If you look at energy, such as any wavelength of the EM spectrum, if we multiply the wavelength times the frequency we end up with the speed of light. Infinite wavelength energy can not be energy, since infinity times zero frequency is a mathematical discontinuity. If it existed it would be something that would not be energy in the traditional sense. It could travel still at C but have neither mass or energy value.

 

Here is some interesting logic, based on the assumption that infinite wavelength not-energy, due to the mathematical discontinuity, exists.

 

If we wanted to turn this not-energy particle back into energy, we would need to shorten its wavelength from infinity and/or increase its frequency from zero, so we can get it to multipy to C. A blueshift would allow this ,by shrinking the wavelength so that energy appears.

If the wavelength is infinite, how do you blueshift it to a finite value? You're treating limits and infinities arbitrarily and inconsistently.

Point well made and taken. I was going to use GR, but we have the event horizon of a blackhole making infinite wavelength not-energy.