Neil Tyson talks about UFOs and the argument from ignorance

We need more scientists like Neil deGrasse Tyson. He is not only one of the most prominent astronomers living today, he is also one of the best public communicators on the subject of science.

The argument from ignorance, also known as argumentum ad ignorantiam ("appeal to ignorance" , argument by lack of imagination, or negative evidence, is a logical fallacy in which it is claimed that a premise is true only because it has not been proven false, or is false only because it has not been proven true.