🚀 go-pugleaf

Ethan Vishniac says:

> Science fiction writers have used the word in a slightly different sense.
> The idea is that space-time might have umpteen dimensions, only four of
> which are readily apparent.  Then something that is near us *in an
> unusual direction* is referred to as another "dimension",  (as in
> "The Giant Cockroach from the Twelfth Dimension that Ate Detroit").
> 

An article in Scientific American (March, 1985) describes the universe as
having at least 7 (I think; I don't have my copy handy) dimensions and at most
11 dimensions.  Above 11 dimensions, a lot of math that physicists use to
describe said universe breaks down.  While I have no complaints on the article
(or on Scientific American in general -- an excellent magazine!), due to the
audience addressed, often some very interesting tidbits are lacking in articles
like this one.  Questions I have include:

Are the N-4 dimensions named (and if so, what are their names)?

Do the dimensions come in related groups (i.e., we perceive 3 dimensions of
`space' and 1 of `time'; does time come in 3 directions maybe?)?

Do we perceive the N-4 dimensions?  If so, how?

Why does `time' appear to be unidirectional?

Are there dimensions other than `time' that appear to be unidirectional?

I have often suspected (in my casually interested, but not highly educated in
physics mind) that the number of dimensions must be prime, and am very
gratified to hear that the likely number (11) is prime.

Well, that's probably enough for now.  Can any of you physicists shed any light
on these questions to a mere dabbler in physics?
-- 
	Marty Shannon
UUCP:	ihnp4!eagle!mjs
Phone:	+1 201 522 6063