Beyond: Our Future in Space

by Chris Impey

  Figure 57. A Dyson sphere is the theoretical concept of an energy collection system that can harvest all the radiation from a star. Nikolai Kardashev imagined a scale of increasing energy usage as a civilization matured—from using the energy falling on a planet (I) to using the energy of a star (II), a galaxy (III), and the universe (IV). A Dyson sphere is the technology of a Type II civilization while we are currently less than a Type I civilization.

  The existence of Dyson spheres allows for passive SETI, where no intention to communicate is needed. The premise is that any highly advanced civilization will leave a much larger footprint than we will. Type II or later civilizations may employ technologies that we’re tinkering with or can barely imagine. They might orchestrate stellar cataclysms or use propulsion by antimatter. They might manipulate space-time to create wormholes or baby universes, and communicate via gravity waves. We can look for artifacts as well as messages. Extrapolation is addictive, so some scientists have proposed adding the category of a Type IV civilization that controls space-time well enough to affect the entire universe.

  Why stop at one universe?

  Modern cosmology involves the idea of quantum genesis—tracing back the cosmic expansion projects to an origin in a singularity where the space that now contains 100 billion galaxies was smaller than an atom. The inflationary scenario is an adjustment of the standard big bang to include an extremely early phase of exponential expansion. The idea was developed to explain why the universe now is very smooth and geometrically flat. Inflation has tentative support from the nature of small temperature variations in the cosmic background radiation. If inflation is correct, the universe began as a quantum fluctuation. The precursor state would have been an ensemble of quantum fluctuations, perhaps infinite in number, each with randomly different initial physical conditions. Some of them inflated into large space-times like our own. Others were stillborn. This process can be timeless and eternal (Figure 58). The laws of nature in these parallel universes would differ from the laws with which we’re familiar.11 This, in a nutshell, is the multiverse.

  Figure 58. In chaotic inflation, the precursor state was an endless series of space-time quantum fluctuations. Some of these fluctuations might inflate into macroscopic universes, while others would not. This is the multiverse concept.

  The multiverse is connected to another issue that has been perplexing physicists for several decades: fine-tuning.12 Albert Einstein fervently believed that the laws of physics, when they were fully understood, would be inevitable, elegant, and self-contained. This quality, called naturalness, has been a touchstone in theories of nature ever since. But nature isn’t cooperating. The “standard model of particle physics” precisely explains the interactions of fundamental particles, but the model is governed by more than two dozen parameters, so it’s not elegant or simple and the parameters don’t emerge naturally from an underlying theory. Some quantities—like the mass of the Higgs particle and the value of the dark energy that controls cosmic acceleration—are much lower than physicists expected. They’re dismayed that laws of nature seem to be an arbitrary and messy outcome of random fluctuations in the fabric of space-time.13

  A controversial argument deriving from fine-tuning is the fact that the forces of nature and the attributes of the universe appear to take values required for carbon-based life to exist. If the electromagnetic force was stronger or weaker, stable atoms could not form. If the strong nuclear force was stronger or weaker, carbon couldn’t be created in stars. If the gravitational constant was stronger, stars would be very short-lived; if it was weaker, stars wouldn’t shine or make the heavy elements. The universe also has very low entropy or disorder, which may be responsible for time’s forward sense or “arrow.” In addition, the cosmic values of dark matter and dark energy neither prohibit structures from forming nor cause a collapse too soon for life to be able to form. The point is that while the universe would be physically sensible if any of these quantities took different values, it wouldn’t be a universe with life containing life as we know it.

  It’s unremarkable that the properties of the universe are compatible with our existence. But controversy arises when this anthropic line of reasoning is strengthened to say that the universe must have those particular properties that allow life to develop at some point.

  Inflation and (as yet unproven) string theory could provide a physical basis for a vast ensemble of parallel universes with randomly different properties. Our universe is “special” only in the sense that it contains biology.

  Debate rages over whether the multiverse concept is real science or solipsism. Meanwhile, Alan Guth, the MIT physicist who developed inflation theory in the 1980s, suggests it might provide yet another explanation for the absence of aliens. Assuming plausible probabilities for the multiverse ensemble, young universes vastly outnumber the old ones.14 Averaged over all universes, universes with civilizations will almost always have just one, the first to develop: us.

  Singularity and Simulation

  The conjecture that civilizations more advanced than ours will use an ever-increasing amount of energy is very retro, very twentieth century. In fact, the rate of growth of world energy consumption peaked at 5 percent per year in the 1970s, and it has fallen to less than 3 percent per year now. World energy appetites are likely to rise at even lower rates in the future as fossil fuels become depleted, population growth slows, and the cost of energy drives industry to greater efficiency. We may never reach the usage of a Type I civilization, let alone the energy-guzzling heights of the Type II and Type III civilizations.

  Rather than become grandiose and bloated, an advanced civilization might slim down. Earth’s population and resource use may stabilize within a few decades. But two exponential trends will likely continue unabated: shrinking physical devices through nanotechnology and growing computational power and information storage. Let’s look at each of these in turn.

  Physicist John Barrow has created an alternative to the Kardashev scale for classifying civilizations based on their ability to manipulate matter. The scale progresses from manipulating human-scale objects to manipulating molecules to make new materials, then to manipulating atoms and creating new artificial life forms. The third level is almost within our grasp. Beyond that is the ability to manipulate elementary particles and make entirely novel forms of matter, culminating in the manipulation of the basic structure of space-time. The self-replicating von Neumann space probes that we encountered earlier are incredibly cumbersome when compared with what could be done with self-replicating nanomachines.15

  The frontier of controlling matter at the level of fundamental particles has been explored by artificial intelligence (AI) researcher Hugo de Garis. He writes: “The hyperintelligences that are billions of years older than we are in our universe have probably ‘downgraded’ themselves to achieve hugely greater performance levels. Whole civilizations may be living inside volumes the size of nucleons or smaller.” Alien artifacts may be built into the architecture of matter, leading to a new paradigm for SETI: “Once one starts ‘seeing’ intelligence in elementary particles, it changes the way one looks at them, and the way one interprets the laws of nature, and the interpretation of quantum mechanics, etc. It’s a real paradigm shift away from looking for non-human intelligence in outer space, to looking for it in inner space.”16

  Next we turn to the progress in computation. Exponential gains in processing power lead to the idea of the technological singularity. This is the time, projected to be in the middle of the twenty-first century, when civilization and human nature itself are fundamentally transformed. One variant of the singularity is when artificial intelligence surpasses human intelligence. Software-based synthetic minds begin to program themselves and a runaway reaction of self-improvement occurs. This event was foreshadowed by John von Neumann and Alan Turing in the 1950s. Turing wrote that “. . . at some stage therefore we should have to expect the machines to take control . . . ,” and von Neumann described “. . . an e
ver-accelerating progress and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue.”17

  A dystopian version of this event permeates the popular culture, from science fiction novels to movies such as Blade Runner and The Terminator. Doctor Frankenstein is destroyed by the powerful monster he creates—it’s a venerable morality tale. The possibility that advanced civilizations might be aggressive is the reason Stephen Hawking argues that we shouldn’t try to communicate or reveal our presence. The most chilling example of this scenario is seen in Fred Saberhagen’s Berserker series of novels, where self-replicating doomsday machines are out there watching, ready to destroy life on a planet just as it begins to acquire advanced technology.

  Another variant of the singularity takes current efforts to fight disease and projects them into radical life extension, where technology helps us overcome all our mental and physical limitations. Ray Kurzweil has been the most eloquent proponent of this future. He’s a founder of the Singularity University, where the tech world’s movers and shakers pay tens of thousands of dollars for short courses on the cutting edge in AI and nanotechnology. Critics have mocked the idea of the singularity as the “rapture of the nerds,” and they’ve noted that only the wealthy will benefit from radical-life-extension technology.

  The goal of researchers like Kurzweil is simple: immortality. He thinks that medical nanotechnology will conquer disease, aging, and death. To become postbiological, we’ll need the means to reverse engineer the brain of any human and reproduce it in silicon. The term for this is mind uploading.

  Hans Moravec first outlined the simulation argument in the late 1990s. He projected advances in computation to superhuman capabilities in a few decades. With the premise that the wet electrochemical network of the brain, including consciousness, can be replicated computationally, we’re within striking distance of a computation that’s equivalent to the history of all the thoughts every human has ever had. If one computer can simulate the thoughts of a person, a suitably powerful computer could simulate the entirety of human consciousness. And if we can do that, it would be trivial for any more advanced civilization. Following Nick Bostrom, let’s call this capability “technological maturity.” It’s a modern version of the concept in philosophy known as “the brain in a vat” (Figure 59). This scenario is familiar from movies of The Matrix franchise, where humans are all simulated by a superior civilization, but there are hints of that fact and some learn how to control the simulation. The movies are provocative but somewhat illogical: A simulation that sophisticated would not have “glitches” that revealed to the simulated entities that they were in a simulation.

  Figure 59. There is a long philosophical tradition involving the thesis that reality is an illusion. A modern version of this idea posits that humans are all simulated entities of an advanced alien civilization.

  Philosopher Nick Bostrom has explored the consequences of replicating human consciousness in a computer. He’s formalized the scenario into a simulation hypothesis. Based on formal logic, you must accept one or more of the following propositions: (1) Humans will go extinct or self-destruct before we become technologically mature and able to carry out such simulations. (2) No other civilization that can create such simulations does so. (3) We live in a simulation.18

  Most people react with shock and revulsion to this prospect. After all, we each carry with us our own crisp sense of identity and reality. But the argument deserves to be taken seriously. We might hope to reject the first proposition, since it implies a gloomy outcome for humanity—there’s no reason to believe we’d be luckier than any other civilization in achieving maturity. The second proposition seems unlikely, since it would require a commonality of purpose among disparate civilizations. If any civilizations are creating these simulations, it’s so easy to create a vast number of simulated entities like us that they would outnumber flesh-and-blood creatures. The principle of mediocrity says we’re more likely to be simulated than real. Bostrom admits it’s difficult to assign probabilities to the correctness of the three propositions, but he argues that there’s no reason to assign low probability to the third.

  Philosophers have even written papers about how you should live if you think you are in a simulation. The simulation designers wouldn’t give you a hint of your predicament unless they wanted to, but they might mix sentient with nonsentient creations, leaving you to figure out who the zombies are. If we live in a simulation, then space travel isn’t as adventurous as we imagine; it’s like playing a video game within a video game. And there’s no reason to believe the simulators are not themselves simulated, leading to infinite regression—a problem philosophers and logicians still haven’t figured out.

  If these bizarre ideas have any validity at all, what do they say about our urge for exploration and for leaving the Earth? If reality is a chimera and we are simulated, then space travel is part of the simulation. It’s no more difficult or meaningful than riding a bicycle. Even if we reject this possibility, we can still admit that advanced civilizations may use their powers to create fantastical computations or simulated entities. They could have rich inner lives. They could be purely contemplative. But they’d be entirely bounded by their own capabilities. It would be a hermetic, self-defined existence.

  Like all sentient beings, we have a choice. We can turn inward or turn outward. So far, humans have chosen to explore and to venture into the unknown. It’s not the easy choice and sometimes it carries great risk. But it’s a bracing way to live our finite lives.

  Imagination and Exploration

  We stand at the edge of a vast cosmic shore. We’ve dipped our toes in the water and found it bracing but inviting. Time to jump in.

  Imagination is one of a human being’s most singular gifts, and we’ve used it to create fully realized worlds in art, music, fiction, and poetry. Science is not just a dry collection of facts and theory—it’s driven by imagination. When Newton imagined a cannon on top of a high mountain firing a projectile that would fall at just the same rate that the Earth curved below it, he was imagining space travel more than two centuries before we would develop the technology to leave the Earth’s gravity. Science fiction writers and space artists have long dreamed of other worlds, and the exoplanets being discovered in droves are exotic enough to measure up to their visions.

  Let’s not forget how we got to this point. Animals roam, they seek food, and they expand their range. But only humans have the urge to explore for its own sake. We left Africa and by 10,000 years ago we had forged better lives for ourselves by taming plants and animals and settling into fixed communities. But the curiosity remained. So we harnessed the wind to sail the oceans. Then we loosened the bonds of gravity by using chemical fuels to fly in planes and soar in rockets. The challenges of space exploration have already led us to develop better engines, faster computers, and smarter materials. In the future, space exploration will drive us to develop efficient fuels, miniaturized control systems, and sophisticated medical diagnostics.

  Space travel is urgent and it is real. We have the technology and the means to live and work in space, gain a permanent toehold off-Earth, and explore the Solar System and beyond. No laws of physics stand in our way. If we commit to space travel, it will force us to cooperate as a species, since some of the problems are too hard for any one country to solve. The effort can ennoble us.

  Space travel, however, will never be our top priority. There are poor people to feed, diseases to cure, wars to resolve, and a bruised planet to heal. Yet venturing beyond the Earth challenges our ingenuity in ways that can benefit everyday life. Learning about other worlds informs us how to be better caretakers of this one. These activities can let us be more than a footnote in the history of the Milky Way. Exploration is built into our DNA; we should not resist. Everyone deserves the chance at least once in their lives to be liberated from the heft of the body’s gr
istle and to view the jewels of the cosmos set against the black velvet of night.

  Notes

  1: Dreaming of Beyond

  1. The Genographic Project, sponsored by the National Geographic Society, has used DNA from nearly a million people to map out human migration. See https://genographic.nationalgeographic.com/about/.

  2. Darwin speculated about a tree of life and a last common ancestor based on morphological similarities between species. The size and shape of an organism can be misleading, however, and bacteria are all the same shape, so modern phylogeny uses measures of overlap in the base pair sequences of DNA or RNA. It’s hard to reconstruct linear time using genetic distance, and gene transfer and convergent evolution can cause confusion. When there are many species being compared, more than one tree may fit the data.

  3. “Resolving the Paradox of Sex and Recombination” by S. P. Otto and T. Lenormand 2002. Nature Reviews Genetics, vol. 78, pp. 737–56.

  4. The Geno 2.0 testing kit costs $200 online. After someone sends in a cheek swab, individual results are returned showing the broad pattern of ancestry and degree of genetic overlap with different native populations. The research results are in “The Genographic Project Public Participation Mitochondrial DNA Database” by D. M. Behar et al. 2007. PLoS Genetics, vol. 3, no. 6, p. e104.