As I surveyed them from this point, all the other heavenly bodies appeared to be glorious and wonderful,—now the stars were such as we have never seen from this earth; and such was the magnitude of them all as we have never dreamed; and the least of them all was that planet, which farthest from the heavenly sphere was shining with borrowed light. But the spheres of the stars easily surpassed the earth in magnitude—already the earth itself appeared to me so small, that it grieved me to think of our empire, with which we cover but a point, as it were, of its surface.

And as I gazed upon this more intently, “Come!” said Africanus, “how long will your mind be chained to the earth? Do you see into what regions you have come?”

—Marcus Tullius Cicero, The Dream of Scipio, 51 BCE

What kind of future can we create?

Homo sapiens began its existence 200,000 years ago as a handful of tribes living in the Kenyan Rift Valley. There, in our natural habitat, we remained for the following 150,000 years, under conditions of near-complete technological stagnation. But then, for some reason, 50,000 years ago, some of our ancestors ventured forth, to take on the more challenging environments of Ice Age Europe and Asia, diversifying and inventing new ways of doing things as they went, to ultimately settle the entire Earth. The trek out of Africa was humanity's key step in setting itself on the path toward achieving the mature Type I status that the human race now approaches.

The challenge today is to move on to Type II. Indeed, the establishment of a true spacefaring civilization represents a change in human status fully as profound—both as formidable and as pregnant with promise—as humanity's move from the rift valley to its current global society.

Space today seems as inhospitable and as worthless a domain as the wintry wastes of the north would have appeared to a denizen of East Africa fifty thousand years ago. Yet, like the north, it is the frontier arena whose possibilities and challenges will allow and drive human society to make its next great positive transformation. If we take it on, we can create a future as grand and magnificent in its prospects compared to our current global society as it is in comparison to that of our ancestral tribes huddled in their caves in a small part of East Africa. From the standpoint of that future, nothing else being done today is of remotely comparable importance. Our time will be remembered because this is when humans first set sail for other worlds.

The task for our time is to open the way to Type II. But we should understand where the road leads. We are bound for the stars.

Columbus dared the Atlantic in small, frail coastal craft that, even fifty years later, no one would have attempted to use to cross the ocean. This was how it had to be. Until European civilization became transatlantic, there was no cause to develop truly Atlantic-capable vessels. But once Europeans found their New World, soon enough they developed reliable three-masted caravels, then clipper ships, steamships, ocean liners, and Boeing 747s.

Similarly, the first explorers will make their six-month voyages to Mars in small, cramped vessels, demonstrating a toughness that will be a source of awe to their grandchildren, who will do their three-week interplanetary transits in style aboard well-appointed fusion-powered spaceliners. But the same technology that makes travel to Mars a matter of ease and comfort for everyone will make it possible for those with the bravest spirits to venture much further.

A century ago, the Russian space visionary Konstantin Tsiolkovsky famously said, “The Earth is the cradle of mankind, but one cannot live in the cradle forever.”1 Indeed. The Earth has been our cradle, within which we have developed the capability to enter the solar system, which shall be our schoolyard. There we shall grow bigger, stronger, smarter, wiser, and braver, preparing us to enter the universe at large.

So we will continue to move out.

THE YEAR 2069

As I write these lines, the fiftieth anniversary of the Apollo moon landing is coming into view. Over the past fifty years, our robotic planetary program has performed epic deeds of exploration, while our human spaceflight effort has stagnated. But now, with the entrepreneurial space launch revolution, we are poised to break out into the solar system. If we seize this opportunity, where might we be fifty years hence?

Here is my vision of where we could be. We will have fusion power and open-sea mariculture and will no longer be living in fear of climate change, resource exhaustion, or each other. We will be a cosmopolitan civilization, able to travel the globe freely through suborbital space in less than an hour, so that nearly everyone will have friends in every land. We will have research laboratories, industries, and hotels on orbit. We will have scientific bases, astronomical interferometers, and helium-3 mines on the moon. There will be operational lunar skyhooks, enabling transport all over the moon, and the cheap lifting of propellant to lunar orbit to support exploration missions to the outer solar system. We will have city-states on Mars—vibrant optimistic centers of invention, sporting lively and novel cultures, with many casting off the chains of tradition to strike out new paths to show the way to a better future. We will have mining and settlement outfits finding their way into the main asteroid belt, and exploration expeditions to the outer solar system to test the means by which we might access its enormous energy resources for the human future. We will have grand observatories floating in free space that will be making magnificent discoveries in physics and cosmology, mapping the planets of millions of stars, and finding other worlds filled with life and intelligence. We will be learning the truth about the nature of the universe, and life's role in it, and preparing our first interstellar spaceships to journey forth and find our place among the stars.

This is what we can do, we who are alive today. This is the future we can make. This is the grand heritage that we can pass on to those who will go further.

And then?

TWELVE THOUSAND BY 3000

Ultimate limits are impossible to even conceive, let alone predict. So let's adopt as our time horizon for the future a date a thousand years hence. What might human civilization be like in the year 3000?

Virtually any projection made across such a span of time will no doubt prove to be radically conservative. No one from two centuries ago, let alone ten, could possibly anticipate—or even believe if he or she were told—the everyday features of our civilization today, including as it does thousands of giant ships hurtling through the air at 500 miles per hour and instantaneous communication around the globe. Even a few centuries from now, our present ideas about future spaceflight will probably appear far more quaint than those of the best nineteenth-century visionaries do to us today. Writing in 1865, Jules Verne told how humans could go to the moon.2 He predicted that it would be Americans who would do it; that they would launch from Florida; and that the crew would consist of three men, who would travel in a capsule, orbit the moon, land in the Pacific Ocean, and be picked up by a US Navy warship, all as actually happened 104 years later. But the propulsion system he employed was heavy artillery. This was perhaps a natural mistake for him to make, because big guns were the most potent instruments of his time. But it was wrong, not only because of technicalities concerning the performance limits of artillery propellants and acceptable g-loads for crew, but for the more fundamental reason that he was a nineteenth-century mind grappling with a twentieth-century problem. Similarly, we today can talk about interstellar settlement using fusion-powered spacecraft delivering colonists who terraform planets by building fluorocarbon factories, because such technologies are within our engineering horizon. But we are twenty-first-century minds (I'm actually a twentieth-century mind) dealing with a twenty-third-century problem. If this book survives the ages, readers in the Tau Ceti system several centuries from now may remark how insightful it was for someone living in such a primitive time as ours to foresee interstellar colonization. “But doing it with thermonuclear interstellar spaceships and greenhouse gas factories,” they might say, “how twentieth-century can you get? Of course, they couldn't imagine that we would do it using laser-projected self-replicating nanomachines and programmable microbes….”

While we can imagine such possibilities, we can imagine magic too. If we are to stay within the world of speculative engineering, as opposed to science fiction or fantasy, we need to stay within science as it is known today, even if that necessarily means that we will wildly underpredict the possibilities.

Well then, using fusion-powered spacecraft, spacecraft speeds of 5–10 percent the speed of light seem achievable. If we embrace the Noah's Ark Egg concept, or something like it, then 20 percent light speed could be in reach. In our region of the galaxy, stars are typically spaced about six light-years apart, with a density of about one every three hundred cubic light-years. So allowing a century for a twenty-light-year expansion step and another century to develop the new frontier planet to the point where it becomes the launching point for the next move, it would appear that the velocity of our settlement wave could potentially reach something on the order of 10 percent the speed of light. This being so, then a thousand years from now, human civilization could encompass a sphere a hundred light-years in radius surrounding the Earth. Within this zone, there are twelve thousand stars.

What might we do with twelve thousand stars?

In our neighborhood of the galaxy, about 3 percent of them are likely to be bright yellow-white type F stars, 7.5 percent sunlike type G stars, 12 percent type K orange dwarfs, and 76 percent smaller type M dwarfs. All will have habitable zones, near or far, depending on the brightness of the star. Nearly all are likely to have at least several planets, accompanied by scores of moons and innumerable asteroids.

The majority of the planets or moons found in the habitable zones probably won't be ideal places for settlement when first encountered. But a civilization capable of interstellar flight will be more than capable of terraforming. Based on our experience terraforming Mars, Venus, the asteroids, and the moons of the outer planets, we will move out and make dead worlds come alive wherever we go. We will seed thousands of new created worlds with fabulous arrays of new species. We will advance and multiplex evolution. We will turn geospheres into biospheres, and biospheres into noospheres.3 We will found twelve thousand new branches of human civilization.

What will they be like? Unquestionably, they will be very technologically advanced. Inventions are cumulative, and inventions made anywhere ultimately benefit everyone everywhere. Assuming an average population of ten billion people per solar system, with typical living standards and levels of education greatly exceeding anything seen today, humanity's inventive force will number in the tens of trillions and produce staggering results. With thousands of unique civilizations contributing and exchanging their discoveries via interstellar radio transmission, an immense storehouse of knowledge will be created, advancing and expanding at a stupendous rate. We will plumb the secrets of nature. We will find the cures to all diseases and infirmities. We will improve ourselves. We will become different, in innumerable different ways.

This is a very good thing, because it is essential that humanity become more diverse.

In the twenty-first century, with the advent of global communications, jet aircraft, and, soon, rocket planes, the potential for terrestrial geographic barriers to maintain cultural diversity is in the process of being eradicated. In consequence, the world is now rapidly being homogenized to a single culture, and this tendency will only accelerate. Were we to remain earthbound, we would soon not be only one species but one culture. If studies of biology and evolution are any guide, that is a prescription for disaster.

However, fortunately, the same general level of technology that makes the Earth too small to maintain human diversity is now opening up a much wider sphere for our development. This should generate conditions for the rapid regeneration of both cultural and biological diversity, across a vastly broader theater of possibilities. In nature, large interconnected gene pools are very slow to evolve, as it takes a very long time for any new trait to become dominant. In contrast, the generation of new species is favored when a small group becomes isolated from the main stock of its kind and put in a new environment where it is subject to novel, adaptive stresses. Under such conditions, the generation of new traits is called forth, and since the genes for the new trait are not being constantly washed out by interbreeding with the primary population, new varieties and new species rapidly result. Analogous processes of innovation-in-isolation are necessary for the generation of substantially new cultures by human populations.

As humans expand to Mars, the asteroids, the outer solar system, and ultimately the stars, precisely such conditions for first cultural and, ultimately, genetic diversification will be obtained. Culture will change first, then language.

Among the first things that will change will be forms of political organization. Despite all the progress that has been made over centuries of struggle, it is apparent that the well of human thought on the best forms of social organization has not been exhausted by the present age. We still have a long way to go before we create just societies that truly maximize the human potential of every individual. Even the most advanced Western nations still have a class system, using requirements for expensive university degrees or other certifications as poll taxes to deny access to professions to those who would be kept down. We keep millions in prisons, artificial hells that we, with fabulous dishonesty, label “correctional institutions.” Our educational system has created universal literacy, but at a low level, and is hostile to creativity. Popular culture is a degraded mess. We spend far too much on war and too little on science. Our legal system protects the strong but does poorly for the weak. Political power is divided between a corrupt political class, an arrogant bureaucracy, and a small group of the superrich. We can certainly do better.

There is no consensus on how these problems can be solved. But as humanity moves out into the solar system, those with new ideas on how we might do better will have a chance to give their diverse beliefs a try. This opportunity to be the maker of one's world, instead of a mere inhabitant of one already made, is a fundamental form of human freedom, and people are sure to seize it once it becomes available. So, Type II will see the establishment of many new branches of human civilization on the moon, Mars, the asteroids, the satellites of the outer planets, and even the Kuiper Belt, organized in accordance with myriads of divergent social and political concepts. Most of the truly novel ones may fail because, for the most part, things are done now the way they are done for a reason. Tyrannies will fail, as they always do. But some of the new worlds will find a better way to maximize human potential. These will draw immigrants, prosper, grow, expand, and then be emulated by others, as a result. In this way, interplanetary diversity will lead to social progress.

After a period of such diverse experimental development, a Type II civilization might ultimately become politically unified, but a Type III civilization cannot. The distances between the stars are simply too great for any sort of enforcement. So there will never be an interstellar empire. Rather, there will be a vast and expanding collection of Type II city-states, diverging in culture, social, and political organization, but trading thoughts, and learning from the successes or failures of each.

While all the major languages on Earth have a recognizable history going back millennia, they have changed a lot. Many people today have trouble with the English of Shakespeare, and few can understand that of Chaucer—who wrote a mere seven hundred years ago—without university training. The English may owe their existence as a nation to Alfred the Great, but they can no longer understand him. So there will be new languages—thousands of them—new literatures, and new poetry.

But things will likely go much further. Due to the intrinsic enormous differences in environment from one extraterrestrial habitat to another (down to things as fundamental as the gravitational field within which a civilization exists), it is certain that not only culture but heredity will be driven fast and hard in many diverse directions.

It might be maintained that in the future, the increasing human ability to control heredity will impede this process. I would argue the contrary. In fact, since cultural evolution occurs normally on a much faster timescale than genetic evolution, as soon as human beings gain control of the genetic code—that is, culture gains control of heredity—biological evolution will occur at a greatly accelerated pace. It might be the case that in one locality or another, governments will act to suppress this kind of self-directed evolution. However, enforcement of any sort of government edicts across interstellar space is likely to be impossible. Therefore, among the culturally diverse civilizations, some might choose to suppress change, but others will drive it. The difference of opinion on this score will thus only serve to accelerate the process of multiple speciation.

One of the results of these programs of self-modification will no doubt be a drastic extension of the individual human life span. The aging process itself may well be defeated. If that is the case, however, the necessity for space expansion will be greatly accentuated, as the younger generation will face old worlds in which the determining roles have already been assigned. Humans need to matter. In the age of quasi-immortality, new generations will need new worlds to give their lives immortal purpose. Fortunately, long-lived people will be able to undertake long voyages. Thus the interstellar diaspora, and its production of ever more diversity, will be driven even further.

In science fiction television and film, such as Star Trek, the galaxy is frequently depicted as being inhabited by numerous species of “aliens” who are humanoid in all respects except for minor differences, such as skin color or ear shape, and who can sometimes interbreed. Humans are the product of four billion years of terrestrial evolution, and while for reasons of convergent evolution, it is possible that aliens might be found with a general form similar to humans (i.e., two arms/two legs/head on top is a fairly practical design plan), they would obviously differ enormously from us internally at every level, including organs, tissues, and cellular structure. Interbreeding would thus be clearly an impossibility. However, if the process of human diversification alluded to in the previous paragraph were to go forward, then it is highly probable that a thousand years from now, interstellar space in this region of the galaxy will be populated by numerous human-descended intelligent species that will differ from each other in appearance, emotional makeup, and other characteristics to a considerably greater extent than the cosmopolitan species that populate the Star Trek universe. Local stylistic fads could well create races with green skin or pointed ears; more serious considerations such as gravity differences might drive the development of outlandishly tall-thin (low gravity) or short-powerful (high gravity) varieties. Many of them, as a result of their self-directed evolution, will be far more intelligent, sensitive, healthy, long-lived, athletic, graceful, and (to themselves, anyway) beautiful than we.

But, in their own way, they will all be human.

Eventually, however, we will meet people who aren't. This is so because, as we discussed earlier, the fraction of biospheres sporting civilizations is likely to be given by the ratio of the lifetime of a species-civilization to the time it takes a mature biosphere to generate an intelligent species. We have limited data to judge this, but going on the basis of the experience of our own planet, this is likely to be on the order of one in a thousand. So, as humanity expands to tens of thousands of solar systems, the probability of direct contact with alien civilizations will increase to near certainty.

What then? Might they not be more advanced than us?

They certainly might. But I think we'll be fine regardless. While alien invasions are a staple of science fiction, the logistics of interstellar warfare provide enormous advantages to the defense, as the home team is likely to outnumber the visitors by millions to one. Provided they have attained a minimally competent Type II status, the defenders would almost certainly be able to vastly outgun any invading force as well.

But there will be no war between starfarers, because no species will ever be able to make it to Type III without understanding the universal beneficial role of creative intelligence.

It is intelligence that creates resources. The more creators, the more resources.

If they are wise enough to avoid destroying themselves while possessing Type II technologies, they'll be wise enough to know that. The same will be true of us.

So I believe we will meet them as friends, and their friends as well, with great benefit to all as the circle expands, as each will be able to acquire from the rest not only vast knowledge but entirely new ways of understanding.

Perhaps there already is such a Galactic Club. If so, we need to prepare ourselves to join it. If not, we need to prepare ourselves to start it.

Type III calls.

CONCLUSION

Our distant kin followed the stars to the north. Later, as humans became seafaring, it was the stars again—with poetic truth, the North Star—that gave us the guidance we needed to become a truly global species.

Today the stars beckon again, this time not to new continents but to new solar systems. Multitudes of new worlds yet unknown await, filled with menaces to be faced, challenges to be overcome, wonders to be discovered, and history to be made. The first chapter of the human saga has been written, but vast volumes lying out among the stars are still blank—ready for the pens of new peoples with new thoughts, new tongues, astonishing creations, and epic deeds.

It is a grand time to be alive. We are young, the universe is in its spring, and the door has been opened, inviting us outside to meet the dawn of the greatest adventure ever.

Ad Astra.