ABSTRACT

It was built purely to serve.—George Bernard ShawToday, using GPS receivers133 to go from one place to another on water or on land and surly arrive there one cannot imagine how people could have navigated from one location to another on oceans or on big lakes, utilizing manpower or wind and sails, without knowing exactly where they were, not having accurate or even inaccurate maps, and not knowing where the rocks, or shoals are? But obviously they did, and in most cases successfully and in few cases they perished. The first attempt of mankind to guide ships through dangerous waters into a safe harbor was the Lighthouse of Alexandria (Egypt), built between 280 and 247 BC on the ancient island of Pharos. This lighthouse was considered one of the seven wonders of the ancient world. The height was estimated to have been between 393 and 450 ft. (120 and 149 m). We can 133See Chapter 26, Space Applications in Everyday Life.