Hobbies And Interests
Astrolabe
The astrolabe was first developed around the first or second century in the area of Alexandria in Greece. By the fourth century they became standardized in their construction and advanced greatly under Arab invention. An astrolabe is handheld and used to determine time and direction, locations of stars, and astronomical calculations such as when sunrise and sunset would occur. An astrolabe is comprised of several plates which are interchangeable each with coordinates for different latitudes. The plates or discs set in the face of the astrolabe pointers on the top plate would indicate the positions of the brightest 22 stars. The top plate would rotate to show where the stars would appear at different times. Muslim astronomers used the astrolabe to determine the location of Mecca and to set prayer times.
Quandrant
Early sailors improved on the crude stick used for sighting the night sky by creating the quadrant. Quadrants are quarter-circles which have degrees marked off and a sighting arm to measure stars' locations. Later quadrants were replaced by sextants, which means a sixth of a circle. Astronomers made use of quadrants to produce maps of the stars and planets. Sextants were used by navigators up until the invention of electronic positioning systems in the late 20th century.
Observatories
Observatories were built around the world to provide a good view of the night skies and to plot and predict the location of the stars and planets. One such place was an ancient Mayan site in Chichen Itza called the Caracol. Certain elements of the structure such as some of the windows are aligned with the position of Venus. It also is built so that on the equinoxes sunlight travels the stairway like a slithering snake. In northwest Persia or Iran, an observatory was built in 1259 in Maragha. This observatory drew astronomers from China and Spain and other far-off locations. The taller the building the more precise the astronomical measurements would be.
Armillary Sphere
Armillary spheres were made in both small and large sizes to show the location and position of celestial objects. They used rings to illustrate the circles of the sky. Danish astronomer Tycho Brahe in the 1500s built such devices with moveable rings which could be used to find the differences between two objects in space or the location of a star. The sun would be the center of the armillary sphere, and the elliptic and polar circles would surround it.