The runaway fantasies of mind-uploading enthusiasts are documented in a recent BBC article on the topic, an article that also helps to reveal the logic shortfalls of these fervent apostles of what has been called “the rapture of the nerds.”
We are first introduced to a Russian who says modestly, “Within the next 30 years I am going to make sure that we can all live forever,” and who says that he is “100% confident it will happen.” Is he talking about some immortality potion or pill? No, he is talking about the idea that you will be able to copy the essence of your brain to a computer or robot, and that this will give you immortality.
There are quite a few reasons why such a thing won't happen. First, the brain does not store digital information, so the mind is very likely not something that can be uploaded into a computer. Second, there is not the slightest evidence that the brain uses any type of readable code to store information. DNA uses the genetic code, something we can understand and read. But we have zero knowledge of anything like a brain code that we can use to read information from the brain. Nor can we plausibly imagine how such a code could have originated, as it would have to be something almost infinitely harder to explain than the genetic code (the origin of which is very hard to explain).
Third, you could never capture the exact state of a particular person's brain even if you tried to use microscopic nanobots to do such a thing. There have been some reasonable projections about what nanobots can do. For example, we can imagine nanobots that clear artery blockages that are starting to form. You just inject into the arteries a nanobot that is able to detect such a blockage, and then have the nanobot do something to reduce the blockage, perhaps by just releasing a tiny droplet of some chemical. That wouldn't be too hard for a little nanobot only about the size of a cell. But imagine trying to map a brain with nanobots. Each of the brain-mapping nanobots would have to somehow be aware of its own exact position in the brain, so it can record the exact position of each neuron and brain connection it encounters. So if a nanobot comes to a neuron that is 1.334526 centimeters from the left edge of the skull, and 2.734538 centimeters from the right edge of the skull, and 5.292343 centimeters from the back of the skull, then those exact coordinates must be recorded. But how can a microscopic nanobot do that? You can't supply a microscopic nanobot with a little GPS system allowing it to tell its position. So it would seem that nanobots are completely unsuitable for any such job as mapping the exact physical microscopic structure of an organ with billions of cells packed together in a small space.
Then there's the duplication problem. Imagine if there was a machine that could scan your brain, and then upload your mind to a robot. Even if that process was done perfectly, the robot would not have your mind. It would instead have a copy of your mind. You may realize this just by considering that if this uploading process didn't kill you, and the robot existed at the same time as you, there wouldn't be two you's. There would be one you, and a copy of you living in the robot. If you then died after this upload, it would not at all be true that you had survived death by the fact that this robot existed.
This has been pointed out many times to mind-uploading theorists, and it seems to have gone in one ear and out the other without ever making contact with their brains. For example, the previously quoted Russian makes this statement: "For the next few centuries I envision having multiple bodies, one somewhere in space, another hologram-like, my consciousness just moving from one to another." Apparently he thinks that he will be able to move from one body to another by just making sure that no more than one of his electronic incarnations is active at the same time.
Imagine it: you upload your body to robot X and robot Y. Your body then dies. Can you now “switch your mind from robot X to robot Y” just by turning off robot X and turning on robot Y, or “switch your mind from robot Y to robot X” just by turning off robot Y and turning on robot X? Of course not. In reality, both robot X and robot Y will at best be copies of you. Your life is not extended beyond the death of your body because either robot X exists or robot Y exists. And it certainly won't be a case of you “switching bodies” because one machine is turned off and another is turned on.
The greedy fantasies of the mind uploading theorists are amazing. If you want to hope for a technological extension of your life, why not just hopefully imagine that you will be able to take some kind of youth serum that will extend your life – or that you will be able to have your brain transplanted into a robot body that might last centuries? No, our mind upload theorists must imagine for themselves something even more extravagant – the ability to switch their minds between different bodies. It's kind of like a person who is not satisfied with just believing that he will go to heaven, but also wants to believe that once he gets to heaven he will rule as the king of heaven.
Let me tell a little science fiction story. Once there was a planet on which most of a continent was covered by a densely packed jungle. The trees of this jungle had long thin branches and vines that could connect with many other trees. A particular tree might have branches and vines that stretched out for hundreds of meters, connecting with hundreds of other trees. But there was something very remarkable about this jungle. When most arrangements of these trees and branches and vines existed, the huge jungle was just an ordinary jungle, no more conscious than a stone. But when there got to be a sufficiently great density of these trees and branches and vines, the jungle became a self-conscious mind, and was capable of judgment, analysis, insight, imagination and self-conscious experience.
The story isn't very believable, is it? Why should a jungle become self-conscious merely because there was some particular arrangement of trees and branches and vines? But such a story is just like the story that our neurologists ask us to believe. We are told that we have consciousness merely because of a particular arrangement of densely packed nerve cells and dendrites connecting different cells – an arrangement quite like that of the jungle just described, except that instead of trees it is nerve cells, and instead of branches it is dendrites, and instead of vines it is axons.
Jungle thickets and neural thickets
That is a tale that makes no sense, and the only reason it is accepted is that we don't have some other account of consciousness that does make sense. But one day we will learn of such an account, a completely convincing story of how our consciousness arose. When we finally learn such a story, I suspect it will make perfect sense. At that time I suspect we will look back on our current ideas of the origin of consciousness (and related notions such as uploading human minds into computers) as being laughable fairy tales.