I walk across a carpet and then touch a doorknob. A big fat spark leaps from my hand to the doorknob. The doorknob is now charged. It is also being accelerated at 9.8 m/sec^2 (like everything else on this planet). We are told that "accelerated charges radiate electromagnetic radiation". Hence the questions:
1. Does the doorknob radiate as long as it retains the charge? Why or why not? If it radiates, where is the energy coming from?
2. Is it possible to accelerate an object without having it change speed, position, or direction in space?
3. Suppose the doorknob remains stationary, but the remainder of the room moves or oscillates. Is radiation present? Does this relate to the question of absolute motion?
4. Does this question involve a "change of direction of motion" or a "change of dimension of motion"? (Motion involves TWO things: space and time. In Beyond Einstein (https://www.researchgate.net/publication/309533409_Beyond_Einstein_non-local_physics) I discuss motion with no direction, and direction with no motion. This question could involve "motionless motion". I am just trying to expand my thinking vocabulary here, and am seeking some additional insights. )
Very nice question
1) The charged doorknob radiates electromagnetic waves in the frame of reference where it is accelerating. In your frame it is not. The gravitational acceleration 9.8 m/s^2 is canceled by so called "reaction of the floor".
2) In order to accelerate something you have to, by the definition, be changing speed or direction. Acceleration is just the second derivation with respect to time. But you question is deeper that that. Since the times we have General relativity the issue complicates a bit. The acceleration can be produced by only "slowing" the clocks of the object (by gravitation). This kind of acceleration on charged objects do not produce electromagnetic waves.
3) Yes. Yes, exactly.
4) Nice article. Fine structure of vocabulary and language can crumble under the too much pressure. So the final arbiter is the experiment. Changing of the paradigm or the view on the same physical problem can be sometimes very helpful, but nothing more.
1) I disagree with the answer above to this part.
The charged door-knob is accelerating, but the acceleration is very small. Your frame of reference is a rotating and accelerating frame of reference, not an inertial one (the frame is the surface of a spinning earth). The radiation will be very small, because the acceleration is small. The energy for the radiation comes from the rotational energy of the earth, which will be constantly slowing down its rate of rotation due to the radiation.
If it was left to itself, the doorknob would not remain on the surface of the earth, but orbit round the centre of the earth and the sun in an orbit that would not keep it in its place on the door in the house. The surface of the earth pushes it (through the door-frame and the door) to keep it where it is. This force provides the necessary acceleration to keep it where it is.
3) I think the oscillation of the rest of the room would not affect the radiation of the door-knob. If the rest of the room were charged (it might be, because the charge on the door-knob will have induced a charge on it), then the rest of the room would radiate when it oscillated.
A statically charged doorknob does not radiate (electromagnetically) like any other statically charged object at rest.However there is a fast transient when the spark comes and this radiates quite abit...and then there is a very slow discharge of the (insulated) knob which theoretically radiated VERY very little.And forget about the grav field..unless the knob falls down..
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