... moments later, in a future world when your car has already passed the square flag, 'photon at the cabin' is part of your world.
Events happening simultaneously for you ('car at square flag' and 'photon at cabin') do not happen simultaneously for Tom (first 'car at square flag', and some time later 'photon at cabin').
Events happening 'before/after' each other for Tom (different worlds), happen at the same time for you (one world only)!
This is Einstein's RELATIVITY OF SIMULTANEITY.
As long as there is a relative speed between two systems, different worlds of simultaneous events applies. Whether it is between a landscape and a motorcycle, or a car and a train, or walking men, or two rockets in space: relativity of simultaneity occurs!
=> Go to ....
- Relativity for Dummies
- 4D Spacetime Block Universe
- Reciprocal time dilation
- Reciprocal length contraction
- Lengths do not 'appear' contracted!
- Measuring the contracted train
- Constant light speed
- Where is the bullet?
- Train experiment
- Slower and shorter - case study
- Minkowski vs Loedel
- Spacetime video
- Further reading