Re: Dear Uncle Al

Posted by Uncle Al on May 17, 2002 at 15:00
(68.5.243.16)

Re: Dear Uncle Al (DA Morgan)

You have an equation that has symmetries. Symmetries create conservation laws through Noether's theorem. The mathematical model thereby creates an entity with observable properties. If it corresponds to a real world observation it becomes physics.

Dirac's electron equation had symmetric answers, plus and minus. The positron was also in there.

Let's play the game to see if gravitation is an electromagnetic force:

The source of monopole radiation is a changing monopole moment for a charge q or for a mass m. Since charge and mass are conserved, there can be neither monopole electromagnetic radiation nor monopole gravitational radiation.

The source of dipole radiation is a changing dipole moment. (Punctiliously, you need a second time derivative of the dipole moment.) For a pair of charges

d = qr + q'r'

and there's nothing special about the derivatives. For a pair of masses, the gravitational dipole moment is

d = mr + m'r'

and its time derivative is

mv + m'v' = p + p'

By conservation of momentum the second time derivative of the gravitational dipole moment is zero, and you can go to a center of momentum frame and set the first derivative to zero as well.
There is no gravitational "electric dipole" radiation.

Consider the analog of "magnetic dipole" radiation. The gravitational equivalent of the magnetic dipole moment for a pair of charges is

M = mv x r + m'v' x r'
("x" is the cross product, "mv" is the "mass current")

But M is the total angular momentum, which is also conserved. There is no gravitational "magnetic dipole" radiation.

The next moment up is quadrupole, with no relevant conservation laws, so gravitational quadrupole radiation is permitted. You can use this argument to advocate that gravity must be a tensorial (spin-2) interaction. Electromagnetism is mediated by spin-1 photons.

Phsyics is taught as it was in the 1800s. There is no insight associated with memorizing equations about inclined planes and pendulums. The entire classical curriculum should be scrapped and replaced with something realistic.

Physics itself may be in for a bit of whoop-ass,

http://ww.mazepath.com/uncleal/eotvos.htm

We just learned how to calculate geometric chirality for a crystal lattice of hundreds, possibly thousands of atoms. Update next week after the computer looses its new goodies.



Follow Ups:


Post a Followup

Name:
E-Mail:

Subject:
Comments:

[ Forum ] [ New Message ]