> Yes, there are many conjectures which are widely believed to be true i.e. the
> four-color conjecture, Fermet's last therom, the closed universe, the existence
> of black holes, and these can all be regarded as hypothesis, with the possible
> excepton of the closed universe, because they can be tested, we just don't know
> how to do it yet.
This is a side point, but I had heard several years ago that the
four-color problem was now considered solved, and thus it was the
"four-color theorem" rather than hypothesis or conjecture. So I ran off
and did a web search in an attempt to confirm this. The answer is in fact
a bit murky, as it's *apparently* been proven by computer enumeration of
all possible configurations, but no one knows whether there might be a
flaw somewhere in the process, as was true of previous human attempts,
and it took too much processing to be humanly checkable. For anyone who's
interested, I did find some interesting websites, including
http://sdcc14.ucsd.edu/~fillmore/blurbs/fourcolor/fourcolor.html
which has previous proof attempts, diagrams, and discussion.
--Eva,
who still has a few coloring books somewhere that are mostly colored in
using only four colored pencils