European 18th-century obstetrical pioneers in Japan: a new light in the Empire of the Sun

This paper discusses measurements of the apparent diameter and parallax of the star Sirius, made in the early 18th century by Jacques Cassini, and how those measurements were discussed by other writers. Of particular interest is how other writers accepted Cassini’s measurements, but then discussed Sirius and other stars as though they were all the same size as the sun. Cassini’s measurements, by contrast, required Sirius and other stars to dwarf the sun—something Cassini explicitly noted, and something that echoed the ideas of Johannes Kepler more than a century earlier.

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Word-image interaction in the treatise “Voyage en Siberie”

6th International e-Conference on Studies in Humanities and Social Sciences: Conference Proceedings ◽

10.32591/coas.e-conf.06.14163p ◽

2020 ◽

Author(s):

Elizaveta Panova

Keyword(s):

18Th Century ◽

The Sun ◽

The Enlightenment ◽

French Art

“Voyage en Siberie” describes a journey through Russia carried out by Jean Chappe d'Auteroche to observe the passage of Venus across the Sun. Besides the description of this phenomenon the book contains the author’s travel notes and study of the Russian political, historical, geographic and military conditions in the middle of the 18th century. “Voyage en Siberie” was accompanied by the cycle of illustrations performed by Jean-Baptiste Le Prince. As these works were among the first examples of the costume images on the Russian subject, they became crucial in the career of the artist who is considered to be the creator of “Russerie” in French art. This paper discusses the nature of the text and illustrations developing according to the logic of ideas of the Enlightenment. The author intends to show that although Chappe d'Auteroche and Le Prince worked together on the book they had different visions of the problem.

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Searching for the 27-day solar rotational cycle in lightning events recorded in old diaries in Kyoto from the 17th to 18th century

Annales Geophysicae ◽

10.5194/angeo-35-1195-2017 ◽

2017 ◽

Vol 35 (6) ◽

pp. 1195-1200 ◽

Cited By ~ 1

Author(s):

Hiroko Miyahara ◽

Yasuyuki Aono ◽

Ryuho Kataoka

Keyword(s):

Time Series ◽

18Th Century ◽

Maunder Minimum ◽

Lightning Activity ◽

The Sun ◽

Rotational Period ◽

Solar Cycles ◽

Earth’S Climate ◽

Insight Into ◽

Magnetic Disturbances

Abstract. A solar rotational period of approximately 27 days has been detected in cloud and lightning activities, although the mechanism of the sun–climate connection remains unclear. In previous studies, lightning activity in Japan showed a significant signal of the solar rotational period, especially around the maxima of the decadal solar cycles. Here we analyze the time series of lightning activity in the AD 1668–1767 period, extracted from old diaries in Kyoto, Japan, and search for the signal of solar rotational cycles. The 27-day cycles were detected in the lightning data and occurred only around the maxima of the decadal sunspot cycles. The signal disappeared during AD 1668–1715, which corresponds to the latter half of the Maunder Minimum when both radiative and magnetic disturbances were thought to have been weak. These findings provide insight into the connection between solar activity and the Earth's climate.

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Australia and the Transit of Venus

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000019007 ◽

1980 ◽

Vol 4 (1) ◽

pp. 114-120 ◽

Cited By ~ 2

Author(s):

R. J. Bray

Keyword(s):

East Coast ◽

18Th Century ◽

The Sun ◽

History Of Astronomy ◽

World Science ◽

James Cook ◽

The Face ◽

History Of ◽

George Iii ◽

Living Person

The passage of the planet Venus across the face of the Sun is an astronomical spectacle which no living person is likely to have seen. The phenomenon has played an important role in the history of astronomy and in stimulating world science and geographical discovery during the 18th century. But to Australia the transit of 1769 is of truly momentous significance: during the course of an expedition to the South Seas specially organized to observe it, Lt. James Cook discovered and chartered the east coast of Australia, hoisted the English flag, and took possession in the name of King George III.

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René Descartes

Philosophy ◽

10.1093/obo/9780195396577-0031 ◽

2010 ◽

Author(s):

Justin Skirry

Keyword(s):

David Hume ◽

18Th Century ◽

17Th Century ◽

The Sun ◽

Western Thought ◽

System Building ◽

Philosophical System ◽

Late 18Th Century ◽

René Descartes ◽

Modern Era

There is no doubt that Descartes is one of the most influential and perhaps one of the most misunderstood philosophers of the modern era. In many ways, Descartes can be seen as kicking off the great era of philosophical system building at the beginning of the 17th century and continuing until David Hume destroyed these systems in one blow in the late 18th century. As the builder of a philosophical system, Descartes’s works cover just about everything under (and above) the sun, from metaphysics to physics to theology to cosmology to physiology, and, with each area intersecting with the others, raise their own set of problems and questions. An article of this sort cannot hope to cover such a range of intersecting issues that arise in Descartes’s system, since an issue in one aspect of the theory often ripples out to other, far-reaching, aspects. Accordingly, this article attempts to provide a mix of introductory essays and detailed analyses of the major issues in Descartes’s system so as to guide the reader toward a clear and even-handed understanding of this giant of Western thought.

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Chromospheric activity as a function of age in main-sequence stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900053146 ◽

1966 ◽

Vol 24 ◽

pp. 40-43

Author(s):

O. C. Wilson ◽

A. Skumanich

Keyword(s):

Main Sequence ◽

The Sun ◽

Main Sequence Stars ◽

Tentative Conclusion ◽

Chromospheric Activity ◽

General Field ◽

Large Clusters

Evidence previously presented by one of the authors (1) suggests strongly that chromospheric activity decreases with age in main sequence stars. This tentative conclusion rests principally upon a comparison of the members of large clusters (Hyades, Praesepe, Pleiades) with non-cluster objects in the general field, including the Sun. It is at least conceivable, however, that cluster and non-cluster stars might differ in some fundamental fashion which could influence the degree of chromospheric activity, and that the observed differences in chromospheric activity would then be attributable to the circumstances of stellar origin rather than to age.

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Galactic orbits of stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900105340 ◽

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.

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Seti Space Missions

International Astronomical Union Colloquium ◽

10.1017/s0252921100015372 ◽

1997 ◽

Vol 161 ◽

pp. 761-776 ◽

Cited By ~ 1

Author(s):

Claudio Maccone

Keyword(s):

Electromagnetic Waves ◽

Space Missions ◽

Gravitational Lens ◽

The Sun ◽

Space Antenna ◽

Focal Distance ◽

Large Space ◽

The Earth ◽

Space Antennas ◽

New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

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A Search for Dyson Spheres around Late-Type Stars in the Solar Neighborhood II

International Astronomical Union Colloquium ◽

10.1017/s0252921100015281 ◽

1997 ◽

Vol 161 ◽

pp. 707-709 ◽

Cited By ~ 1

Author(s):

Jun Jugaku ◽

Shiro Nishimura

Keyword(s):

Solar Neighborhood ◽

The Sun ◽

Late Type ◽

Solar Type

AbstractWe continued our search for partial (incomplete) Dyson spheres associated with 50 solar-type stars (spectral classes F, G, and K) within 25 pc of the Sun. No candidate objects were found.

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Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

International Astronomical Union Colloquium ◽

10.1017/s0252921100064630 ◽

2000 ◽

Vol 179 ◽

pp. 263-264

Author(s):

K. Sundara Raman ◽

K. B. Ramesh ◽

R. Selvendran ◽

P. S. M. Aleem ◽

K. M. Hiremath

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Magnetic Flux ◽

Ultra Violet ◽

Active Regions ◽

Morphological Properties ◽

Energy Storage And Conversion ◽

The Sun ◽

X Rays ◽

The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

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