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?
If biology/life relies on our 3D universe's physics and considering a 4D (or higher) universe would have different...
Easton Watson
Other urls found in this thread:
Lincoln Green
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.
Jonathan Evans
I thought we live in le 12 dimensional string universe
Brandon Roberts
>Is there a 4D ayy next to me right now?
Actually I'm spooped now. There probably is.
Austin Hernandez
>In a 4D universe gravity and electric forces would presumably vary as the inverse cube of distance.
What's the basis for that assumption?
Michael Clark
>thinks we're living in a 3D universe
>doesn't understand any part of relativity
good one user
Levi Lopez
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.
Michael Cooper
Brainlet here, I can barely visualize 4d. Nigga how am I supposed to comprehend 12 dimensions!?
Dylan Hall
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.
Nathan Lopez