Title: Re: [fonc] s3 slides
Folks,
On
slide #42, Gezira, Shouldn't the top line be Max and not Min?
Otherwise every edge contributes at least 1 to every pixel, no matter
where it is! Or, am I grossly misunderstanding this?
On
slide #39, Maxwell's Equations, are you aware that they can be derived
from just electrostatics (F = e1*e2/(r1-r2)^2) and the Lorentz
transformation of special relativity.
"From our present vantage point, the magnetic interaction
of electric currents can be recognized as an inevitable corollary of
Coulomb's law. If the postulates of relativity are valid, if
electric charge is invariant, and if Coulomb's law holds, then the
effects we commonly call "magnetic" are bound to occur.
They will emerge as soon as we examine the electric interaction
between a moving change and other moving charges." Electricity
and Magnetism (Berkeley Physics Course - Volume 2) by Edward M.
Purcell (1965) p173
This
means that magnetism with all its funny properties is simply caused by
ordinary charges moving at relativistic speeds (often inside an
atom). The existence of a magnet is proof of special
relativity. It is also very cool to be able to have a
counter-intuitive relativistic effect that you can hold in your hand
and play with!
--Ted.
--
Ted Kaehler
http://www.squeakland.org/~ted/
(home) 3261 Montecito Drive, Las Vegas, NV 89120. voice (702)
456-7930
Puzzle: Faucets in a bathroom sink can either have long handles that
turn opposite directions, or both can turn counter-clockwise to open.
Is there any direction that a hot or cold faucet can turn and be
incorrect in both schemes? --Ted.
_______________________________________________
fonc mailing list
fonc@vpri.org
http://vpri.org/mailman/listinfo/fonc
