# What is the electromagnetic spectrum used for?

Mar 24, 2018

One could give almost as many answers to this question as there are different wavelengths in the electromagnetic spectrum. I'll give a few examples.

#### Explanation:

The electromagnetic spectrum consists of electromagnetic waves of every conceivable frequency. At the very low-frequency end are radio waves, both AM and FM. These waves are in the hundreds of kilohertz and megahertz range. Obviously, we use these waves to carry radio broadcasts.

As the diagram below shows, as the frequency increases, we find other uses for the waves - television, cell phone signals (in the gigahertz range). Then come microwaves, both for cooking and for broadcasting.

Radiated heat is infrared, while visible light occupies a very narrow slice of frequencies in the ${10}^{14}$ Hz range.

This is followed by ultraviolet, the ever-present light used in the forensic shows on TV for detecting blood, etc.

X-rays for imaging purposes and gamma rays in the battle against cancer.

Hopefully that's enough!