History of electromagnetic wave’s discovery

6,016 views
5,503 views

Published on

Perhaps the greatest theoretical achievement of physics in the 19th century was the discovery of electromagnetic waves.

Published in: Education, Technology
1 Comment
4 Likes
Statistics
Notes
No Downloads
Views
Total views
6,016
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
180
Comments
1
Likes
4
Embeds 0
No embeds

No notes for slide

History of electromagnetic wave’s discovery

  1. 1. History of electromagnetic waves
  2. 2. Perhaps the greatest theoretical achievement of physics in the 19th century was the discovery of electromagnetic waves. The first hint was an unexpected connection between electric phenomena and the velocity of light.
  3. 3. About 150 years ago, James Clerk Maxwell, an English scientist, developed a scientific theory to explain electromagnetic waves. He noticed that electrical fields and magnetic fields can couple together to form electromagnetic waves. Neither an electrical field (like the static which forms when you rub your feet on a carpet), nor a magnetic field (like the one that holds a magnet onto your refrigerator) will go anywhere by themselves. But, Maxwell discovered that a CHANGING magnetic field will induce a CHANGING electric field and vice-versa. An electromagnetic wave exists when the changing magnetic field causes a changing electric field, which then causes another changing magnetic field, and so on forever. Unlike a STATIC field, a wave cannot exist unless it is moving. Once created, an electromagnetic wave will continue on forever unless it is absorbed by matter.
  4. 4. Heinrich Hertz
  5. 5. Guglielmo Maconi After Maxwell and Hertz, the next physicist who continued with the discovery of more developed magnetic waves, was Guglielmo Marconi. The Italian physicist began his experiments when he was barely 20, building on Heinrich Hertz's discovery of radio waves in 1888. In 1895 Marconi transmitted recognizable electronic signals from his family home in Pontecchio to a vertical raised antenna more than a mile away. As radio transmission of telegraph messages and, later, spoken words became more common and popular. Marconi also had the first transatlantic Morse code transmission from England to Newfoundland through electromagnetic waves.
  6. 6. Reginald Fessenden Fessenden's most notable achievements include the first audio radio transmission in 1900, the first two way transatlantic transmission in 1906 and the first broadcast of entertainment, also in 1906. Many of these were well ahead of their time, and showed his insight, not only into the technical aspects of radio, but also the commercial elements as well.
  7. 7. Done by: Bleona Çoba

×