Contrary to the laws of physics that you can't get energy for nothing; scientists from the University of Tokyo have generated energy from information.
Masaki Sano, a physicist at the University of Tokyo, and his colleagues have demonstrated that a bead can be coaxed up a 'spiral staircase' without any energy being directly transferred to the bead to push it upwards.
Instead, it is persuaded along its route by a series of judiciously timed decisions to change the height of the 'steps' around it, based on information about the bead's position. In this sense, "information is being converted to energy", said Sano.
The team's set-up was inspired by a nineteenth-century thought experiment proposed by Scottish physicist James Clerk Maxwell, which suggested that information could be converted into energy.
To create a real-life version of the experiment, Sano and his colleagues placed an elongated nanoscale polystyrene bead, which could rotate either clockwise or anticlockwise, into a bath of buffer solution.
The team applied a varying voltage around the bead, making it progressively harder for the bead to rotate a full 360 degrees in the anticlockwise direction.
This effectively created a "spiral staircase" that was harder to "climb up" in the anticlockwise direction than to "fall down" in the clockwise direction, said Sano.
When left alone, the bead was randomly jostled by the surrounding molecules, sometimes being given enough of a push to turn anticlockwise against the voltage - or jump up the stairs - but more often turning clockwise - or going "downstairs".
They watched the motion of the bead, and when it randomly turned anticlockwise they quickly adjusted the voltage - the equivalent of Maxwell's demon slamming the door shut on a gas molecule - making it tougher for the bead to turn back clockwise. The bead is thus encouraged to keep climbing "upstairs", without any energy being directly imparted to the bead, says Sano.
The experiment does not actually violate the second law of thermodynamics, but it does show that information can be used as a medium to transfer energy, said Sano.