Physics: 1909

1) Marconi, Guglielmo, pronounced mahr KOH nee, goo LYEHL moh (1874-1937), was an Italian inventor who popularized wireless telegraphy, or radio. He was one of the first inventors to send telegraph signals through the air using radio waves. Telegraph signals previously had been transmitted through wires. Marconi shared the 1909 Nobel Prize in physics with Karl Ferdinand Braun of Germany, who had developed ways of increasing the range of radio transmissions.

Early life: Marconi was born on April 25, 1874, in Bologna, Italy. His father was a wealthy landowner. As a child, Guglielmo took a strong interest in science. After failing the University of Bologna entrance exam, he pursued his scientific studies on his own. Inspired by the German physicist Heinrich Hertz's work with electromagnetic waves, Marconi began experimenting with wireless telegraphy in 1894. Working in an attic on his father's estate, he transmitted signals across the room. Marconi later experimented outdoors. He found that when his transmitter and receiver were grounded (connected to earth), and when he increased the height of the antenna, he could greatly extend a signal's range.

The Italian government showed no interest in the young, unschooled inventor's work, so Marconi went to the United Kingdom. There, in 1896, he received his first patent on wireless telegraphy. Marconi founded the Wireless Telegraph and Signal Company, Ltd., in London in 1897. In 1899, he sent a wireless message across the English Channel to France, and ships began using his system.

First transatlantic signal: On Dec. 12, 1901, Marconi and his staff sent and received the first wireless transatlantic communication in history. Marconi's transmitting station sent the Morse code letter s from Poldhu, Cornwall, England, to St. John's, Canada, where Marconi received it. Ships were soon using Marconi's equipment to communicate with each other and with the shore over hundreds of miles or kilometers. Marconi's equipment helped bring rescue ships for the sinking ocean liners Republic in 1909 and Titanic in 1912, saving many lives. These accidents led to laws requiring that all large passenger ships have wireless equipment.

After 1902, Marconi devoted more of his time to managing his companies, which by 1914 dominated the wireless industry in both the United Kingdom and the United States. In 1919, Marconi's American company became part of the Radio Corporation of America (RCA).

Short-wave radio: During the 1920's, Marconi turned his attention to short waves and microwaves. The existing commercial wireless equipment used long radio waves, which required large, powerful transmitters. But short-wave stations did not need such transmitters, and they cost less to build and operate. Short waves, unlike long waves, could be used as effectively during the day as at night. Marconi and his staff perfected the beam system, which used directional antennas and reflectors. This system made short-wave radio an efficient, reliable method of communication. Marconi's team also built the first microwave telephone system in 1932.

Marconi and Tesla: While Marconi was experimenting with wireless telegraphy, other prominent inventors were also working to develop the technology. One of these inventors was Nikola Tesla, an American from Austria-Hungary. By 1898, Tesla had developed high-voltage, high-frequency equipment to send signals between his laboratory and hotel in New York City. But while Tesla ambitiously planned to use his system to transmit electric power, Marconi concentrated on the profitable market of ship-to-shore communications. Marconi died on July 26, 1937.

In 1943, the Supreme Court of the United States invalidated many of Marconi's U.S. patents for radio communications equipment. It recognized that Tesla had patented a number of key radio inventions prior to Marconi.

2) Braun, Karl Ferdinand (1850-1918), a German physicist, made important contributions to the early technology of radio. Modern television screens are descended from one of Braun's inventions. He shared the 1909 Nobel Prize for physics with the Italian radio pioneer Guglielmo Marconi.

Braun studied electricity and invented several electrical instruments. The most important of these was a type of vacuum tube called the cathode-ray oscilloscope, which he devised in 1897. Braun formed the rays in the cathode-ray tube into a fine beam that could trace out patterns on the phosphorescent face of the tube. At first, this was important as a scientific instrument for displaying and measuring oscillating voltages. Later it became the forerunner of the television picture tube and the radar screen.

In 1898, Braun began to experiment with radio, then called wireless telegraphy. He improved the design of the transmitting aerial so that signals could be broadcast much farther than the 9 miles (15 kilometers) or so that had been the previous limit. He also found ways of directing radio waves into a beam, like a searchlight beam, which further increased their range. It was for this work that he shared the 1909 Nobel Prize with Marconi.

Braun was born in the German city of Fulda. He gained his doctorate from the University of Berlin in 1872. He held appointments in many German universities, becoming principal of the Institute of Physics in Strasbourg (now France) in 1895. Braun was visiting New York City as a witness in a patent dispute when the United States entered World War I (1914-1918). He was detained as a citizen of an enemy country and was still in the United States when he died.