Been thinking about dark matter and dimensional physics. Kaluza-klein compaction as well. Like... If additional dimensions could be periodic, or could fold and unfold, and matter can exist in those, couldn't that explain dark matter?
Idk if all this makes sense, I haven't had water in a while.
The compaction theory says that there is/are additional spatial dimensions, but they are compacted and curled around their own fields until they become infinitely small, which is why we can't observe them anywhere no matter how small our instruments are, and why they don't seem to have an effect on real-world physics. But dark matter is used as an explanation for when something happens with matter or energy that requires more mass than we can perceive there.
What if dark matter is simply spaces where the additional spatial dimension uncurls, providing an additional plane for mass to be stored?
The problem with this is that dark matter does not interact with light or any electromagnetic radiation at all (as far as I can find)
If there was indeed a fourth spatial dimension we can't see, and it uncurls in those clouds of dark matter, light would (presumably) be able to travel that fourth dimensional field, yet it doesn't seem to, because light doesn't take any longer to move through dark matter clouds. (Technically. Kind of. I'll get to the gravity bending part.)
This could potentially be explained by that field still being closed to our perception, therefore its dimension even when uncurled somewhere else is imperceptible. But if light could travel across a fourth dimension, it would take time. That we know, that we can observe. Light across space requires time. So, theoretically, light across a fourth dimension would take longer to travel.
SO if light within these clouds of dark matter were moving across a fourth spatial dimension, the length of time would be observably longer, even if we didn't know why.
That said, dark matter does (as far as we can tell) have its own mass. This is why it seems to interact with the fundamental force of gravity.
Gravity bends time. Gravity also warps the movement of light. I suppose, technically speaking, it would be entirely possible for the fourth dimension's gravitational spectra to bend the apparent location of light (which is what dark matter does), thereby allowing light to pass through without altering our perception of how long it took (because we expect traditional gravity alone to bend it). Because we don't know the shape of the fourth dimension, and we can't see the accurate location of that light. So we wouldn't be able to see a path through an additional dimension, and would only be able to see a path in 2 or 3 dimensions.
This could kind of also explain the strength of gravity in this invisible mass. More mass in that space thanks to the unfolded fourth dimension, and gravity as a fundamental force wouldn't magically bounce back to 3D math when it has 4D mass. So even where the fourth dimension curls up/ends, the impact on spacetime curvature (gravity) within it would continue past that boundary and affects ordinary matter. To a point, this interacts with the theory of the graviton particle but I'm ignoring that rn.
Moreover, that fourth spatial dimension would still be imperceivable to us, so we wouldn't see the fourth dimension of any objects/mass in the field (so we see less than is actually there). But we could see its shadow (how its mass is warping spacetime and therefore gravity).
So time could also (potentially) play differently within the fourth dimension, which could maybe account for the expansion of the universe speeding up.
Idk. It's interesting to think about. Anyway if you have anything you'd like to chime in on please do
