I just finished writing a book on memory and dementia, and I have some good news and bad news. The good news is that we can do something about dementia. It's easy, straightforward, and we've only started to get a handle on it in the last ten years. The bad news is that we aren't going to be uploading our brains into computers any time soon. I know, smart guys in the tech world wander around talking about the singularity, the moment when computer brains will surpass human brains. They're wrong. Using existing technology, computers cannot equal a human brain. Not even close. To reach the power of the two pounds of wet, pink sponge in your head, we would need a thousand times the existing world wide web. All of it, in every country in the world, now a thousand times that computing power. Why? It's pretty simple. A computer is based on binary. An on/off switch like a light switch. It's either on or it's off. So a supercomputer is a huge room filled with...