Eli5: What is an “energy signature”?

Question

Eli5: What is an “energy signature”?

In: 2

Answer 1

Everything emits light. Yes, even you.

And everything emits light on different frequencies with different patterns.

So we can look at those patterns and determine a signature.

If an objects emits a lot of red, infrared, and high frequency light, that’s one signature.

If an object emits a lot of visible light and almost nothing outside of that band, that’s one signature.

When you burn chemicals, they’ll emit light on various frequencies. You can use those frequencies to determine what the chemical is. If you see multiple groups of frequencies, you can use that to determine the mix of chemicals.

Edit: left out a word.