This $5 Lamp Is Powered By Gravity (And Just Destroyed Its Funding Target On Indiegogo)

A lamp for $5 that does not require any electrical power source? It may sound like an impossible dream, but two designers in London have built functioning prototypes of GravityLight, a cheap way for people in developing countries t0 light homes, recharge batteries, or power a radio. And they just exceeded their Indiegogo fundraising goal by more than 500 percent with 21 days left in their campaign, so they’ll have the resources to mass-produce the light for less than $5 a unit.

Martin Riddiford and Jim Reeves have spent four years developing GravityLight, which uses the Earth’s gravity to generate enough power to light an LED bulb for half an hour — no electrical grid, batteries, or any external generator required. Using the GravityLight simply requires removing the small white lamp from its bag, hanging it up, filling the bag with about 20 pounds of dirt or rocks, and attaching the bag to bottom of the device. Gravity powers a generator, light fills your room, and every 30 minutes, you hoist the bag back up...