gps

The Global Positioning System is a common illustration of a practical application of Einstein's special and general theories of relativity: To remain in sync, ground clocks must operate at 10.23GHz and satellite clocks at 10.22999999543MHz. These numbers were arrived at by using a combination of...

I've been seeing a lot of these ads recently, probably because I clicked on one of them a few months back. The headlines accompanying the ads have become increasingly incredible. Taking on an $11.2 Trillion market? Quite impressive when the entire US GDP is less than twice that at $18.5...

Any position on the surface of the world can be represented by two numbers: latitude (the north or south angle from the equator) and longitude (the east or west angle from the Prime Meridian in England). These two numbers are generally referred to as coordinates. In the past you might have said...