[ExI] scieceblind

[Adrian Tymes]

On Fri, Oct 13, 2017 at 9:11 AM, Dan TheBookMan <danust2012 at gmail.com> wrote:
> The book is pulled down by gravity (in classical mechanics). If it's being
> acted in by a force yet doesn't move (in an inertial frame*), then another
> force must must be balanced against gravity. Since the book doesn't move,
> then it must be acted on by an equal and opposing force. In this case the
> table itself is pushing up against gravity.

To extend this: the weight of the book pushes down on the table.
Since the table pushes the book up, the table itself is pushed down
more.  Thus, the floor under the table must bear the downward force
(the "weight") of the table and the book, even though only the table
is in direct contact with the floor.  Eventually you get down to the
foundations of the house, which transmit the weight of everything in
the house to the earth underneath.

Go down far enough and the pressure, from the weight of everything
above, would crush any of us were we down there.  Fortunately, we are
not down there; all that's down there is rock and magma, which are far
more resistant to crushing than flesh and bones are.