Life 3.0: Being Human in the Age of Artificial Intelligence

This chapter is the most widely speculative of all of Life 3.0 and concerns the far distant future of life in the further reaches of the universe. It also relies more heavily on Tegmark’s background in mathematics and physics and is therefore the most technical. Tegmark’s guiding question is: “If our old perceived limits of life can be shattered by technology, what are the ultimate limits? How much of our cosmos can come alive?” (203). Here Tegmark explores the theme of Humanity and the Advancement of Conscious Life.

Through a number of disparate scientific concepts and theoretical constructions, as well as a series of diagrams and illustrations of these concepts, Tegmark explores the question of the ultimate limit. He speculates on the unlikelihood of encountering alien life, but that if we do so, they will likely also be extremely ambitious. In a section on “Making the Most of Your Resources,” Tegmark discusses ultimate technological limits via the construction of Dyson Spheres, an artificial device big enough to surround a local star, the purpose of which is to provide extensive habitable space for life. The most basic technological limit is reliant on baryonic matter, anything constructed from atoms and the constituent parts of those atoms. In other words, the total rearrangement of the particles of the universe is the utter conceptual limit. He also discusses vastly more efficient sources of energy than those currently in use. These include a “spinning black hole engine,” a “Dyson sphere around a quasar” (the central force of a galaxy), and a “Sphalerizer,” which is “an energy generator acting like a diesel engine on steroids” (215).

Tegmark also engages the question of cosmic colonization and how vast quantities of resources can be accumulated through the settlement of the reaches of the cosmos. Here, Tegmark tackles the expansion of space, the problem of special and general relativity, and the existence of dark matter. He explores various possibilities regarding high-speed space travel and the problem of the ultimate limit of light speed. He believes it would be great luck for a cosmic empire if wormholes, which are currently only a theoretical possibility, could be engineered.

Tegmark is not satisfied with simply investigating how much of the cosmos our descendants could settle. He also wants to know how long this civilization could last. He looks to the extremely far future to determine when the last stars will burn out, when all galaxies will be of reach of one another, and even when “all matter forms black holes, which then evaporate” (229). He discusses the “cosmocalypse,” or the ultimate end of the total universe, and a number of different theories by which this universe could cease. Tegmark believes that it will be superintelligent AIs that exist at this point, not humans, and he is curious as to how much these AIs could eventually compute and learn about the laws of nature. He also speculates about the vast numbers of people that could be generated in simulation programs and given meaningful pleasant experiences.

Tegmark believes that at the upper limits of technological progress will become nearly obsolete because in the far future, all matter may be rearranged in whatever form necessary. The only thing worth “shipping” (236) across long distances would be information. He explains why the possibility that civilizations of advanced lifeforms might clash is unlikely: “If the distance between neighboring space-settling civilizations is much larger than dark energy lets them expand, then they’ll never come into contact with each other or even find out about each other’s existence, so they’ll feel as if they’re alone in the cosmos” (240). Tegmark believes, contrary to the views of most, that human beings are currently alone in the cosmos, so that the aforementioned civilizational contact is not only unlikely but impossible. Tegmark references his previous book, Our Mathematical Universe, in which he goes into detail about these views.

Tegmark ends the chapter with a plea for continued technological development. Given his view that there are no alien lifeforms in the universe, the reality of conscious life is dependent on human beings, which gives us an enormous responsibility. At the outset of the chapter, Tegmark writes the following:

To me, the most inspiring scientific discovery ever is that we’ve dramatically underestimated life’s future potential. Our dreams and aspirations need not be limited to century-long life spans marred by disease, poverty, and confusion. Rather, aided by technology, life has the potential to flourish for billions of years, not merely here in our Solar System, but also throughout the cosmos far more grand and inspiring than our ancestors imagined. Not even the sky is the limit. (203)

This is all only possible, according to Tegmark, if we continue on the track of ever-increasing technological expansion and we do so in a safe, smart way. Otherwise, he believes, the end of the human rise is guaranteed: “if we don’t improve our technology, the question isn’t whether humanity will go extinct, but merely how: will an asteroid, a supervolcano, the burning heat of the aging Sun or some other calamity get us first?” (248).