III—Interplanetary Navigation

1955 ◽  
Vol 8 (1) ◽  
pp. 35-40
Author(s):  
J. G. Porter
Keyword(s):  
Dead Reckoning ◽  
Difficult Problem ◽  
Base Line ◽  
The Sun ◽  
Space Navigation ◽  
Simple Matter ◽  
The Earth ◽  
The Subject ◽  
The One ◽  
Interplanetary Navigation

Most people know something about space ships nowadays, and probably think that navigation in space is quite a simple matter; at any rate, it is a subject that is glossed over very briefly in most books on the subject. In my view, space navigation is not a simple matter, and it has certainly not received the attention it deserves. Navigation on the Earth is easy, because of the one important fact that you are on the surface of the Earth. A couple of sights, measuring the angles from two stars down to the horizon, together with the azimuths of the stars and the distance from the centre of the Earth, will give an exact statement of position. But out in space there is no Earth, no horizon—in fact nothing whatever to use as a basis of measurement. Clearly then, two angles are not enough; a third one is needed, to give a sort of tripod of sights—two of the legs being anchored to two planets (or the Sun and a planet) because their positions in space at any time are known, and the distance between them can be used as a base-line. The solution of all the triangles involved is indeed a difficult problem, but there is also the impossibility of making three simultaneous observations. It might be thought that one could do as at sea and take one sight followed later by others, making allowance for the motion of the ship in the intervals. However, this involves the idea of dead reckoning, which, although a useful concept at sea, is quite impossible to apply in space, as the following example shows.

scholarly journals Exeter Book Riddle 95: ‘The Sun’, a New Solution

2019 ◽  
Vol 137 (4) ◽  
pp. 612-638
Author(s):  
Dieter Bitterli
Keyword(s):  
Tenth Century ◽  
Exeter Book ◽  
The Sun ◽  
Anglo Saxon ◽  
The Past ◽  
The Earth ◽  
English Verse ◽  
Isidore Of Seville ◽  
The Subject ◽  
The One

Abstract Elusive and fraught with textual difficulties, Riddle 95, the ‘last’ of the Old English verse riddles preserved in the tenth-century Exeter Book, has long baffled modern readers as one of a handful of thorny items in the collection that have so far defied solution. ‘Book’ is the answer that has found most acceptance with critics in the past, yet the speaking subject of Riddle 95 is unlike anything described in those items of the collection that actually deal with writing and the tools of the monastic scriptorium. Rather, the linguistic and thematic parallels between Riddle 95 on the one hand, and the cosmological riddles and poems in the Exeter Book on the other, strongly suggest that the subject of Riddle 95 is the sun, a frequent topic of early medieval enigmatography. The poem obliquely relates how the rising sun installs itself in the sky to shed its welcome light upon the earth before it sets and vanishes from sight, completing its daily orbit along unknown paths. The main clues helping to secure the solution ‘sun’ are based upon what was known in Anglo-Saxon England about the solar course and the planetary motions, especially from the astronomical writings of Isidore of Seville and Bede. Further evidence is provided by several analogues in the Anglo-Latin riddle tradition, including the Enigmata of Aldhelm and his followers.

Dombey and Son

2008 ◽  
Author(s):  
Charles Dickens ◽  
Dennis Walder
Keyword(s):  
Family Relationships ◽  
The Sun ◽  
The Novel ◽  
The Earth ◽  
The Future ◽  
Original Illustrations ◽  
The One

Dombey and Son ... Those three words conveyed the one idea of Mr. Dombey's life. The earth was made for Dombey and Son to trade in, and the sun and moon were made to give them light.' The hopes of Mr Dombey for the future of his shipping firm are centred on his delicate son Paul, and Florence, his devoted daughter, is unloved and neglected. When the firm faces ruin, and Dombey's second marriage ends in disaster, only Florence has the strength and humanity to save her father from desolate solitude. This new edition contains Dickens's prefaces, his working plans, and all the original illustrations by ‘Phiz’. The text is that of the definitive Clarendon edition. It has been supplemented by a wide-ranging Introduction, highlighting Dickens's engagement with his times, and the touching exploration of family relationships which give the novel added depth and relevance.

scholarly journals XIII. On the precession of a viscous spheroid, and on the remote history of the Earth

1879 ◽  
Vol 170 ◽  
pp. 447-538 ◽  
Keyword(s):  
Relative Motion ◽  
Mass Motion ◽  
The Sun ◽  
The Earth ◽  
Bodily Tides ◽  
History Of ◽  
The Subject ◽  
Theoretical Dynamics

The following paper contains the investigation of the mass-motion of viscous and imperfectly elastic spheroids, as modified by a relative motion of their parts, produced in them by the attraction of external disturbing bodies; it must be regarded as the continuation of my previous paper, where the theory of the bodily tides of such spheroids was given. The problem is one of theoretical dynamics, but the subject is so large and complex, th at I thought it best, in the first instance, to guide the direction of the speculation by considerations of applicability to the case of the earth, as disturbed by the sun and moon.

scholarly journals XII.—On Dust, Fogs, and Clouds

1881 ◽  
Vol 30 (1) ◽  
pp. 337-368 ◽  
Author(s):  
John Aitken
Keyword(s):  
The Other ◽  
Close Connection ◽  
Fair Weather ◽  
Human Interest ◽  
The North ◽  
The Earth ◽  
Regular Succession ◽  
The Subject ◽  
Successive Season ◽  
The One

Water is perhaps the most abundant and most universally distributed form of matter on the earth. It has to perform more varied functions and more important duties than any other kind of matter with which we are acquainted. From its close connection with all forms of life, it has been the subject of deepest interest in all ages. It is constantly changing from one of its states to another. At one time it is solid, now liquid, and then gaseous. These changes take place in regular succession, with every return of day and night, and every successive season; and these changes are constantly repeating themselves with every returning cycle. Of these changes, the one which perhaps has the greatest interest for us, and which has for long ages been the subject of special observation, is the change of water from its vaporous state, to its condensation into clouds, and descent as rain. Ever since man first “observed the winds “and “regarded the clouds,” and discovered that “fair weather cometh out of the north,” this has been the subject of intensest human interest, and at present forms one of the most important parts of the science of meteorology, a science in which perhaps more observations have been made and recorded than in all the other sciences together.

scholarly journals THE FORGOTTEN GEOGRAPHIC AND PHYSICAL – OCEANOGRAPHIC KNOWLEDGE OF THE PREHISTORIC GREEKS

2017 ◽  
Vol 43 (1) ◽  
pp. 92 ◽  
Author(s):  
I.D Mariolakos
Keyword(s):  
Atlantic Ocean ◽  
Relative Position ◽  
British Isle ◽  
The Sun ◽  
Greek Mythology ◽  
The West ◽  
The Earth ◽  
The Subject ◽  
Greek Myths

Many believe that the Greek Mythology is a figment of the vivid imagination of the ancient Greeks. Consequently, the Greek Myths are all fantastic stories. In my opinion, this view is erroneous, at least on the subject concerning the geographic and physical-oceanographic characteristics of the Atlantic Ocean, as these were described mainly by Homer, Hesiod, the Orphics and Plutarch. In the present paper (i) some of the references made by the above mentioned authors are selectively reported, and (ii) the physical and geological validation is given, based on the present-day scientific views and knowledge. Namely, the prehistoric Greeks knew about the Hyperboreans, the island of Ierne (Ireland), the British isle etc., by the Orphics. From the writings of Plutarch, they knew (i) the relative position of the present-day Iceland (Ogygia) and its distance from Britain, (ii) that to the west of Iceland, three other islands are located, where the sun sets for only an hour a day, (iii) that further to the west there is a “great continent”, which surrounds the Ocean and more. Homer and Hesiod wrote that (i) the Ocean is a “river” that flows continuously, (ii) that this river encircles the Earth and (iii) that its flow is turbulent not only on the surface, but in depth as well. Unfortunately, all this knowledge was gradually forgotten by all. This is the reason why Odyssey is considered just an entertaining poem and Ulysses’ nostos a fantastic story, with no trace of historic reality.

VI. The Sun as a Star

1988 ◽  
Vol 20 (1) ◽  
pp. 102-106
Author(s):  
L.E. Cram
Keyword(s):  
Time Scales ◽  
Spatial Extent ◽  
The Sun ◽  
Distinguishing Characteristic ◽  
X Ray ◽  
Spatially Resolved ◽  
Solar Observations ◽  
The Earth ◽  
The Subject

Studies of the global (spatially unresolved) output from the sun are important for two main reasons: (1) the global solar output directed towards the earth plays a central role in solar-terrestrial relations, and (2) global solar observations form a link between (neccessarily) global observations of stars and the more refined spatially resolved observations which are available for the sun. This report covers both aspects (insofar as they concern the sun), using the time-scales of various phenomena as a basic distinguishing characteristic. Note that certain studies of spatially unresolved solar output have not been discussed, since they are actually directed toward the investigation of phenomena of strictly limited spatial extent [e.g. radiospectrograph observations (e.g. Wiehl et al. 1985) and studies of X-ray bursts (e.g. Thomas et al. 1985)]. Collections of relevant papers may be found in De Jager and Svestka (1985) and Labonte et al. (1984), while a review of germane stellar work is available in Baliunas and Vaughan (1985) and solar-terrestrial work in Donnelly and Heath (1985). A comprehensive summary of the subject by Hudson will appear soon in Review of Geophysics and Planetary Physics.

scholarly journals On the precession of the equinoxes

1832 ◽  
Vol 1 ◽  
pp. 253-254
Keyword(s):  
The Sun ◽  
Sir Isaac Newton ◽  
Isaac Newton ◽  
The Third ◽  
The Earth ◽  
Figure Of The Earth ◽  
The Subject

The Professor observes, that Sir Isaac Newton was the first mathematician who endeavoured to estimate the quantity of the precession from the attractive influence of the sun and moon on the spheroidal figure of the earth. His investigations relating to this subject evince the same transcendent abilities that are displayed in other parts of his Principia; but it is admitted, that, from a mistake in his process, his conclusion is erroneous. The investigations of other mathematicians in attempting the solu­tion of the same problem are arranged by the author under three general heads. The first arrive at wrong conclusions, in consequence of mistake in some part of their proceedings; the second obtain just conclusions, but rendered so by balance of opposite errors; the third approach as near the truth as the nature of the subject will admit, but, in the author’s estimation, are liable to the charge of obscurity and perplexity.

scholarly journals IX. On the tidal friction of a planet attended by several satellites, and on the evolution of the solar system

1881 ◽  
Vol 172 ◽  
pp. 491-535 ◽  
Keyword(s):  
Solar System ◽  
Central Body ◽  
The Sun ◽  
Tidal Friction ◽  
The Earth ◽  
History Of ◽  
The Subject ◽  
Complete Investigation

In previous papers on the subject of tidal friction I have confined my attention principally to the case of a planet attended by a single satellite. But in order to make the investigation applicable to the history of the earth and moon it was necessary to take notice of the perturbation of the sun. In consequence of the largeness of the sun’s mass it was not there requisite to make a complete investigation of the theory of a planet attended by a pair of satellites. In the first part of this paper the theory of the tidal friction of a central body attended by any number of satellites is considered.

Perturbations of the orbit of a satellite near to the earth

1958 ◽  
Vol 248 (1252) ◽  
pp. 55-62 ◽  
Keyword(s):  
Satellite Orbit ◽  
The Sun ◽  
The Earth ◽  
First Approximation ◽  
Different Types ◽  
Electromagnetic Effects ◽  
The Subject ◽  
The Cross ◽  
Earth’S Oblateness

The main perturbations of a satellite orbit near the earth are those caused by the earth’s oblateness and the atmosphere. Fortunately these two sources produce perturbations of quite different types, and as a first approximation they can be treated separately, though the cross-couplings would have to be evaluated in a thorough analysis of the subject. There are other perturbations to the orbit, caused by the attractions of the sun, moon and planets, by relativity effects, by the fact that the earth is not symmetrical about its axis and by electromagnetic effects; but these perturbations are expected to be small and will not be discussed here.

scholarly journals Seksualność osób niepełnosprawnych

2008 ◽  
Vol 52 (3) ◽  
pp. 213-226
Author(s):  
Antonina Ostrowska
Keyword(s):  
Difficult Problem ◽  
The Other ◽  
Personal Relationships ◽  
Sexual Life ◽  
The Social ◽  
The Disabled ◽  
The Subject ◽  
The One

The liberalisation of attitudes to sex on the one hand and the increased tolerance and acceptance of our society to the needs of the disabled on the other, provides an opportunity to articulate the problems faced by the disabled with respect to sex. However, little is said on the subject in Poland and the main way in which society views the disabled – or would like to view them – is as asexual objects which have no sensual needs. The unwillingness to face a difficult problem often deprives the disabled of the opportunity to experience intimate experiences and inter-personal relationships. The author attempts to discover what chances our disabled have of a satisfying sexual life and where the social sources of the difficulties experienced lie.

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