| 释义 |
▪ I. epicycle, n.|ˈɛpɪsaɪk(ə)l|
Forms: (4 episicle, 5 epicikle, epycikle), 6–7 epicicle, (7 epycycle), 7– epicycle.
[ad. L. epicyclus, a. Gr. ἐπίκυκλος, f. ἐπί upon + κύκλος circle.]
1. A small circle, having its centre on the circumference of a greater circle. Chiefly Astron.
In the Ptolemaic system of astronomy each of the ‘seven planets’ was supposed to revolve in an epicycle, the centre of which moved along a greater circle called a deferent. This conception, though superseded as a physical explanation, describes with approximate correctness the relative motion of a planet when the earth is assumed as fixed; and it is therefore still occasionally used for this purpose by modern astronomers.
c1391Chaucer Astrol. ii. §35 The Moone Moeuyth the contrarie from othere planetes as in hire Episicle. 1413Lydg. Pilgr. Sowle v. i. (1859) 70 In the circumference of eueriche of these cercles, was sette a lytel Cercle..which Cercle is cleped of Astronomyens the Epicikle. 1561Eden Arte of Nauig. i. xx. 22. 1571 Campion Hist. Irel. ii. vii. (1633) 97 The sun..standing still in his epicycle the space of three hours. 1613M. Ridley Magn. Bodies 41 The needle..doth turne himselfe twise about, and make two whole circles, or epicicles in this voyage. 1670Wallis in Phil. Trans. V. 2070 The Earth describes a small Epicycle about the Common Center of Gravity of the Earth and Moon. 1726tr. Gregory's Astron. I. 194 Such..as still maintained, that the Earth was Immovable, made Mercury and Venus move in Epicycles round the Sun. 1860Gen. P. Thompson Audi Alt. III. cxxii. 68 Copernicus or whoever..scattered the cycles and epicycles which had gone before.
fig.1643Sir T. Browne Relig. Med. i. §6, I love to..follow the great wheele of the Church, by which I move, not reserving any proper poles or motion from the epicycle of my owne brain. 1831Carlyle Sart. Res. (1858) 157 What infinitely larger Cycle (of causes) our little Epicycle revolves on.
2. In mod. Astron. sometimes used for: The curve described by a planet moving in an epicycle, i.e. its geocentric path.
1854Moseley Astron. liv. (ed. 4) 170 The path of the planet..will be a curve, called an Epicycle accurately.
▪ II. † ˈepicycle, v. Obs. rare—1.
[f. prec. n.]
trans. To cause to move in an epicycle.
1652Benlowes Theoph. vii. xli, Thy Law..Does epicycle their obliquely gliding Cars. |