James
Clerk Maxwell, explained Koteks, a famous Scotch scientist who had
once postulated a tiny intelligence, known as Maxwell's Demon. The
Demon could sit in a box among air moleculesthat were moving at all
different random speeds, and sort out the fast molecules from the
slow ones. Fast molecules have more energy than slow ones.
Concentrate enough of them in one place and you have a region of high
temperature. You can then use the difference in temperature between
this hot region ofthe box and any cooler region, to drive a heat
engine. Since the Demon only sat and sorted, you wouldn't have put
any real work into the system. So you would be violating the Second
Law of Thermodynamics, getting something for nothing, causing
perpetual , motion. "Sorting isn't work?" Oedipa said.
"Tell them down at the post office, you'll find yourself in a
mailbag headed forFairbanks, Alaska, without even a FRAGILE sticker
going for you." "It's mental work," Koteks said, "But
not work in the thermodynamic sense."
Everyone
who has studied Science knows that Maxwell´s demon is a mithological
creature as important as Schödinguer cat. In my opinión, it´s also
an interesting mental experiment, similar to Einstein´s best ones.
We
can see in the picture how the demon separates arbitrarily the hot
molecules, the red ones, from the cold ones, which are blue. And this
generates a temperatura diferential that, as we are told in the text,
could do thermodynamic work.
So,
by doing this, the demon would be violating the second law of
Thermodynamics, because he would have created energy from nothing.
No comments:
Post a Comment