This is a cloud chamber that can display radioactive materials in a supersaturated alcohol vapor. Here's how I built it and what it tells you.

PCBWay: https://www.pcbway.com/?from=rclifeon
PCBWay offers PCB manufacturing, 3D printing and CNC services.

Thermoelectric coolers: https://www.electron.com/
Discount code for 10%: ELEC10

Music:
Nysno - Sandra Marteleur
The Washing Ladies - John Abbot
Occurrence - Martin Gauffin
City Phases - John Abbot