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# The electromagnetic spectrum

The Sun is constantly broadcasting information about its activity in the form of light waves. Find out why there’s more to see than what meets the eye…. Created by NOVA.

## Want to join the conversation?

• At around she explains that it takes 8 min too come to Earth. (the light) so I'm thinking that when we look at the sun, we're looking at how it looked like 8 min ago?
• yes but there are many stars light years away that there light are traveling here.
• What is another threat to earth? Does the Ozone count as one?
• Unless aliens tried to kill us all the sun is the biggest threat to earth.
• I didn't understand how all the photos emitted by the sun travel at the same speed even though they have different frequencies. Frequency is inversely proportional to Time, also Speed is inversely proportional to Time. Therefore Frequency is directly proportional to Speed.
So, if the photons have variable frequencies each, their corresponding speed must also vary accordingly. Therefore if the 'speed of light's is the speed of visible light ONLY, then radio waves should travel slower than visible light, whereas gamma waves should have a speed way higher than the speed of light.
• Frequency is not proportional to time or speed for electromagnetic waves. It is proportional to energy. Speed is constant.
• Looking at the chart of wavelengths at , it seems that if the portion of the electromagnetic spectrum our eyes receive was a bit different, we could 'see' radio waves
• It would have to be quite a bit different, but yes, theoretically possible. Using technology we are able to "see" radio waves in a way by using technology to observe it for us and "translate" it into information we can understand, like sound, videos, and so forth. An example is a car radio, it receives radio waves and turns it into sound for us to understand.
• Are the radio waves emitted by the sun identical to the radio waves used on earth to construct standard AM and FM radio that we all use? How are the radio waves emitted by the sun measured?