Uncertainty Principle in Wilson Cloud Chamber Measurements

[LarryS]

An alpha-particle produced by radioactive decay leaves a visible continuous track in a Wilson Cloud Chamber. As it collides with and ionizes the molecules of the vapor, its position is constantly being “measured” by the vapor molecules. If a magnetic field is present, its track will be curved and its momentum can be determined based on the degree of curvature (less curvature = more momentum). It seems like the particle’s position and momentum are both being measured precisely at the same time. Where is the Uncertainty Principle in this scenario?

Thanks in advance.

 

[humanino]

Heisenberg inequality bound is usually far far far below the experimental resolution of such a chamber. Maybe you should use realistic numbers to check that.