Autonomous glider uses ocean’s heat to propel itself, no power required

Scientists from the Webb Research Corporation and Wood’s Hole Oceanographic Institute (WHOi) have been testing a glider that uses no power to propel itself through the ocean.

Instead, the yellow, torpedo-shaped machine has been swimming around since December 2007 by taking advantage of the temperature differences between the warmer surface waters and colder deep waters.

Wax-filled tubes in the glider expand when its in warmer water, changing its buoyancy and causing it to sink. When it reaches a colder temperature the wax contracts and the craft floats back up. This up-and-down motion, combined with the glider’s wings, allows it to move forward through water without any power.

Unfortunately, using any sensors on board the glider requires batteries to power them. However, the scientists believe that the craft can still run on its own for up to six months at a time. So far, they say that the glider has covered thousands of kilometers during their tests.