Ether and Light

Is there such a thing as ether, as the old-school physicists assert and Einstein denies? If so, does the ether fill the universe, absolutely at rest and permeating freely through all material bodies, or does the earth, as it revolves upon its axis, drag the ether with it?

This is one of the fine points of the Einstein theory of relativity which may finally be settled by experiments undertaken last week by Professor Albert A. Michelson, head of the physics department of the University of Chicago, foremost American physicist, Nobel prize winner (1907), and Professor Henry Gordon Gale, Dean of the University of Chicago Graduate School of Science.

The tests will be conducted on the military field of the University. A tile tube two feet in diameter and a block long has been laid on the ground. If the experiment proves successful on this scale, larger apparatus will be set up in a field at least a quarter of a mile square, to make possible more accurate results. The experiments have to do with rays of light thrown through the large tube. Light is believed to consist of ether waves. When a body moves through a medium which is itself in motion (e. g., a swimmer in a flowing river), the speed of the moving body depends on whether it goes with, or against, or across the current. If the medium is still, it moves past the moving body at a measurable speed. Thus, if ether is motionless, it should be possible to measure its apparent rush past the earth by detecting differences in the velocity of light when it moves in the same direction as the revolution of the earth, or in the opposite direction. The earth's speed around the sun is 18 1/2 miles a second. The speed of light is 186,330 miles a second Thus the difference in the speed ot light as it meets the earth head-on and as it follows the earth in the same direction should be easily measurable.