3 ms·

You're picking nits, I'm saying 'objects moving at C do not experience local time' and you're saying the same thing in more formal / fancy language without expl

• pdonis 5y ago
  > 'm saying 'objects moving at C do not experience local time' and you're saying the same thing No, I'm not. See below. > without explaining where exactly my statement differs from yours You evidently failed to grasp the point of my statement that the concept of "experienced time", or "proper time", is not even well-defined for lightlike worldlines. Your statement was that photons "do not experience time". And you drew from that the implication that photons cannot undergo any kind of change while propagating freely. That implication is only valid if "do not experience time" means that the concept of "experienced time" is well defined for photons, and the time that they experience is zero. However, as I explained, the concept of "experienced time" is not well defined for photons. That means you cannot draw any implications either way about whether or not photons can "change" as they propagate freely, based on the fact that the Minkowski length of their worldlines is zero. There simply is no logical implication about "change" for photons from the Minkowski length of their worldlines. To draw any conclusions about whether or not a photon can "change" as it propagates, you have to look at other things.
  • 6nf 5y ago
    > the concept of "experienced time" is not well defined for photons. how is that different from 'photons don't have experienced time'
    • pdonis 5y ago
      I explained the issue in the last two paragraphs of my post (the GP to this one). You drew an implication from "photons don't experience time" that is not valid. I explained why it's not valid.