We went to the moon using just Newton's laws of motion and gravity. Newtonian dynamics we call it. So then we find out, "Well, this works because there's certain regimes we've never tested it in." Had we done so, we would show that it didn't work: For example, at very high speeds, very high gravity, Newton's laws fail. They just fail. You need Einstein's laws of motion and gravity. Those would be his special theory of relativity and general theory of relativity. Now you invoke those and it works.

With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.

Science is not just 'Here are some facts, learn that'. There's a thread through these stories that, if you know how to tell it because you know how they connect, then it's a thread that will land right in your mind, body and soul.

Something bad happened on both Mars with its dried-up watercourses and Venus with its runaway greenhouse effect. Could something bad happen on Earth too? Our species currently turns row upon row of environmental knobs, without much regard to long-term consequences.

Note, however, that you cannot simply add temperatures the way you can add volumes or weights. Two people in bed, each with body temperatures of 98.6 degrees Fahrenheit, do not normally create a 197.2 degree under-the-cover oven.

The people talking on their cell phone and following GPS instructions to where grandma's house is saying I don't need space - excuse me, that's how you know where grandma lives, and when to make the left turn.

During the 1970s and 1980s, the popular television soap opera As The World Turns portrayed sunrise during the opening credits and sunset during the closing credits... The soap-opera sunrise showed the sun moving toward the left as it rose rather than to the right. They obviously had gotten a piece of film showing a sunset and played it in reverse... Had they called their local astrophysicists, any one of us might have recommended that if they needed to save money, they could have shown the sunset in a mirror before they showed it running backward.