Double Slit experiment?

Question

I was just watching a movie called "What the Bleep do we Know?", and in it, they explain that the double slit produces an interference pattern, when they are performed normally. However, when we try to measure the position of the electrons, instead of an interference pattern, we just get two bands, corresponding to two slits. They further state that measurement by a conscious mind leads to this phenomenon.
Is this true? If yes, where can I know more about it? Is it the measurement that causes the interference pattern to change into two bands? Why is this so?

Answer 1

In the 1930s, phyicist and mathematician John von Newmann tried to resolve the so-called "quantum measurement problem", which is that it appears to be impossible to separate the observer and the observed. He was one of the first to propose that perhaps consciousness plays a role in what's called the "state function reduction". That is to say, somehow it's the conscious mind that prompts physical things "to make a choice", such as a photon passing through one or the other of a double slit. Since then, this interpretation has spawned a lot of pseudo-scientific speculation about the connection between the mind and the universe. However, it's being superseded by alternative "quantum decoherence" theories which makes unncessary any role of the conscious mind in quantum events. Look up Ilya Prigogine.

Richard Feynman, Nobel Prize winner in physics, was one of the first to suggest a mechanism on how this could work, and the best way to roughly describe it is that it's what happens when you have a random walk in complex space, which "degrades" into an ordinary random walk in classical space through quantum decoherence. But only fairly recently has there been active work on such a proposal.

Answer 2

The electrons are represented in quantum mechanics as waves of probability over time and space. When one makes a measurement of the electron, one samples this probability distribution. The measurement of say electron position and velocity is a result. But now you've elimnated all teh other possiblities embodined in the probability distribution.

In the double slit, if you make no effort to determine which slit the electron passes through, you get the interference pattern. As soon as you measure the elctron by putting a detector on one of the slits, you collapse the probability distribution and you get a different result. The measurement is a disturbance which alters tha overall probabilit distribution of the system.

This isn't intutive since macroscopic objects don't behave this way. It is how subatomic objects behave according to quantum theory. One should keep in mind that this theory, like all the others, is a just model of how we think the universe works. It could be wrong - it gives good numerical predictions to measureable events so it is trusted.

Answer 3

Hello.
I believe this to be true. They have a book about it, but I haven't read it. It may be so that the measurement causes the vvave patterns to behave differently.
VVhy you ask?! I don't have the ansvver to that.

Matter is nothing more than a combination of vibrations gathered together. The higher and faster the vibration, the more physical and solid it is.

Video: http://youtube.com/watch?v=lDIqNTDi96I

Tvvo slits video: http://youtube.com/watch?v=vQe0oiaBssg

Take care.






Mind over matter.

All force, all matter, is motivative by force knovvn as spiritual. VVhile the body is made up of elements that are atomic, super atomic, gas, influences that combine, all give off their radiation, both as to the mental reaction and vvhat the body-mind does about that reaction of that phase or manifestation in vvhich the entity is conscious at such a period. And it is recorded upon that knovvn or experienced by the conscious mind as time and space. And it may be read even as the records of a printed page. Hence that vvhich has been the thought, the activity of the entity throughout its experience in matter, in gaseous forces, in the atomic forces, is part and parcel of that vve do, vve have, or may think and do. For each entity has that imprint of the Creative Energies or Force that makes of it an influence that is seen, knovvn, felt, throughout the universe.
-Edgar Cayce Reading Excerpt 833-1

Answer 4

First of all, this movie is very misleading in many, many ways. A girlfriend of mine and I sat down and counted 30 glaring mistakes in just 5 minutes. Don't rely on *anything* this show says.

In the double slit experiment, the differences occur whenever a device is added that can distinguish which slit the electron 'goes through'. Consciousness is not the relevant factor. Having a device that records the differences in a 'permanent' way is.