Where Is The Center of The Universe? 

Best comment lol, Euclid would be proud.

(0,0,0,0) actually

@@johnretherford592 Or perhaps use a quaternion with a direction that always points at the big bang :)

We are 0,0,0,0,00|0000,00:00:00 Earth is the center of the universe. The exact center. Or was before the sun and planets formed and it started to wobble around its orbit .

@@Unkl_Bob i can not tell if you are joking, but no, we are not at the center of our universe, and the Earth formed at the same time as the other planets.

When you use the word "universe" what exactly do you mean by it or what do you seek to convey when you use the term "universe"? Why not just own up and admit that you have absolutely no idea whatsoever what you mean by universe or what you seek to convey when you use the term?

@@vhawk1951kl Quantum weirdness? In my version of the universe, he never used the word “universe”. Your observation seems to have produced a different result!

@@AllanTingey exactly what I thought, I read it like 3 times, thinking how am I missing it.. the word isn't even there, & you just got some belter blabbing on about something that he's imagined.. maybe the Klingons kidnapped him & stole his keyboard.. about as random as his comment aye.

LOL, yea! I was just commenting above how it wasn't that long ago that it a singularity that went bang. Now might not have been a bang at all. I feel to cheated! LOL

There's those of us who understands that we can't remotely understand our immesurable universe, and then there are those who pretend that they do. Quite arrogant if you ask me.

You actually understand something because of this? What? It's 20 minutes of tripe as far as I can tell. I WOULD BE DELIGHTED TO LEARN SOMETHING FROM YOU. But really doubt that is going to happen.

​​​​@@kurtisengle6256so from my understanding of it, imagine the entire universe as the surface of a balloon not the inside, just the surface of the balloon that you can see and touch. Before air is pumped into the balloon it is the size of a single dot. Everything in existence is at that very centerpoint. Now imagine there is a little blue circle drawn on the surface of the balloon. To keep it simple, that will be the Milky Way where Earth is located. Now let's say there is also a green circle located nearby. Let's say that is some other galaxy. If you pump air into the balloon, the circle will slowly start to expand as the balloon is stretched out. And at the same time the two will grow farther apart as well. That is a VERY basic understanding of the universe expanding. Just replace the idea of the circles being two galaxies with observable universes. I understood that for a while, but it wasn't until this video until it clicked that the air filling up the balloon would be the dimension of time. The more time you put into the balloon the more expands, and if you let the time leak out, run the clock in reverse, eventually everything will shrink back down to that one point. Normally thinking of it as the universe being a balloon you would intuitively want to say well wherever the center of the balloon would be, that must be the center. But you got to view it as the outside layer of the balloon being space and the air inside the balloon as time. That's what made it click for me

Can't be sure of anything scientific proofs don't exist

I hate when anyone says anything they say or think about the universe is fact. "I think..." Or "I'm not sure but..." Are required. It's simply unintelligent to think you know anything about the universe for certain.

This open and frank humility is an absolute for anyone honest about trying to understand just about anything. And as Kyle and Dylan point out, the scientific method isn't about reaching certainty or proof so much as rooting out bad theories. It's our certainty-craving minds that want the results of every new study to be definitive or True. This is why science is so important--it is the best system discovered so far for pushing back on our primal need to feel like we understand what we experience, and our inherent bias toward our own subjective interpretation of that experience.

@@kendrickmcelfish2805 You know, I didn't even make the connection to the CMBR until you said it, but, yes, that explains it completely!

This is probably the first time that i see someone commenting that they clearly understood the topic of the video

,, jk comments :: feel jealous,, kinda, oim noteven sure what I understood leastetest,, yet love th' ride,, as owlwoyss ...

No matter where you go your in the center of the universe.

@Shon Mardani 🤡

How much energy would it take to warp how much space

That’s fcked up

Ahh you are a universe in its own right ready for your own big bang

@@69TheGG 🤣

@@osmosisjones4912 The energy subtracted from chromosomes you're missing.

In principle yes. But you could never do that experiment, because the expansion of the Universe is faster than the speed of light. It would be like trying to send two ships into two different directions to have them meet on the other side of the planet, while the planet is expanding much faster than the ships could ever travel.

There is another Spacetime episode involving this, the one about a spaceship colliding with itself by going fast enough to length contract a closed universe to a size smaller than the spaceship. That's the premise anyways - the episode goes into if this would actually happen.

@@AliothAncalagon if thats the truth then we would not see the stars or any lights from the space

@@sudarshanchatterjee6911 From those spaces there is indeed no light reaching us. Thats why the observable universe has the boundaries that we see. Its the observable horizon of objects that were close enough to us, that the expansion rate which made them move away from us did not surpass the speed of light at the time their light started traveling towards us. In a universe that is overall expanding, two points will move away from each other with a speed that is mostly proportionate to their distance. For close objects thats not much. For further objects this becomes more relevant. And for very far objects this becomes faster than the speed of light. Thats why the latter will eventually become so fast, that their light can no longer reach us. In the very far future this will by the way be the destiny for every other galaxy cluster. Eventually every single other galaxy cluster will be so far away, that we will no longer be able to see it.

@@AliothAncalagon that is while u are assuming the size of the universe is infinite. Your assumption would have been correct if there were no gravitational force. May be I'm wrong

Would you say you are well uni-'versed' or are you a multi-'versed' type of person? 😎

@@keenfire8151 I bow to your greatness.

Well, it's "way beyond you" because - as stated - you've *only taken a half dozen classes on Astronomy"!*

@@jondunmore4268 Just the astronomy courses, and they were mostly beyond the intro ones. Also doesn't include the mathematics courses and individual research over the decades. Take the compliment without being condescending

@@OleOlson -- Take the joke without being snowflakey

I assume that as time is 1 dimensional it is simply line like, however that is a very good question.

Those things shouldn't be dependant. A flat universe would imply infinite, or we would have some boundary problems at the edges. Parabolic should be able to expand indefinitely, as it would never meet itself. A 3-sphere geometry could also expand indefinitely, as it is like asking "what is the maximum size of a circle?" -any size you want. All of these shapes could collapse. That depends on the balance between "dark energy" and matter. All of these geometries could go back the way they came from. Or expand indefinitely. There is also a 4th spatial geometry- a torus. But that has some separate issues. But largely: time is a mystery. Nobody knows what the h*!! it is. It's not just another dimension. That is why it's represented with a Zero in the field equations for G.R.- it's special. ...So... Your answer is probably not. These things should be independent. But we know very little about anything.

According to the No big Crunch theorem for flat or open topologies in the general domain of the Einstein field equations, yes. The theorem from Inhomogenous and Anistropic cosmology: Matthew Kleban and Leonardo Senatore JCAP10(2016)022 says in explicit technical jargon. There cannot exist a non-singular spacelike hypersurface with maximum volume: given any time slice, there is another with larger spatial volume. Furthermore, in an initially expanding universe there must be at least one expanding region on every timeslice, and if Λ > 0 the expansion rate in that region is bounded from below by that of de Sitter spacetime in the flat slicing. More generally it implies for any arbitrary initial conditions within its valid domain it can be shown by a proof through contradiction that not only must any initially expanding universe expand forever, (while any initially contracting universe must conversely contract forever) but within any possible slice of time the volume of that space will always be larger(or smaller) than the preceding time slice. This theorem effectively shows that within the domain where the proof is defined that for any universe which isn't perfectly homogenous and isotropic at all possible scales within spacetime any inhomogeneities and or anisotropies within an initially expanding universe it will never be possible for the off-diagonal terms of the metric tensor to ever balance out ensuring that these off diagonal nonlinear terms will always amplify any asymmetries outside the domain of the Friedmann-Lemaître-Robertson-Walker metric. Interestingly from this property of asymmetries within an expanding universe ensuring the volume within any time slice always increases it appears that this condition is mathematically equivalent to the second law of thermodynamics that entropy always increases if there is a connection between the geometry of spacetime and entropy which according to black hole thermodynamics there is. Technically even the Friedman solutions obeys this property in the case where the universe is invariant in time (i.e. the trivial solution) suggesting this falsifies the existence of the cosmological principal assumption within the set of all physically valid solutions to the Einstein field equations within any flat or open 3+1 dimensional spacetime because all other solutions must violate the No big Crunch theorem which can be shown to be mathematically identical to the second law of thermodynamics if space has an associated entropy. The same theorem implications though however don't rule out the possibility that some sufficiently small slice of spacetime within an expanding closed general potentially inhomogeneous and anisotropic universe doesn't expand fast enough to prevent collapse however as the nonlinear domain of the metric tensor appears to be naturally predisposed to breaking spatial symmetries and amplifying those symmetry breaks to larger scales. However this is already stretching the limits of the proof so it can't be rigorously defined in a theorem currently. TLDR yes any flat or open universe the rate of expansion can never change sign or be zero. The converse a closed Universe is not necessarily true you can potentially get regions that expand fast enough to overcome the slowing of expansion elsewhere.

There is no "spatial shape" and "temporal shape", there is only the overal shape of the 4D spacetime. When we ignored time that was for the purposes of visualization, since we need to remove 2 dimensions from 4D spacetime just to be able to visualize it on a screen.

Yes @PBSSpaceTime please answer this in the comment portion of the next video

Some days I feel like I understand and some days what Matt says goes right over my head. Watch the video twice or 3 times and see if you get more out of it, idk works for me. Godspeed

What if we're in only the most recent big bang? Just as galaxies crash into each other and black holes grow and swallow everything. What if two black holes grow so large and come together, boom,big bang. A cycle that repeats every 100 ish billion years give or take. Just a thought for when you can't sleep ... sorry. ; 》

@@notme2day Yes, I have those thoughts about the universe being in a cycle of some kind. Probably because it is a more pleasant thought than one and done. I still can't understand the center of the universe arguments. Not simple enough for me. I may have to watch it a few more times as Ryan suggested.

@@notme2day and then the astrophysicist says the universe is expanding at an increasing rate. Unless our observable universe will merge with another expanding universe, this cycle is not possible

​@@_Wai_Wai_ Conformal cyclical cosmology makes it possible for an endless expansion to result in a new universe, though the evidence seems to lean into any acceleration of the universe's expansion slowing down(w ~= -0.99) even ignoring the question of whether that acceleration's real at all(a few structures have been found that are far too large for the cosmological principle as currently understood).

Or you can just quietly point at any direction at all...

I'm pretty sure you could answer this yourself, Fraser.

13:48 ... "It’s one thing to think that you’re the center of the universe - it’s another thing entirely to have this confirmed by an ancient prophecy." (i.e. Total Perspective Vortex, s. Douglas Adams ;)

Okay, So, it does mean if I call myself Center of Reality(ಠ ͜ʖ ಠ), it is not wrong as in the past of universe, all Matter and energy was together in singular place. I know it just like simpson, I am the choose one (ಥ‿ಥ)¯\_( ͠° ͟ʖ °͠ )_/¯乁( ⁰͡ Ĺ̯ ⁰͡ ) ㄏ (ಠ_ʖಠ)🤣🤣🤣

I love it when major RU-vid content creators interact with each other.

Yeah, i know basically nothing about those 2 things and always confused me, so id like to see an episode

Isn't the imaginary number line just a way to map out things in 2 dimensions? You could do away with the imaginary numbers and just add a second axis of numbers.

It's worth making the distinction that the imaginary number line is fundamental to modelling and understanding the universe, not a real physical thing that is integral to how the universe actually works.

@@rantingrodent416 - I just asked this, but I will ask you directly since you might know. Isn't the imaginary number line just like a 2nd axis, giving 2 dimensions to numbers? You could accomplish the same thing with another axis of numbers.

@@rantingrodent416 isn't there an imaginary number in the Schrodinger equation tho? Or does that count as modeling

OZZY OSBOURNE - Center of Eternity ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-USQGrE8JtY0.html

Read the Ra Material, my friend. It is free.

The same thing applies to every person so you are not special.

Pakistan is the centre of the universe according to most people .

Of course you are the center of the Universe... in your Mind.

@@jessepollard7132 Every person is special, as special as everyone else - except identical twins. Another exception is when you're just plain stupid - rocks, trees etc are more similar to each other than 2 smart people.

Isn't the rule it's never aliens going against the Kepergigan principal

And I love you brother 🥰

Love these comments both positively reinforcing the content quality and pointing out its effects, leading to an elevated state of happiness for its readers

@@osmosisjones4912 The rule is "It's never aliens until it is aliens", so no it doesn't go against the Copernican principle. It just means we have a tendency to jump to the conclusion of aliens but historically when the evidence is properly examined it has been something much more mundane. If we get compelling evidence of aliens anyone scientifically minded should believe it is aliens.

@@L0kias1 THE NOTHING

I think I heard Alan Guth say that in eternal inflation, the minimum size of our pocket universe is something like 10^23 times bigger than the observable universe. But the theory gives no upper bounds on this, so it could be much larger

No way to test this by the way, at least not today.. this is theory at best and you'd have to get fancy with physics and math..

Because this channel diggs deeper than the other physics channels on YT

*took you back Things are brought to you

Just curious but who is Gabe?

@@testimonyoftime he was the previous host of the show 😊 Seemed like a really great guy

@ Kassie Lee- It is very possible the universe has no idea what math is.... or even cares. It was nice of humanity to organize it though.

:) good

I have an idea about that but I'm not entirely sure. Imagine a spherical showerhead, it shoots water in all directions. Imagine there's no gravity, so the water keeps going in a straight line. Imagine the holes on the showerhead are very small, very many and very densely packed. If you turned on the shower, you'd see a spherical fog growing outwards that's densest in the middle and gradually gets less dense as it moves outwards. The (observable) universe is not like that, it's homogeneous, you can't point to a direction and say the universe is less dense over there or more dense over there.

The problem with this is that the universe is not expanding from a single point. That would be traceable (to a degree) It is expanding equally in all directions. Everything is expanding away from us in all directions, and at some other random part of the universe everything is expanding away from that point. The geometry of a big ball does not hold up there, unless you are assuming that there is an "edge" that will eventually be reached, or that the ball is infinite (then is it really a ball at all?). I think the theory with the "cloud like shape with a center" in this video is the closest version of the universe to what you are referring to.

Theoretically Black Holes do explode at the end of their life. We've been looking for evidence of this, albeit unsuccessfully so far. Although not unsurprising as Black Holes can live for quite some time.

Here’s your answer. Everything is moving away from us. The further it is, the faster it is moving. Do you think we are at the centre of the universe? If so, then there shouldn’t be anything here since everything would have expanded away from this point. Ergo, it’s obvious there’s no centre since you can’t place that centre here nor anywhere. Capiche?

Well, I do know that I am the center of my observable universe. ;-)

That's mentioned in the game Pneuma 😀

Lol sure. Now I feel like a joystick.

Nope. The reason we feel like we are in the center of the universe is because it wraps around, not due to observer relativity.

I've seen animation that does that, it's a neat effect.

You have a great name!

@@notme2day Thank you., whoever you are today. Not a bad name yourself.

Wouldn't exactly say the light is magnified, rather it's blurred and needs to be focused.

Iirc light always travels parallel to space (hard to make sense of parallel to 3d space but idk), which is what causes gravitational lensing(in the local spatial deformation of massive bodies the parallel path is completely messed up), and since space seems to expand at the same accelerating rate everywhere, the perceived size would not be affected by it because space expands but the parallel path never changes it shape (except on gravitational lensing where the local space is very distorted from the average and so is the parallel path because of that)

Yes, if you take two galaxies of the same diameter that have the right distance from us, the older further away one looks larger than the newer, closer one

I think kind of? Clusters that were x megaparsecs apart 380,000 years after the Big Bang are now about 1100x parsecs apart, as is the light emitted by them. But the radiation has also been stretched 1100 times (from near UV to microwave), so you don't actually get any better resolution. You get the same amount of detail as if the universe were static, I think.

Yes, good intuition! Before getting to your question some context will be helpful: In cosmology there are multiple ways to define the distance to an object - as you might expect it takes some nuance to talk about distance when the universe itself is expanding with time and you deal with things like speed of light delay. The most natural and intuitive measure of distance is called the comoving distance, which you can imagine as the distance you would measure to an object if you were to stop time and extend a really long tape measure to the object. However there are other distance measures that are useful when dealing with certain questions. The concept you've described here - that objects appear to get larger as you look farther away in the universe - is made rigorous by the "angular diameter distance" measure. The wikipedia page describing it is sparse and technical, but take a look at the diagram labeled "Comparison of Distance Measures 0 > z > 10,000" en.wikipedia.org/wiki/Distance_measures_(cosmology) What you should see is that, around a redshift of 1.5, this distance measure reaches a maximum and then turns around. This corresponds to the point at which objects of a particular size start to appear larger in the night sky the farther away they are. In our current best model for the universe (lambda-CDM) this point occurs at very roughly 9 billion years ago and 13 billion light years away (edit: comoving distance)

@[Twitch Streaming Channel] Q A combination of mothballs, dry toothpaste and pretty much anything from under the kitchen sink will get you there. Can't vouch for your lifespan tho.

i am just here to be together with other people slowly going crazy

Astrophysics can be a little dazzling because it's just a little bit out there. But its explanations are mostly ethereal. What really is hard to crack is solid state physics. The pressures can be immense!

@@hardopinions hehe

I think it hurts everyone's brain.

@@VenturiLife I mean, everyone has their own strengths and weaknesses. Clearly Matt knows what he's talking about and comprehends this stuff without his brain going mush. On the flip side, he may not know how to design an x-ray flat panel detector like I do so... 🤷‍♂️

Actually, I think that this is certainly an interesting exercise for the brain, but in 100 years' time much of this information could be irrelevant. After all, we're talking about a possible model of the universe here, and, as a practical person, I find that there are too many presuppositions and rough estimates in our contemplation when we're trying to prove that this model is indeed practical. I'm not talking about truth here, because that's a philosophical question, I'm talking about a practical, understandable, simple model of our universe, or a part of our universe. Should we make it that complicated, may I ask? The fall of an apple can be explained with Newton's and Einstein's theory alike, but Newton's theory is much simpler and elegant, although less punctual in a greater scale. The theory of relativity was created to explain phenomena taking place at bigger speeds, in the larger scale of the iuniverse. Still, we don't use it to explain the fall of an apple here on our Earth. We think that the theory of relativity is a more general rule in our universe than Newton's laws, but isn't it possible that it has just as limited validity as they have? There might be large areas in spacetime, in the universe (and beyond), in which the laws of relativity lose their relevance. Einstein's model is just a model, too, and who knows if this model is applicable 10 billion light years away, or indeed if it WAS applicable when the light rays that we can see now started from a distant star or galaxy. Or isn't it possible that in other areas of spacetime there ae other local rules that are also special cases of the relativity theory? In any case, I don't believe that we can explain the whole universe with one unified theory (string theory, multiple universes, etc.) It would either be too difficult and unpractical to work with, or it would be impossible to create because it would have boundaries. We should perhaps look for more locally valid, simpler explanations to the observable phenomena. I'm sure, the universe locally can be explained with simple, elegant theories no matter where we are in spacetime. But is it established for sure that the speed of light, for example, is, and has always been the same in each part of the universe? Scientists strive to explain everything with one, final, unified theory. I don't think that one such necessarily exists, and even if it were possible to make up such a unified theory, it will not be able to explain things happening beyond event horizons and in singularities. As these are parts of the reality, too, the unified theory would have a pretty limited validity! So it might be more practical to establish laws of physics of more limited scope for more concrete, more palpable areas of our universe. That way, we might get nearer to the big picture.

It finally got released too. I can't wait to explore other geometries and topologies 😊

As a videogame it's a bit rubbish though. Constantly-talking NPCs and busywork that happens in a hyperbolic world but doesn't do anything with the concept. Classic dev didn't understand which part of the game was the good part problem.

@@starfeast I get that but I think it should get a bit of a pass for being the first of its kind 😅 The next ones will be better, hopefully.

...except that I've just realised something. If you're on the Moon and someone on Earth points to you, thinking they're pointing into the past, they're actually in YOUR PAST, so they are, in a sense, pointing at the future, which means that the line spirals outwards from that sphere and never hits the centre. My head hurts.

I wanna say something about Science and Atheism on YT, if i may. Ever noticed how Science-RU-vidrs and Atheist-RU-vidrs are basically 'blood-related'? They even all cover Kent Hovind and such people; which aint a Coincidence. The Fanbases don't overlap enough though. Professor Dave pointed out in his video about the Discovery Institute: Some right-now literally fight for a Reverse of the Seperation-of-Church-and-State, which would be devastating. Telltale says to that: We need more Science-Enthusiasts and Atheists in-Office (he even provides infos how to run for Office).

Snap out of it. This is all fake without a hair of truth. PLANK SATELLITE. FINDOUT THE REAL TRUTH. EARTH HAS ALWAYS BEEN THE CENTER.

Good move. Using Kelvin, he'd only get 273 points!

@@ja-si Even more good news: YT has many Science-RU-vidrs.

DemocRATS are known for their lack of hard work

I've not searched really hard, but if you Google "logarithmic map of the universe" you might find it. If you don't, there's plenty of similar images :) I think I've seen that image on RU-vid before, so it might be on a stock image site.

gee thanks, until i read that, i felt kind of stupid for not getting it...

You need to get your head out of that smelly place.

you nee dthat stuff to understand propertly.. but well we can fall deeper as on veritasium or other crap..

There is an observable point while watching any these amazing videos, at precisely 4:12 in, where my capacity for understanding spontaneously breaks down and contracts to an undefinable, shapeless massless state. Then I go have some ice cream

Simple? I'm struggling to understand what's going on lol

Good question. Roger Penrose's Cyclic Conformal Cosmology says that once all mass is gone, there are no longer any clocks to "tell time" anymore, and distance is irrelevant without time, so everything kinda recombines into a single point again then BOOM - another big bang. At least that's how I understand it. I think PBS should speak to this as you are correct that there was a period after the big bang where only massless particles should have existed and so it would be fun to think about what "time" means during that period of the universe's evolution.

@@kylekoschalk7011 time is only relevant if gravity exists. The only information left after black holes evaporate would be massless right? So time wouldn't be needed for the universe to experience. I believe they actually talked about this topic before so i agree with you.(edit yeah time is perceived the same way as if the universe is stretched out or at small point. So it would be instantly. )

Wouldn't it make sense that since everything is the universe, everything scales accordingly?

​@@WellBeSerious12 No, in that case there wouldn't be any expansion.

The Planck length is an imaginary unit of space (not even a single unit itself). Its not anything made of matter and/or energy so I don't see how it would expand since it doesn't actually exist outside of a vague concept much like any other way of measuring things.

@@dgodiex In a deep meaning can you see the difference between an expanding and a non-expanding universe?

The Planck length is just a unit of measurement, so I don’t see how it would expand.

@Solitaire All Int. No Wis or Cha.

i was about to comment, lol i have decided we are all at the center of the universe because if you look at any one point, it looks like the center

@Solitaire Ah, but you do. Unfortunately.

Everything is at the 'centre' of Universal being..This is what the word 'infinite' means to a finite-thinking entity, but within the infinitude there is only a 'centre' when a particular point is indicated. The same for any kind of 'measurement', and 'direction'.. These things do not have any relevance in infinitude, only to the finite entity that indicates them.. "But maybe that is our mistake: maybe there are no particle positions and velocities, but only waves. It is just that we try to fit the waves to our preconceived ideas of positions and velocities. The resulting mismatch is the cause of the apparent unpredictability." (Stephen Hawking, 1988) "Commendation from NASA for research work at Massachusetts Institute of Technology on the Earth's atmosphere and the Moon's surface for navigation of the Apollo spacecraft to the Moon.. Dr. Milo Wolff has found the structure of the electron consisting of two spherical quantum waves, one moving radially outward and another moving radially inward. The center of the waves is the nominal location of the electron 'particle'. These waves extend infinitely, like charge force. All 'particle' waves mix and contribute to each other, thus all matter of the universe is interrelated by this intimate connection between the fundamental 'particles' and the universe. The natural laws are a direct consequence of this Wave Structure of Matter (WSM), thus WSM underlies all of science". spaceandmotion

@@courtneys.7113 Yes. A relative center in an absolute center. Fits well with duality.

If you constructed a 4D map by projecting the movement of all observable objects into the future, that 4D map would be static, and you could navigate it more easily. The big difference would be that in a purely spacial map, you can travel in any direction, and arrive at any point. But in a 4D space+time map, the speed of light limits the directions you can travel, so not every point in the map is reachable.

The scales would be massive, but a 3D map would suffice. In the same way when a sniper takes a extremely long distance shot he have to factor in the rotation of the earth, one would have to factor in all those variables (the ones you mentioned) + time (we can travel " x " distance in " y " amount of time) so that have to be factored in aswell.

That's actually a very complex question, and the way scientists deal with that is by defining various types of distances, such as "luminosity distance" or "apparent size distance" (with their associated maths definitions), that try to take into account different aspects of an evolving universe. These distances often don't even agree, there is no "true" distance at such scales, since you'd need to be able to observe the whole length of space between them simultaneously. But definitions like these help get some sort of handle. Nevertheless, this is why scientists often simply use redshift as a stand-in for distance, since it roughly mimics distance (larger reshift the further away), is something you can directly measure without any interpretation involved, and is a simple unitless number. Hope this helps!

Intergalactic logistics departments must have their work cut out for them

There are various ways of measuring distance to stars and galaxies. But these are only good to about 20 million light-years. Beyond that, the red shift of the light from the galaxies is to calculate their distances. This assumes that the Hubble constant is constant and the expansion of the universe is linear. In other words, we measure the distance to nearby galaxies using some technique and calculate the Hubble constant from that and their red shift. But beyond a certain point, we can no longer measure their distance so we use the Hubble constant and their red shift to calculate their distances. For example, the hot plasma of the early universe is thought to be about 4000K at the time of the recombination epoch, which created the Cosmic Microwave Background (CMB). Since the CMB is about 3K today, it has a red shift of about 1090. Applying the Hubble constant to it gives the distance of about 13.8 giga-light-years. To answer your question, they would use the red shift of the far-away galaxies and the Hubble constant to calculate the distances to the galaxies.

You're onto something intriguing! In the context of the "everything is moving away from us" theory, it's important to understand that the expansion of the universe is not a result of objects physically moving away from a central point. Instead, it's the space itself that is expanding between galaxies, causing the observed redshift in their light. As for the question of variability and uniformity in this expansion, current observational data suggests that on large scales, the universe appears to be expanding uniformly. This is known as the cosmological principle. However, on smaller scales, there can be variations due to the presence of local structures like galaxy clusters, which can have their own gravitational effects. Analyzing the variability of the expansion and understanding its nature is an active area of research. Astronomers use techniques like measuring the redshifts of distant galaxies, studying the cosmic microwave background radiation, and conducting large-scale surveys to gather data and refine our understanding of the universe's expansion. So, while the concept of uniform expansion holds at large scales, scientists continue to explore and analyze the intricate details and variations within the fabric of our expanding universe. It's a captivating field of study that keeps pushing the boundaries of our knowledge.

Dark Energy is a "Force unto itself". It applies constantly, similar to how there is always a downwards pull from gravity on earth.

Hey, can you please share a link to that particular paper? I couldn't find it.

Yes, For example the Aharonov-Bohm effect is usually taken to be a demonstration that the complex (as in complex number) nature of the wavefunction of the electron is something physical that can be measured and not just a trick to make the mathematics nicer.

I've always wondered how they can estimate the age of the universe at 13.7 billion or whatever, because a) they can't see it all, I believe they think they see 4%, but also, I might be wrong with the number, but it's substantially more than 13.7, I seen somewhere the observable universe is about 46 billion lightyears, but if the universe is 13.7 billion, how can they see light that's travelled 46 or whatever billion lightyears. I might not understand how it works properly, but it doesn't add up, not to me at least. Surely you'd have to generalise its position forward in time, but how do they do that?

The center is right here on earth and it is in constant motion

They do have a video dedicated to that specifically

@@LuisSierra42 kinda...

Electric and magnetic force are already "split" and it took Maxwell's equations to reunite them.

how do we know that? do you have proof of this knowing that is not just a theory?

In the event of vacuum decay, something like this should happen. Not EM splitting into E and M; they're relativistic transforms of one another and propagate via a single boson, so there's no axis to split along. But theoretically, vacuum decay would break symmetry in the same way that the Higgs field did, so some family of currently massless indistinguishable bosons could divide itself up by turning some of those bosons massive. The forces mediated by the massive bosons would appear to be a totally separate force at low temperature, just like the weak force. There is almost no chance that atoms and nuclei will be stable after that, so no one will survive to test that theory. It's all speculation.

@Solitaire yes

@@davidhand9721 this speculation of yours seem interesting, maybe even correct.

Agreed. “The 2D person on a 3D planet can’t point down” finally made it click for me.

That would be in the past. Everything is moving away from that past point. The “center” of the universe the way I understand it doesn’t exist in what we see as the present but instead it is the beginning of the universe itself. The big bang is the center.

Think about it...if the universe starts from a single point bang then 14 billion years later no matter what planet you go to and set up a telescope it will aperear that your at the center of the universe because every thing is moving away from your position..and if it don't then the big bang didn't happen 😉 I just wish people would quit worshipping Einstein and simply think for themselves ..lol

@@sailingmohican2767 I appreciate what you're saying, but people take Einsteins word because they don't understand fully, so it's not really a matter of think for yourself, when they're trying to educate themselves & they take the common understanding as their understanding. I don't mean this in a rude way, but Einstein most likely understood these things much better than you do. Not a dig like I said, because he understood it better than I do, & you quite possibly understand it better than I do. And I'm not sure if this is what you meant at the end, but I read it as you saying that you don't need to take Einsteins word on the origins of the big bang, but he wasn't the one who originally theorised the big bang.

Just the opposite, see my comment above. High z galaxies have a long axis that points toward the center, i thimk.

I have this same question. There is one region in our expanding universe that has no relative velocity to the CMB. Whereas we are moving 368 km / s with respect to it. What is special about that region? How far away is it?

What if we're in only the most recent big bang? Just as galaxies crash into each other and black holes grow and swallow everything. What if two black holes grow so large and come together, boom,big bang. A cycle that repeats every 100 ish billion years give or take. Just a thought for when you can't sleep ... sorry. ; 》

Time dimension is expanding into the future, but what the remaining 3 dimensions are expanding into? Does it even make sense trying to describe that which doesn't exist?

@@klin1klinom interesting thought, thinking about it makes my head spin lol.

I always try to imagine it with the analogy of a video game world. If you program it to be bigger, it doesn't expand "into" anything. You won't make the world of Skyrim bigger and then you suddenly hit the edge of the Fallout 4 map. Any game world you would make bigger, could forever expand without ever reaching anything that is not part of said game. The game world expands into itself. Its expansion creates new space that wasn't there before.

@@AliothAncalagon yeah, that's a good analogy. And that seems to be the point of view I usually see it discussed from, or at least that is just growing, it doesn't need anything to grow into. But this growing hypersphere idea seems like it allows for other possibilities to me, although I really have no idea.

@@johnretherford592 Absolutely, other possibilities aren't entirely off the table.