History of Astronomy |
From inside the book
Results 1-5 of 11
Page 27
He adopted the excentric and equant of Hipparchus to explain the unequal
motions of the sun and moon. He adopted the epicycles and deferents which had
been used by Apollonius and others to explain the retrograde motions of the
planets.
He adopted the excentric and equant of Hipparchus to explain the unequal
motions of the sun and moon. He adopted the epicycles and deferents which had
been used by Apollonius and others to explain the retrograde motions of the
planets.
Page 28
This way of looking at the apparent motions shows why each planet, when
nearest to the earth, seems to move for a time in a retrograde direction. The
attempts of Ptolemy and others of his time to explain the retrograde motion in this
way were ...
This way of looking at the apparent motions shows why each planet, when
nearest to the earth, seems to move for a time in a retrograde direction. The
attempts of Ptolemy and others of his time to explain the retrograde motion in this
way were ...
Page 32
It would also explain the retrograde motion of planets when in opposition. We
must here notice that at this stage Copernicus was actually confronted with the
system accepted later by Tycho Brahe, with the earth fixed. But he now recalled
and ...
It would also explain the retrograde motion of planets when in opposition. We
must here notice that at this stage Copernicus was actually confronted with the
system accepted later by Tycho Brahe, with the earth fixed. But he now recalled
and ...
Page 33
It is true that neither the Pythagorean nor the Egypto-Tychonic system required
epicycles for explaining retrograde motion, as the Ptolemaic theory did.
Furthermore either system could use the excentric of Hipparchus to explain the
irregular ...
It is true that neither the Pythagorean nor the Egypto-Tychonic system required
epicycles for explaining retrograde motion, as the Ptolemaic theory did.
Furthermore either system could use the excentric of Hipparchus to explain the
irregular ...
Page 34
Moreover, observers had found irregularities in the moon's motion, due, as we
now know, to the disturbing attraction of the ... Copernicus made this rotation of
the earth's axis about the pole of the ecliptic retrograde * Kepler tells us that
Tycho ...
Moreover, observers had found irregularities in the moon's motion, due, as we
now know, to the disturbing attraction of the ... Copernicus made this rotation of
the earth's axis about the pole of the ecliptic retrograde * Kepler tells us that
Tycho ...
What people are saying - Write a review
We haven't found any reviews in the usual places.
Other editions - View all
Common terms and phrases
accurate Airy ancient Astronomer Royal astronomical units bright calculations Cape catalogue centre century Chaldaeans Chinese comet Copernicus diameter discovered discovery earth Egyptian epicycles equatorial error excentric explain fact fixed stars Galileo Greenwich Halley heavenly bodies heavens heliometer Hipparchus History of Astronomy Huggins instruments JOHANNEs KEPLER John Herschel Jupiter Jupiter's Kepler Laplace Lick Observatory light line of apses line of sight lunar Mars mathematical mean distance measured ment Mercury meteor miles a second moon nebulae Newton º º observations Observatory orbit parallax period photographic physical planet planetary pole position predicted proper motion proved Ptolemy R. S. Phil records refractor retrograde retrograde motion revolving round ring rotation satellites Saturn seems showing Sir William Herschel Sirius solar eclipse solar system spectra spectroscope spectrum sphere spots stellar sun-spot supposed tables telescope theory tion Trans Tycho Brahe universal gravitation Uranus velocity Venus Verrier
Popular passages
Page 67 - that every particle of matter in the universe attracts every other particle, with a force whose direction is that of the line joining the two, and whose magnitude is directly as the product of their masses, and inversely as the square of their distances from each other.
Page 26 - So he sate and cunningly guided the craft with the helm, nor did sleep fall upon his eyelids, as he viewed the Pleiads and Bootes, that setteth late, and the Bear, which they likewise call the Wain, which turneth ever in one place, and keepeth watch upon Orion, and alone hath no part, in the baths of Ocean. This star, Calypso, the fair goddess, bade him to keep ever on the left as he traversed the deep.
Page 53 - The third, viz. that the squares of the periodic times are proportional to the cubes of the mean distances...
Page 79 - Wherefore if according to what we have already said it should return again about the year 1758, candid posterity will not refuse to acknowledge that this was first discovered by an Englishman.
Page 122 - ... They have not been regarded as so successful as his geometrical analysis of the observed phenomena. It is only just to add that he himself did not attach equal weight to them ; for in answer to objections urged by Lalande to his theory that the spots are depressions, Wilson wrote thus in 1783 : — ' Whether their first production and subsequent numberless changes depend upon the eructation of elastic vapours from below, or upon eddies or whirlpools commencing at the surface, or upon the dissolving...
Page 51 - He then said boldly that it was impossible that so good an observer as Tycho could be wrong by eight minutes* and added, " out of these eight minutes we will construct a new theory that will explain the motions of all the planets.
Bibliographic information
| Title | History of Astronomy Hist. of sci. series History of the sciences |
| Author | George Forbes |
| Publisher | Putnam, 1909 |
| Original from | the University of California |
| Digitized | 29 Nov 2007 |
| Length | 200 pages |
| Export Citation | BiBTeX EndNote RefMan |