Hi sysprog:What is the highest possible frequency, or shortest possible wavelength, of light? We can say mathematically that as frequency goes to 0, wavelength goes to infinity, and vice versa, but we don't know what physically is the shortest or longest possible time or distance.
I think the confusion is between (a) the absence of a limit, or (b) having a infinite value for a property. In the universe example, the size (e.g volume) is either infinite or it is a finite value (possibly changing over time). For a photon, its frequency and its wavelength are never infinite (and also never zero). Do you get the distinction?