The oncoming trouble I speak of is climate change. It's going to affect all of you in the same way the Second World War consumed people of my parent's generation.

There are two ways to be rich: to have more or need less. It's estimated that we squander about 30 percent of our energy leaving the lights on, the refrigerator door open, and so on. Then there is the enormous amount of food that we expend huge amounts of energy to raise and then throw away.

When we see the shadow on our images, are we seeing the time 11 minutes ago on Mars? Or are we seeing the time on Mars as observed from Earth now? It's like time travel problems in science fiction. When is now; when was then?

If you look back on all the teachers that you liked, I am sure you will find they were very entertaining.

Speaking of human computers, there is a guy named Art Benjamin, he's a human calculator. He says it's a skill he learned as a kid. Now he's a math professor at Harvey Mudd. He can find the square root of a six digit number in a few seconds. Practice.

When we sit down to draw or paint the sun's rays, we generally use yellow because in the morning and the evening with the blue light scattered away so strongly you're left with a little bit of red and it comes out yellowish.

If you want grown-ups to recycle, just tell their kids the importance of recycling, and they'll be all over it.