scholarly journals Heraclides of Pontus. Astronomical fragments

2019 ◽  
Vol 13 (2) ◽  
pp. 740-754
Keyword(s):  
The Sun ◽  
Maximum Elongation ◽  
Philosophy Of Nature ◽  
Literary Genres ◽  
The Earth ◽  
Literature History ◽  
Rotation Of The Earth ◽  
Evening Star ◽  
Diurnal Rotation

Heraclides of Pontus (c. 388–310 BCE), a Platonic philosopher, worked in various literary genres and wrote on such topics as psychology, politics, literature, history, geography, astronomy and the philosophy of nature. Nothing is preserved. The present publication contains a collection of the testimonies about Heraclides’ astronomical writings. He thought of an infinite universe, in fact believing that every star is a kosmos, located in the infinite either. He famously advanced the theory of terrestrial rotation, hypothesizing that the apparent diurnal rotation of the heavens is better explained by the rotation of the Earth, and in this context correctly observed that, unlike other planets, Venus as morning and evening star has the maximum elongation from the Sun’s position (that is to say is never located far from the Sun). The evidences are translated and numbered according to a new edition by Schütrumpf et al. 2008.

scholarly journals Seasonal variations and north–south asymmetries in polar wind outflow due to solar illumination

2016 ◽  
Vol 34 (11) ◽  
pp. 961-974 ◽  
Author(s):  
Lukas Maes ◽  
Romain Maggiolo ◽  
Johan De Keyser
Keyword(s):  
Seasonal Variations ◽  
Solar Zenith Angle ◽  
The Sun ◽  
Polar Ionosphere ◽  
Polar Cap ◽  
Polar Wind ◽  
Simple Set ◽  
The Earth ◽  
Rotation Of The Earth ◽  
Set Up

Abstract. The cold ions (energy less than several tens of electronvolts) flowing out from the polar ionosphere, called the polar wind, are an important source of plasma for the magnetosphere. The main source of energy driving the polar wind is solar illumination, which therefore has a large influence on the outflow. Observations have shown that solar illumination creates roughly two distinct regimes where the outflow from a sunlit ionosphere is higher than that from a dark one. The transition between both regimes is at a solar zenith angle larger than 90°. The rotation of the Earth and its orbit around the Sun causes the magnetic polar cap to move into and out of the sunlight. In this paper we use a simple set-up to study qualitatively the effects of these variations in solar illumination of the polar cap on the ion flux from the whole polar cap. We find that this flux exhibits diurnal and seasonal variations even when combining the flux from both hemispheres. In addition there are asymmetries between the outflows from the Northern Hemisphere and the Southern Hemisphere.

scholarly journals Solar Tracker

2020 ◽  
Vol 2 (1) ◽  
pp. 59-65
Author(s):  
Irfan Danial Hashim ◽  
Ammar Asyraf Ismail ◽  
Muhammad Arief Azizi
Keyword(s):  
Fossil Fuels ◽  
Electrical Energy ◽  
Maximum Amount ◽  
Solar Panel ◽  
Angle Of Incidence ◽  
The Sun ◽  
Continuous Change ◽  
The Earth ◽  
Solar Tracker ◽  
Rotation Of The Earth

Solar Tracker The generation of power from the reduction of fossil fuels is the biggest challenge for the next half century. The idea of converting solar energy into electrical energy using photovoltaic panels holds its place in the front row compared to other renewable sources. But the continuous change in the relative angle of the sun with reference to the earth reduces the watts delivered by solar panel. Conventional solar panel, fixed with a certain angle, limits their area of exposure from the sun due to rotation of the earth. Output of the solar cells depends on the intensity of the sun and the angle of incidence. To solve this problem, an automatic solar cell is needed, where the Solar Tracker will track the motion of the sun across the sky to ensure that the maximum amount of sunlight strikes the panels throughout the day. By using Light Dependent Resistors, it will navigate the solar panel to get the best angle of exposure of light from the sun.

scholarly journals Heraclides of Pontus. Life and Writings (fr. 1–21 Schütrumpf)

2019 ◽  
Vol 13 (1) ◽  
pp. 358-374
Keyword(s):  
Philosophy Of Nature ◽  
Literary Genres ◽  
Literature History

Heraclides of Pontus (c. 388–310 BCE), a Platonic philosopher, worked in various literary genres and wrote on such topics as psychology, politics, literature, history, geography, astronomy and the philosophy of nature. Nothing is preserved. The present publication contains a collection of the testimonies about Heraclides’ life and writings. The evidences are translated and numbered according to a new edition by Schütrumpf et al. 2008.

Addendum 2020 to ‘Measurement of the Earth’s rotation: 720 BC to AD 2015’

2021 ◽  
Vol 477 (2246) ◽  
pp. 20200776
Author(s):  
L. V. Morrison ◽  
F. R. Stephenson ◽  
C. Y. Hohenkerk ◽  
M. Zawilski
Keyword(s):  
Angular Momentum ◽  
Earth’S Rotation ◽  
The Sun ◽  
Earth's Rotation ◽  
Moon System ◽  
Link Type ◽  
The Earth ◽  
Solar Eclipses ◽  
Rotation Of The Earth

Historical reports of solar eclipses are added to our previous dataset (Stephenson et al. 2016 Proc. R. Soc. A 472 , 20160404 ( doi:10.1098/rspa.2016.0404 )) in order to refine our determination of centennial and longer-term changes since 720 BC in the rate of rotation of the Earth. The revised observed deceleration is −4.59 ± 0.08 × 10 −22  rad s −2 . By comparison the predicted tidal deceleration based on the conservation of angular momentum in the Sun–Earth–Moon system is −6.39 ± 0.03 × 10 −22  rad s −2 . These signify a mean accelerative component of +1.8 ± 0.1 × 10 −22  rad s −2 . There is also evidence of an oscillatory variation in the rate with a period of about 14 centuries.

scholarly journals II. Of the figure of the Earth and the variation of gravity on the surface.

1735 ◽  
Vol 39 (438) ◽  
pp. 98-105 ◽  
Keyword(s):  
Centrifugal Force ◽  
The Earth ◽  
Figure Of The Earth ◽  
Rotation Of The Earth ◽  
Diurnal Rotation

The centrifugal force arising from the diurnal rotation of the Earth, depresseth it at the poles, and renders it protuberant at the Equator

I.—On Aggregate Deposits, and their Relations to Zones

1898 ◽  
Vol 5 (11) ◽  
pp. 481-488
Author(s):  
J. F. Blake
Keyword(s):  
The Sun ◽  
Geological Time ◽  
The Earth ◽  
Rotation Of The Earth

Geological time, like all other kinds of time, can only be measured by the succession of events. If the events considered are constant in their recurrence and uniform in their nature, their number will afford the means of measuring the length of time. Thus the oscillations of a given pendulum, the rotation of the earth on its axis, and its revolution round the sun are sufficiently constant and uniform to afford a basis for our seconds, days, and years. Of such uniform and constantly recurring events geology affords no examples by which we could measure the length of geological time.

scholarly journals Heraclides of Pontus on the Soul

2019 ◽  
Vol 13 (1) ◽  
pp. 349-357
Keyword(s):  
Philosophy Of Nature ◽  
Literary Genres ◽  
Literature History

Heraclides of Pontus (c. 388–310 BCE), a Platonic philosopher, worked in various literary genres. He discussed such typical Platonic topics as the transmigration of the soul, composed philosophical lives, dialogues or treaties about politics, literature, history, geography, etc., and wrote a series of works on astronomy and the philosophy of nature. Nothing is preserved. The present publication contains a collection of the testimonies about Heraclides’ lost psychological and eschatological writings. The evidences are translated and numbered according to a new edition by Schütrumpf et al. 2008.

scholarly journals Heraclides of Pontus on pleasure

2020 ◽  
Vol 14 (2) ◽  
pp. 728-741
Keyword(s):  
Philosophy Of Nature ◽  
Literary Genres ◽  
Literature History

Heraclides of Pontus (c. 388–310 BCE), a Platonic philosopher, worked in various literary genres. He discussed such typical Platonic topics as the transmigration of the soul, composed philosophical lives, dialogues or treaties about politics, literature, history, geography, etc., and wrote a series of works on astronomy and the philosophy of nature. Nothing is preserved. The present publication contains a collection of scant doxographic testimonies about Heraclides’ lost ethical and political writings. The evidences are translated and numbered according to a new edition by Schütrumpf et al. 2008.

Astronomical Influences on Biomagnetic Activity Some 120 MA ago: the Potential for Estimating the Evolution of Ancient Planetary Orbits within the Solar System

1997 ◽  
Vol 161 ◽  
pp. 245-252
Author(s):  
Donald H. Tarling ◽  
Bruno D’argenio ◽  
Marina Iorio
Keyword(s):  
Magnetic Properties ◽  
Biological Activity ◽  
Solar System ◽  
Geomagnetic Field ◽  
Sedimentary Rocks ◽  
The Sun ◽  
The Earth ◽  
Geological Past ◽  
Planetary Orbits ◽  
Rotation Of The Earth

AbstractStudies of the magnetic properties of sedimentary rocks provide a record of biological activity in the geological past of the Earth. There is increasing evidence that the rate of biological activity reflects, in part, the direct and indirect influence of the Earth’s orbit around the Sun. These orbital changes also influence the strength and direction of the geomagnetic field, showing that orbital changes directly affect the processes generating the geomagnetic field. Therefore the presence of these effects means that past changes in the Earth’s orbit and the rate of rotation of the Earth can be investigated from such geological and geophysical records.

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