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Physics

Heisenberg's Uncertainty Principle

Quick fact

The uncertainty principle is not about the limits of our instruments—it is a built-in feature of reality. Even with perfect equipment, you can never simultaneously know a particle's exact position and momentum.

Why this is interesting

You know you can measure a car's position and speed at the same time, but did you know that for an electron, there's a fundamental limit that makes this impossible? Why does nature impose such a strange rule?