Tech feed
4 satellites
A conventional stand-alone GPS position fix normally requires measurements from at least four satellites. The receiver solves for three spatial coordinates and a fourth unknown: the offset of its own clock from the satellite system’s time.
1991
The camera widely remembered as the first webcam watched a coffee pot at Cambridge in 1991, initially over a local network. It became accessible through the World Wide Web in November 1993.
1964
The first mouse prototype in Douglas Engelbart’s research program was built in 1964 with a wooden body. Engineer Bill English constructed the device, which tracked movement using two perpendicular wheels.