The test charge is used to measure the electric field. The problem is that if we measured some value of the field, then the test charge is removed, what will happen? The measured field is still there? Or it will be changed or it will completely disappear?
I have heard there are a theory called "action-at-a-distance" and "absorber theory", they said when the test charge is removed, the measured field also gone! Hence, we can never measure a correct electric field? Is this true?