A question about Mars and Earth

[Turbine353]

Hi every one.
Just want to know, if the basic media for our communication and other radio frequencies is Air, then how come they send some transmitters to the mars and that thing, sends pictures and data, to our planet? because there is not any air between mars and earth right? what type of wave is that?

thank you

 

[DMan]

It the same wave as on earth. There are no limitations for spreading od electromagnetic waves over vacuum. As a mather of a fact vacuum does "carry" the electrical wave practicly without the longitudinal loses (atenuation) whitch acuur in atmosfere. The speed of the wave is also a bit higher than in atmosfere.

 

[A.Anand Srinivasan]

only mechanical waves need a medium for transmission... EM waves do not need a wave.... also their speed is maximum through vacuum.....

 

[Dmitrij]

When sending EM waves we usually intend first of all to deliver energy (without any losses, caused by dissipation) from leaving to destination point. Therefore the most comfortable case is when the energy passes throug vacuum, where are no any obstacles. The power stream density, which characterizes the wave, may be calculated using well-known Umov-Poiting formula (from Vector analysis)

EM wave always corresponds to electromagnetic field, which comprises both electric and magnetic fields. They both exist in vacuum. The proof is magnetic fields of Earth, Sun, Jupiter and other giant objects in our enormous Solar System.

My advice - just take any book, describing electricity, magnetism or refresh you knowledge on vector analysis

With respect,

Dmitrij

 

[nikhilele]

there is not much difference in radio waves and light waves both are electromagnetic waves only differnce is their frequency and wavelength...
as light travels from sun to earth in vacuum.. similarly radio waves can travel in vacuum as both are em waves...

 

[mulima]

light travels in a vacuum and light is part of the EM spectrum so we use em to send data in space it would be nice to think as the data being some form of light. How does the light get to earth? And as i read earlier on , there is little interference in space so we should even expect the data transmission to be even more efficient.