Einstein and Relativity: Practice Problem Solutions

1. About 300,000 km/s. It is the same for every observer.

2. Mass and energy are equivalent. A small mass can become a large amount of energy.

3. The bending of space and time by mass. Objects follow the curves.

4. Any two of: Mercury's orbit; starlight bending in the 1919 eclipse; gravitational lenses; GPS clock corrections; gravitational waves; black hole images.

5. They are accurate enough for most situations and much simpler. Einstein's theory is needed only for very strong gravity, very high speeds or high precision.

6. Starlight passing near the Sun was bent by about the amount general relativity predicts.

7. Gravitational waves, ripples in space made by two black holes merging.