Robots R Us

If we are to re-create the powers of the human brain, we first need to understand how complex it is. There are 100 billion neurons, each with thousands of connections and each connection containing about 1,000 neural pathways. I've estimated the amount of information required to characterize the state of a mature brain at thousands of trillions of bytes: a lot of complexity.

But the design of the brain is a billion times as simple as this. How
do we know? The design of the human brain-and body-is stored in the genome, and the genome doesn't contain that much information. There
are three billion rungs of DNA in the human genome: six billion bits, or 800 million bytes. It is replete with redundancies, however; one lengthy sequence called ALU is repeated 300,000 times. Since we know the genome's structure, we can compress its information to only 30 million to 100 million bytes, which is smaller than the code for Microsoft Word. About half of this contains the design of the human brain.

The brain can be described in just 15 million to 50 million bytes because most of its wiring is random at birth. For example, the trillions of connections in the cerebellum are described by only a handful of genes. This means that most of the cerebellum wiring in the infant brain is chaotic. The system is designed to be self-organizing, though, so as the child learns to walk and talk and catch a fly ball, the cerebellum gets filled with meaningful information.

My point is not that the brain is simple, but that the design is at a level of complexity that we can fathom and manage. And by applying the law of accelerating returns to the problem of analyzing the brain's complexity, we can reasonably forecast that there will be exhaustive models and simulations of all several hundred regions of the human brain within about 20 years.

Once we understand how the mind operates, we will be able to program detailed descriptions of these principles into inexpensive computers, which, by the late 2020s, will be thousands of times as powerful as the human brain-another consequence of the law of accelerating returns. So we will have both the hardware and software to achieve human-level intelligence in a machine by 2029. We will also by then be able to construct fully humanlike androids at exquisite levels of detail and send blood-cell-size robots into our bodies and brains to keep us healthy from inside and to augment our intellect. By the time we succeed in building such machines, we will have become part machine ourselves. We will, in other words, finally transcend what we have so long thought of as the ultimate limitations: our bodies and minds.