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Predicted upper region of the chart of nuclides (island of stability circled); darker shades indicate longer half-lives.

The island of stability in nuclear physics is a predicted set of isotopes of superheavy elements whose half-lives may be considerably longer than those experimentally observed for these elements. Its theoretical existence is attributed to stabilizing effects of closed nuclear shells and magic numbers of protons and neutrons. The island of stability is generally thought to center near copernicium and flerovium isotopes with around 184 neutrons, separated from known stable and long-lived nuclides. While stabilizing effects are expected to be greatest for nuclides with around 114 protons, other islands of stability might also exist around heavier nuclides with higher magic numbers. Estimates of the stability of elements on the island are usually around a half-life of minutes or days, with some estimates of up to millions of years. The synthesis of nuclides with up to 118 protons and 177 neutrons has demonstrated a slight stabilizing effect supporting the island's existence. (Full article...)

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On this day

March 21: Galactic Tick Day (2020)

Painting depicting the victims of the Sharpeville massacre

1556 – Archbishop of Canterbury Thomas Cranmer, one of the founders of Anglicanism, was burnt at the stake in Oxford, England, for heresy.
1814 – War of the Sixth Coalition: At the Battle of Arcis-sur-Aube, Napoleon suddenly realized his army was vastly outnumbered and hurriedly ordered a retreat.
1937 – The papal encyclical Mit brennender Sorge, condemning antisemitism and criticizing Nazism, was read from the pulpits of all German Catholic churches.
1960 – Police in Sharpeville, South Africa, opened fire on a group of unarmed black demonstrators (depicted) who were protesting pass laws, killing almost 70 people and wounding about 180 others.
1980 – Dallas aired its "A House Divided" episode, which led to eight months of international speculation regarding "Who shot J.R.?"

Ælla of Northumbria (d. 867) · Evelina Haverfield (d. 1920) · Wolfgang Wagner (d. 2010)

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Yekaterina Skudina (born 21 March 1981) is a Russian world champion and Olympic sailor. She was awarded the Roy Yamaguchi Memorial Trophy for winning the world championships in the women's Snipe class in 1998, and the bronze medal at the Yngling open world championships in 2007. At the 2011 World Championships, Skudina finished fourth in the Elliott 6m class. In addition, she has competed in three Olympic Games, finishing eighth in the Yngling class in 2004, sixth in the same class in 2008, and fourth in the Elliott 6m class in 2012.

This photograph of Skudina, taken in 2009, is part of a collection of 500 images of Russian sportspeople released to Wikimedia Commons by Bolshoi Sport.

Photograph credit: Platon Shilikov

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