How is it made? Global Positioning System (GPS)

Recently, after a family trip, a friend of mine decided to go back to use his old paper map in his travels and to put his GPS receiver to rest for ever. This came after a series of deceptions by this little device with the annoying automated voice and the 4" screen and the constantly lost signal, his words notmine. The latest of these deceptions was a trip from Ottawa to Niagara Falls which took a turn in the US. Admittedly, such a turn is normal especially if the GPS is programmed to take the shortest distance, except that my friend’s family did not have passports on them that day. Let us face it, if you have a GPS, you must have experienced some set backs here and there. But the times when the trip went smoothly without any wrong turn, you must have deep down appreciated the magic and ingenuity that transforms a little device into a holding hand that takes you from point A to point B , sometimes thousands of kilometers apart. It is indeed a "scary" thing to have someone watching your every move from somewhere "very high". Next time you plan a trip, read this note before and use your time on the road to try to reveal to your co-travelers (with as little mathematics as possible) the magic behind this technology. It works every time I want to put my kids to sleep on a long trip.