On Sat, Dec 1, 2012 at 6:00 PM, meekerdb <meeke...@verizon.net> wrote:
> >>>> Again there is nothing special about an observer in this, the >> same thing would happen if nobody looked at the film, or even if you used a >> brick wall instead of film, because the important thing is not that the >> photon makes a record (whatever that is) but simply that it is destroyed. >> >> >>> But you can do the experiment with electrons too, and the electrons >> are not destroyed. >> > > >>Good point. If electrons are used in the two-split experiment a brick > wall probably wouldn't do, you'd need a metal wall. Brick is a pretty good > insulator so you'd end up with 2 small negatively charged spots on the wall > in slightly different places; > > >How would you get two charged spots? Would each have charge -e/2? > No, if many worlds is right then the universe splits every time a electron goes through the slits, and that means there are now 2 universes and that means there are now 2 electrons and 2 Brents measuring 2 negative charges on 2 insulating walls in 2 slightly different positions. So the universes are different and do not merge and no interference is found. > The experiment was originally done with photographic film, so that each > electron ionized a silver halide atom resulting in a silver spot on the > film. > Yes. > Now it's usually down is some kind of detector that amplifies the effect > of each electron. Neither one has anything to do with destroying the > electron. > You don't need to destroy the electrons you just have to arrange things so that the effect the 2 electrons have on their universes is indistinguishable, then the 2 universes will merge back together and interference is produced. If you fire electrons at 2 slits and have sensitive detectors mounted near one slit so a record is made of which slit each of the electrons went through then the universe splits into two each time a electron is fired and it does not recombine because the 2 universes are different, one has a record of the electron going through slot X and the other has a record of it going through slot Y, and so no interference is produced on the photographic plate. But if there is no detector near a slit or no record kept of which slit it went through then the universe still splits when it goes through the 2 slits because the 2 are different, the electrons are on slightly different trajectories, but when the electrons hit the metal wall there is no longer any detectable difference between the 2 universes and so they merge back together, but there is still evidence that the electron went through slot X only and evidence it went through slot Y only and this produces the interference effect. >> the walls would not be the same and so the 2 universes would not be the >> same and so they would not merge. However if it was a metal wall the >> electrons would just join the general sea of free electrons in the metal >> and there is no way even in theory to tell one electron from another. So >> the walls would have the same charge and mass. >> > > > But in an entangled electron pair experiment (EPR type) detecting the > path of one electron destroys the interference pattern on the other leg. > Yes. > But also just absorbing one electron destroys the interference on the > other leg. > Yes, if one electron is absorbed into the electron sea of a metal and the other electron is not then obviously the 2 universes remain different and so do not recombine and so no interference is found. > To maintain the interference you have to absorb the electron at the focal > point of a lens so that you not only don't detect the which-way > information, you erase it. > I don't quite know how a lens enters into this but yes, if the which-way information is not recorded or the record erased by whatever means then the 2 universes are identical and merge and a interference pattern is seen. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
