface of a balloon stretching. If you draw two dots on a balloon and inflate it, the distance between the dots increases, but it's an increase in the internal distance of the balloon surface, not an increase into something.
I have just left my Cosmology class on Shape of space & I was VERY confused. I immediately searched fpr this and I feel enlightened. Thank you for explaining in the best way possible ❤
If the universe is expanding faster than light, in the edge because of time dialation, time is "frozen". And no matter how fast you go you can't go faster than the edge, your time would slow down. In the edge of the universe, it's like no time has passed since the big bang.
The end of space is unobservable -- light beyond the horizon will never reach our planet or our galaxy (since all matter is accelerating away from us)... So for all intents and purposes, it doesn't matter whether there is an end. Kinda beautiful if you think about it.
But, cosmological inflation is a widely accepted solution for the flatness problem. This video implies we have no idea at all why our universe might be flat, which seems plainly wrong.
Accepted as a plausible theory. I understand what you mean but it's hard to explain everything in 3 min. Also the "fuzzy part" before inflation is still difficult to model.
Inflation is an as of yet unproven hypothesis. To claim that it is fact or the correct answer is putting the cart before the horse. There are also several other hypotheses that match what we know thus far and as such are equally likely. They are also exclusionary. We need more observation and experimentation before we can build a sound theory for the flatness or expansion problem.
I thought Inflation explained why the universe was uniform in density. I don't think it explains why the shape of spacetime is flat. You could have a inflationary uniform-density universe with a bit more energy, and it would have positive curvature.
Well, duh! If you think about Earth and the rest of the cosmos as the result of one big fart [the big bang] you'll see objective, irrefutable evidence that all celestial bodies our teachers have told us are round, in actuality, are flat! Why? Because "flatulence" has the word "flat" in it, obviously. It all makes sense, the damn government lied to us all!
In addition, there is no way for us to know if we really viewed a significant portion of the universe, or we simply measured a small small area that therefore makes the universe seem flat, in a similar way that a triangle 100m wide would show the earth to be flat, while a triangle 2000km wide would prove it to be round.
That's why they say 'it seems to be', we may never know for sure. I mean we know that locally it's curved, also there is that Great Attractor drawing entire galaxies towards itself, so terms like local are on a whole different scale in spacetime. Who knows, maybe things work the other way around, and our universe "wants" to flatten, and that's the reason of the apparent perfect density, and not just some cosmic coincidence. Also, there is a chance that we got the wrong idea of something, did the wrong calculations based on that idea, and a lot of things we know might be simply wrong. Or maybe we are on the right track, but miss some crucial information. There is a whole slew of possibilities, luckily science is relentless.
2:30 My theory of why the universe has the exact amount of energy to be flat, it's just because if it were not that way then we would not be existing. Think about the conditions in which we would live, maybe some people do not think about it or pay attention but they have to remember how insignificant we are and the time we have living in this space-time.
but every coincidence is highly unlikely, so to add on to you, i believe there is many universes with every possible combination of everything and we happened to live in this one
The inflationary theory allows for a region of flatness the size, or bigger than the observable universe and still be extremely curved as we zoom out into the whole size, wish according to eternal inflation might be 10^(10^30) times larger than the observable universe.
In other words, the anthropic principle + many worlds interpretation. My hypothesis is that the net energy in the universe is zero. We started with nothing, but nothingness can split into positive and negative energy (like quantum foam). No matter how much you split zero into positive and negative matter/energy, we still get a flat universe. We would just be occupying the portions of space in which positive matter just happened to never cancel out with the negative. Antimatter could easily be repelled by gravity, dispersing into deep space.
The confusion comes from the fact that all diagrams of space time are originally 2d, and when manipulated 3d. That’s because space is entirely 3d when unaffected and 4d when manipulated by mass and dark matter, and you can’t really show people 4d space. It’s literally impossible to comprehend with traditional brains.
A flat universe implies an expanding universe with a decreasing velocity approaching zero. However, what we've seen instead is expanding universe with an increasing velocity due to dark energy. So unless matter is being created out of nothing somewhere, mass-density will continue to drop and become more and more negative. How are astronomers and physicists reconciling "flat" mass-density versus accelerating expansion? it seems to be a contradiction, as there is an ever increasing volume without a corresponding increase in matter (mass).
Dark energy and regular matter do not interact in normal ways. So it might be possible for Dark energy to cause the Universe to expand while having the universe retain it's shape. Also, the shape of our universe depends on the amount of matter, or mass and energy, and as far was we know, dark energy has no mass, and exerts no "normal" energy on regular matter. Note. The expansion of the Universe is a weird and not normal interaction of matter and dark energy. Please correct me if I got anything wrong! I'd love to continue this conversation!
Here are some diagrams that might explain better: www.schoolphysics.co.uk/age16-19/Astrophysics/text/Universe_flat_closed_or_open/index.html and upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Universe.svg/2000px-Universe.svg.png minutephysics says the universe is flat due to mass-density (omega) estimates being close to 1. But that is not what we observe when we measure universal expansion. What we see is a positive acceleration, which corresponds to an open universe: phys.org/news/2015-04-mysterious-dark-energy-universe-expansion.html So I don't understand if there are completing claims, or if minutephysics is just working with old data that was used before the discovery of an accelerating expanding universe and dark energy?
The scenarios you mention, and diagrams raven lord provided, assume no dark energy because they're older than its discovery in 1998. Here's an article and diagram about that scenario, which you can see was published in 1995. archive.ncsa.illinois.edu/Cyberia/Cosmos/CosmosFate.html
everything is designed perfectly, the more I know the more I get that this universe is not just a coincidence, there is a smart design and a designer beyond our comprehension.
Actually it is the hypothesis of inflation. There are many competing hypotheses about the early universe and how to explain what we see and why. We need more evidence before any of these can be a testable and predictable theory. When speaking in science it is only correct to use the scientific definitions for theory and hypothesis instead of the colloquial ones.
Andrea Teal Not really. Theory in science means it has significant backing based on observation and repeated experimentation. Scientific laws are theories which have undergone so much experimentation under so many different circumstances that they are now widely held to be true, and would require extraordinary evidence to disprove.
+AvalancheofNeed Sorry but that is not the definition of a scientific law. Scientific laws are expressed as mathematical formulas that describe how a phenomenon behaves. They do not attempt to explain any mechanism, just what is observed. They basically only state "this is happening and it can be described with this formula". For example, the Law of Gravity is not the same thing as the Theory of Gravity. en.wikipedia.org/wiki/Scientific_law
Humans would probably not exist. We are an amazing cosmic miracle, and very small changes to our solar system could mean no life on earth. Life is freaking nuts, dont waste it i guess lol
i read somewhere that earth has 2 moons, 1 is the moon that we already know, the other one is some kind of meteorite or something orbitting earth. I forget what the effects of the second moon does tho, look it up
What if, extra curvature in space causes anti matter to become transformed into an undetectable for of matter, stopping regular matter from becoming annihilated. Causing space to constantly balance itself toward a flat state while explaining both dark matter and why there exists more matter than anti matter. I must be right, I'm some random guy on the internet giving an off the cuff guess.
en.wikipedia.org/wiki/Baryon_asymmetry#Regions_of_the_universe_where_antimatter_dominates en.wikipedia.org/wiki/Annihilation Jokes aside about being a random Joe, it is indeed very unlikely as we probably should have already detected such disturbances. Take in account that curvature of space does not make two particles uncollidable, otherwise it would be a very radical property of space that remains undiscovered and would require a theory compatible with current knowledge, plus any missing positive evidence for whatever such theory predicts. Furthermore, you should already know that in it's verbatim sense, "undetectable" is a concept science is not anyhow interested, if that's what you meant.
this is pretty much the ‘fine tuning argument’ (fyi. hydrogen atoms per cubic meter are not the only fine-tuned values). You are absolutely right, that we can’t explain this in a testable way for now. I would like to highlight something very important tho: it’s not the universe that is fine-tuned for us, but rather we adapted to an already existing universe. Which obviously raises the idea that our universe might not be the only one.
Well being a follower of the anthropic principle, the reason we live in a specific universe is because we... well we NEED to be. Check the anthropic principal on youtube or wikipedia for a better explanation
Nestrislia Crystal how does the Anthropic Principle go against atheists? If anything, it totally removes the necessity for a god to exist for us to exist, and then we can apply Occam’s Razor, meaning that it’s more probable that the universe just came out of nothing than an arbitrary god coming out of nothing and then creating the universe.
Could we also find out the shape of space in some places like this: if we know the speed things like the sun, earth and moon orbit, then we can test on different shapes of fabric, have some balls on the fabric just scaled down and scale down the speed too and test all the shapes and see if they match? Flat fabric is often used to demonstrate gravity.
@@dabest8147 I think the original comment I replied to was deleted. For context it went something along the lines of "there are 5 atoms of hydrogen per cm^3 in space" and they tried to correlate that with the Fibonacci sequence :)
There is something out there that is way beyond what we can comprehend. Like this universe is just a tiny part of something that is so much bigger and only when we figure out what that is can we start to explain black holes and space properly. It’s the ultimate mystery
BakedBeans that doesnt seem cleverly. What a coincidence (!) That makes happen all life. And in this life only human can think on everything. There must be something we dont want to understand. We have to make an effort to understand the Real.
@@seyyidhansaroglu We are not basing off the coincidence as a 'mere' coincidence. We are indeed trying to find out the reason for this coincidence, although studies in that regard are still pretty illusive. Hence, we term it as coincidence to satisfy the momentary curiosity of ours.
For the people saying that it is not a coincidence it is not flat I want you to realize that everything had to go perfect for the first bacteria to be alive and it to not die by tomorrow If something is flat then is flat people are not asking why are elemental particles round and why do we still call something flat even do it has a lot of spheres in it It can be space-time is a weird thing we live in yet it is still able to be understand if you people stop using assumption and anologys because of you thinking it's "normal" nothing is normal and it dosent make sense so shut up and accept that something exists even do it dosent go to your opinion
We observe an effect that we call Gravitational lensing from relatively dense patches of the universe; this could be called convex lensing. It should be possible to have concave lensing with a torus of matter.
+Reckless Roges Hey I never thought of that. I read in Michio Kaku's Physics of the Impossible that negative mass does actually exist. Not sure about the validity of that but in principle, the negative mass should be able to produce a negative curvature on spacetime.
Vacuum energy is the energy of empty space. It is the most likely candidate for dark energy, though we don’t really know. However, I posted without thinking in saying that vacuum energy would cause negative curvature. I was momentarily confused by Henry’s video which gives a misleading picture. In fact, the kind of curvature he is talking about in the latter part of the video - the global curvature of space - doesn’t actually have much to do with energy density contrary to what he says. It is an intrinsic property of space time. Basically, in cosmology we have an equation which governs the evolution of the universe (Friedman equation, which is actually an applied version of the equations of general relativity). On one side we have the properties of space time: the rate of expansion and the curvature of space, and on the other there is the energy density of matter. If the curvature part is zero, corresponding to a flat universe, then the rate of expansion is directly proportional to energy density. Cosmologists like to use this case as a reference and so they define a quantity called critical density which is the kind of density that evolves proportionally to the expansion rate. In other words, it is how the density would evolve in a flat universe. So the point is not that there is some magical number for the energy density which makes the universe flat, but rather there is some relationship between how density evolves with respect to the expansion rate that is different in a flat universe compared to a curved universe.
This is gonna be a long one so strap in One of two options are possible about the universes origin. 1: We are the only universe If this is true, we have won the cosmic lottery by being alive, just the rules of the universe being how they are because of all things that could happen, our world happened. If this is true, we must live our lives to the fullest 2: We live in an infintly sized multiverse This makes sense as A; In the CBR of space, we can see a cold spot that would make sense if another universe bumped with us; and B; Universe's can be made in pairs. If string theory is right, then our universe is just one huge string and during the big bang we collided with another universe-string. This makes even more sense as the equation "Energy= Mass (of object)× [300,000,000 mps²]²," and antimatter collisions being 100% efficient mass-energy converters would make it so that if we collided with an antimatter universe-string and it wasn't perfect, we would have our
Excellent representation. The term flat throws me off. I’m a layman so for me flat basically means two dimensional plane with x y coordinates. But when physicists say flat they mean essentially x,y,z coordinates on an axis. Flat planes intersecting like a cosmic grid naturally square until energy creates matter which then bends space creating gravity or rather the ability to experience gravity. The bending and morphing of space creates events that can be described as traveling in the 4th dimension which is time. Got it.
We cannot be in a simulation, because that doesn't explain consciousness. Consciousness is no 'illusion' of a physical reality... Perhaps astonishingly - because we all simply assume it's real - there is no objective scientific evidence for a physical reality. Physical reality is an illusion of consciousness. www.scottowen.org/topic/luciddream
Wait if I remember correctly, according to Einstein's general relativity the space is flat but it curves on itself because of the gravity it exerts on itself, right? So the best way to describe the universe is actually the Pac-Man way...
hahahah that's funny, someone else said I have a pancake butt so I made an entire video dedicated to them. I'm starting to wonder if mine really is flat though.
lol Benjamin, I was hoping you'd say that your original comment wasn't actually directed at me...butt knowing that you spent your time to watch one of my videos just to see what my backside looks like has given me a good chuckle.
fun fact, in space with negative curvature, there is a _maximum size_ of triangle. for a given constant negative curvature, there is some area for which it is impossible to create a triangle with greater area than that
I don't think I really understand. So "flat universe" in this case does not refer to the dimensions we perceive the universe to have, but rather to how the space is distorted? Like, "flat" means that space is by default not distorted (though gravity does distort it and since gravity has no range as such everything is in some way bent and curved and rippled). Is that correct?
Quickburger9000 Deal with it. Take for example the hyperbolic plane H^2:={(x,y) in R^2 | y>0 } with the metric g_ij(x,y)=1/y^2. This gives you a 2 dimensional riemannian manifold that has constant curvature of -1
Quickburger9000 Deal with it. You could also take the pioncare-disc as an example but as far as i know there is an isometric isomorphism between those two and thus they are pretty much the same
o O 0 We can't know if we live in the "real" reality or not and we'll never be able to tell what the "real" Reality truly is. It could all be a simulation inside a simulation inside a.... and so on.
I honestly believe that there is no way that everything that exist is just perfect for no reason or it’s just coincidental, intelligent design is clear and litterally stares us in the eyes taking up all space we can see and yelling infinitely “i am here!” Like horton and The Who’s.
![Gunna - HIM ALL ALONG [Official Visualizer]](http://i.ytimg.com/vi/HiCxoDeo0hc/mqdefault.jpg)
But if the universe is expanding, doesn't that mean that the density of atoms in a given space decreases? Will the universe one day be much more concave than it is today?
Dalriad that's a good question. Let's get this up there so Henry can see
yea thats a very good question
+
Exact same question came to me. #FollowupVid
Dalriad This is what happens when u try to explain something complicated without math in 3 minutes video.
Flat earthers after watching this video: the universe is *round*
Lucas Meneses lmao
Well I mean technically, don't they have that space dome thing?
lol. Too true.
Bold of you to assume flat earthers would watch this video
@@pblpbl3122 You never know.
This video is so wrong, the correct term for negative curvature is "pringle"
Mmm. Pringles.
This makes me want to eat a black hole
Finally, someone who gets it.
You're God damn right! :D
He may have used some different terms to make more sense and to not entangle things up...
*Perfectly balanced. As all things should be*
Perfectly balanced +- 0.004. So not really perfectly.
Reddit moment Edit: Thanks for the gold kind stranger!
*Are
Thats assumimg everything is finite
thats why thanos is never wrong
Great, now we have to worry about flat spacers.
azdgariarada lol
Wouldn't that be round spacers?
azdgariarada
I am a potato spacer
SuperNuclearBoss 1337
Count me in
not planet flat as you would think, but space is flat, not the objects. But ha! And Columbus made my birth possible, so I owe it to a murderer
HA TAKE THAT ROUND SPACERS
- Flat Spacers
-science discussions in future... :d
Incredibly underrated comment. Hats off to you, sir!
Julius Javellana
Duuuuude, you're so on to something NASA lies.
Jay slash Kay
Or just have a lot of screenshot material.
Wait a minute, are you talking about AtomZadra?
1:01 can you see grey dots on intersection of line.....Illusion....
Holy sheet
omg yes!
ILLUSION 100
Yup
Justin Y clone
but when the space is curved, wouldn't our measure tools also curved to a same degree so that we can't tell?
Yunpeng Liu That’s an interesting question. I think the answer may be no. If you consider the tools which we have on earth, which is a curved surface where we exist and seems like a reasonably analogous to living in a curved universe, then you can see that the tools which we have are able to measure the curvature of the earth.
If you want a way that you can test that at home, take a globe and choose any three points on the globe. If you draw the shortest line between each of the points and create a triangle, then you can use a protractor and measure the internal angles and sum them in the same way shown in the video.
While an impractical method for us to use on the earth, it should still scale if you get creative.
@@joshuareich580 Yes and you are right, but only in limited cases, which in your example is measuring 2D using 3D tool. Imagine you only have a perfectly flat protractor with mathematically 0 meter thickness and it only dwells on our earth surface which also has height of perfect 0. Then you can only have a "curved tool" as so to speak since the hosting space is curved. Would you know that the three angles together are more than 180 degrees? I guess not, because a 46 degree in 3D matches 46 degree angle perfectly in 2D but your tool reads 45 degree. Our world is exactly in that situation. We are using 3D to measure 3D, but we can only see the curvature when we jump to 4D. Hope I articulated well.
@@suwuliu5232 The way we measure curvature is by looking up into the sky, at the Cosmic Microwave Background radiation. In other words, we measure how the universe was in the PAST. Thus, we know that any possible limitation of measuring curvature due to being "in" the curvature will not affect our ability to calculate whether or not the space we live in is curved.
@@suwuliu5232 It is perhaps hard to visualise but we can in fact measure curvature without worrying about our tools being too curved. The usual way to explain this is using geodesics and triangles but it is hard to see why this avoids the problem you describe. We can solve this by thinking a little more mathematically though. The Gaussian curvature of a surface is intrinsic meaning it depends only on the surface itself and not on any larger space we embed the surface into. Similarly for any "pseudo-Riemannian" manifold (such as space-time) we can define an appropriate idea of curvature that depends on the "pseudo-Riemannian" metric. Put simply, this metric is how we measure angles on the manifold and it is a infinitesimal tool (that is, it acts on the tangent space, which is flat). TL;DR: We measure angles on a flat space tangent to the manifold and so the tools don't have to be curved.
Holy SHIT !!! NASA should Phone you
But as the universe is expanding, this density should change constantly, right ?
so a few billion years ago, it was not flat - because the density of the universe was higher - and a few billion years later, it won't be flat anymore ?
If this is the case, it's strange that I've never heard this reasoning before.
It's not really the matter density that's relevant; it's just easier to understand, given that we're made of matter. What's relevant is the energy density, which includes matter, radiation, dark matter, and dark energy. And as the universe has expanded, it has come to be dominated by dark energy. That's kept the energy density constant.
The universe expands with the matter, which is part of the universe, so the density is the same
I don't think that's what is being portrayed in the video. I think the video's definition of expansion is extension, as in the dimensions of space are growing. This is in contrast to a stretch, where the matter inside space would also "expand", but I don't think this is what was meant in the video.
It's not the density that decides the curvature. What was used in this video with 4, 5, or 6 atoms was an example. Basically what it is is if there was 20% more or less matter in the universe the curvature would be different. Honestly using the example they did just causes confusion.
Offstar1029 didn't he give a density though? 4 5 or 6 atoms per cubic meter
Real universes have curves!
Roboblade604 Yes they’re thicc
But i think space is circle because if you look all the stars and planets are round.
Even galaxies are round
Galaxies and planets are round, because gravity, shape of the universe has nothing to do with it... It's like saying that your house is made out of bricks, so your entire house is shaped like a brick. (Sometimes it's true, but you get the point)
are you implying this universe is fake
he is implying we are in a simulation.
But if space is expanding wouldn't that mean that density would be declining as the volume increases and mass stays the same?
*more hydrogens made*
Space: Suck it Matt
Some one can please answer
@@ireallylikeclouds989 you are sayng that hydrogen are created with space?
@@educn6830 no that would defy the law of energy/mass conservation
@@MattFyrm thank you
What if the universe is so big that we cannot detect the curvature
Yes. That's exactly what I think.
I guess that's why the calculations were done from data obtained just after the big bang. The universe had just started expanding at that point of time.
That’s ... not how it works
Akash Raj - Yeah, it doesn't work like that at all, all matter from the big bang remains within our cosmic horizon or has past over our cosmic horizon over time. We say that all matter was concentrated to a single point only because we have calculated that BACKWARDS from space we observe today. There is no reason to believe space was not larger than a point at the moment of the big bang and that the big bang occurred everywhere with the space simply forever beyond our cosmic horizon.
@@callumscott953 Cant we see `just` after the big bang by looking 13.8 billion lightyears away? That's how we know about the cosmic background radiation and using trianulatiom we figured out the univers is flat (as stated in the video)
1:02 "There's only one shape space can be..."
Me: A potato!!?
Video: "...a giant hyperspace potato."
Me: HOLY CRAP I GOT IT RIGHT!!! *Subs*
But it's NOT a hyperspace potato...... :(
No one knows how big is space or what shape is space
Pandavap I love your profile pic |-/
Pandavap A POTATO!
So the milky way could be a french fry ?
*Space is just boneless*
Can i have uhhhhhh *boneless* space and uhhhh two liter of time? Said the universe to god
Joel The Process Embiid *S P A C E I S J U S T B O N E L E S S S P A G H E T I*
Joel The Process Embiid *Boundless
It's just a stupid meme he meant to say that
Space is just boneless matter
ok, just to avoid the confusion, flatness of space does NOT mean the space is like a 2 dimensional plane... the idea of flatness comes from the fact that we are measuring the angles of a triangle on the EDGE of the observable universe. In other words, all it says is that the triangle we are measuring is flat! Hence, all we can conclude is that universe is immensely huge (loosely speaking, sth like a sphere with infinite radius)! basically another confirmation that our universe is almost limitless... so please avoid using the term flatness over here. Instead, the more accurate thing to say is that the EDGE of observable universe is flat.
Reza Madankan Exactly.
Reza Madankan can you explain more because i can't understand
Reza Madankan which doesn't really mean anything, since the universe doesn't necessarily end at the edge of our observation. Who's to say we won't start getting light from far more matter out there, or even far less than we were expecting?
Flat means 2 D and anything with thickness or depth is not flat you stupid fucks. If you doubt me look up the word flat in a official Webster’s dictionary.
You stupid fucks are like the uneducated people in the dark ages who thought the earth was flat. In 700 years people will laugh at stupid mother fuckers who thought the universe was flat.
DO YOU UNDERSTAND YOU GOD DAM NEANDERTHAL?????
but what is a triangle? how do we know it's a triangle?
When even the universe is able to do cartwheel but you youre still unable to
At least you haven’t give yourself whiplash trying to do one. There’s no coming back when even a doctor in the ER has laughed at how you got hurt haha
I just want this to be seen cause I know no 1 will see my actual comment in a like a year
Have u seen those videos when they put a bowling bowl on a round sheet and smaller round objects if space is flat u cannot go under anything other rise u would go under space itself unless we think of it as a graph with 3d objects instead of 2d shapes the 3d objects can look as far as I want them to look
Wow u so stupid. The universe can’t cartwheel. Smh...
So he's not saying that space is flat as in 2D. He's saying it's flat as in it has no curves, still 3D but no curves
Doesn't have to be 3D, there could be more spacial dimensions out there that we just cannot even fathom, but regardless of the amount of dimensions, yes, flat as in no curves.
Chicken Of the Cave I thought matters interference with space created 3D
no this video says its flat like the earth but in reality a better explanation would be:
Space = game water physics
Niels Rasmussen
He's talking about curves with respect to the path of an undisrupted object.
It would actually be counter intuitive to think that an object could essentially accelerate without an external force being applied to it, so we are essentially taught this principle from a very early stage in physics studies.
The implications of space curvature are very interesting though. Imagine if you could permanently change an attribute of a finite region space so that the trajectory of objects passing through it is always predetermined.
It's flat on average, but local curves in space time exist everywhere there is gravity.
PBS Space Time, Physics Videos by Eugene Khutoryansky and minutephysics on the same day? Hell yeah.
Eugene
Feynstein 100 Eugene!!! Woop! And PBS is amazing, too. Love them all!
Feynstein 100 mathologer too
Flat earthers gonna like this video.
Yep
shaind god fucking damnit
Scientists and mathematicians say the geometry of the universe is flat, what are you, a science denier?
I love Daniel and Jorge Explain the Universe! Didn’t know I’d catch them here too
I love every second of this video. Beautifully written and described.
1:03 anyone else see the optical illusion?
Daniele Daniele was talking about the dots in the crossections tbh
The whole video is littered with illusions. You can't draw 3-dimensional objects on a 2d paper
I've seen both. :P
The lines are actually slightly curved. Since the screen is pixellated, you can see when the lines move up or down by one pixel.
Me
The Flat Earthers are going to love this video. They may ask how can we have a round earth in flat space? So if space is flat the earth must be too 😳 😂😂😂
Answer: Time is depicted on *CURVATURE, BOI!* in these lines of space’s expanse. SPACE is growing cuz particles are spreading. Since PARTICLES are spherical(perfect or not), the Earth. IS. ROUND. And so’s your head, get over it already!
Earth is obviously flat
Don't flat earthers believe that the earth is also a disk? Wouldn't the same reasoning fallacy apply for a disk as it would for a sphere? :P
I mean the Earth can be flat relitive to a higher dimension right? Nothing like the current flat earth model but *shrug*
I commented the exact same comment thinking "this is pretty funny, i bet no one said this" well i was wrong, so wrong.
"Cosmic hyper-potato." The best space name ever!
Wanna know what else is flat? That joke at the end
SHOOKETH!
And earth
@The main cause of warps in all of reality you just turned the frogs gay
And the earth
That a good joke, lol
Space is T H I C C
No, it's flat sadly :(
With that curvature ;)
Nah, it's flat
cuz flat is justice
You're fucking stupid. They just said it was flat. This comment would be funny if it was using double irony which only stretches the joke. I'm so fucking mad
Something can be "thick" and "flat" at the same time
FLAT IS JUSTICE
NON SEQUITUR IS PINEAPPLE
Goddammit Konata, you're like 30 y/o now, get over it already
Jose Perez In all the other universes Oppai is truth
Lolicon is my thing
Lel
Space is the shape of a Klein Bottle no doubt
Is the clein bottle the 4d shape in your profile pic
@@Q__22
It is, ruclips.net/video/JBB-1MenYiE/видео.html
You know you're a fuckin nerd when you're hyped to see a klein bottle comment
I'm just going to remain blissfully ignorant and pretend space is a hyperbolic potato. Neat video though.
60 Second Success Great Channel keep up the great work!
If space is potato shaped then it is not hyperbolic. One is positive curvature and the other is negative.
+Martin D A hyperbolic potato as in a Pringle
They're called books. Try it sometime.
60 Second Success Am I an unhyperbolic universe then? :D
"And yes the universe in constantly expanding"
"then what is it expanding into?"
"okay you just blew my mind"
-Ferb internal conversion aka a children's show (Phineas and Ferb)
you watch phineas and ferb too! man, we're busted
I love when Doof, was spelled Doof
Ferb is braining
It's expanding internally. There is no outside to expand into. It's not like a balloon filling up, it's like the surface of a balloon stretching. If you draw two dots on a balloon and inflate it, the distance between the dots increases, but it's an increase in the internal distance of the balloon surface, not an increase into something.
@@Merennulli I don't think my mind is capable of understanding how something can stretch and be finite and not have something outside of it
That explains Flat Stanley 😏😏😏
I have just left my Cosmology class on Shape of space & I was VERY confused. I immediately searched fpr this and I feel enlightened. Thank you for explaining in the best way possible ❤
Space is my city
city is my solar system
Universe is my country
Lucas Oliveira Saintrain potato is my life
galaxy is my continent
Space is my brain.
Does the universe had an end?
What is there at the end of the universe, another universe ?
hornetluca if at the end of this universe was another universe wouldn't it just be the same universe but longer
Octillerysnacker , mind blowing
If the universe is expanding faster than light, in the edge because of time dialation, time is "frozen". And no matter how fast you go you can't go faster than the edge, your time would slow down.
In the edge of the universe, it's like no time has passed since the big bang.
The end of space is unobservable -- light beyond the horizon will never reach our planet or our galaxy (since all matter is accelerating away from us)...
So for all intents and purposes, it doesn't matter whether there is an end. Kinda beautiful if you think about it.
hornetluca asking questions there might never be answers to
C'mon guys just admitted it
Space is a *Cat*
im an astronomer and the visualizations at 2:25 are actually really useful. thanks!
But, cosmological inflation is a widely accepted solution for the flatness problem. This video implies we have no idea at all why our universe might be flat, which seems plainly wrong.
Accepted as a plausible theory. I understand what you mean but it's hard to explain everything in 3 min. Also the "fuzzy part" before inflation is still difficult to model.
I guess you could say this video is
**puts on sunglasses**
flat out wrong
YYYYYYYEEEEEEEEAAAAAAAAAAAHHHH
I got too much sun today. Don't mind me.
Inflation is an as of yet unproven hypothesis. To claim that it is fact or the correct answer is putting the cart before the horse. There are also several other hypotheses that match what we know thus far and as such are equally likely. They are also exclusionary. We need more observation and experimentation before we can build a sound theory for the flatness or expansion problem.
because space is fake and the earth is flat
I thought Inflation explained why the universe was uniform in density. I don't think it explains why the shape of spacetime is flat. You could have a inflationary uniform-density universe with a bit more energy, and it would have positive curvature.
Everyone prepare for all the comments saying "If space is flat then Earth is flat too!!!"
Well, duh! If you think about Earth and the rest of the cosmos as the result of one big fart [the big bang] you'll see objective, irrefutable evidence that all celestial bodies our teachers have told us are round, in actuality, are flat! Why? Because "flatulence" has the word "flat" in it, obviously. It all makes sense, the damn government lied to us all!
Delta40 😂
If matter bends the Universe, then it can bend Earth too!
*Mind blown*
shut up rick!
Still better than "who's watching this in 2017"…
In addition, there is no way for us to know if we really viewed a significant portion of the universe, or we simply measured a small small area that therefore makes the universe seem flat, in a similar way that a triangle 100m wide would show the earth to be flat, while a triangle 2000km wide would prove it to be round.
That's why they say 'it seems to be', we may never know for sure. I mean we know that locally it's curved, also there is that Great Attractor drawing entire galaxies towards itself, so terms like local are on a whole different scale in spacetime. Who knows, maybe things work the other way around, and our universe "wants" to flatten, and that's the reason of the apparent perfect density, and not just some cosmic coincidence. Also, there is a chance that we got the wrong idea of something, did the wrong calculations based on that idea, and a lot of things we know might be simply wrong. Or maybe we are on the right track, but miss some crucial information. There is a whole slew of possibilities, luckily science is relentless.
I love that there is a Google + link in the decription 😀
3:05 *sarcastic laugh*
I read about the flat universe many times, but I didn't understand clearly before I watch this video.
2:30 My theory of why the universe has the exact amount of energy to be flat, it's just because if it were not that way then we would not be existing. Think about the conditions in which we would live, maybe some people do not think about it or pay attention but they have to remember how insignificant we are and the time we have living in this space-time.
AndyPiedram123 nope the shape of the universe should have no effect on life as far as I know
but every coincidence is highly unlikely, so to add on to you, i believe there is many universes with every possible combination of everything and we happened to live in this one
The inflationary theory allows for a region of flatness the size, or bigger than the observable universe and still be extremely curved as we zoom out into the whole size, wish according to eternal inflation might be 10^(10^30) times larger than the observable universe.
How would the curvature of space time be effected by an infinite universe?
In other words, the anthropic principle + many worlds interpretation.
My hypothesis is that the net energy in the universe is zero. We started with nothing, but nothingness can split into positive and negative energy (like quantum foam). No matter how much you split zero into positive and negative matter/energy, we still get a flat universe.
We would just be occupying the portions of space in which positive matter just happened to never cancel out with the negative.
Antimatter could easily be repelled by gravity, dispersing into deep space.
The confusion comes from the fact that all diagrams of space time are originally 2d, and when manipulated 3d. That’s because space is entirely 3d when unaffected and 4d when manipulated by mass and dark matter, and you can’t really show people 4d space. It’s literally impossible to comprehend with traditional brains.
A flat universe implies an expanding universe with a decreasing velocity approaching zero. However, what we've seen instead is expanding universe with an increasing velocity due to dark energy. So unless matter is being created out of nothing somewhere, mass-density will continue to drop and become more and more negative.
How are astronomers and physicists reconciling "flat" mass-density versus accelerating expansion? it seems to be a contradiction, as there is an ever increasing volume without a corresponding increase in matter (mass).
The universe could change shape
Dark energy and regular matter do not interact in normal ways. So it might be possible for Dark energy to cause the Universe to expand while having the universe retain it's shape. Also, the shape of our universe depends on the amount of matter, or mass and energy, and as far was we know, dark energy has no mass, and exerts no "normal" energy on regular matter. Note. The expansion of the Universe is a weird and not normal interaction of matter and dark energy. Please correct me if I got anything wrong! I'd love to continue this conversation!
Here are some diagrams that might explain better:
www.schoolphysics.co.uk/age16-19/Astrophysics/text/Universe_flat_closed_or_open/index.html and
upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Universe.svg/2000px-Universe.svg.png
minutephysics says the universe is flat due to mass-density (omega) estimates being close to 1. But that is not what we observe when we measure universal expansion. What we see is a positive acceleration, which corresponds to an open universe:
phys.org/news/2015-04-mysterious-dark-energy-universe-expansion.html
So I don't understand if there are completing claims, or if minutephysics is just working with old data that was used before the discovery of an accelerating expanding universe and dark energy?
The scenarios you mention, and diagrams raven lord provided, assume no dark energy because they're older than its discovery in 1998.
Here's an article and diagram about that scenario, which you can see was published in 1995.
archive.ncsa.illinois.edu/Cyberia/Cosmos/CosmosFate.html
Lol when y'all gonna learn that we know nothing about space and everything we do "know" about space are just educated guesses
everything is designed perfectly, the more I know the more I get that this universe is not just a coincidence, there is a smart design and a designer beyond our comprehension.
Actually, the theory of inflation perfectly explains why we live in a flat universe.
Vark321 keyword: "theory"
Actually it is the hypothesis of inflation. There are many competing hypotheses about the early universe and how to explain what we see and why. We need more evidence before any of these can be a testable and predictable theory. When speaking in science it is only correct to use the scientific definitions for theory and hypothesis instead of the colloquial ones.
Andrea Teal Not really. Theory in science means it has significant backing based on observation and repeated experimentation. Scientific laws are theories which have undergone so much experimentation under so many different circumstances that they are now widely held to be true, and would require extraordinary evidence to disprove.
+AvalancheofNeed Sorry but that is not the definition of a scientific law. Scientific laws are expressed as mathematical formulas that describe how a phenomenon behaves. They do not attempt to explain any mechanism, just what is observed. They basically only state "this is happening and it can be described with this formula". For example, the Law of Gravity is not the same thing as the Theory of Gravity.
en.wikipedia.org/wiki/Scientific_law
In astrophysics inflation is considered a theory: en.wikipedia.org/wiki/Inflation_(cosmology)
For years, I've struggled to understand what physicists really mean when they say space is flat. I get it now and it's thanks to this video.
Suggestion: What if Earth has TWO Moons?
Kabloosh But it has.
only 1
Humans would probably not exist. We are an amazing cosmic miracle, and very small changes to our solar system could mean no life on earth. Life is freaking nuts, dont waste it i guess lol
Derian Parsons It's probably losing and gaining moons all the time
i read somewhere that earth has 2 moons, 1 is the moon that we already know, the other one is some kind of meteorite or something orbitting earth. I forget what the effects of the second moon does tho, look it up
What if, extra curvature in space causes anti matter to become transformed into an undetectable for of matter, stopping regular matter from becoming annihilated. Causing space to constantly balance itself toward a flat state while explaining both dark matter and why there exists more matter than anti matter.
I must be right, I'm some random guy on the internet giving an off the cuff guess.
en.wikipedia.org/wiki/Baryon_asymmetry#Regions_of_the_universe_where_antimatter_dominates
en.wikipedia.org/wiki/Annihilation
Jokes aside about being a random Joe, it is indeed very unlikely as we probably should have already detected such disturbances. Take in account that curvature of space does not make two particles uncollidable, otherwise it would be a very radical property of space that remains undiscovered and would require a theory compatible with current knowledge, plus any missing positive evidence for whatever such theory predicts.
Furthermore, you should already know that in it's verbatim sense, "undetectable" is a concept science is not anyhow interested, if that's what you meant.
Me too. Doesn’t mean we couldn’t have brought up something new to a real table of study!
So would there be an undetectable anti matter mirror universe? I kinda like that idea. Seems legit.
Space is like a great big ball of wibbly wobbly timey-whimey... Sstuff
Eeeeeeeeeeeeeeeeeeee
Doctor whomst'dlyaint
I get the reference. The OG rick and morty
@@nathanbrawley7256 yes that's the one
Nathan Brawley well the OG Rick and Morty was Back To The Future.
this is pretty much the ‘fine tuning argument’ (fyi. hydrogen atoms per cubic meter are not the only fine-tuned values).
You are absolutely right, that we can’t explain this in a testable way for now.
I would like to highlight something very important tho: it’s not the universe that is fine-tuned for us, but rather we adapted to an already existing universe. Which obviously raises the idea that our universe might not be the only one.
Well being a follower of the anthropic principle, the reason we live in a specific universe is because we... well we NEED to be. Check the anthropic principal on youtube or wikipedia for a better explanation
I find it interesting too. I'd love to use it against creationists.
@@pranavarvind4281 I use it against atheists
Nestrislia Crystal how does the Anthropic Principle go against atheists? If anything, it totally removes the necessity for a god to exist for us to exist, and then we can apply Occam’s Razor, meaning that it’s more probable that the universe just came out of nothing than an arbitrary god coming out of nothing and then creating the universe.
imagine if we actually live in a cool cosmic hyper-potato thoughhh🤩
It actually could be. But then the cosmic hyper-potato would have to be so large that we cannot tell
No, this is Technoblade's Potato Deity
Me: I would like to order space fries.
Could we also find out the shape of space in some places like this: if we know the speed things like the sun, earth and moon orbit, then we can test on different shapes of fabric, have some balls on the fabric just scaled down and scale down the speed too and test all the shapes and see if they match? Flat fabric is often used to demonstrate gravity.
you can make religion out of this!
no don't
the sun iz a deadly lazer
@@areg7182 U FRICKING MISSPELLED A 2 LETTER WORD!!!111!!
@@Ratmania7777chill it's a meme
*noooooo*
1:00 for the Hermann grid illusion anyone?
5 is the only Fibonacci Number greater than Zero that is the same as the number of the term
But centimetres are a pretty arbitrary unit. Measure it in inches cubed or metres cubed and the number is no longer 5.
@@jeffvader811 you're thinking of the spiral. If you just count along(1, 1, 2, 3, 5...) Then this is true.
wow very super
@@dabest8147
I think the original comment I replied to was deleted. For context it went something along the lines of "there are 5 atoms of hydrogen per cm^3 in space" and they tried to correlate that with the Fibonacci sequence :)
There is something out there that is way beyond what we can comprehend. Like this universe is just a tiny part of something that is so much bigger and only when we figure out what that is can we start to explain black holes and space properly. It’s the ultimate mystery
Coincidence 😅. Since when did we start using the word coincidence for perfect balance?
because perfect balance would be a coincidence?
BakedBeans that doesnt seem cleverly. What a coincidence (!) That makes happen all life. And in this life only human can think on everything. There must be something we dont want to understand. We have to make an effort to understand the Real.
@@seyyidhansaroglu We are not basing off the coincidence as a 'mere' coincidence. We are indeed trying to find out the reason for this coincidence, although studies in that regard are still pretty illusive. Hence, we term it as coincidence to satisfy the momentary curiosity of ours.
don't tell me ur a flat universer
I like the old MP, when you used to draw your explanation. You've changed. D:
/sarcasm
This explanation was way easier to understand than most. Thank you!
For the people saying that it is not a coincidence it is not flat
I want you to realize that everything had to go perfect for the first bacteria to be alive and it to not die by tomorrow
If something is flat then is flat people are not asking why are elemental particles round and why do we still call something flat even do it has a lot of spheres in it
It can be space-time is a weird thing we live in yet it is still able to be understand if you people stop using assumption and anologys because of you thinking it's "normal" nothing is normal and it dosent make sense so shut up and accept that something exists even do it dosent go to your opinion
I don't know of anything that causes negative curvature of spacetime though. Except for white holes, which don't exist, right?
We observe an effect that we call Gravitational lensing from relatively dense patches of the universe; this could be called convex lensing. It should be possible to have concave lensing with a torus of matter.
+Reckless Roges Hey I never thought of that. I read in Michio Kaku's Physics of the Impossible that negative mass does actually exist. Not sure about the validity of that but in principle, the negative mass should be able to produce a negative curvature on spacetime.
Maybe Dark Energy could cause negative curvature?
Indeed, vacuum energy causes negative curvature.
Vacuum energy is the energy of empty space. It is the most likely candidate for dark energy, though we don’t really know. However, I posted without thinking in saying that vacuum energy would cause negative curvature. I was momentarily confused by Henry’s video which gives a misleading picture. In fact, the kind of curvature he is talking about in the latter part of the video - the global curvature of space - doesn’t actually have much to do with energy density contrary to what he says. It is an intrinsic property of space time.
Basically, in cosmology we have an equation which governs the evolution of the universe (Friedman equation, which is actually an applied version of the equations of general relativity). On one side we have the properties of space time: the rate of expansion and the curvature of space, and on the other there is the energy density of matter. If the curvature part is zero, corresponding to a flat universe, then the rate of expansion is directly proportional to energy density. Cosmologists like to use this case as a reference and so they define a quantity called critical density which is the kind of density that evolves proportionally to the expansion rate. In other words, it is how the density would evolve in a flat universe. So the point is not that there is some magical number for the energy density which makes the universe flat, but rather there is some relationship between how density evolves with respect to the expansion rate that is different in a flat universe compared to a curved universe.
This is gonna be a long one so strap in
One of two options are possible about the universes origin.
1: We are the only universe
If this is true, we have won the cosmic lottery by being alive, just the rules of the universe being how they are because of all things that could happen, our world happened. If this is true, we must live our lives to the fullest
2: We live in an infintly sized multiverse
This makes sense as A; In the CBR of space, we can see a cold spot that would make sense if another universe bumped with us; and B; Universe's can be made in pairs. If string theory is right, then our universe is just one huge string and during the big bang we collided with another universe-string. This makes even more sense as the equation "Energy= Mass (of object)× [300,000,000 mps²]²," and antimatter collisions being 100% efficient mass-energy converters would make it so that if we collided with an antimatter universe-string and it wasn't perfect, we would have our
Over underrated
Excellent representation. The term flat throws me off. I’m a layman so for me flat basically means two dimensional plane with x y coordinates. But when physicists say flat they mean essentially x,y,z coordinates on an axis. Flat planes intersecting like a cosmic grid naturally square until energy creates matter which then bends space creating gravity or rather the ability to experience gravity. The bending and morphing of space creates events that can be described as traveling in the 4th dimension which is time. Got it.
Flat Earther: See? Space is flat. So is our Earth!
Raj Srikar Technically it would be, but it’s not.
Flat in 4d sense is different than in 3d sense :)
The earth is flat... In 4-dimensional terms :)
3D
Underrated
Could we be in a simulation then ?
nuke4sen yes
It's deeper than that. We are a thought.
nuke4sen could we, yes, but there is no reason to assume that we are
Anticonny It does matter i think..
i'd like to know
We cannot be in a simulation, because that doesn't explain consciousness. Consciousness is no 'illusion' of a physical reality... Perhaps astonishingly - because we all simply assume it's real - there is no objective scientific evidence for a physical reality. Physical reality is an illusion of consciousness. www.scottowen.org/topic/luciddream
THIS CHANNEL HAS SO MANY PUNS IN EVERY VIDEO I LOVE IT
It's like a ball of jello, grape flavor, we're bacteria
I'm a fungi.
Wait a minute…
**Jeopardy theme plays**
What?
exactly,
Wait if I remember correctly, according to Einstein's general relativity the space is flat but it curves on itself because of the gravity it exerts on itself, right? So the best way to describe the universe is actually the Pac-Man way...
dang girl, your space has a nice curvature ;) lol!
hahahah that's funny, someone else said I have a pancake butt so I made an entire video dedicated to them. I'm starting to wonder if mine really is flat though.
Benjamin Weissman DAMN SHOTS FIRED.
lol Benjamin, I was hoping you'd say that your original comment wasn't actually directed at me...butt knowing that you spent your time to watch one of my videos just to see what my backside looks like has given me a good chuckle.
Jackal Unleashed you said butt lol
all light bends towards you girlll you the spotlight ;)
I was looking for something a little more serious, but thank you all the same.
well, this is named "minutephysics" for a reason
I miss the stick figures
But do the stick figures miss you?
They might
is your aim getting better?
*Oh, entropy!*
here comes the villain of everything
and that, my liege, is how we know the earth to be banana shaped
This Science is amazing! Tell me again how sheep's bladders may be employed to prevent earthquakes.
You are like Sir Einstein you explain every thing simply . I hope i had a physics teacher like you. Thankyou
With flat space, you could have a universe with zero net energy.
Ah damn now how am I gonna power my nets.
can i get some sources for this
want to do some further reading on the matter
thanks :)
“It’s a coincidence!”
*smiles knowingly*
*pulls out bible*
animation here is godly
*looks into sky*
I SEE NO CURVE
If it is flat then which way is up?
OmniBot I was thinking this... but I have nooo idea
I dont know if this is exactly what you asked ...
but it's space, how would you know where the surface is
OmniBot There is no ABSOLUTE “up” or “down” or “sideways”. Everything is relative.
A 2D grid is flat. Which way is up on the grid? Our 3D space is flat.
The universe is flat, flat Earth proven
Grass is green, so all green things are grass?
The universe is a cube
CHIP The universe is mostly a sphere them a cube
More a rectangle.
Bunny YA! CHECK MATE ATHIE- shit wrong reply.
fun fact, in space with negative curvature, there is a _maximum size_ of triangle.
for a given constant negative curvature, there is some area for which it is impossible to create a triangle with greater area than that
I’m a flat universer
Will know later...
after we die
For me, not 100% sure, but I think that when you doe, you simply die.
We'll*
No, this is a Science related channel, please don't spread ignorance of that level!
MLG 360 NOSCOPE no there is nothing DARKNESS DARKNESS AHHHHH
Vinyas Singh Ignorance, eh? Do we have evidence that there isn't an afterlife?
0:06
Why are there cats in the box
It's a joke in reference to schrödinger's cat
What
I don't think I really understand. So "flat universe" in this case does not refer to the dimensions we perceive the universe to have, but rather to how the space is distorted? Like, "flat" means that space is by default not distorted (though gravity does distort it and since gravity has no range as such everything is in some way bent and curved and rippled). Is that correct?
Yes. So if you were to remove all mass from a flat universe, parallel lines would meet only at infinity.
But give an example of negativy curved space!
Your ass.
Quickburger9000 Deal with it. Take for example the hyperbolic plane H^2:={(x,y) in R^2 | y>0 } with the metric g_ij(x,y)=1/y^2. This gives you a 2 dimensional riemannian manifold that has constant curvature of -1
Quickburger9000 Deal with it. You could also take the pioncare-disc as an example but as far as i know there is an isometric isomorphism between those two and thus they are pretty much the same
Rekt
Don't worry friend, I understand everything you said. - Fellow Math Major :))
Its the "spacetime", though, that is curved, not the "space" without the "time".
Bro u said it . Space-time bend near mass . This ppl don't even know Einsteins theory
I know why our universe has the perfect amout of mass to make a nice space time grid. Because it's a designed and God made universe.
Retarded comment. Nice space time grid was created by humans. But it looks like this comment is a joke, so I'm just hoping.
best explanation so far!
Great now we have to deal with “Round sapcers” claiming that the universe is actually round
Sigh....
2:14 It’s almost like some cosmic being is monkeying with the universe?
Galactus
*cough* we live in a simulation *cough*
o O 0 maybe
What if we are a simulation inside of a simulation which is in part a simulation inside of our simulation?
o O 0 it's more likely than not
Kado: The Right Answer is one hell of an anime about this topic.
o O 0 We can't know if we live in the "real" reality or not and we'll never be able to tell what the "real" Reality truly is. It could all be a simulation inside a simulation inside a.... and so on.
I honestly believe that there is no way that everything that exist is just perfect for no reason or it’s just coincidental, intelligent design is clear and litterally stares us in the eyes taking up all space we can see and yelling infinitely “i am here!” Like horton and The Who’s.