When Measurement Hides Information -Mental Model 024

The more precisely the position of a particle is determined, the less precisely its momentum can be known, and vice versa.

Example: Imagine measuring the speed of a car using light. Light is made up of photons (tiny bits of light). When you shine the light on a car, you are pushing photons onto the car. In theory, the momentum of the photons would affect the momentum of the car and change the speed. In reality, it is like a truck running into a mosquito — it has little effect.

We use light photons to measure individual particles. Unlike a car, a particle is tiny. So when the photon in used to measure the position of a particle, the momentum of the photon significantly affects the momentum of a particle. It’s like a motorbike running into a car. So when we measure the position of a particle, we cannot simultaneously measure its speed.

Wisdom: “It is better to be roughly right than precisely wrong.” ― John Maynard Keynes

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Originally published at tomchanter.blog on October 19, 2017.