Charles Reilly, age 13, of Tulsa, Okla., for his question:
How were X rays invented?
Who invented the sunshine and the seasons, the flowing tides and the blowing breezes? Naturally these wonders were created when the earth was formed, long before the first human family arrived and noticed them. Our remote ancestors learned how to cope with fire and other natural energies. Not so long ago, electricity and several other invisible energies were discovered. One of these was X rays.
X rays are invisible cosmic energies, created along with other stupendous energies by the stars and spread throughout the vast reaches of space. Hence we cannot say that these penetrating high energies were invented by any mere mortal of the planet earth. Mankind merely discovered them and learned how to tame them for its own uses. X rays were discovered in 1895. The discoverer was Wilhelm Konrad Roentgen, a physics professor at the German University of Wurzburg.
During this period, scientists were interested in the behavior of gases exposed to electric currents. Sir William Crookes of England had devised a handy gadget to study this problem. His Crookes tube was a glass container with most of the gases removed, and merely a few remaining gas molecules inside. When this near vacuum was connected to a strong electric current, . different gases glowed with their own identifying colors. Experimenters in Englanb aiiu Germany figured that the current caused waves or particles to stream from the negative cathode to the positive anode electric plates inside the tube.
They were correct, and the energy in the Crookes tube was named cathode rays. William Roentgen went one step farther. He shielded the tube with black paper to test the penetrating power of the rays. Quite by accident, he noticed a strange effect on a nearby fluorescent screen. The screen glowed and continued to glow when the current was turned off. He also noticed a weird happening to his hand when it passed between the tube and the screen. The glowing tube shed a shadow of his hand on the screen, a shadow picture showing the solid bones inside the flesh. This was, of course, an X ray image.
Roentgen was mystified and so were his fellow scientists. He named . them with the X symbol, denoting the unknown factor in a mathematical equation. Though the nature of the penetrating rays soon was revealed, we still call them X rays. Roentgen's name is pronounced RUNT gun and in honor of the discoverer the word roentgen was used to name the basic unit of X ray energy. Though the X rays we use are produced by man made machines, they are a form of electromagnetic energy, related to light, ultraviolet and infrared, radio and other cosmic radiations. Visible light rays have wave lengths around 5,000 angstroms, about 20 million per inch. The wave lengths of average X rays measure merely one angstrom, which is about 4 billion to the inch. Their penetrating power can be dangerous. But the even shorter gamma rays of the electromagnetic spectrum can be downright deadly to living tissues.