A Treatise on Spherical AstronomyUniversity Press, 1908 - 506 pàgines |
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Frases i termes més freqüents
a₁ aberration angular approximately ascending node assume Astronomy axis azimuth celestial sphere clock Coll constant coordinates corresponding cos² cosec culmination d₁ decl determined direction diurnal diurnal motion earth eccentricity ecliptic ephemeris equation equatorial equinox error Exam expression follows formula geocentric given graduated great circle Greenwich mean Hence horizon horizontal parallax hour angle instrument interval known latitude Math mean distance mean longitude mean noon measured meridian circle moon moon's motion nole nutation obliquity observer obtain parallel perpendicular planet point of Aries pole position angle precession quantities R₁ R₂ radius refraction respectively right ascension rotation seconds of arc semi-diameter Show sidereal day sin² solstice spherical star Substituting sun's supposed t₁ tan² tangent telescope transit triangle Trip true true anomaly velocity Venus whence zenith distance zero
Passatges populars
Pàgina 147 - Newton generalized the law of attraction into a statement that every particle of matter in the universe attracts every other particle with a force which varies directly as the product of their masses and inversely as the square of the distance between them; and he thence deduced the law of attraction for spherical shells of constant density.
Pàgina 146 - LAW I. Every body continues in its state of rest, or of uniform motion in a straight line, except in so far as it may be compelled to change that state by impressed forces.
Pàgina 301 - The squares of the periodic times of the planets are proportional to the cubes of their mean distances from the sun.
Pàgina 146 - Change of motion is proportional to the impressed force and takes place in the direction of the straight line in which the force acts.
Pàgina 496 - ... the ratio of the velocity of the Earth in its orbit to the velocity of light, might not need correction or modification.
Pàgina 244 - The space comprehended between the Tropic of Cancer and the Arctic Circle is the North Temperate Zone; and the similar space between the Tropic of Capricorn and the Antarctic Circle is the South Temperate Zone.
Pàgina 146 - To every action there is always an equal and contrary reaction ; or, the mutual actions of any two bodies are always equal and oppositely directed in the same straight line.
Pàgina 145 - Kepler, and is expressed by his second law, which is thus stated:— In the motion of a planet round the sun, the radius vector, drawn from the centre of the sun to the planet, sweeps over equal areas in equal times.
Pàgina 238 - We shall suppose that t is the part of the equation of time due to the obliquity of the ecliptic, and t
Pàgina 427 - Up to now we have been explaining to the best of our ability the revolutions of the Earth around the sun and of the moon around the Earth.