Thursday, January 10, 2013

a boundless universe?

today we talked about the possibility of an infinite universe @ T,R 9:50 am class. my tentative response was perlmutter and schmidt's hypothesis: the universe is expanding at an accelerating rate.

is the universe "infinite?" not in time. U has a beginning, it's ± 13.7 billions years old.

do you mean infinite in the amount of matter? if U has "Z" particles then each particle (in principle) can be counted, provided one has enough time to do it. 

next, is U "infinite" spatially? if it keeps expanding you would think that it keeps getting bigger, reaching more of__. 

it's hard to imagine "space" without at least 2 points, 3 is better (no points no space).  

*this constant widening of U happens in time.
*if U reaches a limit "L," then it stops expanding.
*but then U is the container of space! that is to say, U is being defined as a the expansion of itself, which is kind of circular. 

if U has --or reaches-- a L, then presumably, U cannot be infinite. some hypotheses point in this direction (even a quadrillion, 1015 years is an infinitesimal of "evermore").