How It Works

This section features a series of articles on parts of physics that students (and sometimes teachers) find confusing. Hopefully they will shine a little light on the matter (and if we're lucky, maybe we'll even get some photoelectric effect going on).

Particle Tracks

Signs left by a recoiling nucleus: Alpha emission to the right causes recoil of the nucleus towards the left. A secondary decay produces another alpha particle and a second recoil

The small and fleeting traces left by subatomic particles moving through a cloud or bubble chamber can tell us a lot about things we can never see. Learn to identify the tracks and why they look like they do.

Photoelectric Effect

Shine light on a metal surface, and count the number of electrons emitted per second. Change the brightness of the light and the frequency (colour) of the light.

The photoelectric effect provided evidence for the particle nature of light at a time when all evidence pointed to light being a wave. Learn what the expected and measured results were, and why.