Discovery of the character of an electric wave
An electric wave is a kind of electromagnetic waves. An electric wave can be transmitted in a vacuum.
Unlike a sound wave, an electric wave is not transmitted through a thing or a substance.?
Maxwell stood theory as follows about electromagnetic waves.
Electrical energy and magnetic energy exist in space.
Those energies are united and it is transmitted through space.
The experiment of the next hertz proved that his theory is right.
Important character of an electric wave.
Important character of an electric wave. The electric wave is defined as the electromagnetic waves whose wavelength is longer than infrared rays.
What has a wavelength shorter than infrared rays has the character similar to light.
The electromagnetic waves (ultraviolet rays, a gamma ray, etc.) of a wavelength shorter than infrared rays may have a bad influence on a human body.
An electric wave hardly affects a human body.
The feature which goes straight on.
An electric wave has the feature which is not affected from an obstacle shorter than the length of a wavelength.Reflection
Electric waves are the same electromagnetic waves as light.The wavelength of light is very short.
An electric wave is reflected on a rude surface.
Light isn`t reflected on a rude surface.
Dispersion
Electric waves will be scattered about, if a wavelength is shorter than an object when colliding with the small object in the air.Refraction
When light goes into water or glass out of the air, it is called refraction.As for an electric wave, a direction of movement may be bent by change of the pressure in the air, temperature, humidity, etc.
Diffraction
When it hits an obstacle, a certain electric wave has the feature which turns behind an obstacle.Interference
This is prevented by changing and sending frequency in fact.When the electric wave with same frequency collides, electric waves overlap, and the phenomenon of interference occurs.
【Reference】
電波技術協会：http://www.reea.or.jp/guide/gui02.html#03
電波のキホン-周波数帯の再割当てで注目される電波の世界-
総務省電波利用ページ：http://www.tele.soumu.go.jp/j/adm/freq/search/myuse/summary/
