Habitability of the Universe before Earth

Front
Cover
Half-Title Page
Habitability of the Universe
before Earth
Copyright
Dedications
	References
	Further Reading
Contents
Contributors
Preface: Life as a Cosmic Phenomenon by Alexei A. Sharov & Richard Gordon
	Part I. Physical and Chemical Constraints
	Part II. Predicting Habitability
	Part III. Life in the Cosmic Scale
	Part IV. System Properties of Life
	SUMMARY AND EXTRAPOLATIONS
	References
Part 1. PHYSICAL AND
CHEMICAL
CONSTRAINTS
Gravity and Life
	Introduction
	Gravity as Source of Complexity
	The Planet-Builder Force
	The Goldilocks Gravity
	Gravitational Biology
	A Scalable Life?
	The Plurality of Earth-Like Gravities
	Acknowledgments
	References
	Further Reading
Radiation as a Constraint for Life in the Universe
	Introduction
	Types of Radiation
	Sources of High-Energy Radiation
		Stellar Emissions
		Stellar Explosions
	Effects
		Direct Effects
		Indirect Effects
	Rates
	Conclusions
	Acknowledgments
	References
	Further Reading
The When and Where of Water in the History of the Universe
	Introduction. Why is Water Essential for Life?
	What Is Water?
		Chemical Properties of Water
		Physical Properties
	When Did Water Appear?
		Primordial Nucleosynthesis
		Energy Production in Stars
		Stellar Nucleosynthesis
		Water Molecule
	Distribution of Water in the Universe
		Water in Galaxies
		Water in Stars and Interstellar Space
		Water in Planetary Disks
		Water in Extrasolar Planets
		Water in the Solar System
			Water in the outer solar system
			Water in small bodies
				Comets
				Asteroids
				Meteorites
			Water on Earth and other terrestrial planets
				Mercury
				Venus
				Earth
				Mars
	Water and Life
	Acknowledgments
	References
	Further Reading
The Cosmic Evolution of Biochemistry
	Big Bang to Pale Blue Dots
	The First Stars: The Increasing Metallicity of POP III and POP II stars
	The Influence of C/O on the Rocky Planet Composition
	The Ubiquity of Habitable Planetary Systems
	What Can Terrestrial Life Tell us About Extraterrestrial Life?
	Conclusion
	References
Astrophysical and Cosmological Constraints on Life
	Introduction
		Formation of the Elements of Life
		Protection of Life on Planets
		Assumptions
	Hazardous Radiation and Particles
		Solar/Stellar Energetic Particles (SEPs)
		Galactic Cosmic Rays (GCRs)
		Extragalactic Cosmic Rays (EGCRs)
		The Star Formation Rate (SFR)
	Local Astrophysical Threats to Life
		Supernovae (SNe)
		Gamma-Ray Bursts (GRBs)
		Nearby Super-Massive Black Holes (SMBHs)
		Galaxy Mergers and SMBH Mergers
		AGN, SMBHs, and Ultra-Luminous X-Ray Sources (ULXs)
		The Galactic Center SMBH
	Planetary Protection
		The Rise of the Elements
		Galactic Magnetic Fields: Protection From EGCRs
		Astrospheres: Protection From GCRs
		Planetary Magnetic Fields: Protection From GCRs and SEPs
		The Atmosphere: A Strong Last Line of Protection
	Habitability in Space and in Time
		The Super-Galactic Habitable Zone (SGHZ)
		The Galactic Habitable Zone (GHZ)
		The Circumstellar Habitable Zone
	Life as We Know It in the Universe
	Summary of Conclusions
	References
	Further Reading
Primitive Carbon: Before Earth and Much Before Any Life on It
	Introduction: The Foundational Carbon
	Viewing the First Billion Years of the Universe
	The Origin of Metallicity
		Brief Overview of POP-II Stars
		Carbon-Enhanced Metal Poor Stars
	Carbon: The Reactant and Substrate in the Early Universe
		Carbon Monoxide: The Reactant
		Carbonaceous Dust: The Substrate
		Dust-Grain Interaction: Escalating Organic Enrichment
	Finding Organics: Analogues of High-Redshift Galaxies in the Local Universe
		Signatures of Organics in the Local Universe
		AGB Stars: Refuge for Organics?
	Conclusion: Where Does the Science of Origins of Habitability Go from Here?
		The First Yardstick of Finding Habitability in the Ancient Universe
		The Cutting-Edge Science of Origins
	Acknowledgments
	References
Part 2. PREDICTING HABITABILITY
The Habitability of Our Evolving Galaxy
	Introduction
	Habitability
	The Exoplanet Era
	The Habitability of the Milky Way
	The Habitability of Other Galaxies
	Transient Radiation Events
	The Habitability of the Galaxy Before the Earth
	Conclusions and Future Outlook
	References
N-Body Simulations and Galactic Habitability
	Framing the Big Question: Where Are We?
	Habitability Properties
		Metallicity
		Star Formation Rate
		Dynamical Properties
		The Galactic Habitable Zone
	N-Body Simulations: Galactic Habitability in Dynamical Perspective
		Description
		Metallicity and SFR
		Model Accuracy and Limitations
	Simulations
		General Description
		Habitability Calculations
			Model 1
			Model 2
		Comparison of Models
		Results
			Model 1
			Model 2
		Habitability Before the Earth Was Formed
		Discussion
	Comparison With Other Studies
		Habitability of Other Galaxies in the Dynamical Perspective
	Conclusions and Future Prospects
	Acknowledgments
	References
Occupied and Empty Regions of the Space of Extremophile Parameters
	Introduction
	Parameter Space of Extremophilic Organisms on Earth
		Hyperthermophiles
		Psychrophiles
		Extreme Halophiles
		Tolerance for Low Water Activity
		pH Extremophiles
		Missing Life in Poly-Extremophilic Parameter Spaces
		Radiation- and Pressure-Resistant Extremophiles: Parameter Spaces Analogous to the Interstellar Medium
			Radiation
			High Pressure: Mega-Pascal and Giga-Pascal Ranges
			Vacuum and Low Pressure
			Microbial Metabolism
	Settings for Life in our Solar System: Physiochemical Parameter Space on Mars, Europa, Titan, and Enceladus
		Mars
		Europa: ``Earth-like´´ Subsurface Ocean
		Titan and Enceladus: Active Cryovolcanism on Moons of Saturn
		Settings for Life in our Solar System: Plausible Ecosystems Based on Analog Niches
	Conclusion
	References
	Further Reading
The Emergence of Structured, Living, and Conscious Matter in the Evolution of the Universe: A Theory of Structural Evolution a
	Introduction
	The Physics of Matter and Structural Evolution
	Building the Biostructure: The Mystery of Life
	The Rhythms in the Dynamics of Structured Matter
	The Emergence of Intelligence
	Microstructural Evolution, Learning, Self-Organization, and Semantics
	What is Balanced Excitation and Inhibition?
	The Genetic Basis of Brain Disorders and Aging
	On the Origin of Time, Matter, and Intelligence of Life
	What is Holding us Back in Artificial Intelligence?
	Incomplete Models, the Theory of Everything
	Summary of Theoretical Concepts-New Predictions
	Conclusion
	Acknowledgments
	References
	Further Reading
Part 3. LIFE IN THE
COSMIC SCALE
Life Before Earth
	The Increase of Genetic Complexity Follows Moore's Law
	The Age of Life Is Estimated Based on Moore's Law
	How Variable Are the Rates of Evolution?
	Why Did Genome Complexity Increase Exponentially?
	Could Life Have Started From the Equivalent of One Nucleotide?
	How Heritable Surface Metabolism May Have Evolved Into an RNA-World Cell?
	How Can Organisms Survive Interstellar Transfer?
	Implications of the Cosmic Origin of Life on Earth
	Genetic Complexity Lags Behind the Functional Complexity of Mind
	Extrapolating the Growth of Complexity Into the Future
	A Biosemiotic Perspective
	Conclusion
	Acknowledgments
	References
Earth Before Life*
	Background
	Method
		Regression Effect
		Regression Dilution
		Estimating Measurement Errors
	Results and Discussion
	Conclusions
	Acknowledgments
	References
The Drake Equation as a Function of Spectral Type and Time
	Introduction
	Constraints From Observations
		Rate of Star Formation
		Fraction of Stars With Planets
		Number of Habitable Planets Per System
	Constraints From Theory
		Fraction of Habitable Planets That Develop Life
		Fraction of Life-Bearing Planets That Develop Intelligence
		Fraction of Intelligence-Bearing Planets That Become Communicative
	Rethinking the Longevity Parameter
		Equal Evolutionary Time
		Proportional Evolutionary Time
	Discussion
	Conclusion
	References
Are We the First: Was There Life Before Our Solar System?
	Introduction
	The Big Bang and the Elements
	Interstellar Medium-Holes in the Sky
	Making Organic Molecules-Cradle for Life?
		Astrochemistry
		Atmospheric Boundaries
		Clay and Mineral Surfaces
		Atmospheric Lightning
	Origin of Life per se: Current Hypotheses
		Panspermia Hypothesis
		Metabolism First Hypothesis
		Genetics First Hypothesis
		Vesicles First Hypothesis
	The Virus Connection
	Extremophiles-The Resilience of Life
	Balance of Probability: Life Before Our Solar System
	Final Say-Best Fit Solution?
	References
Life Before its Origin on Earth: Implications of a Late Emergence of Terrestrial Life
	Introduction
		Time Available Before the Emergence of Life on Earth
		Rationalizing Our Origins in Terms of Thermodynamics
	How Would We See Ourselves if Early Origins are Identified?
		Approaching the End of Biocentrism if Life on Earth is a Latecomer
		Anthropocentrism
	Philosophical Comments on an Early ``Forest of Life´´
		Process Philosophy
		Stellar Evolution
		Cultural Comments on an Early Forest of Life
	Terrestrial Life as a Latecomer in Cosmic Evolution
	Conclusion
	References
	Further Reading
Part 4. SYSTEM PROPERTIES OF LIFE
Symbiosis: Why Was the Transition from Microbial Prokaryotes to Eukaryotic Organisms a Cosmic Gigayear Event?
	Introduction
	Eukaryogenesis as Symbiosis
	Order of Events Resulting in Eukaryotes
	What on Earth Happened When Prokaryotes Were Its Only Habitants?
	Why Did It Take So Long for Eukaryotes to Appear on Earth?
		Geophysiochemical Waiting
		Biological Waiting
	Semantic Approaches to Eukaryogenesis
	Evolution of Prokaryotes Prior to Eukaryogenesis
	Conclusion
	Acknowledgments
	References
Coenzyme World Model of the Origin of Life
	Introduction
	Problems With Existing Models of the Origin of Life
	Components, Functions, and Evolution of First Living Systems
		Life on the Surface
		Evolutionary Potential of the Coenzyme World
		Diversification of Molecular Communities
	Evolution From Oil Droplets to LUCA
		Template-Based Replication
		Bilayer Membrane
		Chromosomes
		Protein Synthesis
	Discussion
	Acknowledgments
	References
Emergence of Polygonal Shapes in Oil Droplets and Living Cells: The Potential Role of Tensegrity in the Origin of Life
	Introduction
	Shaped Droplets
	Oil-Based Protocells
	Polygonal Prokaryotes
	Mechanisms Controlling the Shapes of Prokaryote Cells
	Possible Functions of a Polygonal Shape of Cells
	Polygonal Diatoms
	Conclusion
	Acknowledgments
	Overview of Tensegrity Structures
	A Toy Model for the Polygonal Shape of Shaped Droplets
	References
	Further Reading
Why on Theoretical Grounds It Is Likely that ``Life´´ Exists Throughout the universe
	Introduction
	Closing the Observation Gap
		Measurements
		Statistics
	Closing the Definition Gap
		Operator Hierarchy
		O-life
		S-life
	Analyzing the Use of Epochs
	Why on Theoretical Grounds It Is Likely that ``Life´´ Exists Throughout the Universe
		What Does the Concept of ``Life´´ Refer To?
		Can Definitions of O-life or S-life be Generalized to Extra-Terrestrial Situations?
		Can the Concept of ``Life As We Dont Know´´ Be Specified?
		What Theoretical Reasoning Supports the Likelihood of ``Lifes´´ Existence Throughout the Universe?
	Discussion
		Organisms, O-life and S-life
		Life As We Dont Know
		What Can Be Added to Current Epoch Systems?
	Conclusions
	References
	Further Reading
Glossary
Index
	A
	B
	C
	D
	E
	F
	G
	H
	I
	J
	K
	L
	M
	N
	O
	P
	Q
	R
	S
	T
	U
	V
	W
	X
	Y
Back Cover