If biology/life relies on our 3D universe's physics and considering a 4D (or higher) universe would have different...

If biology/life relies on our 3D universe's physics and considering a 4D (or higher) universe would have different physics, then is life even possible in higher dimensions? Is there a 4D alien next to me right now?

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In a 4D universe gravity and electric forces would presumably vary as the inverse cube of distance.
Stable planetary orbits could not exist. I mean orbits which the body re-traces time after time after time. That's easy to prove.
I don't think atoms would exist either but that's a trickier question.
Life (or organized matter in general) demands a certain complexity of competing forces.
For example the regular spacing of a crystal lattice is because attractions and repulsions balance at certain distances.
Complex molecules (organic chemistry) are even more dependent on those balancing acts.

I thought we live in le 12 dimensional string universe

>Is there a 4D ayy next to me right now?
Actually I'm spooped now. There probably is.

>In a 4D universe gravity and electric forces would presumably vary as the inverse cube of distance.
What's the basis for that assumption?

>thinks we're living in a 3D universe
>doesn't understand any part of relativity
good one user

If you aim a flashlight at something, the beam gets twice as wide at twice the distance. Since the circle of light is expanding in two dimensions (the ones at right angles to the direction of beam propagation) the light is "diluted" to cover 4 times the area.

Imagine a "flatlander", a being confined to the surface of a plane. The beam of his flashlight would form a triangle. It would be twice as wide at twice the distance, but it can't expand in the 3rd dimension because there IS no 3rd dimension. So the light is only half as bright at twice the distance.

Gravity diminishes the same way, as the inverse-square in 3D space. Note: if the exponent wasn't exactly 2 but, say ,1.999999 or 2.000001 it would easily be detectable by it's effects on planetary orbits.

With one additional spatial dimension, gravity and light would weaken as the inverse-cube of distance, simply because there are more directions they can expand into.

The 'hidden" dimensions don't matter if
. they're curled up and there's no place to go. You just run in circles.
. forces cannot move in those directions.
Some versions of string theory pre-suppose that only gravity can leave our 3-dimensional "brane" because gravitons are closed string-loops. Electrons and quarks and photons are open strings with their ends firmly stuck to the brane.
If this is right, gravity should no longer be inverse-square at very small distances. Instead, it would strengthen rapidly as the spacing between objects shrank. This has been tested down to about a millimeter and there's no evidence of it yet. The tests are difficult because such small objects don't exert much gravitational force.
The possibility that gravity is stronger than expected at sub-atomic distances is what gave rise to those scare stories about the LHC inadvertently creating minuscule Black Holes which would destroy the Earth.

Brainlet here, I can barely visualize 4d. Nigga how am I supposed to comprehend 12 dimensions!?

Relativity does not call for a 4th SPATIAL dimension. Newbies think "curved" space implies a higher dimension for 3-space to be "curved in".
It's a common misconception. 2-D beings living on the surface of a globe could deduce their world had "intrinsic" curvature by measuring triangles painted on the surface.
An actual "radial" direction is not needed for the surface to have the properties it does, no more than a flat plane requires an up/down direction.

youtu.be/lVDaSgyi3xE

I think there's another thread currently running on Veeky Forums on that very topic.
You're right. 4 is hard enough. You just have to give every point N coordinate-values (where N is the number of independent dimensions), deal with the resulting mathematics, and abandon mental imagery.

That actually makes a lot of sense.

>how am I supposed to comprehend 12 dimensions!?
that's what mathematics is for. if you could "visualize" everything, there would be no need for it.

The only way a 4th dimensional being could be standing by you without you knowing is if it were 1 dimensional. Theres a lot of reasons why lesser dimensional objects don't exist in higher spaces, so it is unlikely.

So what about a 57834985340957234097676-dimensional universe? Do stable orbits exist there? Has anyone gone through all the possible dimensions and checked whether atoms/planatery systems/life can theoretically exist there?

There's actually a paper that discusses this, if I find it again I'll post it here

What about 12 dimensional time? I can barely visualize 2d time. How am I suppose to comprehend 12 dimensions of time?

Light, sound and gravity would be really fucked up in a 4d universe.

Orbits are stable only in 3+1.

It's like knowing that, given any two consecutive integers, only one, at most, can be prime. You don't have to check every possible case.

I'd certainly be interested in seeing the link.
Aside: Hard SF writer Greg Egan wrote a trilogy, "Clockwork Rocket", which takes place in a universe with a different metric. Different frequencies of light travel at different velocities and time runs FASTER at high speeds. Interesting and the mathematics all works out.

His latest book though is set in a 3+2 universe. That is, two time dimensions. It's so bizarre that I gave up trying to follow after only a chapter or two.

do sub atomic particles even experience multi-dimensional space/time? or from their perspective is it all 1 dimensional space with 0 time?

You said orbits are stable only in 3+1, but what do you mean, like, 3 real space dimensions and one time dimension?
What about Imaginary dimensions?

Visualize the first, and second, try your best at the third, and then think about n dimensions. Notice the change from dimension to dimension on each step and apply that to an infinite number.

Visualizing a particular solution in 40 dimensions is impossible for most mortals, but do the math and use what you know about a standard vector space.

Yeah. Physicists write "3+1" as shorthand for 3 space dimensions and 1 time dimension.

Not sure in what sense you're using the word "imaginary". If it means "doesn't exist", then it cannot affect how the universe works.
Physicists sometimes used concepts like "imaginary time" to reformulate problems in an easier-to-solve form, such as to eliminate a hard-to-handle boundary condition. SFAIK, they always translate the results back to "real" dimensions to understand what the answers mean.

So far as we know, atomic particles "live" in the same dimensions we do. As explained, the most elementary particles might experience additional dimensions. No experimental proof of that yet. WE experience the same extra dimensions, of course, but don't notice them because of our size.
The wire stretched between telephone poles is, to us, a close approximation of a one-dimensional object. An ant on the wire perceives its 2nd dimension (its circumference) easily.

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