In mathematics, the exponential integral Ei is a special function on the complex plane.

The order of magnitude of a number is, intuitively speaking, the number of powers of 10 contained in the number.

This is at an early stage, but you can show with the exponential growth of the amount of information about the brain and the exponential improvement in the resolution of brain scanning, we will succeed in reverse engineering the human brain by the 2020s.

Two numbers of the same order of magnitude have roughly the same scale the larger value is less than ten times the smaller value.

The amount of genetic data basically this shows that smooth exponential growth doubled every year, enabling the genome project to be completed.

I was a little nervous because maybe the data wouldn't be right, but I've done this now for 30 years, and it has stayed on this exponential progression.

There will come a time, of course, when the exponential growth of discovery and knowledge, which actually began in the 1600s, has to peak and level off, but that's not going to matter to you.