How is all this information transmitted by the electromagnetic field?

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Tareq - 30 Mar 2006 09:37 GMT

A simple look at the field of a uniformly moving electric charge ( see
for example
http://www.its.caltech.edu/~phys1/java/phys1/MovingCharge/MovingCharge.html
[the linear mode] ) and the striking fact that the field is always
emanating from the current position of the charge (not a retarded
position) implies that several pieces of information are transmitted
along with the elecrtomagnetic field ( at the speed f light).
1- The magnitude of the charge (1 component)
2- The current position of the charge (3 )
3-The velocity of the charge (magnitude and direction) (3)

These are seven components (degrees of freedom ) that are transmitted
simultaneously. Maybe some of them are combined into a single piece of
information.
Does any of the current theories( i.e, QED and its virtual photons)
show how this information is transmitted simultaneously?

--
Give your soul a chance to breathe
www.sultan.org

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Sue... - 30 Mar 2006 10:19 GMT

> A simple look at the field of a uniformly moving electric charge ( see
> for example
[quoted text clipped - 12 lines]
> Does any of the current theories( i.e, QED and its virtual photons)
> show how this information is transmitted simultaneously?

Abstract models have to convey their assumptions. No mechanism
is required when the conveyance exists only on paper. If we
*assume* virtual particle pairs are our mechanism, (they are not!)
we must also equip our photons with wrist-watches and magnetic
monopoles.
http://www.physics.yorku.ca/undergrad_programme/highsch/Feynm4.html

The most realistic visualization is achieved through this
study:

---Time-independent Maxwell equations---
Introduction
Coulomb's law
The electric scalar potential
Gauss' law
Poisson's equation
Ampère's experiments
The Lorentz force
Ampère's law
Magnetic monopoles?
Ampère's circuital law
Helmholtz's theorem
The magnetic vector potential
The Biot-Savart law
Electrostatics and magnetostatics

---Time-dependent Maxwell's equations---
Introduction
Faraday's law
Electric scalar potential?
Gauge transformations
The displacement current
Potential formulation
Electromagnetic waves
Green's functions
Retarded potentials
Advanced potentials?
Retarded fields
Summary
http://farside.ph.utexas.edu/teaching/em/lectures/lectures.html
http://web.mit.edu/8.02t/www/802TEAL3D/teal_tour.htm

It is not a small undertaking but the insight is rewarding.

The virtual particle pairs of QED turn out to be a very effective
*quantitative* model. To expand the model qualitativly the
real absurbdities have to be removed. If you can't find a place
to buy wrist watches and magnetic monopoles for your photons,
then you have to learn Maxwell's equations. ;-)

Sue...

> --
> Give your soul a chance to breathe
> www.sultan.org

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Ben Rudiak-Gould - 30 Mar 2006 15:44 GMT

> A simple look at the field of a uniformly moving electric charge ( see
> for example
[quoted text clipped - 10 lines]
> simultaneously. Maybe some of them are combined into a single piece of
> information.

There are infinitely many degrees of freedom in the electromagnetic field
near a point, so there's no problem encoding all that information. You can't
determine all that information from the field at a point.

-- Ben

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Natural Science Forum / Physics / Relativity / March 2006

How is all this information transmitted by the electromagnetic field?