A-Level Turning Points in Physics - The Michelson-Morley experiment (PowerPoint & Lesson Plan)

Excellent but we suggest to add a bit of history on the Michelson-Morley experiment:<br /> With great interest we read the Commentary ‘How gravitational waves went from a whisper to a shout’, published in Physics Today August 2016, volume 69, number 8, pages 10-11. We are thinking that one may wish to emphasize that the detection was accomplished by using one of the most groundbreaking instruments in physics: The Michelson Interferometer, developed by the first American Nobel Prize winner Albert Abraham Michelson. The interferometer is so extraordinary powerful for detecting gravitational waves--LIGO's interferometers are designed to measure a distance 1/10,000th the width of a proton! Interferometers were actually invented in the late 19th century by A.A. Michelson. The Michelson Interferometer was used in 1881 in the so-called &quot;Potsdam Michelson Experiment&quot;, which set out to prove or disprove the existence of a &quot;Luminiferous Aether&quot;--a substance at the time thought to permeate the Universe. All modern interferometers have evolved from this first one since it demonstrated how the properties of light can be used to make the tiniest of measurements. The invention of lasers has enabled interferometers to make the smallest conceivable measurements, like those required by LIGO. Interestingly, the basic structure of LIGO's interferometers differs little from the interferometer that Michelson designed over 135 years ago.<br /> We would like to make the readers of this article aware of some new insights into the history of the Michelson Interferometer as published recently as contained in the papers available at <br /> https://aip.scitation.org/doi/abs/10.1063/1.37840 and <br /> http://leibnizsozietaet.de/wp-content/uploads/2016/03/HJH_BH2016_Michelson-Experiment-002.pdf<br />