Science: Slow Time

One of the bizarre predictions of Einstein's General Relativity is that time runs more slowly in a strong gravitational field. The effect is slight and hard to detect but Astronomer Daniel Popper of U.C.L.A. believes that he has caught time in the act of running slow.

A result of the slowing of time: light that originates in a slow-time region appears, when observed on the earth, to have slightly longer waves than local light. Motion away from the earth has the same effect, so the speed of the body from which the light is coming must be known accurately.

Dr. Popper studied the...