Particle Movement in Quantum Mechanics

[topsquark]

The way we introduce Quantum Physics creates some difficulties. I see few ways around it: QFT is too complex to teach to a Junior year level student: like so many other concepts in Physics we need to start with something simpler and correct the picture later on. The picture of particles and waves has its uses (and some are rather spectacular) but isn't really what we think happens. A particle (or wave, if you like) is a fluctuation in the Quantum field that is represented by that particle (or wave.)

So does an "electron" exist between measurements? The question really doesn't make sense. The Quantum field representing the electron does. So does the Quantum field of the electron exist between measurements? Of course. It permeates all space-time. (I'm ignoring the singularity thing. I have not one clue about that sort of situation.) So there is no weird popping in an out of existence to worry about. Continuous motion? The electron field is continuous (presumably) but the particle aspect does not need to be: the question is a bit of a red herring based on a preconception in Classical Physics, where particle trajectories always are.

Better to think of fields instead of particles. It will make things a lot easier to deal with and understand.

-Dan

 

[WernerQH]

QM does not extend this logic to the particle's movement being continuous or not. Intuitively, people --and especially laymen-- cannot help wondering whether this is the case or not.

We perceive the classical world around us as composed of objects, and these objects composed of smaller objects (particles). But at the smallest scales of space and time, the concept of a particle loses its usefulness. At the smallest scales there are no particles.

In his essay "Science and Ultimate Truth", H.G.Wells wrote (1931):

It may be that we exist and cease to exist in alternations, like the minute dots in some forms of toned printing or the succession of pictures on a cinema film. It may be that consciousness is an illusion of movement in an eternal, static, multidimensional universe. We may be only a story written on a ground of inconceivable realities, the pattern of a carpet beneath the feet of the incomprehensible. We may be, as Sir James Jeans seems to suggest, part of a vast idea in the meditation of a divine circumambient mathematician.

Movement as an illusion ...

 

[Lord Jestocost]

So if I understand correctly, QM prescribes that if a particle exists in the absolute sense, it can be detected somewhere.

QM does not extend this logic to the particle's movement being continuous or not. Intuitively, people --and especially laymen-- cannot help wondering whether this is the case or not.

One should be cautious with – so to speak – interpretations. As John Marburger/1/ has put it: “We can only measure detector clicks. But when we hear the click we say “there’s an electron!” We cannot help but think of the clicks as caused by little localized pieces of stuff that we might as well call particles. This is where the particle language comes from. It does not come from the underlying stuff, but from our psychological predisposition to associate localized phenomena with particles.”

/1/J. Marburger, “On the Copenhagen interpretation of quantum mechanics,” in Symposium on The Copenhagen Interpretation: Science and History on Stage, National Museum of Natural History of the Smithsonian Institution, 2 March (2002)

 

[PeterDonis]

It is my opinion

Then it's off limits here unless you can provide a mainstream reference. Which you haven't.

 

[PeterDonis]

In his essay "Science and Ultimate Truth", H.G.Wells wrote (1931):

This is not a valid reference.

 

[PeterDonis]

The OP question has been answered and the thread is veering off into speculation. Thread closed.