Isolation Ward From ebony pucks to magic foil, mystical and controversial tweaks.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Isolation Ward ] [ Return to Search Results ]

---

[ Alert Moderator ]

---

RE: The Double-Slit experiment

Posted by tunenut (A) on August 19, 2015 at 15:12:19

In Reply to: The Double-Slit experiment posted by Tre' on May 20, 2015 at 21:11:43:

I noticed this topic recently, as I do not hit this forum often. I know there is a long string of acrimony below, but I wanted to attempt a clear answer.

The strange finding of quantum mechanics is that a quanta does not behave either as a particle or as a wave, but has characteristics of both. A quanta could be a photon of light or an electron, or something else small, either with or without mass.

Predicting quantum behavior involves summing over all possible paths. The double slit experiment is the most simple example, as there are only 2 paths, both of 50% probability.

Here is where it starts to get strange. A single particle in the quantum world must be visualized as taking both paths. Now of course it cannot take both paths, but the probability of both paths is seen as a real thing, a "probability wave." When you project separate particles, even minutes apart, the probability waves are seen to interfere. They create interference patterns, just as light waves interfere through a grating.

How can separate particles interfere? Well they cannot. So it is wrong to visualize an electron as a tiny particle, like a little rock. It is something else much harder to visualize, a wave of probability.

Now comes the trickiest part, and the part relevant to your question. When an observable quantity must be measured, the wave of probability is said to collapse to a single value. So for example, the position of an electron, rather than being 50% maybe in one place, and 50% maybe in another, is found to be 100% in one of the two possible locations.

This part of quantum theory, collapse of the wave function, is the most mysterious and the least understood. There are many theories, none of them particularly satisfying. Most scientists would say this occurs at the moment the particle interacts with a macroscopic detector, while others say it must reach consciousness. Who can know what happens before things reach consciousness anyway? And is a dog conscious enough? There are a lot of unanswerable questions.

I would recommend The Road to Reality by Roger Penrose in this area. It is an ambitious book, and in my opinion, not completely successful, Many of the topics he tries to cover seem to be pitched way above the level that a layman will understand without extensive background. But in this one area, I think he writes at a level most people can follow.

Now, to get back to your specific question. The probability wave is seen to collapse at the point of measuremnt. So if you measure it at the slit itself, the probabilities are gone and there is a localized particle. There can be no interference after the slit in this case. If you measure it somewhere behind the slit, interference will be seen. The quantum thing acts as a wave until the very moment of measurement.

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---