Recent content by nnerik

Thank you so much for asking this question! This finally cleared up the matter for me. On the other hand, it is kind of disappointing to understand how trivial the solution is, all the tantalizing mystery is gone. And it makes me wonder why so many highly educated physicists, including some well...

I see that the Youtube link I posted, which pointed carefully to a specific time in the lecture, was converted by the forum to an embedded youtube video starting at the beginning. I will try to give you the URL without making a link or an object out of it so you can go straight to the relevant...

Fair enough, which should imply that unless you are clueless, you would mean something slightly different when the particle is massless. Refer Roger Penrose's reference to the photon's perspective in the Youtube video I linked in a previous post.

But this should not prevent us from trying to understand the world from a photons perspective. If we can understand a massive particle's perspective, why not a massless particle's? It is often fruitful to try to see things from different perspectives.

Come on, guys! The spacetime interval between two events on a photon's trajectory is 0! This is not up to debate. My philosophical question is what would be the most intuitive way to understand how something can "change" along an interval that measures zero! Why can't we think of all events on a...

Not dreams, mostly from books, articles and lectures. A few accessible references: http://www.universetoday.com/111603/does-light-experience-time/ https://www.quora.com/Does-a-photon-experience-time https://medium.com/starts-with-a-bang/ask-ethan-109-how-do-photons-experience-time-94756eab8bf9...

Not really. My point is that the photon will have to "swing" n periods in zero proper time. That is an infinite "proper frequency", isn't it? This works fine in a spacetime diagram, but that is only because you are allowed to draw lines between points with zero separation! How can anything...

If a photon does not experience time, how can it change? Without change, how can it have frequency?

Thanks for the pointer, this Wikipedia article helped. See the following quote (attributed to Bjorken and Drell): "The field functions are continuous functions of continuous parameters x and t, and the changes in the fields at a point x are determined by properties of the fields infinitesimally...

When I read about string theory, I sometimes get a feeling that the pointlike nature of particles in QFT is a problem that needs to be fixed, but I have never seen an explanation of the problem. Is this correct, and if so, why? Point in case (from https://en.wikipedia.org/wiki/String_theory)...