system
Given the following post, respond as if you're commenting on Reddit:
human
Do rainbows contain light frequencies that we cannot see? Are there infrared and radio waves on top of red and ultraviolet and x-rays below violet in rainbow?
gpt
You bet! In fact, this is how ultraviolet and infrared radiation were discovered! 

In 1800, William Herschel (who also discovered Uranus!) used a prism to break up sunlight and attempted to measure the temperatures of the different colors. He found that when he moved his thermometer past the red end of the spectrum he measured a much higher temperature than expected (this should have been a control). He called his discovery 'calorific rays' or 'heat rays.' Today, we call it infrared, being that it's below red in the EM spectrum.

In 1801, Johann Ritter was doing a similar experiment, using the violet end of the visible spectrum. He was exposing chemicals to light of different colors to see how it effected chemical reaction rates. By going past the violet end of the spectrum he found the greatest enhancement in the reaction rate! They were called 'chemical rays' for a time, until more advanced electromagnetic theory managed to unify sporadic discoveries like these into a unified EM spectrum.