Bell inequality tests questions

In summary: What are the different kinds of things the Bell inequality experiment test? I know most tests are testing spins of electrons, what are the other Bell tests, what they test?The Bell inequality experiment typically tests whether pairs of particles can be entangled, which is a specific example of a broader class of phenomena known as "local realism". Other examples of local realism phenomena that have been studied in the Bell inequality experiment include the domain of particles and their states, the domain of qubits, and the domain of measurements.
  • #1
Wangf
24
0
1. Are there any tests done actually show Bell inequality is NOT violated?

2. What are the different kinds of things the Bell inequality experiment test? I know most tests are testing spins of electrons, what are the other Bell tests, what they test?
 
Physics news on Phys.org
  • #2
Wangf said:
1. Are there any tests done actually show Bell inequality is NOT violated?

2. What are the different kinds of things the Bell inequality experiment test? I know most tests are testing spins of electrons, what are the other Bell tests, what they test?

1. Not so far. A test showing any kind of entanglement should always violate some kind of Bell Inequality (or other local realistic measure) in order to prove that such has been detected. To date, all setups which theoretically should show entanglement do show entanglement.

2. There are a lot of different tests. There have been tests on electrons, photons and nuclei (ions). Most tests involve pairs of particles, but entanglement has been seen on 3, 4 and more particles.

In addition, entanglement has been seen in different pairs of non-commuting observables: spin, position/momentum and time/energy are common. Sometimes, different pairs can be entangled at the same time.
 
  • #3
You can invariably NOT-violate it using defined sets of physically separate macro-objects with at least three specifiable common yes-or-no characteristics (it's easiest with a dozen or so keys or coins or books, food containers, people in a room ... or use Venn diagrams, letters in words from blocks of text etc. etc.) but some people find that less exciting than do others.

But it reiterates the profundity of what Bell accomplished. Among everything else he actually defined, in a simple formulation, a way to measurably distinguish the domain of (seeming) local realism from the quantum world. He mathematized an ontological distinction.
 
Last edited:
  • #4
Wangf said:
1. Are there any tests done actually show Bell inequality is NOT violated?
In the narrow sense of this question - if there are some tests that violate predictions of QM entanglement? - the answer is no.
In wider sense answer is somewhat trivial - in all other cases or aspects inequalities are not violated. "The exception proves the rule" in correct sense of this idiom namely "the exception confirms the rule in cases not excepted".
 
Last edited:

Related to Bell inequality tests questions

1. What is the Bell Inequality?

The Bell Inequality, also known as Bell's Theorem, is a fundamental concept in quantum mechanics that states that no physical theory can reproduce all the predictions of quantum mechanics. This means that there are certain correlations between distant particles that cannot be explained by any local theory, and therefore, quantum mechanics is a non-local theory.

2. What is a Bell Inequality test?

A Bell Inequality test is an experimental method used to test the validity of Bell's Theorem. It involves measuring the correlations between distant particles and comparing them to the predictions of a local theory. If the results violate the Bell Inequality, then the theory is not local and supports the principles of quantum mechanics.

3. How is a Bell Inequality test performed?

A Bell Inequality test involves creating a pair of entangled particles, which are particles that are linked in a way that their properties are dependent on each other. These particles are then separated and measured, and the results are compared to the predictions of a local theory. If the results violate the Bell Inequality, it suggests that the particles are not governed by local theories.

4. What is the significance of Bell Inequality tests?

Bell Inequality tests are important because they provide evidence for the non-local nature of quantum mechanics. They confirm that particles can be entangled and that their properties are not determined by local theories. This has significant implications for our understanding of the fundamental principles of the universe, and has led to the development of technologies such as quantum computing and cryptography.

5. Are there any limitations to Bell Inequality tests?

While Bell Inequality tests have provided strong evidence for the non-local nature of quantum mechanics, they are not without limitations. Some have argued that these tests are not conclusive and that there may be other explanations for the observed correlations between entangled particles. Additionally, the tests themselves can be technically challenging, and the results may be affected by experimental errors. Therefore, while Bell Inequality tests are significant, they are not the only method used to test the validity of quantum mechanics.

Similar threads

B Videos from Big Event 2015 (Växjö): Loophole free Bell test
    • Quantum Physics
Replies
0
Views
698
A Did rotating polarizer show violations of Bell's Inequality?
    • Quantum Physics
3
Replies
71
Views
3K
A What is the Bell-like Inequality in Classical Physics?
    • Quantum Physics
Replies
6
Views
1K
A Can entanglement be detected in a single Bell pair?
    • Quantum Physics
Replies
1
Views
859
I Bell tests: Changing detector settings "just before photon arrives"
    • Quantum Physics
Replies
4
Views
223
I How to enter measurement results into Bell inequality?
    • Quantum Physics
Replies
17
Views
408
B Bell's Inequalities and the issue of non-locality
    • Quantum Physics
2
Replies
50
Views
3K
I Why are terms like "deterministic" rarely used in Bell context
    • Quantum Physics
Replies
12
Views
1K
B Quantum Nonlocality or Non Counterfactual Definiteness?
    • Quantum Physics
Replies
3
Views
862
A The experiment for testing the CHSH inequalities
    • Quantum Physics
Replies
11
Views
1K

Hot Threads

Recent Insights

Back
Top