Re: energy, work, heat

[Leigh Palmer <palmer@SFU.CA>]

At 5:12 AM -0700 9/3/99, John Denker wrote:

> 0) The vast majority of physicists believe that energy obeys a local
> conservation law.  That is, the change in total energy within a smallish
> volume is equal to the amount of energy transferred across the boundary of
> said volume.

When did you poll the physicists, John? This may be true, but it
is not likely true for the majority of physics professors. It is
an idea which was pretty much put to rest with the work of Einstein.

Electrical charge is locally conserved; atoms are locally conserved.
Energy is not locally conserved because, unlike atoms and charge,
energy cannot be localized. The local nonconservation of energy can
most easily be seen from an accelerated frame of reference or in a
gravitational field. Simply drop an object from shoulder height and
you will observe that its energy increases with no energy "flowing"
into it. One can save the appearances of local energy conservation
by attributing to the object a gravitational potential energy, but
of course that is a fiction. That energy term is not in any sense
localized in the falling object.

It is my guess (and hope) that the majority of physics *teachers*
know that.

Leigh