One of the nice things about reading historical papers is that it allows non-technical folks (like myself) an opportunity to see how experimental physics should be done, without all of the complicated modern technology obscuring the issues.

He set up a pair of heavy steel disks (a yard in diameter) on the same axle with a small gap between them, spun them at high speed, and sent a light beam through the gap. He hoped that the ether would be dragged along by the rapidly spinning disks, and cause a detectable interference with a light beam that hadn’t gone between the disks.

At first he saw plenty of interference, and thought he had solid evidence of ether drag. But spinning the disks the opposite direction gave the same result (which it shouldn’t have if there really was ether), and he eventually showed that it was the moving air, heat, and vibration of the apparatus affecting his interferometer.

Lodge and Faraday both kept pushing past the easy (but false) vindication, and got results that were true, regardless of their personal disappointment in the outcome. In my mind that’s the mark of a real scientist.