How Data on electromagnetic waves are transmitted ?

In summary, the conversation discusses how radio waves carry data and how they are received by a radio device. The questions asked relate to the transmission and reception of data on electromagnetic waves, as well as what happens to the data at that moment. The expert provides an explanation of how radio waves are detected and how sound information is sent through amplitude or frequency modulation. It is also noted that the concept of atomic excitation is not relevant to this process. The expert recommends researching topics such as antenna, AM and FM radio, and electromagnetic radiation for a better understanding.
  • #1
dailydc
11
0
Hello every one .
We know Radio waves carrying data
When a radio device receives radio waves , It render the waves and we hear sound .

Now my questions are :
1 - How data on electromagnetic waves are transmitted ?

When a electromagnetic wave hit a atom it absorbed by the atom
like this
http://www.ers-education.org/media/2009/eposters/uploads/Externe/IMAGE_10_1251465376.jpg

Then after a short delay another photon is emitted .

2 - What happens to the data at this moment ?

3 - What's the data ? are they atoms ? are they electrons ? are they Community atoms ? or ... ?
 
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  • #2
Er.. you have a wrong idea on basic E&M, especially on antenna.

Since EM waves (photons) have oscillating E-field, I can detect such waves simply with an antenna. That's what your radio does. One can naively think of it as the oscillating E-field inducing current in an antenna. This current is the transmitted signal. What you are receiving is not due to some atomic excitation.

Zz.
 
  • #3
To find out how sound information is sent by radio, search about "amplitude modulation" or "frequency modulation", better known as AM and FM.
 
  • #4
One could almost think of an old player piano where little bumps at different places make different sounds. You could think of different amplitudes or wavelengths as changing the location of the bump on the roll.
 
  • #5
Look up antenna, AM and FM radio, electromagnetic radiation, and other similar items on wikipedia. That will explain pretty much everything about this.
 

1. How are electromagnetic waves transmitted?

Electromagnetic waves are transmitted through oscillating electric and magnetic fields. These fields are perpendicular to each other and propagate in a direction perpendicular to both fields.

2. What materials can transmit electromagnetic waves?

Most materials can transmit electromagnetic waves to some extent, but some are better at it than others. Generally, materials that are good conductors of electricity, such as metals, are better at transmitting electromagnetic waves.

3. What factors can affect the transmission of electromagnetic waves?

The transmission of electromagnetic waves can be affected by various factors, including the frequency of the wave, the distance it needs to travel, and the presence of obstacles or interference.

4. How fast do electromagnetic waves travel?

Electromagnetic waves travel at the speed of light, which is approximately 299,792,458 meters per second in a vacuum. The speed may vary slightly depending on the medium through which the wave is traveling.

5. How is information encoded in electromagnetic waves for transmission?

Information can be encoded in electromagnetic waves through variations in the amplitude, frequency, or phase of the wave. This allows for the transmission of different types of information, such as audio, video, and data.

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