What did Ra mean by...?

[Learner]

Is "power upon power" some sort of expression then in English language? I googled it but got nothing.

I agree with Moyal and others who see "power upon power" as an indication the need being exponentially more. Power here didn't mean the need for power, but the mathematical meaning of power as Moyal explained. Since Ra had talked about the law of doubling: if two person have the same desire, the strength of that desire is doubled, so if n persons have the same desire, the desire is 2^n (2 to the nth power) stronger; if another m persons join in, then the strength is increased to 2^n*2^m. So "power upon power" is not an English expression per se, but it makes perfect sense here (literally as x-th power upon x-th power). I think it'd make perfect sense to Don for he was a scientist. It maybe more confusing to someone who is not well endowed in mathematics.