The cloud chamber is an apparatus that makes the invisible, visible. Able to reveal cosmic rays that begin their lives outside of our solar system, the device allowed scientists to see antimatter for the first time – but the best part? You can build one too, using little more than a fish tank, dry ice, and some booze. Forget the “yule log,” folks. This is way, way cooler.
The chamber works because it contains a super-saturated alcohol vapor. Just like breath coming out of your mouth in the cold air of winter, the alcohol molecules want to condense into mist as they cool. That process is jump-started when charged particles zip through the chamber. These particles (electrons, alpha particles, positons, protons, and muons) knock electrons off the alcohol molecules they interact with, forcing the vapor to condense. This forms a white streak of ionized droplets along the path of the particle.
The video above, featuring a chamber built by the team at Cloudylabs, shows more trails than what you’d detect at home because the CL team is using radioactive uranium to enhance the effect. That said, a uranium-free, DIY version can still result in some phenomenal particle-viewing. Just look at the chamber physicist Dr Brian Cox built in his BBC series, Wonders of Life:
The particles we see here are “cosmic ray” muons, the result of particles (likely protons) colliding with our atmosphere. When the particles collide, they cause a shower of less-massive particles to rain down on Earth. So, there you have it: the ghostly tracks of the great, wide forever, made visible by household items. Science, we love you.
Here’s what you’ll need to create your own cloud chamber (READ: dry ice should only be handled with gloves, and alcohol should not be handled around open flames. Always wear goggles when you science at home):
- Dry ice (broken into small chunks)
- Glass aquarium
- Propanol (aka isopropyl alcohol)
- Paper Towels
- Strong light source
- Hot water bottle
- Black felt
- Gaffer’s tape
The full instructions are available here.