(written from a Production point of view)
English-born Dr. Robert Langridge (born 26 October 1933; age 88) was a real-world scientist, specialized in the fields of Biochemistry and Biophysics. Having worked his entire career in the academic world, he has made a single contribution to a motion picture production, which happened to be Star Trek II: The Wrath of Khan, and for which he dutifully received an official credit.
Langridge and his team were developing 3D computer graphics of molecular structures (currently understood to be a form of computer generated imagery or CGI for short) at the Computer Graphics Laboratory by the time The Wrath of Khan was in production. The groundbreaking nature of these graphics brought them contemporary renown, which was not lost on Alvy Ray Smith of the Graphics Group in 1981. Smith was discussing the breakdown of the various stages of what was to become the "Genesis Demo" with his supervisor Jim Veilleux when Smith proposed that Langridge do the initial molecular stage, as he had already suitable graphic computer models available. (Star Trek: The Magazine Volume 3, Issue 5, p. 51) Veilleux contacted Langridge in person, and he readily accepted. Little tweaking was required on his models for use in the final sequence as featured. The entire molecular sequence was constructed in Landridge's own computer software program. (; Starlog photo guidebook Special Effects, Vol. 4, p. 67)
Having never worked for the industry again, he has since then met his fifteen second motion picture fame with some mixed feelings as he has sighed in a 2005 interview to the Smithsonian Magazine, "My colleagues continue to give me a hard time for my 15 seconds of DNA graphics in Star Trek II". 
Career outside Star Trek
He was a graduate from the University of London with two titles, a BSc in Physics in 1954 and a PhD in Crystallography in 1957. For the latter he studied under Maurice Wilkins, the co-discoverer (and Nobel Price co-recipient for which) of the structure of DNA. It was at that time Langridge developed a lifelong fascination for modeling and visualizing structures of DNA in particular and molecules in general. In 1957 he emigrated to the United States, to take up a positions in Biophysics at Yale University (1957-59) and in Biology at the Massachusetts Institute of Technology (MIT, 1959-61). His drive "to visualize the invisible" led him to vigorously pursue the possibilities the first-generation IBM computers could provide to this end, as well as delving into and writing first-generation computer graphics programs.  In order to achieve this he (co-)founded his first specialized department, Project MAC (now The Laboratory for Computer Science), at MIT in 1964, something he repeated personally in 1969 with the establishment of the Computer Graphics Laboratory at Princeton University. In 1976 he moved the department to the University of California, San Francisco (UCSF), in whose employment he stayed for the remainder of his career.
Robert Langridge continued his career in academia and held the title of Professor Emeritus of Pharmaceutical Chemistry and of Biochemistry and Biophysics at the USCF at the time of his retirement in 1994, which he now enjoys with his lifelong wife Ruth and three daughters.