How Consensus Can Blind Science

The ruins of Mayan civilization impress anyone who visits. For Harvard astronomer Avi Loeb, they spoke to him about the philosophy of science then and now. Recounting his experience for Nature, he describes the questions that came to his mind:

This summer, I visited the Mayan city of Chichn Itz in the Yucatn Peninsula, Mexico. It has an ancient observatory where priest-astronomers made detailed astronomical observations around AD 600-1200. The ruins -- stepped pyramids, temples, columned arc...