text: A 1920 address entitled "This and the Theory of Relativity" claimed that its only mechanical quality under Lorentz, its immobility, had been lost.
full_question: A 1920 address entitled "This and the Theory of Relativity" claimed that its only mechanical quality under Lorentz, its immobility, had been lost. The Jefferson Lab at Harvard was built without iron nails to undertake the measurements of it postulated by Maxwell. In Cleveland, an experiment to understand it tested whether two light beams interfered with each other after passing through a half-silvered mirror and bouncing back; this material was famously disproven with the null results of that 1887 experiment. For 10 points the Michelson-Morley experiment cast doubt on the existance of what hypothesized medium through which light traveled?
first_sentence: A 1920 address entitled "This and the Theory of Relativity" claimed that its only mechanical quality under Lorentz, its immobility, had been lost.