A Gravesend Grammar student who went on to become a nuclear physicist at Harvard University has died at the age of 76.

Dr Leonard Keith Sisterson was educated at the Church Walk school before going on to study at Cambridge University and London’s Imperial College where he gained his Ph.D. in nuclear physics.

In 1965, he married course mate Janet and moved to Massachusetts, USA, where he took up a job in Harvard University’s physics department before going on to work in machine intelligence and signal processing for several organisations in the state.

Dr Sisterson, previously of Read Way, Gravesend, retired in 2007 allowing him to concentrate on his hobbies.

He was a lover of classical music, spending most of his adult life playing piano and taking lessons for the past seven years, and was an amateur wine merchant.

Sailing was another passion of his and he had a 19-foot boat, was a member of a yacht club and enjoyed captaining tall ships in the Caribbean.

He was also president of The Nauset Light Preservation Society, a group which focused on conserving a famous lighthouse in his home town of Eastham, and captain of the local neighbourhood watch.

Six years after his retirement he founded Cape Cod Music Apps, which made apps to help with musical education.

In his younger days, he was an avid camper, hiker, cross-country skier, beer brewer and hockey fan.

His brother, David, said Leonard, known as Keith, had always shown an aptitude for science.

He said: “My aunt told me when Keith was 15 and she asked him what he wanted to do as a job when he said he wanted to be a physicist.

“He was a very good older brother to have and always helped me out especially when it came to homework. He will certainly be sorely missed.”

Keith and his family moved to Gravesend when his father, Len, took up a job as a River Thames pilot guiding in larger boats.

He and Janet, originally from Edinburgh, moved to America when opportunities in their respective fields emerged — Janet worked in medical physics specialising in cancer.

He passed away on Thursday, May 3, at hospital in Cape Cod, Massachusetts.

He is survived by his wife of 52 years, Janet, his brother David Sisterson and aunt Margaret McLelland, both of Gravesend, his children, Jim and Mark and three grandchildren, Rylie, Bailey and Rafi.