11–20 of 124 posts
Actually the mysteries are deeper. This one can't explain "Delayed Choice Quantum Erasure" experiments, which is also a double slit experiment. But the arrangement allows you to detect the path AFTER the photon has traveled through one of the slits and hit the surface. Now after the photon has hit the surface you can decide whether to detect its path or not. A delayed choice. But based on your later choice the interf…
Actually the mysteries are deeper. This one can't explain "Delayed Choice Quantum Erasure" experiments, which is also a double slit experiment. But the arrangement allows you to detect the path AFTER the photon has traveled through one of the slits and hit the surface. Now after the photon has hit the surface you can decide whether to detect its path or not. A delayed choice. But based on your later choice the interf…
How can a "thought experiment" demonstrate anything?
> What many don’t realize is that the double slit experiment (with particles), proposed by Feynman in 1963, was for decades only a thought experiment. Finally, in 2013, it was successfully performed with electrons.
Total crackpot, electron diffraction was observed in 1927 by several different groups of people[1][2] some of them who later in 1937 shared the Nobel Prize in Physics[3].
[1] http://www.nature.com/nature/journal/v119/n3007/pdf/119890a0...
When I watched a goofy layman’s explanation[1] about the double slit, it stressed the importance of the effects of observation on the behavior or nature of the electrons. When observed to see “which” slit the light passed through, they no longer created the interference pattern described by Duane’s law. And when left unobserved (at the slits) the interference pattern emerged even when shooting “one electron at a time…
When you say “if we observe the position of the electron” people think: “we put an observer who without interring in any active way and he looked at the electron to see where it is”. What QM actually means is more akin to “if we take a 200 Ton bulldozer and force the electron into one or two positions and then test which one it’s in”.
The very issue arising from Observer effects is that you cannot have the system in a single state where for instance momentum and position are both observable, and observing either means forcing the system into a state where the other is “uncertain”, that is to say that it will have a distribution of outcomes if you use a different 200ton bulldozer to observe this parameter afterwards. The uncertainty principle basically tells you that the technical requirements for a “position bulldozer” and a “momentum bulldozer” makes it fundamentally and axiomatically impossible to make a single bulldozer that carries out both “observations”.
Earlier quoted context omitted.
How can a "thought experiment" demonstrate anything?
Well, from the article on the dual-slit experiment ... > What many don’t realize is that the double slit experiment (with particles), proposed by Feynman in 1963, was for decades only a thought experiment. Finally, in 2013, it was successfully performed with electrons.
> What many don’t realize is that the double slit experiment (with particles), proposed by Feynman in 1963, was for decades only a thought experiment. Finally, in 2013, it was successfully performed with electrons. Total crackpot, electron diffraction was observed in 1927 by several different groups of people[1][2] some of them who later in 1937 shared the Nobel Prize in Physics[3]. [1] http://www.nature.com/nature/j…
I stopped reading the article at this point.
However, scattering particles off objects is only one of many experiments they can be done. For instance, one will have a hard time explaining how atoms work without using some kind of wavefunction description of the electrons. Furthermore, as other commenters have mentioned, there are more sophisticated versions of the double-slit experiment, such as the delayed-choice quantum eraser, where the "quantum weirdness" simply cannot be argued away.
Frankly, it is pretty insulting by the author to assume that physicists intentionally choose the "more complicated" explanation over the "simpler" one.
Actually the mysteries are deeper. This one can't explain "Delayed Choice Quantum Erasure" experiments, which is also a double slit experiment. But the arrangement allows you to detect the path AFTER the photon has traveled through one of the slits and hit the surface. Now after the photon has hit the surface you can decide whether to detect its path or not. A delayed choice. But based on your later choice the interf…