Events¶
Space-time
Colin recommends readers take a look at Appendix A, for an introduction to the basic concepts of realtivity.
At the start of chapter 2 important facts and concepts from the appendix are enumerated.
An event is a point in space-time. A place and a time, if you like.
2. Causality. Events A and B are causally related if it is possible for a signal, travelling at or below the speed of light, to pass from A to B.
3. Observers and world lines. An observer or world-line, is a path in space time with each point pre-ceding later points.
4. Relativity of space and time. Space and time are relative concepts which depend on the observer.
5. Constancy of the speed of light. The speed of light (measured in a vacuum) is the same for all observers.
6. Intertial frames and observers. Frames in which Newton’s laws hold to a first order and obervers are stationary in such frames. Inertial frames exist and to first order the geometry of an inertial fram is the same as Minkowski space.
The laws of physics are unchanged by uniform linear motion.
8. Einstein’s general equivalence principle. All systems of referenece are equivalent with respect to the formulation of the fundamental laws of physics.