Engineers at Deciwatt were asked to build a light for less than $10 to replace the dangerous and polluting kerosene lamps that are widely used in the developing world, especially where there’s no electricity. GravityLight produces 25 minutes of light from just the force exerted by the weight of a bag of stones, sand or water—anything heavy.
The 25 Best Inventions of the Year 2013
The Gravitylight
Full List
Introduction
Wildly Entertaining
Extremely Fun
Compelling
Interesting
Totally Cool
A Major Deal
World-Changing