3 ms·
> 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,
by scottlocklin 7y ago
> 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. It’s easy to see why it took so long: the slits were 62 billionths of a meter apart.
Who is this clown? I did the two slit experiment using a CRT (aka using electrons) in undergrad experimental physics class in the late 80s, and unless I had some amazing experience, I'm pretty sure every undergraduate physics major does the same thing. The '37 Nobel in physics was awarded more or less for doing this in the 1920s after de Broglie said it would be there.
- Balgair 7y agoSeriously! We literally did it in our modern physics lab. For me that was ~2004. It's not a terrible difficult experiment to do at home. Also, 62nm is not a particularly small distance in electro-optics. You can buy polarizers and the like off Thorlabs for ~$9. This person seems to be a bit of a crank.
- kgwgk 7y agoDoing it with actual slits and standalone particles is not so easy: https://www.sciencedirect.com/science/article/abs/pii/S0304399112000599 https://www.sciencedirect.com/science/article/abs/pii/S03043...
- scottlocklin 7y agoDoing the two slit experiment with electrons and actual slits is absolutely trivial, and that link doesn't say what you think it means.
- kgwgk 7y ago“The general perception is that the electron double-slit experiment has already been performed. This is true in the sense that Jönsson demonstrated diffraction from single, double, and multiple (up to five) micro-slits [2], but he could not observe single particle diffraction, nor close individual slits. In two separate landmark experiments, individual electron detection was used to produce interference patterns; however, biprisms were used instead of double-slits [3, 4]. First, Pozzi recorded the interference patterns at varying electron beam densities. Then, Tonomura recorded the positions of individual electron detection events and used them to produce the well known build-up of an interference pattern. It is interesting to point out that the build up of a double-slit diffraction pattern has been called 'The most beautiful experiment in physics' [5, 6], while the build-up for a true double-slit has, up to now, never been reported.” https://iopscience.iop.org/article/10.1088/1367-2630/15/3/033018/meta https://iopscience.iop.org/article/10.1088/1367-2630/15/3/03...
- scottlocklin 7y agoI did the experiment in 1989, closing individual slits and everything. There are entire fields of material science based on photo electron interference (ARPES, XPS and other photo emission spectroscopies). Quoting some clown who claims "well you never did it my (irrelevant) way" is not useful here.
- kgwgk 7y agoIf you think that citing a paper by a physics professor in a peer-reviewed physics journal is “quoting some clown” you’ll probably understand that I don’t give much weight to a comment from a random person on HN.
- scottlocklin 7y agoYou're perfectly free to believe in ghosts, the flat earth or DMT elves as well. People who know what they're talking about are still going to laugh at you. Do you think clowns who publish physics papers (and yes, those guys are grade-A quacks for writing that paper with such claims) are immune to the temptations of PR balognia? Do you really think "Ultramicroscopy" is a reputable physics journal? Had someone actually done something as innovative as his claims: it would be in Science, Nature and PRL. But I guess you don't actually know anything about physics and think google substitutes for knowledge and "muh links" substitute for argument.
- kgwgk 7y agoFor what it’s worth, one of the clowns who coauthored that Ultramicroscopy paper is credited with the first observation of the build-up of the interference pattern from individual electron detections in 1974 (using an electron biprism, not slits in a plate).
- scottlocklin 7y agoI'm sure their motion picture tells us all about it. PR != reality.