How are electromagnetic waves genereted? how they propagate? Why certain ones are harmful and others are not?

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How are electromagnetic waves genereted? how they propagate? Why certain ones are harmful and others are not?

In: Physics

Electromagnetic waves can be generated in many ways. The most simple thing you can do is just move an electrical charge back and forth to create waves of it’s own electrical field.

How harmful they are depends on their wavelength, as that is basically the “energy per wave package”. Certain wavelength are strong enough to kick electrons away from their atom (ionize) and this can damage molecules including our DNA molecules. Others are able to be absorbed by certain molecules heating then up in the process (thats how a microwave works by sending EM waves that water likes to absorb)

>how they propagate?

Thats a bit tougher to answer and depends on what kind of details you’re interested. In general they are a fundamental force that is carried by photons. They don’t need a medium to propagate, they just move through space at the speed of light because they can’t be faster than that.

The reason why some of them are harmful has to do with the energy of the wave. All electromagnetic waves travel at the same speed, but they don’t all carry the same amount of energy. Gamma rays, X rays, and ultraviolet rays are at the high energy end of the spectrum. The high energy waves can generally do more damage than low energy ones.