of the Earth is the first step toward achieving humanity’s interstellar potential, what Max Tegmark, a physicist at MIT, has called our “unlimited cosmic endowment.”5
Colonizing at the Speed of Light
Yet, once it becomes evident just how much is at stake, another point comes into view. It matters greatly, not only that humanity expands, but how quickly. On one self‐consciously conservative estimate, every second that we delay colonization of the Virgo Supercluster is “a loss of potential equal to about 1014 potential human lives.”6 That is one thousand times as many human lives as have existed until now.
The opening of the Ring System is even more important than it might seem. About 130 years prior to the beginning of the series, humanity had barely begun to colonize our solar system. The settlement on Mars was dependent for resources on Earth, a planet that was struggling to provide its own inhabitants with the wherewithal for survival. The invention of the Epstein drive changed this situation radically. By allowing humans to move much more quickly throughout the solar system, the inhabitants of both Earth and Mars could begin to extract and utilize the resources of the asteroid belt and the moons of the giant planets beyond. The Epstein drive’s importance is made clear by the fact that during the first four seasons, the only substantial flashback we see is to Solomon Epstein’s invention of the drive named after him (“Paradigm Shift”). Improvements in the Epstein drive continued for more than a century, and the results rightly impress. As the series begins, the construction of the LDSS Nauvoo, a generation ship with the most sophisticated Epstein drive ever created, the G4000, is close to completion. The G4000 is so powerful that eight of them can accelerate a ship that is 2 kilometers long and half a kilometer wide to over 10 percent of the speed of light. By way of contrast, the tallest building as of this writing, the Burj Khalifa in Dubai, is not even half the size of the Nauvoo. Moreover, the fastest humans have managed to travel in space is 0.0037 percent of the speed of light, just 1/27th of the speed of this generation ship.
Even so, the Nauvoo would have taken about 100 years to reach its goal, the Tau Ceti system, a mere 12 light years away. The journey of the Nauvoo would have exposed its crew to a century’s worth of extrasolar risks, all of which it would have to endure without any possibility of help. Moreover, even if the inhabitants of the Nauvoo were lucky enough to avoid 100 years of extreme danger, Tau Ceti might not have a world habitable by human beings. The journey could easily have been a literal dead end for everyone involved. Now, consider the fact that the Milky Way’s diameter is between 170,000 and 200,000 light years. Hence, relying on Epstein drives to explore and colonize the galaxy would take hundreds of million—if not billions—of years and cost an unimaginable amount of future human lives.
In contrast, the Ring System presents humanity with over 1,300 portals to worlds that they know to be habitable. The system allows journeys that would take unnumbered generations millions or billions of years to be reduced to a matter of months. For example, a mundane research vessel like the Edward Israel traveled from Ceres Station, just beyond Mars, to the planet Ilus in a mere 18 months. Though we are not told how far Ilus is from our solar system, it could easily be tens of thousands of light years. Furthermore, though the Belter settlers on Ilus, such as Felicia, Jakob, and Lucia Mazur, were clearly on the bleeding edge of human expansion, the Ring System allowed them to remain connected with the rest of humanity. They arrived on Ilus with limited supplies, but they planned to extract lithium from the planet so that some of them could return through the ring to our solar system. Unlike the would‐be colonists on the Nauvoo, these settlers didn’t have to do the impossible and plan for every contingency. To be sure, the Belters faced great dangers on Ilus—and not only from Royal Charter Energy’s goons. But colonizing the rest of the Milky Way galaxy via the rings would be many orders of magnitude less risky for individual settlers than doing so while relying on Epstein drives. More importantly, it would also be many orders of magnitude faster.
Unimaginable Opportunities
We can now return to the debate between Gao and Avasarala. Clearly, Gao underestimated the potential benefits of rapid expansion by means of the Ring System. Not only could doing so provide better opportunities for billions of humans today, it could make possible orders of magnitude more human lives in the future.
But the debate is not over. We have only looked at one side of the ledger.
The risks involved with using the Ring System are clear from the Eros Incident. Gao acknowledges this, but she maintains that, given the “unimaginable opportunities” provided by the Ring System, the “real danger of Eros is that we only react to it in fear.” Always ready with the pithy rejoinder, Avasarala retorts that the real danger of the Eros Incident was “that it was about to kill everybody on Earth” (“Oppressor”). She is concerned with the fates of the 40 or so billion human beings alive at the time of The Expanse. In order for her response to Gao to convince us, Avasarala needs to expand her circle of moral concern beyond those alive today to those who will live in the future. Risking the lives of 4 × 1010 humans for the sake of the lives of as many as 1071 humans seems more than reasonable. At that level, the population of the solar system is a rounding error at more than 50 decimal places.
However, this line of thought is flawed. It involves comparing the gains for all humans who will ever live if we successfully colonize the galaxy with the losses for all humans who exist right now if we go extinct as a result of using the Ring System. This calculation ignores all the humans who would have existed if we either did not use the Ring System or were more cautious in its use, as Avasarala suggests. In other words, Avasarala’s response to Gao is most convincing when we think of using the Ring System as what philosophers call an “existential risk.”
Ord defines existential risk as “a risk that threatens the destruction of humanity’s long‐term potential.”7 If use of the Ring System kills the current generation of humans, 40 billion people die. As bad as that is, the result is actually much worse. It also prevents the existence of all future human beings.
Recall Parfit’s point: even if we remain earthbound, we might live here for another billion years during which time about 1016 humans can live sustainably. Yet, our comparison is not the number of humans on Earth, but the number in The Expanse. Humans have already begun interstellar travel and colonizing the galaxy. Even at radically subluminal speeds that will delay colonization of the galaxy by tens or hundreds of millions of years, the potential number of human lives could come within several orders of magnitude of the potential number of humans if we did successfully use the Ring System.
Here, then, is Parfit’s second main insight (promised earlier): the value of preventing human extinction and thereby making the fulfillment of humanity’s long‐term potential more likely is much, much higher than it might seem. Given what is at stake, Avasarala’s response to Gao seems strongest when it is framed in terms of existential risk. As noted, the protomolecule has already come close to driving our species to extinction. More importantly, use of the Ring System is closely related to whatever killed its mysterious creators 2 billion years before the events of the series. Those creators were destroyed despite having advanced their technology to something indistinguishable from magic. It might not be possible to say with any precision just how hazardous use of the Ring System is, and we do not want to minimize the difficulty of making rational choices under conditions of ignorance. Despite the benefits the Ring System might offer, it does not seem like an existential risk worth taking. Our future, flawed as it is, is too good to endanger.
Therefore, Avasarala should have won the debate with Gao, and humanity should say “Thanks but no thanks” to using the Ring System—or at least use the system with far more caution than Gao advocates.
Or so says this philosopher.
Unfortunately, history