We should not be ashamed of not having answers to all questions yet... I'm perfectly happy staring somebody in the face saying, 'I don't know yet, and we've got top people working on it.' The moment you feel compelled to provide an answer, then you're doing the same thing that the religious community does: providing answers to every possible question.

It is astonishing to realize that until Galileo performed his experiments on the acceleration of gravity in the early seventeenth century, nobody questioned Aristotle's falling balls. Nobody said, Show Me!

Newton came up with Newton's laws of motion and gravity. They worked. They were working.

They all knew the mothership was coming, they all knew it was a flying saucer, they all knew it came from another planet through the vacuum of space. And so what do they do, to the left of that monument? They set up runway lights. And I'm thinking, if you could travel through the vacuum of space, you don't need runway lights. Runway lights are if you're using air for lift. Aliens would not need air for lift.

As a child, I was aware that, at night, infrared vision would reveal monsters hiding in the bedroom closet only if they were warm-blooded. But everybody knows that your average bedroom monster is reptilian and cold-blooded.

But to measure cause and effect... you must ensure that a simple correlation, however tempting it may be, is not mistaken for a cause. In the 1990s the stork population of Germany increased and the German at-home birth rate rose as well. Shall we credit storks for airlifting the babies?

To assert that the universe has a purpose implies the universe has intent. And intent implies a desired outcome. But who would do the desiring? And what would a desired outcome be? That carbon-based life is inevitable? Or that sentient primates are life's neurological pinnacle? Are answers to these questions even possible without expressing a profound bias of human sentiment? Of course humans were not around to ask these questions for 99.9999% of cosmic history. So if the purpose of the universe was to create humans then the cosmos was embarrassingly inefficient about it.