Geissler Tube, an electron tube that is used to study the behavior of gases. It was invented in the 1860's by Heinrich Geissler, a German. The tube is made of glass, with an electrode at each end. Electricity is passed through a gas under low pressure within the tube; the color of the light produced depends on the kind of gas. Geissler tubes are used in physics demonstrations in high schools and colleges. They were forerunners of neon lights.
He was born exactly 300 years after Galileo died. He has yet to be awarded a Nobel Prize, although he was awarded a guest spot on “The Simpsons.” What else do you know (or not know) about this acclaimed physicist?
So much about galaxies remains a mystery. We know what they're made of and that we live in one (the Milky Way), but we're not sure how they form and evolve.