Peak Warming Man said:

The Rev Dodgson said:

Michael V said:

Well outside my expertise.

Maybe more dv’s area?

Or maybe it needs experts from several areas + suitable software.

You should be able to emulate it in something like Inventor and set gravity suddenly to zero.

I suppose for a start you could do a 2D model of a slice of Earth from the surface to centre.

But you would have to vary gravity as you went down, which isn’t straightforward.