On Thu, 18 Dec 2003 15:30:26 GMT, Gene Nygaard
wrote:

Bad example. All forces, of whatever kind, are totally irrelevant to
the weight on that driver's license.

This is definately the case with most of the women that I know.


3.4.1.2 Considerable confusion exists in the use
of the term weight as a quantity to mean either force
or mass. In commercial and everyday use, the term
weight nearly always means mass; thus, when one
speaks of a person's weight, the quantity referred to
is mass.

Oh, I don't know. Maybe it's because I live in a country using
english-based units; when someone says they weigh 170 pounds, they
mean weight, as their weight was determined by a device created to
measure weight, not mass. But that's moot anyhow; while you are
correct in that we are entangled in a difference in semantics, the
real difference is not the one that you are referring to. Peter, for
example, is referring to weight in the Newtonian sense. In this
context, weight is a force, and acceleration is proof of that force.
Peter is correct within the framework that he's talking about. I am
referring to weight in the Relativistic sense. In this context,
weight is not a force, it is part of the geometry of spacetime.
Philosophically, Relativity probably holds more weight in this
argument. The whole problem with the Newtonian perspective in this
case is "what perspective do you approach this from"; i.e., what
gravitational fields do you reference when calculating "weight". Do
you leave out the sun? Do you leave out the galaxy? Heck, the galaxy
itself is accelerating. Relativity is not bothered by these
questions. Your own point of view is the only one that matters; if
you are in freefall, if you are moving along the geodisc, you are
"weightless". If you're not, you're not.

Under this definition, the Earth itself has no weight.

-R