Heisenberg's imaginary microscope showed that it would be impossible to measure the position and velocity of a particle because observing it can change the position and momentum.(adsbygoogle = window.adsbygoogle || []).push({});

However, assuming the laws of classical physics apply to these particles, I think an experiment can be set up to measure position and momentum at the same time (with accuracy).

Imagine electrons are being fired in one direction. Photons are then fired perpendicular to the path of the electron. Eventually there will be a collision, with a known time and position. But now the direction and momentum of the electron are unknown.

Farther down the path there is another device that emits photons, but it's on the other side.

Repeat this experiment enough and eventually two collisions occur, the second one sending the electron in the same direction as it was originally going.

Now you know the time and location of the second collision.

At this point, use some one-d kinematics and you know the exact position and velocity along the path!

The attached picture should explain some. Please excuse my terrible paint skills

Of course, none of this could really work, due to Heisenberg's Uncertainty Principle. But why? From what I've read, it's purely mathematical. How can we be sure that technology won't increase to a level where it's possible to know the speed and position of a particle?

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# Measuring velocity and position of a particle

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