I'm out of town at the moment on TDY and forgot my damn textbook at home. This question is giving me a headache and I can't really find anything specific in the course modules for it online.
"Light from a source having a continuous spectrum shines on a mass of hydrogen gas. What type of spectrum would you see if you were (a) on the opposite side of the gas from the source? and (b) off to the side?"
Can anyone care to explain this to me?