The original post: /r/askscience by /u/CanadaNinja on 2025-01-21 16:32:23.

From my understanding, the emission spectrum is from atoms that are excited from other ways (like heat or electricity) release energy in certain wavelengths to reduce energy, and absorption is where they absorb photons to increase in energy levels. I’ve seen a few images where there are more lines in the absorption spectrum compared to the emission spectrum. Shouldn’t the wavelengths be the same for both (just inverted) since its changing between the same energy levels, just different directions? or is there additional mechanics that I don’t understand?