Arab and Moslem propaganda make a grand display of the astrolabe, a device used in astronomy and in navigation by mariners, 750 years before the moon-cult of Muhammad, or Muhammadism, was created. Moslems claim that they 'invented' it and as with almost all Moslem claims, it as an entirely false one. Christians had long used the astrolabe before the rise of Muhammadism, and it was a standard feature of the Byzantine Christian navy by 500 AD.

In the mid 6^th century, Christian scientist, John Philoponus details the astrolabe in his work; “Concerning the using and arrangement of the astrolabe and the things engraved upon it” (1932) pp.61-81. [Translated by Herbert Wilson Green, d. 1933] Link

“The two straight lines on the plane surface, on which the rule lies, cutting one another in the middle, correspond to the meridian line and the horizon: of these, the one descending from above from the ring whereby we suspend the instrument corresponds to the meridian line in each zone, the other cutting it in two at right angles corresponds to the horizon. On this latter, the one corresponding to the horizon, stands a semi-circle having this line itself as its diameter. This semi-circle corresponds to the hemisphere of the heaven above the earth. This semi-circle is cut in two by the other line, that descending from the ring, which we said corresponded to the meridian line, the cutting taking place by the upper end of the line near the ring. Each of the quadrants on either side has been divided into 90 degrees, on which the index of the rule falls, and thereby we determine the meridian height above the horizon of the sun, or any other star, how many degrees each hour it has been raised above the rising or the setting horizon. The ninetieth degree indicates the Sign at the summit in the case of each House, and the first [degree] what is next to the horizon itself, whether the rising or the setting one, as the using of the instrument will teach us as we proceed. It is not the case, however, that in all astrolabes both quadrants have been divided into the ninety degrees, but only one of them, for one, whichever it happens to be, is enough for our observing. For it is possible to know by either [quadrant] how far the sun, or any other star, has been raised from the setting or from the rising horizon. But that we may find it easy to observe when the instrument is suspended with either hand, in some cases both the quadrants have been engraved.”

More than one astrolabe was in usage reflecting a history of development and adapted necessity. Astrolabes were also of different sizes and shapes, depending on where they were being used. The maturity of this presentation by Philoponus and the obvious intricate development of various forms of the astrolabe instrument, make it rather ridiculous – but unsurprising – that the culf of Muhammad would claim ownership. They do insist after all, that they invented flying and the computer.