![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
|
![]() |
![]() |
||||||||||
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
|
III. Ecosmos: A Revolutionary Fertile, Habitable, Solar-Bioplanet Incubator LifescapeI. Our EarthMost Occasion: A Rarest Confluence of Favorable Features and Close Calls Forgan, Duncan, et al. Evaluating Galactic Habitability Using High-Resolution Cosmological Simulations of Galaxy Formation. International Journal of Astrobiology. Online January, 2016. Astroscientists Forgan, with Pratika Dayal, Charles Cockell, and Noam Libeskind, proceed as Earthlings to seek out effective ways to estimate the relative kinds, areas, and phases of galaxies which might be favorable for living systems to form and evolve. Forget, Francois. On the Probability of Habitable Planets. International Journal of Astrobiology. 12/3, 2013. With the rush of Kepler satellite discoveries of a Milky Way and universe filled with solar systems and orbital objects of every kind, the prevalence, or absence, of earth-analog bioworlds has become a prime issue. An Institute Pierre Simon Laplace, Universite Paris, astrophysicist here provides a succinct technical survey. Four classes of conducive worlds are cited: Planets like this with suitable water, atmosphere, and stabilities; Earth-like but unable to hold aqueous seas; Worlds with too much water and/or geothermal activity; and Ice covered, frozen globes. A suggestive allusion as made by Paul Davies, John Gribbin and others, is that in some real way our minute, self-regulating orb just flickering into knowing consciousness may be of immense significance after all. In the past 15 years, astronomers have revealed that a significant fraction of the stars should harbor planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for the emergence of a life able to modify its environment and evolve. A first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. This have been studied with global mean 1D models which has defined the “classical habitable zone”, the range of orbital distances within which worlds can maintain liquid water on their surfaces. A new generation of 3D climate models based on universal equations and tested on bodies in the solar system is now available to explore with accuracy climate regimes that could locally allow liquid water. A second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seems to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth’s case may be special and uncommon. (Abstract)
Frank, Adam.
Light of the Stars: Alien Worlds and the Fate of the Earth.
New York: Norton,
2019.
The University of Rochester astrophysicist and author (search UR) provides a latest survey of the 2ist century revolutionary witness of an innately planet and solar system making cosmos, which begets living systems and a global sapience able to learn this. The unique work is an insider’s view of profligate biospheres and maybe noospheres, citing Vernadsky, Teilhard, Lovelock and Lynn Margulis, which infer a growing sense of an inherent astrobiology. But these findings lead us to realize that our Anthropocene moment is due to many rare, favorable twists and turns along the way. From this perspective, civilizations become just another thing the Universe does, like solar flares or comets. We can use what the stars have laid out before us in our astrobiological studies to explore how any civilization on any planet can – or, in the worst case, cannot – evolve together. The advantages of this astrobiological perspective can be gained even if no other civilization ever existed. Thinking about hypothetical exo-civilizations is valuable in dealing with the challenge of the Anthropocene because it reaches us to “think like a planet.” It teaches us to frame our pathways to a long-term project of civilization in terms of the coevolution between life and the Earth. (15) Frank, Adam and Woodruff Sullivan. A New Empirical Constraint on the Prevalence of Technological Species in the Universe. arXiv:1510.08837. The University of Rochester and University of Washington astronomers update the Drake equation (search Vakoch) by way of the latest rush of satellite exoplanet findings to boost chances that our prodigious planet is not alone. See also A Population-Based Habitable Zone Perspective by Andras Zsom at arXiv:1510.06885. In this paper we address the cosmic frequency of technological species. Recent advances in exoplanet studies provide strong constraints on all astrophysical terms in the Drake Equation. Using these and modifying the form and intent of the Drake equation we show that we can set a firm lower bound on the probability that one or more additional technological species have evolved anywhere and at any time in the history of the observable Universe. We find that as long as the probability that a habitable zone planet develops a technological species is larger than ~10−24, then humanity is not the only time technological intelligence has evolved. This constraint has important scientific and philosophical consequences. (Abstract) Frank, Adam and Woodruff Sullivan. Sustainability and the Astrobiological Perspective: Framing Human Futures in a Planetary Context. arXiv:1310.3851. University of Rochester and University of Washington astrophysicists embellish the vista proposed by Arnould, Baum, and Naganuma herein that it well serves to situate our precious Earth in its fertile galactic milieu. Circa 2013, a prominent addition is the discovery of myriad extrasolar planets and widening solar habitable zones. In our Anthropocene era, only a cosmic perspective can provide both the ecosphere systems purview, and the import of an intelligent, healthy bioworld to the greater creation. We explore how questions related to developing a sustainable human civilization can be cast in terms of astrobiology. In particular we show how ongoing astrobiological studies of the coupled relationship between life, planets and their co-evolution can inform new perspectives and direct new studies in sustainability science. Using the Drake Equation as a vehicle to explore the gamut of astrobiology, we focus on its most import factor for sustainability: the mean lifetime Gardner, Andy and Joseph Conlon. Cosmological Natural Selection and the Purpose of the Universe. Complexity. Online May, 2013. To ponder, isn’t it fantastic that we brave creatures upon a conducive mote can yet, suddenly, collaboratively, expand our imaginations to roam the celestial reaches to ask whatever, whom are we, and maybe touch why? As the quotes convey, an Oxford University zoologist and a biophysicist consider, from their fields, some evolutionary reasons in support Lee Smolin’s (search 1999) title CNS theory. It is written in a usual arcane, abstract style, but offers a perceptive inkling and promise of an intended involvement of learned human volition and co-creativity of a truly universal significance. The cosmological natural selection (CNS) hypothesis holds that the fundamental constants of nature have been fine-tuned by an evolutionary process in which universes produce daughter universes via the formation of black holes. Here, we formulate the CNS hypothesis using standard mathematical tools of evolutionary biology. Specifically, we capture the dynamics of CNS using Price’s equation, and we capture the adaptive purpose of the universe using an optimization program. We establish mathematical correspondences between the dynamics and optimization formalisms, confirming that CNS acts according to a formal design objective, with successive generations of universes appearing designed to produce black holes. (Abstract) Georgakarakos, Nikolaos, et al. Giant Planets: Good Neighbors for Habitable Worlds?. arXiv:1804.02183. NYU Abu Dhabi and CalTech JPL astrophysicists add to growing perceptions that as large gaseous worlds vicariously course through solar systems, sometimes inward and back, they have a major impact upon their relative, long-term habitability by Earth-size bioworlds. See also the Astronomy article by Jesse Emspak herein for another view. The presence of giant planets influences potentially habitable worlds in numerous ways. Massive celestial neighbors can facilitate the formation of planetary cores and modify the influx of asteroids and comets towards Earth-analogs later on. Furthermore, giant planets can indirectly change the climate of terrestrial worlds by gravitationally altering their orbits. Investigating 147 well characterized exoplanetary systems known to date that host a main sequence star and a giant planet we show that the presence of 'giant neighbors' can reduce a terrestrial planet's chances to remain habitable, even if both planets have stable orbits.. (Abstract excerpt)
Gribbin, John.
Alone in the Milky Way.
Scientific American.
September,
2018.
In a topical issue on The Science of Being Human, the veteran British science writer and author of the Alone in the Universe (2011) presents a succinct update with the same message as this new section. The case for extraterrestrial civilizations has long been based on the vast, statistical estimate of a 100 billion stars in a galaxy. Into the 21st century, it became known that solar systems with life-bearing orbital bodies are the common rule. But a wealth of astronomic findings about variable suns, radiation flows, planetary forms, motions, locales, chemistries, surfaces, atmospheres, meteors, moons, and more, has given rise to an unexpected realization. Our worldwide technological society able to learn this may be the result of a rarest cosmic and evolutionary concatenation of many critical steps. Here we read of Earth’s good position within a galactic habitable zone, favorable levels of metallic elements, many fortuitous timings, how early life passed dire tests, the chancy success of Homo sapiens, and more. If of a mind to ask and see, an awesome discovery of ultimate import appears in our midst. And akin to Michael Tomasello in this issue, Gribbin closes by saying that we peoples ought to peaceably and strive for a sustainable futurity. Gribbin, John. Alone in the Universe: Why Our Planet is Unique. Hoboken, NJ: Wiley, 2011. The British science writer is amazed that with a prolific chancery of swirling galaxies, stellar chaos, askew orbits, hot Jupiters, metallicities, wandering continental plates, cometary impacts, a funny sun, toxic atmospheres, along with life’s episodic, contingent evolution, rife with extinctions, and more, it’s a wonder we inquisitive earthlings are here at all. So, once more, by this train, it is concluded We are It, and ought to decisively avail our cosmic lottery winnings to save the world and green the galaxy. And that chain (of coincidences) has so many weak links that it may mean that, for all the proliferation of stars and planets in the Universe, as an intelligent species we may be unique. (xiii) Whether or not you see the hand of God in any of this, it would mean that we are the most technologically advanced civilization in the Universe, and the only witnesses with an understanding of the origin and nature of the Universe itself. If humankind and Gaia can survive the present crises, the whole of the Milky way may become our home. If not, the death of Gaia may be an event of literally universal significance. (xv) Hall, Shannon. Summer Solstice Mystery: Does the Earth’s Tilt Hold the Secret to Life? New York Times. June 21, 2018. With this timely article, one more special feature of our conducive bioplanet comes to scientific and public notice. Earth’s axial tilt or obliquity of 23.5 degree which gifts seasonal variations is well within a 10 to 40 degree range seen as necessary. Life’s biochemistry and developmental evolution to literate intelligence requires a steady, benign climate that does not lock into hot, gaseous or cold, frozen states. Bioastronomers Rene Heller, Rory Barnes, David Ferreira and others comment, along with citations such as Climate at High-Obliquity in Icarus (243/236, 2014) and Exo-Milankovitch Cycles II: Climates of G-dwarf Planets at arXiv:1805.00283. For more see Statistical Trends in the Obliquity Distribution of Exoplanet Systems at arXiv:1805.03654. Many exoworlds, and also their sunny stars, wobble but at lower or higher deleterious angles, which often change over time. Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term is named for Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypothesized that variations in eccentricity, axial tilt, and precession of the Earth's orbit resulted in cyclical variation in the solar radiation reaching the Earth, and that this orbital forcing strongly influenced climatic patterns on Earth. (Wikipedia) Hall, Shannon. The Recipe for Other Earths. Nature. 552/20, 2017. A science writer reports upon efforts by geologists to understand our world make up so as to better evaluate whether exoplanet conditions might aid or inhibit a relative habitability. But Earth has a lot more going for it than its size, mass and favourable orbit, says Cayman Unterborn (search), an exogeologist at Arizona State University in Tempe. Its churning molten core, for example, creates and sustains a magnetic field that shields the planet’s fragile atmosphere from the solar wind. And the motion of tectonic plates helps regulate global temperatures, by cycling carbon dioxide between rocks and the atmosphere. (21) Hanlon, Michael. Save the Universe. Aeon Magazine. April, 2015. On this popular online salon, a British science journalist opens with a subtitle sentence: It is only a matter of time before our Universe goes black, cold and dies. Must this be the end of the road for life? Based on the latest scientific findings, since our precious Earthkind could well be the only phenomenal people and planet ever able to contravene and co-create, a future Save the Universe Project is proposed. The posting goes on to entertain mundane issues such as intentionally slowing down cosmic expansion within its aim to broach the very idea, possibility, vista, and challenge. The Universe will end, not with a bang, but with a whimper, maybe 10 googol years from now. That is, if no one tries to do anything about it. So, what can be done? Should life surrender to its sad, entropic fate, or should we (for ‘we’ are the only entities we know of who might be able to make a difference) at least begin to think about postponing – perhaps indefinitely – the death of the only home we have? (3) The project is not really about saving the Universe, but about saving the life within it, life without which, after all, the cosmos is just gas and rocks and vacuum. It might prove that the ultimate answer to the problem of life, the universe and everything is not, as Douglas Adams joked, 42, but simply finding a way to keep the show on the road forever. (5)
Previous 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 Next [More Pages]
|
![]() |
|||||||||||||||||||||||||||||||||||||||||||||
HOME |
TABLE OF CONTENTS |
Introduction |
GENESIS VISION |
LEARNING PLANET |
ORGANIC UNIVERSE |