Einstein Again

The city of Chicago is flat. Around it the country is flat as it stretches away in all directions—except to the East, where there is fresh water. On this surrounding prairie, there lies a town called Clearing. Here on a piece of open ground, workmen have been busy laying a great amount of twelve-inch water-mains. They are the most curious water-mains that have ever been laid. There are 72,000 linear feet of them, connected with seven tons of lead to make the joints airtight. The labor of laying them alone is said to have cost $7,500. There is no water nearby nor anybody to use water. What is more, the pipe runs approximately in a rectangle 1,800 ft. long and 1,200 ft. wide, with mirrors in the corners and a double row of pipe on one of the short sides, to provide a check on the accuracy of the work. Pumps are provided to exhaust the air from the pipes.

The purpose of this great project is experiment—experiment that deals with the Einstein theory. Chicago University, endowed by John D. Rockefeller, has had the money to obtain the best equipment, both in men and material, for experimental purposes. One of the men is the famous Physics Prof. Albert Abraham Michelson, who not so long ago measured the star, Betelgeuse, although he has other equally famous research and theories to his credit. The object of this new experiment is best explained in the words which one of the experimenting physicists used to simplify the idea of the experiment for the understanding of the press:

“The object of the experiment is to determine whether or not two beams of light, traveling in opposite directions around the rectangle, require exactly the same time to complete the circuit. The system of mirrors at the four corners of the rectangle constitutes an interferometer —which is one of the most celebrated inventions of Prof. Michelson—and will make it possible to compare the time required for the two beams of light to make the circuit.

“The comparison will be brought down to within a fraction of the time required for light to make a single vibration. This time is exceedingly minute. The unit of time used in the experiment will be about 2,000,000 times 900,000 times 256 times smaller than the second.

“An observer recording the play of light on the mirrors will be able to detect the slightest variation in the velocity of the beams through the longer and the shorter legs of the rectangle. If no difference in the time of the rival beams is perceived it will be apparent that light is not affected by the earth’s rotation; in other words, that the ether rotates with the earth.

“It is at this point that the actual bearing of the experiment on the Einstein theory of relativity enters, for, according to that theory, one beam should travel around the circuit in slightly less time than the other. Generally speaking, proof that the ether rotates with the earth will be considered as contradicting the Einstein theory.”