what does it mean to be immortal?

I'm re-reading that old two-part essay on artificial intelligence by Tim at Wait But Why (Part 1, Part 2). One of the big things that Tim suggests superintelligent AI could help with is the attainment of species immortality. This is a collective term meant to describe the idea of a species that never goes extinct, but it leaves open the question of individual immortality. In theory, humanity could already be enjoying species immortality right now: what's currently to stop the species from going on and on and on? Tons of factors, I'm sure you're saying in your head. And whatever factors you're thinking of, ranging from war to famine to disease to the invention of something species-destroying, they must apply to individual humans if they apply to the species as a whole.

JRR Tolkien's elves (or Elves) are considered immortal insofar as they can't die of old age despite their ability to age up to a point. You can bring an elf down (or bring its body down) with a well-placed arrow or axe blow, though, and elves do seem to eat, which implies that they need a food supply. But as long as they encounter no arrows or axe blows, and as long as they have food, elves can, in theory, soldier on forever. (I don't think elves have species immortality, though, because they seem to have died out by our time... unless they interbred with us humans the way Neanderthals are said to have interbred with Homo sapiens.)

So that's one form of immortality: you age up to a certain point, and as long as you can take care of yourself the way regular mortals do, you can last forever.

The villain Michael Meyers from the Halloween franchise offers a different picture of immortality: being unkillable. Stab him with knitting needles, and he comes back. Pitch him off the second floor of your house after filling him with lead, and he comes back. In this type of immortality, you can be damaged, but the damage doesn't stop you or even hinder you. (It's tempting to bring up Marvel hero Wolverine and his healing factor, but as we see in "Logan," Wolverine's own adamantium skeleton ends up chewing away at his life.)

Beings of spirit are often considered immortal, immune to the woes of the flesh, but we should qualify that: if these beings are part of a larger pantheon of creatures or reside within a certain theological framework, they might not be immortal at all: in such a scenario, they're not beginningless, for they've been created, and that same creator can destroy them. These spiritual beings could theoretically be immortal if, after having been created, they're left alone by their creator, but that's an immortality contingent upon deific forbearance. These beings can also, depending on their nature, be killed by other beings like them in some sort of celestial war that takes place outside the awareness of most humans.

In science fiction, certain alien races somehow evolve beyond or otherwise transcend their mortal forms to become beings of light or pure consciousness (like Arthur C. Clarke's monolith-creating entities), making them able to move freely about a galaxy unhindered by any need for a spaceship, food, air, etc. These beings sometimes even escape the confines of our three-dimensional existence, but whether their immortality can last beyond the age of the universe makes for an interesting puzzle. They aren't under the threat of a creator that can destroy them, but the material world itself presents a hard limit they can't necessarily transcend... unless we get into multiverses and the like.

So what could Tim mean when he speaks of species immortality? What type of immortality is he talking about? I suspect he means something close to the elvish version: individuals can die,* and immortality comes with conditions like food supply and the need to live in an irenic environment, but the species as a whole can continue indefinitely with the help of AI. I imagine there being some sort of transhumanist angle in all this: maybe the AI cracks our genetic code, fiddles with our telomeres (end parts of DNA that are markers for, or maybe causes of, aging), and voilà—as long as we have what we need to meet our human needs, we can witness the passage of eons. (There's probably an implication that we'd spend these eons in a healthy and vigorous state because, after all, what would be the point of living millions of years in the decrepit body of a 90-year-old? So again, like the elves, we'd age only up to a certain point, then enjoy a sort of biological stasis.)

There's the associated question of whether immortality is desirable (boredom is possible once knowledge and experience span galaxies), and another question related to our intellectual capacity: a body that lives forever still has a brain that can learn and absorb only so much, so what happens when the mind reaches "full"? Human immortality would have to include the idea of minds that can expand infinitely, just for sanity's sake. That, or we'd have to forget things as a way of taking in new knowledge.

But those are questions for a different blog post. How about you? Do you see species immortality as a desirable goal? Do you welcome the arrival of an artificial superintelligence that will seem godlike next to our puny, limited minds? Is there a chance that we might see the arrival of species immortality within our lifetimes?

__________

*Technically, elves are somewhat docetistic in that they're immortal souls inside mortal bodies. I'm not a Tolkien expert, but I get the impression that elves are fundamentally or essentially spiritual; at the same time, their material bodies can theoretically last forever since elves in their mortal form aren't prey to disease and other natural infirmities.