Chaos and Stability: Exploring the Possibility of a 4D Universe

[Gold Barz]

Would it be too chaotic to allow for stability to arise? would it be "dead"?

 

[dx]

Stability of what? would what be dead?

 

[Tide]

First, tell us everything you KNOW about 4D physics then we may be able to give you some feedback.

 

[Mk]

I think he's talking about

A) Stable atoms
B) Life

I don't think we know enough about higher-dimensional physics to make any judgments. But things from the fourth-dimension are probably incomparable to anything here. Ehh? How speculative is this thread?

 

[robphy]

Here is my post from recent thread on the dimensionality of space,
which has references to a paper by Ehrenfest:
https://www.physicsforums.com/showpost.php?p=809880&postcount=10

 

[Gold Barz]

Mk is right, I am right now reading and enquiring about how physics would work in multi-dimensional space (eg. a universe with four spatial universe). Is it safe to say that 3D physics and 4D physics are totally incomparable as Mk said, or will it be similar but with an extra spatial dimension?

 

[hellfire]

I suggest you to read the paper of Max Tegmark referenced by robphy in the other thread (you may be interested also in a more extensive paper by Tegmark which contains it: Is ``the theory of everything'' merely the ultimate ensemble theory?). Tegmark gives very nice explanations about the nature of the differential equations in different spatial and temporal dimensions and discusses which cases lead to "well posedness" of initial value problems and predictability.

 

[Mk]

Is it safe to say that 3D physics and 4D physics are totally incomparable as Mk said, or will it be similar but with an extra spatial dimension?

I would assume what viewpoint you are at. If you were 3D looking at the 4D, you would probably think it... inconceivably weird, or just be fascinated by it. If you were 4D looking at something 3D (like you looking at a sheet of paper with a stick figure drawn onto it), it would be normal.

 

[Gold Barz]

Okay, how about this question...would a 4D universe have the constraints of a 3D universe?

 

[Jay-qu]

well firstly I assume that by 4D you mean '4 spatial dimensions' otherwise it is debatable whether or not to include time as a dimension, and then you say constraints, which could be interpereted as laws of physics - ie can't exceed c, things like that.

Final answer: I don't know, and anyone that says they do is lying.

 

[Mk]

Okay, how about this question...would a 4D universe have the constraints of a 3D universe?

No. Much less. Think of the little stick figure moving around (the piece of paper is now a map) only having the options (and combinations) of
left
right
north
south
Then think about yourself - you can move left, right, north, south, you can jump up, and you can crouch. With combinations! Mr. Stick Figure is the one with constraints.
----
Named are the words describing four-dimensional spatial movements. Ana, and kata. For they are the terms for "up" and "down" in Latin.

 

[Gold Barz]

Would a 4D universe would be radically different from a 3D universe, might it be so different that, matter and energy as we know it won't exist over there?