[FOM] Height and Width of the universe
joeshipman@aol.com
joeshipman at aol.com
Sun Jan 20 12:09:08 EST 2008
Here are two theorems of the form "If the Universe is tall enough, it
can't be too narrow."
If there is a measurable cardinal, there is a nonconstructible set.
If there is an inaccessible cardinal, there is a countable transitive
model of ZFC.
What other theorems relate the height and width of the Universe? The
theorem "If there are infinitely many Woodin cardinals, there is no
projective set of reals which is not determined" seems to go in the
other direction than the previous two, but it doesn't really, because
we know there are non-determined sets, and the theorem just says they
don't fall in the projective hierarchy of reals not that they don't
exist.
-- JS
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