Space-time quiz

Time always ticks at exactly the same rate everywhere.

A very massive object like the Sun can bend the path of light passing close to it.

Two identical, very precise clocks are placed at the top and bottom of a tall building. What does general relativity predict?

Why do astronauts float inside the orbiting International Space Station?

Light travels at exactly 299,792,458 m/s. How far, in kilometres, does light travel in 38 microseconds — the daily GPS clock drift? Give one decimal place.

A GPS satellite clock gains about 45 microseconds per day because gravity is weaker in orbit, and loses about 7 microseconds per day because of its speed. What is the net change, in microseconds per day?

Einstein's 1911 (Newtonian-equivalent) calculation gave a deflection of 0.875 arcseconds for starlight at the Sun's edge, while full general relativity gave 1.75 arcseconds. By what factor does the relativistic prediction exceed the Newtonian one?

Why was Mercury's orbit an important early test of general relativity?

In the 1971 Hafele–Keating experiment, relativity predicted −40 ± 23 ns (eastward) and +275 ± 21 ns (westward); the clocks recorded −59 ± 10 ns and +273 ± 7 ns. Are the results consistent with the predictions? Justify quantitatively.