Linked Questions

1
vote
0answers
40 views

Why are we in 3 spatial dimensions? [duplicate]

I am very curious to find if there is any reason that why are we in 3 dimensions not in any other like 1D would be hard almost impossible but 2D could have been possible, or what about 4D or in ...
6
votes
1answer
179 views

Spacetime has an infinite number of choices for differentiability. Coincidence?

Spacetime can be modelled using a four-dimensional topological manifold. Say we denote the manifold using $(M, \mathcal{O})$ where $\dim M =d$. The structure $(M,\mathcal{O})$ is not sufficient for ...
5
votes
3answers
2k views

Why are there 4 Dimensions and 4 Fundamental Forces?

Is it a coincidence that there are four fundamental forces and four spacetime dimensions ? Does a universe with three spacetime dimension contain four fundamental forces? Can magnetism be realized in ...
11
votes
2answers
630 views

A change in the gravitational law

What would happen if the force of gravitation suddenly starts varying as $1$$/$$r^3$ instead of $1/r^2$ ? Would the symmetry of universe now seen be disrupted?
-2
votes
1answer
116 views

Is 3 spatial dimensions most suitable to life? [closed]

As we're 3 dimensional beings, it's easy to say that the 3rd dimension is the most suitable for life, because we have trillions of examples of 3 dimensional life and no examples for any other ...
1
vote
2answers
91 views

Does time matter?

Aside from the second law of thermodynamics it seems physics just doesn't care about the direction of time. So does time really matter? What if instead of 3 spacial and one time dimension. 3+0 or 3+2....
2
votes
2answers
353 views

Compactification of dimensions in string theory: Why our Universe has 3 large spatial dimensions?

Is the only way that string theory can respect the principles of quantum mechanics, and Einstein's special theory of relativity, is to formulate it in a hypothetical nine dimensional space? You could ...
8
votes
2answers
803 views

Why doesn't the number of space dimensions equal the number of time dimensions?

It seems as though symmetry is a driving force behind theoretical physics. With symmetry in mind, should we expect that the number of time dimensions should be the same as the number of spatial ...
3
votes
0answers
119 views

Can superstring theories predict our 4 dimensions? [duplicate]

Popular science literature is replete with the necessity for superstring theories to live in at least 10 dimensions, requiring at least 6 of them to be compactified so that they are not observable. ...
1
vote
0answers
138 views

Instability of higher dimensional universes

According to superstring theory, there are at least 10 dimensions in the universe (M-theory actually suggests that there are 11 dimensions to spacetime; bosonic string theories suggest 26 dimensions). ...
2
votes
1answer
186 views

Why a 3D Universe?

The universe as it stands is perceived by us to be 3 dimensional. Why is it that the universe formed into 3D space and not 4D or 5D space for example?
5
votes
1answer
262 views

Are dimensions a fundamental property of the universe or an emergent result of other physical laws?

Are space-time dimensions a fundamental property of the universe or an emergent result of other physical laws?
0
votes
2answers
220 views

How can we be certain our world has only three spatial dimensions? [duplicate]

It's common knowledge that the universe has three spatial dimensions, and one temporal. But how can we be so sure? Physics tells us that vector forces act independently along different dimensions, so ...
0
votes
1answer
77 views

Why spacetime has 3+1 large dimensions and remaining higher dimensions underwent compactification? Why spacetime hasn't got eg. 5+4 or 3+5 dimensions?

Yesterday I wrote very, very big thread which proved to be too broad, so according to your instructions I divided it. Content is unchanged. I read that it might be related to the phenomenon of ...
8
votes
1answer
324 views

Plausible explanations for 3 large space dimensions

Every now and then I see accounts of models that claim to explain why we experience only 3 large space dimensions (locally, i.e. within cosmic horizons and outside black hole horizons). One such of ...

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