The Comet, the first jet airliner, entered service in 1952. In 1954, two of them broke apart in flight. The investigation found that metal fatigue, caused by repeated pressurisation, had started cracks near sharp-cornered openings, where stress concentrates. Since then, fuselage openings, windows included, have rounded corners that spread the load more evenly.
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.