Greg Matloff: Conscious Stars Revisited

by Paul Gilster | Sep 18, 2015 | Culture and Society | 150 comments

It’s no exaggeration to say that without Greg Matloff, there would have been no Centauri Dreams. After reading his The Starflight Handbook (Wiley, 1989) and returning to it for years, I began working on my own volume in 2001. Research for that book would reveal Matloff’s numerous contributions in the journals, especially on solar sail technologies, where he illustrated early on the methods and materials needed for interstellar applications. A professor of physics at New York City College of Technology (CUNY) as well as Hayden Associate at the American Museum of Natural History, Dr. Matloff is the author of, among others, Deep Space Probes (Springer, 2005) and Solar Sails: A Novel Approach to Interplanetary Travel (with Les Johnson and Giovanni Vulpetti; Copernicus, 2008). His latest, Starlight, Starbright, is now available from Curtis Press, treating the controversial subject of today’s essay.

by Greg Matloff

Introduction: Motivations

As any web search will reveal, most of my research contributions have been in the fields of in-space propulsion, SETI, Earth-protection from asteroid impacts, planetary atmospheres, extra-solar planet detection and spacecraft navigation. Since I have consulted for NASA on solar-sail applications, I have trained myself to err on the side of conservatism. However, a true scientist cannot ignore observational data. He or she must base hypothesis and theories upon such results, not upon previous experience, ideology and dogma.

Image: Gregory Matloff (left) being inducted into the International Academy of Astronautics by JPL’s Ed Stone.

Until 2011, I never expected that I might contribute to the fascinating debate regarding the origin and nature of consciousness. On one side are the epiphenomenonalists, who believe that consciousness is a mere byproduct of bio-chemical activity in the complex brains of higher organisms. On the other side are the panpsychists, who believe that a universal field responsible for consciousness, sometimes referred to as “proto-consciousness,” reacts with matter to produce conscious activity at all levels. The philosophical arguments were fascinating, but to me as a scientist they were a bit disappointing. There seemed to be no way of elevating the argument from the realm of deductive philosophy to the realm of observational/experimental science.

But in 2011, as documented in my June 12, 2012 contribution to this blog – Star Consciousness: An Alternative to Dark Matter – I learned (much to my surprise) that it may be possible now to construct simple models of universal consciousness and test them against observational evidence.

I was primed for this work by several factors. First, an early mentor of mine and a coauthor of several astronautics papers, was the late Evan Harris Walker. With expertise in plasma and quantum physics, Harris (as his friends called him) was a pioneer in the infant field of quantum consciousness. Although I am far from an expert in quantum mechanics, I was fascinated by Harris’ attempt to explain consciousness by the quantum tunneling of wave functions through potential wells created by the inter-synaptic spacing in mammal brains [1].

After the success of The Starflight Handbook and other contributions to interstellar travel studies, I was asked by Apollo 11 astronaut Buzz Aldrin in the early 1990’s to join the team of scientific consultants for a science-fiction novel he was co-authoring with John Barnes [2]. For plot purposes, Buzz required the stable, long-term existence of a Jupiter-like planet at a 1 Astronomical Unit (AU) distance from a Sun-like star. When he asked me to check the possibility of such a planet, I was initially very pessimistic. When I told Buzz that most exoplanet experts believed that the Hydrogen-Helium atmosphere of such a planet would likely evaporate quickly (in cosmic terms), he asked me to check this assumption. I located an appropriate equation in a space science handbook and calculated the estimated lifetime of the giant planet’s atmosphere. I was surprised and Buzz was gratified to learn that the lifetime of the Jovian’s atmosphere at 1 AU would be billions of years. At that point in my career, I was an adjunct professor and consultant. Since I was unable to locate a derivation for the subject equation, I elected not to challenge scientific orthodoxy and attempt to publish these results in a scientific journal. After the discovery of “hot Jupiters” circling Sunlike stars a few years later, I became credited (by Paul Gilster and others) with predicting the existence of hot Jupiters in a science-fiction novel, but not in a peer-reviewed journal. I vowed to never repeat this mistake again and hold back data, if my results challenged established paradigms.

The third influence pointing me in the direction of conscious stars was an undergraduate, liberal arts student at New York City College of Technology. Between the time I became a tenure-track professor in 2003 and my retirement from full-time teaching in 2011, I organized and coordinated the astronomy program at New York City College of Technology (NYCCT). In the first term of the NYCCT astronomy sequence, students learn about astronomical history, aspects of classical and modern physics and solar-system astronomy. In the second term, they investigate the astrophysics of the Sun, stars, and galaxies, cosmology, and the prospects for extraterrestrial life. In one Astronomy 2 section, I was lecturing about dark matter. The existence of this mysterious substance has been invited to explain anomalous stellar motions. When a liberal arts undergraduate interrupted the lecture, I learned that he doubted dark matter’s existence. His supposition was that physics is at an analogous stage to the situation in 1900. A major shift in physical paradigms may be necessary to explain the many anomalies (including dark matter) building up in observational astrophysics.

In 2011, it all came together. Kelvin Long, who edits the Journal of the British Interplanetary Society (JBIS), invited me to participate in a one-day symposium at the London headquarters of the BIS to celebrate the work of Olaf Stapledon, a British science-fiction author and philosopher who has greatly influenced astronomical and astronautical thought. In his 1937 masterwork Star Maker, Stapledon predicted nuclear energy, nuclear war, interstellar travel, space habitats and rearrangement of solar systems by intelligent extraterrestrials. Because I usually author papers on these topics and have often cited Star Maker, I elected to avoid astrotechnology in my contribution to this BIS symposium and instead concentrate on a core aspect of Stapledon’s philosophy: that the stars and indeed the entire universe are in some sense conscious.

A Toy Model of Stellar Consciousness and Astrophysical Evidence

Many people have written about consciousness. Since there is no agreed upon definition of this quality, I decided to investigate a symptom of stellar consciousness. This is Stapleton’s supposition that a fraction of stellar motions around the centers of their galaxies is volitional. According to Stapledon, stars obey the canons of a cosmic dance as they travel through space. Many researchers consider the seat of consciousness in humans and other lifeforms to be neurons or tubules [1,3,4]. I have little knowledge regarding the intimate details of the stellar interior. But I am pretty sure that neurons and tubules do not exist within stars. However, most cooler stars, including the Sun, do have simple molecules in their upper layers.

Contrary to what many of us learned in high school chemistry, the Van der Waals forces that hold the atoms in molecules together are not purely electromagnetic. Some of this attraction is due to the so-called Casimir Effect [5]. Vacuum is not truly empty. Instead, in tiny intervals of space and time, there are enormous fluctuations of energy and matter. Generally, positive and negative energies in these fluctuations exactly balance. But in the opinion of most cosmologists, the Big Bang was a stabilized vacuum fluctuation. All the matter, energy, space and time in the universe inflated from a tiny volume of dynamic vacuum during this event.

An echo of this most creative event in the universe’s history occurs in every molecule. Not all vacuum fluctuations can fit between adjacent molecules. A fraction of the Van der Waals force holding molecules together is produced by the pressure of these vacuum fluctuations.

With astrophysicist Bernard Haisch [6], I assumed that a proto-consciousness field operates through vacuum fluctuations or is identical to these fluctuations. I developed a very simple “toy model” in which this field produces a form of primitive consciousness by its interaction with molecular matter in the Casimir Effect (Fig. 1).

Fig. 1. A “Toy Model” of Proto-Panpsychism.

But models, no matter how simple or complex, are useful in physics only if they can be validated through experiment or observation. So I conducted a Google search for “Star Kinematics Anomaly and Discontinuity”.

Contrary to my expectation, what appeared on my screen was amazing. There was a Soviet-era Russian astronomer named Pavel Parenago (1906-1960). In addition to his astronomical contributions, Dr. Parenago was a very clever man. Unlike many of his colleagues, he avoided an extended vacation in a very cold place by dedicating a monograph to the most highly evolved human of all times – Joseph Stalin!

The anomaly named after Parenago, which is referred to as “Parenago’s Discontinuity”—is his observation that cool, low-mass stars in our galactic vicinity (such as the Sun) move around the center of the Milky Way galaxy a bit faster than their hotter, higher-mass sisters.

I used two sources to quantify Parenago’s Discontinuity for nearby main sequence stars. One was a chapter in Allen’s Astrophysical Quantities, a standard reference in astrophysics [7]. The second was a compilation of observations of 5610 main sequence stars using the European Space Agency (ESA) Hipparcos space observatory out to a distance of ~260 light years [8]. Figure 2, a graph presenting this data, is also included in my June 12, 2012 contribution to this blog and the JBIS paper based on my contribution to the BIS Stapledon symposium [9].

In Fig. 2, star motion in the direction of galactic rotation is plotted against star (B-V) color index, which is a measure of the difference between star radiant output in the blue range of the spectrum and the center of the human eye’s visual sensitivity. Hot, blue, massive stars have low and negative (B-V) color indices. From Table 19.1 of Ref. 7, G spectral class main sequence stars such as the Sun have (B-V) color indices in the range of about 0.6-0.7.

Fig 2: Solar Motion in Direction of Galactic Rotation (V) for Main Sequence Stars vs. Star Color Index (B-V). Diamond Data Points are from Gilmore & Zelik. Square. Data Points are from Binney et al.

Note in Fig. 2 that cooler stars to the right of the discontinuity move as much as ~20 kilometers per second faster than their hotter sisters around the center of the galaxy. As discussed in the June 12, 2012 contribution to this blog and in Ref. 9, Parenago’s Discontinuity occurs near the point where stable molecules begin to appear in stellar spectra.

Recent Work and Consideration of Alternative Hypotheses

Science is essentially a testing ground of alternative hypotheses to explain observational and experimental data. Since data points to at least the local reality of Parenago’s Discontinuity, some astrophysicists have developed rival explanations to Volitional Stars.

One possibility is stellar boil-off from local stellar nurseries. Perhaps this results in faster motions for cooler, low mass stars. But this process should result in a greater velocity dispersion in low mass stars, not a higher velocity of revolution around the galaxy’s center. Also, stellar nurseries typically live for tens of millions of years [10]. Why is there no discontinuity in the motions of short-lived O and B stars?

If Parenago’s Discontinuity is a local phenomena extending out a few hundred light years from the Sun, at least one other alternative explanation is possible. This is the Spiral Arms Density Waves concept [11]. The matter density of the interstellar medium is not uniform. Although the typical density of ions and neutral atoms in the Sun’s vicinity (the so-called Intercloud Medium) is less than 0.1 per cubic centimeter, matter density in the cooler, mostly neutral diffuse nebula that operate as stellar nurseries in the spiral arms of our galaxy is orders of magnitude greater. If a dense diffuse nebula passed through our galactic vicinity in the distant past, low-mass, cool, redder stars might be dragged along faster by the dense cloud than hot, blue, more massive stars.

There are at least two ways to check the validity of the Spiral Arms Density Waves hypothesis. One is to investigate the typical size of diffuse nebula in the Milky Way galaxy. The second is to check observational consequences of this hypothesis.

In a recent book, I reviewed the sizes of diffuse nebula in Messier’s compilation [12]. As part of a recent research paper, I performed a similar review of the more comprehensive Herschel catalog and an on-line listing of New General Catalog (NGC) deep-sky objects [13]. These results are summarized in Fig. 3.

Fig 3: Fraction of Galactic Bright Diffuse Nebulae with Diameters > D Light Years from Messier (Blue), Herschel (Green) and Atlas of the Universe—NGC (Yellow) Compilations.

Note in Fig. 3 that, in all three compilations of deep-sky objects, diffuse nebulae with diameters greater than a few hundred light years are rare. Since the Hipparcos main sequence dataset used in Ref. 8 includes stars in a ~500 light year diameter sphere, Fig. 3 does not support the Spiral Arms Density Wave hypothesis.

But there is worse news for this hypothesis, also derived from Hipparcos data. Giant stars are considerably brighter than their less evolved counterparts on the main sequence and
are consequently visible over greater distances. Richard Branham, an astrophysicist based in Argentina, has analyzed the kinematics of thousands of giant stars in the Hipparcos data set [14]. His conclusion that Parenago’s Discontinuity is present in these results is demonstrated in Fig. 4.

Fig 4: Giant Star Motion (V) in Direction of Sun’s Galactic Revolution. The reduction of Branham’s data to produce Fig. 4 is discussed in Chap. 23 of Ref. 12.

Note that Fig. 4 is not as neat as the corresponding results for main sequence stars in Fig. 2. This may be due to uncertainty in the > 1,000 light year distance estimates for many of the stars in Branham’s Sample.

An interpretation of the above results is that a local explanation for Parenago’s Discontinuity is unlikely. Existing galactic diffuse nebula are simply too small (and widely separated, as discussed in Ref. 12) to produce a stellar kinematics anomaly over a radius greater than 1,000 light years.

However, although the existing data does not support Spiral Arms Density Waves, the sample of stars, which numbers in the thousands, is not large enough to rule out this and other local explanations for Parenago’s Discontinuity. After all, the Milky Way galaxy contains more than a hundred billion stars.

Within the next few years, astrophysicists should know conclusively whether Parenago’s Discontinuity is a local or galactic phenomenon. In December 2013, the European Space Agency (ESA) launched Gaia as a more capable successor to the Hipparcos space observatory. While Hippasrcos accurately determined the distance and motions of perhaps 100,000 stars,
Gaia should gather similar data over the next few years for about a billion stars in the Milky Way galaxy. Gaia, its mission and capabilities are discussed in more detail in Ref. 12.

Fig 5: The European Space Agency’s Gaia Space Observatory (Courtesy ESA).

But even before the data from Gaia is analyzed and released, astronomers using different equipment have gathered preliminary data that may lead to the falsification of the Spiral Arms Density Waves hypothesis. Note in Fig. 6 the structure of M51, a typical nearby spiral galaxy not dissimilar from the Milky Way. The revolution of this galaxy is in the counterclockwise direction, from our point of view. Hundreds of millions of years are required for one
complete revolution [15].

A team of astronomers have carefully analyzed the light received from the leading and lagging edges of spiral arms of twelve nearby spiral galaxies. For the Spiral Arms Density Waves Hypothesis to be correct, differences should be observable between these two locations. Sadly for Density Waves (and happily for Volitional Stars), such an effect was not noticed.

Fig 6: The Whirlpool Galaxy M51 (courtesy NASA).

Since the universe contains ~100 billion spiral galaxies, this result is not conclusive. Using new telescopes, about 300 spirals should be observed to statistically rule out Density Waves. Density Waves is apparently limping, but it cannot yet be completely ruled out.

If observations from Gaia indicate that Parenago’s Discontinuity is a galactic phenomenon rather than a local phenomenon, some astrophysicists will attempt to develop explanations that are alternatives to Volitional Stars. As discussed in Ref. 13, this will be challenging. The only reasonable galaxy-wide explanation might be a collision between the Milky Way galaxy and another large galaxy in the distant past. While such a collision might have produced a galaxy-wide “starburst” episode of rapid star formation, simulations indicate that the ultimate result of such galaxy smash-ups is a giant elliptical galaxy, not a spiral such as the Milky Way.

Volitional Star Kinematics

In my June 12, 2012 contribution to this blog, I considered methods that a volitional star could use to adjust its galactic velocity. One possibility was stellar jets.

Many infant stars eject high-velocity matter streams (Fig. 7). Surprisingly, some of them are unipolar or unidirectional, ejecting more material in one direction than others [16]. In April 2015, Paul Gilster e-mailed a link indicating that solar winds from mature stars like the Sun
enter interstellar space in a complex system of jets [17]. The complexity of these jets is at least partially due to solar galactic motion and the interaction between the solar and galactic magnetic fields. Uni-directional matter jets from infant and young stars are discussed in greater detail in Chap. 15 of Ref. 12.

Fig 7: A Jet of High-Velocity Material Ejected From an Infant Star (courtesy NASA).

If Gaia observations reveal that Parenago’s Discontinuity is a galaxy-wide phenomenon, attention might turn to these unidirectional stellar jets. Are they generally aligned to accelerate molecule-bearing stars in the direction of their galactic motion? Since star galactic revolution velocities generally increase with distance from the galactic center, do jet velocities increase as well?

Although unidirectional material jets from infant and mature stars is one method that a volitional star could use, there is another possibility. This is the admittedly very controversial possibility of a weak psychokinetic (PK) force. Much has been written about the investigation of PK and related paranormal phenomena funded by US intelligence agencies.

As I have described in my earlier treatments of this subject, this is the only scientific controversy that I am privileged to know participants on opposing sides. On one hand are the physicists who claim that Uri Geller, the alleged psychic who scored best on their screening tests, could not possibly have cheated on these tests. On the other hand, I met a retired Time-Warner editor at a cocktail party years ago who demonstrated that Geller’s signature fork bending could be duplicated as a magic trick, and who also claimed to have enlisted a magician The Amazing Randi, to further investigate Geller.

Many web sources conclude that Geller is indeed a trained magician. When my friend Dr. Eric Davis of the Institute for Advanced Studies at Austin (Texas) mentioned (while reviewing a draft copy of Ref. 12) that there is no confirmation of Geller actually having attended a magician’s college, I decided to check what I consider the best reference available on the Geller-Randi controversy. I carefully checked a book by MIT physics professor David Kaiser on this topic and learned that Dr. Davis is apparently correct [18].

Eric Davis also sent me an electronic copy of a report he authored for the US Air Force in 2005. Many countries other than the US have investigated PK and related phenomena in studies funded by government agencies. Some of the results are positive and have reportedly been replicated [19, 20].

As discussed in Refs. 9 and 12 and my June 12, 2012 submission to this blog, a PK force required to accelerate a Sun-like star by 20 km/s during a ~1-billion-year time interval is many orders of magnitude less than that required to bend a kitchen utensil. Perhaps it is time for experimental physicists to put the Geller-Randi controversy aside and perform a new set of carefully controlled experiments to test the existence or non-existence of a weak PK effect.

One possibility discussed by others is to include professional magicians on the experiment design team. Another possibility, raised by a responder to my June 12, 2012 contribution to this blog, is to perform PK tests on the interaction between human subjects and an Einstein-Bose condensate. As further discussed in Ref. 12, an Einstein-Bose condensate is a macroscopic state of matter in which all of the particles share the same quantum state. A human subject might be instructed to see if he or she could “will” the condensate to climb the enclosure wall repeatedly to the same level. This would test not only the validity of PK but the assumption that consciousness is related to quantum phenomena.

Conclusions: A Learning Experience

Since 2011, I have spent a large fraction of my creative time investigating whether the Volitional Star hypothesis can be considered scientific. As reviewed in Ref. 12, it is certainly a venerable concept. Shamans, astrologers, philosophers, mystery-cult members, poets, and fiction authors have considered this possibility for millennia.

It is also interesting that at least a few scientists have walked this path before me. Although the concepts of stellar or universal consciousness are certainly not in the scientific mainstream at present, scientific speculation along these lines is becoming more respectable.

One creative group that apparently welcomes these concepts is fine artists. The chapter frontispiece art in Ref. 12 created by C Bangs has been presented in several artistic forums, including the Arts Program at the 9th IAA Symposium on the Future of Space Exploration, which was held in Turin, Italy in July 2015. A version of one of these images is presented as Fig. 8. Modifications of 18 of these images on 11″ X 14″ panels painted on both sides in the form of an accordion book are on display at the Manhattan gallery that C Bangs is affiliated with: Central Booking Art Space, 21 Ludlow Street.

Fig 8: Modified Version of C Bangs Chapter frontispiece from Starlight, Starbright.

Recently, with my assistance, C prepared an Artist’s Book entitled Star Bright?. In July 2015, Star Bright? was collected by the Prints and Illustrated Books division of the Museum of Modern Art in Manhattan.

It is of course very premature to claim that the work presented here has proven the case for volitional stars. The toy model of proto-panpsychism is certainly too simple to have much traction in the theoretical world. But it is not impossible that this work might move panpsychism from the realm of deductive philosophy to the realm of observational astrophysics.

References

1. E. H. Walker, “The Nature of Consciousness,” Mathematical Biosciences, 7, 131-178 (1970). Also see E. H. Walker, The Physics of Consciousness, Perseus, Cambridge, MA (2000).

2. B. Aldrin and J. Barnes, Encounter with Tiber, Warner, NY (1996).

3. L. Margulis, “The Conscious Cell”, Annals of the New York Academy of Sciences, 929, 55-70 (2001).

4. S. Hameroff, “Consciousness, the Brain, and Spacetime Geometry”, Annals of the New York Academy of Sciences, 929, 74-104 (2001) and R. Penrose, “Consciousness, the Brain, and Spacetime Geometry: An Addendum”, Annals of the New York Academy of Sciences, 929, 105-110 (2001).

5. H. Genz, Nothingness: The Science of Empty Space, Perseus, Cambridge, MA (1999).

6. B. Haisch, The God Theory, Weiser, San Francisco, CA (2006).

7. G. F. Gilmore and M. Zelik, “Star Populations and the Solar Neighborhood,” in Allen’s Astrophysical Quantities, 4th ed. A. N. Cox ed., Springer-Verlag, NY (2000), Chap. 19.

8. J. J. Binney, W. Dehnen, N. Houk, C. A. Murray, and M. J. Preston, “Kinematics of Main Sequence Stars from Hipparcos Data,” Proceedings of the ESA Symposium Hipparcos Venice
’97, SP-402, Venice, Italy, 13-15 May 1997, pp. 473-477 (July, 1997).

9. G. L. Matloff, “Olaf Stapledon and Conscious Stars: Philosophy or Science?”, JBIS, 65, 5-6 (2012).

10. E. Chaisson and S. McMillan, Astronomy Today, 6th ed., Pearson-Addison/Wesley, San Francisco, CA (2008), Chap. 19.

11. R. S. DeSimone, X. Wu, and S. Tremaine, “The Stellar Velocity Distribution of the Stellar Neighborhood”, Monthly Notices of the Royal Astronomical Society, 350, 627-643 (2004).

12. G. L. Matloff and C Bangs, Starlight, Starbright: Are Stars Conscious?, Curtis Press, UK (2015).

13. G. L. Matloff, “The Non-Locality of Parenago’s Discontinuity and Universal Self Organization”, IAA-FSE-15-06-03. Presented at 9th IAA Symposium on the Future of Space Exploration, Turin, Italy, July 7-9, 2015. Published in Conference Proceedings.

14. R. L. Branham, “The Kinematics and Velocity Ellipsoid of GIII Stars,” Revisita Mexicana de Astronomia y Astrofisica, 47, 197-209 (2011).

15. K. Foyle, H.-W. Rix, C. Dobbs, A. Leroy, and F. Walter, “Observational Evidence Against Long-Lived Spiral Arms in Galaxies,” Astrophysical Journal, 735 (2), Article ID = 101 (2011), arXiv: 1105.5141 [astro-ph.CO].

16. F. Namouni, “On the Flaring of Jet-Sustaining Accretion Disks”, Astrophysical Journal, 659, 1505-1510 (2007).

17. I. O’Neill, “Sun May Blast Two Jets of Plasma into Interstellar Space”, news.discovery.com, (March 4, 2015). Also see “A New View of the Solar System: Astrophysical Jets Driven by the Sun”, bu.edu (February 19, 2015).

18. D. Kaiser, How the Hippies Saved Physics, Norton, NY (2011).

19. E. W. Davis, “Teleportation: Mind and Intelligence”, Report to the US Air Force Future Technology Branch, Future Concepts and Transformation Division Workshop, Mitre Corporation, McLean VA (Oct. 21, 2005).

20. E. W. Davis, “Teleportation Physics Study,” Final Report AFRL-PR-ED-TR-2003-0034, Air Force Research Laboratory, Air Force Materiel Command, Edwards AFB, CA (2004): https://www.fas.org/sgp/eprint/teleport.pdf

StarSearch: Our Hunt for a New Home World

by Paul Gilster | Mar 14, 2016 | Culture and Society | 91 comments

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

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.

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.

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.

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.

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.

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.

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.