Researchers from Georgia Tech claim they’ve built a robot that can move in curved space without Newton’s third law
By Adam Smith
Scientists have built a robot that defies the standard laws of physics and could eventually help humans travel around black holes.
When humans, animals, and machines move through the world they must push against something – be that the ground, air, or water. This is Newton’s third law: every action has an equal and opposite reaction.
The law applies to flat, three-dimensional space that humans move through, but in curved space forces can differ – and objects can move without frictional or gravitational impact.
As such, researchers from the Georgia Institute of Technology claim they have built a robot that can move in curved space without pushing against anything.
“We let our shape-changing object move on the simplest curved space, a sphere, to systematically study the motion in curved space,” said Zeb Rocklin, assistant professor in the School of Physics at Georgia Tech.
“We learned that the predicted effect, which was so counter-intuitive it was dismissed by some physicists, indeed occurred: as the robot changed its shape, it inched forward around the sphere in a way that could not be attributed to environmental interactions.”
The experiment was done by placing a ‘swimmer’ on a sphere with actuated motors on a freely rotating boom arm. They then connected this system to a rotating shaft so that the motors always move on a sphere, with the shaft itself supported by air bearings and bushings to minimize friction. The alignment of the shaft was also adjusted with the Earth’s gravity to minimize any residual force.
Although the robots’ movements were small – and do not look impressive on the video – the smallest change could have vital repercussions in the same way that a slight frequency shift induced by gravity became crucial to allow GPS systems.
The researchers believe that the principles of how a space’s curvature can be harnessed could eventually allow vehicles to navigate the highly curved space around a black hole.
“This research also relates to the ‘Impossible Engine’ study,” said Mr Rocklin, referring to the notion of an engine that can generate thrust without fuel.
“Its creator claimed that it could move forward without any propellant. That engine was indeed impossible, but because spacetime is very slightly curved, a device could actually move forward without any external forces or emitting a propellant – a novel discovery.”
Nasa has been working on such an engine, called an EmDrive, since 2015, but has not produced any beneficial results yet.