بِسْمِ اللهِ الرَّحْمٰنِ الرَّحِيْمِ
GPS today uses electricity and satellite communication for its operation but have you ever thought how one could navigate though wilderness and in travelling without it, it seems really tough task but for completion of this tough task people of past have astrolabe with them.
There are proofs of other technologies too but as for this blog post information related to Astrolabe is available. Astrolabe in the past had helped people to navigate through seas and lands, for positioning, time of prayers a compass and much more even a number historians says it was the smartphone of the past.
Astrolabe was later replaced by much advance technology, still it has its own legend today. Astrolabe founded in ancient time and later additions were made.
Note- Above is a example of Nautical astrolabe but not every astrolabe looks like this.
Astrolabes were having a size which made them portable. They were made of different materials but only metal ones still remains if there were wooden astrolabes they should had been perished a long ago.
In day time they took measurements from the sun and at night from the stars especially constellation they help people to find their position over the planet. The measurements taken from the astrolabe are really precise and amazes one even the scientist of today.
Astrolabe provides one with a plane image of the celestial sphere and the principal circles. Astrolabe can also be considered as a analog computer providing a range of features.
Astrolabes can be used in both ways for astronomical which means study of aspect of universe in practical way and astrological way which is zodiac signs and much more now considered as non scientific but in past people used these techniques for finding weather conditions.
It was used in Muslim world as well as medieval Europe, Mariners also used it but later was replaced by sextant.
A typical astrolabe was made of brass or iron and was of size ranging from (3 to 18 inches).
It has many parts which connected make an astrolabe: a base plate (the mater) with a network of lines representing celestial coordinates; an open pattern disk (the rete) with a map of stars, including the aforementioned circles, that rotated on the mater around a centre pin corresponding to the north celestial pole; and a straight rule (the alidade), used for sighting objects in the sky.
The alidade made it possible to use astrolabe for surveying.
I was thinking of typing how the astrolabe works but it is very difficult to understand it by reading so one can watch it over YouTube i prefer the video uploaded by Ted Ed.
Note- History is precised and not accurate.