Around the twenty-first or twenty-second century, a scientific experiment finds that a certain ritual (they were trying to make cold fusion) causes a heat difference to appear in fluids. For instance, the center of a bucket of water may boil, while the outside mists up, or even gets covered in frost.
These scientists slowly conclude that the ritual is indeed doing an energy transfer that actually breaks the second law of thermodynamics, which states that temperatures even out over time, without applying work (like a fridge does).
However, the second law of thermodynamics is a law. It has been observed in the universe at large. In theory, this ritual (just requiring contact between various common molecules such as water and
cheese crystals of quartz). It should have happened loads of times during the formation of the planets, even leading to the formation of various new forms of astronomical objects, like heat sources that aren't stars or gas giants.
The implications are limitless: Europa could easily have a liquid surface, and so on and so forth.
The question is, why didn't this happen? Why is this fictional universe observably similar to the real one? Why do thermodynamics seem to be valid?
Edit: The ritual literally consists of liquid water coming into contact with quartz. This reverses entropy, causing even temperatures to... unbalance. Heat migrates to the center. There is no limit to how much heat can migrate, although the rate of migration is influenced by the size of the crystal and the volume of water. Heat still moves from hot to cold, reaching an equilibrium eventually.
This "ritual" does not require human intervention, or anything similar.