2 ms·
> Our established 3 dimensions are actually compact, i.e. loop around Do they not loop? What other option is there? I assume you can't sail off the edge of the
by fc417fc802 2y ago
> Our established 3 dimensions are actually compact, i.e. loop around
Do they not loop? What other option is there? I assume you can't sail off the edge of the disk, so to speak.
- AnimalMuppet 2y agoOption 1: They loop. Option 2: They go on forever without looping. Option 3: They end - there is some kind of boundary to spacetime.
- trhway 2y agoThe expansion of the space is the feature which prevents any physical process inside to distinguish between those options. Kind of a hack - make compact Universe, add expansion and it would inside look and feel indistinguishable from non-compact.
- fc417fc802 2y agoHow does option 2 fit with the big bang? The obvious issue (at minimum) being accounting for the CMB.