Eating fish and chips outside an ugly bungalow café in the flat and windswept Falklands. I take a reading of my position from the unseen satellites passing somewhere over my head. My GPS receiver, a small grey plastic box, communicates with three lumps of silvery circuitry hovering 22,223 miles above the sky in their geostationary orbits
I walk back through the low houses and jeeps of Port Stanley and leave the small plastic device sitting on a stone knowing exactly where it is to within three meters.