The Natural Philosopher wrote:
Paul Martin wrote:
In article ,
Tim S wrote:

Seriously - yes, there is a mass increase.

I wind up my cuckoo clock. The driving weight (not the pendulum)
rises a metre. Has its mass increased due to the increase in
potential energy?


I think so, yes.

So, what's it lost then? Electrons, neutrons, whole atoms, or what?

And when it falls, it regains those electrons, neutrons or whole atoms?
Conveniently in exactly the same form as when they were lost? How's that
work then?


E=mc^2 only kicks in if the body is *radiating* away energy (eg.
light, heat radiation, gamma rays, etc.) or absorbing radiated
electromagnetic energy.

I don't think so, no.

Any release of chemical energy as either heat or electricity is
accompanied by weight loss.

And the proof of that is where exactly?