geordief Posted January 5, 2017 Share Posted January 5, 2017 If thee is a source of light ,is it reasonable to see this as an expanding sphere centred around the source ? Does this scenario still apply if there is only one proton emitted ? If so , can I see this as that there is an equal chance of this photon being detected at any point on this expanding sphere? As there is only one photon involved, does its detection at one place preclude its detection at another? So ,for example if there is an object** close to the source ,and there is only one photon it will be impossible to detect the photon anywhere else (in a different direction) which is further away? **assuming that this object absorbs or "detects" the one available photon(even if there is no observer to observe this fact) Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 For photons you are discussing probability. If there's one photon, you have the probability everywhere on the sphere but that collapses when you detect the photon. You won't detect another photons somewhere else. Energy is conserved. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 It is impossible to "aim" an individual photon? Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 It is impossible to "aim" an individual photon? No. But you were describing an isotropic source. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 (edited) No. But you were describing an isotropic source. So how would you aim it ? Would the expanding sphere be "shaped" by having nearly all the region it would normally expand into shielded with a reflective/non absorptive surface? EDIT:I have just long- windedly described a length of fibre optic cable ,haven't I? Edited January 5, 2017 by geordief Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 So how would you aim it ? Would the expanding sphere be "shaped" by having nearly all the region it would normally expand into shielded with a reflective/non absorptive surface? EDIT:I have just long- windedly described of a length of fibre optic cable ,haven't I? Or a laser or optical cavity, yes. Or even a parabolic reflector, in a less restrictive example. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 (edited) Is the expanding sphere entirely to be viewed as a mathematical/geometrical representation of the probability of the spatio-temporal location of the detected photon? That's all? Edited January 5, 2017 by geordief Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 Is the expanding sphere entirely to be viewed as a mathematical/geometrical representation of the probability of the spatio-temporal location of the detected photon? That's all? It's that and in some sense the photon is everywhere on the sphere until it's detected. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 (edited) Is it a trivial observation to say that ,if an "expected" photon/detection is not made then we know that it has been absorbed elsewhere? EDIT:I seem to have wandered into double split territory.Has any one covered the space around and between the two slits with 100% reflective coating? Does that make any difference to the experiment? (not pretending to be "up" on the double slit experiment.) Edited January 5, 2017 by geordief Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 Is it a trivial observation to say that ,if an "expected" photon/detection is not made then we know that it has been absorbed elsewhere? Your expectation of absorption (assuming 100% efficient detectors) is the ratio of the detector's and sphere's surface areas. Unless you have 100% coverage, you can't expect the photon has been absorbed somewhere else, because it could be there was nothing there to absorb it. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 (edited) Your expectation of absorption (assuming 100% efficient detectors) is the ratio of the detector's and sphere's surface areas. Unless you have 100% coverage, you can't expect the photon has been absorbed somewhere else, because it could be there was nothing there to absorb it. A 100% absorptive material does not exist -and the same applies to a 100% reflective material? And the photon/detection that was "expected" but didn't show could have gone anywhere in the universe....? Edited January 5, 2017 by geordief Link to comment Share on other sites More sharing options...
swansont Posted January 5, 2017 Share Posted January 5, 2017 A 100% absorptive material does not exist -and the same applies to a 100% reflective material? And the photon/detection that was "expected" but didn't show could have gone anywhere in the universe....? We often use ideal systems when talking about this kind of problem. The photon could be detected anywhere on the sphere that's ct away from the source. Link to comment Share on other sites More sharing options...
geordief Posted January 5, 2017 Author Share Posted January 5, 2017 Thanks,Swansont.I think that satisfies my curiosity for now Link to comment Share on other sites More sharing options...
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