Four points A1 (0; 0), A2 (1; 0; 0), B1 (0; 100; 0), B2 (1: 100; 0) are given. They are the corners of a long drawn rectangle. A light velocity c = 300,000,000 m/s is assumed. The axis unit is meter.
- A laser oriented along the line A1-B1 emits a light flash. It starts at point A1 at time t = 0 and arrives at the point B1 at time t = 100/c.
- If the laser moves at the constant velocity v = 0.01c in the direction of the line A1-A2 during the emission, the light flash would nevertheless have to arrive at the point B1 since the movement of the light is independent of the movement of the source .
- If the laser is permanent at point A1 and the target is at point B1 at the time of emission, but after the time t = 100/c at point B2 because it moves along the line B1-B2, the light flash miss the target. The target then has the coordinates (1; 100; 0; 100/c). The target is missed because it has moved out of the optical axis of the laser during the transit time of the light flash.
- This result must not change if the laser has also moved at the time of emission (see point 2). And it still must not change if the laser and the target have the same velocity vector: if the target moves out of the firing line, the flash will not hit even though the target is at rest relative to the source (The velocity vector of the source is no argument if light is self-propagating in space).
Is there a way out of the dilemma?