Is it possible to change a fundamental property of a particle?

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Discussion Overview

The discussion revolves around the possibility of changing a fundamental property of a particle, specifically in the context of entangled particles and their spin states. Participants explore the implications of such changes on the properties of twin or entangled particles, examining concepts of measurement and entanglement.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants inquire about what is meant by "changing a fundamental property," with specific reference to changing the spin of a particle.
  • There is a discussion about the concept of twin particles, with some participants suggesting that entangled particles can be considered twins, while others challenge this notion.
  • Participants discuss the possibility of changing the direction of spin of one particle and whether this would affect the other particle in an entangled pair.
  • One participant outlines two types of transformations that can occur on an entangled particle: irreversible measurements and reversible operations, noting the randomness of measurement outcomes.
  • There is a question about whether an irreversible measurement on one particle would result in the other particle having an opposite spin, with responses indicating that it depends on the type of entanglement.
  • Some participants mention that entanglement can be anti-correlated or correlated, depending on conservation principles, and discuss the implications of these relationships.
  • A participant asserts that the entanglement of two particles is determined at the moment of their creation, while another challenges this assertion, stating that any interaction can lead to entanglement.

Areas of Agreement / Disagreement

Participants express differing views on the nature of entangled particles and the implications of changing a particle's properties. There is no consensus on the definitions or implications of these concepts, and the discussion remains unresolved.

Contextual Notes

Participants express uncertainty regarding terminology and concepts related to entanglement and measurement, indicating a range of understanding and assumptions about the topic.

Adhruth Ganesh
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Is it possible to change a fundamental property of a particle?
If that can be done, will it's twin particle's state also be altered accordingly?
 
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What exactly do you mean by "changing a fundamental property"?
 
haushofer said:
What exactly do you mean by "changing a fundamental property"?

Something like changing the spin?
 
Adhruth Ganesh said:
it's twin particle's

What "twin particle"?
 
Adhruth Ganesh said:
Something like changing the spin?

Changing what about the spin? Its magnitude or direction?
 
PeterDonis said:
What "twin particle"?

If two entangled particles are produced, let's take one of them to be the twin of the other.

Excuse me if I didn't get the terms right. I am new to this topic and this forum
 
PeterDonis said:
Changing what about the spin? Its magnitude or direction?
Direction.
 
Adhruth Ganesh said:
If two entangled particles are produced, let's take one of them to be the twin of the other.

That's not really correct, since nothing requires the two particles to be of the same type.

Adhruth Ganesh said:
Direction.

How are you going to change the direction of spin of one of the particles? Is it something that will also affect the other particle? Or are you arranging things so the particles are far enough apart that you can just act on one of them?
 
PeterDonis said:
Or are you arranging things so the particles are far enough apart that you can just act on one of them?

Yes. That is the case.
 
  • #10
Adhruth Ganesh said:
Yes. That is the case.

In the situation you describe, there are 2 types of transformations you can do on Alice's entangled particle (one "twin").

1. An irreversible measurement. Bob's particle will now be in a state consistent with the outcome of the measurement on Alice's particle (assuming an irreversible measurement has not already been performed by Bob). Note that the actual result of Alice's measurement is RANDOM.

2. A reversible operation on Alice's particle. This will have no effect on Bob's particle.
 
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  • #11
DrChinese said:
1. An irreversible measurement. Bob's particle will now be in a state consistent with the outcome of the measurement on Alice's particle (assuming an irreversible measurement has not already been performed by Bob).

So does that mean if an irreversible measurement is made on Alice's particle and it is found to have a clockwise spin, does Bob's particle have an anti clockwise one (again, assuming an irreversible measurement has not been performed by Bob) ?
I didn't quite get what consistent means here.
 
  • #12
Adhruth Ganesh said:
So does that mean if an irreversible measurement is made on Alice's particle and it is found to have a clockwise spin, does Bob's particle have an anti clockwise one (again, assuming an irreversible measurement has not been performed by Bob) ?
I didn't quite get what consistent means here.

It depends on the type of entanglement. Much entanglement is anti-correlated (opposite values), due to conservation principles. However, there are also cases where the entanglement is correlated. And other cases where the sum of 2 values will equal a constant, which is again due to conservation.
 
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  • #13
If it is selecting whether, for example, the spin is up or down, the result is random, but in accordance with what states are possible by the fundamental Schrödinger equation.
 
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  • #14
DrChinese said:
It depends on the type of entanglement. Much entanglement is anti-correlated (opposite values), due to conservation principles. However, there are also cases where the entanglement is correlated. And other cases where the sum of 2 values will equal a constant, which is again due to conservation.

Fine. Thanks a lot.
 
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  • #15
two particle are entangle or not was decided at the moment when it was created. Such as an electron downward transition twice can create two photon with spin opposite entanglement.
 
  • #16
FX_physics said:
two particle are entangle or not was decided at the moment when it was created.
That's not correct. Generally speaking, any time particles interact, they can become entangled.
 
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