Musings on the Impossible, Part 4

Immortality, But at What Cost?

A vibrant ecosystem is needed to sustain, well, if not immortilaty, then at least extreme longevity

Welcome to the next triplet of essay where I muse on the impossible. Why? Well, isn’t that what truly ambitious science fiction is trying to do? Namely, showing how something that was previously thought impossible (or unachievable) can be achieved^[1], and then (try to) show what happens when it is achieved, for good, bad and anything in between.

It’s also the reason why I read many popular scientific articles on Quanta Magazine^[2], Nautilus^[3], and New Scientist^[4]. That is, to stay abreast of the latest developments and to be inspired. If a particular topic—like consciousness—takes my fancy, I also follow courses (on New Scientist) and buy non-fiction books on the topic (for example, Being You by Anil Seth and, very recently, The World Behind the World by Erik Hoel^[5]), after which I incorporate the gained knowledge^[6] into my writing (in the case of consciousness, that’s the main theme in my novel “The Three Reflectors of Consensual Reality”, which I hope to release in 2025 and serialise on this substack).

Sometimes I look for articles on a specific topic, but more often than not I read any article that sounds interesting, hoping this eventually leads not only to more and better knowledge, but also to lead me into Terra Incognita. Which gets me to immortality.

Immortality has been a desired condition since, at least, the dawn of civilisation^[7]—think the legends of the Fountain of Youth—and is a staple in many science fiction novels and short stories. Before I get into the pros and cons of immortality—and in most cases we actually mean ‘extended longevity’—let’s first go into what may or may not be possible.

First of all, I think that true immortality—that is, literally living forever—is impossible, in the same way that I think about infinity in this Universe: because it does not exist. This Universe—or at least the part of it that we can observe—is not infinitely big. As its observable edge moves away from us^[8], it provides a barrier which we cannot cross, effectively making this Universe not infinite.

Similarly, while we may try to extrapolate extremely far into the future—for example, see Fred Adams and Greg Laughlin’s The Five Ages of the Universe—eventually, after the last black hole evaporates, the Universe^[9] becomes an empty space in which nothing can live. This effectively means that forever is a meaningless concept as fas as ‘living forever’ is concerned.

However, we can try to live longer than we do, on average, today. While it’s called ‘immortality’ in all F&SF writings, I think it’s better to call this longevity, and in some cases extreme longevity. So how can we achieve this? There try are many possibilities, of which I’ll to cover the most common ones:

•     Hibernation;

•     Cryogenics;

•     Life extension medicines and/or treatments;

•     Repair of failing biological [things] through nano- or femto-technology;

•     Uploading life and/or consciousness into a different, more robust substrate;

Hibernation:

Hibernation during the winter months is a common occurrence in several animals like rodents, bats and bears. Since it has a track record with actual living beings, I personally believe a form of human hibernation—especially when considering long interstellar trips—is a better bet than cryogenics. As such, in my ‘Consensual Reality’ trilogy I keep half the crew of an interstellar craft inactive through ‘extreme hibernation’. To be fair, I’m limiting periods of such extreme hibernation to ten years maximum.

This form of longevity is meant to overcome long periods where—supposedly—nothing much happens, such as an interstellar crossing. While this lengthens the total lifetime of a human, it does not lengthen a human’s the active lifetime (unless they’ve received some form of longevity treatment, of which more later).

Cryonics:

Cryogenics

Cryonics could theoretically—if we can get it to work—keep humans conserved for much longer. Nevertheless, personally I think this method has one major problem: evolution has not produced living bodies to survive total freezing. DNA might be recovered, but the individual being, not so much. Yes, certain types of food keep longer if frozen. Living flora and fauna, not so much. I strongly suspect that freezing, then thawing a living being breaks up many of the essential structures in a biological body irreparably. Maybe some future type of nano- or femto-technology might fix this, but I wouldn’t bet my life on it. I’ll be happy to be proven wrong, though.

Again, this type of longevity is also meant to pass a certain period. Apart from interstellar travel there have also ben SF stories where people have themselves be cryonically frozen because they have a disease that’s incurable in the period in which they live, with the hope that a future civilisation will have a cure for that particular disease. Of course, in most of these stories, the protagonist ends up in the aftermath of unintended side effects^[10], such as served indenture to pay for the costs of running the cryonic machine, or ending up in some dystopian/utopian society they either don’t understand and/or hate, and others.

Life extension treatments:

These are already under development by most of the major pharmaceutical companies in the world. Many billions are pumped into researching this, and I think the fact that there is no Universal life extension treatment available—not even for a massive price^[11]—speaks volumes about how complex this is. I suspect—and I don’t mean this in a macabre manner—that it can be linked with cancer research; that is, there are so many different forms of cancer that it’s extremely unlikely that there will be one Universal cure for cancer. Rather, there are—and for the foreseeable future will remain to be—specific treatments for specific types of cancer.

Make no mistake: cancer is a horrible disease and I’ve already lost quite a few good friends to it. But what I’m trying to argue is that a living human body is a highly complex system comprised of many different tissues and symbiotic bacteria (especially in our guts), each delivering both different and multiple functionalities, meaning that things can go wrong in many different places (see cancer and many other diseases). Basically, it’s already a miracle that we live so long.

As such, I suspect that there will not be a single, Universal longevity treatment, but more a series of treatments, medicines and such that each try to keep different parts of the human body going beyond their current expiration dates. Again, future nano- or femto-technologies may be instrumental in this, but then again they will be separate nanomachines targeting separate parts.

What life does is gradually replacing all living matter with fresh material^[12]. This is how it lengthens survivability. That ‘fresh material’ comes from the ecosystem in which we live. So not only for our current survival, but also for longevity or extreme longevity it will be necessary to maintain a healthy ecosystem, as well.

Therefore, many interstellar spaceships in science fiction are small ecosystems in themselves. For the same reason, new planets or moons need to be terraformed^[13]. What an ecosystem does is recycle the waste of some of its inhabitants by turning it into food for some of its other inhabitants, and vice versa (and in reality the relationships are more complex, but this is the general idea). So in order to keep a healthy ecosystem one needs a constant input of energy (in our case this was and is the sun).

Meaning that if we develop functional longevity treatments, we will still need a functional ecosystem to go with it, effectively limiting the longevity of the individuals to the longevity of the system.

The ecosystem angle

TL;DR: IF YOU REALLY WANT TO LIVE EXTREMELY LONG, YOU ALSO MUST BECOME A TREEHUGGER;

Which brings us to the potential problems with maintaining extreme longevity in biological bodies:

•     Needs a constant influx of energy, so will only last as long as this energy is delivered;

•     If the humans do not procreate, then evolution has effectively been halted. However, these ecosystems are a product of evolution, meaning that we don’t know if they can maintain a literal status quo forever;

•     If the humans do procreate, they will need ever larger ecosystems, meaning human civilisation will need to keep expanding to other solar systems. Assuming there are no aliens or other matters preventing us from inhabiting and terraforming other systems, then the longevity will start to end the moment we have fully settled the Milky Way^[14];

•     Thus biological life will slowly die out as the stars run out of fuel^[15];

Uploading life and/or consciousness into a different substrate:

Mind and consciousness uploads are a staple in science fiction, at least from the cyberpunk days. While at this point in time we do not know how consciousness works, how the brain generates it and why it generates subjective experiences^[16], I do think that it is not theoretically impossible to replicate consciousness in a different substrate^[17].

There is one big problem with this: uploading your consciousness may very well mean that you’re putting a duplicate of yourself in a machine environment, meaning that the original remains in your body (excellently explored by Greg Egan in his seminal short story “Learning to Be Me”). This means that the original “you” dies while the duplicated “you” lives on.

The only way around this is finding a way to transfer a human consciousness from the brain into a machine environment. Neuroscientists like [the Italian guy] think that this is impossible because our self is too closely linked to our body (through our nervous system). This might mean that in order to perform a transfer, the complete body must be simulated in the machine environment. It’s possible that this is not possible (meaning there are things in the biological body that machine software cannot duplicate). Something to keep in mind.

Another thing to keep in mind is that this different substrate—just like human bodies—is also prone to entropy, meaning its parts will wear down if not constantly maintained to replaced in a timely manner. In science fiction VNMs—Van Neumann Machines—are often imagined as performing such tasks; that is, machines that can replicate themselves—so there’s always a fresh amount of them available—while also maintaining the machines that run the uploads.

Upload of a human to amachine substrate

Problem is that this is not an ecosystem in itself, meaning such VNMs can only replace themselves and keep the machine substrate on which the uploaded humans run if they have a sufficient supply of raw materials. For that matter, if one is really serious about machine-driven longevity, one would need to design an ecosystem for a machine environment.

In the most extreme case—which is depicted in Charlie Stross’s Accelerando novel—we might transform the whole solar system into a Matrioshka Brain surrounding the sun, making all matter (except the sun) intelligent^[18].

There are several advantages of uploading a human into a machine, because machines can be designed to withstand, or even thrive in the hostile environment of outer space. Still, extreme longevity machine uploads still need some kind of ecosystem which will run out of the available energy runs out.

TL;DR: EXTREME LONGEVITY IS ULTIMATELY LIMITED BY THE AVAILABLE ENERGY MEANING THAT WHEN THE STARS DIE, SO DO OUR EXTREME LONGEVITY SUCCESSORS;

Finally, we have the outliers for immortality^[19] (or some form thereof):

• Stasis fields—most famously implemented by Vernor Vinge in The Peace War and Marooned in Realtime;

  •    Basically a kind of force field that freezes time. To the best of my knowledge, apart from (electro-)magnetic and gravitational fields, there are no other forms of fields. Also, I don’t see how time would be experienced differently inside such a (imaginary) field, unless it moves with a considerable fraction of the speed of light. Therefore, if a starship moves with a considerable fraction of the speed of light, it effectively becomes a fast-forward time machine as time on board moves slower than that of the Universe outside it.

• Time crystals;

  •    Quite possibly, machines (computers) are not the only possible substrate for uploading. If we could upload a human into a so-called time crystal, then that human could theoretically live forever because there would be no entropy within that time crystal. The downside being that one would be completely cut off from the rest of the Universe^[20].

• Other Universes (see below);

• The inside of a black hole (also see below);

Please note that I’m not pretending that this list is complete, as there most probably are things I’m overlooking. Feel free to mention those in the comments.

Concluding: while I think there are possibilities to extend life considerably, I strongly suspect that they will go hand in hand with maintaining a viable ecosystem^[21] (be it a biological, mechanical or previously unimagined alternative). Now suppose we have achieved extreme longevity, what can we do with it? In other words, what are worthy, extreme long-term goals^[22]?

Here are a few I can think of:

•     Explore the scientific method until as much as physically possible is found and/or proven about how this Universe works;

•     Explore the galaxy;

•     If there are aliens: explore alien worlds^[23];

•     Find a way to cross the intergalactic void, then explore other galaxies;

•     Develop a galactic ‘Library of Babel^[24]” that stores all the important information about the galaxy;

•     Find a way to deal with entropy;

•     If the above is impossible, find a way to enter a different Universe, with different physical laws—ones that don’t have entropy as an effect—then find a way to live there (this is basically what the Xeelee did in Stephen Baxter’s Ring^[25]);

•     If the above is possible, make it easier for other star-faring races to get there (I provide a possible way for that in my short story “Machine Intelligences Don’t Care About the Fermi Paradox^[26]” and in my novel “The Transcendence of Consensual Reality^[27]”;

•     Find a way to live inside a black hole—especially a supermassive black hole—as this will exist for an exponential time after the so-called ‘heat death of the Universe (I explore this one in a novella called “The Cryptomancers at the Heart of the Galaxy”, on which I’m working right now);

To wrap this one up, I’ll restate that musing on impossible things not only helps me extend my knowledge and imagination, but also provides material to be used in my science fiction writing. Also, this comes quite naturally to me, as I am an engineer by education and trade, so I always wonder how things work. In the day job these are propulsion systems, in my SF spare time it is almost everything else. Many thanks for reading, and stay tuned for parts 5 and 6, which will be about the speed of light (and if we can break or by-pass it) and entropy (ibid)

Information capture and escape from a black hole. Please note that “Page time” basically means 10 to the power 40 years or ten duodecellion years—a thousand billion billion billion years—in which life might be sustained inside a black hole, far beyond the heat death of the Universe

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Author’s note: I’ve updated the essay by replacing “cryogenic” (the branch of physics dealing with very low temperature ) with “cryonic” (the technique of deep-freezing bodies). Many thanks to Jonathan Reid for pointing out the error.

^[1] even if many SF novels skip this step;

^[2] Supported by the [Name] Foundation, and I couldn’t find a subscription or donation option;

^[3] Of which I’m a supporter;

^[4] Of which I’m a subscriber;

^[5] Insert link to his Substack;

^[6] Again, for good or bad;

^[7] It is, after all, basically the logical end point of survival;

^[8] Does that mean it’s moving faster than the speed of light?

^[9] Until a new scientific breakthrough predicts a different outcome;

^[10] The good old “be careful what you wish for” theme;

^[11] Which would be pocket change for the billionaires of this world;

^[12] On average, every cell in our bodies is replaced with fresh material every X years;

^[13] Or, in case we find alien life, we will have to adapt to them (the aliens);

^[14] At which point we either stop procreating or find a way to cross the intergalactic void, which is truly immense (the Andromeda Galaxy—our nearest neighbour—is 2.5 million light-years away);

^[15] Meaning it must find other means to survive;

^[16] Referred to as the ‘hard problem of consciousness’ by the Australian philosopher David Chalmers;

^[17] QED, of course;

^[18] Robert [Name - link to article] calls this ‘computronium;

^[19] If the above-mentioned alternatives either do not work, or are not sufficient;

^[20] I use this conceit in my short story “The Time Crystal Cave”, which is doing the rounds;

^[21] Which will also keep life more interesting;

^[22] Of course, there are many stating that they don’t want to live forever because they would literally get bored to death. The solution is easy: such people can kill themselves. If there is extreme longevity, at least we have a choice (now everybody dies after a century, or less—with precious few exceptions);

^[23] Preferably in peace and with mutual consent;

^[24] See the story by Jorge Louis Borges;

^[25] Albeit that they weren’t fleeing from entropy, but from the Photino Birds inside the stars;

^[26] Which appearing in the “The Future’s So Bright” anthology;

^[27] Which goes a considerable amount beyond the premise of the before-mentioned short story;