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Schrödinger's cat
Intermediate
A thought experiment about superposition at large scales.
Schrödinger's 1935 thought experiment: a cat linked to a radioactive atom would be in a superposition of alive and dead, highlighting the puzzle of applying QM to macroscopic objects.
Experiments realise "cats" with superconducting circuits and large molecules.
Decoherence explains why we never see it.
In more detail
Schrödinger's cat is a thought experiment in which a quantum superposition is linked to a macroscopic outcome. It highlights the measurement problem and why macroscopic superpositions are not observed.
Real-world uses
- It is a teaching tool for understanding measurement in quantum mechanics.
- Experiments with larger and larger superpositions test the limits of quantum behaviour.
- Schrödinger's cat is used to illustrate why superposition of large objects is hard to observe in everyday life.
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Frequently asked questions
Was a real cat used?
No, it is a thought experiment devised by Schrödinger in 1935.
Why is it important?
It shows the puzzle of how superpositions turn into definite outcomes.
Is the cat really both alive and dead?
In the thought experiment, the cat illustrates an absurd conclusion of naive superposition, which decoherence helps resolve.
Related topics in Quantum Mechanics
Dirac notation · Superposition · Measurement and collapse · Entanglement · Bell's inequalities · EPR paradox