We are accustomed to the concept of colonising the solar system and populating the universe. We think of it as a project for the distant future but perhaps we should be getting on with it. I offer three reasons, any of which might suffice, for us to begin space colonisation:
- material necessity,
- psychological need,
First I argue that limited resources will not allow humans to live on Earth forever. Then I argue we lack purpose and must move on. Lastly I argue that space colonisation is an imperative of the universe itself.
Material necessity. Our technological culture uses the planet’s non-renewable raw materials and pollutes its ecosystems. Eventually capacities will run down. They may be running down already: our attempts to limit population and recycle resources indicate we are not as rich as we used to think. Total recycling is impossible so conservation postpones, rather than solves, the resources and pollution problems. At some stage we have to leave Earth if we are to maintain our technological civilisation.
We may have reached that stage. After hundreds of thousands of years of starvation, war and disease, modern “developed” societies reached the approximate human potential of health, comfort, security and liberty. This has been achieved for twenty percent of mankind for half a century and the Earth—land, sea and air—is indicating it can’t cope. Can it support this standard of living, expanded to the other eighty percent, for centuries?
Earth’s dwindling resources might be supplemented with imports of material and energy from space but one-way transfers would further stress the environment. Apparently, the surface of a planet is not a suitable habitat for a technological civilisation. Though some people will always live on Earth and some may live on other planet surfaces, if our species is to flourish and expand to trillions, it must mostly live in space. This would allow Earth to be renovated and restored.
If Earth-based economic resources have peaked and are running down, we should be treating them as investment capital. They should not be dissipated propping up a few more generations of Earth’s wealthy but should be invested in space colonisation which offers prosperity forever and hope of prosperity to everyone. If we have outgrown the planet our priority should be to leave it. Leaving will be expensive and if we wait till resources are exhausted we won’t be able to afford it.
In space, the supply of material and energy is infinite and artificial nuclear energy may be safely employed. The prospect is of boundless wealth. In space there are no limits to growth.
The outlay to establish the first space cities would be a substantial fraction of our civilisation’s current assets. It may exceed the expenditure on the twentieth century wars and arms races. The cost arises because the technology and biology have to be lifted against Earth’s gravity. Actual construction materials could mostly come from the moon. The mine on the moon might itself cost more than any previous construction project but the cost of launching material from the moon would be lower than from Earth. The first cities could be built at the “Lagrange points” (places where gravity balances out) synchronous with the moon’s orbit around the Earth. They would have to be wheel- or cylinder-shaped vessels rotating to simulate gravity. We should expect it to take a generation or two for the first colonies to become economically viable and possibly centuries before they become substantially independent of Earth-based infrastructure.
The difficulties of arranging for millions to migrate and live in space are daunting but have to be faced. In the end, there is no alternative. If humanity as a whole is maintaining its wealth or becoming wealthier, then we can afford to put it off but if we are now getting poorer in overall terms then we must start the departure. If we don’t act while we are rich, we won’t succeed. If we don’t succeed, the drawn-out death convulsions of our civilisation will not only reduce humans to wretchedness but will also destroy Earth’s ecology and exterminate many animals and plants. If we succeed, the biological potential is unlimited.
Psychological need. Material limits are not the only pressure. In addition to resource shortage and ecosystem stress, we face psychological pressure. Humans are not content just to be born, to exist, and to die. We differ from other social animals in that we seek some purpose to life other than status advancement and procreation.
What do people dream of? What engages them and demands commitment? The days of the explorers and frontier settlers are long gone. The various experimental utopias are now historical curiosities. The old universal incentives of serving gods and ensuring life after death have vanished. Government which relies on a minority coercing the majority is neither stable nor competitive. Tribalism is a dead end and the ideological alternatives of fascism and communism have been seen to fail. So secular democracy the only workable system of government. In it soldiering is in disrepute (there being no cultural threat to guard against) and nationalism conflicts with free trade. Static populations, economic stagnation and wealth itself have made “nation-building” sound quaint. There is nowhere to go.
Nowhere to go except to decay. The developed countries are marking time. Their development stopped over a generation ago. They have little potential for improvement and much potential for trouble: unemployment, depression, dysfunctional families, addiction, suicide, crime, political extremism, terrorism. What is there to look forward to? A better shopping experience? Exciting food and fashions? Fancier phones? Our societies live from year to year with no vision and no plan except to react to the next problem. We no longer expect children will live better than their parents. Despite an unprecedented range of entertainments, modern society is predictable and dull. Where is purpose, ambition, adventure and excitement? In commerce? In an occupation? There can be dignity in making a living but that which actually distinguishes humans from other creatures—wonder, exaltation, glory—has nothing to do with providing food and shelter. The only echo of that nowadays is in extreme sports.
But departure from Earth is more than a way to save us from boredom; it is the ultimate test of Darwinian fitness. Can the species bequeath its descendants the opportunity of worth-while lives, children without limit, and inexhaustible wealth and power? As a human enterprise, space colonisation would fuel dreams forever.
Destiny. Moving into space has implications transcending our resources, our dreams, our species. After four billion years of evolving life, this is the first chance to escape which Earth’s progeny have had; humans would not go alone: thousands, or millions, of other organisms would accompany us.
As far as we know it is also the universe’s first chance. Unless intelligent life arises elsewhere, it will be the universe’s only chance. In that case, if our technological culture is in decline, then this moment—a few decades—is the only opportunity the universe has to become conscious. A few decades among the unimaginable billions of past and future years. This may be a pivotal moment, not just for humanity and for Earth, but for the cosmos.
Although we evolved on Earth we do not necessarily belong to it. We can distinguish three great events, or advents, in our origins: time, life and mind. Fourteen billion years ago time began; matter and energy came into existence and the universe blazed and cooled, smelting chemical elements in accordance with the laws of physics. The second event occurred four billion years ago when circumstances on one planet gave rise to self-replicating carbon molecules. Life—complex, energy-driven interactions of the chemical elements—occupied and moulded the surface of the Earth. Recently—a mere million years ago—life gave rise to mind, a mysterious new power operating within the old laws of carbon life and of physics. With mind the universe began to understand itself and in the last two hundred years mind has become, via technology, a significant force on Earth’s surface.
Whether or not life and mind spread through the universe is up to us. It could be that intelligence has flowered and withered on other planets, perhaps with wistful inhabitants impotent before insoluble engineering problems. The technical feasibility of escaping the home planet depends on circumstances. Our departure is facilitated by the modest size of Earth, by its dense atmosphere, and by the lucky size and position of our moon which provides stable Lagrange points as stepping stones. We have no insurmountable physical obstacles.
If we fail it will be our own fault. The obstacle is politics. The start capital is far beyond private initiative. The USA, which might have the strength, appears to be getting poorer and to have lost interest in space. The United Nations has no relevant charter. It seems we would need a new supranational organisation with unprecedented authority. Humanity’s greatest task confronts us; if we live ten billion years and spread to the ends of creation, we will never face another mission so crucial. Yet—how many politicians have even heard of it?
The human species, carrier of the intelligence of the universe, may have already arrived at the fork in the road. We must pay a toll to take the high road but it leads to unbounded prosperity. The low road is easier but leads ultimately to oblivion. The danger is that by the time it becomes obvious that the shadows are deepening, turning around might be impossible.
The outlook for the Earth’s teeming humans is sombre: increasing social and material struggle in the wealthy countries and elsewhere billions in poverty. Is that also the long-term outlook? If it is, and if we don’t start our departure soon, we will condemn our species to acrimonious extinction—and to the bitter realisation that we had our chance and missed it and lost everything.
If we succeed in leaving we will have galaxies at our disposal and we will never die.