 One might with some justice ask: well, so what? Entrenched scientific theories and principles get overthrown all the time. The caloric theory of heat got overthrown by thermodynamics and the theory of molecular kinetics. Classical Newtonian mechanics got overthrown by quantum mechanics. Newtonian gravitational theory got overthrown by general relativity. Now the evidence from cosmology tells us that the Second Law is just one more in a long line of principles that have not passed the test of confrontation with empirical data. That response, however, does not do justice to the profound faith that physicists have in the Second Law. When Einstein was once asked what he thought physics would look like a century from then, he famously said he thought nothing currently believed would still be held as fundamental, except only the Second Law. Everything else—quantum theory, general relativity—could go, but he could not imagine the Second Law being overthrown. Contemporary physicists feel the same  way.[19]  They love the Second Law. There must be, they demand, a way to reconcile the universality of the Second Law with its seeming violation in the way the universe has evolved on cosmological scales. 