Do we really have more than three spatial dimensions?
In Einstein’s relativity and the Standard Model, we only have three spatial dimensions. But there could be more, and many think there are.
From any point in space, you are free to move in any direction you choose. No matter how you orient yourself, you can travel forwards-or-backwards, up-and-down, or side-to-side: you have three independent dimensions that you can navigate. There is a fourth dimension: time; we move through that just as inevitably as we move through space, and via the rules of Einstein’s relativity, our motion through space and time are inextricable from one another. But could additional motions be possible? Could there be additional spatial dimensions beyond the three that we know?
This has been a question that physicists have entertained for about than a century, and that many mathematicians and philosophers have wondered about for significantly longer. There are numerous compelling reasons to consider the possibility, but there’s also the evidence we have from our Universe: both from a mathematical point of view and from a purely physical point of view. Although the physical consequences that would arise from extra spatial dimensions have tight constraints on them, the mathematical possibilities are just as…
