Equations of motion modification consistent with conservation of momentum, see variable-mass system. It may be simple to write down the equations of motion in vector form using Newton's laws of motion, but the components may vary in complicated ways with spatial coordinates and time, and solving them is not easy. Often there is an excess of variables to solve for the problem completely, so Newton's laws are not always the most efficient way to determine the motion of a system. In simple cases of rectangular geometry, Newton's laws work fine in Cartesian coordinates, but in other coordinate systems can become dramatically complex. The
Three Laws of Robotics a red indicator light." The red light indicated the wireless uplink to the manufacturer is active, first seen during a software update and later on "Evil" robots taken over by the manufacturer's positronic superbrain. In 2013 Hutan Ashrafian, proposed an additional law that for the first time considered the role of artificial intelligence-on-artificial intelligence or the relationship between robots themselves – the so-called AIonAI law. This sixth law states: In Karl Schroeder's "Lockstep" (2014) a character reflects that robots "probably had multiple layers of programming to keep [them] from harming anybody. Not three laws, but twenty or thirty." In "The