A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Why is the data arranged in a spiral pattern?
Ah, so.. unanswerable

By the time of John Seller's Atlas Maritima of 1670, "India Beyond the Ganges" had become "the East Indies" including China, Korea, southeast Asia and the islands of the Pacific in a map that was every bit as distorted as Ptolemy's, despite the lapse of approximately 1500 years. That "east" in turn was only an English translation of Latin Oriens and Orientalis, "the land of the rising sun," used since Roman times for "east." The world map of Jodocus Hondius of 1590 labels all of Asia from the Caspian to the Pacific as India Orientalis, shortly to appear in translation as the East Indies.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When was John Seller's Atlas Maritima?
Ah, so.. 1670

In the 16th century the northern fringe of the Sahara, such as coastal regencies in present-day Algeria and Tunisia, as well as some parts of present-day Libya, together with the semi-autonomous kingdom of Egypt, were occupied by the Ottoman Empire. From 1517 Egypt was a valued part of the Ottoman Empire, ownership of which provided the Ottomans with control over the Nile Valley, the east Mediterranean and North Africa. The benefit of the Ottoman Empire was the freedom of movement for citizens and goods. Trade exploited the Ottoman land routes to handle the spices, gold and silk from the East, manufactures from Europe, and the slave and gold traffic from Africa. Arabic continued as the local language and Islamic culture was much reinforced. The Sahel and southern Sahara regions were home to several independent states or to roaming Tuareg clans.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What key feature made Algeria a vital part of the Ottoman empire?
Ah, so..
unanswerable