VII. Pedia Sapiens: A Genesis Future on Earth and in the Heavens
C. An Earthropic Principle: Novel Evidence About a Special Planet
Josephson, Brian. Biological Observer-Participation and Wheeler’s ‘Law without Law.’. arXiv:1108.4860. Cited more in Quantum cosmology, online October 2011, the Cambridge University, Nobel laureate, physicist philosopher continues his project to recast science, and the resultant cosmos, from dead to alive, from vested mechanist reduction to openings to its fundamental biological fertility. Hard to say, difficult to carry off, but significantly, bravely, going forward with this imperative correction. Once again, John Archibald Wheeler’s self-selecting model is most apt. And as many have tried to express, nature is to be seen as deeply textual in kind, here in a semiotic way. A further clue is the fractal self-similarity of life’s emergence.
Kouvenhoven, M. B. N, et al. Planetary Systems in Star Clusters. arXiv:1609.00898. After two decades of scientific realizations of a radically different cosmos that fills itself with planetary objects of all manner of types, sizes and stellar locales, a team of astrophysicists with joint Chinese and Dutch postings add another observation of how our own sun system is uniquely special. Most stars, as also galaxies, actually tend to collect and bunch together, so that planets in these jumbled environs are not in circular orbits but “scatter and disperse” widely.
Thousands of confirmed and candidate exoplanets have been identified in recent years. Consequently, theoretical research on the formation and dynamical evolution of planetary systems has seen a boost, and the processes of planet-planet scattering, secular evolution, and interaction between planets and gas/debris disks have been well-studied. Almost all of this work has focused on the formation and evolution of isolated planetary systems, and neglect the effect of external influences, such as the gravitational interaction with neighbouring stars. Most stars, however, form in clustered environments that either quickly disperse, or evolve into open clusters. Under these conditions, young planetary systems experience frequent close encounters with other stars, at least during the first 1-10 Myr, which affects planets orbiting at any period range, as well as their debris structures. (Abstract)
Lammer, Helmet, et al. The Role of Nitrogen as a GeoBiosignature for the Detection and Characterization of Earth-like Habitats. arXiv:1904.11716. A seven member group mainly from the Austrian Academy of Sciences Space Research Institute cites that the appropriate presence of this globally atmospheric and chemical element ought to be seen as another important factor for life’s emergent evolution.
Since the Archean, nitrogen has been a major atmospheric constituent in Earth's atmosphere. It is an essential element in the building blocks of life, therefore the geobiological nitrogen cycle is a fundamental factor in the long term evolution of both Earth and Earth-like exoplanets. We discuss the development of the Earth's N2 atmosphere since the planet's formation and its relation with the geobiological cycle. Then we suggest atmospheric evolution scenarios and their possible interaction with life forms for a stagnant-lid anoxic world, a tectonically active anoxic world, and an oxidized tectonically active world. Since life forms are the most efficient means for recycling deposited nitrogen back into the atmosphere nowadays, they sustain its surface partial pressure at high levels. (Abstract excerpt)
Lineweaver, Charles and Molly Townes O’Brien. The Cosmic Context of the Millennium Development Goals: Maximum Entropy and Sustainability. Thomas Faunce, ed. Nanotechnology Toward the Sustainocene. Singapore: Pan Stanford Publishing, 2015. An Australian National University astronomer and law professor expansively situate our crucial imperative to achieve a better populace and planet within a widest temporal and spatial evolutionary locus. In this whole scenario, a global transition to organic viability would contribute to the arrow and advance of informed, personified order over disorderly dissipations.
Life forms are a subset of the organized structures in the universe known as far-from equilibrium dissipative systems (FarFEDS). FarFEDS are dissipative structures that, while maintaining their structure, convert low-entropy energy to high-entropy energy. They include galaxies, stars, convection cells, typhoons, fires, humans, and bacteria. All FarFEDS (and thus all life forms) extract free energy from the environment and turn it into waste heat faster than random processes such as diffusion would be able to do. (41-42)
Lingam, Manasvi and Abraham Loeb. Dependence of Biological Activity on the Surface Water Fraction of Planets. arXiv:1809.09118. The Harvard University, Institute for Theory and Computation postdoc and director team (search) continue their studies of extraterrestrial life by noting a critically vital feature of this habitable Earth, namely a 30% land and 70% ocean ratio maintained over some three billion years. As such multiphase exoplanet research proceeds apace, it is becoming evident that this dual division is a rarest state. The common spherical default is wholly dry, watery or gaseous. Plate tectonic movements are then seen to add a significant favorable condition (still going on in the Pacific rim of fire). A previous entry (L & L, 1804.02271) considered the effect of stellar physics on planetary life. As this section seeks to report, our home sapient Earth seems to be an increasingly special bioplanet amongst myriad vicarious candidates. This is an awesome, unexpected finding in need of much public report and notice, at a same time when nuclear nations are in headlong regression.
One of the unique features associated with the Earth is that the fraction of its surface covered by land is comparable to that spanned by its oceans and other water bodies. Here, we investigate how extraterrestrial biospheres depend on the ratio of the surficial land and water fractions. We find that worlds that are overwhelmingly dominated by landmasses or oceans are likely to have sparse biospheres. Our analysis suggests that major evolutionary events such as the buildup of O2 in the atmosphere and the emergence of technological intelligence might be relatively feasible only on a small subset of worlds with surface water fractions ranging approximately between 30% and 90%. We also discuss how our predictions can be evaluated by future observations, and the implications for the prevalence of microbial and technological species in the Universe. (Abstract)
Lingam, Manasvi and Abraham Loeb. Implications of Tides for Life on Exoplanets. arXiv:1707.04594. Harvard-Smithsonian Center for Astrophysics theorists consider this geospheric surface condition which could have a major influence on long-term habitability. Our own Earth-moon system is an optimum situation of moderate tidal flows and basins, whereof cellular life can begin its evolutionary course. However, on the many other exoworlds just being found, this stable state maybe a rare occurrence. A corollary or default phase has become known “tidal locking” whence an orbiting object enters a tandem rotation with a host star or moon, see Tidal Locking of Habitable Exoplanets by Rory Barnes herein.
As evident from the nearby examples of Proxima Centauri and TRAPPIST-1, Earth-sized planets in the habitable zone of low-mass stars are common. Here, we focus on such planetary systems and argue that their (oceanic) tides could be more prominent due to stronger tidal forces. We identify the conditions under which tides may exert a significant positive influence on biotic processes including abiogenesis, biological rhythms, nutrient upwelling and stimulating photosynthesis. We conclude our analysis with the identification of large-scale algal blooms as potential temporal biosignatures in reflectance light curves that can arise indirectly as a consequence of strong tidal forces. (Abstract)
Lingam, Manasvi and Abraham Loeb. Physical Constraints for the Evolution of Life on Exoplanets. arXiv:1810:02007. Some two weeks after a posting (1809.09118, see also 1807.08879, 1804.02271) about how plate tectonics can effect habitability, this Harvard team, funded in part by the Breakthrough Foundation, here view additional vicarious cosmic, solar, and geologic influences such as stellar coronal winds and flares, planetary magnetospheres, oceanic and atmospheric evaporations, electromagnetic radiation, relative oxygen buildup, origins of life, photosynthesis, and more in mathematic detail. These studies are then supported with some 300 references. Once again, this home Earth whereupon a sapient species is altogether able to explore, quantify and learn, seems to be an increasingly unique candidate personsphere.
Some two weeks after a posting (1809.09118, see also 1807.08879, 1804.02271) about how plate tectonics can effect habitability, this Harvard team, funded in part by the Breakthrough Foundation, here view additional vicarious cosmic, solar, and geologic influences such as stellar coronal winds and flares, planetary magnetospheres, oceanic and atmospheric evaporations, electromagnetic radiation, relative oxygen buildup, origins of life, photosynthesis, and more in mathematic detail. These studies are then supported with some 300 references. Once again, this home Earth whereupon a sapient species is altogether able to explore, quantify and learn, seems to be an increasingly unique candidate personsphere.
Livingston, John. One Cosmic Instant. Boston: Houghton Mifflin, 1973. Some 35 years ago the York University environmentalist placed earth’s increasing ecological stress, evident even then, in the long perspective of a special bioplanet whose life evolves to human technological sentience, only to place itself at terminal peril. Today it is often said that we have already overshot a global carrying capacity, that earth has a fever, temperature unknown, that its physiology can in fact perish. By this view, we have indeed reached a second singularity which requires our mindful self-selection.
Livio, Mario. How Special is the Solar System?. arXiv:1801.05061. The veteran Romanian, Israeli, American astrophysicist and author (search) posts a chapter to appear in Consolidation of Fine-Tuning, see Anthropic Principle for website. Livio also has a joint chapter with Martin Rees about the multiverse, noted herein. To wit, an array of unusual features such as a quiet, stable sun, orderly planetary orbits and spacings, and more do allude to a rare cocatenation. While early and speculative, there is something curious about our home Earth-Sun nexus, as a sentient species begins to wonder about it all.
Given the fact that Earth is so far the only place in the Milky Way galaxy known to harbor life, the question arises of whether the solar system is in any way special. To address this question, I compare the solar system to the many recently discovered exoplanetary systems. I identify two main features that appear to distinguish the solar system from the majority of other systems: (i) the lack of super-Earths, (ii) the absence of close-in planets. I examine models for the formation of super-Earths, as well as models for the evolution of asteroid belts, the rate of asteroid impacts on Earth, and of snow lines, all of which may have some implications for the emergence and evolution of life on a terrestrial planet. (Abstract)
Martin, David. Populations of Planets in Multiple Star Systems. arXiv:1802.08693. In a chapter for the Handbook of Exoplanets (September 2018), a Swiss National Science Foundation Fellow at the University of Chicago gathers latest findings that find orbital worlds in a vicinity of two or more suns with as fairly common, maybe up to half of galactic cases. The situation is seen as an exotic example of nature’s ubiquitous diversity. It is then generally surmised that such a chaotic solar and planetary arrangements are not favorable, indeed ruinous, for long life term habitability.
Mathews, Freya. Moral Ambiguities in the Politics of Climate Change. Nanda, Ved, ed.. Climate Change and Environmental Ethics. New Brunswick, NJ: Transaction Publishers, 2011. Two decades after her visionary The Ecological Self work about individual and cosmic self-realization (search), the Australian ecophilosopher continues to meld “anthropocentric and biocentric” options in a viable, creative synthesis. Along with the quotes, she advises a “bio-synergy,” a “relational inter-functionality” of persons and planet, little self and Big self, as each engaged in a deep process of psychic individuation.
I would like to propose two ways – both holistic, but differently so – in which “nature” under its global aspect might be conceived. The first such way in which nature might be conceived is as a self-realizing or autopoetic system, defined not in terms of the elements that contingently constitute it, but in terms of its ends as an entity in its own right, which is to say, in terms of its status as an end-for-itself, and its disposition to navigate circumstances in such a way as to preserve its own identity as a living system through time and change. (48)
McIntyre, Sarah, et al. Planetary Magnetism as a Parameter in Exoplanet Habitability. arXiv:1903.03123. Australian National University astrophysics including Charles Lineweaver proceed to add another physical, geologic factor which could influence whether a globular, orbital object might harbor living systems and an evolutionary intelligence. As the abstract says, a certain range of values are required to maintain conducive watery and airy conditions.
Evidence from the solar system suggests that, unlike Venus and Mars, the presence of a strong magnetic dipole moment on Earth has helped maintain liquid water on its surface. Therefore, planetary magnetism could have a significant effect on the long-term maintenance of atmosphere and liquid water on rocky exoplanets. We use Olson and Christensen's (2006) model to estimate magnetic dipole moments of rocky exoplanets with radii Rp ≤ 1.23 R⊕. Even when modelling maximum magnetic dipole moments, only Kepler-186 f has a magnetic dipole moment larger than the Earth's, while approximately half of rocky exoplanets detected in the circumstellar habitable zone have a negligible magnetic dipole moment. This suggests that planetary magnetism is an important factor when prioritizing observations of potentially habitable planets. (Abstract)