Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Infinity (was Re: Car acceleration)



I was speaking of the lay use, not the mathematicians'. Bad usage: "almost
infinite."

You refer to Aleph null, Aleph one, etc. Gamow discussed this in "One Two
Three Infinity."

bc

countable means can be put in one to one correspondence with, say, the +
integers (many sets are countable). More:

http://www.jcu.edu/math/vignettes/infinity.htm


Michael Bowen wrote:

At 11:15 2002/02/04, Bernard Cleyet wrote:
Like unique (and infinite), I thought wrong could not be compared.

I found this comment rather interesting. Are you sure about the
non-comparability of "infinite"?

I'm no set theorist, but I was under the impression that there were at
least two flavors (and "sizes") of infinity: the cardinality of the set of
real numbers ("uncountable") and the cardinality of the set of counting
numbers ("countable", a peculiar choice of jargon that I have never quite
understood). The infinities have different "sizes" in the sense that it is
not possible to set up a one-to-one correspondence between the two number
sets. I once saw a clever way of setting up a one-to-one correspondence
between the counting numbers and the rationals (thus showing the set of
rationals also to be countably infinite), but it was so cute that it has
since slipped out of my mind.

I'll happily go along with the uniqueness of "unique". :-)

--MB