Thirty-One Satellites and a Greek Islander: How GPS Actually Works
· 12 min read
There are, at this very moment, thirty-one satellites circling the Earth at an altitude of 20,200 kilometres. They do nothing but broadcast the time. This is, by any reasonable standard, an extravagant use of orbital real estate, and yet I must concede (while relighting my pipe, which tends to go out during moments of intellectual generosity) that without them, your hiking watch would be little more than an expensive bracelet with aspirations.