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Quantum Wonders card QTM-34, Observers Don’t Need Eyes, with a glowing paper-cut illustration. It reads: In quantum physics, “observing” means any interaction that leaves a trace — no person or eye required.

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Observers Don’t Need Eyes

What’s going on

When physicists say a measurement changes a quantum system, they mean a detector, a stray air molecule or a single photon bumping into it — anything that carries away information about it. A particle detector in an empty room works just as well as one with a scientist watching. No mind is needed, and quantum physics gives no special power to wishing or believing.

Myth

Your thoughts change reality, so thinking hard can shape the world.

Fact

No experiment supports this.

Learn more

W. H. Zurek, Physics Today 44(10), 36 (1991).

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QTM-34 from Quantum Wonders, free quantum physics cards for ages 10 to adult

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