Prophet Muhammad died in 632 AD. One of his messages was to make pilgrimage to Mecca. So, his followers, or Muslims, needed maps and travel guides to make this pilgrimage, corresponding to the increased demand for these tools in Islamic countries.
It´s because of the lack of the gravity factor that´s present on the surface of Earth. This makes bodies and objects so light and they practically float in the station´s interior. Earth´s gravity is simply weaker the further you are from it.
