Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca!neufeld
Newsgroups: sci.space
From: neufeld@physics.utoronto.ca (Christopher Neufeld)
Subject: Re: Synchronous rotation
Message-ID: <1990Nov9.194555.26131@helios.physics.utoronto.ca>
Organization: University of Toronto Physics/Astronomy/CITA
References: <7712.273a7b89@uwovax.uwo.ca> <1990Nov9.190858.11889@ns.network.com>
Date: 10 Nov 90 00:45:55 GMT

In article <1990Nov9.190858.11889@ns.network.com> logajan@ns.network.com (John Logajan) writes:
>17001_1511@uwovax.uwo.ca Phil Stooke writes:
>>This produces stresses and movements in the crust
>>which involve some energy dissipation. Therefore energy is slowly being
>>lost from the system, and that manifests itself as a gradual slowing of the
>>rotation period, until syncronous rotation is reached.
>
>Okay -- so where does the angular momentum go?  It has to be conserved.
>
   It goes into orbital angular momentum, boosting the orbit of the moon
(assuming that the moon was originally rotating around an axis parallel,
not anti-parallel to the orbital axis). Our moon is moving away from us
still, as it tries to lock the Earth to face it.
   Velocity in orbit decreases as the square root of the distance from
the centre of rotation, so higher orbits have higher angular momenta,
with an angular momentum proportional to the square root of the
distance.

>- John Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428
>- logajan@ns.network.com, 612-424-4888, Fax 612-424-2853


-- 
 Christopher Neufeld....Just a graduate student  |
 neufeld@helios.physics.utoronto.ca    Ad astra! |  S = k log W
 cneufeld@{pnet91,pro-micol}.cts.com             |    Boltzmann's epitaph
 "Don't edit reality for the sake of simplicity" |