But the broader lesson of the first Industrial Revolution is more like the Indy 500 than John Henry: economic progress comes from constant innovation in which people race with machines. Human and machine collaborate together in a race to produce more, to capture markets, and to beat other teams of humans and machines.

The heart of science is measurement.

Going a little further into the future, we'll start literally connecting to machines. Some of my colleagues at MIT here - some of them are working on a neural mesh that connects directly to your brain, and they've already done it with some disabled people and allowed them to move objects just by thinking.

It's most useful to think about not jobs but tasks. And within any given job, there are lots of different tasks. If you're a radiologist maybe reading the images machines can be able to do that better, maybe making the broader diagnosis and communicating it to the patients.

Computers get better, faster than anything else ever. A child's PlayStation today is more powerful than a military supercomputer from 1996. But our brains are wired for a linear world. As a result, exponential trends take us by surprise. I used to teach my students that there are some things, you know, computers just aren't good at like driving a car through traffic.

Now comes the second machine age. Computers and other digital advances are doing for mental power - the ability to use our brains to understand and shape our environments-what the steam engine and its descendants did for muscle power.

Technology is not destiny. We shape our destiny.