In 1929, the Soviet Union introduced the 'continuous week': a five-day cycle with one day off, assigned to each worker on a rota and often marked by a colour. The goal was to keep factories running nonstop and weaken the religious Sunday rest. The downside: members of the same family often no longer shared a day off. By 1931 the system had moved to six days, before the seven-day week returned in 1940.
That's the estimate from a WHO-led study published in The Lancet in 2024, covering the half-century since the Expanded Programme on Immunization was launched in 1974. It works out to about six lives saved every minute, mostly infants. The measles vaccine alone accounts for around 60% of those lives.
According to the World Gold Council, about 216,000 tonnes of gold have been mined in all of human history. Because gold is so dense (19.3 tonnes per cubic metre), it would fit in a cube about 22 metres on each side, roughly the height of a seven-storey building. Strikingly, about two-thirds of it has been mined since 1950.