from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A representation of a sphere or part of a sphere on a plane surface.
- n. Astronomy A polar projection of half or more of the celestial sphere on a chart equipped with an adjustable overlay to show the stars visible at a particular time and place.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any representation of part of a sphere on a plane surface
- n. Any of several charts of the celestial sphere having an overlay or window that may be adjusted to show the stars visible at a particular time, or from a particular place
from the GNU version of the Collaborative International Dictionary of English
- n. The representation of the circles of the sphere upon a plane; especially, a representation of the celestial sphere upon a plane with adjustable circles, or other appendages, for showing the position of the heavens, the time of rising and setting of stars, etc., for any given date or hour.
from The Century Dictionary and Cyclopedia
- n. A projection of the sphere; especially, a polar projection of the celestial sphere
- n. An apparatus consisting of a polar projection of the heavens, with a card over it turning about the pole, and so cut out as to show the part of the heavens visible at a given latitude at a given local sidereal time.
Sorry, no etymologies found.
A planisphere is a visual aid to astronomers and stargazers.
A planisphere is a small thing that I can just leave tucked in with my maps in my car and anytime I'm out doing a star party or I'm at a friend's for a barbeque and they're like, "hey, what's that object?"
"planisphere," because it can be made to show all the constellations visible at a given time at a given date, and no others.
The planisphere must have been a marvel to the men who first set eyes on it in year 548 of the Hijrah—or 1154 in the calendar of Christian kings: a perfect disk of solid silver, close to two meters in diameter, and weighing as much as two men.
A medical text in Arabic written by a Jewish doctor living in Tunisia in the early 900s explains that, two hundred years before al-Idrisi created his silver planisphere, itriyya already meant long thin strands of dried dough that were cooked by boiling.
The execution of Philip of Mahdiyah happened at the very time when engravers were at work on the silver planisphere, and al-Idrisi was bringing his decade and a half of study to an end by writing A Diversion for the Man Longing to Travel to Far-Off Places.
The silver planisphere is a sorry symbol of how much of the cultural legacy of Muslim Sicily has been destroyed.
Al-Idrisi interviewed these polyglot traders as he labored to create the planisphere.
It contained information on the customs, products, commerce, language, and character of all the locations on the planisphere.
Their motive, if this theory is correct, was that al-Idrisi worked for an infidel: he was commissioned to create the planisphere by King Roger II.