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Old February 20th 09, 07:39 PM posted to sci.astro,sci.physics
Ian Parker
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Default The Mosquito as space traveller

On 20 Feb, 13:42, Jan Panteltje wrote:
On a sunny day (Fri, 20 Feb 2009 03:32:48 -0800 (PST)) it happened Ian Parker
wrote in
:

Maybe the old earth was much smaller, with
hardly any water, and some big comet hit it,
driving the continents apart, creating oceans,
increasing gravity, that killing all the huge
animals.


If the Earth was smaller gravity would be HIGHER


No, no, smaller = less mass = less gravity.
If you were thinking the same mass, compressed in a smaller volume,
then at the surface you would be heavier.

The idea I was suggesting, is that if some huge comet did hit the earth,
it would get into the core, and increase the mass, causing volcanism all over the place,
and the swelling would push the continents, the solid surface layer fragments, apart.

The resulting increase in gravity due to increased mass, would kill only the big heavy lifeforms.


The Earth was hit by another body in the Hadeam period. The Hadean is
about 4 billion BP to 4.5 billion BP. There has been no catastophe of
similar magnitude since the Mezozoic which after all was only 70
million years ago. No gravity was essentially the same in the
Mezozoic. Maybe the odd ppm different.


- Ian Parker