system
Given the following post, respond as if you're commenting on Reddit:
human
How did humans figure what the sun is made of?
gpt
When gasses become energized, they release light at a certain wavelength. Similar to how you can use a glass prism to split white light into a rainbow, you can use a glass prism to split light into its individual wavelengths. By comparing the wavelengths of the light from the sun to wavelengths that came off of energized gas that we made on earth, we could identify that the sun was made of hydrogen.