あそび (遊び), pronounced “asobi”, means play. It’s an installation by an art student named Yasutoki Kariya which uses computer controlled lightbulbs to recreate Newton’s Cradle, with light visualising the transfer of kinetic energy in the system. And I think it’s absolutely marvellous.

You can read more about asobi on Spoon and Tamago.
With a tip of the lightbulb to Project Argus for reblogging this one!