From Weight Into Light.

PhysOrg brightens our day with a fun new invention that’s actually rather old-fashioned. It’s a gravity-powered lamp.

The LED lamp, named Gravia, is an acrylic column a little more than 4 feet high. The entire column glows when activated by electricity generated by the slow, silent fall of a mass that spins a rotor.

The light output of 600-800 lumens lasts about four hours.

It sounds something like an hourglass – flip it over, and it runs for a while all on its own.