Message-Id: <199801280059.QAA21026@perry.geo.berkeley.edu>
Date: Tue, 27 Jan 1998 16:58:31 -0800
To: pinhole@exploratorium.edu
From: suzanna@seismo.berkeley.edu (Suzy Loper)
Subject: rotation of Earth
Hello pinholers,
Following is an excerpt from an e-mail question I got from one of
my former physics students, now a freshperson at UCSB. Since he still
seems to hold the misconception that I know everything, can you help me out
on this one? (-:
I can think of some obvious reasons why his friend is wrong about
the atmospheric friction, but I don't know what "gravitational friction" is
or why the Earth and moon are slowing in their rotation.
Thanks!
Suzy Loper
"Oh: the reason why I'm e-mailing: I had an argument with a friend
during dinner about why the moon has almost stopped spinning over the
years. I also explained that, eventually, the Earth will stop spinning
because of the Sun's gravitational friction with the Earth. Is this
true? He says that the earth will stop spinning because of the friction
of the atmosphere with the mountains on earth. Who's right? What is
the right answer? I remember vaguely that you explained this phenomenon
is physics last year. Could you expain? Thanks."