Halloween has its roots in Samhain, a Celtic festival held around 1 November that marked the end of the harvest and the start of winter. Christianised as the eve of All Saints' Day, 'All Hallows' Eve', it survived in Ireland and Scotland, complete with disguises and lanterns carved from turnips. Irish and Scottish immigrants popularised it in the United States in the 19th century, where pumpkins replaced turnips. The festival later returned to Europe in its American form.
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.