How Humanity Could Last Forever

How Humanity Could Last Forever
Illustration: Elena Scotti (Photos: Getty Images, AP, NASA)

Our species will face no shortage of existential risks in the coming decades, whether it be from nuclear war, climate change, a bioengineered pandemic, artificial superintelligence, molecular nanotechnology, or threats we have yet to conceive. Despair, cynicism, and misanthropy will get us nowhere, and we need to start thinking of practical ways to ensure the ongoing survival of our species.

Our universe has been around for almost 14 billion years and will probably continue to exist for many more billion years. Homo sapiens have been around for approximately 300,000 years”not even the blink of an eye, in cosmic terms. We shouldn’t squander our incredible opportunity for a prolonged existence.

Of course, by “we” I’m referring to future offshoots of humans, as our species is likely to change dramatically over the coming eons, should we successfully stave off extinction. Moreover, if we are able to avoid an apocalypse and get our shit together, it’s fair to say that the indefinite prolongation of life is an inalienable good, assuming we enter into a benign mode of existence. We should want to do this, as the alternative”oblivion”isn’t much of a choice. Consequently, it’s something we should be seriously considering.

The first step will be to avert the climate emergency we’re embroiled in. Technological, social, and economic progress will be very difficult if all our energy and resources are used to mitigate the threats posed by a deteriorating environment. We must also find ways to sustain a growing global population, alleviate stresses caused by the uneven distribution of wealth, and live sustainably on a planet with finite resources.

As urgently, we need to confront a grim reality: Our civilisation will soon have to juggle an increasing array of existential and catastrophic risks, in which each added doomsday scenario will boost the odds of our self-destruction by orders of magnitude. That we devise sensible, practical solutions is paramount, if our civilisation”and our species itself”is to last forever.

Distributed Humanity

Creating powerful safeguards, accountable governments and institutions, and effective, enforceable global-scale policies are all important if our civilisation is to survive into the 22nd century and beyond, but there’s a sad fact we have to consider: Our current state of technology is forcing us to keep all our eggs in one basket. Accordingly, we need to become an interplanetary species.

Once we develop the capacity to live off-planet, however, it might be best for us to break off into separate groups and head in different directions”even if it means forever losing contact with each other. It’s an idea I call Distributed Humanity.

Finding ways for us to live away from Earth should be one of our biggest priorities, but our thinking needs to be much grander than that. We also need to develop an interstellar mindset”possibly even an intergalactic mindset”should we want our civilisation to hang in there until the final days of the cosmos.

As it stands, we have yet to develop a viable, self-sustaining biosphere, which, when you think about it, is really discouraging, if not completely alarming. During the 1970s and 1980s, the Soviets experimented with BIOS-3 in Siberia, but the system relied too heavily on resources from the outside to be considered a true biosphere. As for the $US200 ($303) million Biosphere2 project of the 1990s, it simply didn’t work: The dwelling exhibited fluctuating CO2 levels, insufficient amounts of oxygen, acidic water, and even inhabitants who displayed social dysfunction after being cooped up for so long.

These failures mean Earth boasts the only functioning biosphere that we know of. This is troubling news, because we’re going to need artificial biospheres if we’re to live off the planet, whether that’s on the Moon, Mars, or a generation ship heading toward the nearest habitable exoplanet.

We consequently need to reboot our biosphere projects, and not just because they would enable life off the planet; self-sustaining biospheres could eventually become a requirement on Earth, should our environment collapse to shit. Moreover, they could also inform future efforts to geoengineer our planet, and possibly other planets, like Mars.

We should also adopt an interstellar approach to space exploration. We won’t be able to send colonists to another star system for quite some time, but the day is fast approaching when we’ll be able to dispatch probes to explore distant exoplanets.

An idea floated by the late Stephen Hawking and billionaire Yuri Milner calls for the construction of an interstellar starship that could travel upwards of 20 per cent the speed of light.

Incredibly, we could possess the technologies required to do this in just a few years. Such probes would be sent on reconnaissance missions, alerting us to the presence of potentially habitable worlds. From there, we could build and launch spaceships filled with hopeful colonists.

Assuming we’ll find ways to live off the planet, a state of Distributed Humanity would help us to avoid collective mass destruction, whether through natural or self-inflicted causes. Spreading ourselves across the Milky Way would prevent all of us from getting killed in a self-inflicted apocalypse, for example, or prevent the widespread proliferation of existentially dangerous pathogens. Also, if one group were to be destroyed, either by some natural calamity (such as a nearby star going supernova or by its own hands), other groups would live on.

A downside of Distributed Humanity is the potential for convergent risks. Dispersed groups, despite having no contact, could still evolve along parallel lines and potentially stumble upon the same ways to die”while at the same time not being able to alert other groups to looming threats. These convergent risks could involve the creation of a dangerous form of artificial superintelligence, a fatal physics experiment, regressive and irrecoverable modes of existence (like a totalitarian political modality), or something else we have yet to conceive.

Post-Biological Existence

Avoiding extinction is all fine and well, but we also need to become more durable and resilient as individuals. If we’re going to live in space, we’re going to have to biologically re-engineer ourselves. But our chances of long-term survival will be dramatically heightened once we transition from biological to digital modes of existence (though engineered negligible senescence for biological organisms shouldn’t be ruled out as a possibility). Sounds extreme”and it is”but life as either a cybernetic or digital being presents some benefits.

First and foremost, we’d have indefinite lifespans. An uploaded digital being could live in a robust virtual-reality environment hosted inside a supercomputer, the location of which doesn’t really matter (though an argument could be made that it should be placed somewhere cold to maximise computational efficiency). Entire civilisations could live on a single supercomputer, enabling the existence of potentially trillions upon trillions of individuals, each of them a single brain emulation. These supercomputers could in turn be duplicated and sprinkled across the galaxy and beyond, in what could be described as Distributed Posthumanity.

Various futurists have speculated about the powerful supercomputers needed to run these brain emulations and, collectively, posthuman civilisations. The late physicist Robert Bradbury (whom I had the privilege of collaborating with on our 2011 JBIS paper on Dysonian SETI), predicted the existence of what he called Matrioshka Brains. These hypothetical megastructures would draw their power from nearby stars, allowing for tremendous computational potential. A similar idea, called Jupiter Brains, would work on a smaller, planetary scale. Given the finite nature of stars, however, digital civilisations would have to eventually relocate to find alternative energy sources.

Another key benefit of digital existence would be the ability to back ourselves up to the cloud. The death of a brain emulation, say on account of a natural disaster or some unforeseen internal problem, would be tragic, but a reinstated copy or copies of that person could live on.

Digital existence could also allow for disembodied travel through space at the speed of light. Travelling as a decompiled stream of 1s and 0s, an interstellar digital traveller would arrive at a relay station on another planet or some other distant location in space.

This is all highly speculative, of course. We’re not yet entirely sure if the human mind can be translated in the ways described here or if digital life is actually safer or saner than biological existence.

In this posthuman, postbiological digital mode, we could conceivably eke out an existence until the end of the universe. Even then, we might still find ways to persist until the last possible minutes, quite literally.

Cultural Immortality

Failing all of this, we might still find other ways of living forever, though in a more symbolic sense.

Similar to how NASA’s Voyager probes were each equipped with the Golden Record“a 12-inch, gold-plated copper disk encoded with sounds and images from Earth”we could also send a cultural time capsule into the depths of space, but with considerably more detail. The Voyager probes were launched prior to the digital age, and emerging storage technologies will hold a lot more information.

Back in 2016, for example, scientists developed a new storage system that can encode data at the atomic scale. In tests, the device was able to pack 500 terabits onto a single square inch”enough to store every book written by humans onto a drive the size of a postage stamp.

In the future, similar technologies could allow us to pack the entirety of human culture onto a storage medium, load it onto an interstellar probe, and send it into deep space. Should an extraterrestrial civilisation be lucky enough to intercept this probe, they’d have an entire civilisation’s worth of information to parse”assuming we could create a kind of Rosetta Stone to assist with the translation.

Alternatively, we could transmit this data into space via radio waves or laser pulses, but the fidelity of this data would be vastly diminished (sending it out as a repeating digital beacon would help).

In addition to sharing our cultural, scientific, and technological knowledge, we could also impart important historical lessons, wisdom, and advice.

Lastly, we could leave our cultural artefacts right here on Earth, as a kind of monument to ourselves once we’re gone. At the same time, these monuments could serve as a cautionary tale to visiting extraterrestrials”a warning that they shouldn’t repeat the mistakes made by a species left alone to fend for itself in a forgotten corner of the Milky Way.