Why does a the Wave Function collapse?

In summary: I am not saying that one interpretation is correct and the other is not. Both rely on the same formula, make the same predictions and experiment proves both to be true.This is true, but it is not the same thing as saying that one interpretation is correct and the other is not. Both rely on the same formula, make the same predictions and experiment proves both to be true. What I am saying is that there can only be one correct interpretation for any mathematical model or formula.
  • #1
mpolo
70
1
Why does a wave function collapse when we observe a particle? I would like to know why something that is in Super Position suddenly chooses a particular position when observed? If something is in all positions or states. How does the particle choose a particular state? What is the decision making process?
 
Physics news on Phys.org
  • #2
This is still an unknown process: Why measurement collapses the superposition. This is called the Measurement Problem. Many theories are put forth to explain it, such as the Many Worlds Theory, Decoherence, etc.

For all I know "observe" has nothing to do with humans looking. A human is not necessary to collapse the superposition. Anything can perform a measurement, be it a human, a chimp, a cat, a virus, a detector, an atom, an electron, you name it.
 
  • #3
Could we say this is the cause? Super position works by the power of influencing the course of events by using a mysterious or supernatural force? Are there any other explanations besides the Many Worlds and Decoherence?
 
Last edited:
  • #4
mpolo said:
Why does a wave function collapse when we observe a particle?

Collapse is an interpretation of QM; it is not part of the basic theory. So this question is not a question about physics, it's a question about interpretation, which cannot be resolved by experiment since all interpretations make the same predictions for all experiments.
 
  • Like
Likes mfb and vanhees71
  • #5
mpolo said:
Super position works by the power of influencing the course of events by using a mysterious or supernatural force?

Please review the PF rules on personal speculation.
 
  • Like
Likes bhobba
  • #6
I think that Decoherence is the most likely explanation but there is still the problem, that Decoherence does not claim to provide a mechanism for the actual wave function collapse; rather it puts forth a reasonable mechanism for the appearance of wavefunction collapse. So I guess I am still stuck with a mystery. So to be clear, I am asking about the interpretation or meaning of the wave function collapse?

I had to read this statement many times.
PeterDonis said:
it's a question about interpretation, which cannot be resolved by experiment since all interpretations make the same predictions for all experiments.

It seems to me that there can only be one correct Interpretation for any mathematical formula or model. Are you saying we cannot prove which interpretation is correct by experiment? That I think is what I am trying to understand here. Which is what is the actual mechanism that causes wave function collapse.
 
  • #7
mpolo said:
I think that Decoherence is the most likely explanation

Decoherence is not interpretation dependent, and yes, it is the current best explanation we have in the context of basic QM (i.e., without choosing any interpretation).

mpolo said:
there is still the problem, that Decoherence does not claim to provide a mechanism for the actual wave function collapse

That's not a problem, it's just a fact.

mpolo said:
It seems to me that there can only be one correct Interpretation for any mathematical formula or model

Then you really, really need to take the time to learn about the different interpretations of QM, so you will see concrete examples of different interpretations of the same mathematical model.

mpolo said:
Are you saying we cannot prove which interpretation is correct by experiment?

Yes, because all interpretations of QM make exactly the same predictions for all experiments. This is because all interpretations use the same mathematical model to make predictions.

mpolo said:
what is the actual mechanism that causes wave function collapse.

And I've already explained why this question doesn't have an answer.
 
  • Like
Likes bhobba
  • #9
mpolo said:
It seems to me that there can only be one correct Interpretation for any mathematical formula or model.
This cannot be correct, because a mathematical formula or model is made to describe a certain process and the variables to represent a certain quantity. An experiment or measurement is usually an example which tests the validity of the model. An interpretation is per se an attachment of meaning, which humans provide to fit their individual perception of nature. It cannot be tested, because it isn't part of the model, only part of a verbal description of this model. The model itself has no meaning, resp. interpretation beside the dependencies of quantities.
Are you saying we cannot prove which interpretation is correct by experiment?
How would you distinguish whether ##\dot{x}(t)=c## is interpreted as speed or as distance. They are two different ways to describe the formula. Mathematically it is only a straight, and physically a uniform movement. You cannot say that one interpretation is correct and the other is not. Both rely on the same formula, make the same predictions and experiment proves both to be true. I admit it is a bit of a poor example, but the mechanism of interpretation is the same. I recently counted on how many ways a derivative can "interpreted" mathematically. I've found ten different environments, all describing one formula from different perspectives.
 
  • Like
Likes bhobba

1. Why does the wave function collapse in quantum mechanics?

The collapse of the wave function is a fundamental concept in quantum mechanics and refers to the transition from a probabilistic state described by the wave function to a definite state when a measurement is made. This collapse is necessary for the observed results to be consistent with classical physics and is a consequence of the measurement process itself.

2. How does the wave function collapse occur?

The exact mechanism of wave function collapse is still a subject of debate among physicists. The most widely accepted explanation is the Copenhagen interpretation, which states that the wave function collapses randomly and instantaneously upon measurement. Other interpretations, such as the Many Worlds interpretation, propose that the collapse occurs due to the interaction between the measured system and the measuring apparatus.

3. Can the wave function collapse be predicted?

No, the collapse of the wave function is a random event and cannot be predicted with certainty. The wave function only describes the probabilities of different outcomes, and the exact outcome is determined upon measurement. This is one of the key principles of quantum mechanics, known as the uncertainty principle.

4. What happens to the wave function after collapse?

After the wave function collapses, it is no longer relevant for the measured system. The system is now in a definite state, and any further measurements will produce the same result. However, the wave function can still be used to describe the probabilities of future measurements on the same system.

5. Is the wave function collapse a real physical process?

The wave function collapse is a fundamental concept in quantum mechanics, but it is still a subject of debate whether it is a real physical process or simply a mathematical tool to describe the behavior of quantum systems. Some theories, such as pilot-wave theory, propose that the wave function collapse is a real physical process, while others, such as the Many Worlds interpretation, argue that it is a mathematical construct with no physical reality.

Similar threads

Replies
1
Views
623
Replies
59
Views
3K
Replies
23
Views
2K
Replies
8
Views
1K
Replies
32
Views
2K
Replies
20
Views
2K
  • Quantum Physics
Replies
4
Views
984
Replies
1
Views
959
Replies
2
Views
786
Replies
7
Views
1K
Back
Top