Undergrad How does Bohmian Mechanics deal with the destruction of....

[Nickyv2423]

How does BH deal with the destruction of interference in the double slit experiment when a detector is placed at the slits? If the wave function never collapses, then shouldn't the particle still follow the path? Does the measuring device change the shape of the wave function so that it doesn't interfere with itself?

 

[PeterDonis]

You've already asked a similar question about the MWI:

https://www.physicsforums.com/threa...truction-of-interference.903069/#post-5686258

How many more QM interpretations are you going to ask about? We might as well get them all out of the way.

The general answer to questions like this is that all interpretations of QM use the same math and make the same predictions. So asking how any of them "deal with" something is based on what might be called a misconception. Different interpretations of QM are not different theories. They are just different stories that people tell in ordinary language about the same theory, QM.

The story that Bohmian Mechanics tells is that all quantum interference effects come from the pilot wave (which is its term for the wave function), but the pilot wave only "guides" the particles between measurements. Without the detectors, that means the pilot wave guides the particles all through the experiment; but if detectors are placed at the slits, that is no longer true, so the interference effects go away.

Does the measuring device change the shape of the wave function so that it doesn't interfere with itself?

The answer to this is the same as it was in the MWI thread. In Bohmian Mechanics, the wave function (pilot wave) applies to the whole system, not to individual particles. Putting detectors at the slits changes the whole system, so it changes how the wave function (pilot wave) evolves.

 

[Demystifier]

Does the measuring device change the shape of the wave function so that it doesn't interfere with itself?

Loosely speaking, yes. More precisely it is not so much its shape that is changed, but rather its phase. And it does not depend on interpretation.