by Annie Churdar in Tech on Friday 5 April 2013

Never replace the batteries on another camping light again. Thanks to GravityLight by Martin Riddiford and Jim Reeves, we can have free, eco friendly light anywhere. Originally designed as an LED light for poor African countries, this invention gives of light made from the slow decent of whatever weight you place in the bag haning from it. Three seconds of movement in exchange for 30 minutes of light as it descends. Brilliant.