**Ask a monkey a physics question thread**

[wufwugy]

so i hear that there is no edge to the universe and that physicists don't know if it's finite or infinite. doesn't the universe not having an edge mean it's infinite?

[NightGizmo]

so i hear that there is no edge to the universe and that physicists don't know if it's finite or infinite. doesn't the universe not having an edge mean it's infinite?

If it's finite but edgeless, then it wraps around.

[OngBonga]

so i hear that there is no edge to the universe and that physicists don't know if it's finite or infinite. doesn't the universe not having an edge mean it's infinite?

Does the surface of a sphere have an edge? Is it infinite?

[wufwugy]

Does the surface of a sphere have an edge? Is it infinite?

it does, but one that can only be perceived in at least 3 dimensions.

If it's finite but edgeless, then it wraps around.

are you saying that if we were an infinitely cloned ftl spacecraft, we could travel from an origin into every 3d direction and eventually run into each other?

[OngBonga]

it does, but one that can only be perceived in at least 3 dimensions.

Yeah there's limitations to that analogy, but it at least demonstrates that boundless does not equal infinity.

I have a phsyics question... how does a dead woman cure a brain tumour?

[MadMojoMonkey]

so i hear that there is no edge to the universe and that physicists don't know if it's finite or infinite.

The collective IDK is the important thing to take from this.

If there is an edge, it has not yet been detected.

doesn't the universe not having an edge mean it's infinite?

Not necessarily. NG and ong both make interesting points.

The surface of a sphere has no edges, but is a finite area. Same for a torus.

Fractals are mathematical objects with interesting properties. They can have an infinite perimeter enclosing a finite surface area.

An "infinitely bumpy" surface may have infinite area, yet enclose a finite volume.

All of this is easily extrapolated into higher dimensions mathematically. The fact that all my examples are about area, and not volume is intentional. It's hard (impossible?) to visualize a volume as the infinite bound of a finite 4-dimensional object. Still, there is no reason that is not a valid description of the universe.

Valid doesn't mean correct, merely possible given our current understanding.

[OngBonga]

The surface of a sphere has no edges, but is a finite area. Same for a torus.

Bolded goes along my stoned line of thinking.