Planets that don't currently sport plate tectonics, such as Venus and Mars, are scarcely habitable. Tectonics might be a requirement of any world that aspires to a rich diversity of life.

When it comes to brains, size matters. It's not all that matters, of course. Whales and dolphins have brains that are larger than humans', but few of the flippered and fluked set win tenure at Stanford. Our brains are the largest in proportion to body size, and they're also highly sophisticated.

Despite the impression you may have from watching too much TV, movies are not about reproducing reality. They're about telling stories.

Seth Shostak Quotes