Hacker News new | ask | show | jobs
by Yajirobe 2623 days ago
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.
1 comments

> 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).

Obviously, I did not mean to imply that you can attach a clock on a photon. I thought this goes without saying.
> I did not mean to imply that you can attach a clock on a photon.

The issue isn't that you can't attach a clock to a photon in a practical sense. The issue is that even in principle, the concept of "the clock of a photon" is not well-defined. For it to be well-defined, there would need to be an inertial frame in which a photon was at rest. But that is impossible.