What is an Armillary Sphere?
An armillary sphere is a scientific model which demonstrates the workings of the celestial sphere, a concept which was historically used by astronomers and other scientists to understand the heavens. Viewing the Earth as the center of the universe, the celestial sphere consists of the objects visible from Earth. Using an armillary sphere, someone can calculate the position of something in the sky relative to an observer on Earth. This model can also be used to visually show people how the celestial sphere works. The armillary sphere is primarily viewed as a scientific curiosity today, although these devices can be used for some basic astronomical calculations. Numerous models can be seen on display in scientific museums which collect old instruments, and some people collect vintage spheres because they find them visually interesting. Like many antique scientific instruments, armillary spheres are often works of art in addition to working models, and they can vary widely in size from de
An armillary sphere is an old astronomical model, often skeletonized, used to display relationships along the principal celestial circles. Metal rings or hoops are used to represent such things as the equator, the arctic and Antarctic circles, the tropics and so on. It helped early estronomers in their quest to determine the positions of stars. Ptolemy, in his own description, used one with one sliding graduated circle inside another.
It is a navigational tool with circles made out of metal that are lined up with the sun, stars and the moon. It tells your location it was not accurate. The Portuguese made them better. They have an armillary sphere pictured on their flag. Once the more accurate sextants and chronometers were invented, people quit using armillary spheres.
Related Questions
- F-08.12: Say I was levitating in my dome and I had destroyed all the earth in the bottom half of the sphere. How much effort would I have to put into an Apportation spell to just move the dome itself?
- If the dirt under the dome is chewed away, would the dome be subject to gravity (a physical force)? Would the sphere and its occupants fall?
- What is an Armillary Sphere?
