About an electric wave
An electric wave is the abbreviation for electromagnetic waves.?
Electromagnetic waves mean the energy by the electric field and a magnetic field.
Usage changes by the difference in frequency.
?For example,
??????? The router used for wireless LAN.
??????? The electric wave of a radio broadcast.
??????? Microwave of a microwave oven.
??????? Light.
These are all kinds of electromagnetic waves.
Although it is the microwave used as a kind of the method of wireless electric supply, it is different from the electric wave of a microwave oven.
The process in which an electric wave comes to be used
| 1888 | A scholar hertz of Germany discovers an electric wave. |
| 1895 1897 |
Marconi, the inventor of Italy, develops a radiotelegraph. A radiotelegraph is developed in Japan. |
| 1901 |
Marconi succeeds in transatlantic crossing radiotelegraphy. |
| 1912 |
An SOS signal is sent when the Titanic meets with an accident. |
| 1920 |
A radio broadcast starts in the United States. |
| 1925 | A radio broadcast begins in Japan. Television is invented in Britain. |
| 1931 | Television broadcasting starts in the United States. |
| 1941 | The United States and Britain put a radar in practical use. |
| 1953 | Television broadcasting starts in Japan. |
| 1963 | Succeeded in the satellite relay by using a communications satellite.? |
| 1963 | Service of a pager begins in Japan. |
| 1969 | Color broadcast from the moon's surface according to Apollo 11 in the United States. |
| 1987 | A cordless telephone spreads in Japan. |
| 1989 | Satellite broadcasting starts in Japan. |
| 1995 | The service start of PHS |
The inventor concerned with electric wave technical development.
Let's see inventors' achievement. Heinrich Rudolf Hertz（1857- 1894）
His name became the unit of frequency.
The hertz was a German physicist.
The electricity and magnetism which Maxwell built were further developed.
He became one of the great scholars of electricity and magnetism.
Guglielmo Marconi（1874 - 1937）
His famous achievement is invention of radiotelegraphy.
He won the Nobel Prize for physics.
He built the foundation of the technology of the radiotelegraphy used for various apparatus now.
Matsunosuke Matsushiro（1866 - 1948）
He is Matsunosuke Matsushiro who had the person who developed the radiotelegraph in Japan.He succeeded in development of the radiotelegraph in which long-distance communication is possible.
【Reference】
なるほどナットク！電波が分かる本
http://www.tele.soumu.go.jp/kids/time2/time2.htmhttp://ja.wikipedia.org/wiki/ハインリヒ・ヘルツ
http://ja.wikipedia.org/wiki/グリエルモ・マルコーニ
http://www6.plala.or.jp/guti/cemetery/PERSON/M/matsushiro_m.html