Contributions to the discussion on astronomy in ancient literate societies

1974 ◽  
Vol 276 (1257) ◽  
pp. 117-121
Keyword(s):  
New World ◽  
The Other ◽  
Striking Difference ◽  
The Sun ◽  
Summer Solstice ◽  
Winter Solstice ◽  
Vernal Equinox ◽  
The Earth ◽  
The Hours ◽  
Autumnal Equinox

A. Digby (The Paddocks, Eastcombe, Stroud, Gloucestershire) I think the most striking difference between Old World and New World calendrical systems which has emerged from the papers today is the use in America of a 260-day period combining the 20 day names with the numerals 1 to 13. There is a possibility that the number thirteen may have been determined by the characteristics and shortcomings of a peculiar sundial which could be used to determine annual as well as diurnal time by showing the declination as well as the hour angle of the sun. The evidence for the existence of this instrument lies in examples of the year glyph which can be shown to be a drawing of two trapezes set at right angles on a ring. One lying north to south would cast a shadow which would move from west to east across the base of the instrument between the hours of about 7 a.m. and 5 p.m., while the other, a taller trapeze would cast a shadow that travels across the instrument in a direction from south to north and back reflecting the declination of the Sun. There is some evidence to show that the instrument was tilted with the base parallel to the axis of the Earth like a ‘polar sundial’ (paper read to a symposium on recent Mesoamerican research, Cambridge 1972). Under these conditions, the shadow would make four traverses of equal length in the course of the year: from the centre of the instrument to the northern extremity (autumnal equinox to winter solstice); north extremity to centre (winter solstice to vernal equinox); centre to south extremity (vernal equinox to summer solstice); south extremity to centre (summer solstice to autumnal equinox), each of 91J days duration.

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.

Early Modern Spaces in Motion

2020 ◽  
Keyword(s):  
Human Brain ◽  
Early Modern ◽  
Physical Environment ◽  
Social Behaviour ◽  
New World ◽  
Architectural History ◽  
The Sun ◽  
Early Modern Europe ◽  
The Earth ◽  
German Speaking

Stretching back to antiquity, motion had been a key means of designing and describing the physical environment. But during the sixteenth through eighteenth centuries, individuals across Europe increasingly designed, experienced, and described a new world of motion: one characterized by continuous, rather than segmented, movement. New spaces that included vistas along house interiors and uninterrupted library reading rooms offered open expanses for shaping sequences of social behaviour, scientists observed how the Earth rotated around the sun, and philosophers attributed emotions to neural vibrations in the human brain. Early Modern Spaces in Motion examines this increased emphasis on motion with eight essays encompassing a geographical span of Portugal to German-speaking lands and a disciplinary range from architectural history to English. It consequently merges longstanding strands of analysis considering people in motion and buildings in motion to explore the cultural historical attitudes underpinning the varied impacts of motion in early modern Europe.

Observation of the winter solstice 1812, with the mural circle at Greenwich

1832 ◽  
Vol 1 ◽  
pp. 457-457
Keyword(s):  
Slight Modification ◽  
The Sun ◽  
Summer Solstice ◽  
Winter Solstice ◽  
Separate Paper ◽  
The Subject

The weather was so extremely unfavourable, that it was not possible to obtain more than eight observations of the sun, from which the obliquity of the ecliptic at the late solstice could be deduced; from these it is inferred to have been 23° 27' 47''·35, that from the summer solstice having been 23° 27' 51''·3. This small discordance, it is observed, might be easily made to disappear by a slight modification of Bradley’s refractions; but the Astronomer Royal has not yet had an opportunity of making a sufficient number of observations on circumpolar stars with the new circle, to warrant making any corrections in his table of refractions, and he leaves the subject of the discordance of the solstices for discussion in a separate paper.

scholarly journals XVII. Observation of the winter solstice of 1812, the mural circle at Greenwich

1813 ◽  
Vol 103 ◽  
pp. 123-125
Keyword(s):  
The Other ◽  
Astronomical Observation ◽  
The Sun ◽  
Winter Solstice

The weather this year at the period of the solstice was peculiarly unfavourable for astronomical observation ; however, in the course of the month, I obtained nine observations of the sun; one of these proved defective, the result of the other eight, accompanies this communication.

Solar Motion and Lunar Eclipses in Philolaus’ Cosmological System

Apeiron ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dirk L. Couprie
Keyword(s):  
The Other ◽  
The Sun ◽  
The Moon ◽  
Internal Logic ◽  
Wrong Side ◽  
The Earth ◽  
Solar Motion ◽  
Length Of The Day

Abstract In this paper, three problems that have hardly been noticed or even gone unnoticed in the available literature in the cosmology of Philolaus are addressed. They have to do with the interrelationships of the orbits of the Earth, the Sun, and the Moon around the Central Fire and all three of them constitute potentially insurmountable obstacles within the context of the Philolaic system. The first difficulty is Werner Ekschmitt’s claim that the Philolaic system cannot account for the length of the day (νυχϑήμερον). It is shown that this problem can be solved with the help of the distinction between the synodic day and the sidereal day. The other two problems discussed in this paper are concerned with two hitherto unnoticed deficiencies in the explanation of lunar eclipses in the Philolaic system. The Philolaic system cannot account for long-lasting lunar eclipses and according to the internal logic of the system, during lunar eclipses the Moon enters the shadow of the Earth from the wrong side. It is almost unbelievable that nobody, from the Pythagoreans themselves up to recent authors, has noticed these two serious deficiencies, and especially the latter, in the cosmology of Philolaus the Pythagorean.

scholarly journals XXI. On magnetic influence in the solar rays

1828 ◽  
Vol 118 ◽  
pp. 379-396 ◽  
Keyword(s):  
The Other ◽  
The Sun ◽  
The Earth ◽  
Circular Arcs ◽  
Solar Rays

The facts which I communicated in my former paper on this subject appeared so inexplicable on any known principle, that I am induced to present my subsequent observations to the Society, although I have not succeeded in ascertaining the causes of the singular effects which I have observed. From the experiments described in that paper, it appeared that a magnetized needle, when vibrated exposed to the sun’s rays, will come to rest sooner than when screened from their influence: that a similar effect is produced on a needle of glass or of copper; but that the effect upon the magnetized needle greatly exceeds that upon either of the others. To the experiments from which this was inferred, it might be objected, that the magnetized needle and the other metallic needle were not of the same weight, and that the effect upon an unmagnetized steel needle had not been compared with that upon a similar needle magnetized. I therefore, on the first opportunity, made these experiments in the most unexceptionable manner, and the results most decidedly confirmed those I had previously obtained. I endeavoured likewise to ascertain the effects that would be produced by the separate rays; but, possibly owing to the inefficiency of my apparatus, I obtained no very decided results: the violet rays appeared to produce the same effect as partially screening the needle; and the red rays, the greatest effect in diminishing the arc of vibration. The observations themselves will however best point out the nature of these effects. My first object was to compare the effects on an unmagnetized steel needle with those on a magnetized needle, under circumstances as nearly as possible the same. For this purpose I made another needle of the same form and weight, and from the same piece of clock-spring, as the magnetized needle which I had already employed. Each needle had pasteboard glued to the under side, to render it of precisely the same weight as two other needles of copper and of glass, which I had cut of the same form for the purpose of comparing the effects upon needles of different kinds. The length of each needle is 6 inches, and the greatest breadth 1.5 inch, the boundaries being circular arcs. The needles were vibrated by means of an apparatus, described in my former paper, from which metal was scrupulously excluded; the suspending wire being the only metal within several feet of the needle. This wire was of brass, and of such diameter, that the unmagnetized needles vibrated by the force of its torsion in very nearly the same time as the magnetized needle by the directive force of the earth. The observations are contained in the following table, where the terminal arc is, in all cases, the extent to which the needle vibrated beyond zero after completing the 100th vibration; and the terminal excess is the excess of the terminal arc when the needle vibrated in the shade above that when it vibrated exposed to the sun.

scholarly journals The results of observations made at the observatory of Trinity College, Dublin, for determining the obliquity of the ecliptic, and the maximum of the aberration of light

1833 ◽  
Vol 2 ◽  
pp. 114-115
Keyword(s):  
Trinity College ◽  
Sufficient Accuracy ◽  
Zenith Distance ◽  
The Sun ◽  
Summer Solstice ◽  
Winter Solstice ◽  
Trinity College Dublin ◽  
The Mean

The obliquity of the ecliptic, as deduced from the early observations by the Greenwich quadrant, compared with the present obliquity, gives the diminution for an interval of nearly sixty years, with almost sufficient accuracy to state with some confidence the mass of Venus; but to obtain this point with certainty, the present obliquity, deduced from a mean of the observations of different astronomers, should be used. Upon this subject the author alludes to the opinion of astronomers, that observations of the winter solstice have given a less obliquity than those of the summer solstice,—an opinion sustained by the observations of Maskelyne, Arago, and Pond, but questioned by Bessel and Bradley. Dr. Brinkley refers this difference to some unknown modification of refraction; he has observed that at the winter solstice the irregularity of refraction for the sun is greater than for the stars at the same zenith-distance. He points out the necessity of paying attention to the observations at the winter solstice, and gives a table, exhibiting the mean obliquity reduced to January 1813. Dr. Brinkley next alludes to the maximum of the aberration of light, which appears from his observations of last year to be 20"·80.

scholarly journals On a method of comparing the light of the Sun with that of the fixed stars

1833 ◽  
Vol 2 ◽  
pp. 355-355
Keyword(s):  
Full Moon ◽  
Angular Distance ◽  
The Other ◽  
The Sun ◽  
Proper Distance ◽  
The Earth ◽  
Direct Light ◽  
Glass Bulb ◽  
The Mean ◽  
Made In

In the Philosophical Transactions for the year 1767, a suggestion is thrown out by Mr. Michell, that a comparison between the light received from the sun and any of the fixed stars, might furnish data for estimating their relative distances; but no such direct comparison had been attempted. Dr. Wollaston was led to infer from some observations that he made in the year 1799, that the direct light of the sun is about one million times more intense than that of the full moon, and therefore very many million times greater than that of all the fixed stars taken collectively. In order to compare the light of the sun with that of a star, he took, as an intermediate object of comparison, the light of a candle reflected from a small bulb, about a quarter of an inch in diameter, filled with quicksilver, and seen, by one eye, through a lens of two inches focus, at the same time that the star or the sun’s image, placed at a proper distance, was viewed by the other eye through a telescope. The mean of various trials seemed to show that the light of Sirius is equal to that of the sun seen in a glass bulb one tenth of an inch in diameter, at the distance of 210 feet, or that they are in the proportion of one to ten thousand millions; but as nearly one half of the light is lost by reflection, the real proportion between the light from Sirius and the sun is not greater than that of one to twenty thousand millions. If the annual parallax of Sirius be half a second, corresponding to a distance of 525,481 times that of the sun from the earth, its diameter would be 3⋅7 times that of the sun, and its light 13⋅8 times as great. The distance at which the sun would require to be viewed, so that its brightness might be only equal to that of Sirius, would be 141,421 times its present distance; and if still in the ecliptic, its annual parallax in longitude would be nearly 3″; but if situated at the same angular distance from the ecliptic as Sirius is, it would have an annual parallax, in latitude, of 1″⋅8.

Anaximenes and to ΚΡγΣΤΑΛΟΕΙΔΕΣ

1956 ◽  
Vol 6 (1-2) ◽  
pp. 40-44 ◽  
Author(s):  
W. K. C. Guthrie
Keyword(s):  
The Other ◽  
The Sun ◽  
The Earth ◽  
Flat Shape

The following remarks are frankly speculative, and their subject one on which certainty is unlikely to be attained. It seems worth offering them because, though the conclusions are only tentative, they were reached by way of some observations which have a certain interest of their own.Anaximenes, we are told, said that the sun is flat like a leaf, and that it and the other heavenly bodies ‘ride upon’ the air owing to their flat shape, as does the earth also.

scholarly journals Active bodies in the near-Earth region: The tenuous boundary between comets and asteroids

2015 ◽  
Vol 10 (S318) ◽  
pp. 142-143
Author(s):  
Julio A. Fernández ◽  
Andrea Sosa
Keyword(s):  
Dynamical Evolution ◽  
The Other ◽  
General Definition ◽  
The Sun ◽  
Main Belt ◽  
Close Encounters ◽  
The Earth ◽  
Bare Nucleus ◽  
Short Period ◽  
Near Earth Asteroids

AbstractWe analyze the dynamics and activity observed in bodies approaching the Earth (perihelion distancesq< 1.3 au) in short-period orbits (P< 20 yr), which essentially are near-Earth Jupiter Family Comets (NEJFCs) and near-Earth asteroids (NEAs). In the general definition, comets are “active”, i.e. they show some coma, while asteroids are “inactive”, i.e. they only show a bare nucleus. Besides their activity, NEJFCs are distinguished from NEAs by their dynamical evolution: NEJFCs move on unstable orbits subject to frequent close encounters with Jupiter, whereas NEA orbits are much more stable and tend to avoid close encounters with Jupiter. However, some JFCs are found to move on stable, asteroidal-type orbits, so the question arises if these objects are asteroids that have become active, perhaps upon approach to the Sun. In this sense they may be regarded as the counterparts of the main-belt comets (Hsieh & Jewitt 2006). On the other hand, some seemingly inert NEAs move on unstable, comet-type orbits, so the question about what is a comet and what is an asteroid has become increasingly complex.

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