>In a message dated 11/11/00 1:16:34 AM Eastern Standard Time,
>[EMAIL PROTECTED] writes:
>
>>The model most often used to describe the expanding universe is the "skin" of
>>a balloon. How literal is that example? Does all matter expand away from a
>>point of origin leaving a void in the center?
>>
>
>
The "skin of a balloon" model is a model of a two-dimensional space
universe expanding in time. There is no "void" in the center because
the skin of the balloon is all there is: the universe has only two
dimensions of space.
Now generalize this "skin of a balloon" model to a universe with not
two but three dimensions of space. If it helps, you can think of our
three space dimension universe as being the "skin" of a four
dimensional balloon--and it is the four dimensional balloon that
blows up.
GSV It Doesn't Help Me to Think of It That Way
