Bohm v Copenhagen

 Here’s a clear side-by-side comparison of the Bohm (Pilot-Wave) interpretation and the Copenhagen interpretation of quantum mechanics.

🧠 Bohm vs Copenhagen Interpretation

Feature	Bohm Interpretation (Pilot-Wave Theory)	Copenhagen Interpretation
Main Idea	Particles have definite positions at all times, guided by a wave	Quantum systems are fundamentally probabilistic
Developed by	David Bohm (1952)	Niels Bohr and Werner Heisenberg (1920s)
Nature of Reality	Deterministic	Indeterministic
Particle Position	Always well-defined	Not defined until measured
Wavefunction	Real physical field guiding particles	Mathematical tool for calculating probabilities
Measurement	No collapse; wavefunction always evolves smoothly	Wavefunction collapses during measurement
Hidden Variables	Yes (particle positions)	No
Randomness	Apparent randomness due to unknown initial conditions	Fundamental randomness
Nonlocality	Explicitly nonlocal	Nonlocal correlations but not explicitly described
Double-Slit Experiment	Particle goes through one slit; pilot wave goes through both	Particle behaves as wave until measured

🔎 Core Difference in One Sentence

• Bohm: “Particles always have positions; the wave guides them.”
• Copenhagen: “Particles don’t have definite properties until measured.”

🧩 Determinism vs Probability

• Bohm’s theory restores determinism, similar to classical physics.
• Copenhagen accepts irreducible quantum randomness.

⚡ Bell’s Theorem Context

After John Bell proved that local hidden-variable theories cannot reproduce quantum predictions:

• Copenhagen remains consistent (it already accepts nonlocal correlations).
• Bohm survives because it is explicitly nonlocal.

🏆 Practical Difference?

In experiments, both give identical predictions.

The difference is philosophical and conceptual, not experimental (so far).

If you’d like, I can also give:

• A visual intuition explanation
• A math-level comparison
• How each explains entanglement
• Which physicists prefer which
• How Bohmian mechanics actually works mathematically

What level are you aiming for?