We account for all the matter and energy that we're familiar with, measure up how much gravity it should have, it's one-sixth of the gravity that's actually operating on the universe. We call that dark matter. It really should be called dark gravity. We don't know what that is.

There's a saying in the scientific community, that every great truth goes through three phases. First, people deny it. Second, they say that it conflicts with the Bible. Third, they say that they've known it all along.

Access to science is greater than ever before. There are more vehicles out there that grant the public access to science. Not to mention the Internet.

The most accessible field in science, from the point of view of language, is astrophysics. What do you call spots on the sun? Sunspots. Regions of space you fall into and you don’t come out of? Black holes. Big red stars? Red giants. So I take my fellow scientists to task. He’ll use his word, and if I understand it, I’ll say, “Oh, does that mean da-da-da-de-da?

A common way to compute density is, of course, to take the ratio of an object's mass to its volume. But other types of densities exist, such as the resistance of somebody's brain to the imparting of common sense.

I never got into 'Star Wars.' Maybe because they made no attempt to portray real physics. At all.

I'm an educator, and I'm a scientist, and I speak what is objectively true. And if that offends you, I can try to have a conversation with you to ask why it offends you, and tell you why objective truth should not offend you because that's how the world works.