We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not a subscriber? Subscribe now for unlimited access to online articles.

View from the Marketplace

Views from the Marketplace are paid for by advertisers and select partners of MIT Technology Review.

Interstellar travel and post-humans

The stupendous time-spans of the evolutionary past are now part of common culture.

Our Sun is less than half way through its life. It formed 4.5 billion years ago, but it has got six billion more before the fuel runs out. It will then flare up, vaporizing any life that might still remain on Earth. Any creatures witnessing the Sun’s demise six billion years hence will not be human‑they will be as different from us as we are from a bug.

Post-human evolution could be as prolonged as the Darwinian evolution that has led to us, but at the much accelerated rate allowed by genetic modification and the advance of machine intelligence. However this century may be a defining moment. We humans are entitled to feel uniquely significant, as the first known species with the power and the responsibility to mold its own future —and perhaps the future of intelligence in the cosmos. Three new technologies will be crucial in the rest of this century: advanced biotech, artificial intelligence and the ability to explore space.

Interstellar Travel and Post-Humans

By 2100 courageous pioneers may have established “bases” independent from the Earth but do not ever expect mass emigration from Earth. It is a dangerous delusion to think that space offers an escape from Earth’s problems. There is no “Planet B” and space is an inherently hostile environment for humans. For that reason, even though we may wish to regulate genetic and cyborg technology on Earth, we should surely wish the space pioneers good luck in using all such techniques to adapt to different atmospheres, different g-forces, and so on. This might be the first step toward divergence into a new species: the beginning of the post-human era.

But are we unique, or is there intelligent life out there already? There may be simple organisms on Mars or in the ice-covered oceans of Jupiter’s moon Europa but few would bet on it; and certainly nobody expects a complex biosphere in such locations. For that, we must look to the distant stars and here the prospects are far brighter: we have recognized that there are, within our Milky Way Galaxy, millions of planets resembling the young Earth. But do we expect alien life on these extra-solar planets? Conjectures about advanced or intelligent life are, of course, far shakier than those about simple life.

Perhaps the Galaxy already teems with advanced life, and our descendants will “plug in” to a galactic community —as rather “junior members.” On the other hand, our Earth may be unique and the searches may fail. This would disappoint the searchers. But it would have an upside. Humans could then be less cosmically modest. Our tiny planet could be the most important place in the entire cosmos. Moreover, we would be living at a unique time in our planet’s history: our species would have cosmic significance, for being the transient precursor to a culture dominated by machines, extending deep into the future and spreading far beyond Earth.

Interstellar travel is inherently of long duration, and is, therefore, an enterprise for post-humans, evolved from our species not via natural selection but by design. The first voyagers to the stars will not be human, and maybe not even organic. Evolution is just beginning. Intelligent entities—descended from Earthly life—could spread through the entire Galaxy, evolving into a teeming complexity far beyond what we can even conceive.

And that is not all: there is a final disconcerting twist. Post-human intelligence will develop hyper-computers with the processing power to simulate living things —even entire worlds as complex as the one we perceive ourselves to be in. Maybe these kinds of superintelligences already exist elsewhere in the multiverse. What would these superintelligences do with their hyper-computers? They could create virtual universes vastly outnumbering the “real” ones. So perhaps we are “artificial life” in a virtual universe. This concept opens up the possibility of a new kind of “virtual time travel,” because the advanced beings creating the simulation can, in effect, rerun the past.

Possibilities once in the realms of science fiction have shifted into serious scientific debate. From the very first moments of the big bang to the mind-blowing possibilities for alien life, parallel universes, and beyond, scientists are led to worlds even weirder than most fiction writers envisage. It is remarkable that our brains, which have changed little since our ancestors roamed the African savannah, have allowed us to understand the counter-intuitive worlds of the quantum and the cosmos. But there is no reason to think that our comprehension is matched to an understanding of all key features of reality. If our remote descendants reach the stars, they will surely far surpass us not only in lifespan, but in insight as well as technology.

 Read the full article here.

Tech Obsessive?
Become an Insider to get the story behind the story — and before anyone else.

Subscribe today
More from Sustainable Energy

Can we sustainably provide food, water, and energy to a growing population during a climate crisis?

Want more award-winning journalism? Subscribe to Print + All Access Digital.
  • Print + All Access Digital {! insider.prices.print_digital !}*

    {! insider.display.menuOptionsLabel !}

    The best of MIT Technology Review in print and online, plus unlimited access to our online archive, an ad-free web experience, discounts to MIT Technology Review events, and The Download delivered to your email in-box each weekday.

    See details+

    12-month subscription

    Unlimited access to all our daily online news and feature stories

    6 bi-monthly issues of print + digital magazine

    10% discount to MIT Technology Review events

    Access to entire PDF magazine archive dating back to 1899

    Ad-free website experience

    The Download: newsletter delivery each weekday to your inbox

    The MIT Technology Review App

You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.