Super-K and other beautiful neutrino detectors...
A team of Japanese scientists have been looking for some of the lightest subatomic particles in the known universe inside what is best described as a giant underground disco ball. These objects of desire, neutrinos, are so small that they pass through solid matter like a comet passing between solar systems. 100 Trillion of them pass through your body just under the speed of light every second before continuing straight through 8,000 miles of planet, rarely nicking so much as another atom. On top of that they have no electric charge thus rendering other subatomic detection devices useless. Recapping: Very small. Very Fast. Very hard to find .
3,300 feet underground in an old zinc mine in Hida, Gifu prefect Japan, the Super-Kamiokande Neutrino and Nucleon Decay Observatory (Super-K for short) has been counting rare clumsy Neutrinos that do bump into things one by one since 1996. The lab has to be underground since unlike neutrinos most subatomic particles cannot pass through the Earth. That's right, the Earth is a coffee filter and this disco ball holds the coffee. Weak coffee - the domed tank holds 50,000 tons of water and only a few spastic neutrinos ever bump into hydrogen atoms in the water molecules thus creating a detectable electron. Those 13,000 silver balls are light sensors that cost over $3000 a pop (and pop they do - over 6500 of them imploded in a freak chain reaction back in 2001).
These sensors are capable of registering the faint blue flash that occurs when a neutrino collides with a hydrogen atom. This flash registers as a streak, like a tiny comet trail. Since neutrinos travel in perfectly straight lines, this tiny streak can be traced out into space infinitely. Several neutrinos were determined to have originated from a supernova in the Large Magellanic Cloud.
Let me tell you, without fail, neutrino trapping devices are always crazy and always beautiful contraptions.
(triggered by and heavily cribbed from this month's Smithsonian Magazine)