On Sep 28, 10:00*pm, cavelamb wrote:
There is no such thing as a rigid support.

The book on the table actually does compress the table an amount equal to it's mass.

The book does compress the table slightly but once compressed, no
moire energy is required to hold up the book.

Although I am adamant about buoyancy not requiring energy input, I
think Roger may be nearly right about buoyancy being the result of
unbalanced pressures even for a balloon floating in air. I think it
is related to transfer of momentum of air or water molecules to said
balloon being diff tween top and bottom although after a rum n coke it
aint too obvious to me.
However, consider our balloon as a ping pong ball immersed in a vat of
small lead shot. The lead shot are our water molecules. Shake said
vat to produce thermal motion and said ping pong ball rises to the top
magically.

I never did like the semantics of "imaginary forces" because even for
such so-called "imaginary forces", they can lead to work being done.
Thus the distinction is almost entirely semantics (yeah yeah, I know
frames of reference and all).