Did you notice today’s Google logo? It celebrates the 374th birthday of geologist Nicolas Steno, and illustrates his most famous contributions, the Law of Superposition and the Principle of Original Horizontality. The Law of Superposition states that the oldest rock layers are deposited sequentially, and the Principle of Original Horizontality states that rock layers form horizontally. See the doodle and read more about Nicolas Steno in this Huffington Post article.
