Stellar Bodies Research Articles

Magnetic Fields in Stellar Bodies: II. Magnetic Fields in Upper Main Sequence Stars

Magnetic Fields in Stellar Bodies: II. Magnetic Fields in Upper Main Sequence Stars

Notes on the structure of the SMC as observed in 21-cm line radiation from neutral hydrogen

Earlier surveys of the line radiation from neutral hydrogen in the Magellanic Clouds (Kerr, Hindman, and Robinson 1954; Hindman, Kerr, and McGee 1963; Hindman et al. 1963) have shown that the amount of gas associated with these extragalactic bodies is relatively large. The gas appears widespread, surrounding the stellar bodies in a single continuous and very tenuous envelope with a marked bridge in the vicinity of the optical wing of the SMC linking the two main concentrations.

Evidence for the Stellar Origin of Cosmic Rays

Several authors have suggested the possibility that cosmic rays are due to the acceleration of charged particles in the atmospheres of certain stars. Recent observations at radio frequencies have provided some evidence in support of this hypothesis which is reviewed in this paper. The observations have shown that at least part of the radio-frequency radiation from the galaxy is emitted by discrete sources of small angular diameter. Measurements of the intensity of the radiation from these sources, and of the time variations of the intensity, indicate that the sources emit radio waves as if they were at a temperature of more than 1014 deg. K. It is concluded that this intense radiation cannot be caused by the coherent oscillation of a large number of electrons, but must be due to a genuine electron temperature of about 1014 deg. K. (corresponding to a mean electron energy of 1010 electron volts). The existence of this electron temperature indicates that in certain stellar bodies there are mechanisms capable of accelerating particles to cosmic ray energies. A previous theory of the emission of radio waves from the sun is extended to other stellar bodies. It is concluded that a star having a surface magnetic field strength and a peripheral velocity somewhat greater than those which have so far been observed could emit radio waves having the observed intensity. A star of this type could also accelerate charged particles to cosmic ray energies. The small visual brightness of the sources of radio waves suggests that these bodies may be characterized by small visual opacity or small photospheric temperature. It is suggested that the difference between the angular distribution of cosmic rays and of the radio waves from the galaxy is due to the deflection of cosmic ray particles by magnetic fields. In addition to previous theories of a general magnetic field in the galaxy, it is shown that the scattering produced by the magnetic fields of the distributed sources themselves should be sufficient to produce an isotropic distribution of cosmic rays at the earth even though the sources may show a marked concentration near the galactic equator.

On eddington's problem of the expansion of the universe by condensation

1.The discovery of the general receding motion of the spiral nebulae by Hubble lent importance to the Friedmann-Lemaître solution of Einstein’s field equations and it was promptly suggested that our present universe started from a static condition, and owing to certain unknown causes began expanding and has since been doing so continuously. Eddington* pointed out that the static Einstein universe was unstable and so “exploded” (as Eddington put it) in some past age. Eddington suggested that the reason for explosion was the condensation of matter into stellar bodies out of the nebular mass uniformly filling up the Einstein universe. McCrea† and McVittie, working on this idea, proposed a proof showing that for a single condensation the universe would start contracting, but for more condensations start expanding from the equilibrium state. This proof they have recently withdrawn as being erroneous. Meanwhile, Lemaître§ himself enunciated a theorem stating that condensation itself could not cause expansion or contraction, but it was the stagnation of energy (ultimately amounting to condensation) which disturbed the equilibrium and caused the universe to swell up, but McCrea and McVittie showed that his proof was incorrect. Eddington’s problem thus remains where it was when first proposed. In this note we give a proof which shows that condensations, no matter whatever be their number, would start expansion of the Einstein universe.

Societies and Academies

LONDON. Institution of Mining and Metallurgy, October 19 —Mr. H. Livingstone Sulman, president, in the chair.— H. Standish Ball: The economics of tube milling. The investigation, of which this paper is a report, was undertaken by the author at the McGill University, Montreal, for the purpose of determining the most efficient working conditions of the tube-mill on metal-bearing ores. An experimental tube-mill was constructed, with all necessary accessories, and a series of test runs was made under various conditions of feed, moisture, pebble load, and speed, the system adopted being that in each series of tests one of the above factors was varied whilst the others were maintained as constants. Taking the experimental mill as a standard, the result of the tests was to establish certain conditions for each of the four factors mentioned as those most conducive to efficiency; and the author believes that there is a possibility of estimating from the curves obtained from the different tests the probable results that would be derived from running the mill under different conditions. He deduces from this the rather startling theory that in any mill it would be possible by a similar series of tests to obtain the necessary information for running it to the best advantage. Among other results of his experiments he was able to ascertain the duration of time required by a mill to assume a uniform condition following a change of adjustment of its various component factors, and to test the efficiency of the mill during the transition periods. Having ascertained by tests the several conditions under which the mill worked at its best, a trial was made during which the critical factors were all complied with, and the resultant mechanical efficiency was found to show an increase of 14 per cent, above all previous tests, thus seeming to bear out the utility and value of experimental work in determining the proper conditions of working.—Eugene Coste: Fallacies in the theory of the organic origin of petroleum. The author sets out to show that the supporters of the organic theory founded their arguments on erroneous premises, and ignore the obvious facts presented by the petroleum occurrences and deposits, which point to a volcanic origin In proof of his own theory he directs attention to the abundance of hydrocarbon emanations noted in connection with volcanic phenomena, as showing that the sources of carbon, are not confined to the organic kingdom alone. The conclusion at which he arrives is that the constant recurrence of hydrocarbons in volcanic and igneous rocks, in volcanic emanations, in metallic and other veins, in meteorites, in comets and other stellar bodies, clearly demonstrates that petroleums are not organic, as if they were their distribution could not possibly resemble the actual occurrences which are met with. The petroleum deposits are not everywhere associated with rocks of a particular age, but are found in strata of all ages, and only along some of the tectonic disturbances; where there are no such disturbances the strata are barren. These occurrences are therefore, he claims, due to dynamic disturbances accompanied by magmatic emanations from the interior, which must be held to be of solfataric volcanic nature, and unlike anything else known to be to-day in the active process of formation in nature.

On Mr. T. J. J. See's researches concerning the constitution of stellar bodies

On Mr. T. J. J. See's researches concerning the constitution of stellar bodies

XXIII. Geological Time

The author began by making some observations upon astronomical distance, pointing out that as astronomy had been recognised as a science from an early period in the history of civilisation we had nowadays all become more or less familiar with the conception of vast intervals of space. Geology, on the other hand, was a science of very recent growth, and had hardly yet passed through stages of development which had been reached by astronomy 2000 or more years ago. While, therefore, no rational person was prepared to call in question statements regarding the distances of even the nearest of the stellar bodies, there were many who had failed to realise any true conception of what was meant by “geological time”; like those folk who, centuries ago, opposed the statements of astronomers in regard to vast intervals of space, these now dissented from the statements of geologists in regard to equally vast intervals of time. This, of course, was partly due to the fact that many of the data with which the geologist had to deal had not yet reached the stage of exactitude to which astronomical data had attained in the middle ages. Other reasons, obvious to any thoughtful person, also stood in the way. The lecturer then dealt with some of the evidences which lead the geologist to consider that vast, if still indefinite, periods of time are implied in the development of events in the earth9s past history with which it was his special province to deal. He