Re: Extinction

["Michael" <tons@ccs.netside.com>]

I agree with you.  I don't see a major bolide impact as being "fair" 
experimentation either.

I spoke with an astonomer this morning.  He stated that the sun 
oscillates in the plane of the galaxy enough to disturb the Ort 
Cloud.  He also says that the sun is stable enough that fluctuations 
in the amount of energy given off is enough to change the weather but 
not over long periods.  However, changes in the earth's orbit as a 
result of interaction with the other planets does happen and may be a 
cause of the Ice Ages.  (I'm sure some of you know this, but since I 
didn't I'm reiterating it for the masses).  The tilt of the earth can 
change as well.  He did not say if the tilt and/or the orbit of the 
moon could be changed enough to affect life on earth.  He did say he 
doubted it.  He mentioned that the orbit of the moon could be changed 
by a near miss, but I didn't get to ask about how close, how large, 
and if so, how much change.  If it's happened in the past then it was 
so long ago that the orbits are stable and likely to be so forever 
without intervention.  

Michael