How did the failure of the michelson-morley experiment change scientific theories of light?

answer:

on july 12, 1887 albert a. michelson and edward w morley made the final measurements in an experiment that inadvertently changed forever the way we view the workings of the universe. the pair hoped to prove the existence of the ether—the invisible fluid thought to permeate the universe and to serve as the medium through which light waves travel. michelson modified the interfërometer—a device that splits a single beam of light into two and then recombines the two parts into one so that their wave patterns can be examined. in this experiment, one part was positioned to travel in the same direction as the earth, the other perpendicular to it. the two scientists hoped to see in the recombined beam signs that one part had been slowed down on its journey by the invisible ether sea. to their chagrin, they found absolutely no difference. their findings upset the ether theory, though neither they nor many of their peers acknowledged it, and destroyed hopes of finding the universal constant for under-standing principles of motion. dorothy michelson livingston, michelson's daughter, describes the experiment in the master of light (university of chicago press, 1979), her biography of her father. the following is excerpted from her book.