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.
We hear about humidity in just about every weather report on the nightly news. There are several different ways meteorologists measure humidity, but relative humidity is the most common measurement. What is relative humidity, though? Find out in this
He built President Eisenhower an indoor golf-training machine, analyzed the Zapruder film and searched for an Egyptian pyramid's treasure chamber using cosmic rays. Aren't you dying to meet this wide-ranging scientist?