Thales and the Diameter of the Sun and Moon

1956 ◽  
Vol 76 ◽  
pp. 105-105
Author(s):  
A. Wasserstein
Keyword(s):  
Small Angle ◽  
Mathematical Knowledge ◽  
Time Measurement ◽  
Angular Measurement ◽  
The Sun ◽  
The Moon ◽  
Actual Measurement ◽  
Greek Philosopher ◽  
Mathematical Techniques

In Vol. LXXV (1955) of the JHS I suggested that the determination of the angular diameters of the sun and the moon ascribed to Thales (Diog. Laertius I. 24) may have been obtained by angular measurement, not as is generally supposed by time-measurement. However, the question of the precise technical method that may have been employed was left open. To measure a very small angle with any degree of accuracy is obviously not easy; and a combination of actual measurement with calculation is probably necessary. In what follows I describe a method of measuring very small angles: whether this was the method employed in obtaining the result ascribed to Thales I do not know; all I can claim is that it presupposes neither mathematical knowledge nor mathematical techniques which could not have been at the disposal of an early Greek philosopher-mathematician.

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 The Lunar orbit paradox

2013 ◽  
Vol 40 (1) ◽  
pp. 135-146
Author(s):  
Aleksandar Tomic
Keyword(s):  
Inertial Mass ◽  
Lunar Orbit ◽  
The Sun ◽  
The Moon ◽  
The Earth ◽  
Three Body ◽  
Origin Of The Moon ◽  
Force Intensity ◽  
Critical Consideration

Newton's formula for gravity force gives greather force intensity for atraction of the Moon by the Sun than atraction by the Earth. However, central body in lunar (primary) orbit is the Earth. So appeared paradox which were ignored from competent specialist, because the most important problem, determination of lunar orbit, was inmediately solved sufficiently by mathematical ingeniosity - introducing the Sun as dominant body in the three body system by Delaunay, 1860. On this way the lunar orbit paradox were not canceled. Vujicic made a owerview of principles of mechanics in year 1998, in critical consideration. As an example for application of corrected procedure he was obtained gravity law in some different form, which gave possibility to cancel paradox of lunar orbit. The formula of Vujicic, with our small adaptation, content two type of acceleration - related to inertial mass and related to gravity mass. So appears carried information on the origin of the Moon, and paradox cancels.

The Moon and Planets Among the Incas and Other Pre-Hispanic Andean Peoples

2020 ◽  
Author(s):  
Mariusz Ziółkowski
Keyword(s):  
Regulatory Function ◽  
The Sun ◽  
The Moon ◽  
Accurate Analysis ◽  
Male Adolescents ◽  
Initiation Rites ◽  
The Andes ◽  
Military Campaigns ◽  
Architectural Structures

Although the Inca state (ca. 1200–1572 ce) was called the Empire of the Sun, the Moon was, in some respects, an equally important divinity in the official state cult. The regulatory function of the phases of the synodic cycle of the Moon in different kinds of social activities, especially those framed in calendrical systems but also military campaigns, is well documented. As far as the orientation of architectural structures is concerned, the researchers focus their attention almost entirely on the position of the Sun. However, a more accurate analysis of two well-known sites—the caves of Intimachay and Inkaraqay—may provide evidence of their function as observatories of the lunar 18.6-year cycle. Those results may confirm the hypothesis, presented some years ago, that the Incas had elaborated a rudimentary method of predicting lunar eclipses. The determination of the exact role of Venus and other planets in the Inca worldview encounters a serious limitation: in contrast to Mesoamerica, in Tahuantinsuyu and the Andes, there are no important “first-hand” sources such as the calendrical-astronomical data of the Maya or the Aztecs. Only Venus seems to have enjoyed a cult of Pan-American range. The morning appearance of Venus was apparently related to the puberty initiation rites of male adolescents, while its appearance as Evening Star seems to have been closely symbolically related to the Inca sovereign and his military activities. Putting aside the information available on Venus and its cult, there is an almost complete lack of data on the other planets. Another problem must be considered: To what extent did the Incas inherit their knowledge from their predecessors, the Chimus, or even earlier cultures?

scholarly journals MEMAHAMI MAKNA HILAL MENURUT TAFSIR AL-QUR’AN DAN SAINS

UNIVERSUM ◽  
2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Qomarus Zaman
Keyword(s):  
The Sun ◽  
The Moon ◽  
Majority Opinion ◽  
Timing System ◽  
The Future ◽  
New Moon ◽  
The Times ◽  
Modern Astronomy

Interpretation of surah Al-Baqarah verse 189 which uses a method of transmission saying that the verse would describe the times predetermined by God to mankind in serve him well to explain when fasting, and pilgrimage feast. Similarly, the new moon will also indicate the prescribed period for women. Narrated by Bisyri bin Mu'adh said that Qatada once said: The Prophet Muhammad was asked one day by his people will paragraph يسألونك عن الأهلة قل هي مواقيت للناس at the time of the new moon has not yet appeared? Then the Prophet said to them; Then the Prophet said to them; Allah have it appear as what ever you know. هي مواقيت للناس therefore to bring it up then he is as a sign on the start of fasting for the Muslims and for Iftar (feast) and indicates the time for those with the arrival of the rituals of Hajj and to determine the future iddahnya women.Hilal is a sign or marker clue is a unity of time and timing system consisting of day, month and year. This has been the form of a calendar (almanac, Taqwim) used easily for the benefit of mankind in the implementation of fasting, pilgrimage, prayer time, the determination of the prescribed period and other mualamah agreement. In view of modern astronomy as Danjon, the new moon will be visible if the position of the moon within a minimum of 8 degrees in addition to the sun (the moon's crescent cauld rot be seen closer to the sun for elongation less that 80). This opinion was never confirmed by Muammer Dizer the International Islamic Conference in Istanbul Turkey in 1978, according to research that has been accepted by international astronomers declared that the moon looks at the position of the sun distance (angle of azimut) 80 and the position of elevation above the horizon of 50. He stated it is impossible if there is a majority opinion expressed in the following 50 positions height above the horizon can be seen with the eye. While MABIMS including Indonesia make imkan al-rukyat criteria states that the size of the moon positions can be seen at a height of 20, 30 the azimut distance elongation angle and distance when ijtimak and sunset time of 8 hours (kiteria to 20, 30 and 8 hours). MABIMS criteria is lower than the criterion Istanbul. This last criterion used Malaysia Singapore and Brunei, while Indonesia is still no difference and there is no agreement on these criteria.Keywords; Hilal, Masa Iddah, Taqwim, Imkan al-rukyat

scholarly journals Delima of the Fixation and Determination of Qibla

Fahm-i-Islam ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 01-19
Author(s):  
Dr. Rashida Parveen
Keyword(s):  
Natural Phenomenon ◽  
The Sun ◽  
The Moon ◽  
Astronomical Instruments

Islamic Shari'ah is universal, all its injunctions are based on comfort, easiness and openness, instead of deep philosophical and mathematical delicacies. This is only because of the fact that the jurisdictions of the "Islamic Shari'ah" are the sea and land , the black and red including all residents of these regions. Furthermore, if the obligations of Islam e.g.," "الصلوۃand " "الصومetc, are obligatory for the "residents"of cities and other educated people, exactly in the same way these are for the inhabitants of villages, islands and the ignorant individuals too. Subsequent upon this, it is very much desired by reason, wisdom and special blessing of Allah (S.W.T) that the "Shari Ahkam" which are so common, the same should not be made dependent on mathematical delicacies and astronomical instruments. So that all and sundry may perform their obligations easily and with full satisfaction The ambiguities raised by Allama Inayatullah Al-Mashriqi and some Aryan Hindu,s authors regarding the under reference topic named "Delima of the fixation (Determination) of Qibla" shall thoroughly be discussed. This paper will argue and let those facts go through the researching and inductive stages to explore the valuable realities. Efforts would be exerted to arrive at the conclusion that in the Delima of Fixation (Determination) of "Qiblah" all of our religious forefathers (predecessors) e.g. ""تابعین" ,"صحابہand " "تبع تابعین shall be strictly followed. It means, that we must fix (determine) the "Qibla'h's" position (direction) on account of only estimation ( ) تقلید و تحریthrough the significant signs of the natural phenomenon (i.e) the rising and setting of the Sun, the Moon, besides identification of some of the stars; and not through the man made, scientific and mythological hypothesis.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

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.

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