Original sentence: Electromagnetic  flow in the test circuit will sometimes cause the device to act as a compass, aligning itself with the Earth's magnetic field.Trouton-Noble experiments are notoriously difficult to control
Edited sentence: This property has made it popular with some modern-day aether theory proponents, who claim any observed rotation to be attributable to the aether.Trouton-Noble experiments are notoriously difficult to control — for example, any current flow will cause the device to act as a compass, aligning itself with the Earth's magnetic field