Erosion is the process by which soil and rock are removed from the Earth's surface by natural processes such as wind or water flow, and then transported and deposited in other locations.

While erosion is a natural process, human activities have dramatically increased (by 10-40 times) the rate at which erosion is occurring globally. Excessive erosion causes problems such as desertification, decreases in agricultural productivity due to land degradation, sedimentation of waterways, and ecological collapse due to loss of the nutrient rich upper soil layers. Water and wind erosion are now the two primary causes of land degradation; combined, they are responsible for 84% of degraded acreage, making excessive erosion one of the most significant global environmental problems we face today.

Industrial agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regards to their effect on stimulating erosion. However, there are many available alternative land use practices that can curtail or limit erosion—such as terrace-building, no-till agriculture, and revegetation of denuded soils.

William Sanford "Bill" Nye (born November 27, 1955), popularly known as Bill Nye the Science Guy, is an American science educator, comedian, television host, actor, mechanical engineer, and scientist. He is best known as the host of the Disney/PBS children's science show Bill Nye the Science Guy (1993–1998) and for his many subsequent appearances in popular media as a science educator.

William Sanford Nye was born in Washington, D.C., the son of Jacqueline (née Jenkins; c. 1920–2000), a codebreaker during World War II, and Edwin Darby "Ned" Nye (died 1997), also a World War II veteran whose experience in a Japanese prisoner of war camp led him to become a sundial enthusiast. Nye is a fourth-generation Washington, D.C. resident on his father's side of the family. After attending Lafayette Elementary and Alice Deal Junior High in the city, he was accepted to the private Sidwell Friends School on a partial scholarship, graduating in 1973. He studied mechanical engineering at Cornell University, where one of his professors was Carl Sagan, and graduated with a Bachelor of Science in 1977. He was awarded an honorary doctorate by The Johns Hopkins University in May 2008. In May 2011, Nye was awarded an Honorary Doctor of Science degree from Willamette University where he was the keynote speaker for that year's commencement exercises.

Billy Blue or William Blue (c.1767 - 1834) was an Australian convict. Although Billy Blue’s place and date of birth are uncertain, convict records suggest he was born in Jamaica around 1767.

By 1796 he was living at Deptford, London, and working as a chocolate-maker and also labouring on ships on the Thames.

On 4 October 1796 he was convicted, at Maidstone, in Kent, of stealing raw sugar and sentenced to seven years transportation. After serving over four years in the convict hulks (ships used for housing criminals), he was transported to Botany Bay, Australia, in the convict ship Minorca. He was described in the ship’s records as 'a Jamaican Negro sailor', aged 29 in 1796.

He arrived in Sydney in 1801 and served out the remaining part of his sentence. In 1804, records show him living in ‘the Rocks’, then a very tough part of the city. There he met Elizabeth Williams, a 30-year-old convict from Hampshire, England, who had arrived in June 1804. On 27 April 1805, they were married at the old St. Philip's Anglican church in Sydney, where 5 of their 6 children were later christened.