Yep, this is what he saying, but this is not what photon does. Photon must perform different amount of wave cycles to reach 1 meter or 1 trillion metters. These cycles can be counted.

▲

cryptonector 4 days ago | parent [-]

> These cycles can be counted.

In a lab setting, yes, but across such distances, no. Photons don't have a cycle counter on them, so they don't keep a cycle count and can't reveal that cycle count. All we can do is measure frequency/wavelength (spectrum, really, since we're going to see lots of photons, not really onesie/twosies) and intensity, and we can use the astrophysical distance ladder to figure out roughly where the emitter must have been.

	▲	oneshtein 3 days ago \| parent [-]
		Red shift allows us to roughly calculate distance and time, so we can multiple time by frequency of light to calculate number of oscillations or cycles and then calculate loss of energy per oscillation at average.