scholarly journals GERBERT OF AURILLAC: ASTRONOMY AND GEOMETRY IN TENTH CENTURY EUROPE

2013 ◽  
Vol 23 ◽  
pp. 467-471 ◽  
Author(s):  
COSTANTINO SIGISMONDI
Keyword(s):  
Rational Approximation ◽  
Equilateral Triangle ◽  
Tenth Century ◽  
The Sun ◽  
Astronomical Observations ◽  
The North ◽  
Celestial Pole ◽  
Gerbert Of Aurillac

Gerbert of Aurillac was the most prominent personality of the tenth century: astronomer, organ builder and music theoretician, mathematician, philosopher, and finally pope with the name of Silvester II (999–1003). Gerbert introduced firstly the arabic numbers in Europe, invented an abacus for speeding the calculations and found a rational approximation for the equilateral triangle area, in the letter to Adelbold here discussed. Gerbert described a semi-sphere to Constantine of Fleury with built-in sighting tubes, used for astronomical observations. The procedure to identify the star nearest to the North celestial pole is very accurate and still in use in the XII century, when Computatrix was the name of Polaris. For didactical purposes the Polaris would have been precise enough and much less time consuming, but here Gerbert was clearly aligning a precise equatorial mount for a fixed instrument for accurate daytime observations. Through the sighting tubes it was possible to detect equinoxes and solstices by observing the Sun in the corresponding days. The horalogium of Magdeburg was probably a big and fixed-mount nocturlabe, always pointing the star near the celestial pole.

scholarly journals Archaeoastronomical Aspects of the Archaeological Monuments of Siberia

2012 ◽  
Vol 16 (1 and 2) ◽  
pp. 109-117
Author(s):  
Leonid Marsadolov
Keyword(s):  
The Sun ◽  
The Moon ◽  
Astronomical Observations ◽  
The North ◽  
Ancient People ◽  
Celestial Bodies ◽  
Night Sky

The necessity of astronomical observations for nomadic peoples of Eurasia was based on the sacral meaning of time. The celestial bodies, the Sun and the Moon were parts of cult of the Sky. During annual migrations, in particular those where there were no reliable landmarks, nomads navigated with the North Star and the main constellations of the night sky. Remains left by these nomads, including rock pictures, barrows and observation posts are the legacy of a complex, organised system reflecting the relations of ancient people with the cosmos.

Assessing the temporal reliability of rhythm metrics

2011 ◽  
Vol 41 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Rachael-Anne Knight
Keyword(s):  
Current Paper ◽  
Empirical Measure ◽  
The Sun ◽  
British English ◽  
The North ◽  
North Wind ◽  
The Stability ◽  
Current Popularity ◽  
Temporal Reliability

Despite the current popularity of rhythm metrics, there has been relatively little work aimed at establishing their validity or reliability, important characteristics of any empirical measure. The current paper focuses on the stability, or temporal reliability, of rhythm metrics by establishing if they give consistent results for the same speakers, in the same task, on successive occasions. Four speakers of Southern British English were recorded reading ‘The North Wind and the Sun’ (NWS) passage on three consecutive days. Results indicated that some measures correlate more highly across time than others, and the choice of a measure that is both reliable and valid is discussed. It is suggested that the metric that best fits these criteria is formulated in terms of the proportion of vowels within an utterance (%V).

Detection of a change in the North-South ratio of count rates of particles of high-energy cosmic rays during a change in the polarity of the magnetic field of the Sun

JETP Letters ◽  
2015 ◽  
Vol 101 (4) ◽  
pp. 228-231
Author(s):  
A. V. Karelin ◽  
O. Adriani ◽  
G. C. Barbarino ◽  
G. A. Bazilevskaya ◽  
R. Bellotti ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
High Energy ◽  
The Sun ◽  
High Energy Cosmic Rays ◽  
The North ◽  
The Magnetic Field

scholarly journals Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximum

2003 ◽  
Vol 21 (6) ◽  
pp. 1217-1228 ◽  
Author(s):  
R. B. McKibben ◽  
J. J. Connell ◽  
C. Lopate ◽  
M. Zhang ◽  
J. D. Anglin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Polar Regions ◽  
The Sun ◽  
The South ◽  
The North ◽  
Inner Heliosphere

Abstract. In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum.  Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ~10 MeV and extending up to >70 MeV, the intensities are often dominated by Solar Energetic Particles (SEPs) accelerated near the Sun in association with intense solar flares and large Coronal Mass Ejections (CMEs). At lower energies the particle intensities are almost constantly enhanced above background, most likely as a result of a mix of SEPs and particles accelerated by interplanetary shocks. Simultaneous high-latitude Ulysses and near-Earth observations show that most events that produce large flux increases near Earth also produce flux increases at Ulysses, even at the highest latitudes attained. Particle anisotropies during particle onsets at Ulysses are typically directed outwards from the Sun, suggesting either acceleration extending to high latitudes or efficient cross-field propagation somewhere inside the orbit of Ulysses. Both cosmic ray and SEP observations are consistent with highly efficient transport of energetic charged particles between the equatorial and polar regions and across the mean interplanetary magnetic fields in the inner heliosphere.Key words. Interplanetary physics (cosmic rays) – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections)

scholarly journals XXI. On the dispersive power of the atmosphere, and its effect on astronomical observations

1815 ◽  
Vol 105 ◽  
pp. 375-383
Keyword(s):  
The Sun ◽  
Astronomical Observations ◽  
Dark Glass ◽  
Dispersive Power

Notwithstanding the pains which astronomers have taken to determine accurately the refraction of mixed light, nothing, I believe, has ever been done towards ascertaining the dispersive power of common air, or comparative degree of refrangibility of the differently coloured rays in their passage through our atmosphere. The importance of such an inquiry, however, must be obvious to every one who duly considers the effect which the different degrees of refrangibility of the variously coloured lights must necessarily produce in the apparent situations of differently coloured objects. Stars of different colours must be differently refracted, and the apparent altitude of the sun must vary according to the colour of the dark glass through which he is viewed.

The Koshi’s Revenge

2012 ◽  
Author(s):  
Cheryl Colopy
Keyword(s):  
The Sun ◽  
The West ◽  
Nepal Himalaya ◽  
Great Range ◽  
Half Century ◽  
The Past ◽  
The North ◽  
Past Half Century ◽  
Great Rivers ◽  
Past Half

The Koshi spoke during the monsoon of 2008. She opened a new path, just as Dinesh Mishra predicted. The river breached an apparently ill-constructed and certainly ill-maintained embankment. A photo taken as the flood began shows the ridge of sand dissolving as water poured through a widening gap in the embankment and flowed southeast. In both Nepal and Bihar, villages and farms that had not seen a flood for the past half century were devastated. The embankments on the Koshi had already breached seven times at various spots downriver. This time the entire river below the Siwalik range in Nepal, where the land flattens, had essentially jumped out of its straitjacket and returned to one of its old channels—one it had flowed down two centuries ago. In Nepal the Koshi River is known as the Saptakoshi, or “seven Koshis,” because seven Himalayan rivers merge to create it. The Tamur flows down from Kanchenjunga in eastern Nepal near its border with Bhutan and India; the Arun comes down from Tibet. Out of the Khumbu comes the Dudh Koshi, the milky blue river that entranced me on the way up to Gokyo. The Dudh Koshi joins the Sun Koshi, which is also fed by the Tama Koshi, which in turn receives water from the Rolwaling Khola and Tsho Rolpa, the threatening glacial lake I visited during the monsoon of 2006. From farther west, toward Kathmandu, come the Likhu and the Indrawati. The latter receives the as yet undiverted waters of the Melamchi Khola. These seven tributaries of the Saptakoshi drain more than a third of the Nepal Himalaya, the wettest and highest of the great range, which includes the Khumbu and Ngozumpa glaciers. The Koshi drains almost thirty thousand square miles. It is Nepal’s largest river and one of the largest tributaries of the Ganga. Less than ten miles above the plains, three of these great rivers come together in a final merging: the Sun Koshi from the west, the Arun from the north, the Tamur from the east.

James Bradley, Sailing on the Thames

Lightspeed ◽  
2019 ◽  
pp. 49-57
Author(s):  
John C. H. Spence
Keyword(s):  
Eighteenth Century ◽  
Experimental Evidence ◽  
The Sun ◽  
Theory Of Relativity ◽  
Speed Of Light ◽  
Astronomical Observations ◽  
The Earth ◽  
Independent Estimate ◽  
The Universe ◽  
At Home

The story of the astronomical observations of James Bradley in the eighteenth century, whose measurements of the small movements of a star throughout the year provided an independent estimate of the speed of the Earth around the Sun relative to the speed of light. His work provided the first experimental evidence in support of Copernicus’s theory that the earth is in motion, and against the idea that it is stationary at the center of the universe. His simple telescope at home, his brilliant idea and perseverance, and his life’s work and influence. The importance of his result for the development of Einstein’s theory of relativity and for theories of the Aether in the following centuries.

Against the Grain. Colonialism and the Demise of the Bunya Gatherings, 1839 – 1939

2002 ◽  
Vol 9 (2) ◽  
pp. 47-64 ◽  
Author(s):  
Raymond Evans
Keyword(s):  
Race Relations ◽  
The Sun ◽  
Blue Mountains ◽  
The North ◽  
North Eastern ◽  
History Of ◽  
Eastern Periphery

The white man dropped from the sun bright skyFor he envied the blackfellows' land,With greed and revenge in his restless eyeAnd disease and death in his hand.And he grasped the forest, and seized the strandAnd claimed the blue mountains high…Songs of the Carobra (1855)You literally could not kill an Aborigine with an axe.Toowoomba Chronicle (1919)Idyllic accounts of South-East Queensland's triennial bunya festivals - invariably written by Europeans - seem to float like beckoning mirages above a relative historiographical desert.' The story of the bunya gatherings in the coastal Blackall Ranges or in the Bunya Mountains, at the north-eastern periphery of the Darling Downs, is largely cut adrift from the intricate race relations history of these districts, its aura of ‘romantic reminiscence’ conveniently unsullied by surrounding patterns of colonialism, racism and violence which punctuate the extended process of European intrusion and displacement.

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