Cecil Moore wrote:
Jim Lux wrote:
Another problem.. there's no net charge on your coffee.. so no
radiated field when you move it back and forth.

How many free electrons in coffee? How about salt water?

pH = -log hydrogen ion concentration

the pH is about 7, so hydrogen ion concentration is 1E-7. It's
neutral, so there's an equal number of negative ions. How many of them
are free electrons is another question.


But the important thing is that there's an equal number of positive and
negative charges floating around there, so there's zero net charge. An
possible radiated field from a negatively charged electron will be
exactly matched by the opposite field from a positively charged
something else.