Recent content by TheHutch

  1. TheHutch

    Undergrad Young's slits with incandescent light source

    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...
  2. TheHutch

    Undergrad Young's slits with incandescent light source

    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...
  3. TheHutch

    High School The arrow of time (again)

    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...
  4. TheHutch

    High School The arrow of time (again)

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

    High School The arrow of time (again)

    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...
  6. TheHutch

    High School The arrow of time (again)

    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...
  7. TheHutch

    Undergrad Delayed quantum eraser: turning off sensor to bring back interference

    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...
  8. TheHutch

    Undergrad Delayed quantum eraser: turning off sensor to bring back interference

    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...
  9. TheHutch

    Undergrad Delayed quantum eraser: turning off sensor to bring back interference

    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...