Chapter 2 – Wave functions and uncertainty

Copenhagen Interpretation

We will end this chapter by looking at the summary of quantum mechanics that was defined in 1927 by Niels Bohr and Werner Heisenberg. These core principles is known as the Copenhagen Interpretation

• Superposition: particles exist in multiple states until observed
• Wave function collapse: observation collapses the wave function
• Wave-particle duality: quantum objects show wave-like or particle-like behavior depending on how they are measured.
• Indeterminism: outcomes can only be predicted probabilistically
• Complementarity: there are complementary properties that cannot be simultaneously measured (e.g. position and momentum)
• Role of observer: quantum mechanics does not describe properties independently of observation

There are variations of these foundational principles that we will get to later but this is still the most widely accepted structure for quantum mechanics