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Re[2]: Fields



Thank you all for y our comments re the possible interactivity of two like
fields. I am a bit mystified by the responses -- the following seems to
be somewhat typical:

| Sounds imprecise, but not wrong. Force fields interact in the sense
| that they are vector fields, so electric fields add like vectors at
| any given point in space. Thus, electric fields from multiple sources
| can reinforce or cancel each other at any given point in space.

Well yes, but suppose that there are three stationary electrons nearby each
other. I can calculate the electric field due to each of them, but if I
want to find the net force on electron I calculate the fields due to B &
C, add them vectorially and then treat the result as ONE field.


If you put two 1 kg masses on a scale, your measurement of mass will
give 2 kg. Because you measure the masses together and their masses
add in a simple way, this does not imply that you have no way to
identify the separate masses. You just need to do a different
measurement.

But I need to remember that the various fields do not really exist -- they
are _inventions_ -- mathematical constructs if you will -- they are not
fluids which "interact".

If they don't exist, then what is the agent that exerts a force on a
charge? Fields do exist; the presence of a field can be detected
through measurement of the field's effect on matter in its
surroundings.

Here's one for the field theory guys. Consider Thomson scattering,
the scattering of a photon off a free electron. Does not the photon
interact with the electromagnetic field of the electron? If so, then
we have fields interacting with each other.

Now, dear gurus, can we get some additional comments???


Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen