The law that entropy increases—the Second Law of Thermodynamics—holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations—then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation—well, these experimentalists do bungle things sometimes. But if the theory is found to be against the Second Law of Thermodynamics, I can give you no hope: there is nothing for it but to collapse in the deepest humiliation.
“The Last Question,” by Isaac Asimov (podcast)
If you read just one thing on this site, I’d suggest this story.
“Exhalation,” by Ted Chiang (PDF)
An exploration of life and energy gradients