scholarly journals IV.—The Periodicity of Earthquakes

1901 ◽  
Vol 8 (10) ◽  
pp. 449-452
Author(s):  
R. D. Oldham
Keyword(s):  
Celestial Body ◽  
Seismic Activity ◽  
The Sun ◽  
The Moon

Many are the attempts that have been made to discern some law in the occurrence of earthquakes, and to trace the influence of the sun, the moon, or even of the planets as a cause, if partial, of their origin. Many patient investigators have discovered, or thought they have discovered, periods of fluctuating seismic activity, varying in length from semi-diurnal to annual or even longer, but so conflicting have been their conclusions that little weight can be, or has been, attached to the results of their calculations; and one of the most industrious of all these investigators, the Commandante de Montessus de Ballore, has declared his conviction that no periodicity can be detected, and that the causes of earthquakes are purely terrestrial and in no way affected by any celestial body. Yet, in spite of this, the attempts and the calculations go on, and one of the most recent of these is a discussion by Herr M. Becke of some three hundred earthquakes recorded in the region round Karlsbad between 24th October and 25th November, 1897.

scholarly journals Venus

1986 ◽  
Vol 7 ◽  
pp. 39-45 ◽  
Author(s):  
R. Sagdeev
Keyword(s):  
Foreign Language ◽  
Celestial Body ◽  
Outer Space ◽  
The Sun ◽  
The Moon ◽  
International Astronomical Union ◽  
Scientific Exploration ◽  
Short Notice ◽  
International Astronomical ◽  
The Usa

I feel very honoured at having been asked by the IAU Executive to present Prof. Sagdeev’s invited discourse on Venus in his absence. As has already been mentioned Prof. Sagdeev was summoned to the talks between the USSR and the USA in Geneva as an expert in Space Research. He went there with several very important proposals for future cooperation in scientific exploration of outer space and we all hope that the results of his mission will be beneficial for the development of space astronomy and therefore for the whole astronomical community represented by the International Astronomical Union. I am sure that all present in this room realize that it is not an easy task to present someone else’s lecture especially at such short notice and in a foreign language. Besides, it is my opinion that a talk on Venus – the brightest celestial body in the sky except the moon and the Sun – Venus which always has been the symbol of beauty, love and femininity, that such a talk should surely be given by a man.

scholarly journals XIII. Observations on the nature of the new celestial body discovered by Dr. Olbers, and of the comet which was expected to appear last January in its return from the sun

1807 ◽  
Vol 97 ◽  
pp. 260-266 ◽  
Keyword(s):  
Solar System ◽  
Celestial Body ◽  
Great Distance ◽  
The Other ◽  
The Sun ◽  
The Moon ◽  
Heavenly Body ◽  
Valuable Addition ◽  
Late Discovery ◽  
The One

The late discovery of an additional body belonging to the solar system, by Dr. Olbers, having been communicated to me the 20th of April, an event of such consequence engaged my immediate attention. In the evening of the same day I tried to discover its situation by the information I had obtained of its motion; but the brightness of the moon, which was near the full, and at no great distance from the object for which I looked, would not permit a star of even the 5th magnitude to be seen, and it was not till the 24th that a tolerable view could be obtained of that space of the heavens in which our new wanderer was pursuing its hitherto unknown path. As soon as I found that small stars might be perceived, I made several delineations of certain telescopic constellations, the first of which was as represented in figure 1, and I fixed upon the star A, as most likely, from its expected situation and brightness, to be the one I was looking for. The stars in this figure, as well as in all the other delineations I had made, were carefully examined with several magnifying powers, that in case any one of them should hereafter appear to have been the lately discovered object, I might not lose the opportunity of an early acquaintance with its condition. An observation of the star marked A, in particular, was made with a very distinct magnifying power of 460, and says, that it had nothing in its appearance that differed from what we see in other stars of the same size; indeed Dr. Olbers, by mentioning in the communication which I received, that with such magnifying powers as he could use it was not to be distinguished from a fixed star, had already prepared me to expect the newly discovered heavenly body to be a valuable addition to our increasing catalogue of asteroids.

Modelling Lunar Extremes

2018 ◽  
Vol 3 (2) ◽  
pp. 207-216 ◽  
Author(s):  
David Fisher ◽  
Lionel Sims
Keyword(s):  
High Precision ◽  
Celestial Mechanics ◽  
Computer Modelling ◽  
Landscape Context ◽  
The Sun ◽  
The Moon

Claims first made over half a century ago that certain prehistoric monuments utilised high-precision alignments on the horizon risings and settings of the Sun and the Moon have recently resurfaced. While archaeoastronomy early on retreated from these claims, as a way to preserve the discipline in an academic boundary dispute, it did so without a rigorous examination of Thom’s concept of a “lunar standstill”. Gough’s uncritical resurrection of Thom’s usage of the term provides a long-overdue opportunity for the discipline to correct this slippage. Gough (2013), in keeping with Thom (1971), claims that certain standing stones and short stone rows point to distant horizon features which allow high-precision alignments on the risings and settings of the Sun and the Moon dating from about 1700 BC. To assist archaeoastronomy in breaking out of its interpretive rut and from “going round in circles” (Ruggles 2011), this paper evaluates the validity of this claim. Through computer modelling, the celestial mechanics of horizon alignments are here explored in their landscape context with a view to testing the very possibility of high-precision alignments to the lunar extremes. It is found that, due to the motion of the Moon on the horizon, only low-precision alignments are feasible, which would seem to indicate that the properties of lunar standstills could not have included high-precision markers for prehistoric megalith builders.

Automated Determination of the Position of Ships by Satellites

1967 ◽  
Vol 20 (03) ◽  
pp. 281-285
Author(s):  
H. C. Freiesleben
Keyword(s):  
Celestial Body ◽  
World Wide ◽  
Artificial Satellites ◽  
Radio Waves ◽  
The Moon ◽  
Position Determination ◽  
The Earth ◽  
Navigational Aids ◽  
Automated Determination

It has recently been suggested that 24-hour satellites might be used as navigational aids. To what category of position determination aids should these be assigned ? Is a satellite of this kind as it were a landmark, because, at least in theory, it remains fixed over the same point on the Earth's surface, in which case it should be classified under land-based navigation aids ? Is it a celestial body, although only one tenth as far from the Earth as the Moon ? If so, it is an astronomical navigation aid. Or is it a radio aid ? After all, its use for position determination depends on radio waves. In this paper I shall favour this last view. For automation is most feasible when an object of observation can be manipulated. This is easiest with radio aids, but it is, of course, impossible with natural stars.At present artificial satellites have the advantage over all other radio aids of world-wide coverage.

Sweat of the Sun and Tears of the Moon. Gold and Silver in Pre-Columbian Art

1967 ◽  
Vol 71 (2) ◽  
pp. 215
Author(s):  
Earle R. Caley ◽  
Andre Emmerich
Keyword(s):  
The Sun ◽  
The Moon

scholarly journals How dim is dim? Precision of the celestial compass in moonlight and sunlight

2011 ◽  
Vol 366 (1565) ◽  
pp. 697-702 ◽  
Author(s):  
M. Dacke ◽  
M. J. Byrne ◽  
E. Baird ◽  
C. H. Scholtz ◽  
E. J. Warrant
Keyword(s):  
Dung Beetle ◽  
The Sun ◽  
The Moon ◽  
Polarization Pattern ◽  
Animal Group ◽  
Straight Line ◽  
Celestial Orientation ◽  
Polarization Compass ◽  
Celestial Compass ◽  
Diurnal Species

Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision.

scholarly journals Astronomy at the service of the Islamic society

2009 ◽  
Vol 5 (S260) ◽  
pp. 514-521
Author(s):  
Ilias M. Fernini
Keyword(s):  
Proper Time ◽  
Astronomical Observatory ◽  
The Sun ◽  
The Moon ◽  
Scientific Institutions ◽  
Mathematical Astronomy ◽  
Islamic Empire ◽  
New Moon ◽  
Islamic Society

AbstractThe Islamic society has great ties to astronomy. Its main religious customs (start of the Islamic month, direction of prayer, and the five daily prayers) are all related to two main celestial objects: the Sun and the Moon. First, the start of any Islamic month is related to the actual seeing of the young crescent after the new Moon. Second, the direction of prayer, i.e., praying towards Mecca, is related to the determination of the zenith point in Mecca. Third, the proper time for the five daily prayers is related to the motion of the Sun. Everyone in the society is directly concerned by these customs. This is to say that the major impetus for the growth of Islamic astronomy came from these three main religious observances which presented an assortment of problems in mathematical astronomy. To observe these three customs, a new set of astronomical observations were needed and this helped the development of the Islamic observatory. There is a claim that it was first in Islam that the astronomical observatory came into real existence. The Islamic observatory was a product of needs and values interwoven into the Islamic society and culture. It is also considered as a true representative and an integral par of the Islamic civilisation. Since astronomy interested not only men of science, but also the rulers of the Islamic empire, several observatories have flourished. The observatories of Baghdad, Cairo, Córdoba, Toledo, Maragha, Samarqand and Istanbul acquired a worldwide reputation throughout the centuries. This paper will discuss the two most important observatories (Maragha and Samarqand) in terms of their instruments and discoveries that contributed to the establishment of these scientific institutions.

scholarly journals XLIV. Variation of the compass, as observed on board the Endeavour Bark, in a voyage round the World

1771 ◽  
Vol 61 ◽  
pp. 422-432 ◽  
Keyword(s):  
The Sun ◽  
The Moon ◽  
The World

The day of the month is noted according to the nautical account, which therefore in all observations noted P. M. is one day forwarder than the civil account. The latitude in is deduced from the last preceding meridian altitude of the Sun; and the longitude in is corrected by the last observations of the distances of the moon from the Sun and stars.

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