Data on a CD is stored with an error-correcting code invented in 1960 by Irving Reed and Gustave Solomon, then shuffled along the track. A scratch therefore damages small pieces of many blocks rather than one whole block, and the player rebuilds them by calculation. An audio CD can correct gaps of about 2 mm of track. The same maths protects signals from space probes.
In 1843, inventor Alexander Bain patented a way to send images over telegraph wires using synchronized pendulums. By the 1860s, a commercial fax service was already linking cities. The telephone wasn't patented until 1876, more than three decades after that first fax patent. The fax is really a child of the telegraph age.
On 8 October 1958, in Stockholm, 43-year-old Arne Larsson received the very first implanted pacemaker. The device, designed by engineer Rune Elmqvist and implanted by surgeon Åke Senning, worked for only a few hours and had to be replaced. Larsson went on to receive more than twenty pacemakers in his lifetime. He died in 2001 aged 86, outliving both the engineer and the surgeon.