If there turned out to be more than 3 spatial dimensions, how would we be most likely to make that discovery?

Question

Again I stress - SPATIAL dimensions. Currently, physics considers reality as a matrix consisting of 3 dimensions of space and a 4th dimension of time. For this question, all dimensions involved are entirely spatial, not temporal. What technology do we have that might be able to touch upon such a concept? Any? Even just in theory?

Answer 1

Time is not spatial dimension ... there are only 3 spatial directions namely X, Y and Z.

If you have some knowledge about Theoretical Physics, you can invent as many dimensions as you like as Einstein did so that he may prove his Relativity thoery.

There are no more spatial dimension then as we know today atleast as far the knowledge goes today.

Answer 2

We have no equipment that could detect this.

It is apparent that if there are additional spatial dimensions then they are not visible at normal energies. We do not know really why this would be so, but the best guess would be that they are only apparent at very, very high energy. We cannot reach such energies.

They would be apparent in experiment by particles moving orthoganally to the 3 dimensions we know - ie particles would appear and disappear.

Answer 3

There are a couple ways of probing extra dimensions, depending on exactly what kind you have in your theory.

For large (micrometer size) extra dimensions, you want to probe them using gravity. By measuring the strength of gravity at very tiny distances, experimenters try to verify the inverse-square law of Newton, which only works in 3+1 dimensions. If there are extra dimensions, these experiments will see the strength of gravity increasing faster than it should in 3+1 dimensions. So far, these experiments have ruled out extra dimensions larger than about a micron.

For small extra dimensions, you can see their effects in the particle spectrum. A particle with momentum in the curled-up extra dimension is like a string that has been plucked. It has lots of extra energy. Since we can't see the extra dimension, the energy looks just like mass in our 3+1 dimensions. So if we see particles that look just like ordinary particles but have lots and lots of extra mass, these could be ordinary particles with momentum in extra dimensions. Such particles are called Kaluza-Klein (KK) modes, and might be seen in future collider experiments like the LHC.

Another possibility is that gravitons (quanta of gravitation) that escape into extra dimensions might be produced in collider experiments. Since the only way to see these would be as lost energy and momentum, I would imagine it's hard to distinguish them from ordinary neutrinos, but people are looking for them too.

There are a few other methods, but these are the big ones. No evidence for extra dimensions has ever been seen. See http://pdglive.lbl.gov/Rsummary.brl?nodein=S071&fsizein=1 for the full technical details.

Answer 4

Since we're going on the purely theoretical, my answer is, we'd stumble into it. And if we were lucky, we'd be able to stumble back out and propose it to, as Schafer said, 'the nonces at Cambridge'. Where given the usual run of things it would be poo-pooed for some time, sliced and diced and finally, just before the known dimension we're in is scheduled to go ' poof ', be awarded a 'possible' on their scale of from here to eternity.

Answer 5

That concept is one that the human mind is no where near able to process, and hence will likely not be discovered for a very very long time. It would be like finding a never before seen visible color. Can you even possibly imagine what that might look like? No, because you have nothing to compare it to.

Answer 6

its not possbile ^^. the exact point of time being a dimension is that it isnt that much different from a spatial dimension when talking in a coordinate system.

Answer 7

I don't think it really matters to anybody but theoretical nonces in Cambridge