| A | B |
|---|
| Ineritial reference frame | Not accelerating |
| Ether | The medium in which light was assumed to in |
| Relativity Principle | The laws of physics are the same in all inertial reference frames |
| Time dilation | Moving clocks run slower than when at rest |
| Length contraction | Moving objects are shorter (in the direction of motion) than the object is at rest. |
| E = mc2 | Mass and energy are related |
| Light year | Measure of distance |
| Equivalance Principle | Gravitation mass is the same as inertial mass |
| Parsec | 3.26 Light-years |
