An Etymological Dictionary of Astronomy and Astrophysics

A → thought experiment, involving an elevator, first conceived by Einstein to show the → principle of equivalence. According to this experiment, it is impossible for an observer situated inside a closed elevator to decide if the elevator is being pulled upward by a constant force or is subject to a gravitational field acting downward on a stationary elevator. Einstein used this experiment and the principle of equivalence to deduce the bending of light by the force of gravity.

Etymology (EN): → einstein; elevator, from L. elevator, agent noun from p.p. stem of elevare “to lift up, raise,” from → ex- “out” + levare “lighten, raise,” from levis “light” in weight, → lever.

Etymology (PE): Bâlâbar, → lift.