ALBERT

Notes: Abstract The earth with all its inhabitants, including man, has had a long history as a slowly evolving complex system which normally exists in a state of stable dynamic equilibrium. Explosive growth in the human population, in the per capita use of nonrenewable resources, and in the degree of human disruption of established ecosystems — the hallmark of man's recent and rapid emergence as the dominant species on the face of the earth — represents a major departure from this state of equilibrium and an ecological crisis of global dimensions. This growth, and the rapid changes that arise from it, have had such a pervasive influence on the collective experience of man that they have come to be regarded as the normal course of events on a stable earth. This has fostered the notion that growth will always be essential for further improvements in the quality of human life. The emergence of a global technological civilization results from man's ingenuity in devising ways of using an ever increasing proportion of energy available at the earth's surface. Rapid growth began only two hundred years ago when the developing technology of the industrial revolution made possible the large-scale exploitation of the earth's fossil-fuel resources and the creation of positive feedback between growth in technology and growth in fossil-fuel production. Annual growth rates in world production of fossil fuels and ores of representative industrial metals, when compared with the nature and finite magnitude of the earth's resources, lead to the inescapable conclusion that the present episode of exponential growth can only be a transitory epoch of a few centuries duration within the totality of human history. Solar radiation offers the prospect of large supplies of energy with minimal environmental impact. However, constraints on growth due to the finite nature of food and mineral resources and the effects of environmental degradation can only be loosened in this way, not removed. Mankind faces an inevitable transition from a brief interlude of exponential growth to a stable condition characterized by rates of growth so slow as to be regarded essentially as a state of no growth. Failure to respond rationally and promptly to this situation could be disastrous.

Notes: Abstract In this paper, we apply the ideas presented by one of us (Prentice, 1978a, b) for the development of the proto-solar cloud into a system of Laplacian rings to the development of the protoplanetary clouds which ultimately led to Jupiter, Saturn and Uranus. We show that if one accepts this scenario — especially the idea of supersonic turbulence in the proto-planetary clouds — one can satisfactorily explain, on the basis of fixing a single adjustable parameter, both the geometric precession of the orbital radii of the regular satellite systems of these three planets and the chemical composition and mass distribution of these satellites. We suggest that thermal stirring in the proto-planetary cloud in the vicinity of the surface of the planet may be responsible for the smaller masses of some of the inner satellites as well as for the formation of the rocky rings of Uranus. The icy rings of Saturn are suggested to be the product of condensation processes in a continuous gaseous disc within the Roche limit of the planet.

Notes: [Auszug] The regular satellite systems of Jupiter, Saturn and Uranus are remarkable for the near coplanarity and circularity of their orbits. In addition, the orbital radii Rn, when numbered from the outermost members inwards (n = 0, 1, 2,...), form nearly perfect geometric sequences R R(1) where for ...

Notes: [Auszug] Soluble complexes can be produced by an intravenous infusion of thrombin in rabbits2. Although such experiments are not possible in man, the use of thrombin-like snake venoms as defibrinating agents could provide a valuable alternative. Soluble complexes have been identified in the plasma of ...

Notes: Abstract A theory for the origin of the solar system, which is based on ideas of supersonic turbulent convection and indicates the possibility that the original Laplacian hypothesis may by valid, is presented. We suggest that the first stage of the Sun's formation consisted of the condensation of CNO ices (i.e. H2O, NH3, CH4,...) and later H2, including He as impurity atoms, at interstellar densities to from a cloud of solid grains. These grains then migrate under gravity to their common centre of mass giving up almost two orders of magnitude of angular momentum through resistive interaction with residual gases which are tied, via the ions, to the interstellar magnetic field. Grains rich in CNO rapidly dominate the centre of the cloud at this stage, both giving up almost all of their angular momentum and forming a central chemical inhomogeneity which may account for the present low solar neutrino flux (Prentice, 1976). The rest of the grain cloud, when sufficiently compressed to sweep up the residual gases and go into free fall, is not threatened by rotational disruption until its mean size has shrunk to about the orbit of Neptune. When the central opacity rises sufficiently to halt the free collapse at central density near 10−13 g cm−3, corresponding to a mean cloud radius of 104 R ⊙, we find that there is insufficient gravitational energy, for the vaporized cloud to acquire a complete hydrostatic equilibrium, even if a supersonic turbulent stress arising from the motions of convective elements becomes important, as Schatzman (1967) has proposed. Instead we suggest that the inner 3–4% of the cloud mass collapses freely all the way to stellar size to release sufficient energy to stabilize the rest of the infalling cloud. Our model of the early solar nebula thus consists of a small dense quasi-stellar core surrounded by a vast tenuous but opaque turbulent convective envelope. Following an earlier paper (Prentice, 1973) we show how the supersonic turbulent stress $$(\rho _t v_t ^2 ) = \beta \rho GM(r)/r$$ , where β is called the turbulence parameter, ρ is the gas density andM(r) the mass interior to radiusr causes the envelope to become very centrally condensed (i.e. drastically lowers its moment-of-inertia coefficientf) and leads to a very steep density inversion at its photosurface, as well as causing the interior to rotate like a solid body. As the nebula contracts conserving its angular momentum the ratio θ of centrifugal force to gravitational force at the equator steadily increases. In order to maintain pressure equilibrium at its photosurface, material is extruded outwards from the deep interior of the envelope to form a dense belt of non-turbulent gases at the equator which are free of turbulent viscosity. If the turbulence is sufficiently strong, we find that when θ→1 at equatorial radiusR e=R0, corresponding to the orbit of Neptune, the addition of any further mass to the equator causes the envelope to discontinuously withdraw to a new radiusR e〉R0, leaving behind the circular belt of gas at the Kepler orbitR 0. The protosun continues to contract inwards, again rotationally stabilizing itself by extruding fresh material to the equator, and eventually abandoning a second gaseous ring at radiusR 1, and so on. If the collapse occurs homologously the sequence of orbital radiiR n of the system of gaseous Laplacian rings satisfy the geometric progression $$R_n /R_{n + 1} = [1 + m/Mf]^2 = constant, n = 0, 1,2, \ldots ,$$ analogous to the Titius-Bode Law of planetary distances, wherem denotes the mass of the disposed ring andM the remaining mass of the envelope. Choosing a ratio of surface to central temperature for the envelope equal to about 10−3 and adjusting the turbulence parameter β∼~0.1 so thatR n/Rn+1 matches the observed mean ratio of 1.73, we typically findf=0.01 and that the rings of gas each have about the same mass, namely 1000M ⊕ of the solar material. Detailed calculations which take into account non-homologous behaviour resulting from the changing mass fraction of dissociated H2 in the nebula during the collapse do not appreciably disturb this result. This model of the contracting protosun enables us to account for the observed physical structure and mass distribution of the planetary system, as well as the chemistry. In a later Paper II we shall examine in detail the condensation of the planets from the system of gaseous rings.

Notes: Summary During a field course the vegetation of the extensive mire complex on the west side of Malham Tarn was examined. 84 relevés were collected, with 210 taxa in total. This data set has been ‘structured’ by classical phytosociological techniques. It is suggested that it approaches the maximum size of data-set which can be handled in this way, especially if the data are not all collected by one person. Ordination of the quadrats was carried out but gave little insight into the data despite the use of non-centred as well as centred principal components analysis. Numerical classification of the quadrats using minimumvariance cluster analysis was shown to produce a structure interpretable in ecological terms. A classification of the taxa was carried out by the same method and a ‘rearranged’ table was drawn up using the results of the two classifications. A relocation technique was applied at an appropriate cluster level but little was felt to be gained from this. The use of ‘two-way’ minimum-variance cluster analysis for the rapid production of re-arranged tables is recommended for large data-sets. In addition the vegetational units recognised in the data are described and discussed.