i'd like to know two things a) is there a theoretical upper and/or lower bound to electromagnetic frequencies in the universe? i'm thinking for an upper limit, 1/planck time? for a lower limit, i have no idea-- does heisenberg uncertainty calculate into that? i suppose it would when you consider the limited size of the universe, if the frequency is so tiny that only a part of the wave exists spans the universe at one time..? b) what are the *actual* detected or even speculated upper and lower limits for electromagnetic waves? i know there are various graphs on the internets depicting the spectrum between AM radio and gamma rays, but the upper limits range from 10^20 hertz to 10^23 hertz, and the lower limits range from 10^3 hertz to 10^6 hertz depending on the graph. and they don't give numbers with any more precision than the order of magnitude. thanks..