The Cognitive Tools of Earth Expansion
| Scientific Paper | |
|---|---|
| Title | The Cognitive Tools of Earth Expansion |
| Read in full | Link to paper |
| Author(s) | Stavros T Tassos |
| Keywords | earth expansion, quantum mechanics |
| Published | 1998 |
| Journal | New Concepts in Global Tectonics Newsletter |
| Volume | Nov. 1998 |
| No. of pages | 15 |
| Pages | 188-193 |
Read the full paper here
Abstract
Questions to answer:
* Is the dominant character of processes inside the Earth reversible or irreversible?
- If irreversibility dominates, is it degrading or upgrading?
- If upgrading, is it a result of one major catastrophic event that happened very early in Earth’s history, or is it an ongoing process and a result of many episodes?
- Is the Earth a Heat Engine (Gravity mechanics) or a Stress Engine(Quantum mechanics)?
Overview
Presented at the International Symposium on New Concepts in Global Tectonics in November 1998, this paper by Stavros Tassos of the Institute of Geodynamics at the National Observatory of Athens is not a conventional argument but an assembled toolkit. Tassos poses four questions about the Earth's interior, then lays out — in list form, as compressed statements of physical and geological fact with their numbers attached — the "cognitive tools" he considers necessary to answer them. Only at the very end does he give the answers.
The framing question is the decisive one: is the Earth a Heat Engine, driven by gravity mechanics, or a Stress Engine, driven by quantum mechanics? Mainstream geodynamics takes the first: the interior is hot, heat escapes by convection, and gravitational settling plus radiogenic heating supply the energy that drives plate motions. Tassos argues for the second, and his conclusion is stated in a single sentence: the Earth, except for a thin surface layer, is "an electrically unbalanced 'real gas' of particles subject to the exclusion principle." His philosophical premise is declared at the outset — "A knowable material reality with necessities, but also with possibilities and potentialities, exists independent of human thought and action."
The argument
Irreversibility
Tassos begins with thermodynamics, and the choice is deliberate: reversibility requires thermal equilibrium, conservative forces only, independent particles as in ideal or very dilute gases, and no heat loss. Irreversibility follows from the opposite conditions — lack of thermal equilibrium, non-conservative forces such as friction, interacting particles as in real gases and fluids, and lack of insulation. Since the Earth is a thermally open system, complete reversibility is impossible; complete conversion of thermal energy into mechanical work cannot occur "unless there is a constant input of thermal energy."
He then makes the move on which the whole paper turns. Entropy in a crystal is S = klnW, with W the number of available lattice arrangements or degrees of freedom. The higher the pressure, the more restricted the mobility of atoms, the fewer the degrees of freedom, and therefore the lower the entropy. Pressure, not temperature, becomes the organising variable — and increasing order under increasing pressure is what he means by irreversibility that is upgrading rather than degrading.
Why heat cannot be the driver
The supporting numbers are all comparisons of scale. Thermal energy — the sum of translational, rotational and vibrational energy — is only a very small fraction of electronic energy. Binding energy between atoms is of order electron-volts, while between nucleons it is of order MeV, about 106 times greater; iron has the highest nuclear binding energy at 8.8 MeV per nucleon. The gravitational force between a proton and an electron is about 4×10−47 N against an electric force of about 9×10−8 N, some 1039 times greater — and the electric force, he notes, "is behind friction and other contact forces." Van der Waals forces between dipoles and confining walls are about 1036 times stronger than gravity and "can move the polar atoms against gravity."
Under high pressure, translation, rotation and vibration of atoms become negligible, the heat capacity of the system is very low, and what remains available is the electronic level: compression of electron shells, flow of electrons, high electrical conductivity. Tunnelling through a potential barrier can be achieved by heating to 106–109 degrees, or by lowering the barrier with an external electric potential, or by narrowing it to 10−8–10−9 m through pressure. Fusion of hydrogen nuclei, he states, requires a pressure of order 1026 Pa; a proton travelling at about 3×107 m/s produces shock-wave pressures of order 1030 Pa, since shock waves form wherever wave sources move faster than the waves they produce and the cone sharpens toward a line as speed rises. He gives the reaction chain 22H + 2p → 23He + 2γ + 11 MeV → 4He + 2p + γ + 13 MeV, yielding two protons and 24 MeV.
Quantum tools
A long central section assembles quantum mechanics: angular momentum with the dimensions of action, Planck's constant h = 6.63×10−34 J·s, the four quantum numbers, the Uncertainty Principle, and the boson/fermion distinction. The pieces he actually needs are these. Identical bosons congregate in the lowest available energy state, which explains lasers and superfluidity. Pairs of identical fermions can form bosons and behave as one large boson system, which is the microscopic explanation of superconductivity — pairing that occurs "when ion lattices can not vibrate, as a result of low temperature and/or high pressure." The zero spin state, from attraction between antiparallel spins, is a low energy state; the unit spin state, from repulsion between parallel spins, is high. Incompressibility results from repulsive forces between identical fermions, compressibility from attraction between identical bosons.
Two opposed pressures are then defined: the outward electron degeneracy pressure Pe = (3/5)[(h/2π)2/2me][(3π2)2/3][(Ne/V)5/3], and the inward gravitational pressure Pg = 0.32[G(NnMn)2/V4/3]. The core is to be treated as "a real gas of particles, particularly of electrons, protons and α-particles, subject to the exclusion principle", in which the excluded-volume correction is negligible but the pressure-reduction correction from van der Waals clustering is very important, producing considerable contraction.
Tassos also departs from standard classification, listing three fundamental forces: gravity for bulk matter, a "Weak Force" that he takes to include all electromagnetic-type forces at the atomic level, and the Strong Force at the nuclear level.
Geological and geophysical tools
The second half is a compilation of terrestrial numbers, and several are chosen to embarrass the heat-engine picture. Oceanic crust covers 60–65% of the surface and is mafic and younger than 200 million years; continental crust covers 35–40% and reaches 4 billion years. Rocks of the Moon, Mars, Mercury and meteorites resemble continental crust — iron-poor and about 4 billion years old — while iron-rich rocks are scarce and much older than 200 million years. The northern hemisphere stands about 2.5 km higher than the southern, giving it a moment of inertia greater by 0.03% and a westward lag he names the Tethyan Torsion.
Geothermal heat loss is given as of order 3×1013 W, with heat flow of 1.5–2 μcal/s/cm2 or 60–80 mW/m2. Concentrations of 232Th and 238U are 65 and 18 ppb, and almost all radioactive elements are concentrated in the upper few kilometres of continental crust — with the Moon about three times richer than the Earth. The point is that the radiogenic budget is both small and in the wrong place to drive the interior.
The electrical inventory is the paper's most distinctive content. The surface electric field is about −102 V/m; the potential difference between surface and mantle–core boundary is put at 290×106 V. He then assumes a field of order −1031 V/m at the mantle–outer core surface, corresponding to about 1053 electrons, and +1029 V/m at the outer–inner core boundary, corresponding to about 1050 protons in the inner core, with a potential difference between them of order 2×1037 V. Estimated conductivity rises from ~10−2 at the surface through ~1 in young oceans to ~102 (ohm·m)−1 at the core–mantle boundary. An electron moving at 107 m/s near the inner core, where those 1050 protons sit, is said to generate a magnetic flux density of order 1021 tesla.
Rheology closes the list. Above about 0.5 GPa and 770 K — depths beyond ~20 km — no brittle deformation occurs. Strain rates inside the Earth are of order 10−15 s−1, about 107 times slower than the slowest attainable in experiments. Tensile strength of mantle rock is of order 1010 Pa against 106 Pa for granite at the surface; viscosity ranges from 1020 to 1027 poise and relaxation times from 109 to 1015 s. In a Stress Engine Earth the mantle behaves as a plastic-brittle material; in a Heat Engine Earth, as a dilatant-ductile one. Tassos ends the compilation with a pointed asymmetry: seismic velocities, density and pressure with depth are known "with a degree of confidence of 95%", whereas the variation of temperature with depth, below about 10 km, "is not directly known."
Answers
The processes inside the Earth are irreversible; the irreversibility is upgrading; the upgrading is the result of many episodes rather than one early catastrophe; and the Earth is a Stress Engine — an electrically unbalanced real gas of particles subject to the exclusion principle. Expansion, in this picture, follows from matter being generated and de-densified under falling pressure as the interior works its way outward, rather than from any thermal engine.
Assessment
The paper's strongest move is methodological, and it is a good one. By ending on the observation that the depth profiles of velocity, density and pressure are measured while the temperature profile is not, Tassos identifies a genuine soft spot: the geotherm below the shallow crust is inferred from assumed adiabats, phase-transition depths and models of core composition, not measured, and a great deal of standard geodynamics rests on it. His insistence on comparing energy scales before assigning a driver is also sound practice, and the point that electronic and nuclear energies dwarf thermal energies is correct as stated. The emphasis on pressure as a variable that reduces entropy is a real and under-used idea, and the observation that superconducting-type pairing can be produced by high pressure as well as by low temperature is legitimate physics. As a reading list with numbers attached, the compilation is useful in itself.
But the form is also the problem. This is a list, not an argument. Between the physics tools and the geological tools there is no derivation — no calculation in which the quantum quantities are applied to a specific volume of the Earth to yield a rate of volume increase, a heat budget, or a stress. The conclusion that the Earth is a Stress Engine does not follow from the assembled facts; it is placed after them. Nothing in the paper computes how much expansion the proposed mechanism would produce, over what time, or what would be observed if it were wrong.
The electrical figures are where this shows most sharply, and they cannot be right. A field of 1031 V/m is roughly 1013 times the Schwinger limit at which the vacuum breaks down into electron–positron pairs; the energy density of such a field alone would exceed the mass-energy of the Earth by an enormous factor. A net charge of 1053 electrons is about 1034 coulombs, and the electrostatic self-energy of that charge distributed over a body of Earth's radius exceeds the Earth's gravitational binding energy by tens of orders of magnitude — the planet would disassemble instantly. Similarly, a field of 1021 tesla is some 1013 times the strongest magnetar field known and vastly beyond the quantum critical field; it is also inconsistent with the paper's own figure of about 0.5 gauss at the surface, which no plausible geometry can reconcile with 1021 tesla in the core. These quantities are introduced with the word "assumed", and they are never checked against anything.
Smaller internal inconsistencies point the same way. The ratio of thermal to electronic energy is given as 10−4 to 10−5 on one page and as 10−6 to 10−2 on another. The geothermal heat loss is quoted as "3×1013 W per year", but a watt is already a rate. Hydrogen is said to have the lowest nuclear binding energy at 1.1 MeV per nucleon, which is the figure for deuterium; ordinary hydrogen has none. The three-force taxonomy, folding electromagnetism into the weak force, is not a defensible simplification but a category error, since the two have different couplings, ranges and conservation laws.
The geological argument also leaves the decisive test untouched. The Expanding Earth hypothesis stands or falls on whether the Earth's radius has changed measurably, and that is now directly testable: space-geodetic solutions combining VLBI, SLR and GPS constrain any secular change in mean radius to well under a millimetre per year, far below what expansion tectonics requires. The paper predates the best of those results, so this is not a fault of the author, but it does mean that the compilation's central conclusion has since been confronted by a measurement it does not survive. Likewise, the observation that oceanic crust is young and continental crust old is real and important, but it is exactly what subduction predicts; presenting it as evidence for expansion requires an argument that subduction does not occur, which the paper does not attempt.
Read for what it is — a personal syllabus setting out why one geophysicist thinks the interior should be modelled with quantum rather than gravitational mechanics — the paper has interest, and its scepticism about an unmeasured geotherm is well placed. Read as a case for expansion, the connective tissue is missing and the load-bearing numbers do not survive a dimensional check.