Question 1: Assume you have two observers, A & B, traveling directly toward each other at constant speed and each carrying a photon emitter. At the precise moment they pass each other, each emits a single photon in the perpindicular direction. If the point at which they pass each other is point C, where would the emitted photons be detected? My understanding is that photonic travel is independent of the source. However, if that is the case, then it would seem that the photons could be detected along any point on a line parallel to paths of A & B. Am I missing something? Would a detector along the perpindicular line from C see both photons? Or would the path of both photons be influenced horizontally by A & B's directional velocity at the time of emission? Question 2: I am bothered by the notion that velocity and acceleration are differentiated by our ability to "feel" acceleration. This ability is the result of an observer being comprised of more than one component. It would seem that a point particle or quanta would have no means of recognizing acceleration, whether it be a result of gravity, or any other field. Or perhaps that is not true. It is possible that a field could acheive influence by means of the wave function, essentially altering the probability distribution of its spatial existence in the direction of the field?
Hi Sleeper, This is actually very similar to a thread that was here recently. According to SR "photonic travel" is not independent of the source. What is independent is the speed of light. In other words, the magnitude of the velocity vector is independent of the source, not the components of the velocity vector. The best thing to do is to describe the worldline of the photon in one frame and simply Lorentz transform it to the other frame. I disagree with your assessment of point particles. They don't have "feelings" in the anthropomorphic sense, but they are certainly affected by acceleration. The issue isn't wether or not a particle deforms under acceleration, but wether or not we can construct a closed physics experiment that can distinguish between one state of motion and another. We can do that for acceleration, but not for velocity. -Dale
Which direction is that? In 3 dimensions any vector in a certain plane would be perpendicular to their direction of travel... Depends. Where is your detector? Not so. If you shine a flashlight at something, is the "photonic travel" independent of the source? Your setup simply isn't specific enough to be able to answer those questions uniquely. What if the photons set off in opposite directions? Remember, everything has a certain worldline through space-time... Acceleration is the velocity change as a function of time. Velocity is the space coordinate change as a function of time. Nothing whatsoever with being able to "feel" involved. No, I don't think it is.
Need a bit more info... perpendicular according to who? If the path of a photon is perpendicular to the line ABC according to A, then it won't be perpendicular according to B, or to an observer at C.
