In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

John David Jackson ( January 19 , 1925 – May 20 , 2016 ) was a Canadian – American physics .
John David Jackson ( January 19 , 1925 – May 20 , 2016 ) was a Canadian – American physics professor emeritus at the University of California , Berkeley and a faculty senior scientist emeritus at Lawrence Berkeley National Laboratory .