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I don't know if science has an answer or not. It would seem a natural question to ask.

If you asked me, my guess would be a sphere. The BB would imply such a shape. What say you? Is it spherical, cubed shape, oval or what?

In every direction astronomers can look space-time itself appears to be as flat as a board, while Relativity suggests it should curve back on itself. Quantum mechanics suggests being both flat and curved is probably correct.

General Relativity, the mainstream cosmological theory for the last 90+ years suggests, in its most parsimonious interpretation, that the universe's shape is a hypersphere: a 4-dimensional sphere. To our 3-dimensional view of things, space-time appears flat and also infinite, however, straight parallel lines will eventually intersect (if drawn out far enough) as a consequence of the curvature in the unseen 4th dimensional direction.

However, this interpretation requires the 4th-dimensional curvature of space-time to be able to be modeled by positive-valued numbers in linear progression. General Relativity doesn't require this. If actual modelling of curvature were to require negative numers or non-linear progressions of numbers, then the universe could be 4th-dimensionally shaped like a parabola or a horse's saddle, both of which are open-ended with no edge, and therefore infinite, or a more complex closed shape like a torus (donut-shaped).

It's interesting to consider the possibility of seeing the back of your own head without a mirror.

If the universe makes sense, then in might circular, but this kind of circularity is probably unrelated to shape or curvature. Circular in all 'dimensions' of spacetime. So a distant point in space in front of you is the same as a distant point in space behind you. And a distant point in time in your future is the same as a distant point time in your past. (And the only viable model to the end of our part of the universe is the Big Crunch.) Plus the universe should have perfect symmetry so there is an identical anti-universe out there with an identical anti-you. (But can you 'two' work together in some sense, now that you know this, or is that impossible? Ha! )
So obviously, the universe should be bigger than the part that came from the Big Bang.
Plus the universe/multiverse may be structurally circular in other ways too, but that's an extremely deep issue, and I have never seen it discussed anywhere.

And if the universe doesn't make sense, then I don't really care, because then we are just wasting our time here. Then metaphysics is every restricted and can't even attempt to address some of the big questions (for example: why are we, humans, here right now?).

It has no shape, it's just endless space forever.

When what the 'Universe' is, is actually understood in a logically reasoned way, which makes sense, then the 'shape' of the Universe becomes crystal clear as well.

Philosophy Explorer wrote:If you asked me, my guess would be a sphere. The BB would imply such a shape. What say you? Is it spherical, cubed shape, oval or what?

I know you're long gone but I'm going to answer anyway.

This may seem picky, but obviously we couldn't model a Universe in which it takes 3 numbers to define spatial position by using the 3 dimensional geometrical concept of a sphere. We could only use such a mathematical concept to model the spatial aspects of a 2 dimensional Universe. In that model, the 2 dimensions of space would be represented by the surface of the sphere. We could use a hyper-sphere (the 4 or more dimensional analogue of a sphere). I'm pointing this out explicitly, despite it perhaps seeming obvious, because the comments of lots of people on this kind of subject seem to show that they don't grasp this. So best to be clear about it.

The trouble is, it is impossible to visualise such exotic mathematical objects as hyper-spheres or hyper-toruses. And people like to be able to visualise models, even though they're only models. Mathematically, we can add as many dimensions as we like. We can just keep applying the mathematical/geometrical rules that we used for lower numbers of dimensions. But for the sake of visualisation, we take it down a dimension or two, while never forgetting that this is what we have done. And, of course, we must never forget that what we're talking about is finding a mathematical model that best describes what is observed.

So, we think of ourselves as living in a 3 dimensional space because we have observed that it takes 3 numbers to uniquely define the position of an object. Rene Descartes, the namesake of "Cartesian coordinates", reportedly observed it by watching a fly on his bedroom ceiling.

https://wild.maths.org/ren%C3%A9-descar ... ly-ceiling

The idea that we live in a 3 dimensional spatial world stems from these observations. It is an empirical fact, as opposed to being some kind of logically certain axiom. So we could imaging what it might be like if things were different; if we lived in a 2 dimensional spatial world. If we lived in a world like that and found that a long journey in a straight line in any given direction brought us back to our starting point then we could model that behaviour as a sphere.

A Poster He or I wrote: ↑August 21st, 2013, 7:00 pm General Relativity, the mainstream cosmological theory for the last 90+ years suggests, in its most parsimonious interpretation, that the universe's shape is a hypersphere: a 4-dimensional sphere. To our 3-dimensional view of things, space-time appears flat and also infinite, however, straight parallel lines will eventually intersect (if drawn out far enough) as a consequence of the curvature in the unseen 4th dimensional direction.

However, this interpretation requires the 4th-dimensional curvature of space-time to be able to be modeled by positive-valued numbers in linear progression. General Relativity doesn't require this. If actual modelling of curvature were to require negative numers or non-linear progressions of numbers, then the universe could be 4th-dimensionally shaped like a parabola or a horse's saddle, both of which are open-ended with no edge, and therefore infinite, or a more complex closed shape like a torus (donut-shaped).

I report this contributor for posting a reply which is concise, lucid, intelligible, and correctly represents the current state of our knowledge. The contributor should be aware that such replies are not acceptable. Shame on you sir (or madam)!

Alan Masterman wrote: ↑November 17th, 2020, 5:48 pm

A Poster He or I wrote: ↑August 21st, 2013, 7:00 pm General Relativity, the mainstream cosmological theory for the last 90+ years suggests, in its most parsimonious interpretation, that the universe's shape is a hypersphere: a 4-dimensional sphere. To our 3-dimensional view of things, space-time appears flat and also infinite, however, straight parallel lines will eventually intersect (if drawn out far enough) as a consequence of the curvature in the unseen 4th dimensional direction.

However, this interpretation requires the 4th-dimensional curvature of space-time to be able to be modeled by positive-valued numbers in linear progression. General Relativity doesn't require this. If actual modelling of curvature were to require negative numers or non-linear progressions of numbers, then the universe could be 4th-dimensionally shaped like a parabola or a horse's saddle, both of which are open-ended with no edge, and therefore infinite, or a more complex closed shape like a torus (donut-shaped).

I report this contributor for posting a reply which is concise, lucid, intelligible, and correctly represents the current state of our knowledge. The contributor should be aware that such replies are not acceptable. Shame on you sir (or madam)! :)

That individual was last active on July 26th, 2018, at 12:55 pm, so maybe that individual was removed for such offenses.


So, to give an acceptable answer, I say, the shape of the universe is like a the shape of a dog. More specifically, a pit bull. The reasons are obvious.

For people who do not know what that shape is like:

https://www.barkspot.com/wp-content/upl ... 6x1024.jpg

Alan Masterman wrote:I report this contributor for posting a reply which is concise, lucid, intelligible, and correctly represents the current state of our knowledge. The contributor should be aware that such replies are not acceptable. Shame on you sir (or madam)!

I agree with your tongue-in-cheek praise of that contributor. The poster you're talking about ("A Poster He or I", which was a play on the term "a posteriori") was a person who I got to know quite well when he was here. He was definitely one of the more lucid and sane posters on this site and we had some interesting conversations on the philosophy of science particularly.

Steve3007 wrote: ↑November 18th, 2020, 5:27 am

Alan Masterman wrote:I report this contributor for posting a reply which is concise, lucid, intelligible, and correctly represents the current state of our knowledge. The contributor should be aware that such replies are not acceptable. Shame on you sir (or madam)! :)

I agree with your tongue-in-cheek praise of that contributor. The poster you're talking about ("A Poster He or I", which was a play on the term "a posteriori") was a person who I got to know quite well when he was here. He was definitely one of the more lucid and sane posters on this site and we had some interesting conversations on the philosophy of science particularly.

You have explained why he would leave.


I believe the correct response to the opening question is, we don't know. (Even if the post under discussion gives the best guess.) Due to people being troublesome things, they don't tend to like that as a response to something, so they tend to just make stuff up when that is the case. So, until someone proves it one way or another, I will stick with my theory above.

Jack D Ripper wrote:I believe the correct response to the opening question is, we don't know.

I'd say the correct response is that it depends what our purpose is in using the concept of shape as a device for describing the observed properties of the universe.

So, until someone proves it one way or another, I will stick with my theory above.

Fair enough, although the reasons for proposing the shape of a pit bull aren't immediately obvious to me. Is the character of the pit bull a factor, or is it just the shape? Would, for example, a poodle serve just as well?

Philosophy Explorer wrote: ↑August 20th, 2013, 7:57 pm I don't know if science has an answer or not. It would seem a natural question to ask.

If you asked me, my guess would be a sphere. The BB would imply such a shape. What say you? Is it spherical, cubed shape, oval or what?

Since all shapes can only be determined by the negative space around them, it is clear that the universe itself can only be shapeless since their is no space beyond it.
The universe itself does not extend into anything external.