"according to the photons frame of reference, Heeck found that its lifetime would be a rather short three years; however, from our frame of reference, light would live about one billion billion (10^18) years"
Note that this article is assuming, for purposes of argument, that photons actually have mass, equal to the current upper limit for possible photon mass based on experiments. But the experiments are all consistent with the current theoretical belief that photons have zero mass; and if they have zero mass, the concept of "lifetime" for a photon (and indeed the concept of "photons frame of reference") is not even well-defined.
> If they are moving with the speed of light no time passes for photons
No, the concept of "time passing" for an object moving at the speed of light has no meaning. That's why "lifetime" has no meaning for a photon if it has zero mass.
No, because the rules of Lorenz invariant field theories mean that the infinity you’re (presumably) expecting is mapped, via the joy of hyperbolic geometry, onto the propagation speed of that field.
Or, to put it another way, the speed of light is where time dilation and length contraction run into each other and it all goes zero-divided-by-zero.
> Wouldn't c have to be infinite for "no time to pass"
You're using a different notion of "time passing". Yes, we, observing photons, certainly observe them to take a finite time to cover a finite distance. But that is not the same as the concept of "time passing" for the photons themselves, for example according to a clock that the photons carried along with them; that is the concept that has no meaning.
If the photons were a conscious subject, would that mean, from their point of view, they are everywhere (everywhere being defined as the entire path the photon will take from its genesis to its final destruction or absorption), all at once? Because if no time is passing for them, doesn't that mean no space is being traversed either?
No, outside observer will measure clocks of photon run slower by a factor of γ (Lorentz factor), which (in scalar form) is equal to 1/sqrt(1 - v^2 / c^2 ). It diverges at v = c.
> outside observer will measure clocks of photon run slower by a factor of γ
This is not correct since "clocks of photon" is a meaningless concept (at least if photons have zero mass, which they do according to our best current models).
> Speed of light is for-all-practical-purposes infinite in the reference frame of the moving object (i.e. photon), thanks to special relativity.
This is not correct, because there is no "reference frame" for a photon moving at the speed of light. The concept of "reference frame" is not well-defined for such objects.
This conversation sounds like it's running into the linguistic barrier that we tend to think of "speed of light" in terms of, well, light, so becomes recursive when talking about photons with mass, which naturally travel slower than what should be thought as "the speed of massless particles".
This according to measured upper limits on photon mass. Strong theory postulates absolute zero mass for the fundamental particle and in this case it will have an infinite lifetime.