Brian Davis, age 19, of Bethlehem, Penn., for his question:
WHEN DID ELECTRONICS BEGIN?
A first electronic vacuum tube was built in 1904 by a British scientist named John Ambrose Fleming. It was a two electrode tube that could detect radio signals. The tube turned out to be much more effective than earlier magnetic or crystal detectors and gradually replaced them almost entirely. An American inventor named Lee DeForest in 1907 came up with a three electrode tube.
Electronics is a branch of science and engineering that is closely related to the science of electricity. Electronics, however, can do a lot of jobs that electricity alone can't do.
Electronics has made possible such great advances as television, radio, hi fi phonographs, radar, X rays, tape recorders and high speed computers.
Electrical experiments in the 1800s marked the start of the development of electronics. The experiments involved using a gas discharge tube. This type of tube had some of the air removed, leaving a thin mixture of gases. When a battery was connected to the tube, it glowed with bright colors.
Early tubes had metal electrical poles at each end. One electrode was called a cathode and the other an anode. The negative electrode, the cathode, gave off invisible rays that were called cathode rays.
About 1878 a British scientist named Sir William Crookes developed a special tube to study cathode rays. In 1895, a German physicist named Wilhelm Roentgen discovered that the cathode rays in a Crookes tube could produce an entirely different and unfamiliar kind of ray. He named the mysterious rays X rays.
British physicist Joseph Thompson in 1897 proved that cathode rays are made up of negatively charged particles of atoms. These particles soon came to be called electrons. The discovery of electrons led to the invention of devices that could control an electron flow, or electric signal, and put it to work.
The vacuum tube era lasted from the 1920s to the 1950s.
Peak of the vacuum tube era came in 1946 when a team of scientists at the University of Pennsylvania completed the first all electronic computer. Called ENIAC (for Electronic Numerical Integrator And Computer), the giant machine contained about 18,000 vacuum tubes and worked 1,000 times faster than the fastest nonelectronic computers then in use.
Then in 1947 a team made up of John Bardeen, Walter Brattain and William Shockley invented the transistor and a new electric age dawned.