If the Big Bang Theory is valid, I would think the highest possible energy producing event took place during the first fractional second of our universe’s existence. Further it must have produced the highest possible energy photon. Is there a limitation to the shortest possible wavelength of a photon? Is there a limitation to the longest possible wavelength? As a photon travels through the universe its wavelength increases due to the red shift. Will its wavelength increase smoothly or by quantum increments? If it increases incrementally, does that imply that measurements of length increase incrementally?