In Britain's industrial towns in the 19th and early 20th centuries, workers had to be at the mill before dawn, and alarm clocks were scarce or unreliable. So 'knocker-uppers' did their rounds in the dark, rapping on bedroom windows with a long pole or firing dried peas at them through a pea-shooter, for a few pence a week. The trade faded away as cheap alarm clocks spread.
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.