High Quality Content by WIKIPEDIA articles! The clockwork universe theory compares the motions of everything in the universe to the innards of a mechanical clock. This idealized clock continues ticking along, as would a perfect machine, with its gears governed by the laws of physics, making every single aspect of the device completely predictable. Since Newton unified the description of terrestrial and heavenly motion, scientists originally had good reason to believe that the universe was completely deterministic at least in principle.