scholarly journals On the effects of temperature on the intensity of magnetic forces; and on the diurnal variation of the terrestrial magnetic intensity

1833 ◽  
Vol 2 ◽  
pp. 225-226
Keyword(s):  
Maximum Intensity ◽  
Diurnal Changes ◽  
The Sun ◽  
Magnetic Intensity ◽  
The Moon ◽  
Magnetic Forces ◽  
Effects Of Temperature ◽  
New Moon ◽  
Magnetic Meridian ◽  
Minimum Intensity

The details of the author’s experiments upon the above subjects are given in an extended series of tables, commencing with a tempe­rature of — 3° Fahr. up to 127° Fahr. Mr. Christie found that as the temperature of the magnets increased, their intensity diminished, in direct contradiction to the notion of destroying magnetism by in­tense cold. From a temperature of 80° the intensity decreased rapidly as the temperature increased, and at above 100° a portion of the power of the magnet was permanently destroyed. In regard to the diurnal changes in the terrestrial intensity, the author’s experiments lead him to suggest the following queries for the consideration of those who may have an opportunity of making such observations:—Does the time of the minimum intensity corre­spond with the time at which the sun is on the magnetic meridian ? Does the time of maximum intensity correspond to the sun’s passing the plane of the equator of the dipping-needle ? Does any change take place in the intensity while the sun is below the horizon ? Are any periodical effects corresponding to the time of rotation of the sun about its axis observable ? Is the diurnal change of intensity at the time of new moon sensibly different from what it is at the time of quadrature ? If the moon do produce an effect on the needle, it is evidently less than that of the sun;—should we then attribute it to solar heat, or to the magnetism of the sun ?

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.

A Graphical Approach to Some Problems in Maya Astronomy

1946 ◽  
Vol 12 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Robert H. Merrill
Keyword(s):  
Graphical Methods ◽  
The Sun ◽  
The Moon ◽  
Graphical Approach ◽  
New Moon ◽  
Dresden Codex

Although graphical methods are in common use by engineers and astronomers, they are less familiar to archaeologists. To portray the rhythm of celestial motions, astronomers often use “elongation” diagrams to show angular distances of moon and planets from the sun on each day of the calendar year.The Maya recognized a zone within which the planets could not be seen because of proximity to the brilliant disk of the sun. The moon cannot be seen on the day of conjunction with the sun, and is generally invisible on the day before and the day after this “new moon day.” The three consecutive days in the lunar table of the Dresden Codex may represent the 3-day phase of moon disappearance.

Decapitated Lunar Goddesses in Aztec Art, Myth, and Ritual

1997 ◽  
Vol 8 (2) ◽  
pp. 185-206 ◽  
Author(s):  
Susan Milbrath
Keyword(s):  
Solar Eclipse ◽  
Seasonal Cycle ◽  
Full Moon ◽  
The Sun ◽  
The Moon ◽  
Seasonal Transition ◽  
The Earth ◽  
New Moon ◽  
The Demonic

AbstractAztec images of decapitated goddesses link the symbolism of astronomy with politics and the seasonal cycle. Rituals reenacting decapitation may refer to lunar events in the context of a solar calendar, providing evidence of a luni-solar calendar. Decapitation imagery also involves metaphors expressing the rivalry between the cults of the sun and the moon. Huitzilopochtli's decapitation of Coyolxauhqui can be interpreted as a symbol of political conquest linked to the triumph of the sun over the moon. Analysis of Coyolxauhqui's imagery and mythology indicates that she represents the full moon eclipsed by the sun. Details of the decapitation myth indicate specific links with seasonal transition and events taking place at dawn and at midnight. Other decapitated goddesses, often referred to as earth goddesses with “lunar connections,” belong to a complex of lunar deities representing the moon within the earth (the new moon). Cihuacoatl, a goddess of the new moon, takes on threatening quality when she assumes the form of a tzitzimime attacking the sun during a solar eclipse. The demonic new moon was greatly feared, for it could cause an eternal solar eclipse bringing the Aztec world to an end.

XIV. A comparison of the changes of magnetic intensity throughout the day in the dipping and horizontal needls, at Treurenburgh Bay in Spitsbergen

1828 ◽  
Vol 118 ◽  
pp. 303-311
Keyword(s):  
Diurnal Changes ◽  
The Sun ◽  
Magnetic Intensity ◽  
Terrestrial Magnetism ◽  
The Earth ◽  
The World ◽  
East And West ◽  
The Times ◽  
Rotatory Motion

The few observations I had an opportunity of making at Port Bowen in 1825, on the diurnal changes of intensity shown by the dipping and horizontal needles, first suggested the idea of a daily rotatory motion of the general polarizing axis of the earth, as the cause, not only of the diurnal changes of intensity, but also of the diurnal oscillations of the horizontal needle throughout the world. And the circumstance, of the times of the maximum and minimum effect of these phænomena, occurring generally when the sun bore north, south, east, and west by compass, indicated his agency in producing this motion of the pole. The entire confirmation of an hypothesis so important in the theory of terrestrial magnetism, requires the evidence of varied and extensive observation; and as my professional pursuits have recently led me to revisit those regions best calculated for the experiments, I have thought a continuation of them under favourable circumstances, might prove an useful auxiliary to those already honoured with a place in the Philosophical Transactions for 1826.

Mississippian Solstice Shrines and a Cahokian Calendar: An Hypothesis Based on Ethnohistory and Archaeology

1988 ◽  
Vol 8 (3) ◽  
pp. 227-247 ◽  
Author(s):  
Patricia J. O'Brien ◽  
William P. McHugh
Keyword(s):  
Full Moon ◽  
The Sun ◽  
Summer Solstice ◽  
The Moon ◽  
Winter Solstice ◽  
Vernal Equinox ◽  
Religious Ritual ◽  
Autumnal Equinox ◽  
New Moon ◽  
Using Data

This article examines the hypothesis that early Middle Mississippians had a calendric system which tied agriculture and religious ritual together. It also suggests that to that end they built solstice shrines as a means of recording the passage of time through the behavior of the sun and the moon. Using data from structures having possible astronomical alignments, from historic-ethnographic-linguistic sources, and from agricultural planting cycles, a “Cahokian calendar year” is constructed. The year begins with the summer solstice and the Great Busk ceremony. At the next full moon the “great corn” is planted to be harvested at the autumnal equinox. At the winter solstice winter begins while the vernal equinox is marked by a ritual for the Great Sun, their ruler. At the next new moon after that rite a “little corn” is planted which is harvested at the Great Busk. In their five-day, thirteenth month, just before the Busk, all the fires in the society are extinguished to be relit at the summer solstice Great Busk ceremony.

scholarly journals XVI. On magnetic influence in the solar rays

1826 ◽  
Vol 116 ◽  
pp. 219-239 ◽  
Keyword(s):  
The Sun ◽  
Fine Hair ◽  
Magnetic Forces ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Series Of Experiments ◽  
Effects Of Temperature ◽  
The Times ◽  
Magnetic Needle ◽  
Solar Rays

The object of the present communication is to show, by a series of experiments, that the solar rays possess sensible magnetic properties, which are observable in the vibrations of a magnetised needle exposed to those rays, independently of the effects produced by the heat which they impart. I propose likewise to point out the changes which take place in the intensity of a magnetised needle from changes of temperature, as deducible from the times of its vibration. I have before stated in my paper on the effects of temperature on the intensity of magnetic forces , that, in deducing the terrestrial magnetic intensity by means of the vibrations of a needle, a correction ought to be introduced where the observations have been made at different temperatures. I had not at the time made any experiments by which I could ascertain how far changes in the temperature of a needle would be sensible in the time of its vibration; and the first observations which I made with this view being with a light needle, did not give very decided results: they however led me first to notice the very singular fact, that a magnetic needle comes to rest more quickly when vibrated exposed to the rays of the sun, than when vibrated in the shade. In order to ascertain the effect which changes of temperature have on the times of vibration of a needle, it is necessary to know the temperature of the needle itself during the observations, and I saw no better means of ascertaining this, even approximately, than to vibrate it in the shade and then exposed to the rays of the sun, and to consider the temperature of the needle to be that indicated by a thermometer near to it. On my first doing this, I found, that although I could easily mark the 50th vibration when the needle was shaded, I could not distinguish beyond the 40th when it was exposed. I at the same time found that the time of vibration was slightly diminished at the higher temperature, instead of being increased, as I had reason to expect. As however the needle was not vibrated in the same spot in the two cases, the diminution in the time of vibration and of the arc when it was exposed, might be independent of the change of temperature and of any influence in the solar rays. To avoid any uncertainty arising from difference of disturbing causes in two situations, I placed the compass out of doors, with a screen composed intirely of wood, supported at the height of four feet above it, and by removing which the rays of the sun struck directly on the needle. A thermometer having the bulb near to the compass-box indicated nearly the temperature of the needle. When the shutter was up, so that the needle vibrated in the shade, I could very distinctly note the 100th vibration; but when it was removed and the needle vibrated exposed to the sun's rays, I could not so distinctly mark the 75th. I made use of a needle six inches long, weighing 42.75 grains, and contained in a brass compass-box with a glass cover: the needle was suspended by a fine hair, and commenced vibrating 30° from zero.

scholarly journals THE RELEVANCE OF USING THE MOON’S AGE AS AN ALTERNATIVE IN IMKANUR RUKYAH CRITERIA

2016 ◽  
Vol XLII-4/W1 ◽  
pp. 209-215 ◽  
Author(s):  
S. Anwar ◽  
K. M. Omar ◽  
M. S. Che Awang
Keyword(s):  
The Sun ◽  
The Moon ◽  
New Moon

The Imkanur rukyah criteria can be defined as the minimum limit in expecting the new moon’s visibility in determining the beginning of Hijri months. It has been used in the development of Hijri calendar in Malaysia since 1992. Based on the criteria, the new moon is considered visible if the altitude at sunset is at least 2&amp;deg; and the elongation between the moon and the sun is at least 3&amp;deg;, or at moonset, the age of the moon is at least 8 hours. The altitude limit of 2&amp;deg; and the elongation limit of 3&amp;deg; indeed were determined according to the data of new moon visibility observed in Indonesia, whereas for the 8-hour moon’s age, there is no written rule regarding to it. The use of the moon’s age criterion as an alternative to the geometric criteria can lead to confusion if both conditions provide different results. Therefore, this study was performed to assess the relevance of using moon’s age as an alternative in <i>Imkanur rukyah</i> criteria used in Malaysia. The study utilised the data of the sun and the moon’s positions, the time of sunset, the time of moonset and the time of conjunction (new moon). The data for the sun were calculated based on VSOP87 theory, while for the moon, using ELP2000-82b. Based on the analysis, in determining Hijri dates from 1996 to 2015, there are 22 discrepancies found between the moon’s age and the geometric criteria, in which, 5 of them occur in the month of Ramadan, Syawal and Zulhijjah. These conditions show that the moon’s age criterion is not always consistent with the geometric criteria. Therefore, the use of moon’s age as an alternate criterion in determining the beginning of Hijri month is considered irrelevant and should be further reviewed.

scholarly journals The moon phases influence on the beginning of astronomical dawn determination in Yogyakarta

2017 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Abu Yazid Raisal ◽  
Yudhiakto Pramudya ◽  
Okimustava Okimustava ◽  
Muchlas Muchlas
Keyword(s):  
Full Moon ◽  
Moving Average ◽  
Weather Condition ◽  
The Sun ◽  
The Moon ◽  
Moon Phases ◽  
Brightness Level ◽  
Sky Brightness ◽  
New Moon ◽  
The Difference

<p class="Abstract">In astronomy, there are three types of dawn. They are astronomical, nautical, and civil dawn. The sunlight is starting to appear on the east horizon when the Sun altitude is 18<sup>o</sup> below the horizon. Hence, there is a change on the sky brightness. The sky brightness can be affected by the moon phases. The sky brightness level is monitored by Sky Quality Meter (SQM). The SQM was installed upward to the zenith. There are 4 locations of measurement in Yogyakarta. The data has been collected for nine months to obtain the complete moon phases. The beginning of astronomical dawn is time when the sky brightness level is starting to decrease. The moving average algorithm was employed to determine the beginning of astronomical dawn. The time when the astronomical dawn begins is compared with the sun altitude calculation. The sun altitude calculation has been done using accurate times software. The difference of the beginning of astronomical dawn by measurement and calculation are 18.61±6.81 minutes, 19.12±3.28 minutes, 31.12±7.76 minutes, and 27.24±8.04 minutes, on the new moon (0), on the first quarter (0.25), on the full moon (0.5) and on the last quarter (0.75), respectively. The weather condition is also contributing to the results.</p>

XVII. Experimental inquiries relative to the distribution and changes of the magnetic intensity in ships of war

1824 ◽  
Vol 114 ◽  
pp. 310-353
Keyword(s):  
Magnetic Intensity ◽  
Magnetic Forces ◽  
The Earth ◽  
Constant Height ◽  
Peculiar Form ◽  
Magnetic Meridian

It having appeared from many unquestionable experiments, that the variation of this compass, as determined on shipboard, is subject to remarkable anomalies, arising from the unequal influence of the iron distributed through the various parts of a vessel, and from the changeable intensity of the same, occasioned by the different directions of the ship's head, with respect to the magnetic meridian, and from its different situations on the surface of the earth, it seemed desirable that some attempt should be made, to discover in what way the attractive forces are distributed throughout the vessel, and particularly in the vicinity of the binnacle, by a series of careful experiments. To trace the variations in the intensity of the magnetic forces, under the simplest circumstances possible, the Scylla gun brig was selected, having no other iron in her than what was necessarily employed in her construction, and for the ballast of a ship of her class, when in a state of ordinary. The intensity was estimated in planes parallel to the decks, and (excepting in a very few cases, where the peculiar form of a ship prevented) at the constant height of the binnacle above them.

Sign in / Sign up

Export Citation Format

Share Document