Edmond Halley (1656-1742)
Edmond Halley was born in London and received an education which allowed him to develop skills in Latin, Greek, Hebrew, and mathematical sciences. He then began studying at Queen's College, Oxford University. He published his first scientific paper at age 19, and then left his studies to conduct research on the Island of Saint Helena. Such a location was ideal because of the visibility of stars and because it was in the southern hemisphere. This allowed him to complete star charts which complemented those he had already made of the night sky in the northern hemisphere. After about four years, he returned to England where he met and built a friendship with Isaac Newton. He was appointed by King William III to command a ship to make navigational observations such as more accurately measuring the longitude and latitude of English settlements in America. Upon returning to England, he worked as a professor at Oxford.
Though he was not wealthy, Halley enabled the publishing of Newton's Principia Mathematica by both encouraging Newton and funding it from his own pocket when the Royal Society was unable to cover the cost. His other notable achievements include becoming a fellow of the Royal Society at age 21, a Savilian professor at Oxford in 1703, Astronomer Royal in 1719, and publishing about 100 works on topics ranging from astronomy to mathematics, statistics, and other sciences. He is possibly most famous for his accurate prediction of the comet named after him which he observed in 1682 and used laws of gravity to predict its reappearance in 1759, about 17 years after he passed away.
One of his main contributions to statistics was through analyzing mortality tables similar to the work of John Graunt (1620-1674). While Graunt examined data from London parish records, Halley, focused on data collected from Breslau, located in what is now western Poland. Breslau was a particularly good candidate to study because good records were kept and there were relatively small changes in population through moving in or out. He looked at life expectancy, particularly probability distributions of the number of years left in a person's life after a certain age. Such calculations are now part of actuarial science and are used to calculate premiums and payouts of life insurance.