Collection of principles of relativity

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This post is a collection of principles of relativity. There are 10 principles listed below.

1. Time feels the same for all observers
2. Nothing can move faster than the speed of light (670,616,629 miles per hour)
3. The speed of light is the same for all observers
4. Accelerating feels like a force, while moving at a steady speed does not
5. To an observer, an object moving near the speed of light appears to contract in length
6. To an observer, an object moving near the speed of light feels heavier
7. When an observer is moving near the speed of light, the rest of the universe contracts in length
8. When an observer is moving near the speed of light, the rest of the universe feels lighter
9. An object moving near the speed of light moves through time slowly
10. Massive objects cause time to go slower in the space around them

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