# Exploring Counterfactual Definiteness in Bohmian Mechanics and Its Variants

• B
• bluecap
In summary, according to this conversation, the support counterfactual definiteness of Bohm's theory can be maintained without contradiction with experiment, as long as Locality is discarded.

#### bluecap

In standard Bohmian Mechanics, does the pilot wave support counterfactual definiteness? How about other variants of BM, don't they? Can you mention or bring up a site that summarize all variants of BH and whether the pilot wave in each support counterfactual definiteness. Thank you.

The term 'support counterfactual definiteness (CFD)' is a bit vague. Let's interpret it as meaning that, in that theory, no contradictions with experimental results are derived by assuming CFD.

Bohm's Pilot Wave theory can allow CFD without contradicting the experimental observations from Aspect et al, because it does not assume Locality. Bell's paper assumes CFD and Locality and derived inequalities that appear to have been violated by the Aspect et al experiments. So either CFD or Locality has to be discarded.

Bohm's theory discards Locality - by allowing the hidden variables to be global, rather than local to the particles in question (the information is contained in the pilot wave) - so it can keep CFD.

andrewkirk said:
The term 'support counterfactual definiteness (CFD)' is a bit vague. Let's interpret it as meaning that, in that theory, no contradictions with experimental results are derived by assuming CFD.

Bohm's Pilot Wave theory can allow CFD without contradicting the experimental observations from Aspect et al, because it does not assume Locality. Bell's paper assumes CFD and Locality and derived inequalities that appear to have been violated by the Aspect et al experiments. So either CFD or Locality has to be discarded.

Bohm's theory discards Locality - by allowing the hidden variables to be global, rather than local to the particles in question (the information is contained in the pilot wave) - so it can keep CFD.

Supposed the quantum vacuum could act as randomizer to the pilot wave, randomizing the phases making it indeterministic.. can bohmnian mechanics become indeterministic.. I seem to read that BM is all about determinism.. but could other sources of random generators make it indeterministic?

## 1. What is counterfactual definiteness?

Counterfactual definiteness is a concept in quantum mechanics that refers to the idea that a particle possesses definite properties, even if those properties are not being measured or observed. This means that, according to this concept, a particle has a specific position and momentum at all times, even if they are not known.

## 2. What is Bohmian mechanics?

Bohmian mechanics is a theory within quantum mechanics that proposes a deterministic interpretation of quantum phenomena. It suggests that particles have definite positions and velocities, and that their behavior is guided by a pilot wave, in contrast to the probabilistic nature of other interpretations of quantum mechanics.

## 3. How does Bohmian mechanics differ from other interpretations of quantum mechanics?

Bohmian mechanics differs from other interpretations of quantum mechanics in that it is deterministic, meaning that it proposes a definite trajectory for particles. It also introduces the concept of a pilot wave, which guides the behavior of particles, in contrast to the probabilistic nature of other interpretations.

## 4. What are some variants of Bohmian mechanics?

Some variants of Bohmian mechanics include the de Broglie-Bohm theory, which was the original formulation by Louis de Broglie and David Bohm, as well as the pilot wave theory, which was further developed by John Bell. Other variants include the stochastic formulation by Edward Nelson and the modified dynamics by Sheldon Goldstein and others.

## 5. What are the implications of exploring counterfactual definiteness in Bohmian mechanics?

Exploring counterfactual definiteness in Bohmian mechanics can provide a deeper understanding of the theory and its variants, as well as shed light on the fundamental nature of quantum phenomena. It also has implications for the philosophical debate between determinism and indeterminism, as well as the role of consciousness in quantum mechanics.