On 3 April 2014 14:39, <ghib...@gmail.com> wrote: > > On Thursday, April 3, 2014 1:24:28 AM UTC+1, Liz R wrote: >> >> gbhibbsa, I'm getting a bit confused here. All I said is that >> wavefunction collapse isn't an observed fact, which seems to me a fairly >> reasonable statement, because we can't observe entities like wavefunctions >> directly, and we certainly can't observe their collapse directly. Some >> people would say we can't observe *anything* directly, but under the >> normally understood meaning of "observe" it seems reasonable to say that we >> observe the images on our retinas, and hence that we can observe the dots >> on a screen, and we can also be reasonably said to be able to observe the >> pattern they make. I'm not saying anything about the MWI or Copenhagen or >> whatever here, merely that (in normal usage of "observe") we can observe >> dots on a screen, and we can't observe abstract theoretical entities like >> wavefunctions, or their collapse. >> > > I apologize for the extensive subset of my much more extensive range of > shortcomings causing up to all of that confusion. > > May I try again...this time boiling it all down to a single request? Based > on what was at the time the widely accepted proxy for the more > problematic meaning of 'observation', what was observed that gave rise in > the first place to the widely perceived, arguably urgent, need for > an Interpretation of what it meant? >
The observation described above, and shown in the pictures. The need for interpretation comes from the fact that the objects (electrons or photons, for example) involved are assumed to be far too small to be influenced by both slits in the experiment (the fact that they form localised dots on the screen also indicates that they are very small). Yet all these small objects manage to build up a global interference pattern involving the presence of both slits (a pattern that vanishes if one slit is covered). This doesn't at first seem paradoxical, because a similar phenomenon occurs when a wave in water passes through two gaps of the right size, for example. In this case there is a medium present at each point through which the waves are travelling, so the influence has something to transmit it, and the resulting effect is easily explanied. So one's first guess is likely to be that the photons or electron in the 2-slit experiment are just be interfering with each other in a similar manner ... which wouldn't be paradoxical , of course ... except for the additional fact that the intensity of the source can be turned down until only one particle is passing through the apparatus at any given time - yet even in this case, the interference pattern still appears (eventually). This situation appears in need of "urgent" explanation because the apparent smallness of the particles in relation to the size of the equipment suggests that a single electron or photon can't possibly "know" about (be influenced by) a slit which it doesn't pass through, and which is, relatively speaking, a large distance away. Assuming a photon passes through the left hand slit, say, there is no known physical mechanism available to tell it about the existence of the right hand slit. Yet it will hit the screen in a position that is (statistically) determined by what looks like interference between waves passing through both slits. Hence the paradox. > > Hopefully you're good-to-go answering the question on those terms. Or > to say what you need additional clarification about that then you would > be, that is linked to somethiing tangible for me...like a particular word > or phrase. > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
