# Tagged Questions

48 views

### A method providing FTL communication? [closed]

I would like to see a rebuttal of my proposition of how to provide FTL communication by what I call "The Hedgehog Method". I have seen question #78460 but would not bother about entanglements nor ...
36 views

### How can the 'choice' of a photon said to be delayed?

My question arises from two ideas that seem to be contradictory. Idea One: Wheeler's Delayed Choice experiment is an interesting variation of the double slit experiment. Idea Two: In the "reference ...
52 views

### Why does the light intensity increase as I approach a distance light source?

Analogy: assume that I have constant rain fall and I have a water bucket to collect this rain. If I am rest relative to the earth, I will catch a certain amount of rain. However, if I now move towards ...
52 views

### Energy carried by photon not conserved?

In an imaginary frame of reference traveling with a photon, the length of the path traveled is 0. If the length of the path is 0, isn't it similar to say that the photon is either at the source or at ...
79 views

### How to get the accurate relativistic momentum form for photons? [duplicate]

I have studied from Griffiths, the relativistic form of momentum is $$p = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}} m_0v$$ Now when I evaluate the momentum for photon, I just insert $v=c$ and $m_0=0$ and I ...
101 views

### Why should photons obey the rules of causality?

This may have a quick answer, but it has been on my mind so here it goes: why, if according to special relativity, do photons obey the rules of causality, if they are inherently timeless. According to ...
### Photons have no mass. So, why does $E = pc$ hold? [duplicate]
It's a somewhat theoretical question. In special relativity, The energy of a photon is given by $E = pc$. But, my argument is that, since photons have no mass, how can they have a momentum $p$? The ...