Re: earth/moon relationship

Michael Lorrey (
Sun, 26 Oct 1997 21:46:34 -0500 wrote:
> In a message dated 97-10-24 04:00:59 EDT, you write:
> << Well, if we were to erroneously assume that the moon is the same size it
> always was, and that the earth has expanded due to accumulated
> meteoroidal material, then we would need to have accumulated material to
> be 750 miles deep over the entire surface. This comes out to an
> accumulation rate on average of one tenth of an ince every decade. Since
> total new soil generation on earth averages one inch per 30,000 years,
> coming from all sources, including erosion of existing rock, I find this
> figure highly specious.
> Since we know that the moon has accumulated material at a far faster
> rate than the earth, due to its higher angular velocity allowing it to
> sweep through more space than the earth while taking advantage of the
> earth's greater gravity well as an attractor of material, we can
> conclude that the only time in earth's history that the moon may fit
> into a tetrahedron large enough to fit inside the earth, is sometime far
> into the future, so long as the sun doesn't go nova first.
> > >>
> No not at all, the earth has been expanding due to matter from the inner core
> being moved into the mantle, (the inner core is 3 times as dense as the
> mantle)...(well im not sure if its the inner or outer core, or a process of
> both) which happens at a far faster rate than soil deposits on the earth or
> moon. Im referring to the study (sorry no references, Ill ask some people
> and try and find out) that concludes that if you fit the continents back
> together again into the original land mass, the only way they'll fit properly
> is if the earth was 80% of the size that it is now. And since the moon
> doesnt have a hot mantle (well, im not sure if it did back then though, it
> doesnt seem like it) it would have been approximately the same size (maybe a
> mile smaller due to the meteoric impacts you were talking about).
> danny

Danny, Danny, Danny, think first. The earth is cooler now than it was
billions of years ago, right? Its no longer molten all the way through?
So due to contraction of cooling it should be smaller, right? NOT
bigger. I also thought I had explained to you that the fact that the
existing contintents being only so much area means absolutely nothing
with regards to the size of the earth, as well as that there is no way
the earth could expand due to material from the core moving out.
Material flows in and out all the time, and the density is merely due to
the gravitationally induced pressure of the weight of all the mass in
the outer layers pushing in. By your logic, the earth should be smaller
since the outer layers have been pushing against the core for billions
of years, so they must have compacted it down more. (Y'know, like why
your cereal settles down in the box over time).

			Michael Lorrey
------------------------------------------------------------	Inventor of the Lorrey Drive
MikeySoft: Graphic Design/Animation/Publishing/Engineering
How many fnords did you see before breakfast today?