You Don't Have to be an Evil Genius to Turn Your Smartphone Into a Cosmic Ray Detector

By Gerald Lynch on at

Physicist Justin Vandenbroucke of the University of Wisconsin-Madison has created a new app that uses a smartphone's image sensor to detect cosmic rays -- something that has in the past required multi-million pound observatory equipment to achieve.

While cosmic rays are still one of the more puzzling aspects of the universe, scientists have been able to agree on the theory that they consist of subatomic particles created by black holes and the aftermath of supernova events. These particles eventually make their way to the Earth's atmosphere, where they transform into a secondary particle known as a muon.

The Android app (which could theoretically run on any smartphone platform provided it has a camera) harnesses the "photoelectric effect", the moment that light particles (photons) hit a silicon surface and deliver an electric charge. The photoelectric effect works the same for muons, so when they hit a semiconductor within a smartphone camera, that electric release can be logged by the app.

It's not quite as simple as just side-loading the app to a phone and firing it up though -- the phone's camera lens can interfere with results, so that must be covered with duct tape first. But once that's done, so long as the screen is facing up, the app can start tracking muon activity with relative accuracy -- even if the phone is tucked away in a drawer.

While, unlike in the comic books, cosmic rays can't be used to give you superhuman powers, Vandenbroucke hopes that his app will help physics students better understand the universe, without needing to visit a remote and observatory. Instructions on how to install the app can be found here. [University of Wisconsin-Madison]