Re: A big whack that made the moon may have also created continents that move

"Mad Hamish"  wrote in message 
news:[email protected]...

On Fri, 21 Jun 2024 16:47:23 -0400, "Jim Wilkins"
<[email protected]> wrote:

>"a425couple"  wrote in message news:[email protected]...
>
>A big whack that made the moon may have also created continents that move
>
>------------------------------
>https://en.wikipedia.org/wiki/Alfred_Wegener
>
>In 1912 he presented his theory that continents drift around and were once
>assembled. After his death the Nazis picked up on and promoted it, which
>tainted the concept so much that it was buried, and only resurrected when a
>grad student independently noticed and popularized the proposal and thus
>freed it from its political stigma.
>

A big issue was also that he had absolutely no mechanism for how they
could have moved

Then somebody showed that crystals showed changing magnetic fields
that would happen if the continents had moved as well as sea floor
observations backing it up
-----------------------------------
A mechanism is easy. It had long been known that temperature increases with 
the depth in a mine.
From 1869:
https://www.scientificamerican.com/article/on-the-temperature-of-coal-mines/

If that was all people knew, linearly projecting an observed 1F rise every 
~60 feet would give the temperature of molten iron below 30 miles. 
Presumably convection cells would moderate the rate of rise below that, and 
also create horizontal drag against the solid surface. Volcanos prove that 
at least some of the rock down there is molten.

A college physics problem had us integrating the net force of gravity with 
depth, to determine the return time of a weight dropped into a vacuum well 
through Earth (of uniform density). An unexpected result of the calculus was 
that gravitational attraction is zero anywhere within a hollow shell (Dyson 
sphere), only the ball below you attracts.

https://www.reddit.com/r/askscience/comments/644elp/how_does_gravity_work_in_a_dyson_sphere/