## Michelson and Chicago

His work with Morley exhausted him and he literally had an emotional breakdown that required hospitalization. As I noted, his loving wife actually sought to have him committed (which, imagine that, created considerable tension to their relationship) and he spent months recovering in a New York institution with serious emotional and mental incapacitation. Case actually replaced him on the faculty (!) as it was presumed that he'd never recover nor do science again. Fortunately, he recovered after a couple of months and returned to try to piece together his career and his marriage. The former recovered, but the latter was troubled until it ended 13 years later. Michelson moved himself into his own quarters in their large Cleveland house and by many accounts, his personality changed after these two betrayals becoming cynical about his relationships going forward. By the way, he was reinstated on the faculty...but told by the Board of Trustees that his salary would have to be cut in order to help pay for his (unnecessary) replacement.

By 1888 Michelson was unhappy at Case. There was the on-again, off-again, strange replacement of Michelson's position. Furthermore, there was a huge fire on campus in 1886 that destroyed Michelson's laboratory forcing him to move into Morley's lab and he could not get funds to rebuild his own space. The family had been through two more disasters in 1887 in Cleveland. A cook actually robbed them of their jewelry and other valuables (which were recovered in another town). And, in 1887 that maid accused Michelson of sexual assault actually leading to his arrest at home with headlines in the paper! Blackmail had been demanded and Michelson, Morley, a lawyer, and the Cleveland police actually set up a sting operation to get the perpetrator to expose her plot exonerating Michelson.

The lack of an ether would seem to pale compared to these events, but it didn't.

When a Clark University was started in Worcester, Massachusetts, in 1889 Michelson jumped at the chance to restart his program as the first Chair of Physics with finally adequate financial and technical support. In retrospect, Case had made a terrible mistake. Off they went to the New England countryside. It wasn't a match made in heaven for any of the faculty recruited to Clark. By 1892, Michelson and almost all of the Clark faculty resigned in unison because of an unbearable meddling by the university president who was on an entirely different course from the founder and financial benefactor, Jonas Clark. It was a mess. Today, Clark University is a thriving institution. But another one bearing the distinction of losing Michelson. To the new University of Chicago in 1892.

Michelson divorced and then remarried in Chicago and he and his new wife had three more children. His first wife created a wall between her and their children that Michelson was unable, or unwilling to break through and he had no contact with them for decades.

His time at Chicago was productive and pleasant. His students enjoyed him. He played tennis regularly and had a productive and well-staffed laboratory and was able to watch his new family grow up. He was in demand around the country and the world and took on new and engaging experiments with enthusiasm and his characteristic talent for precision optics. The projects he took on included:

* The measurement of the radius of a star – initially the red giant, Betelgeuse using interferometry – essentially capturing light with two telescopes and letting them interfere. In effect this increases the resolving power (or effective size) of any single telescope by a considerable factor. This is a standard technique especially in radio astronomy today.
* He was commissioned to create a standard of length to augment or replace the precious, single physical meter bar in Paris. This he did by counting wavelengths of sodium vapor light so a standard meter could be reproduced anywhere in the world.
* He continued his speed of light measurements and was engaged in a long-baseline experiment in California when he passed away.
* He created and perfected the creation of very precise diffraction gratings with an engineered instrument in the basement of the physics building. They were the best in the world and required weeks of patient, delicate fabrication.

Oh. And he won the Nobel Prize in 1907, the first American to do so. The prize was not for the ether experiment, as Special Relativity was still only a year or so old and Einstein was still unknown. Michelson's award reads: "for his optical precision instruments and the spectroscopic and metrological investigations carried out with their aid."

Michelson died at the age of 79 in Pasadena, California where he was engaged in a multiple experiments to improve the precision of the determination of the speed of light. He and his wife had retired from the University of Chicago and moved the previous year so he could focus on the culmination of nearly a half century of steadily improving this measurement. He had had multiple operations for prostate and intestinal disease with multiple infections (before the time of antibiotics). This final experiment involved the construction of an evacuated tube about a mile  long in the mountains of Irvine Ranch near Santa Ana, California. With multiple reflections, the path length was effectively more than 5 miles. Their biggest hurdle were the tiny geophysical shifts in the mountain range. He worked right to the end, from bed, often dictating instructions and publication drafts.

Today the determination of the speed of light is exquisitely precise using lasers: but the technique is still essentially the same one that Michelson pioneered while he was in the Navy. Likewise, his original notion of measuring the size of a star using two small, but widely spaced optical receivers and letting the interfering pattern determine the angular size of the star is now the standard technique of radio astronomy for huge radio telescopes around the world. Finally, the Michelson Interferometer is a standard bench instrument in optics labs everywhere and is the principle that was deployed in the LIGO experiment that has recently discovered Gravitational Radiation and has initiated a whole new branch of astronomy by studying the collisions of neutron stars and black holes.