immortality redux

As I make my way further into Part 2 of Tim's Wait But Why essay on AI, I've finally reached the part where he steps back and lets Ray Kurzweil speculate on what artificial superintelligence (ASI) can do for humanity when it comes to immortality. (The following blockquote has been lightly edited.)

The fact is, aging isn’t stuck to time. Time will continue moving, but aging doesn’t have to. If you think about it, it makes sense. All aging is is the physical materials of the body wearing down. A car wears down over time, too—but is its aging inevitable? If you perfectly repaired or replaced a car’s parts whenever one of them began to wear down, the car would run forever. The human body isn’t any different—just far more complex.

Kurzweil talks about intelligent, wifi-connected nanobots in the bloodstream that could perform countless tasks for human health, including routinely repairing or replacing worn-down cells in any part of the body. If perfected, this process (or a far smarter one ASI would come up with) wouldn’t just keep the body healthy, it could reverse aging. The difference between a 60-year-old’s body and a 30-year-old’s body is just a bunch of physical things that could be altered if we had the technology. ASI could build an “age refresher” that a 60-year-old could walk into, and they’d walk out with the body and skin of a 30-year-old. Even the ever-befuddling brain could be refreshed by something as smart as ASI, which would figure out how to do so without affecting the brain’s data (personality, memories, etc.). A 90-year-old suffering from dementia could head into the age refresher and come out sharp as a tack and ready to start a whole new career. This seems absurd—but the body is just a bunch of atoms and ASI would presumably be able to easily manipulate all kinds of atomic structures—so it’s not absurd.

Kurzweil then takes things a huge leap further. He believes that artificial materials will be integrated into the body more and more as time goes on. First, organs could be replaced by super-advanced machine versions that would run forever and never fail. Then he believes we could begin to redesign the body—things like replacing red blood cells with perfected red blood cell nanobots that could power their own movement, eliminating the need for a heart at all. He even gets to the brain and believes we’ll enhance our brain activities to the point where humans will be able to think billions of times faster than they do now and access outside information because the artificial additions to the brain will be able to communicate with all the info in the cloud.

The possibilities for new human experience would be endless. Humans have separated sex from its purpose, allowing people to have sex for fun, not just for reproduction. Kurzweil believes we’ll be able to do the same with food. Nanobots will be in charge of delivering perfect nutrition to the cells of the body, intelligently directing anything unhealthy to pass through the body without affecting anything. An eating condom. Nanotech theorist Robert A. Freitas has already designed blood cell replacements that, if one day implemented in the body, would allow a human to sprint for 15 minutes without taking a breath—so you can only imagine what ASI could do for our physical capabilities. Virtual reality would take on a new meaning—nanobots in the body could suppress the inputs coming from our senses and replace them with new signals that would put us entirely in a new environment, one that we’d see, hear, feel, and smell.

Eventually, Kurzweil believes humans will reach a point when they're entirely artificial; a time when we’ll look at biological material and think how unbelievably primitive it was that humans were ever made of that; a time when we’ll read about early stages of human history, when microbes or accidents or diseases or wear and tear could just kill humans against their own will; a time the AI Revolution could bring to an end with the merging of humans and AI. This is how Kurzweil believes humans will ultimately conquer our biology and become indestructible and eternal—this is his vision for the other side of the balance beam. And he’s convinced we’re gonna get there. Soon.

You will not be surprised to learn that Kurzweil’s ideas have attracted significant criticism.

Forget, for a moment, your own criticisms of this über-optimistic vision of the future that are right now thronging in your head. I have criticisms, too. Note instead that the above description of immortality helpfully answers some of the questions I posed in my previous post. This version of immortality isn't about shedding the human form and becoming abstract, invisible, angelic beings—we'll remain corporeal, even human-shaped, but we'll be increasingly artificial in a radicalized version of Battlestar Galactica's Cylonization of human life. And we'll live for indefinite periods of time... as long as we have access to our rejuvenation facilities. So it's still a little bit like Tolkien's elves, then: like the elves, these Kurzweilian future-humans will take in food and be impervious to disease; they will still theoretically be able to reproduce although I have no idea what DNA might even mean if we're all housed in tough, heartless, artificial bodies filled with self-propelled blood cells. Like the elves, we'll probably still be killable by conventional means unless our toughening includes some sort of structural enhancement that looks sleek but allows us to survive sledgehammer blows, flamethrowers, and maybe even nuclear explosions. Note that this is an immortality that is contingent on the beneficent actions of the ASI: without those rejuvenation facilities, we die. I'm not sure how appealing such a dependent form of immortality would be.

And that may be a problem with ASI in general. If you saw "Captain Marvel," then you know the movie gives us a tantalizing glimpse of the Kree homeworld, which is run by a seemingly benevolent, godlike AI. In my review of the movie, I mentioned wanting to explore that world a bit more; just how dependent are the Kree on their Supreme Intelligence? I suspect that ASI for us humans would amount to the same thing: we might end up enhanced in ways that we can't even imagine right now, but the cost would be utter dependency on the superintelligence. If we're that dependent, are we really enhanced?

As for my criticisms of the above immortality scenario:

1. A car wears down over time, too—but is its aging inevitable? If you perfectly repaired or replaced a car’s parts whenever one of them began to wear down, the car would run forever.

I'm not a mechanic, but even I know that this is not how car repairs work. I've heard warnings from scrupulous mechanics about how a new part in an older car can sometimes lead to performance issues. When the parts of an engine, for example, all age together, there's a sense in which those parts are in sync with each other. A new, shinier, tighter part will have a different "hum" to it, and while it may integrate with the rest of the car over time, it may not. Imagine installing a new, young heart in a body with aging blood vessels. Hemorrhages and aneurysms, anyone? And if you start replacing more and more body parts thinking that that will keep your car from aging (in a "Ship of Theseus" kind of way), you might be in for a rude awakening as multiple parts wear down at different rates, and the whole thing eventually leads to a cascade failure. Immortality can't simply be a matter of putting out fires here and there in an eternal game of existential Whack-a-Mole.

2. intelligent, wifi-connected nanobots in the bloodstream

Sorry, but this only makes me think of hacking. I don't want my blood to be hackable, whether by other humans or by a mercurial AI. You might respond that ASI could create unhackable blood... but that probably means "unhackable by humans." What about the ASI itself if it decides you're not doing what it thinks you should be doing?

3. ASI could build an “age refresher” that a 60-year-old could walk into, and they’d walk out with the body and skin of a 30-year-old.

Larry Niven wrote a short story (found in his collection Neutron Star) about a guy who, thanks to his ship's onboard "AutoDoc," was able to live for thousands of years. But with the accumulation of all that time and experience, he still fell into certain entrenched habits that ended up dooming him. Rejuvenation did nothing to erase the myelinated pathways that corresponded to certain routine mental and physical habits.

4. Humans have separated sex from its purpose, allowing people to have sex for fun, not just for reproduction. Kurzweil believes we’ll be able to do the same with food. Nanobots will be in charge of delivering perfect nutrition to the cells of the body, intelligently directing anything unhealthy to pass through the body without affecting anything.

This might actually be kind of cool. It could lead to all sorts of risky culinary adventurism, especially as people got bored and began to experiment with the funkier aspects of cuisine. But to what extent would we be protected from the effects of the food we ingest? Would we no longer be able to feel the full volcanic force of a ghost pepper? No longer know what it's like to shit fire after engaging in a spicy-noodle challenge?

5. Virtual reality would take on a new meaning—nanobots in the body could suppress the inputs coming from our senses and replace them with new signals that would put us entirely in a new environment, one that we’d see, hear, feel, and smell.

And if that were ever to glitch, it'd be like having a bad trip, I guess: you could end up forever trapped in a delusion and not know it. The whole nanobots-in-my-body thing is too freaky for my taste, especially if there's a chance these bots might accidentally misbehave in some way.

6. Eventually, Kurzweil believes humans will reach a point when they're entirely artificial; a time when we’ll look at biological material and think how unbelievably primitive it was that humans were ever made of that...

Multiple sci-fi scenarios come to mind other than the aforementioned Cylonization. The end of Spielberg's 2001 "A.I.," for example, features a race of futuristic robots that represent the only "life" left on Earth—although it's not obvious how human they are despite being vaguely humanoid in appearance. The robots learned how to manipulate aspects of space-time to be able to conjure up David's human "mother" for a day (I shudder to think what happened at the end of that 24-hour period). "Star Trek: The Motion Picture" hinted that the film's antagonist, V'ger, had been enhanced when the probe reached a civilization of "living machines" (which some Trekkies now hypothesize might have been a Borg world even though the Borg are cybernetic organisms, not sentient machines). 

Kurzweil's vision is literally a dehumanized one, but I can see how his vision is a result of his functionalist point of view: functionalism is the idea that, as long as you've got analog parts that function the same way as the original, then effectively, they're just like the original. Example: a human brain composed entirely of artificial neurons will effectively behave just like an organic brain so long as the artificial brain's parts all interconnect in the exact same way. So for Kurzweil, if we were to swap out our current mortal, fallible, frangible parts for studier ones that could last thousands of years while allowing us to look as we do now, then functionally, we'd still be just as human as before, only enhanced.

7. the balance beam

This last isn't so much a criticism as an explanation for the person who hasn't read Tim's article. Tim uses the image of a balance beam to note that most species on Earth that have walked the evolutionary balance beam have pitched off one side of the beam and into extinction. But what if a species were to pitch off the beam on the other side into immortality? It's an open question, Tim says, as to which way humanity will fall. We could destroy ourselves, leading to our extinction; we could invent a superintelligent AI that destroys us. Or more positively, we could invent this Kurzweilian AI that will allow us to become enhanced and immortal.

Tim's long essay is good fodder for thought. Having been written in 2015, it feels, at some points, almost prophetic. The arrival of ChatGPT seems to fit one of the predictive timelines that Tim mentions, so who knows? We really could be maybe a decade away from human-level artificial intelligence. I admit I'm one of the skeptics on that point because I think some of the problems facing AI development may be insurmountable, but I'm not a robotics engineer, cyberneticist, or any other kind of expert when it comes to future stuff. So from my point of view, all I can say is, We'll see.