Recent Additions: New and Updated Entries in the Past 60 Days
Displaying entries 91 through 94 of 94 found.
Future > Self-Selection
The Earth’s Shell has Cracked, and We’re Drifting on the Pieces.
New York Times.
The popular science writer draws upon a Royal Society meeting about plate tectonics and Philosophical Transactions A issue from it (see Robert Stern herein for more) about how our home planet has been distinguished and enlivened by mobile continental forms over a billion years, while Venus and many other worlds have not. It is noted that this ancient surface balance of land and sea is vitally crucial for a planet to become habitable for life and evolution. She consulted with R. Stern (UT Dallas), Jun Korenaga (Yale), Aubrey Zerkle (St. Andrews, Scotland)), and others as this rare Earth crustal and oceanic interplay grows in significance.
This volume brings together contributions from the Royal Society Discussion Meeting on ‘Earth dynamics and the development of Plate Tectonics’ held in March 2018. Plate tectonics is not seen on other planets, so why does it occur on Earth, and when did it start? The nature of tectonics depends on initial conditions, mantle thermal states, and an ability to weaken the lithosphere to allow plate boundaries to form. Geodynamic models, rock deformation experiments, models for growth of the continental crust, and evidence from the rock record are consistent with the development of plate tectonics from a single-lid state. Major changes occurred in the geological record near the end of the Archaean, suggesting that plate tectonics had become the dominant gobal regime by the Proterozoic. Modern plate tectonics and the generation of stable continents were key events in the evolution of the biosphere on Earth, and similar tectonic processes could be crucial for the development of habitability of exoplanets. (Synopsis)
Future > Self-Selection
The Great Silence: Science and Philosophy of Fermi’s Paradox.
Oxford: Oxford University Press,
The Astronomical Observatory of Belgrade and Future of Humanity Institute, Oxford University astrophysicist and author (search) provides a thorough study of possible answers to Enrico Fermi’s famous query: with an infinity of suns and assumed worlds, the cosmos ought to be filled with signs of their presence, but they are nowhere to be seen. Thus follows an eclectic list of solipsist, rare-earth, neo-catastrophic, logistic, and so on guesses – they are hiding, we are toxic, it’s a zoo, too many natural or viral dangers, stick with your home base, arrested development, technological annihilation and more. A theme then courses through – while a “Copernican principle” need be held to such that Earth is not in any central location, a closing phrase is Many are called, but few are chosen. Since Earth life has made it through an evolutionary “Gaian Window,” maybe we are special after all (I may be reading this in) so that efforts to achieve sustainability ought to proceed. See also Where is Everybody? by Stephen Webb (2015), /The Future of Humanity by Michio Kaku (2018) and On the Future by Martin Rees (2018) for other takes. So some seven decades later, as an Earthropic Principle conveys, me + We = US could well be the It from Bit as participatory cosmic cocreators.
The Great Silence explores the multifaceted problem named after the great Italian physicist Enrico Fermi and his legendary 1950 lunchtime question "Where is everybody?" In many respects, Fermi's paradox is the richest and the most challenging problem for the entire field of astrobiology and the Search for ExtraTerrestrial Intelligence (SETI) studies. The book shows how Fermi's paradox is intricately connected with many fields of learning, technology, arts, and even everyday life. It aims to establish the strongest possible version of the problem, to dispel many related confusions, obfuscations, and prejudices, as well as to offer a novel point of entry to the many solutions proposed in existing literature. Milan Cirković argues that any evolutionary worldview cannot avoid resolving the Great Silence problem in one guise or another. (Publisher)
Future > Self-Selection
Morbidelli, Alessandro, et al.
Topical Collection on the Delivery of Water to Proto-Planets, Planets and Satellites.
Space Science Reviews.
Eleven editors including Sean Raymond and Helmut Lammer introduce a special issue with this title about the occurrence, locales, and quantities of life’s ultimate biochemical through galactic, solar and planetary ages. Click on the issue citation for papers such as The Importance of Water for Life by Frances Westall and Andre Brack, The Delivery of Water during Terrestrial Planet Formation by David O.Brien, et al, Water in the Earth’s Interior by Anne Peslier, et al, and Water in Extrasolar Planets and Implications for Habitability by Lena Noack, et al.
Future > Self-Selection
To stay with this vital aspect, see for example The Role of Deep-Earth Water Cycling in the Growth and Evolution of Continental Crust by Zhen Li, et al in Lithos (302-303/126, 2018), Origin of Earth’s Water by Jun Wu, et al in Journal of Geophysical Research: Planets (online October 2018), A Nearly Water-Saturated Mantle Transition Zone by Hongzhan Fei, et al in Sciences Advances (June 2017) and Exoplanet Science Priorities form the Perspective of Internal and Surface Processes for Silicate and Ice Dominated Worlds by Wade Henning, et al at arXiv:1804.05094. By these entries and more, a natural genesis ecosmos seems to be present on its independent own and innately vivified so as to give rise to life, evolutionary, intelligence, this global retrospect and our procreative continuation.
Raymond, Sean, et al.
Solar System Formation in the Context of Extra-Solar Planets.
Senior astrophysicists SR, University of Bordeaux, Andre Izidoro, Sao Paulo State University and Alessandro Morbidelli, University of Nice (search each) post a strongest analysis to date that our home Earth-Sun spatial and temporal array seems to be a rarest long term orderly, benign, conducive milieu for life to evolve and develop to a personsphere intelligence able to reach this auspicious conclusion. At the cusp of 2020, here is an incredible finding in our midst with implications for the fate and future not only of a geonate EarthKinder, but on to a self-chosen Ecosmos.
Exoplanet surveys have confirmed one of humanity's worst fears: we are weird. If our Solar System were observed with present-day Earth technology -- to put our system and exoplanets on the same footing -- Jupiter is the only planet that would be detectable. The statistics of exo-Jupiters indicate that the Solar System is unusual at the ~1% level among Sun-like stars (or ~0.1% among all stars). But why are we different? We argue that most Earth-sized habitable zone exoplanets are likely to form much faster than Earth, with most of their growth complete within the disk lifetime. Their water contents should span a wide range, from dry rock-iron planets to water-rich worlds with tens of percent water. Jupiter-like planets on exterior orbits may play a central role in the formation of planets with small but non-zero, Earth-like water contents.
We present three models for inner Solar System formation -- the low-mass asteroid belt, Grand Tack, and Early Instability models -- each invoking a combination of migration and instability. We identify bifurcation points in planetary system formation. We present a series of events to explain why our Solar System is so weird. Jupiter's core must have formed fast enough to quench the growth of Earth's building blocks by blocking the flux of inward-drifting pebbles. The large Jupiter/Saturn mass ratio is rare among giant exoplanets but may be required to maintain Jupiter's wide orbit. The giant planets' instability must have been gentle, with no close encounters between Jupiter and Saturn, also unusual in the larger (exoplanet) context. Our solar system is thus the outcome of multiple unusual, but not unheard of, events. (Abstract)
The discovery of extra-solar planets demonstrated that the current Solar System-inspired paradigm of planet formation was on the wrong track. Most extra-solar systems bear little resemblance to our well-ordered Solar System. While the Solar System is radially segregated, with small inner rocky worlds and more distant giant planets, few known exo-systems follow the same blueprint. Models designed with the goal of reproducing the Solar System failed spectacularly to understand why other planetary systems looked different than our own. (1)