2
votes
2answers
253 views

Did the universe always have 4 space time dimensions?

Is the dimensionality of spacetime in all usual models constant?
7
votes
3answers
985 views

How can we be so sure the universe has 3 dimensions?

I'm just a layman here so please bear with me if I don't get all the words or theories by correct name or whatever. I hope it will be clear enough what my question is. Here goes: When I read articles ...
2
votes
3answers
278 views

Can extra dimensions be too large to be observable

String theory postulates 6 extra dimension, all too small to be observed. The best description of a small dimension is that of an ant walking on a flagpole: The ant observes that the flagpole allows ...