Consider two atomic clocks, one at the GPS ground control station near Colorado Springs (elevation 1830 m) and the other one in orbit in a GPS satellite (altitude 20200 km). According to the general theory of relativity, which atomic clock runs slower? a. The orbiting clock alternately runs slow and then fast depending on where the Sun is.
b. The clock in orbit runs slow. The clock in Colorado runs slow.
c. The orbiting clock is 95% slower than the clock in Colorado.
d. The clocks keep identical time.