Journal and Proceedings of
The Royal Society of New South Wales
Volume 103 Parts 3 and 4 [Published Dec 1, 1971]
CONTENTS
| AUTHORS & TITLES | PAGES |
| Burman R.. Light Tracks Near a Dense Charged Star | 87-90 |
| Sims, K.P. Occultations Observed at Sydney Observatory during 1970 | 91-92 |
| Hill, D. The Bearing of Some Upper Palaeozoic Reefs and Coral Faunas on the Hypothesis of Continental Drift [Clarke Memorial Lecture for 1971] |
93-102 | Wellman, P., Cundari, A. and MacDougall, Ian. Potassium-Argon Ages for Leucite-Bearing Rocks from New South Wales, Australia | 103-107 |
| Cavill, G.W.K. Chemistry of Some Insect Secretions [Liversidge Research Lecture for 1970] |
109-118 |
| Taylor N.W. and Marsh, L. McL., Relativistic Motion in Two Space-like Dimensions | 119-122 |
| Prokhovnik, J. The Nature of Time and Its Measurement | 123-126 |
vol. 103 pts 3-4, pp.87-90
Light Tracks Near a Dense Charged Star
R. Burman
Abstract. Integrals of the Einstein-Maxwell equations for static spherically symmetric situations in regions outside matter, with one of the functions in the metric left arbitrary are used to investigate light tracks in the presence of a charged body. Conditions for the existence of circular photon orbits are obtained and non-circular paths are discussed.
vol. 103 pts 3-4, pp.91-92
Occultations Observed at Sydney Observatory during 1970
K.P. Sims
[No Abstract]
vol. 103 pts 3-4, pp.93-102
The Bearing of Some Upper Palaeozoic Reefs and Coral Faunas on the Hypothesis of Continental Drift
D. Hill
[Clarke Memorial Lecture for 1971]
Extract from Opening Paragraphs
...
Interest in the hypothesis of continental drift has been enormously increased in recent years by geophysical observation and speculation. Palaeomagnetic and seismological observations, deductions and assumptions have led to the concept of "plate tectonics", which postulates physical conditions in the earth's crust and mantle such that very considerable movement of large or small segments of the earth's crust is possible. Segments that are relatively stable within themsleves, such as the continents, are thus assumed to have moved relative to one another.
The critical evaluation of their evidence, their assumptions and deductions is best left to the geophysicists themselves. Geologists, have a part to play, however, in looking to the tests their own accumulations of data may apply to the hypothesis
Reefs and coral faunas are of use in testing the hypothesis of continental drift only in so far as they may be taken as indicators of palaeoclimates and palaeoclimatic zones.
The reef provinces of today are all located in the shallow sunlit waters of the tropics and near tropics. Reef growth in waters of average annual minimum temperature of less than 15°C. is greatly restricted or minimal, and so the present reef provinces tend to be bounded by this isotherm. Whether past shallow water reef growth was controlled by this temperature we still have to establish. Temperature is vital to our argument. If we can assume that the reef provinces of past eras were similarly located, we may use the known distribution of fossil reef provinces to deduce the position of tropical (and near-tropical) zones in past times. We may thus drawy lines across the continents limiting the tropical zones of each geological age. It should then become apparent whether the continents have or have not always occupied their present position relative to the equator. If they have not, the lines will have an angular relation to the present equator, and this angle will vary from continent to continent according to the degree to which each continent has drifted.
vol. 103 pts 3-4, pp.103-107
Potassium-Argon Ages for Leucite-Bearing Rocks from New South Wales, Australia
P. Wellman, A Cundari and Ian MacDougall
Abstract. The central New South Wales leucitites have Miocene K-Ar ages (14-10 m.y.) that overlap with the ages of the eastern New South Wales volcanic rocks. The Murrumburrah leucite has a minimum K-Ar age of Early Jurassic.
vol. 103 pts 3-4, pp. 109-118
Chemistry of Some Insect Secretions
G. W. K. Cavill
[Liversidge Research Lecture, 22nd October, 1970]
Introduction. A number of the secretions used by insects and other arthropods for defensive purposes, as venoms, and as chemical messengers in their patterns of social organization have been characterized. These secretions are produced by exocrine, that is ducted glands, which commonly open to the exterior, and vary in number, complexity and 1ocation. ...
Generally, defensive secretions are used by insects to prevent or discourage their enemies from interfering in their life patterns. The venoms, communicated by biting or stinging, are used to kill or incapacitate the prey forming food for the insect or its young. The exocrine secretions used as chemical messengers are termed pheromones. They convey signals between individuals of the same or closely related species concerning, for example, food sources, mating or the presence of enemies. The broad categories — defensive secretions, venoms, pheromones — are not mutually exclusive, and a given secretion may have more than one function. The pheromones, as products of ducted endocrine glands, can be distinguished. from hormones, which are products of ductless endocrine glands.
The chemistry of insect secretions has been studied, in detail, essentially in the last two decades. Whilst the work of pioneers such as Butenandt and his colleagues precedes this period, their structural studies on the sex pheromone, and the moulting hormone of Bombyx mori were not brought to fruition until the 1960's. The earliest report of a chemical investigation on an insect secretion would appear to be one by the English botanist John Wray, who noted in 1670 that Samuel Fisher had obtained an acid, formic, by dry distillation of wood ants. The chemical characterization of formic acid was undertaken by Berzelius and Liebig early in the nineteenth century. A number of biological observations on odoriferous insect secretions — some fragrant and others repugnant — have since been noted, but these observations do not appear to have been fol1owed up to any great extent by the chemist interested in natural products. Whilst the structure of cantharidin was investigated at the beginning of the twentieth century, this work does not appear to have been directed per se to an understanding of insect secretions.
In the present lecture emphasis is placed on aspects of the chemistry of insect secretions that have interested us since 1952.
vol. 103 pts 3-4, pp. 119-122
Relativistic Motion in Two Space-like Dimensions
N. W. Taylor and L. McL. Marsh
Abstract. In relativity theory a set of co-ordinate transformations suitable for investigating conditions experienced directly by an accelerated observer can be found. These transformations simplify the discussion of topics such as uniform rotation and the Thomas precession.
vol. 103 pts 3-4, pp.123-126
The Nature of Time and Its Measurement
S. J. Prokhovnik
Abstract. Einstein's new approach to space and time stimulated a complete re-evaluation of these concepts. In particular, his notion of time-dilatation, with its promise of journeys into the future (and also into the past?), stirred the imagination of philosophers and writers of fiction. In the wake of Minkowski, time became merely a fourth dimension and scientists are still arguing about the "arrow of time" and the possibility of its reversal.
It is suggested that neither Special Relativity (nor any other physica1 theory) provides support to most of these speculations, Indeed Einstein's approach affirms that time is not an absolute concept apart from nature, but that it is a property of nature and can only be measured in terms of natural processes. Some implications of this viewpoint are outlined, and mention is made of a cosmological interpretation of the Special Theory which provides a universal measure of time through the concept of "cosmic time ".