“OH! yes; I understand it all now. Electricity is the ether;” or, “Yes; it's just like everything else: electricity is a vibration.” These are the remarks one hears made by those who think that a few ...

Heinrich Hertz’s 19th-century experiments proved electricity and light were connected – and recreating them shows what a tour de force they were What is light? In the 1860s James Clerk Maxwell used ...