So, where are the robots? We've been told for 40 years already that they're coming soon. Very soon they'll be doing everything for us. They'll be cooking, cleaning, buying things, shopping, building. But they aren't here. Meanwhile, we have illegal immigrants doing all the work, but we don't have any robots.

If you gave kids peas that didn't look like peas and said they were a space shuttle, they're much more apt to eat them because it's now playtime.

The only way to make something cheaply today is to have it mass-produced. For example, you wear the same shoes as everyone else. If you had a fabber, you could custom-make shoes that perfectly fit your feet. Three-dimensional printing will help us move away from the mass consumption that is so deeply ingrained in our culture.

We tend to think of science as finding equations, like E=MC2, that are simple and elegant. But maybe some theories are complicated, and we can only find the simple ones.