From Feynman "
The Character of Physical Law"
> I think that by an analogy I can give some idea of the
difficulty, in this way. I do not know if you have ever had
the experience - I have - of sitting on the beach with several
towels, and suddenly a tremendous downpour comes. You
pick up the towels as quickly as you can, and run into the
bathhouse. Then you start to dry yourself, and you find that
this towel is a little wet, but it is drier than you are. You
keep drying with this one until you find it is too wet - it is
wetting you as much as drying you - and you try another
one; and pretty soon you discover a horrible thing - that
all the towels are damp and so are you. There is no way to
get any drier, even though you have many towels, because
there is no difference in some sense between the wetness of
the towels and the wetness of yourself. I could invent a kind
of quantity which I could call 'ease of removing water'. The
towel has the same ease of removing water from it as you
have, so when you touch yourself with the towel, as much
water comes off the towel on to you as comes from you to
the towel. It does not mean there is the same amount of
water in the towel as there is on you - a big towel will have
more water in it than a little towel - but they have the same
dampness. When things get to the same dampness then there
is nothing you can do any longer.
... and then he continue to explain how this is related to temperature and entropy.
The whole book is worth reading.
