Tech feed
405 nm
Blu-ray uses a blue-violet laser with a wavelength of about 405 nanometres to read its discs. The shorter wavelength helps its optical system distinguish more densely packed information than a DVD can.
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.