welcome to sciforums. I have never heard that said, but if there were nothing existing for the photon to "pass by at the speed of light" in x seconds, but only the photon its self perhaps that could be said. After all time is only associated with the change of something, not anything that can be observed to pass without reference to other things. There are no "ends of the universe", so it is hard to know what is being claimed or said. As I said in post 11, the photon is not the small point like ball of energy many think of it as, it has lenght but normally less than a meter. The "sodium D" photons I measured many years ago were ~30 cm long. Although if the photon source is a very rarefied gas and if the transion probability / rate between upper and lower states is very low or slow, then the photon can be at least several meters long. Like the red and green oxygen lines of the Northern Lights are. Perhaps that red line photon is 30 meters long - I have never seen data on this but it certainly is significantly longer than the very long green line. Not because red light wavelength is greater than that of green light line. It is fact the transition rate of the red line is about three times slower than that of the green line, as I recall.