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Physics/Electromagnetic waves


Age, middle age.  I have a year or two college physics.

There is something I do not understand about electromagnetic waves.

It is helpful to refer to a diagram so please see the diagram right at the top of this page

Okay, now just considering the electric field....

1.  Are the blue vertical lines vectors indicating the strength of the field along the line of propagation ( ie where you might imagine a stream of photons propagating in a straight line)

2.  Does this mean there is no electric field even a small distance from the line of propagation?

Thank you.

For both your questions, the answer is "Yes, but ONLY if we look at one photon."

The fact is that there are (for most EM radiation) an almost uncountable number of photons propagating from the source. Thus, at all points where one experiences the radiation, there will be (at some time) some E-field from that radiation.


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I can help with understanding physics that does not involve eggs. I will NOT help with academic or professional questions, which are NOT limited only to homework. Please do not waste your time by asking a question that comes out of ANY kind of academic, professional, or business matters.


Have been fascinated by physical laws ever since I learned, at age seven, that magnets work under water. My study continued through college and has not ceased even after I retired.

B.A. in Physics (with honors) from University of California at Berkeley.M.A. in Physics (with honors) from University of Texas Austin.

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