Kenneth Essex Edgeworth was a professional soldier who made original contributions to economics and especially to the theory of the origin of the solar system. He was born 26 February 1880 at Daramona House, Streete, Co. Westmeath. His father Thomas belonged to the junior branch of the Edgeworth family of Kilshrewly, Co. Longford.
He was educated at the Royal Military Academy at Woolwich and the School of Military Engineering at Chatham. He served with the Royal Engineers in South Africa, Somaliland, Egypt, Sudan, Chatham and Dublin . During World War I he was in charge of a Signals unit in France , was awarded the DSO. and MC and was three times mentioned in dispatches. He retired from the army in 1926 with the rank of Lieutenant-Colonel and in 1931 he became chief engineer in the Sudanese Department of Posts and Telegraphs at Khartoum. After five years in this post, he resigned and returned to Ireland to live at Cherbury, Booterstown, Co. Dublin, his parents’ former home.
In retirement, Edgeworth turned his attention to economics and theoretical astronomy. He published four books on economics and the ideas which he put forward have since been judged very progressive. However, it was theoretical astronomy that interested him most and over a 23-year period he published a score of papers and letters culminating in his book, ‘The Earth, the Planets and the Stars: Their Birth and Evolution’ (1961).
Edgeworth’s astronomical work was concerned mainly with star formation and the origin and development of the solar system. In 1943 he published a paper on ‘The Evolution of our Planetary System’ in the Journal of the British Astronomical Association where he suggested the existence of a vast reservoir of cometary material beyond the orbit of Neptune. This was seven years before Jan Oort made a similar suggestion and eight years before Gerard Kuiper presented his ideas on this topic. This reservoir of cometary material is generally known as the Kuiper Belt and the first object belonging to it was discovered in 1992 by D.C. Jewitt and J.X. Luu. Many more members of the Belt have since been detected and it is estimated that there are at least 70,000 trans-Neptunian objects with diameters greater than 100km in the radial zone extending from 30 to 50AU (Astronomical Units). These objects are confined to a thick band around the plane of the solar system.
Edgeworth died in Dublin on 10 October 1972 at the age of 92. Although he was elected to membership of the Royal Irish Academy in 1948, the full significance of his astronomical research was not recognised until 1995. He was elected a Fellow of the Royal Astronomical Society in 1903, a member of the British Astronomical Association in 1943 and he also belonged to the Institution of Electrical Engineers.