Thursday, January 10, 2013
today we talked about the possibility of an infinite universe @ T,R 9:50am 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 they then each particle can be counted (provided one has enough time to do it).
next, infinite spatially?
if it keeps expanding you would think that it keeps reaching "more of" something.
space has to be defined as a distance between 2 points. without points "to breach" there is no space.
*but this widening of U is measured in time.
*if U reaches X a limit "L" then it stops expanding. there is always a ∆L of expansion.
*but then U is the container of space, which is... space! that is to say, U is being defined as the expanding of space then it's the expanding of itself, which is kind of circular.
if U has a L, then presumably, U cannot be infinite. some hypotheses point in this direction (even a quadrillion, 1015 years, is a small infinitesimal of "evermore").