@pingasingming Could you share which section of ch 1 you found this formula in? Using Cmd+F, I found mention of “Rydberg” only as a unit of energy in section 1.3
Got it. The two different versions would generate the same result. It’s only a matter of what the sign will end up being. If energy is absorbed, it should be +. If energy is emitted, it should be - and it looks like Kaplan’s equation would generate these signs properly
Right. Conceivably one might be asked a question where you’re told the energy level transition and told to calculate the energy, and be presented with both the positive and negative values. As such regardless of the form, the extra section contains an explanation for how to interpret the result as a function of the situation.