Post by Admin on Jul 28, 2021 23:16:53 GMT -7
Planetary Evolution
The primary source of all free energy in the universe is the original gravitational potential of matter when it appeared, evenly-spread, in the very early universe due to the decay of the earlier, unstable ‘false vacuum’ (Lineweaver and Egan, 2008).
The second law of thermodynamics, when reinterpreted as a principle of maximum entropy production, stipulates that physical systems will tend to degrade gradients, and to develop systems to degrade them (and thus increase entropy, or disorder) more quickly (Dewar et al., 2014). However, as systems evolve there is typically a dialectic between mixing (the destruction of difference and gradients) and sorting (and thus the creation of new gradients).
In the case of the early universe it was the gravitational clumping of matter that allowed the emergence of non-equilibrium, producing ‘dissipative structures’ such as galaxies, solar systems and eventually planets (Lineweaver and Egan, 2008). As part of the onward rush towards overall disorder and entropy, these dissipative structures (Prigogine and Stengers, 1984) create local order (highly correlated states) and new gradients, thus greater complexity and informational order, including new kinds of motion.
The result at the scale of solar systems and planets is patterns that are specific and irreversible; planets are not just mixtures of different chemicals and states of matter, but have unique, divergent and emergent histories (DeLanda, 1992). We can see this in the diversity of planets in our own system, let alone those in extrasolar
planetary systems.
The Earth thus has to be seen as a body which emerged, evolved and continues to evolve in an ongoing dialectic between the intensive (differences and gradients) and the extensive (form and structure). Even before the formation of Earth, the accretion of the solar system from the solar nebula was already a great sorting which occurred through complex forms of mobility.
A key ‘saddle point’ dividing the mobility regions of any solar system is the ‘frost line’, beyond which solar heat is weak enough for volatiles such as water, carbon monoxide and methane to freeze. This is line is positioned differently for different volatiles and around different stars, but in our own solar system is at approximately 5 astronomical units (AU) from the sun – just outside the asteroid belt (1AU is the distance from the Sun to the Earth) (Prockter, 2005). The eventual effect of this was to produce a complex but ordered planetary system with gas and ice giants outside the frost line and small rocky planets within.
Inside the frost line, volatiles evaporate and smaller ‘terrestrial’ planets accrete from metals and heavier atoms; outside the frost line, giant planets form due to the greater number of solid particles and their ability to retain greater amounts of light gases (ibid.). From a planetary mobilities perspective this is also a sorting of powers of mobility: the creation of bodies which have different powers to move things around within themselves.
Planets, by definition, come to dominate their area of the solar system – and sometimes move to new stable orbits so they can do so (Soter, 2006). Isolated in the vacuum, planetary bodies follow the ellipses, parabolas and hyperbolas of gravitational motion, guided by the absolute memory of reversible Newtonian mechanics.
Within themselves, however, their gravitational collapse into planetary bodies will produce energy gradients and far-from equilibrium conditions which favour the emergence of local order. Planets are bodies where the combination of fluid motion and solid durability creates information-rich pockets, where correlated states and motions such as those described in the last section can arise, endure and become more elaborate (Hidalgo, 2015).
Astronomers talk about the ‘Goldilocks’ or ‘habitable’ zone around stars which enjoys the temperatures enabling the emergence of water-based life; but such zones are just one of the many self-organising ‘mobility regions’ in which planets can acquire different powers of internal motion.
For planets and other astral bodies to ‘learn’ in this way – to have a unique and irreversible history of emergence – they need new ways of recording, recalling, learning and forgetting past mobilities.
As Prigogine and Stengers put it, classical dynamic systems such as those governing planetary motion in what the ancients called the ‘superlunary’ world of the heavens already know everything they need to know in order to move along their orbits, and can never forget it (Prigogine and Stengers, 1984, pp. 305–6).
But in the sublunary, far-from-equilibrium world of planetary becoming, what are needed for new mobility powers to develop are interacting systems of non-Newtonian memory: fluid memory (residing in the motion of flows, eddies or vortices), solid memory (in the stratigraphy, geodiversity and surface morphology of the solid earth, and in complex objects) and code memory (in DNA, culture with its arbitrary symbols or computational machines). If information is important for planetary mobilities, no less so is energy.
Energy as defined by modern science cannot be created or destroyed, but it can be higher or lower in quality, as defined by its availability to do ‘work’ – in effect, to move macroscopic objects or create macroscopic gradients. Chemical, electrical and mechanical energy are all forms of high-grade energy in this sense, whereas heat energy, the random motion of atoms and molecules, is low-grade energy. However, the amount of work that can actually be done by the energy in any system (for example a pressurised container) depends on the difference between the energetic levels of that system and those of its environment. This difference is termed ‘exergy’, the amount of energy that is available to do work in relation to a suitable reference state, and this decreases as entropy increases.
In the solar system, the primary reservoirs of exergy are the nuclear energy from fusible atoms in the sun and fissionable atoms in planetary bodies,
the gravitational and kinetic energy of the solar system, and the residual thermal energy remaining from its formation (Hermann, 2006, p. 1689). From these primary reservoirs, energy cascades into secondary reservoirs, a cascade which within planets is conditioned by their particular history of self-organisation. The outer planets – the gas giants Jupiter, Saturn and ice giants Uranus and Neptune – are so far from the sun that they receive little energy from it; instead, the motion of their atmospheres is driven mainly by the residual internal heat from compression and friction.
Despite their coldness, the availability of different chemical elements with different melting points allows the outer planets and their moons to have rocks, atmospheres, seas and hydrological cycles, just based on different chemistry. Their residual inner heat is also sufficient to sustain vertical temperature gradients that ensure that even the extremely cold atmosphere of Neptune, which only receives 1/900th of the solar energy per unit area that the Earth does, and is 55 K or −218°C at its cloud tops, nevertheless has the most violent weather in the solar system (Suomi et al., 1991).
The huge gravity wells of the outer planets also allow them to form highly complex satellite systems, with rings, shepherd moons that maintain ring boundaries and co-orbital moons that swap orbits (Spitale et al., 2006). As we explore the outer planets we are likely to find more and more unique mobility patterns in and around them.
Planets such as the Earth that formed and move within the frost line are very different. The higher temperatures closer to the sun do not mean more liquids and gases; instead, the greater power of the solar flux and solar wind strips volatiles away, making the inner planets smaller and more predominantly solid.
Inside the inner planets lies a world that is almost as cut off from the sun as the outer solar system. The insulating power of Earth’s silicate rocks means that seasonal changes in heat from the sun are not felt below a depth of 10-20m; from here downwards, the Earth is shaped by its own powers, especially the heat generated by its initial gravitational collapse, friction and nuclear decay.
The slow but powerful convection of the magma shapes the surface above it, slowly releasing heat from the interior and ensuring that the Earth does not, like Venus, periodically turn itself inside out, a cataclysmic forgetting which destroys the old surface and everything on it (Zalasiewicz, 2008, pp. 49-50).
But on and above the solid surface of the inner planets, the sun rules. The surface of the Earth, for example, receives nearly 2,000 times more energy from the sun than it does from the planet’s interior (Davies and Davies, 2010).
The inner planets are thus subject to a constant excess of electro-magnetic energy, and one which is unevenly spread across their spherical surfaces. Energy leaving the Earth system has to be equal to that arriving in it for its average temperature to remain relatively constant. But the majority of incoming solar energy works its way through the Earth system before it is converted to heat and radiated back out. Apart from the tidal movements caused by gravity, the major fluid motion on the earth – of the winds, the ocean and the wider water cycle – is driven by this solar energy, as radiative gradients produce temperature gradients, themselves producing pressure and density gradients, and thus motion (Kleidon, 2010).
In the next section we will look at this fluid mobility
The primary source of all free energy in the universe is the original gravitational potential of matter when it appeared, evenly-spread, in the very early universe due to the decay of the earlier, unstable ‘false vacuum’ (Lineweaver and Egan, 2008).
The second law of thermodynamics, when reinterpreted as a principle of maximum entropy production, stipulates that physical systems will tend to degrade gradients, and to develop systems to degrade them (and thus increase entropy, or disorder) more quickly (Dewar et al., 2014). However, as systems evolve there is typically a dialectic between mixing (the destruction of difference and gradients) and sorting (and thus the creation of new gradients).
In the case of the early universe it was the gravitational clumping of matter that allowed the emergence of non-equilibrium, producing ‘dissipative structures’ such as galaxies, solar systems and eventually planets (Lineweaver and Egan, 2008). As part of the onward rush towards overall disorder and entropy, these dissipative structures (Prigogine and Stengers, 1984) create local order (highly correlated states) and new gradients, thus greater complexity and informational order, including new kinds of motion.
The result at the scale of solar systems and planets is patterns that are specific and irreversible; planets are not just mixtures of different chemicals and states of matter, but have unique, divergent and emergent histories (DeLanda, 1992). We can see this in the diversity of planets in our own system, let alone those in extrasolar
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planetary systems.
The Earth thus has to be seen as a body which emerged, evolved and continues to evolve in an ongoing dialectic between the intensive (differences and gradients) and the extensive (form and structure). Even before the formation of Earth, the accretion of the solar system from the solar nebula was already a great sorting which occurred through complex forms of mobility.
A key ‘saddle point’ dividing the mobility regions of any solar system is the ‘frost line’, beyond which solar heat is weak enough for volatiles such as water, carbon monoxide and methane to freeze. This is line is positioned differently for different volatiles and around different stars, but in our own solar system is at approximately 5 astronomical units (AU) from the sun – just outside the asteroid belt (1AU is the distance from the Sun to the Earth) (Prockter, 2005). The eventual effect of this was to produce a complex but ordered planetary system with gas and ice giants outside the frost line and small rocky planets within.
Inside the frost line, volatiles evaporate and smaller ‘terrestrial’ planets accrete from metals and heavier atoms; outside the frost line, giant planets form due to the greater number of solid particles and their ability to retain greater amounts of light gases (ibid.). From a planetary mobilities perspective this is also a sorting of powers of mobility: the creation of bodies which have different powers to move things around within themselves.
Planets, by definition, come to dominate their area of the solar system – and sometimes move to new stable orbits so they can do so (Soter, 2006). Isolated in the vacuum, planetary bodies follow the ellipses, parabolas and hyperbolas of gravitational motion, guided by the absolute memory of reversible Newtonian mechanics.
Within themselves, however, their gravitational collapse into planetary bodies will produce energy gradients and far-from equilibrium conditions which favour the emergence of local order. Planets are bodies where the combination of fluid motion and solid durability creates information-rich pockets, where correlated states and motions such as those described in the last section can arise, endure and become more elaborate (Hidalgo, 2015).
Astronomers talk about the ‘Goldilocks’ or ‘habitable’ zone around stars which enjoys the temperatures enabling the emergence of water-based life; but such zones are just one of the many self-organising ‘mobility regions’ in which planets can acquire different powers of internal motion.
For planets and other astral bodies to ‘learn’ in this way – to have a unique and irreversible history of emergence – they need new ways of recording, recalling, learning and forgetting past mobilities.
As Prigogine and Stengers put it, classical dynamic systems such as those governing planetary motion in what the ancients called the ‘superlunary’ world of the heavens already know everything they need to know in order to move along their orbits, and can never forget it (Prigogine and Stengers, 1984, pp. 305–6).
But in the sublunary, far-from-equilibrium world of planetary becoming, what are needed for new mobility powers to develop are interacting systems of non-Newtonian memory: fluid memory (residing in the motion of flows, eddies or vortices), solid memory (in the stratigraphy, geodiversity and surface morphology of the solid earth, and in complex objects) and code memory (in DNA, culture with its arbitrary symbols or computational machines). If information is important for planetary mobilities, no less so is energy.
Energy as defined by modern science cannot be created or destroyed, but it can be higher or lower in quality, as defined by its availability to do ‘work’ – in effect, to move macroscopic objects or create macroscopic gradients. Chemical, electrical and mechanical energy are all forms of high-grade energy in this sense, whereas heat energy, the random motion of atoms and molecules, is low-grade energy. However, the amount of work that can actually be done by the energy in any system (for example a pressurised container) depends on the difference between the energetic levels of that system and those of its environment. This difference is termed ‘exergy’, the amount of energy that is available to do work in relation to a suitable reference state, and this decreases as entropy increases.
In the solar system, the primary reservoirs of exergy are the nuclear energy from fusible atoms in the sun and fissionable atoms in planetary bodies,
6
the gravitational and kinetic energy of the solar system, and the residual thermal energy remaining from its formation (Hermann, 2006, p. 1689). From these primary reservoirs, energy cascades into secondary reservoirs, a cascade which within planets is conditioned by their particular history of self-organisation. The outer planets – the gas giants Jupiter, Saturn and ice giants Uranus and Neptune – are so far from the sun that they receive little energy from it; instead, the motion of their atmospheres is driven mainly by the residual internal heat from compression and friction.
Despite their coldness, the availability of different chemical elements with different melting points allows the outer planets and their moons to have rocks, atmospheres, seas and hydrological cycles, just based on different chemistry. Their residual inner heat is also sufficient to sustain vertical temperature gradients that ensure that even the extremely cold atmosphere of Neptune, which only receives 1/900th of the solar energy per unit area that the Earth does, and is 55 K or −218°C at its cloud tops, nevertheless has the most violent weather in the solar system (Suomi et al., 1991).
The huge gravity wells of the outer planets also allow them to form highly complex satellite systems, with rings, shepherd moons that maintain ring boundaries and co-orbital moons that swap orbits (Spitale et al., 2006). As we explore the outer planets we are likely to find more and more unique mobility patterns in and around them.
Planets such as the Earth that formed and move within the frost line are very different. The higher temperatures closer to the sun do not mean more liquids and gases; instead, the greater power of the solar flux and solar wind strips volatiles away, making the inner planets smaller and more predominantly solid.
Inside the inner planets lies a world that is almost as cut off from the sun as the outer solar system. The insulating power of Earth’s silicate rocks means that seasonal changes in heat from the sun are not felt below a depth of 10-20m; from here downwards, the Earth is shaped by its own powers, especially the heat generated by its initial gravitational collapse, friction and nuclear decay.
The slow but powerful convection of the magma shapes the surface above it, slowly releasing heat from the interior and ensuring that the Earth does not, like Venus, periodically turn itself inside out, a cataclysmic forgetting which destroys the old surface and everything on it (Zalasiewicz, 2008, pp. 49-50).
But on and above the solid surface of the inner planets, the sun rules. The surface of the Earth, for example, receives nearly 2,000 times more energy from the sun than it does from the planet’s interior (Davies and Davies, 2010).
The inner planets are thus subject to a constant excess of electro-magnetic energy, and one which is unevenly spread across their spherical surfaces. Energy leaving the Earth system has to be equal to that arriving in it for its average temperature to remain relatively constant. But the majority of incoming solar energy works its way through the Earth system before it is converted to heat and radiated back out. Apart from the tidal movements caused by gravity, the major fluid motion on the earth – of the winds, the ocean and the wider water cycle – is driven by this solar energy, as radiative gradients produce temperature gradients, themselves producing pressure and density gradients, and thus motion (Kleidon, 2010).
In the next section we will look at this fluid mobility