>On 7/7/10 9:40 PM, Immortalist wrote: >> What sort of things are they if they are things? > > Some Background > http://en.wikipedia.org/wiki/Spacetime > >"The concept of spacetime combines space and time to a single abstract >"space", for which a unified coordinate system is chosen. Typically >three spatial dimensions (length, width, height), and one temporal >dimension (time) are required. Dimensions are independent components of >a coordinate grid needed to locate a point in a certain defined "space". >
Note that many more than 4 dimensions are necessary if you want all the math to work out. I seem to recall having read somewhere that the number that seems to work best is 11.
-- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw