Recent content by TheHutch

Many thanks all for your patient replies. I am learning a lot. It does seem that the use of the word 'photon' in different senses has contributed much to my confusion. Relying on wikipedia might not be the ideal approach, but I had in mind this on Fock spaces and states (sorry the formatting...

Perhaps I can summarise my conceptualisation of all this: Light sources, especially thermal, are messy, and usually should be modelled as generating a superposition of non-interacting identical particles (photons). Fundamental quantum uncertainty gives rise to this superposition and cannot be...

Throwing another pebble in the pond... Would everyone's answers change if I said 'electron' instead of 'photon'? As I understand it, we get just the same interference effects in 'double slit' experiments using electrons. Is that just a coincidence? Maybe the effects aren't the same - has...

Thanks everyone for the speedy replies. I can see that all these different perspectives are needed in practice depending on the scale of the scenario. Just to clarify my original, loosely worded question: by 'incandescent' I was really thinking of a diffuse source where emitted photons don't...

I have been looking at various sources, especially the (now closed) thread on PF classical optics "Coherence, Young's double slit experiments." The trick to making the double slit experiment work with incandescent, as opposed to laser, light is to pass it through an initial single slit 'to make...

I think this is what I was imagining earlier, when I referred to the MWI equivalent of wave function collapse. I think I have only ever heard of entanglement working one way in time - things become entangled but then stay entangled. Is that fair? The entanglement could perhaps get diluted to...

Thanks for the tip, this should keep me quiet for a bit!

Thanks everyone for the replies, it takes a little digesting... I'm not sure I'm following the Lindblad equation, for example. But here are some follow-on observations and questions: Don't mathematical formulations that make predictions that agree with observations have a right to be called...

I am forever seeing claims that the laws of physics are symmetrical in time, so to explain the 'arrow of time' we have to resort to statistical effects - increasing entropy and so on. But isn't there one law that is manifestly not time reversible: wave function collapse, or its equivalent in...

Thanks, but can you elaborate please? I have no problem with the idea of entanglement, but in a Young's slit experiment, the position of the interference fringes is determined purely by the geometry of the apparatus, surely? This implies that for fringes to be shifted when using the same set...

For the record, I just came across a paper whose title says it all: "The ‘Delayed Choice Quantum Eraser’ Neither Erases Nor Delays" R.E. Kastner 2019 available here: https://arxiv.org/abs/1905.03137 This argues at a fundamental level that entangled photon experiments don't prove what they...

I know I'm rather late to this thread, for which I apologise, but I had the same question as Herbascious J - or to put it another way, if the delayed choice apparatus is entirely removed so the idler photons just head off into space and do not interact with anything, what is seen at the signal...