Snakes Lither

The bible says the slither defies comprehension. David hugh, a mechanical engineer at georgia tech made it his mission to decode the slither. When you snake, see snake move on a featureless surface, on a completely flat surface, your heart starts beating faster. How thoy get enough force to move them forward so effortlessly? Was it something in the trigonometry of their muscles? Or how they use their belly scales? Friction, essentially.