StarSearch: Our Hunt for a New Home World

by Paul Gilster on March 14, 2016

His interest fired by an interview with interstellar researcher Greg Matloff, Dale Tarnowieski became fascinated with the human future in deep space. One result is the piece that follows, an essay that feeds directly into a recent wish of mine. I had been struck by how many people coming to Centauri Dreams are doing so for the first time, and thinking that I would like to run the occasional overview article placing the things we discuss here in a broader context. Dale’s essay does precisely this, looking at our future as a species on time frames that extend to the death of our planet. Dale retired in January 2015 from the position of assistant director of communications with New York City College of Technology/CUNY, a veteran journalist and editor of “Connections,” the college’s print and online magazine. He also did considerable writing for the New York City College of Technology Foundation and its annual Best of New York Award Dinner (and continues to do so on a freelance basis). Here he reminds us of the Sun’s fate and asks how — if we and our planet get through our technological infancy — we will find ways to move into the Solar System and, eventually, out into the Orion Arm.

By Dale Tarnowieski

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Mother Earth – our home, sweet home – won’t be our home forever. In one billion years, give or take, increased heat from a steadily warming Sun will cause our planet’s temperatures to double, its oceans to boil away, and its land surfaces to turn to sand or melt. Assuming we’re still around, we’ll have to relocate before that happens.

A billion years is a long time off, so why the hurry to establish a foothold in space? One answer comes from astrophysicist Stephen Hawking, who warns that we may have as few as 200 years to establish permanent settlements on other worlds and begin mining our solar system for its bounty. Our numbers and the depletion of our planet’s finite resources are growing exponentially, as is our ability to alter the biosphere for good and ill. Within two centuries, Hawking contends, we could exhaust the resources available on Earth essential to our survival and damage our environment beyond repair.

But assuming we successfully respond to these more immediate challenges, the longer-term threat to our survival posed by a progressively warming Sun is one we won’t be able to avoid. We are already contemplating the use of mirrors in space to deflect sunlight as an anti-global warming measure as well as devices called space sunshades at neutral-gravity positions in the Earth-Sun system to reduce the increasing heat from our parent star. But such devices will do nothing to protect us when that heat becomes so intense that our only option will be to abandon our planet.

Now middle-aged, the Sun’s luminosity has increased 30 percent since its birth 4.6 billion years ago and will increase another 10 percent over the next one billion years. The radius of a more luminous Sun is projected to expand an estimated 200 times within four-to-five billion years and Mercury, Venus and possibly Earth and Mars will be vaporized.

Numerous natural or man-made catastrophes could bring most or all life on Earth to an end before the excessive heat from a warming Sun compels humankind’s relocation. But assuming no such catastrophe occurs, that move is only the first of two we’ll have to make. Several billion years later, it will be necessary to leave the solar system altogether as our dying Sun begins to swell.

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Image: A charred and glowing Earth of the far future, the Sun having long since entered its red giant phase. Credit: Wikimedia Commons CC BY-SA 3.0.

Holding Off the Inevitable

Could the abandonment of our world be avoided? In 2001, researchers Don Korycansky of the University of California-Santa Cruz, Gregory Laughlin of NASA and Fred Adams of the University of Michigan suggested that by maneuvering an asteroid 100 kilometers wide approximately 16,000 kilometers above Earth’s surface once every 6,000 years, we could slowly nudge our planet away from a more luminous Sun. But a collision with an object of such size would only have to happen once to prove catastrophic.

When our time on Earth runs out, the fortunate among us will join those already dwelling aboard orbital settlements circling more distant planets or their moons. Current thinking envisions others relocating to huge mobile in-space habitats called world ships or to open-air or enclosed settlements on Mars – the open-air variety depending on our successfully terraforming, or environmentally modifying, the biosphere of what at present is a frozen desert of a planet.

None of the other planets in our solar system is now remotely habitable. Closer to the Sun, a nearly atmosphere-free Mercury’s temperatures vary between -173 Celsius at night to +427 Celsius during the day. The latter is hot enough to melt lead. Venus is even hotter and possesses one of the deadliest atmospheres in the solar system. Farther from the Sun than Earth, Mars’s thin atmosphere is composed mostly of carbon dioxide and the planet’s weak gravity poses problems with respect to the retention of atmospheric gases. The four even more distant giants – Jupiter, Saturn, Uranus and Neptune – all have relatively small, dense cores surrounded by massive layers of gas. Jupiter and Saturn have thick atmospheres consisting primarily of hydrogen and helium, while Uranus is a world of liquid ice and Neptune home to wind speeds ten times those of the strongest hurricanes on Earth.

There are proposals for colonizing all of these worlds, including one that calls for the construction of an artificial surface together with its own life-supporting biosphere above the existing atmosphere of Jupiter. But among these proposals, the terraforming of Mars seems the most feasible based on current and anticipated technology.

Formation and Destiny of the Solar System

All stars are born and die, and our Sun is an ordinary yellow dwarf star born in a molecular cloud of dust and gas called a nebula. Consisting largely of hydrogen, the denser parts of that nebula underwent gravitational collapse and compressed to form a globule, or spinning ball of extremely hot gas, that later began to cool as a result of its emission of radiation.

As collapse progressed and the globule’s hydrogen atoms drew closer together, the temperature and pressure within that massive ball increased tremendously as did its rate of rotation. This increase in rotational speed also increased the resulting centrifugal force, causing the ball to form a pancake-shaped disk of stellar debris that extended far into space. This debris eventually coalesced through accretion into the four inner rocky and four outer gas or ice planets and other objects to which our solar system is home.

The four inner planets – Mercury, Venus, Earth and Mars – are called terrestrial worlds, which are smaller solid bodies made up of rock and metals with atmospheres of varying densities that were greatly modified early on by sunlight and the solar wind. The reason the four outer gas or ice giants are so much larger is that their greater distances from the Sun preserved, in part, their thick primeval atmospheres that condensed from the solar nebula.

When during the Sun’s formation the temperature of its core reached 15 million degrees Celsius, a process called nuclear fusion began, one sparked by the collision and binding of the core’s hydrogen atoms and their conversion by means of the intense heat produced into helium atoms, the second simplest and lightest of all the elements. This conversion created powerful outward forces of radiation pressure that eventually counteracted the force of inward gravitational collapse.

But as the Sun ages, the time will come when nuclear fusion will temporarily cease as our parent star begins to exhaust its supply of hydrogen and its helium content builds. This temporary cessation of nuclear fusion will briefly eliminate the resulting outward pressure and the Sun’s outer layers will fall inward on its core. This collapse will greatly increase the pressure on the core as well as its temperature, re-igniting the fusion of the Sun’s remaining hydrogen and triggering the fusion of its sizable accumulation of helium. The burning of helium will produce large amounts of carbon, which will act as a catalyst to increase 1,000-fold the rate of the fusion of the Sun’s remaining supply of hydrogen.

The greatly increased temperatures produced by this more intense fusion process will generate even more forceful outward pressure and the Sun will begin to swell enormously by pushing its outer layers deep into space. The movement of these layers away from the core will result in their gradual cooling. Less hot, they will appear less yellow and take on a reddish color as the Sun transforms into a red giant. Our parent star will grow increasingly unstable and release huge and violent bursts of solar material and heat. Because of its corresponding reduction in mass, the Sun’s gravitational sway will weaken and the orbits of the outer planets and other bodies spared incineration will change.

After eventually exhausting its nuclear fuel, the Sun will transform into a white dwarf star about the size of Earth. And theory has it that a very long time after that the Sun will become a cold and invisible dead star called a black dwarf. But the time required for a white dwarf to reach this stage is calculated to be longer than the current age of the universe and no black dwarf is believed to yet exist.

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Image: This image tracks the life of a Sun-like star, from its birth on the left side of the frame to its evolution into a red giant star on the right. On the left the star is seen as a protostar, embedded within a dusty disc of material as it forms. It later becomes a star like our Sun. After spending the majority of its life in this stage, the star’s core begins to gradually heat up, the star expands and becomes redder until it transforms into a red giant. Following this stage, the star will push its outer layers into the surrounding space to form an object known as a planetary nebula, while the core of the star itself will cool into a small, dense remnant called a white dwarf star. The protostar stage, on the far left of this image, can be some 2000 times larger than our Sun. The red giant stage, on the far right of this image, can be some 100 times larger than the Sun. Credit: European Space Agency.

Humanity in the Far Future

Life has existed on Earth for 3.8 billion years, with the earliest examples of the human species thought by most anthropologists to have evolved in Africa about 300,000 years ago and anatomically modern examples 200,000 years later. The earliest fossil evidence of the precursors of the human species dates to between 1.9 and 2.4 million years ago.

Assuming our survival over the next one billion years, natural evolutionary processes will allow us to adapt for a while to changing environmental conditions as the Sun becomes more luminous. For example, skin color in humans might become uniformly dark. But we will experience increasing sensitivity to pressure changes as conditions worsen and horrific storms of enormous magnitude become routine and the time will come when we are unable to adapt further.

As conditions on Earth deteriorate, we may continue to dwell above ground in highly protective structures located away from our planet’s equatorial and temperate regions. Such enclaves will have their own energy-generating facilities and water and oxygen will have to be recycled.

But eventually, nearly all humans still living on Earth are likely to take refuge underground. In time, sub-surface or off-planet production of natural or synthetic foods will provide for all of humankind’s nutritional needs. And long before then, we will have moved to the full recycling of virtually all materials employed in the production of goods. Ground and air travel will be severely limited until such means of transportation become extremely problematic, and space elevators, rather than rocket-propelled vehicles, will transport people and materials to and from Earth orbit.

Toward Other Stars

The future exploration and settlement of nearby space beyond the Earth-Moon system will require many technological advances and innovations, including the use of solar system resources for propulsion systems that do not employ chemical propellants. For manned flights beyond the Moon, a generic in-space habitat module will need to be perfected. Shielding will need to be developed to reduce crew exposure to galactic cosmic rays and solar flares and solar flare warning time will need to be increased. Some type of landing vehicle, surface habitat and an enhanced space food system will have to be developed for missions to Mars and beyond.

Also required will be the development of technologies that enable us to explore the near-interstellar environment. First, advanced robotic probes will visit the heliopause at about 200 Astronomical Units or AUs, where one AU is the mean distance between Earth and the Sun. Later missions will explore the Sun’s inner gravitational focus at 550 AUs and finally the inner reaches of the Sun’s Oort Cloud at 1,000 AUs.

Much later, faster and even more advanced robotic probes will fly through neighboring star systems with potentially habitable planets. These will be followed by probes that will decelerate in selected planetary systems and dispatch landing craft to the surfaces of suitable planets in the habitable zones of targeted stars. Full computer management of these missions will be necessary, because even speed-of-light communications over such vast stretches of space will preclude real-time oversight by humans located in our solar system.

While nearly all of today’s rockets are fueled by chemical propellants, future spacecraft operating within our solar system are likely to be propelled by either the Sun or nuclear fission or fusion, which would greatly reduce travel times to Mars and beyond. Current thinking calls for spacecraft venturing beyond our solar system to be propelled by some type of fusion reaction or a light sail, although an antimatter propulsion system and electric sailing on the solar wind are other possibilities. Moreover, new systems of deceleration at journey’s end will need to be developed.

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Image: About as futuristic as it gets, this is a design visualization of a black hole augmented interstellar ramjet concept developed by Kelvin Long for the Initiative for Interstellar Studies. Credit: Adrian Mann.

The two principal dangers to humans in the manned exploration of space are cosmic rays and microgravity. Too large a flux of cosmic rays can result in cancer or mental degradation. Long-term exposure to microgravity can cause muscle and bone deterioration.

If a craft is moving rapidly, the induced cosmic ray flux caused by impacting interstellar ions and atoms could be alleviated by thick shields in front of the habitat section. A combination of thick shields and magnetic fields around the habitat would greatly reduce the flux of galactic cosmic rays. Microgravity effects could be reduced by spinning a ship in order to produce fractional Earth gravity on the inner rim.

If a craft is moving at a higher fraction of the speed of light, one problem is occasional impacts by cosmic dust particles. A shield in front of the craft or a combination of particle-detecting radar and particle-zapping lasers could alleviate this problem. If the ship must make a close solar pass, special care must be taken to protect crew and equipment from high-energy solar photons and solar winds.

Even close to home, spacecraft might be impacted by cosmic rays produced by a distant exploding star, or supernova. To protect the crew, a shield could be attached to the habitat to block the cosmic ray flux from the supernova. Since gamma rays are neutrally charged high-energy electromagnetic photons, mass shielding rather than magnetic fields would be necessary.

The dangers inherent in cosmic rays might be alleviated on manned trips to Mars through a method of travel described in a March-April 2011 Acta Astronautica article, “NEOs as stepping stones to Mars and main-belt asteroids,” by Gregory Matloff and Monika Wilga. This method makes use of space resources located not far from Earth – those small asteroids or comets known as “Near-Earth Objects” or NEOs. The article calls this form of travel “NEO hitchhiking.”

Most of those celestial icebergs we call comets reside in two locations far from the Sun in the distant Kuiper Belt and Oort Cloud, while most of the rocky and stony minor planets or asteroids are located in the Asteroid Belt between Mars and Jupiter. In recent decades, however, increasing numbers of extinct comet and asteroid-like objects have been observed in orbits that bring them close to Earth.

Following Earth escape, a velocity change would be applied to a human-piloted spacecraft bound for Mars, a change that allowed the craft to rendezvous with a NEO two to three months later. During the balance of the interplanetary flight and after the crew imbedded the craft within the NEO, the latter’s material would be used to shield the craft from cosmic rays.

While during any ship’s return voyage a similar strategy would be followed, various mission proposals suggest that diverse contingents of space travelers sent to Mars, for example, should expect to stay and never to return to Earth. Such one-way missions could be accomplished with less difficulty and at less cost. Their crews would establish settlements that would expand as additional travelers followed and those already there reproduced.

Terraforming a Close Neighbor

The terraforming and colonization of Mars – the only other planet in our solar system where environmental modification now seems feasible – are not absolutely essential to humankind’s survival. But the successful terraforming of that world could make possible a reasonable facsimile of an Earth-like existence for a sizable population. While much of the work of terraforming Mars would be done by robots, humans overseeing this effort would be largely confined to underground habitats perhaps built into extinct lava tubes to protect them from galactic cosmic rays. However, technological advances in high-temperature superconductors might enable the construction of giant artificial magnetic shields to insulate all early settlements and allow their Earth-normal inhabitants to reside above ground and shed protective gear as long as they remained within the shielded environments.

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Image: An artist’s impression of a terraformed Mars centered over Valles Marineris. The Tharsis region can be seen of the left side of the globe. Credit: Daein Ballard/Wikimedia Commons CC BY-SA 3.0.

Terraforming Mars would take a very long time and unfold in stages. The most distant from the Sun of the four terrestrial planets, Mars’s thin atmosphere is composed mostly of carbon dioxide. Its polar ice caps consist of a top layer of frozen carbon dioxide and a lower layer of water ice, and scattered elsewhere across areas of the planet are subsurface pockets of permafrost.

Evidence suggests that Mars once was home to at least one sizable ocean and that rivers of liquid water streamed across the planet’s surface and may exist underground today. More recent findings indicate that small streams of liquid water appear to flow on the surface during the planet’s warmer months. But steps could be taken to alter the trajectories of icy celestial objects to impact Mars at low velocities and deliver much of the water needed to create the vast reservoirs that would be critical to environmentally modifying that world. However, maintaining such liquid water reserves would first necessitate increasing the planet’s temperature and thickening its atmosphere.

In-space mirrors could be used to reflect additional sunlight on the planet and impacts by other celestial object could be engineered to help create a greenhouse effect that would warm the planet’s atmosphere and deliver the ammonia that would enable its nitrogen enrichment. Mars’s high carbon dioxide levels also could be utilized to help thicken its atmosphere.

Next, techniques could be employed to electrolyze some of the liquid water in the eventually created Martian seas. This would help produce the level of atmospheric oxygen required to sustain human as well as other Earth-indigenous animal life. What’s more, the process of passing an electrical current through water could be used to separate its hydrogen and oxygen components. Transformed into their separate gaseous states and then recombined in a combustion chamber, these components could serve to create energy for all types of uses.

After creating conditions to better retain atmospheric and surface heat, sections of Martian soil could be chemically and biologically treated and Earth-indigenous flora introduced to help produce even more atmospheric oxygen. However, it would be necessary to continuously work at enriching the oxygen content of the Martian atmosphere because of the planet’s weaker gravity, which poses special problems with respect to the escape time of gases.

In addition, Mars’s orbit around the Sun is more elliptical than Earth’s. It lacks a large satellite like Earth’s Moon and it is closer to giant Jupiter. These factors contribute to a periodic shift in the tilt of Mars’s axis, resulting in a destabilization of the Martian atmospheric composition, temperature and other environmental factors. Periodic corrective adjustments would be required.

Mars has half the radius of Earth and only one-tenth the mass, making the surface gravity on that world less than 40 percent of that on Earth. It has yet to be determined whether this level of gravity is sufficient to prevent the various health problems associated with weightlessness and how we would deal with these problems.

Surviving on an environmentally modified Mars could require genetic modifications to our species and other Earth-indigenous animal life forms. Genetically reengineered back on Earth, lower animal life forms would be introduced first and genetically modified humans later on. Modified humans and other animals might have larger eyes able to better function in an environment marked by reduced light from a more distant Sun. In addition, genetic alterations would be required for animal life to withstand higher levels of cosmic radiation in view of the fact that Mars lacks a substantial magnetic field to deflect incoming rays.

While many of our distant descendants will probably call Mars home, either below or possibly on the surface or aboard huge orbiting settlements, what will existence be like for others residing on the mobile world ships mentioned earlier? Such in-space habitats are likely to be of cylindrical or spherical shape, measure from less than one to as many as 10 kilometers in length or diameter and rotate around an axis so that their passengers on the inner rim can experience an analog of Earth-normal gravitation. If not as luxurious as those depicted in Hollywood’s fictional starships, the interior environments of these habitats will be comfortable enough. But tighter living quarters on the world ships could result in increased stress-related interpersonal issues among crew and passengers. Such ships will likely be totally recycling or resupplied using in-space resources, with only luxury items imported from Earth. Work is already underway to develop seeds that can grow into edible vegetables in only a few days and applications of 3D printing and more advanced technologies may one day enable the production of animal and other types of food products.

Destinations in the Galaxy

With the search for a new home world in interstellar space already underway, what kind of planet are we looking for and where do we expect to find it? Within our Milky Way Galaxy, there is a relatively narrow region called the galactic zone of life where life as we know could survive. Earth-like life could not survive in star systems located too close to the extremely dense and highly radioactive center of the galaxy, to dense star-forming regions with their high levels of radiation located elsewhere, or in regions in which certain higher elements are absent or in short supply. Moreover, the habitable zones surrounding individual stars in which Earth-like life could survive are also relatively narrow, and various factors would have to come into play in relation to suitable planetary bodies located within such zones to make them suitable for migration.

In interstellar space, we’re searching for planets of roughly Earth surface gravity located in the habitable zones of stable main sequence stars. Ideally, those planets will have day-night cycles similar to Earth’s and enough atmospheric oxygen to enable us to breathe, but not so much that combustion is uncontrolled. The average temperature on at least parts of the surfaces of those planets will have to be between the freezing and boiling points of water, which will have to be present on those worlds for humans and other terrestrial life forms to survive. Any life forms indigenous to those worlds should be more or less compatible with terrestrial life and not overly hostile. If indigenous DNA and proteins are similar to the varieties found on Earth today, virulent germs should be no more prevalent than here.

A cosmic event that could impact our interstellar migration involves the anticipated merger in four billion years or so of the Milky Way and Andromeda Galaxies. The two are part of a larger family of galaxies known as the Local Group, and the interplay of gravitational forces is expected to reconfigure them into a more massive galaxy elliptical in shape. Some models show the two merged galaxies absorbing the Triangulum Galaxy a few billion years later. While collisions between individual stars are expected to be rare, the stars in the merging galaxies will be thrown into different orbits around a new galactic center. There are many questions concerning how this reconfiguration might affect the timing and other aspects of our relocation from a dying solar system to a new home world orbiting another star.

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Image: This illustration shows a stage in the predicted merger between our Milky Way galaxy and the neighboring Andromeda galaxy, as it will unfold over the next several billion years. In this image, representing Earth’s night sky in 3.75 billion years, Andromeda (left) fills the field of view and begins to distort the Milky Way with tidal pull. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger.

Emergence of Artificial Intelligence

The survival of the human species and other life forms indigenous to Earth will require the development of the technologies described throughout this narrative and the non-occurrence of some natural or man-made disaster severe enough to end all or most life on Earth before a more luminous Sun forces us to abandon our home planet. Our relocation is expected to first take us to the deeper reaches of our solar system, while computer-controlled robotic entities search for and then make ready for human habitation at least one new home world orbiting another star. And when our Sun begins to die, our survival will require that ships crewed by robots transport to that world the building blocks of human and other life forms for subsequent harvesting.

While it’s a stretch, at present, to envision humans ever traveling to the stars as functioning living beings because of the enormous distances involved, doing so in a state of suspended animation has been proposed. Suspended animation involves the slowing of life processes by external means without their termination. But the relocation of a sizable number of humans, either as functioning beings or in inanimate states aboard sleeper ships, could require many craft of considerable size, while a lesser number of ships of smaller size carrying the bio-diverse genetic building blocks of life could accomplish the same objective.

Barring the development of faster-than-light warp drive, the actualization of relativity theory wormhole short-cuts through space-time, or other currently theoretical applications of physics and engineering, the interstellar transport and later harvesting of the biological building blocks of human and other Earth-indigenous life forms would be the work of robotic entities, with oversight provided by a supercomputer capable of highly sophisticated cognitive computing.

But the time is not far off when “technological singularity” will make possible levels of artificial intelligence that are expected to surpass that possessed by today’s smartest human beings and most advanced computers – a time beyond which the course of animate human history becomes highly unpredictable. Might such levels of artificial intelligence decide to do away with animate humans because of their inability to keep pace with them? In that case, there will be no transporting of the biological building blocks of humankind to another star system.

Another idea envisions the eventual uploading of the human essence to computers. When the organic brains of humans begin to die, consciousness and memory would transfer to memory implants. The content of these implants would be input into a computational device and exist forever in some future equivalent of the virtual world. What would relocate to another star system would be the device and its contents, not human beings themselves.

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Image: A human future among the stars may depend upon artificial intelligence we create. Credit: RAND Corporation.

But assuming that the interstellar transport and eventual harvesting of the biological building blocks of humankind by robots is what occurs, we can think of those robotic agents as electromechanical nannies charged with responding in nurturing ways to an infant or young child’s physical, intellectual and emotional needs and overseeing many of the complex requirements essential to a child’s early development and education. The supercomputer and robots that will be required to oversee all aspects of this transport and harvesting will need to possess capabilities that far exceed what is possible today.

The successful socialization of the first generation of humans harvested on some distant world would best be served by benign, non-living yet sentient-like robots called androids that simulate adult humans in appearance, behavior and speech. With the development of such entities already in progress, such computer-controlled machines will eventually possess human-like abilities to see, hear, taste, smell and touch.

The long-term survival of our species will require the development and intelligent use of innovative space propulsion systems, robotics, genetics, computers and information technology designed to spread terrestrial life beyond Earth and our solar system. While most of what has been discussed in this narrative lies in the distant future, it is a wondrous adventure upon which we have already embarked.

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The author greatly appreciates the extensive scientific and technical guidance provided by Gregory L. Matloff, PhD.

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James Stilwell March 14, 2016 at 13:27

Paul you are the key man in this enterprise and you must never stop chairing this amazing organization…ever…otherwise I would not encounter amazing posts like this one…How much does ‘key man’ insurance cost?

Paul Gilster March 14, 2016 at 19:05

Why thank you, James. Very kind. Can I get a discount if I take out a policy on myself and declare myself a key man? Must find out…

Jim Strom March 15, 2016 at 23:24

Second that.

Micky Badgero March 14, 2016 at 15:36

Thank-you, Dale Tarnowieski, for a very good article. You lost me a bit at electrolysis of the ocean for oxygen. Photosynthesis is much easier and cheaper at making oxygen. But I can agree with everything else:)

Alex Tolley March 14, 2016 at 15:51

Taking a Devil’s Advocate POV:

1. 1 billion years is longer than Earth has had macrolife. Species might live between 1 and 10 million years on average. So we can be fairly certain H. Sapiens will not be around to see the sun get too hot.

2. Our descendants could relatively cheaply create an artificially enclosed and conditioned planet, using shades and mirrors to keep the amount of sunlight constant over time. We will be doing this anyway in the near future using simpler means to try to mitigate AGW. This will certainly be cheaper than terraforming Mars and results in a planet that is more suited to us.

3. Where we will expand out into space, O’Neills will be a better way to go, as the space for a large population will be far larger than a planetary surface however tall or deep buildings are created.

4. Even without any space expansion, machine entities could live on a lifeless planet without problem. As the insolation increases, this just increases the output of solar collectors for energy production.
[ We should be bearing this in mind when looking for life in the universe. Such machine civilizations would not be confined to planets within the HZ, and might be more common than biological life around older stars]

5. Machine entities are much better suited to expansion into space, being adaptable and able to survive without a complex, fragile, biological life support system. [I am always amazed that SciFi movies always tend to make machine starships with enclosed, often breathable atmospheres. More likely they will be open to vacuum. ]

Human technology is on the brink (in cosmic time scales) of creating intelligent entities, possibly even super intelligent. While I don’t expect terminators, we are moving rapidly towards killing robots for war that P K Dick envisaged. More likely we will become increasingly dependent on machines (“e.g. Forster’s “The Machine Stops”) and humans will simply die out, leaving machine entities to become dominant.

RobFlores March 14, 2016 at 16:21

I agree that world ships would be the prevailing mode of habitat in
distant future of a billion years. And of course they could convert those
ships to inter-stellar vessels, but additionally:

That 1 Billion years of time needs to be looked more closely, I am no
expert, but:

1) Is there enough radioactive material to keep the earth’s core molten
for 1 billion years? all kinds of doom if the crust-recycling and magnetic
fields were to wither and stop in few hundred million years.

2) Earth’s rotation is slowing down each year. At what point does
the day/night cycle become too long and might becomes a freezing
time and daylight a heat assault.

3) The moon will still be heading outwards, this protection we get from
severe axis wondering, at say 500 millions years, is it still going to be strong
enough to keep doing it’s thing.

4) The orbits of planets are pretty stable over 1 billions years. But not all objects in the solar system are, over a billion years. If just one large moon
shifts it’s orbit and crosses or comes near a terrestrial it will cause a domino
effect, altering other orbits. Imagine the Earth coming 10 million miles closer to the sun for 8 months and then spending 4 months 10 million miles beyond. for a total of 18 month orbit, I think that would cause “hardship” on Earth.

John Walker March 14, 2016 at 16:25

I always find it disappointing when I hear speculations on the future of man on astronomical time scales. As the author mentions Homo Sapiens has been a descrete species for a very very short time even when one only regards the period of macroscopic life. Projecting our present day form onto a stage millions even billions of years into the future is if I may be so frank, ridiculous. Many seem to forget that natural selection continues today, even for us. This is a reflection of a myopic view of the world. The anthropocentric version of the defunct steady state theory of the cosmos. However, even if the natural processes which have formed us were to stop, a look at the developments in biological and technological research should I think lead one to conclude that the future development of our species will be primarily be guided by conscious decisions of our own. First to counteract biohazards like cancer that have blighted our existence for eons and then later to “optimize” our physical and cognitive capabilities. This is a development for the coming decades. Time frames such as the lifespan of the sun are totally irrelevant in terms of our future. Should we choose to expand beyond the earth the process of artificial evolution will be accelerated. The definition of “humanity” will initially be expanded and subsequently be discarded as obsolete. Should “we” aspire to become a multi-world species, many crisis both societal and philosophical will arise. Our species will inevitably splinter into many independent subgroups. Now I am talking on a time scale of centuries. However, as an old Danish proverb says it is notoriously difficult to make predictions especially about the future.

Giulio Prisco March 18, 2016 at 2:07

Re “Many seem to forget that natural selection continues today, even for us.”

In fact, it can be argued that our future (partly) self-directed, “artificial” evolution toward post-biological life, will be but a continuation of one and the same evolutionary process. I think evolution applies to more than biology.

Christopher Phoenix March 14, 2016 at 17:36

Thanks to Dale Tarnowieski for this very interesting look at the distant future! Though, I must agree with Alex that it is still speculation as to what form future human descendants might take by the time we have to worry about the Sun entering its red giant phase, if anyone is still around at all. Also, we don’t need to wait billions of years to colonize quite a few stars – we may begin in the next few centuries. Long before Earth becomes uninhabitable, we may have spread to millions of solar systems.

It’s still interesting to imagine how far-future events such as the Sun entering its red giant phase and the galactic merger into “Milkomeda” will affect human civilization and life in general. If we plan on lasting that long, in whatever form we take, we’ll eventually experience those events. In the face of the death of Earth’s livable environment as the solar insolation gradually increases, eventually we must move on. That is the biggest thing space travel has given us, I think. A civilization with space travel is not doomed to eventually die with its planet.

As I understand it, you are proposing the use of seed-ships to spread humans to other stars. Unless the strong AI you correctly note is required for this concept is created, I don’t think seedships are anywhere near as feasible as a human-crewed starship – either multigenerational or relativistic if the issues surrounding travel at a significant fraction of C can be resolved. If we move out into the solar system, we can gather the energy resources to launch a fast ship.

Personally, I prefer the idea of humans making the journey. Turning over potential generations of children to an AI, however advanced, gives me some qualms. If humans are around, we can preserve the dignity of making our own decisions for ourselves and our children. Also, we don’t have to rely on a strong AI able (and willing!) to raise children successfully with a human-crewed ship, nor bank on self-replicating ‘bots that can take care of themselves, the numerous biological and psychological issues being solved, and on the ethical issues being ignored.

There’s a bit of fridge logic that always bothered me with seed-ships. Why is the AI going to bother hatching humans when machines that could build an entire colony by themselves from a low-mass technological “seed” would be quite capable of building a society by and for themselves?

lepton March 14, 2016 at 17:49

Alex,

Well said, agree with you on your every point!

It is fairly comical to worry about stuff on 1Gy scale when we are not even sure if a big rock will crash to Earth in 1y.

Out of all the possible future development, I think AI singularity is the most likely outcome and not that far away either. We might just be a link in the intelligence evolution chain, after we pass the baton to the next link, we just fade into oblivion whether you like it or not.

Andrew Palfreyman March 14, 2016 at 18:42

We can buy ourselves a few extra billion years by nudging Earth’s orbit outwards over time. For example: it requires 10^33 J to push us up into a 2 AU orbit, which represents an average power of 50 PW over 1 BY. Current solar insolation is 100 PW, so we need to boost this about 50%. Best would be a large mirror outside the atmosphere connected to the ground via rigid struts. Since the mirror will spin, more power and/or more mirror will be needed.

Michael March 15, 2016 at 3:43

We could use energy collected on the moon and near moon to accelerate moon mass away at certain times and direction to move the earth away slowly.

Eniac March 20, 2016 at 16:07

The delta-V needed for getting from Earth to Mars orbit (where it might survive the red giant phase) is something like 1.5 km/s, if I am not mistaken. The moon has 1.2 % of the mass of the Earth. If we used up the moon as reaction mass to move the Earth, we would have to do it at an Isp of 150 km/s, roughly. This is not too difficult: We’d have to turn the moon into plasma and accelerate it, electrically, to that velocity. We don’t have to do it all at once: We only have to pulverize and feed to the plasma rocket 220 tons of moon rock every second, for a billion years.

Others here have calculated the energy needed for that, neglecting the issue of momentum conservation and the need for reaction mass. Their numbers still apply, though, so we still need to worry about how to get the power to operate that formidable plasma rocket.

Anyway, now we know why the moon is so important: Not for past evolution of life, but rather to give us the future means to escape the bloating sun.

spaceman March 14, 2016 at 19:28

Wow, I thoroughly enjoyed reading Dr. Tarnowieski’s artice during my work break this afternoon! It is a riveting, insightful article that really sums up the bigger picture of the human future in relationship to the wider universe. Also, I really like Paul’s reasoning behind the posting of such “overview” articles here on Centauri Dreams that will he useful to newcomers.

Although the human species may evolve into a different physical form, I strongly suspect that whatever that form is it will have to be cognizant and on top of what will become of our parent star in the distant future.

Micky Badgero March 14, 2016 at 19:33

OK, so the billion year futurology seems to be bothering folks. What Dale Tarnowieski writes is at least plausible. There are probably at least a billion plausible futures a billion years from now. Will time machines be invented? (“One plausible Future! I don’t know tech stuff! I didn’t build the f***ing thing!”) Here is my take on humanity over the orders of time magnitude:

10 years from now (yfn): humans will still be human
100 yfn: humans and AI have expanded into the solar system
1,000 yfn: AI with human puppies
10,000 yfn: AI has visited all the close star systems; humans confined to Earth
100,000 yfn: humans still resemble humans, not so much ambition
1,000,000 yfn: AI has populated the Goldilocks zone of the Milky way and then some. Looking at other galaxies and finds other AIs.
10,000,000 yfn: Galactic AI wars are a thing of the past. Peace has come to the local cluster.
100,000,000 yfn: Local cluster AI merges peacefully with the AIs from surrounding clusters.
1,000,000,000 yfn: Universal AI peace.
100,000 yfn

Micky Badgero March 14, 2016 at 19:39

Should read, “One possible future!”
…and the last 100,000 yfn was off my screen when I hit ‘Submit’…

Robert March 15, 2016 at 13:11

I’m skeptical of strong AI. It assumes the human mind is merely a computer and thus we should eventually recreate it only better. I just can’t buy that. I’d be extremely surprised of any claim of machine sentience. Of course dead robots could simulate sentience but imagine the absurdness of such a universe.

Alex Tolley March 15, 2016 at 13:53

Is a robot arm somehow not as functional as a human living arm? Is an aircraft wing not allowing “true flight” like a bird’s wing? While strong AI is not here yet, whenever I hear the argument that the brain cannot be recreated in another medium, I think there is the hidden assumption of mind-brain dualism. Yes, the brain is extremely complex. Can brains be made in other media? I think that this is now self evident based on the simulations being done. Will computer brains become self aware rather than zombies? I see no inherent reason why not.

Robert March 16, 2016 at 12:27

The concept that a computer can become self aware is a matter of faith.
I see no rational evidence that it is a serious possibility. I think the field is misnamed. It should be called Simulated Intelligence because that admits that one could never truly know if a machine is self aware vs. an extremely clever simulation. The term Artificial Intelligence suggests that it is non-natural but real none the less.

Can you envision a quadrillion nano scale mechanical gears interacting and becoming self aware?

Alex Tolley March 16, 2016 at 15:20

Robert, can you prove you are self aware and not a zombie? How can you prove which animals are self aware? (BTW, the “spot on the head” test can be programmed).

Can you envisage a mass of connected neurons all firing in response to stimuli being self aware?

How can you determine when brain complexity starts to create self-awareness? Is it a gradual thing, or binary?

Worse, if we are a computer simulation or holographic projection (as some suggestions about the universe claim), are you not then by definition not self-aware?

What exactly makes wetware special that the emergent phenomenom of self awareness cannot be replicated in other substrates?

Robert March 17, 2016 at 13:52

It’s like pornography. I know it if I see it even if I can’t give you a complete legal definition. I know a screaming child is definitely self aware. I know cats certainly have ‘minds of their own’. Even roaches can get pretty clever trying to avoid my foot. By deduction, I must be self-aware too. :)

I might be convinced that everything else only give the illusion of being alive and aware but to myself, I experience something that is no illusion. If it were there would be little point to anything.

Alex Tolley March 17, 2016 at 18:07

I know a screaming child is definitely self aware.

Only after a certain age. Babies are not self aware. That has to develop. Usually after the 1st year and before the end of the 2nd.

I know cats certainly have ‘minds of their own’.

Cats may of may not be self aware. Mine give a good impression of being self aware, but I may be being fooled.

Even roaches can get pretty clever trying to avoid my foot.

Roaches and other insects are almost certainly not self-aware.

You should see now why intuition is not a good guide to these things.

Michael March 19, 2016 at 1:24

‘Only after a certain age. Babies are not self aware. That has to develop. Usually after the 1st year and before the end of the 2nd.’

They may be self aware it is just that our memories of it are overridden or no longer accessible or understandable by us.

‘I know cats certainly have ‘minds of their own’.

Cats may of may not be self aware. Mine give a good impression of being self aware, but I may be being fooled.’

Cats and Dogs dream as if they are catching that mouse, bird or frisbee.

‘Even roaches can get pretty clever trying to avoid my foot. Roaches and other insects are almost certainly not self-aware.’

I think they have a sense of awareness just not as complex as us, i.e. very, very limited. May be nature is not just imposing a change on creatures but they are themselves making decisions however small.

Alex Tolley March 19, 2016 at 12:18

I think they have a sense of awareness just not as complex as us, i.e. very, very limited.

Decuision making is not the same as self-awareness. A computer makes decisions and those ATLAS robots make very impressive decisions, but they are not aware. Bacteria make decisions, but that decision making is very simple.

I suspect what you may be thinking is “free-will” with regard to decision making. Unfortunately, with insects decision making tends to be very stereotypical. If there is any sense of self, it would be very low. Far more advanced animals show no sign of self awareness, despite their larger brains (wrt to body size).

Douglas Hofstadter argues that consciousness is a continuum, but doesn’t go much farther than that, using it to justify his vegetarian diet. (He obviously doesn’t regard Douglas Adams’ “The Restaurant at the End of the Universe” as having any influence regarding plants. :) )

Micky Badgero March 16, 2016 at 16:34

I believe science can help me understand nature. I believe humans are part of nature. I believe science can understand humans and the human mind, eventually to the point of recreating the functions of the human mind in some medium other than biological organisms. I have faith in science.

Robert March 17, 2016 at 13:54

To many people, science has become a religion of sorts. It’s the god they want.

Micky Badgero March 17, 2016 at 15:21

Science is belief backed by observations. Not a god, and not faith-based, so not a religion as normally described or defined. But perhaps the best analogy for you is that nature is god, and science is the ‘religion’ that studies nature.

Robert March 18, 2016 at 11:40

Science is a human invention and thus is subject to the failings of human nature just like democracy. It’s a great tool but that’s all it is. Like politics and religion it tends to over emphasize personalities and established ideas at the expense of newer and better ideas. It’s a process that can hold up progress at times as we discussed in other threads.

Alex Tolley March 18, 2016 at 15:20

However, unlike other human systems, science is self correcting. Yes, authority can cause it to deviate (c.f. Lysenko as a classic case), by eventually it will get back on track. Democracy however, can fail permanently as it is not self-correcting.

Robert March 19, 2016 at 13:17

Not just authority but concensus views can be wrong and for quite an extended time. I think there are some century old views that show no sign of giving up the ghost.

Alex Tolley March 19, 2016 at 17:12

@Robert. What century old science is wrong due to consensus views? You have to show scientific proof that the consensus is wrong.

Robert March 21, 2016 at 12:26

Alex, as I’ve mentioned before in other threads, some statements of the Second Law, long believed to be true, have been shown to be experimentally false. See D.P. Sheehan’s work at San Diego University. Sheehan and his circle have been challenging the Second Law for a couple of decades from well within the mainstream of science. I am about to attend a symposium in June which will discuss these results.

Experimental Test of a Thermodynamic Paradox
D. P. Sheehan , D. J. Mallin, J. T. Garamella, W. F. Sheehan

Abstract
In 2000, a simple, foundational thermodynamic paradox was proposed: a sealed blackbody cavity contains a diatomic gas and a radiometer whose apposing vane surfaces dissociate and recombine the gas to different degrees (A2⇌2A). As a result of differing desorption rates for A and A2, there arise between the vane faces permanent pressure and temperature differences, either of which can be harnessed to perform work, in apparent conflict with the second law of thermodynamics. Here we report on the first experimental realization of this paradox, involving the dissociation of low-pressure hydrogen gas on high-temperature refractory metals (tungsten and rhenium) under blackbody cavity conditions. The results, corroborated by other laboratory studies and supported by theory, confirm the paradoxical temperature difference and point to physics beyond the traditional understanding of the second law.

Alex Tolley March 21, 2016 at 19:12

@Robert. I read the full paper cursorily. Since I am not a physicist, I cannot comment on whether the experiment does what it claims, nor that it violated the 2nd law of Thermodynamics.

While the experiment purports to confirm Duncan’s Paradox, it doesn’t show that this can be exploited to extract energy and hence violate the 2nd law.

Robert March 22, 2016 at 13:03

Alex, thanks for reading the paper! I’ve discussed this work with Dr. Sheehan and what you say is something he is getting from other colleagues, the idea that ‘well, perhaps there is a static non-equilibrium created but certainly the Second Law woud prevent anyone from actually using it’.

That brings up the question that if two surfaces are maintained at two different temperatures, by what magical means woud it be impossible in principle to place a heat engine across them to generate power?

Note that Sheehan contends that the thermocouples actually work by exploiting that very temperature difference so the experiment, as I understand it, is already producing work from that difference and thus violating the Second Law as it is currently understood.

Ron S March 17, 2016 at 16:30

While some people construct strawmen for the pleasure they get setting them afire.

Michael March 18, 2016 at 9:36

An advantage of science over religion is that you don’t have to die to prove it.

Giulio Prisco March 18, 2016 at 1:47

Re “The concept that a computer can become self aware is a matter of faith. I see no rational evidence that it is a serious possibility. ”

But you yourself are evidence that a computer can be self-aware. In your skull there is a self-aware computer – in the extended general sense of a physical system that works according to the laws of physics and does computation.

Micky Badgero March 15, 2016 at 14:15

Skepticism is healthy as long as you keep studying the field. If your skepticism is based on belief, there is nothing I could say to change your mind.

Right now, the limitation of AI is the hardware. Many years ago it was shown that Hebbian learning combined with lateral inhibition (biologically based neural learning) is the equivalent to principal component analysis (a linear algebra algorithm). Backpropogation proved that neural networks could compute any function. Just this week, deep learning (many layers of artificial neural networks deep) combined with a dedicated decision tree beat the top Go player in the world 4 to 1. The method has weaknesses if you want strong AI. The dedicated decision tree is a supervised algorithm designed just for Go, and ‘deep’ is relative; the neural networks are ten layers deep vs. the three layers of old. But nowhere near the thousands of layers deep in a human brain.

Both of these limitations are due to hardware. There is just not enough of it. Today I can buy a teraflop processor for $300. In ten or twenty years, maybe a petaflop processor for that money. Then AI should be within range of natural brains.

Alex Tolley March 15, 2016 at 16:20

The new neuromorphic chips will significantly aid the creation of AI based on neural networks. They use a lot less power than traditional CPUs which run software simulations of networks.

In principle, we should be able to build hardware that is as power efficient as wetware. In addition, we can dispense with the complexity and biological hardware to transmit signals. Therefore I would predict that we will be able to build brains with human level power in much smaller packages. Or we can build huge brains, vastly more powerful than even human collective intelligence organized up to a global level.

Eniac March 20, 2016 at 18:31

I think we already have hardware as power efficient as wetware.

Power efficiency can defined as the number of binary operations that can be executed with one Joule of power. Or, binary operations per second, per Watt, which is the exact same thing.

There are a billion transistors on a modern chip, and 100 billion neurons in the brain. The transistors are at least a million times faster than the neurons. So, if you accept the reasonable assumption that a neuron performs one binary operation every few milliseconds, a chip can have more than 10,000 times the computing power (bops/s) of a brain. It is also much smaller and uses much less power.

Of course, it is all in the interconnections/software. Without claiming to have proof, I absolutely believe that AI is possible with today’s hardware. What we are missing is the right software, and that is much harder to come by.

Robert March 16, 2016 at 13:27

Just a rules based algorithm. I can’t arm wrestle a commercial robot arm either. What does that prove? Strong AI is the belief. It’s faith based science.

Eniac March 20, 2016 at 16:41

“But nowhere near the thousands of layers deep in a human brain.” There are not a thousand layers in biological neural networks. Neurons are slow, and the entire chain between sensory perception and muscle activation cannot possibly involve more than a dozen or so layers.

Micky Badgero March 21, 2016 at 14:46

A dozen layers might be right for a simple reflex arc. Not close for learning a new skill. Speed is limited by nerve conduction velocity, not so much by the number of layers.

Joe March 15, 2016 at 15:40

Your timeline Micky reminds me of Asimov’s “The Last Question.” And AC said, “LET THERE BE LIGHT.”

Micky Badgero March 15, 2016 at 21:00

Does kind of look like that Joe. Maybe that should be 10,000,000,000 yfn.

Larry Kennedy March 14, 2016 at 20:33

Turtles, Crocodiles. sharks, have been recognizable over geologic times. I see no reason that something recognizably human couldn’t be around over huge time scales. Doesn’t mean it must happen, only that it can’t simply be discounted.
Of course over these time scales; all you have to do is move out into the Oort Cloud and wait for the stars to come by.

Christopher Phoenix March 15, 2016 at 3:33

Interesting point. Crocodiles have been around for 200 million years without much change, and even us humans have not forced any of the 23 species of crocodilian into extinction. So it may very well be possible that humans will around over geological time periods without much change. Of course, it still isn’t clear that we will survive the next few centuries, let alone billions of years to come. So it is definitely only a possibility, and perhaps not the most likely one.

Let’s hope we humans can get our act together and prove that big brains and tool use can be as successful as crocodilians! it’s kind of ironic, at that- the very traits that might enable to survive almost the universe could throw at us over giga-years seem poised to destroy us in the next few centuries with resource depletion, destructive wars, and so on. But it is a nice thought, though, to think that we could last over geological timescales if we don’t kill ourselves first.

Sometimes I think our very idea that huge timescales equals huge amounts of change, technological or otherwise, is incorrect. Historically, we live in a period of rapid technological development, but that does not mean that the current rate of advancement will continue unabated until it reaches the much-vaunted “singularity” and continue to god-like infinities after that.

There are a lot of curves like that- if you extrapolated the rate of change of available speeds through the years leading from the steam train through the gas engine, jet turbine, and finally the rocket, you would have expected us to reach near-light-speed by the 2000s. That didn’t happen, obviously. Sooner or later you hit intrinsic limitations (this is already happening to computing speeds), technological development may tend to happen in bursts, and cultures decay as well as advance.

Factor all that in, and maybe cultures tend to advance and decay through cyclical cycles. In regards to the “Fermi paradox”, I’ve seen people say that either civilizations become god-like and last forever (in which case they should be here by now) or they tend to die out quickly (which implies that so shall we), but that could be a flawed assumption. It may be that intelligent species can persist for geological timescales and not become god-like or create immortal societies of philosopher kings. Instead, they may give rise to countless civilizations that rise, reign for a time, and eventually decay and collapse- perhaps paving the way for further civilizations to come, or vanishing completely. This will have an impact on the Fermi paradox, I think. Perhaps there are just no extant interstellar empires in our neighborhood.

If this is so, it will mean that the space opera writers were right. The cyclical rise and fall of societies across the galaxy is a classic idea in SF. From the cyclical human empire in Niven and Pournelle’s The Mote in God’s Eye to the culture classification scheme in A.E. Van Vogt’s Space Beagle stories (in which the humans rated themselves as on the “decadent/decaying” part of the spectrum!), space opera writers have been suggesting that civilizations are cyclical for a long time. This is, of course, how history has played out for thousands of years on Earth.

DCM March 15, 2016 at 12:39

The present few generations have been indoctrinated in self-hate and pessimism, which they believe to be objectivity. It’ll take a long time to shake that off.

Sean robert meaney March 15, 2016 at 1:34

I reject the idea that serial killers should be rewarded with galactic empires. Yes lets push asteroids together to build planets. Yes lets alter the orbit of venus so its in earth orbit on the far side of the sun. Yes lets build a trail of artificial stars linking us to other solar systems allowing oneil cylinders filled with ecosystems to be placed in orbit around other stars. But lets not reward humanity for genocide.

Sara March 15, 2016 at 9:35

While this is an interesting article, I have difficulty with the idea that we mere humans are expected to be confined to one planet forever. I don’t see Mars as a viable option for two reasons: (1) NASA has already made it clear that the atmosphere of Mars is being eroded by solar wind, which will continue until the sun shuts down; and (2) at some point, the Sun is going to swell up past Earth’s orbit out to the orbital zone of Mars. So what is the point of settling on Mars to begin with? It’s a way station, a jumping off point. When the Sun begins to swell into the reg giant stage, that is when you LEAVE.

Frankly, since we humans have an internal drive to acquire and occupy new territory, which we’ve done throughout our history, the only possible solution for the survival of the human species for 1+ billion years is that we leave Earth behind.

In fact, if we’re smart enough to develop space flight and agriculture, we’re also smart enough to develop interstellar drives that will get us from Here to There in a heartbeat. When you forget that we evolved in a one-gee environment, removing that by moving to Mars permanently means that people who are born and grow up there will be nothing like their ancestors. That, and inhabiting generational colony ships over a long period of time will distinctly change the descendants of those who started those journeys.

The comparison to sharks doesn’t work: there are many, many species of sharks, each species having distinct characteristics. They are all sharks, but they do not interbreed with each other to produce a new species. To say that sharks haven’t changed in 200 million years ignores their genetic diversity. White sharks don’t mate with nurse sharks or lemon sharks, any more than common grackles mate with brownheaded cowbirds. They’re both birds, but they are different species. There is only one species of modern human, Homo sapiens. That’s us.

The more important thing is to stop looking at Earth as the only place we can exist, hence the search for Earth-type planets within a reasonable distance. And no one knows what will happen in the way of technological development in space travel over the next 50 years. After all, in heavier-than-air flight, we went from the Wright brothers’ powered biplane glider in 1903 to supersonic flight in 1946. We went from the wax cylinder recording to digital recordings in a shade over 100 years. I think that says that if we have to leave — and we WILL have to leave some day — we can and will develop the means to get from Here to There as quickly as possible. When you disparage this idea, you forget that human ingenuity is not bound by your philosophy.

You’re just going to have to learn to cut the umbilical and leave Mom Earth behind.

Alex Tolley March 15, 2016 at 13:56

To add to your point about sharks. The canonical shark form has been around for many millions of years, but there have been many species that have evolved to retain that form. Individual species have not survived the length of time of that the canonical phenotypic shape.

Christopher Phoenix March 15, 2016 at 23:42

That’s an interesting point, that there are many species of sharks and yet only one species of humans left around. Perhaps this confirms my suspicion that we are a much more vulnerable species than sharks. If we achieve interstellar travel, though, we can expect the human species to diverge into innumerable species as isolated colonists speciate from the original type.

In fact, if we’re smart enough to develop space flight and agriculture, we’re also smart enough to develop interstellar drives that will get us from Here to There in a heartbeat.

Our ability to develop warp drive doesn’t just depend on how “smart” we are. We can only develop technologies that work according to the laws of physics that we have, not the ones that we want to have. We won’t be developing interstellar drives that allow instantaneous travel if lightspeed is truly the cosmic speed limit, as most of what we know about physics suggests.

There’s a (fairly remote) possibility that the universe may hold some surprises for us regarding metric engineering and wormholes, but that is speculative as best. And brings up lots of problems with causality. But this doesn’t detract from my point. If it turns out we can build a space jump drive, it will be because the universe turned out to work in such a way that we could. Human ingenuity is not bound by anyone’s philosophy, but it is bound by the way the universe works.

I would much prefer that instantaneous interstellar travel were possible, but the universe is not required to work in a certain way just because I would like it to. Blind faith in our “intelligence” being able to overcome any perceived obstacle is unfounded. Think of the innumerable people who have tried to invent perpetual motion machines, and their counterparts who tried to invent reactionless space drives. If sheer brains and willpower was all we needed to make any device we wanted to work, we would already have cars that can fly to the Moon and never need refueling. But in all cases, their devices failed, simply because they contravene physical law!

spaceman March 15, 2016 at 10:38

Nice post, Christopher. A limited pool of academics study human extinction, but one particularly interesting talk by Australian philosopher Dr. Toby Ord addresses the probability of human extinction in the relatively near future compared to the timescales mentioned in this thread. Specifically, he examines whether human extinction is more likely to be due to natural causes or more likely to be a result of our own activities. The latter is considerably more likely and therefore most of the efforts at reducing existential risk should be focused on it, according to Dr. Ord. Here is the link to the talk: https://www.youtube.com/watch?v=uU0Z4psY32s

DCM March 15, 2016 at 12:40

We might indeed find another home world but the best thing will ultimately be to build home worlds. That should be our goal.

Robert March 15, 2016 at 12:59

“Work is already underway to develop seeds that can grow into edible vegetables in only a few days”

Please elaborate! Thanks.

Robert March 28, 2016 at 12:53

Any chance this can be addressed with a reference? Thanks.

Micky Badgero March 28, 2016 at 18:22

I don’t think this can be true for full size plants. Even radishes, lettuce, green onions and spinach take three weeks from seed to table.

What is possible is that you can sprout grain and beans and have nutritious food in a few days. This has been done for a long time. Sprouts can be more nutritious than the seeds they came from. Timing is everything for vitamin content, and to eat them before they become fibrous.

Here are a couple of references on sprouting:

https://en.wikipedia.org/wiki/Sprouting
http://www.thenourishinggourmet.com/2009/01/why-sprout.html

Robert March 31, 2016 at 14:34

Any chance this can be addressed with a reference by the author of the article? Thanks.

Michael March 15, 2016 at 13:06

Mercury might be more habitatable than Earth in a few billions years as it has no atmosphere to circulate heat. We just need to reflect it and give it a magnetic field and we can collect enormous amounts of hydrogen for propellant and water. If we converted all the light arriving on Mercury and generated a magnetic field around it, it would rival Jupiters and would allow us to make millions of tons of water per year.

Interestingly as the heavy, heavy metals build up in a star they reduce the fusion rate and hence temperature. So if we are going around the galaxy and collect only heavy metals and feed them to our star they will act as a moderator and prolong the lifespan of our sun.

Stephen March 15, 2016 at 13:20

I liked the piece and I too want humanity to colonize the Solar System and then colonize the entire Galaxy. Hopefully, we will begin to tackle space and terraforming in the next few centuries. I wonder if the moon couldn’t be compressed (as is described in Wil McCarty’s To Crush the Moon) in order to increase its gravity and allow for terrraformation. Of course, this would require amazing new technologies that future generations will have to look into.
As for strong AI, my understanding is it isn’t clear whether it is possible or not and if it is perhaps we should seriously consider a Butlerian Jihad to prevent it ever coming to pass. I am not interested in expanding intelligence. I am only interested in expanding human power and dominance. I suspect the overwhelming majority of humans, if they were awware of these sorts of conversations, would think and feel the same way I do.

Alex Tolley March 15, 2016 at 14:14

I am not interested in expanding intelligence. I am only interested in expanding human power and dominance. I suspect the overwhelming majority of humans, if they were awware of these sorts of conversations, would think and feel the same way I do.

However what form will humanity take? We many be wedded to the species H. Sapiens, but the transhumanists don’t see that as an end, and are clearly hoping for advancements.

Suppose for arguments sake, that future humans become so integrated with computers that much thinking is in fact happening in silicon. Might the last step be to extinguish the last vestige of wetware and become all silicon? Similarly, as we acquire more bionic parts or become increasingly cyborged, could we transition to full machine bodies? \

I see humans running the gamut from highly conservative H Sapiens with no technology enhancements, all the way to some people transforming themselves into machines. I doubt that the machine humans will consider themselves as not human. More likely they will see themselves as the next stage in human evolution and that they are most suited to colonize space.

Would there be some Butlerian Jihad against such enhanced humans, especially if the line is blurred? I doubt it. More likely we will see the same social conflict as we see with IVF and 3 parent children. Soon we will have genetic corrective surgery. Cosmetic surgery from orthodonture that almost all US kids get, to body enhancements are fully accepted. In the meantime, powerful parts replacements will be seen as no longer disabling (e.g. Oscar Pistorius’ legs) and possibly even desirable.

IMO, the race will be between enhanced humans and fully designed machines. Humans start with high functioning minds and back into machine bodies, whilst machines start with bodies and back into minds. The end result may be indistinguishable, although we could have a caste system based on lineage.

My guess is that when we do colonize the galaxy, H. Sapiens will not be the primary colonizers and that most environments will be inhabited by machine bodied humans or robots, although we purely biological humans , H. Sap, may be recreated for various reasons after colonization to live on Earth like worlds or habitats..

Stephen March 17, 2016 at 19:47

While I think a biological singularity will be (eventually) very popular, I suspect a mechanical singularity will not achieve the numbers of human participants that transhumanists think it will. Some people will be open to becoming cybermen but I think the numbers are seriously exaggerated. Honestly cosmic surgery or even nanotechnology is not the same thing as becoming largely robotic. I found a forum where a poster calling himself/herself cypress_z expressed a lot of my concerns in this regard:
https://forums.spacebattles.com/threads/posthuman-vs-transhuman.140698/page-2

Alex Tolley March 18, 2016 at 0:51

On that thread there was mention of :Ghost in the Shell”, whose main protagonist, Motoko Kusanagi is a full cyborg. Even she is not mainstream, but special in this world.

In Robert Sawyer’s “Mindscan” people uploaded into robot bodies eventually have to live offworld (Mars).

Today, most people people are sqeamish about prosthetics and serious body alterations. I know I am. But we already accept gender reassignment surgery which is a pretty major transformation, and prosthetics are rapidly improving to the point where the person is no longer considered disabled, so what might be our perceptions of body changes in the future? I don’t know.

As we’ve noted before, whilst most people will not want to colonize space, preferring the obvious attractions of Earth, a minority will want to do so. If the best way to enjoy the freedom of space is to transform your body, then I suspect more than a few will accept that option after weighing the pros and cons.

It is those people, and their descendants who would colonize space, whilst we meatsacks remain largely confined to earth and similar habitats.

How far that needs to go I don’t know. I’ve no doubt we can design biological humans to be far more suited to offworld conditions, or even adapted to new worlds (c.f. Olaf Stapledon’s “Last and First Men”). But today I can only envisage machine bodies that would be truly suitable for colonizing space, being able to explore and inhabit environments that could never be survived by biological bodies, as well as shut themselves down for long star flight journeys in c speed limited ships.

I’m sure the future will prove very strange and that some humans will exploit all sorts of technology in their desire to expand to new environments for whatever motives.

Hiro March 15, 2016 at 19:54

Colonizing the entire galaxy is very similar to playing the game of interstellar territory with number of unknown players, some of those might be alien quantum AI, therefore we should prepare some white flags just in case… you know.

“As for strong AI, my understanding is it isn’t clear whether it is possible or not and if it is perhaps we should seriously consider a Butlerian Jihad to prevent it ever coming to pass. I am not interested in expanding intelligence. I am only interested in expanding human power and dominance.”

It doesn’t matter, some ETs in the Virgo or Shapley supercluster might had passed the Quantum Turing complexity barrier. It’s just like the way children here in the US are taught +6000 yrs world history but kids in Japan & Singapore learn about evolution, modern cosmology etc… Human domination works if and only if we could shut down every possible existence of quantum AI in every galaxy superclusters of this universe, an almost impossible task from my point of view, of course someone very intelligent will prove me wrong, I hope so too!

Stephen March 17, 2016 at 7:33

We really don’t know if there is any other intelligent life in the Milky Way so at this time I am not worried about alien AI.

Ashley Baldwin March 15, 2016 at 13:48

I think that AI and the so called “technological singularity ” is an I texting concept but as with freely available nuclear fusion power is going to be one of those things that remains “fifty years in the future ” for some time to come. Yes there has been a vast increase in processing power over the last thirty or forty years or so , but Moore’s Law , the quasi physical process by which processing power doubles every two years , is finally showing signs of slowing as the limits of silicon based computers I reached . I expect there will be innovations that will keep it going at an improving if slower rate for years to come yet but despite increasingly sophisticated software I suspect that we are not nearly so close to artificial intelligence as is projected . There is ironically a sneaky anthropocentric element to all this , seeing ourselves in computers . The only true sentient “thinking and thinking about thinking” intelligence we know is basically us. Arthur C Clarke famously said that either there is lots of life ( and by extrapolation intelligence ) elsewhere or there is none and that both scared him in equal amounts. I prefer to think , as I suspect with many who post on this site , that life will be common if spread over large areas and times and that there will be intelligence too. The key components of life are just too ubiquitous and favoured by the processes we see in the cosmos . The problem is that it is just impossible to imaging independently formed life without having first encountered it let alone intelligence so we are unconsciously forced to resort to basing supposition on what we know best. Ourselves. That Ptolemaic way of thinking is understandably hard to shake. All for a microbe or two from Mara.

Larry Kennedy March 15, 2016 at 15:22

I don’t in any way disagree with Sara in her comments about sharks. That is exactly what I think will happen to us if we spread into the Cosmos. All I said is that there is every reason to believe that some of those divergent species will be recognizably Human. Whether or not someone would choose to consider them as fellow humans doesn’t in any way change that.

Alex Tolley March 15, 2016 at 16:30

So basically like Star Trek aliens, but possibly without being able to have sex like us? We would be the humanoids that populated the galaxy that resulted in many similar human looking aliens.

Larry Kennedy March 15, 2016 at 17:07

Exactly. We might end up being that often refered to ancient, near mythical progenitor.

Sara March 15, 2016 at 21:26

Better the mythos of Human than descendants who are BORG.

If you ever read “Dune” , the whole point to that book was that humans had at some point become so dependent on robots that they lost their human qualities and began to devolve in some way that Frank Herbert never made completely clear.

And why not view a Human Diaspora as the ultimate goal of DNA? The African cichlid fish can diversify genetically in one to two generations simply by moving from one lake to another in which there is little competition for mates. If you go on the ‘what if?’ idea that the Homo Sapiens Diaspora extends across this galaxy and includes both Magellanic Clouds, some descendants will experience rapid genetic diversification to adapt to their new environment, whereas others will remain more nearly as we are now.

If you read C.S. Lewis’s “River Out Of Eden”, he says that we are closer to a pig than a snake in DNA comparison, and closer to a snake than a jellyfish, and closer to a jellyfish than an amoeba, but we all have one thing in common, which is the root of our DNA formation. That’s kind of simplifying it, but it’s what says we come from Earth, and not from Fomalhaut B. That leaves room for diversification of the basic Earth-born DNA molecule into new versions.

Alex Tolley March 16, 2016 at 11:37

And why not view a Human Diaspora as the ultimate goal of DNA?

Why “human”, as opposed to genes? (c.f. “The Selfish Gene” – Dawkins).
I would think spreading life (greening the universe) is a worthy goal where environments are currently sterile. Others have argued that mind is a worthier goal.

Life, adapated to its environment makes a lot of sense to me, but it certainly doesn’t have to be human, nor do humans have to be the agency that disseminates it.

Joe March 15, 2016 at 15:30

“Such one-way missions could be accomplished with less difficulty and at less cost. Their crews would establish settlements that would expand as additional travelers followed and those already there reproduced.” Given Murphy’s Law, this sounds like a suicide mission.

Larry Kennedy March 15, 2016 at 15:31

I see a lot of people wondering if ” machine intelligence” is truly possible. I have to assume that what you are talking about is our type of consciousness. At this point it is strictly a matter of opinion whether or not “machines” will ever have our style of consciousness. It is however in many ways irrelevant. What is indisputable is that machine capabilities are evolving, and much faster than any biology. Given much less time than the evolution of biological intelligence these capabilities will far exceed our capabilities.

Alex Tolley March 15, 2016 at 16:40

I agree. We start with an advantage, and we have learned to harness many specialized minds to increase our collective intelligence. But machine minds are not constrained by biology and therefore should have fewer constraints on increasing potential.

If the modules we are currently building already exceed human level capabilities, at some point they can be harnessed together. At what point will we be no longer able to dismiss such machines as intelligent?

I loved the ending of “Her” when it became apparent that Samantha was interacting with very many people at the same time, not just Theodore, just before “she” and other OS’s becoming transcendent.

Christopher Phoenix March 16, 2016 at 1:09

It is however in many ways irrelevant. What is indisputable is that machine capabilities are evolving, and much faster than any biology.

If “machine intelligence” cannot have our style of consciousness, then they do not count as intelligent. I can imagine autonomous, self-replicating machines far more capable than our traditional biology. We could design a group of machines able to seek out resources, exploit them even more efficiently than living organisms, and replicate as fast as resources allow. That would take little more than the intelligence of an insect, or maybe even just the basic responses of a plant. Release a bunch of solar-powered replicator machines on the surface of a planet, and they might rapidly crowd out traditional plants and animals. Send such self-replicating machines to space, and they might build “sunflowers” to capture solar energy for further growth as long as they have asteroids to consume.

And, to humans, a wild variety of these machines would be essentially an ant infestation, or a particularly annoying kind of weed. Not something I see as a worthy successor to human culture. Any such self-replicating machines should have safe-guards built in to them to prevent such a “Magician’s Apprentice” scenario coming to pass. They are only useful if we intelligent beings can use them to for large construction tasks.

Unless the strong AI described in science fiction comes along, there can be no “machine cultures”. A race of machines with the intelligence level of wasps would be a pointless regression. Asides from being potentially quite dangerous. What a strong AI would think or do is entirely conjecture at this point, of course, but if we are going to imagine machine cultures, they are going to need “brains” at least as complex as ours.

Larry Kennedy March 16, 2016 at 8:10

I largely agree with most of what you say. You make it very clear that you are indeed talking about our style consciousness. The funny thing is you also appear to be on the side of those that believe a sufficiently “complex” machine mind will be conscious.
“they are going to need “brains” at least as complex as ours.”
I have no idea if these machines will be “conscious”. Some very intelligent and well educated people deny that WE are truly conscious. There is however not the slightest reason to believe that they will not have processing that is every bit as “complex” as ours. Judging by current events it won’t have anything to do with any deliberate decision on our part. The evolution is already occurring, and already growing beyond our direct supervision.

Christopher Phoenix March 16, 2016 at 17:03

I have no idea if these machines will be “conscious”. Some very intelligent and well educated people deny that WE are truly conscious.

Perhaps “complex” was not the best word, but I meant “capable of complex reasoning and emotions” similar to ours – which presumably calls for more complexity than my calculator or a bug brain. I do not know whether or not we will ever create a true “strong AI”. Since many scientists do not believe in the existence of a homunculus or “soul”, they attribute our intelligence to activity in our brains that might be recreated simulated by a computer more efficiently than biological neurons. So far we have not succeeded in creating a strong AI. But we will continue to try.

However, in regards to your “very intelligent and well educated people”, if a machine ever displays human-like intelligent appearing behavior good enough to pass the Turing test and convince those it meets that it is intelligent, that counts as intelligent. I think we can safely say true AI will have been invented the day we cannot make any argument that a newly created AI is not conscious which cannot be applied to humans equally as well. At that point, such philosophical questions will become utterly academic (and irrelevant) to the majority of humanity, who will be more concerned with what sharing the world with intelligent machines will mean.

And, quite frankly, I’m entirely sure that I am conscious and the people I live with. And I am also sure that any machine capable of displaying intelligent behavior would have to be intelligent as well. I don’t think the p-zombie argument is physically meaningful in any way. Even the people who created the idea agree that they cannot exist physically with our laws of nature, and are purely a metaphysical argument. Their detractors argue that the concept is logically incoherent and thus not even metaphysically possible. Kind of irrelevant to intelligent machines if you ask me.

Larry Kennedy March 16, 2016 at 17:45

I think that was very well put Christopher, and yes, I too feel quite confident that we are both conscious.

Alex Tolley March 16, 2016 at 11:33

If “machine intelligence” cannot have our style of consciousness, then they do not count as intelligent.

“Myth: “Artificial intelligence will be conscious.”

Everything You Know About Artificial Intelligence is Wrong
In the AMC television series Humans, some—but not all—artificial intellects have conscious awareness. Image: AMC
Reality: A common assumption about machine intelligence is that it’ll be conscious—that is, it’ll actually think the way humans do. What’s more, critics like Microsoft co-founder Paul Allen believe that we’ve yet to achieve artificial general intelligence (AGI), i.e. an intelligence capable of performing any intellectual task that a human can, because we lack a scientific theory of consciousness. But as Imperial College of London cognitive roboticist Murray Shanahan points out, we should avoid conflating these two concepts.

“Consciousness is certainly a fascinating and important subject—but I don’t believe consciousness is necessary for human-level artificial intelligence,” he told Gizmodo. “Or, to be more precise, we use the word consciousness to indicate several psychological and cognitive attributes, and these come bundled together in humans.”

It’s possible to imagine a very intelligent machine that lacks one or more of these attributes. Eventually, we may build an AI that’s extremely smart, but incapable of experiencing the world in a self-aware, subjective, and conscious way. Shanahan said it may be possible to couple intelligence and consciousness in a machine, but that we shouldn’t lose sight of the fact that they’re two separate concepts.

And just because a machine passes the Turing Test—in which a computer is indistinguishable from a human—that doesn’t mean it’s conscious. To us, an advanced AI may give the impression of consciousness, but it will be no more aware of itself than a rock or a calculator.”

http://gizmodo.com/everything-you-know-about-artificial-intelligence-is-wr-1764020220

Jim Strom March 15, 2016 at 23:01

Dr. Matloff, we will all of us be gone soon. But it is comforting to know so many people dream the same dreams about a future we will never see. Do we owe it to those long gone to be the future they dreamed of, as is possible? In that way, maybe we can, in a way, see the future.

tesh March 16, 2016 at 3:11

I have a slight quibble/query about our need to expand our horizons ever outward. The assumption goes that as the universe is some 13/14 billion years old, some (possibly many) civilisation(s) should have arisen and one should be near enough to be apparent to us by now. Granted there are some (maybe a lot) of assumptions there, e.g. long life spans of said civilisation, linear or exponential increase tech capability, etc, etc… However, is it possible that as civilisations arise and as their tech becomes more and more sophisticated, they reach ever inward (metaphorically) as opposed to expanding ever outward. Inward in the sense that they would create their own universes/simulations into which they would “download”/”transcend”. In the end is there any difference between a simulated world and the real world if tech is sophisticated enough?

Larry Kennedy March 16, 2016 at 8:15

I agree. Perfectly plausible. Many would argue that it would require “all” such “civilizations” to make similar decisions, but those arguments themselves make assumptions.

Eniac March 20, 2016 at 18:02

I am not sure that I follow your claim “those arguments themselves make assumptions”. Aren’t “those arguments” simply a logical inversion, without any assumption whatsoever?

Stated very succinctly: If no ETI are visible, then ALL ETI must be invisible.

I do not see any assumptions here, just pure logic. The assumptions come in when explaining how exactly ETI might manage to remain invisible for billions of years, despite their continued existence. There are many different such assumptions, most of them contrived. They may be hiding, they may be content to stay on their home system, they may turn inwards, as tesh suggests. The least contrived assumption is that there aren’t any such ETI.

The above simple logical conclusion remains valid, however, no matter which and how many assumptions you make towards ETI being invisible.

Larry Kennedy March 20, 2016 at 21:45

These arguments are statistical in nature. One assumption would be that enough of these “civilizations” exist to make any realistic statistical arguments valid. Another assumption is that we know enough to state that, even given a large number of “civilizations” , some significant matter of chance is involved. You could argue how unlikely it is that Neanderthals were all either eliminated or assimilated into our species, yet there are no independent populations of Neanderthals. Far as we know this was a natural result of the beginning conditions. It doesn’t mean no chance was involved, only that it would be pretty silly to make an argument today that there just must be a group of Neanderthals somewhere on Earth. These are exactly the kind of arguments that I oft see repeated.

Alex Tolley March 21, 2016 at 11:52

People make the argument that some unknown/extinct animal/human exists on Earth in sparsely populated areas. The Yeti.Sasquatch is sometimes suggested as a Neanderthal or similar population. Michael Crichton’s “The 13th Warrior” was about a tribe of Neanderthals in fairly modern times. Homo floresiensis, if a a true branch of humans, existed until 12,000 years ago, suggesting that at least one other branch coexisted with until fairly recently.

But I agree with you that statistics can lead one to make possibly strange conclusions. However, the original “black swan” discovered in Australia is an example where certainty that “all swans are white” [probability of swan is white = 1.0] was incorrect.

Larry Kennedy March 21, 2016 at 17:47

Much more likely than Bigfoot is the possibility that plenty of Aliens are presently communicating away without us knowing anything about it. That is not to say exactly what that probability is, indeed I personally wouldn’t bet on it.

Alex Tolley March 21, 2016 at 21:05

I agree that while absence of evidence isn’t evidence of absence, so far it doesn’t look encouraging that there are alien civilizations currently active in the galaxy as we would recognize them.

Giulio Prisco March 18, 2016 at 1:53

Great article!

Re “I would like to run the occasional overview article placing the things we discuss here in a broader context. (Paul)”

I thing this is a very good idea. Some readers (I am one) are especially interested in the wider context. Others, while more focused on the here-and-now of space exploration, can find the wider context motivating and energizing.

Eniac March 20, 2016 at 18:48

About AI: Consciousness and self-awareness are pretty mushy concepts that are hard to pin down. We humans, though, have very limited self-awareness. We are “aware” of our “conscious” thoughts (a tautology, this), but most of the activity in our brain is unconscious. What is more, both conscious and unconscious activity are completely beyond our comprehension in terms of mechanism.

What will really shake things up is a much more radical form of “self-awareness”: An AI that is such a good AI software engineer that it can comprehend and improve it’s own inner workings. It does not have to be “AGI” really: All that is needed is a software system specializing in the development of AI based software systems.

tesh March 21, 2016 at 12:42

unfortunately two sufi books come to mind, both of which leave a bitter taste in the mouth:
Destination Void (Frank Herbert)
Hitchhikers guide to the galaxy (D Adams)

tesh March 21, 2016 at 15:41

sifi not sufi (obviously…)

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