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Meccanica Analitica: Meccanica Classica, Meccanica Lagrangiana, Hamiltoniana, Teoria della Stabilità, Relatività Speciale (UNITEXT #164)
by Valter MorettiIl testo parte da una rivisitazione teorica della meccanica classica newtoniana e del suo linguaggio matematico che si conclude con un'analisi critica della meccanica classica newtoniana. Si passa quindi alle formulazioni lagrangiane e hamiltoniane della meccanica classica, discutendo in particolare il rapporto tra simmetrie e costanti del moto all'interno di varie versioni del teorema di Noether e analoghi risultati. I capitoli sulla meccanica hamiltoniana, oltre al materiale standard come le parentesi di Poisson, la geometria simplettica, la formulazione di Hamilton-Jacobi e principi variazionali, includono alcuni risultati teorici importanti come il teorema di Liouville e il teorema di ricorrenza di Poincaré. La teoria della stabilità è introdotta e discussa nell'approccio di Lyapunov. Nella seconda edizione è stata aggiunta una descrizione matematica della teoria della relatività speciale e di alcuni suoi sviluppi nell'ambito della formulazione lagrangiana ed hamiltoniana. Il linguaggio adottato in tutto il testo è quello della geometria differenziale, che in ogni caso viene introdotta gradualmente. Un primo complemento finale discute gli assiomi fisici su cui si basa la teoria della relatività speciale e come si passa da tali assiomi alla formulazione matematica. Un secondo complemento include la teoria di base dei sistemi di equazioni differenziali ordinarie e dei sistemi con alcune generalizzazioni alla teoria sulle varietà. Diverse appendici introducono alcuni strumenti matematici come la teoria delle forme differenziali, la derivata di Lie e la teoria dell'integrazione su varietà. Il libro include diversi esercizi risolti. Il libro si rivolge agli studenti di Matematica e Fisica per i corsi di Meccanica Razionale e Meccanica Analitica.
Mechanical Behavior and Damage Fracture Mechanism of Deep Rocks
by Sheng-Qi YangThis book presents mainly experimental studies on the mechanical behavior and damage fracture mechanism of deep rocks including sandstone, marble, mudstone and granite, combining with several advanced technologies of X-ray micro-CT and AE monitoring.It has several unique features: 1) Investigates the influence of loading path on triaxial strength and deformation behavior of sandstone and marble; 2) Analyzes the effect of borehole size on triaxial strength and deformation behavior of hollow sandstone; 3) Explores the influence of high temperature on triaxial deformation and permeability behavior of sandstone and granite; 4) to reveal the damage fracture mechanism of deep rocks using spatial AE techniques and X-ray micro CT observations. This work will appeal to a wide readership from technicians in the field of geotechnical engineering and engineering geology to scholars carrying out research in the rock mechanics.
The Mechanical Behavior of Salt – Understanding of THMC Processes in Salt: Proceedings of the 6th Conference (SaltMech6), Hannover, Germany, 22–25 May 2007
by Manfred Wallner Karl-Heinz Lux Wolfgang Minkley H. Reginald HardyA unique opportunity to review the latest progress in an expanding area of interest: the Mechanical Behaviour of Salt. These Proceedings include over fifty papers and summaries describing the latest findings in ongoing studies from a number of research groups. For the 2007 conference, there was a particular focus on the understanding of thermal, mechanical, hydraulic and chemical coupled processes (THMC). Such processes are of specific interest when considering advanced problems in waste disposal, storage and mining. The book includes a number of themes: - laboratory and in-situ investigations modelling, e.g. derivation of constitutive equations - numerical computations and prediction of long-term behaviour - THMC processes in mining projects, storage and permanent disposal - case studies - geology - mining and storage applications and abandonment The International Conferences on the Mechanical Behaviour of Salt have a long tradition, being initiated in 1981 at The Pennsylvania State University, USA. The present conference, the sixth of the series, took place in Hannover, Germany, in May 2007. The conference brought together mining engineers, researchers, and university professors interested in the mechanical behaviour of salt, mostly from Europe and beyond.
The Mechanical Behavior of Salt X: PROCEEDINGS OF THE 10TH CONFERENCE ON THE MECHANICAL BEHAVIOR OF SALT (SALTMECH X), UTRECHT, THE NETHERLANDS, 06-08 JULY 2022
by J.H.P. de BresserRock salt formations have long been recognized as a valuable resource - not only for salt mining but for construction of oil and gas storage caverns and for isolation of radioactive and other hazardous wastes. Current interest is fast expanding towards construction and re-use of solution-mined caverns for storage of renewable energy in the form of hydrogen, compressed air and other gases. Evaluating the long term performance and safety of such systems demands an understanding of the coupled mechanical behavior and transport properties of salt. This volume presents a collection of 60 research papers defining the state-of-the-art in the field. Topics range from fundamental work on deformation mechanisms and damage of rock salt to compaction of engineered salt backfill. The latest constitutive models are applied in computational studies addressing the evolution and integrity of storage caverns, repositories, salt mines and entire salt formations, while field studies document ground truth at multiple scales. The volume is structured into seven themes: Microphysical processes and creep models Laboratory testing Geological isolation systems and geotechnical barriers Analytical and numerical modelling Monitoring and site-specific studies Cavern and borehole abandonment and integrity Energy storage in salt caverns The Mechanical Behavior of Salt X will appeal to graduate students, academics, engineers and professionals working in the fields of salt mechanics, salt mining and geological storage of energy and wastes, but also to researchers in rock physics in general.
Mechanical Behaviour of Salt VIII
by Lance Roberts Kirby Mellegard Frank HansenTechnical contributions contained in this volume characterize continuity of science, engineering and modeling regarding the mechanical behavior of salt. These papers evidence relationships from microscopic dislocation structure to modeling applications over kilometer dimensions, a reach of more than ten orders of magnitude. The book is arranged alo
Mechanical Excavation in Mining and Civil Industries
by Nuh Bilgin Hanifi Copur Cemal BalciThe secret to streamlined project scheduling is a solid understanding of basic rock cutting mechanics. Comparing theoretical values with experimental and real-world results, Mechanical Excavation in Mining and Civil Industries explains rock cutting theories for chisel, conical, disc, and button cutters. The authors provide numerical examples on the effect of independent variables on dependent variables, as well as examples from real-life mining and civil engineering jobs. The book assists students and engineers in machinery selection and performance prediction, and discusses rock cutting mechanics and mechanical miners.
Mechanical Ice Drilling Technology
by Pavel G. TalalayThis book provides a review of mechanical ice drillingtechnology, including the design, parameters, and performance of various toolsand drills for making holes in snow, firn and ice. The material presents the historicaldevelopment of ice drilling tools and devices from the first experience takenplace more than 170 years ago to the present day and focuses on the modernvision of ice drilling technology. It is illustrated with numerous pictures, many of them published for the first time. This book is intended for specialistsin ice core sciences, drilling engineers, glaciologists, and can be useful forhigh-school students and other readers who are very interested in engineeringand cold regions technology.
Mechanics
by Ioan Merches Masud Chaichian Anca TureanuMechanics is one of the oldest and at the same time newest disciplines, in the sense that there are methods and principles developed first in mechanics but now widely used in almost all branches of physics: electrodynamics, quantum mechanics, classical and quantum field theory, special and general theory of relativity, etc. More than that, there are some formalisms like Lagrangian and Hamiltonian approaches, which represent the key stone for the development of the above-mentioned disciplines. During the last 20-25 years, classical mechanics has undergone an important revival associated with the progress in non-linear dynamics, applications of Noether's theorem and the extension of variational principles in various interdisciplinary sciences (for instance, magnetofluid dynamics). Thus, there ought to exist a book concerned with the applied analytical formalism, first developed in the frame of theoretical mechanics, which has proved to be one of the most efficient tools of investigation in the entire arena of science.The present book is an outcome of the authors' teaching experience over many years in different countries and for different students studying diverse fields of physics. The book is intended for students at the level of undergraduate and graduate studies in physics, engineering, astronomy, applied mathematics and for researchers working in related subjects. We hope that the original presentation and the distribution of the topics, the various applications in many branches of physics and the set of more than 100 proposed problems, shall make this book a comprehensive and useful tool for students and researchers. The present book is an outcome of the authors' teaching experience over many years in different countries and for different students studying diverse fields of physics. The book is intended for students at the level of undergraduate and graduate studies in physics, engineering, astronomy, applied mathematics and for researchers working in related subjects. We hope that the original presentation and the distribution of the topics, the various applications in many branches of physics and the set of more than 100 proposed problems, shall make this book a comprehensive and useful tool for students and researchers.
Mechanics
by Florian ScheckPurpose and Emphasis. Mechanics not only is the oldest branch of physics but was and still is the basis for all of theoretical physics. Quantum mechanics can hardly be understood, perhaps cannot even be formulated, without a good knowledge of general mechanics. Field theories such as electrodynamics borrow their formal framework and many of their building principles from mechanics. In short, throughout the many modem developments of physics where one fre quently turns back to the principles of c1assical mechanics its model character is feIt. For this reason it is not surprising that the presentation of mechanics reflects to some extent the development of modem physics and that today this c1assical branch of theoretical physics is taught rather differently than at the time of Arnold Sommerfeld, in the 1920s, or even in the 1950s, when more emphasis was put on the theory and the applications of partial-differential equations. Today, symme tries and invariance principles, the structure ofthespace-time continuum, and the geometrical structure of mechanics play an important role. The beginner should realize that mechanics is not primarily the art of describing block-and-tackles, coIIisions of billiard balls, constrained motions of the cylinder in a washing ma chine, or bicycle riding.
Mechanics and Geometry of Enriched Continua
by Luis EspathThis monograph presents a comprehensive and rigorous new framework for the theoretical description and modelling of enriched continua. In other words, continua that exhibit more complex behaviour than their conventional counterparts and, in particular, multicomponent systems. It employs gradient theories, exhibiting multiple transition layers described by phase fields. As a point of departure, we account for multiple continuum kinematic processes, including motion and various phase fields. These gradient theories arise by considering various kinematic processes which are tightly linked to the level of the arbitrariness of the Euler–Cauchy cuts. The surface defining the Euler–Cauchy cut may lose its smoothness along a curve, and the curve may also lose its smoothness at a point. Additionally, we postulate the principle of virtual power on surfaces. Then, the first and second laws of thermodynamics with the power balance provide suitable and consistent choices for the constitutive equations. Finally, the complementary balances, namely the balances on surfaces, are tailored to coincide with different parts of the boundaries of the body. These surface balances are then called environmental surface balances and aid in determining suitable and consistent boundary conditions. Ultimately, the environmental surface power balance is relaxed to yield an environmental surface imbalance of powers, rendering a more general type of boundary condition.A detailed introduction sets the scene for the mathematical chapters that follow, ensuring that graduate students and newcomers can profit from the material presented.
Mechanics of Bio-Sediment Transport
by Wei Cheng Hongwei Fang Lei Huang Huiming Zhao Yishan Chen Mehdi Fazeli Qianqian ShangThe main focus of this book is the transport mechanics of sediment particles coated with microbial biofilm, which is called bio-sediment. The book also addresses the question of how to measure and simulate the considerable variation in the properties of natural sediment associated with microbial biofilm, ranging from the micro-scale surface morphology to the macro-scale sediment transport. Nowadays most studies to elucidate the mechanisms of sediment transport have concentrated on physical-chemical sediment properties, little work explicitly coupled sediment dynamics and the environmental effects under the influence of micro-ecosystem, thus leaving a serious gap in water and sediment sciences as well as water ecological research. With respect to physical-chemical sediment properties, this book has been undertaken to evaluate and quantify the effect of biological factors - biofilm on sediment transport mechanics. The chapters cover topics including development of bio-sediment and its properties; model of biofilm growth on sediment substratum; bedform and flow resistance of bio-sediment bed; incipient velocity and settling velocity of bio-sediment; bedload and suspended load transport for bio-sediment; numerical simulation of bio-sediment transport. Besides, the measurement technology, analysis method and expression approach introduced in this book combine the characteristics of hydraulic, environmental and microbial research, having more immediate innovation. This book will be of interest to researchers, managers, practitioners, policy and decision makers, international institutions, governmental and non-governmental organizations, educators, as well as graduate and undergraduate students in the field of hydraulics and river dynamics. It will help to understand the relevance of sediment transport and biofilm growth under the role of aqueous micro-ecosystem, to introduce better tools for the simulation and prediction of bio-sediment transport, and to provide a scientific basis and application foundation for the research of interaction between sediment particles and ecological and environmental factors.
The Mechanics of Earthquakes and Faulting
by Christopher H. ScholzThis essential reference for graduate students and researchers provides a unified treatment of earthquakes and faulting as two aspects of brittle tectonics at different timescales. The intimate connection between the two is manifested in their scaling laws and populations, which evolve from fracture growth and interactions between fractures. The connection between faults and the seismicity generated is governed by the rate and state dependent friction laws - producing distinctive seismic styles of faulting and a gamut of earthquake phenomena including aftershocks, afterslip, earthquake triggering, and slow slip events. The third edition of this classic treatise presents a wealth of new topics and new observations. These include slow earthquake phenomena; friction of phyllosilicates, and at high sliding velocities; fault structures; relative roles of strong and seismogenic versus weak and creeping faults; dynamic triggering of earthquakes; oceanic earthquakes; megathrust earthquakes in subduction zones; deep earthquakes; and new observations of earthquake precursory phenomena.
The Mechanics of Earthquakes and Faulting
by Christopher H. ScholzOur understanding of earthquakes and faulting processes has developed significantly since publication of the successful first edition of this book in 1990. This revised edition, first published in 2002, was therefore thoroughly up-dated whilst maintaining and developing the two major themes of the first edition. The first of these themes is the connection between fault and earthquake mechanics, including fault scaling laws, the nature of fault populations, and how these result from the processes of fault growth and interaction. The second major theme is the central role of the rate-state friction laws in earthquake mechanics, which provide a unifying framework within which a wide range of faulting phenomena can be interpreted. With the inclusion of two chapters explaining brittle fracture and rock friction from first principles, this book is written at a level which will appeal to graduate students and research scientists in the fields of seismology, physics, geology, geodesy and rock mechanics.
Mechanics of Oil and Gas Flow in Porous Media
by Dang Li Junbin ChenThis book discusses various aspects of percolation mechanics. It starts with the driving forces and driving modes and then examines in detail the steady state percolation of single-phase incompressible fluids, percolation law of natural gas and percolation of non-Newtonian fluids. Progressing from simple to complex concepts, it also analyzes Darcy’s law, providing a basis for the study of reservoir engineering, oil recovery engineering and reservoir numerical simulation. It serves as a textbook for undergraduate students majoring in petroleum engineering, petroleum geology and groundwater engineering, and offers a valuable reference guide for graduate students, researchers and technical engineers engaged in oil and gas exploration and development.
Mechanics of Residual Soils
by Charles SidebottomResidual soils are found in many parts of the world and are used extensively as construction materials for roads, embankments and dams, and to support the foundations of buildings, bridges and load-bearing pavements. The characteristics and engineering properties of residual soils can differ significantly from those of the more familiar transported
Mechanics of Wave-Seabed-Structure Interactions: Modelling, Processes And Applications (Cambridge Ocean Technology Series #7)
by Dong-Sheng JengOpening with recent advances in both the theoretical and physical models for wave-seabed-structure interactions, this book provides an updated look at the mathematics behind the interactions between sea, soil and man-made structures.<P><P>The main models are broken down into key equations, and their strengths and challenges are discussed. These models are then placed in context with industry-relevant examples, in both two and three dimensions. From seabed instability around offshore wind turbines, to soil conditions in response to the laying of submarine pipelines, this book takes a comprehensive look at a variety of wave-seabed-structure interactions. With important implications for the future of offshore infrastructure, this is an ideal resource for industry workers, undergraduate students, and researchers.<P> Focuses on integrated wave and seabed models, and marine infrastructures, in 2D and 3D.<P> Providing detailed descriptions of industry-relevant implications of soil instability due to marine infrastructure, the book is a vital resource for anyone in the geotechnical engineering field.<P> Includes updated and integrated models for seabed-structure interactions and the compiling effects of wave action, providing an easy basis for research.
Mechanik – smart gelöst
by Peter KerstenDieses Buch bietet Studierenden in MINT-Fächern eine optimale Hilfestellung beim Erlernen der Grundlagen der Physik. Typische Aufgaben der Mechanik werden dabei Schritt für Schritt erklärt und mit Hilfe leistungsstarker Software aus den Bereichen Tabellenkalkulation, Computeralgebra und technisch-wissenschaftlichem Rechnen gelöst. Die dabei verwendeten Programme (Excel®, der Internetdienst Wolfram|Alpha® sowie die Software MATLAB®) sind sowohl auf Desktop-Rechnern, als auch als Apps auf mobilen Endgeräten wie Smartphones oder Tablets verfügbar – und damit immer schnell zur Hand. Das Fähigkeit mit diesen Programmen zu arbeiten kann auch im weiteren Studienverlauf und später in der beruflichen Praxis von großen Nutzen sein. Nach einer kompakten Einführung in mathematische Methoden und die verwendeten Programme deckt das Buch dabei die Bereiche der klassischen Mechanik mit den Teilgebieten Kinematik und Dynamik ab und liefert somit eine ideale Unterstützung für Einführungsvorlesungen in Physik an Hochschulen. Allen Studierenden, die sich beim Lösen von Aufgaben in der Physik schon einmal eine kleine Hilfestellung gewünscht haben, die einfach mal einen Funktionsverlauf visualisieren, eine Gleichung ohne Papier und Bleistift lösen oder das eigene Rechenergebnis überprüfen möchten, wird das vorliegende Buch ein praktischer und wertvoller Begleiter sein.
Mechanism-Based Assessment of Structural and Functional Behavior of Sustainable Cottonid (Werkstofftechnische Berichte │ Reports of Materials Science and Engineering)
by Ronja Victoria ScholzRonja Victoria Scholz assesses the performance of cellulose-based Cottonid for implementation as sustainable construction material. Quasi-static and fatigue tests are performed in varying hygrothermal test conditions using mechanical testing systems in combination with integrable climate chambers. To investigate humidity-driven actuation properties, customized specimen holders are designed. Accompanying microstructural in situ experiments in analytical devices enable a profound understanding of effective material-specific damage and failure mechanisms. The findings are transferred into strength-deformation diagrams as well as Woehler curves, which enable a comparative evaluation of several process-related and environmental influencing factors and can directly be used for dimensioning of Cottonid elements for structural applications. The interpretation of thermoelastic material reponse during loading is used as scientific value for lifetime prediction. Comprehensive investigations on industrial standard materials as well as structurally optimized Cottonid variants provide a scientific basis for categorizing material’s structural and functional performance towards common technical plastics and wood.
Mechanism of Hairpin Vortex Formation by Liutex (Synthesis Lectures on Engineering, Science, and Technology)
by Yifei Yu Chaoqun LiuThis book presents the importance of the mechanism of hairpin vortex formation to understanding flow transition, turbulence, and flow control. This book blends direct numerical simulation (DNS) and mathematical analysis with experiments to create a foundation for understanding turbulence. The authors discuss hairpin vortex as a main component of transitional flow and turbulent flow. In addition, Liutex is utilized and described as a theoretical system that presents valid tools for turbulence research. Readers are exposed to understanding 3D and non-linear instability; the Lambda vortex formation; sweeps, ejections, and shear instability; the Kelvin-Helmholtz instability and vortex ring formation; and turbulence generation and sustenance.
Mechanisms for Long-Term Innovation: Technology and Business Development of Reverse Osmosis Membranes (Advances in Japanese Business and Economics #31)
by Masatoshi Fujiwara Yaichi AoshimaThis book explores how a long-term innovation can take place based on historical analyses of the development of reverse osmosis (RO) membrane from the early 1950s to the mid-2010s. The RO membrane is a critical material for desalination that is a key to solve water shortages becoming serious in many places of the world. The authors conducted in-depth field studies as well as analyses of rich archival data to demonstrate how researchers, engineers, managers, entrepreneurs, and policymakers interacted each other for this material innovation to be realized. A series of historical analyses in this book uncovered that initial government supports, strategic niche markets, emergence of breakthrough technology, and company-specific rationales played significant roles for companies to overcome four types of uncertainty, technological, market, competition, and social/organizational ones, and enabled the companies to persistently invest in the development and commercialization of the RO membrane. This book depicts that innovation does not arise on a sudden, but that it is actualized through long lasting process with turns and twists, which is driven by many non-economic rationales beyond economic motives.
Mechanisms of Arsenic Toxicity and Tolerance in Plants
by Mirza Hasanuzzaman Kamrun Nahar Masayuki FujitaArsenic is likely the most talked-about metalloid in the modern world because of its toxic effects on both animal and plants. Further, arsenic pollution is now producing negative impacts on food security, especially in many south Asian countries. Since plants are a major food source, their adaptation to As-rich environments is essential, as is being informed about recent findings on multifarious aspects of the mechanisms of arsenic toxicity and tolerance in plants. Although numerous research works and review articles have been published in journals, annual reviews and as book chapters, to date there has been no comprehensive book on this topic.This book contains 19 informative chapters on arsenic chemistry, plant uptake, toxicity and tolerance mechanisms, as well as approaches to mitigation. Readers will be introduced to the latest findings on plant responses to arsenic toxicity, various tolerance mechanisms, and remediation techniques. As such, the book offers a timely and valuable resource for a broad audience, including plant scientists, soil scientists, environmental scientists, agronomists, botanists and molecular biologists.
Mechanisms of Forest Ecosystems Sustainability in a Changing Climate: Complete Triad of Ecological Monitoring
by Erland G. KolomytsThe author's working concept of geo-ecological monitoring is presented. For the first time, the full triad of monitoring in its classical definition is considered: "observation (state assessment) – control (prediction) – management (adaptation, feedback, regulation)". The strategic goal of described monitoring research is to reveal the environmental otential of sustainablility of forest ecosystems in the context of modern global warming. The monograph expounds the main statements of author’s topo-ecological predictive concept: “Global Changes on the Local Level”, as a basis of ground bio-ecological and geosystem monitoring of natural ecosystems under global anthropogenic climatic changes. This concept makes it possible to carry out local empirical simulation of the regional bioclimatic trend and thereby reveal the mechanisms of transmission of global and regional climate signals to the local level. On the example of the Volga River basin, predictive empirical-statistical models of the carbon balance of forest ecosytems are presented under conditions of a changing climate. The carbon content in various pools of boreal and nemoral forests were calculated. The global climate models give prognostic estimates of the components of them carbon balance. A quantitative assessment of the ecological resources of forest formations that provide the environment sustainability through mechanisms of regulation of the carbon cycle is given. The adaptation of forest ecosystems to climate change is described through the calculated parameters of their functional sustainability.
Mechanized Tunnelling in Urban Areas: Design methodology and construction control
by Vittorio Guglielmetti Piergiorgio Grasso Ashraf Mahtab Shulin XuInternationally, the mechanized excavation of tunnels has intensified in the last two decades, as the number of tunnels being constructed for subways and railway underpasses increases. The subject of mechanized tunnelling in urban areas has not previously received the attention that it deserves, despite there being specific hazards associated with the construction of tunnels in metropolitan areas, including poor ground conditions, water tables higher than the level of tunnels, and subsidence leading to damage to the existing structures on the surface. The application of technologies for achieving the stability of the tunnel and for minimizing surface settlement is described in this book. Accurate characterization of the ground; rigorous assessment and management of risk from design to maintenance; the correct choice of a tunnel boring machine and a plan for the advancement of the tunnel; specific excavation procedures and real-time monitoring of excavation parameters are all discussed in this thorough work.
Mechatronics 4.0: Proceedings of the First International Workshop on Mechatronics 4.0, June 8–9, 2019, Mahdia, Tunisia (Lecture Notes in Mechanical Engineering)
by Maher Barkallah Jean-Yves Choley Jamel Louati Omar Ayadi Fakher Chaari Mohamed HaddarThis book gathers original findings, both theoretical and experimental, related to various cutting-edge topics in the design and modeling of mechatronic systems, including multiphysics problems. It presents peer-reviewed papers from the first installment of the Mechatronics 4.0 workshop, which was jointly organized by the Laboratory of Mechanics, Modeling and Manufacturing (LA2MP), National School of Engineers of Sfax, Tunisia, and the QUARTZ Laboratory, Higher Institute of Mechanics of Paris, SUPMECA, France. The event follows in the tradition of the Workshop on Mechatronic Systems (JSM2014), organized by the same universities, while shifting the focus to the concept of Industry 4.0. As this new type of industry is emerging as the convergence of the virtual world, digital design, and management with real-world products and objects, the chapters gathered here highlight recent work on mechatronics systems that are expected to help shape the industry of tomorrow. Thanks to a healthy balance of theory and practical findings, the book offers a timely snapshot for the research and industrial communities alike, as well as a bridge to facilitate communication and collaboration between the two groups.
The Medea Hypothesis: Is Life on Earth Ultimately Self-Destructive?
by Peter WardIn The Medea Hypothesis, renowned paleontologist Peter Ward proposes a revolutionary and provocative vision of life's relationship with the Earth's biosphere--one that has frightening implications for our future, yet also offers hope. Using the latest discoveries from the geological record, he argues that life might be its own worst enemy. This stands in stark contrast to James Lovelock's Gaia hypothesis--the idea that life sustains habitable conditions on Earth. In answer to Gaia, which draws on the idea of the "good mother" who nurtures life, Ward invokes Medea, the mythical mother who killed her own children. Could life by its very nature threaten its own existence? According to the Medea hypothesis, it does. Ward demonstrates that all but one of the mass extinctions that have struck Earth were caused by life itself. He looks at our planet's history in a new way, revealing an Earth that is witnessing an alarming decline of diversity and biomass--a decline brought on by life's own "biocidal" tendencies. And the Medea hypothesis applies not just to our planet--its dire prognosis extends to all potential life in the universe. Yet life on Earth doesn't have to be lethal. Ward shows why, but warns that our time is running out. Breathtaking in scope, The Medea Hypothesis is certain to arouse fierce debate and radically transform our worldview. It serves as an urgent challenge to all of us to think in new ways if we hope to save ourselves from ourselves.