Distant ruins

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Distant ruins

'When interstellar archaeologists tilt their telescopes to the sky, they are gazing into the deep history of the cosmos, but to find a civilization more advanced than ours, they have to tilt their imaginations into the future'. Photo courtesy W. M. Keck Observatory, Hawaii

Scientists used to scan the skies for messages from alien civilisations. Now they go looking for their ruins

Paul Gilster is a full-time writer on aerospace and technology topics whose site, Centauri Dreams, chronicles ongoing research into interstellar flight.

2900 2,900 words
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‘Look on my works, ye Mighty, and despair!’ says Ozymandias’s ruined statue in the desert of Shelley’s imagination. Shelley’s sonnet is often interpreted as a sober warning that human works are fleeting, but when I read it as a young boy it kindled a sense of adventure; it suggested a wonderfully mysterious past beneath my familiar suburban surroundings. As a child, I was obsessed with archaeology, the attempt to understand the past through enigmatic remains. I spent many afternoons digging up dark patches of Midwestern soil, as I searched the region’s dense forests for artefacts of the Mississippian Indian cultures. I never found a lost city, but I occasionally turned up an arrowhead that would set me speculating about its owner and how it was lost. Through archaeology, I came to see landscapes as temporary surfaces that concealed a deep history. The world became rich with hidden texts.

Boyhood obsessions often linger into adulthood, even if they aren’t immediately recognisable. These days I find myself looking up into the Milky Way’s majestic thread, wondering if its stars play host to monuments as haunting as those found in Egypt’s Valley of the Kings. The natural sciences tell us that time is deep, and that civilisations could have arisen well before the Earth formed. Today, a small group of interstellar archaeologists is looking for evidence of those civilisations. They are tantalised by the possibility that the universe is not just a birthplace of alien cultures but also their necropolis.

We use the word ‘archaeology’ to describe this effort, because looking into deep space takes us deep into the past. The photons that strike our telescopes’ detectors take time to reach us: the light of Alpha Centauri, the nearest stellar system, is 4.3 years old when it arrives. It travels at 300,000 kilometres per second but has to cross 40 trillion kilometres to get here. Dig gradually into the soil and you push through layers accreted by wind, rain, construction, and flood. Dig deep into the sky, beyond local stars such as Alpha Centauri, and you push the clock back with the same inexorability. Epsilon Eridani, another nearby star, is seen as it was over 10 years ago. Light from the fascinating Gliese 667C, a red dwarf with three planets in its habitable zone, takes 22 years to make the journey.

In the cosmic scheme of things, these are trivial distances. Our green and blue world circles its star some 27,000 light years from the galactic centre. The glow we see at the Milky Way’s core began its voyage towards us at a time when prehistoric hunters were chasing mammoths across Europe’s ice sheets. The galaxy itself spans 100,000 light years, and its nearest equivalent, the great disc of Andromeda, is 2.5 million light years away. We see it as it looked when humanity’s ancestors walked the African savannah. When interstellar archaeologists tilt their telescopes to the sky, they are gazing into the deep history of the cosmos, but to find a civilisation more advanced than ours, they have to tilt their imaginations into the future. They have to plot out a plausible destiny for humanity, and then go looking for it in the cosmic past.

If we can so easily misinterpret our own past, how might we misconstrue the artefacts of a truly alien culture?

Conventional archaeology has shown us how difficult it is to make guesses about civilisations across time. In the late 19th century, the excavation of Hisarlik, the site in Turkey now thought to be the location of ancient Troy, soared into the European imagination through the work of Heinrich Schliemann. Legend has it that the wealthy amateur sent a cable that prematurely proclaimed: ‘I have looked upon the face of Agamemnon.’ It is not clear that he actually used those words, but we do know Schliemann’s work enchanted the salons of Europe, a continent that was besotted with the mysteries of a deeply romanticised past.

But Schliemann was hardly a professional scientist. He had made his fortune as an indigo merchant, export agent and commodities speculator before succumbing to a growing passion for all things Mycenaean. When he got to Hisarlik, he and his team unwittingly dug straight through the layer now thought to have been Homer’s Troy, compromising much of that stratum for later investigation, while uncovering decorative objects from between 300 and 500 years earlier — objects that Schliemann’s wife, a Helen in the Victorian fashion, wore when out on the town.

If we can so easily misinterpret our own past, how might we misconstrue the artefacts of a truly alien culture? One can only wonder if a modern-day Schliemann, armed with telescope or radio dish, and freighted with myriad assumptions, might not blunder away an equally enigmatic interstellar find. Interstellar archaeologists are looking for evidence of engineering on scales that dwarf our own. They assume that civilisations eventually build technologies capable of exploiting the energy resources of entire stars. They are building on the early work of the Soviet astronomer Nikolai Kardashev, who, in 1964, set about categorising these futuristic civilisations. His scheme, called the Kardashev Scale, has three types, and so far humanity does not even rate as a Type I — a civilisation that can master the energy resources of its entire planet. A Type II culture can tap all the resources of its local star, and a Type III can harness the energy of an entire galaxy. We do not, of course, know if any civilisation other than our own exists, but Kardashev’s scale offers us a way of approaching the problem of detection: it gets us thinking about what kind of traces these advanced civilisations might leave behind.

Imagining the engineering of ancient extraterrestrials is difficult work, foolhardy even. The earliest attempts to do it tended to focus on the largest conceivable structures. The former Fermilab scientist Richard Carrigan, one of interstellar archaeology’s pioneers, has long been a vocal proponent of the hunt for Dyson spheres, a technology proposed by Freeman Dyson in 1960. Dyson predicted that energy-seeking civilisations would surround their home stars in a technological shell, or a swarm of spacecraft, in order to capture its energy. A sphere with the radius of Earth’s orbit would have an interior surface area 100 million times as large as the surface area of our planet. In 1966, Carl Sagan suggested that such spheres might be detectable, but he cautioned that they would be hard to distinguish from natural objects that gave off a similar infrared signature. Decades later, Carrigan would tell New Scientist that he wanted to try anyway, that he ‘wanted to get into the mode of the British Museum, to go and look for artefacts’.

True to his word, Carrigan has conducted a series of searches for Dyson spheres, following earlier work by the Russian astronomers Vyacheslav Ivanovich Slysh and MY Timofeev. Carrigan combed IRAS, the infrared sky survey that dates back to the 1980s, looking for the distinct infrared signatures calculated for this purely theoretical technology. More recently, Berkeley’s well known exoplanet hunter Geoff Marcy began studying 1,000 Milky Way star systems for evidence of large structures, looking for visible disturbances in light levels around the parent star as the techno-structures transit between their star and the Earth. At Penn State, Jason Wright and his colleagues Matthew Povich and Steinn Sigurðsson are pushing the search for Dyson spheres deeper into the galaxy, and even beyond it, by examining infrared data from the Wide-field Infrared Survey Explorer (WISE) and the Spitzer Space Telescope. Wright’s group is also looking for ‘Fermi bubbles’, patches of a galaxy that show higher infrared emissions than the rest, which could be a sign that a civilisation is gradually transforming a galaxy as it works its way across it. M51, the ‘Whirlpool’ galaxy, offers a good field for study, because it is turned so that we see it face-on.

In the age of big data, it is possible that evidence of an extraterrestrial civilisation is already hiding in our archives

None of the ongoing interstellar archaeology searches will be easy to confirm, supposing they find something notable, for natural explanations for such phenomena abound. For one, spiral galaxies already contain voids that can mimic a civilisation’s spread. The galaxy VIRGOHI21 is a good example. At optical wavelengths, it’s dark enough to suggest it might be a candidate for Dyson-style engineering. But HI21 is also explained through the effects of so-called ‘tidal shredding’, a natural process that may be producing the same signature. Dyson sphere signatures are trickier still: they could be nothing more than stars enshrouded in dust clouds. Positive results turned up by interstellar archaeologists will need plenty of scrutiny.

The field’s deeper thinkers are starting to wonder if there might be other ways to search. Milan Ćirković, from the Astronomical Observatory of Belgrade, has suggested we go after large artificial objects in transiting orbits. He says we ought to look for something like the huge space colonies once championed by Gerard O’Neill, structures that could be involved in large-scale industrial operations, which might be furnaces for antimatter. If so, their existence could be confirmed by the detection of unusual gamma ray signatures. Alien engineers might even manipulate their own central star. In 1957, Fritz Zwicky suggested that civilisations could fire fuel pellets into their local stars, to move their solar systems to new locations, especially when interstellar dangers loomed. Forty years later, the physicist Leonid Shkadov suggested that huge spherical mirrors could be built to accomplish the same thing, by creating a feedback effect from the star’s radiation, that would let its creators control the star’s trajectory through the galaxy.

Interstellar archaeologists are forced to wonder what structures like these might look like from a distance of thousands or tens of thousands of light years. Fortunately, they can tinker with different signatures, because we already have a vast trove of star data to trawl. With detailed information on billions of systems sitting on our servers, and processing power whose growth shows no signs of slowing, we can tune our algorithms to search for transit signatures that could flag engineering projects of immense scale. In the age of big data, it is possible that evidence of an extraterrestrial civilisation is already hiding in our archives.

Our searches might even turn up a galactic gravestone, a monument meant to record the wonders of a dying civilisation for posterity. Luc Arnold from the Aix Marseilles Université has suggested that distant civilisations might use planet-sized objects as deliberate celestial signs, knowing that their signature could be readily detected by alien astronomers. Such objects might be the final act of a civilisation in its death throes, left behind as a legacy to surviving cultures. The astronomer Charles Lineweaver has pointed out that most of our galaxy’s terrestrial-class worlds are two billion years older than Earth. How many civilisations have flourished and died out in that time?

Of course the search for the remnants of these civilisations need not stop with unusual light signatures. In addition to energy, an ancient spacefaring culture would need large amounts of raw material to build its structures. Working with Martin Elvis of the Harvard Smithsonian Center for Astrophysics, the astronomer Duncan Forgan has investigated the possibility that the debris discs around other stars could show signs of large-scale asteroid mining. Rock and ice debris is concentrated in our own solar system at various distances, from the main-belt asteroids between Mars and Jupiter to the Kuiper Belt and the still more distant Oort Cloud. And we now have unambiguous evidence of similar discs of debris around stars such as Vega, Fomalhaut and Beta Pictoris.

Beech thinks blue straggler stars could mark a Kardashev Type II culture trying to preserve its habitat.

Asteroid mining could show up in our telescopes as chemical imbalances in these discs. If we were to see a sharp depletion of elements like iron and nickel, or rare elements, such as platinum and palladium, that might flag extraterrestrial mining operations. The dynamics of the debris disc itself would likewise be affected, as larger objects were broken down for industrial use. The production of dust through mining process might also cause unusual temperature gradients. We don’t have the equipment to make these measurements at present, but future space-based observatories may be able to.

And what of stars that are anomalous such as the ‘blue straggler’ stars that seem much younger than the stars around them? Astronomers are puzzled by them because globular clusters — ancient cities of stars that sit in a spherical halo around the Milky Way — are where blue stragglers were first identified, and these are thought to contain stars that formed at the same time. Now we’re finding blue stragglers in the galactic bulge itself, another unusual place for younger stars since most star formation there has stopped. The giant blue stars we see shining there should have exploded into supernovae billions of years ago.

There are many theories that attempt to explain the blue straggler phenomenon, but only one implicates interstellar archaeology. Martin Beech, an astronomer at the University of Regina in Saskatchewan, has suggested that we consider blue stragglers candidates for follow-up searches to the Search for Extraterrestrial Intelligence (SETI). There are scenarios in which you could imagine a sufficiently advanced civilisation decided to adjust its own star’s ageing process. Pump enough shell hydrogen back into the inner core of a star and you should be able to prolong its lifetime, thus preserving any culture that lives in the vicinity. Beech thinks blue stragglers could mark a Kardashev Type II culture trying to preserve its habitat.

All of these searches ask us to put ourselves in the minds of beings about whom we know absolutely nothing. The physicist David Deutsch has flagged this as a problem for prediction of all kinds, not just those involving SETI. According to Deutsch, we can distinguish between ‘prophecy’ and ‘prediction’, with prophecy being the discussion of things that are not knowable, while prediction deals with conclusions that are based on good explanations of the universe. As prognosticators from Thomas Malthus to the Club of Rome have demonstrated, we may be able to identify problematic trends in the present that can be extended into the future, but we cannot know what knowledge we will acquire in the future to manage those problems. This is why no scientific era has succeeded in imagining its successor. The scientists of the late 19th century discovered this firsthand, when confronted with the emergence of quantum theory and relativity early in the early 20th. Both theories raised questions earlier theorists couldn’t have even formulated.

In the context of interstellar archaeology, the problem is that we have no analogues in our experience for what advanced cultures might create. Patience is the byword as the effort proceeds, the same patience that Heinrich Schliemann’s successors have used to master the art of sifting through rubble, with careful digging and delicate brushwork sweeping aside soil to uncover the shape of a fragmentary artefact. Interstellar archaeologists are tasked with sifting through gigabytes of data, not layers of soil, but the principle is the same. In a recent paper with Robert Bradbury and George Dvorsky, Milan Ćirković offered a paradigm for a new SETI, one that would include not only searches like these but a wide range of ‘future studies’ that would encompass how a post-biological intelligence might emerge and make itself known — intentionally or unintentionally.

This approach asks interstellar archaeologists to expand their field to include the study of computer science, artificial life, evolutionary biology, the philosophy of mind and the evolving science of astrobiology. A successful search for macro-engineering would challenge us to re-imagine our position in the cosmos, confronting us with structures that might identify a living culture, or one long dead. In this respect the interstellar archaeologists are like the Anglo-Saxon and Celtic peoples who inhabited Britain after the end of the Roman occupation. They found themselves living amid engineering that was beyond their own capabilities, a disquieting experience that made its way into Anglo-Saxon poems such as ‘The Ruin’:

The city buildings fell apart, the works
Of giants crumble. Tumbled are the towers
Ruined the roofs, and broken the barred gate,
Frost in the plaster, all the ceilings gape,
Torn and collapsed and eaten up by age.
And grit holds in its grip, the hard embrace
Of earth, the dead-departed master-builders,
Until a hundred generations now
Of people have passed by. Often this wall
Stained red and grey with lichen has stood by
Surviving storms while kingdoms rose and fell.
And now the high curved wall itself has fallen.

Verse like this infuses our past with grandeur while imbuing its artefacts with the rich patina of shared human experience. It serves as a connective tissue between cultures. But no such collective history can illuminate the discoveries of our interstellar archaeologists. Finding the monuments of civilisations more advanced than our own would challenge us to place ourselves in a totally unfamiliar context, as cosmic newcomers who can suddenly aspire to long lifetimes. If we found a lost city in the sky, it might fire our imaginations. It might give us reason to think we’ll outlast existential threats like nuclear weapons and biological terrorism. An interstellar Hisarlik would tell us that some civilisations do survive these dangers and learn to harness immense energies to grow. Rather than despair, we may see their mighty works and rejoice at what we can become.

Read more essays on astronomy, knowledge and space exploration


  • Andrew Crumey

    Thanks for a fascinating article. The mention of Dyson spheres brings to mind another of Dyson's ventures, the Orion Project, which proposed to power rockets by having them eject atomic bombs whose blast would push them forward. In theory it looked like a good, energy-efficient idea - in practice it was an obvious non-starter for envirnomental and political reasons: a reminder that technical feasibility is not enough to ensure practical implementation. I think it was Euler who suggested cutting down vast tracts of Siberian forest to create a right-angled triangle that would be visible to any inhabitants of the Moon...

    As you say, "no scientific era has succeeded in imagining its successor." But as Walter Benjamin said, paraphrasing the historian Michelet, "every age dreams its successor". If we are to imagine the civilisations of other worlds then the prophetic dreams of art may perhaps be as useful to us as the deductions of science.

    • G

      The problem with Dyson spheres/rings, is this:

      Eventually the star blows up.

      Would you rather have a few hundred million times Earth's population wrapped around a star with a finite lifespan, or sprinkled around on planets across a wide swath of space?

      If the latter, then you only have to relocate a few billion people in advance of a stellar catastrophe, which is quite a bit better than having to relocate tens of trillions from one Dyson sphere to another.

      And if I was ET, what I'd do is build solar arrays around multiple stars, using microwave laser to beam energy toward artificial satellites orbiting "rogue" planets constructed in interstellar space. Thus every such planet has three or more stars powering it, and every such planet is out of the way of stellar catastrophes short of supernovae and GRBs. Redundant energy supplies, and as nearly complete safety as possible.

  • Caspar Henderson

    "It was like looking at the ruins of an ancient town, a Moroccan city tens of centuries old, convulsed by an earthquake or some other disaster. I made out a tangled web of winding sidestreets choked with debris, and alleyways which fell abruptly towards the oily foam that floated close to the shore. In the middle distance, great battlements stood intact, sustained by ossified buttresses. There were dark openings in the swollen, sunken walls — traces of windows or loop-holes. The whole of this floating town canted to one side or another like a foundering ship, pitched and turned slowly, and the sun cast continually moving shadows, which crept among the ruined alleys. Now and again a polished surface caught and reflected the light."

    from Solaris by Stanisław Lem

  • mijnheer

    Regarding monuments meant to record the wonders of dying civilizations, I expected the author to mention the short story "The Star" by Arthur C. Clarke -- though the discovery in that case presupposes interstellar travel by humans.

  • lurs700

    Amazing article.We are slowly developing the technical capability to make startling discoveries like the ones described here. Regretfully, important milestones like the PlanetFinder mission were cancelled, the James Webb space telescope was delayed 5 years, and other similar projects in the NASA pipeline are drawing straws to see which one gets cut by reduced funds from sequestration. But of courses, sacrifices had to be made in order to fund 'too-big-to-fail' institutions responsible for the financial collapse, while the middle class was left to cope with the socialised costs. But I disgress; What we learn from ancient civilisations that might or might not be out there for us to detect with out observational technology will teach us a lot about our possible fates. Will we grow up to be space-faring citizens of the galaxy? Are we doomed to repeat the same mistakes that led other cultures to their end?

  • earthoileater

    Am I alone in thinking that all our fantasies of the future are the result of abundant free time provided by our burning of earth's coal and oil? When that energy is gone, we will be using solar energy in its most basic form, plants, and our futuristic considerations will be about where to bed down for the night. We are deluded in thinking that discoveries, once gained, will never be lost. Nothing guaranties that 1000 years from now the intricacies of quantum theory, DNA, cosmology, etc, will still be part of our body of our knowledge. We tend to forget, or at least not talk about, the fact that the modern world will no longer exist when earth's oil is gone. peace.

    • KinglyCitrus

      The most "basic" form of solar energy is that which is emitted directly from a star- infrared, visible, and ultraviolet waves. We have the technology now to harvest this energy. As that technology improves, our capacity to utilize such energy will also improve. Of course, the chemical forms of the sun's energy are the easiest to utilize.

      I don't doubt that nearly every civilization in the Universe has followed and will follow a similar trajectory, utilizing their "fossil fuels" as launching pads to develop more advanced energy technologies. Some of them, undoubtedly, fail. They are not sufficiently smart or lucky to realize the necessity of the eventual transition, either destroying themselves in petty resource wars or falling back into the dust penniless after wasting their three or four-century golden age.

      Fatalism, though, isn't helpful. We can sit around and bemoan the certain exhaustion of our chemical resources, or we can find a way to break our dependence and utilize the incredible energy the Sun produces in other ways. Staying focused is the only way for the species to succeed.

      • G

        You raise an interesting point indirectly.

        Fossil fuels can only be produced when large quantities of biomass can be compressed under rock formations over geological time. The mass extinctions such as of the dinosaurs, have produced the large concentrations of fossil fuels we have today. Now envision a planet that did not have a slate-wiper event at its dinosaur stage, such that intelligent life evolved on a different basis.

        It is possible that intelligent life would have evolved more or less quickly, but in the absence of fossil fuels, it would have to find some other fuel source, and its "booster rocket" stage (to quote a post below) would be radically different. In all likelihood it would have circumvented the risk of causing itself a climate catastrophe, because it would go from burning biomass in realtime, to the recognition of the need for new energy sources in order to avoid stripping all the available biomass.

        From there, the only needed assumption is that physics and chemistry are the same everywhere (in other words, not a big assumption), and the inevitable result is that any civilization that survives and has the requisite minerals available, will eventually transition to some form of solar and nuclear power.

    • achingshoulders

      You are not alone in your thought. That's why the development of alternative energy sources such as photovoltaic solar and hydrogen fusion are funded. It is a race though; the "booster rocket" push given to human civilization by fossil fuels will end some day. If we are not in "technological orbit" by then (functional fusion power, cost effective solar power, manageable fission power [i.e. with radioactive waste recycling instead of storage] or SOMETHING0 then I can see a "crash and burn" like you reference.

      • G

        Excellent analogy to booster rockets and orbit. I'll start using it in place of the one I've used so far (digging ourselves into a hole and burning the ladder).

        Thorium fission is a good bet for the foreseeable future: it's safe, the reactors can be designed to be self-limiting in a loss of coolant accident, and it can't be used to make atomic bombs. This will give us more than enough time to develop viable fusion. And it will also enable us to give the fusion scientists the time they need to do it without having to make unrealistic promises that just fuel cynicism. So we can say thorium for the next few centuries, and fusion thereafter. Meanwhile making good use of renewables wherever possible, for the sake of preserving all of our concentrated fuel sources as long as possible.

    • gbarnold1

      Earth's fossil fuels are easy, but solar energy does not just fall on the Earth; it washes by the Earth, in all directions, in vast quantities. Once we begin to harvest this source of energy, we will think of the fossil fuel age as quaint, as we think of the age of whale oil and horsepower. If furthermore we finally tame fusion generation, almost any task can be accomplished. Even if we never exceed the speed of light, starships traveling at relativistic velocities can reach the far side of the Galaxy within a few hundred thousand years, a blip in the Galaxy's timeline. Peace.

      • G

        Even a small single-digit percentage of c is sufficient to enable a colony ship to make the trip to nearby star systems in a few thousand years. That will require new technology but not new fundamental science. We can do this if we want to.

        (And no doubt there are fiction stories somewhere, about a colony ship arriving at its destination only to be welcomed by an established human civilization that left Earth later and used far-advanced tech to get to the destination planet earlier. "We're sending you the genetic information to enable you to create some vaccines you'll need to take before you land here. You should be able to verify the safety of the vaccines for yourself. In the meantime, here's our encyclopedia so you can catch up on our history. Welcome home!")

    • Tamara

      We developed the use of oil to the present level, no doubt we will be equally able to use other forms of energy in 1000 years. I have faith in humanity.

    • G

      And that is the doorway into Omnicide, the total holocaust that extinguishes the entire lineage of Earth life when an asteroid eventually slams into Earth, or in 1/2 billion years when increase in solar luminosity disrupts the carbon cycle and boils the oceans.

      This is why sustainability is essential: to preserve the resources, knowledge, and capabilities, that will enable our distant descendants to continue the lineage of Earth-originated life and knowledge by spreading to other planets and other star systems: preventing the ultimate holocaust and instead achieving persistence of the lineage of Earth until the last star blinks out.

      In this context, the failure to deal with climate change takes on a much greater moral significance: the risk that climate catastrophe could knock us off our precarious technological perch, never to climb back up again. We already have the technology to solve the climate crisis: renewables and fission, including thorium fission in the near future, and fusion in a century or so (thorium fission will buy more than enough time, so we can give fusion scientists the time they need to do the job without making unrealistic short-term forecasts that so far have only given rise to cynical public reaction). All we need is to exercise the will.

  • http://atlantarofters.blogspot.com The Sanity Inspector

    "If the universe be inhabited, what a scope for folly; if it be not inhabited, what a waste of space." ~ Thomas Carlyle

  • Cloudface

    “I am sorry to say that there is too much point to the wisecrack that life is extinct on other planets because their scientists were more advanced than ours.”

    —Sen. John F. Kennedy, December 11, 1959.

  • Frank

    If you think of rationality and consciousness as a process of the universe waking up and becoming aware of itself, you look at archeology differently. what if the earth is the only place in the universe where consciousness currently exists - as the Bible suggests? what if - asteroid, war, germs...we become extinct? this grand show, this exquisite universe - to exist, without any awareness?

  • montana83

    Dead civilizations? We have them right here. The Romans, The Greeks, The Communists, The Nazis and soon the Socialists/Progressives. What do they have in common? They all went bankrupt morally and financially and became pushovers by those that weren't as stupid.

    • Oddvar Johan Martinsen

      Yeah - sure - whatever - the conservatives is the ones who have been bankrupt morally for a long time - they just have a lot of money to spend - and wil loose that too in the end... The future do not end when conservatives got the upper hand -it never does - the future belong to the progressive world - not the past, as Conservatives tend to love...

  • markbuehner

    The problem with most of these theories is that we haven't considered the Why of what alien civilizations might do. We look at our own recent history and extrapolate it to levels of advancement that make no sense. Assuming an alien civilization is likely to construct a Dyson Sphere requires us to believe a civilization will require ever increasing amounts of energy... a valid assumption for an expanding civilization with technologies that requires ever increasing amounts of energy. But is that likely? When man has mastered his mortality, an expanding population and even reproduction become open questions. If you take a finite population pared with levels of tech that would likely allow a complete 'virtual' existence, the level of energy consumption for such a society might be less than our own. Sure, there is space travel, exploration, perhaps colonization, but if the universe is as empty and far apart as it would appear, whats the point?

    We may not have spotted any advanced civilization because they have no use for being spotted. Perhaps theyve all met and been numbed to boredom by infant civilizations like ours. For that matter it may be sheer boredom that kills off advanced civilizations. We just have little insight into the nature of immortality.

    • lurs700

      Actually no. If a civilisation optimises the consumption of energy, it will mean that it will be able to do and compute more things with a given amount of energy. But it doesn't mean that they will try to do and compute a constant number of things, it will mean that they will increase the number of things to do with the available energy

      • markbuehner

        Assuming an ever increasing number of 'things to do'.

        • lurs700

          as human population has grown, a backward trend reveals that productivity per capita, well-being and 'things to do' have grown as a power exponent between 1.6 and 2.0 on the size of the information-connected population. There is no reason to believe that trend will change. There are many reasons to think that it will scale up as we expand on the solar system

          • markbuehner

            in 10,000 years of civilization... which is a pittance compared to the time scales we are discussing. As I said, a cro-magnon could look at the last 10,000 years of his species and project out our current population- the world must be covered with a sea of raging bonfires and the skies choking with smoke. I could certainly be wrong- but I posit there just isn't that much worth doing past a certain threshold of technology and essentially infinite energy.

          • thefermiparadox

            I'm not so sure. Radio, Computers and the internet were game changers. I agree with Arthur C. Clarke in that we might be able to imagine scientific and technological progress a hundred or even 500 years out but no way could someone 200 years ago imagine our modern society. Social and political institutions are the difficult things to imagine. I could be wrong but I think it's a false equivalency to assume each time is equally ignorant.

          • markbuehner

            Maybe, but 200 years is a rounding error in the scale of time we're contemplating. We're trying to imagine societies thousands of years advanced (at least), and as you say, advanced in ways that i think are increasingly unpredictable (if not unimaginable) due to the revolutionary escape from evolutionary and biological constraints and influences. I don't think we've given much thought to how the mind deals with the prospect of essential immortality, or the digital existence. To date our minds have been fairly well equipped imagining a future with ever improving biological breakthroughs. This is something quite beyond that.

          • thefermiparadox

            Well said. You're probably right. This is a difficult topic. We do still have our animal emotions and I agree we have not given much thought to how the mind deals with the prospect of essential immortality or digital existence. I know this sounds ridiculous but I try to think of what else could come in the future that is unimaginable like how the Internet could not be conceived of in the past. I'm sure I sound as ignorant as people in the past but it feels intuitively like we can project aspects of the future since we are at the beginning stages of the computer age. Will be interesting. Wish we were around to see it :)

    • dizzie1


    • G

      You're right on target about energy, but "not even wrong" about immortality.

      The fatal flaw of the Kardashev scale is the assumed correlation between advancement and energy consumption, which works for 19th century technology but fails at the speed of Moore's Law. In its place I would propose a scale where level 1 is a technologically capable civilization on a single planet for an extended period of time, perhaps a thousand generations; level 2 is a civilization that is interactive across two or more planets in a single star system, and level 3 is a civilization that is interactive across two or more star systems. Level 4 would be level 3 across a sufficient span of space as to be immune to a gamma ray burst at any point in the network, which at present means a radius of about 2,000 light years.

      As for immortality: One of two things is true. Either a mind can continue to exist in some form after the death of the biological brain, or it can't. But please let's not indulge in the popular pseudoscience of "upload" and reincarnation into computers. If you can reincarnate into a computer, you can reincarnate into a cat.

      Immortality through assimilation into a latter-day Borg is nonsense. Immortality through magical biotech is also nonsense. In any case, a body that won't die of natural causes will eventually die a most unpleasant death through some form of violence or injury, and the relative infrequency of such deaths would make them all the more unbearable to the living who are left behind.

      As for "gradualist" replacement of neurons by silicon prostheses, that's also pseudoscience, along the lines of believing that prosthetic limbs will make you Superman. They won't, and it won't.

      Either there's an afterlife, or there's nothingness. If there's an afterlife, there's a new universe to explore there. And if there's nothingness, then there's nothing to fear.

      • markbuehner

        There is very little science here, just the assumption (untested mind you) that your 'mind' is more than a collection of neurons and how they are wired together. You could be right. You could be wrong. I don't know of any TECHNICAL reason a human brain cant be replicated artificially given a sufficiently advanced technology. But working backwards to assume its impossible because the human mind must be mortal and therefore the technology can never exist is a straight up act of faith.

  • JasonAW3

    There are options that few have even considered as yet.
    In theory, should a civilization become advanced enough to bend space or create 'pocket universes' such things as Dyson spheres would become obsolete, as while finately large, the 'pocket universe would loop back upon itself, trapping whatever energy that a star or set of stars produce within that pocket of folded space.
    On would imagine with enough advancement that folding space around a predetemined volume would likely be both more effective and cost much less in time, manpower and resources than would disassembling the entire mass of a solar system to harness the power of a star.
    Such pocket universes may even cause gravitic lensing, much the same as a blackhole would, but with the occasional brief flare of energy as craft exit through some form of gate that would allow them to travel elsewhere.
    Personally, I would not be eniterly suprised to find that a number of what we think are black holes are in actuality, pocket universes.

    • G

      Pocket universe != perpetual energy from finite stars. Putting a star inside a spatial loop does not keep it going after its hydrogen supply runs out. Putting a lightbulb inside a spherical reflector does not keep the light shining after you turn off the electricity to the bulb. Energy dissipates from sources to sinks. All thermodynamic systems eventually reach a stage of entropy or heat-death.

  • Oh_Long_Johnson

    Jodie Foster said the question she would ask an alien civilization, if given only one chance, would be "How did you do it?" How did they survive the bottleneck of nuclear war, climate change, and overpopulation (along with a host of other imminent threats to humanity)? If humans are a typical example of how civilizations deal with technology, the universe may be a sparse habitat. And the Drake Equation goes to 0.

    • Melissa

      Of course looking for ruins does not presuppose that they survived. That is the beauty (and melancholy) of being an archaeologist.

    • G

      We already know how to get through the bottleneck. All that's needed is the will. Either we achieve sustainability voluntarily and nicely, or nature's going to do it for us, involuntarily and not-so-nicely:

      = Convert our energy supply to renewables and fission while developing fusion.

      = Voluntarily reduce population to sustainable levels via education and family planning. This in turn requires global equality for women, which requires uplifting backward cultures that presently treat women as property (and yes, the word "backward" is as appropriate for that as it is for slavery; humans are not property and progress is not culturally neutral).

      = Reduce consumption of material resources generally. To achieve a tolerable standard of living for the world's poor without generating an unsustainable resource depletion will also entail reconfiguring the economy away from the present unsustainably inequitable distribution of resources.

      = Ultimately, overcome the atavistic urge of some humans to dominate other humans. This requires evolution of global culture. Hint: violent media are a sign of cultural illness that will have to be cured along the way.

      = Enact global economic and diplomatic incentives for progress along these paths, and disincentives for unwillingness to participate.

      To make this terribly clear, if we were facing the certain explosion of the Sun in 500 years and needed to achieve interstellar migration before that time, or if the Earth was attacked by hostile ETs, we would darn well get our act together, just as we did during WW2 to defeat Naziism and fascism generally. Imminent doom has a way of sharpening one's sense of priorities. The fact that we have a half billion years before increasing solar luminosity renders Earth uninhabitable, does not change the fundamental dynamics. Either we evolve, or we perish. Same as it ever was.

      And whether you get a message along these lines from a hypothetical deity, an ET radio signal, or a smart highschool kid from some obscure village in a country whose language you don't understand, doesn't change anything either. The facts are convergent, the way forward is clear.

  • Pavel Chichikov

    When Cook's expedition arrived at Botany Bay, the locals were observed not to pay any attention at all to his ships. Apparently, these were so strange to them as to be invisible.

    • G

      Darn, you gave away our secret! Now I'll have to put a tarp over my saucer in the back yard, so the neighbors don't figure it out. Poo.

    • basenjibrian

      Is this true...or apocryphal?
      The Aztecs and Mayans certainly didn't behave this way.
      And why would the natives not "pay attention" to something strange to them?

  • speculator42

    Perhaps recent observations of X-points or electron diffusion regions in our own solar system could lead to insights. This phenomenon also applies to our solar system as a whole - so perhaps the exchange of these energetic particles could be used for energy or communication by a more advanced civilization. If so, what signatures would we look for? Maybe we could even discover that signals are already being sent, but we just aren't listening on the right channels - we should be deciphering particles, not waves.

  • ThomasWamm

    I have occasionally wondered if some planetary nebulae are evidence of mass emigration by replicating machines setting out to colonize the galaxy.

  • Inigo_Ona

    I think a highly advanced may well have mastered dark energy/dark matter and be exploiting them as sources of energy obviating the need to use their sun and galaxy as energy sources. A highly advanced civilization may well have moved beyond using the electromagnetic spectrum for communication and our efforts with SETI and listening to the electromagnetic spectrum may well prove to be fruitless as no one but us is broadcasting in that range..

    They should add another type to the Kardashec Scale for Civilizations that have these capabilities.

    Of course whole civilizations that consist solely of dark matter may exist. As someone once said, the truth is out there.

    • G

      Bingo. They aren't using the EM spectrum in the manner we expect.

      If you're an interstellar telecoms engineer, why would you design a system that wastes energy radiating in useless directions, when you can design a microwave laser or something similar, to communicate far more efficiently between the planets and star systems that comprise your civilization?

      And that's why we've been missing them so far.

      What we need are major space telescope arrays that can resolve down to the level of imaging the planets we're interested in. All we need do is pick up light emissions from the dark side of a planet, with spectra that are not naturally occurring, and we'll have spotted an ET civ with artificial lighting. We can build the technology in our lifetime to get a good start on this. And chances are that it will discover a civilization rather quickly, as our present technology has been discovering planets quickly once we knew what to look for.

  • Drago

    When every cubic centimeter is pregnant with virtually limitless free energy, there is no need to create elaborate engineering projects.
    A Dyson sphere is impossible to protect from falling objects like comets and planetoids.

  • hp b

    There's no such thing as Dwarka
    There's no such thing as Dwarka
    There's no such thing as Dwarka..

  • Bluetides

    Exopolitic Hubris

    The UFO phenomenon poses many unanswered questions and contemporaries have gone to great lengths to attempt to answer these questions. To make the subject even more challenging, there is disinformation and a ton of noise. When we glean through the noise, we find, to a large extent, most of the mystery has been solved and many of the baffling questions answered.

    The remaining question that has not been answered is “If they are real, then why do they not just simply land on the Whitehouse lawn, hold a press release announcing their existence, arrival and intentions?”

    Good question.

    In present reality, the answer to this question is not a very popular one and it’s not something as a species we are in any way prepared to look at. The bottom line is that there is really nothing here on earth, as expressed in our humanity, which is of any interest to someone who has mastered interstellar travel and transcended their pre-stellar limits that we in humanity have yet to address. It is only our hubris to think that what we have evolved to offer the cosmos is of any consequence.

    Get over it, come to grips with the fact that to the trans-dimensional entity, at humanity’s present bandwidths, “we have the porch light on, but clearly, nobody is home”.

    Let’s just say we were able to briefly catch one of these travelers attention and he or she indulged us in an exchange dialogue. What would he learn from the earthling? Idle chatter about the weather? No, not chemtrails, we can’t go there, the
    latest on Dancing with the Stars or who was booted off the reality TV Island? Perhaps a discussion on the wisdom of bombing a modern country of 75 million intelligent innocent people? Even offering up some esoteric science or so called wisdom would not do the trick. I’m afraid it would be a pretty short conversation as nothing of interest could be offered to our Star Traveler.

    We on earth need to appreciate that the Star Traveler has a functioning relationship with reality and that we simply have not evolved or possess such a faculty. They have a functioning relationship with reality that permits them to understand the
    material, dimensional and the energy informational encoded holographic realms
    we all inhabit. The entity uses his or her brain and even a small portion of
    the mind, where we on earth use virtually neither. A species with a modicum of a functional relationship with reality would have a school of consciousness, would it not? There is no such thing on this planet and until there is, we will remain locked
    in our prison of hubris.

    On the other hand, cave art and native lore tells us the Star Travelers have visited many of the tribes millennium ago. We have their accounts in vivid detail in most of the world’s native lore and cave paintings. What did the tribes have to offer of sufficient interest to the Star Travelers, warranting species interaction where nothing we have today is of any interest to them?

    Stellar minds and trailblazers like the dear departed Terrance McKenna provided clues in sharing detailed trans-dimensional experiences with us to no avail. Terrance had personal interaction with these entities with the use of sacred herbs. What was
    lost on Terrance was the fact that we have these magic DNA activating hormones
    in our own brain chemistry kit and the fact that we can use our home grown
    glandular secretions to expand our consciousness bandwidth, availing ourselves
    to fuller functioning relationships with reality, accessing the domains of the
    more grown up entities in our shared space.

    When people hear this they usually go to a place in their mind moaning about having to learn the impossible when in fact is like a duck taking to water to learn how to properly use the body and fuller capacities of our brain. It was designed and meant to be and the technique is actually quite easy to learn. To learn how to activate these glands and achieve pituitary and pineal gland secretions, go to the 2011 archives at: http://fukushima50.blogspot.ca/

    The message is loud and clear from John Mack’s extensive abductees work. What is of interest to the Star Travelers is our Royal Flush DNA hand that we’ve been dealt. The fact that we as a species have yet to realize the great potential to what this special DNA resource means to the universe is another matter and does not diminish its value. We’ve set our transcendental bar too low, a Ph’D and a bank account is not any measure of a successful life (that was never our purpose). Each of us has to become a human being (not to be confused with a human doing) morph a mind of Terrance McKenna and a Dr. Bill Deagle and you would have a starting place to play the game called life. Kick it up.

    As well the universe seems to have a built in protective viral defensive mechanism to contain aberrant mutations so as to not infect broader space. It’s clear from the hidden archaeological record that a species like ours comes and goes when we fail to transcend our self imposed limits/fears and learn to embrace empathy, love, transcendence, creativity and infinity.

    We now near another critical threshold where we self destruct or somehow find a way to join our Star Traveler in the discovery/destiny of our shared future or not.

    What’s your pleasure?


    • G

      IMHO Terrance McKenna was engaged in "psychedelic fundamentalism," interpreting his visions as literally true rather than as symbolic. I would strongly advise against repeating his methodology, for whilst DMT and psilocybin are "safe when used as directed" in properly approved medically supervised settings, much risk, up to and including the risk of psychosis, is entailed in using them without those safeguards.

      There are few alive today who have the wisdom of an Albert Hofmann or an Aldous Huxley as to the proper use of these compounds in unsupervised settings, and it is highly doubtful that any of the readers of this column are so enlightened.

      In the end, meditation will get you there with practically zero risk and with appropriate wisdom developed along the path.

      Enlightenment, like the fog in the poem, creeps in on little cat feet.

      • Bluetides

        The Vedics left us with the Caduceus map and that is all about secreting the golden brain chemicals pituitary and pineal (DMT). The star brothers use their brains as they were intended and we do not. Advanced civilization have come and gone and we are doomed unless we kick it up and get in the interstellar game. The prerequisite is to rejuvenate our atrophied pituitary and pineal glands and kick the bandwidth up.

      • Bluetides

        I appreciate the comments on safety.... fortunately nature took care of that in designing our brains so that the pineal (DMT) glandular secretions are regulated from the pituitary gland. Terrence and the rest of these jungle cowboys missed that point.

  • jtremain

    Scientists have total disregard for all discoveries that they can not explain within their predefined context.

    There are thousands of documented discoveries from the 1800, 1900'a of burial grounds in the USA and world containing giants, human like but not human as we know human; totally ignored and disregarded by our current day "finest" archeologists.

    Scientists can't explain how the pyramids were built so they tell you 70 ton stones quarried 500 miles were hand pulled with ropes thru the desert. Tell me more oh wondrous scientists.

    ET to them is just a movie. Their egos won't allow the the existence of alien life or ET craft.

    If you are waiting for scientists to explain the real truths of this planets history and universe, you will be waiting way past your death time.

    • thefermiparadox

      If we go with your route there will be no new discoveries or progress. Look at the UFO phenomena. Nothing new has come of it since the 50's. True sign of pseudoscience; just like homeopath, astrology and other woo.

      • Wildblood

        Indeed. Before the "Age of the UFO" we spotted elves in dusky lanes, pixies in hedgerows and fairies in the back garden. All that has changed is our back garden has become rather larger. And now that we have turned the arc lamps on, well, as you say "nothing new has come of it since"...

        • G

          "Powerful beings who come from the sky" is a universal human archetype. In times past they were angels with wings; today they are ETs with spaceships. But it's interesting that we don't have a comparably detailed and extensive mythos about beings from the sea, with a few notable exceptions.

          This I would attribute to the particular quality of awe of gazing into the night sky, something quite unlike the different sort of awe one feels at contemplating the ocean. One can easily go into the ocean at the beach, and one can sail along the coast; whereas flight into the sky was unattainable until relatively recently in our history. Thus the sky and the stars remained the deeper mystery, and the larger source of archetypal entities for a longer span of human history.

      • G

        Actually, something did just come of "UFOs" this year. The US Air Force declassified a bunch of its R&D material on the U2 aircraft, that flew from (you guessed it!) Area 51. The U2 flew three times higher and three times faster than anything in its day, and no doubt was the source of many UFO reports by credible persons such as military and civilian pilots.

        So I think we can say that this information probably solves at least half of the decent UFO reports from that era, leaving a small number that are still legitimate unknowns. The solution to the latter is to fund a project at NASA to observe and study whatever aerial puzzles they can find, and that should take care of that, ET or not, without any further woo or nonsense.

  • Felipe Osorio

    Great article. I think if we consider certain simple scientific axioms, such as nature repeats itself, we should assume that there are other characters in the cosmos since we are a product of nature. The more pertinent question is whether the civilization can preserve itself from self-annhilation when encountering sufficiently higher technologies.

  • Don

    This country is to busy paying for programs to buy votes, especially Liberals and their feral low information voters.

    • http://raymondduke.com/ Raymond Duke

      So hateful.

      • G

        Yes, and he fails utterly to recognise the moral bankruptcy of his own hatreds. He also fails to recognise that science & space are non-partisan endeavours. President Kennedy, a liberal Democrat, initiated the race to the Moon. President Nixon, a conservative Republican, spoke to the Apollo astronauts upon landing. President Bush, a conservative Republican, promoted the idea of a human mission to Mars. President Obama, a liberal Democrat, has supported the idea as well.

        Some day when humans land on Mars, they will speak to the leaders of all of the nations they represent: republics, constitutional monarchies, parliamentary democracies, and possibly a nominally communist state if China remains so by that time. And it will be a moment of supreme unity of achievement for humanity, that transcends parties and politics.

  • Doug Doakes

    I'm all for pure science, but this looks like a black hole. We have not yet picked up a peep in our decades-old sky-blanketing electromagnetic spectrum scan.

  • Melissa

    Thanks for a really splendid read. As an earthly, dirt-digging archaeologist, I found this fascinating and wonderful to ponder!

  • Ramon Antonio

    Interesting! But there's a catch! The notion of time you mention is incorrect in terms of human lifetimes. The light from Alpha Centauri may take 4 years but that is at light velocity, that is 366xxx kms. per second. In terms of human lifetimes those 4 years take generations. I have been looking for a simple way to calclulate the equivalence but is not easy.

    You sould make an Addendum to this article explaining that equivalence. For one reason: whenthat light started its trip to earth here we were probably in the pleistocene or something about even though we are just 4 years away. For if we try to get there, at the best qchievable speed we would take thousands of years to get there.

    The reality of interstellar time is not a linear progression but a multivariable experience. Thanks for taking us nto this fascinating journey.

    • gbarnold1

      I think you are confused. Whether or not we travel, the light from distant stars takes a set amount of time to get here. Sun: eight minutes. Alpha Cent: 4 1/2 years. Furthermore, we don't need to break the "light barrier" to reach the stars. Fusion power or anti-matter power will get us up to a high percentage of the speed of light, and at relativistic speeds, one crew can sail across the Galaxy in their lifetime, or a couple of hundred thousand years in our lifetime. Just a blip in the cosmic view of things.

      • Ramon Antonio

        Thanks for the response. But nope, I'm not confused. The stuff I'm talking about is the most recent discussion in cosmology.

        Within the boundaries of our own solar system the sun's light takes 4 minutes. But with the most advenced proposal in desks right now, Mars will be 30 days so the sun will be... How much? Make the calc.

        As we approach the speed of light, whatever travels is not a phisical construct but its atoms. Nothing known can withstand such velocities. The stresses are imposible for any structure to manage. So we are talking about theorethical space speeds, not human scale space speeds.

        That's what I suggest you expand. Whatever travels at the speeds you suggest, is the human mind. Human life and our requisites to remains alive, as of today cannot.

        • Josh

          This is grade-A, pseudo-scientific, jabbering nonsense. Sorry.

          • Ramon Antonio

            Maybe. But Star Trek is totally that. And most of the movies we see that are based in humans traveling to the stars in their lifetimes.
            Even if suspended animation is achieved, it depends on machines that maintain a human for all those years without maintenence. Are we even near such a machine?
            My only intention in this comment is to call for a really deep and serious evaluation of the basis required to achieve star travel and the objective posibilities of mankind right now.

          • Ramon Antonio

            For the record. Here is more so called pseudo science to consider:
            Read as it is by a top cosmologist... Can anyone be sure of anything we think? That's what I'm saying.

            Cosmology as of now is evolving. Everything is being not only discussed but measured. The issues of this article are based on scientific research costing billions and they signal that we have to recheck everything for nothing is what we have thought to be.
            This is no pseudo science. This is science, actual science, not mysticism or New Age or Scientology beliefs. So please, don't resort or expect easy and understandable comic book explanations. There are not. Immense complexity is the only possible scenario and an evolving one. We even have no complete theories for what we are observing for the observations per se are by definition incomplete in our lifetimes. And we have to listen, ponder and respect all possibilities.

            So who cares if the light of the most near constellation reaches us in approx. 4 years? That is not the issue. The issue is where does that constellation really is? In our universe or is it part of another one intersecting ours. open minds and consider all possibilities. And if you need, take one or two martinis to aid your expanse of mind.

  • mikeysnoni

    The greatest discovery of all will most likely be that we are truly alone...what a chilling, unsettling thought for most people to contemplate. Of course, no one can ever say with certainty that there are no other civilizations, because no matter how much of the universe we explore, we can never explore all of it.

    • Rockin_Roben

      Life had to start somewhere, and since we live near an ordinary star and are made of ordinary materials it doesn't seem likely that we're the first. Possible, but probably exceedingly unlikely.

  • Tamara

    You are looking for alien civilizations in space... start in our planet...

    • andrewp111

      Haven't there been strange objects found inside sedimentary rock strata?

  • Anon

    Great article. Just wanted to mention that Schliemann reportedly said, "I have gazed upon the face of Agamemnon." during his excavations in Mycenae, not Troy (hisarlik).

  • Rockin_Roben

    Any civilization that could build a Dyson sphere likely could camouflage it as a defense against violent civilizations such as our own.

  • Ingolf Stern

    Or the concept of "defense" is anathema in the larger universe. It is likely that the larger universe, a realm of which we are wholly ignorant, is a cooperative system and not competitive like humans want to imagine it, or like what humans would create. Images of spacechips with laser cannons and death-star planet crushers are pure hype and propagande, fear mongering. You cannot get to a high "type" of civilization and engage in warlike conduct as well. Expanding local norms into universal modes is almost purposeful ignorance. There just isn't any way anyone else, anyone who can travel across space, would be stupid enough to engage in war and profit-seeking like many humans. The endeavors would seem to work at cross purposes, and be mutually self-cancelling.

  • gilcarlson

    Once you read all these messages from the aliens, you will never
    be the same again!

  • Shaun Maximusp

    Quote: "Beech thinks blue stragglers could mark a Kardashev Type II culture trying to preserve its habitat."

    I agree that blue stragglers look kinda incongruous and worth another look but wouldn't yellow or orange or even red stragglers (no idea if they exist or are expected/suspected to exist) equivalent to these blue oddballs be even more promising targets?