The little shadow that runs through the grass

revelation2220:

Pictured is the Super-Kamiokande, a giant neutrino detector, buried 1000m underground in Japan. Usually filled with 50,000 tonnes of pure water, the observatory detects neutrinos by watching for interactions with the subatomic particles in the water. These interactions are extremely rare, which is why the detector needed to be built to the scale it is.

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