Question: Who was the friend that Ralph Leighton wrote about in Tuva or Bust!?

Context paragraphs:
Home at Seven (film): Home at Seven is a 1952 British mystery drama film directed by and starring Ralph Richardson.  It also featured Margaret Leighton, Jack Hawkins, Campbell Singer and Michael Shepley.  It was based on the play "Home at Seven" by R. C. Sherriff.  The film remains Richardson's only work as a film director.  It follows a man who returns to his suburban home one evening to discover that he has been missing for 24 hours, despite not remembering the 'lost' day.

I Love Lisa: "I Love Lisa" is the fifteenth episode of "The Simpsons"<nowiki>'</nowiki> fourth season.  It originally aired on the Fox network in the United States on February 11, 1993.  In the episode, Lisa gives Ralph Wiggum a Valentine's Day card when she sees that he has not received any.  Ralph reads too much into Lisa's gesture and, much to Lisa's dismay, relentlessly pursues her with affection.  Lisa snaps at Ralph and angrily tells him they are not together and that she never liked him.  Heartbroken, Ralph channels his feelings into his performance as George Washington in the school's President's Day pageant.  After a thunderous applause from the audience, he is able to accept Lisa as just a friend.

Infinity (film): Infinity is a 1996 American biographical drama film about the early life of physicist Richard Feynman.  Feynman was played by Matthew Broderick, who also directed and produced the film.  Broderick's mother, Patricia Broderick, wrote the screenplay, which was based on the books "Surely You're Joking, Mr. Feynman! " and "What Do You Care What Other People Think? ", both written by Feynman and Ralph Leighton.

Ralph Leighton: Ralph Leighton ( ; born 1949) is an American biographer, film producer, and friend of the late physicist Richard Feynman.  He recorded Feynman relating stories of his life.  Leighton has released some of the recordings as "The Feynman Tapes".  These interviews became the basis for the books "Surely You're Joking, Mr. Feynman! " and "What Do You Care What Other People Think? ", which were later combined into the hardcover anniversary edition "Classic Feynman: All the Adventures of a Curious Character".  Leighton is an amateur drummer and founder of the group Friends of Tuva.  In 1990 he wrote "Tuva or Bust!  Richard Feynman's Last Journey."

Peter Hannan (producer): Peter Hannan (born August 13, 1954) is an American animator, singer-songwriter, author, illustrator, producer, artist, and entrepreneur.  Hannan is the creator, executive producer, and show runner of the Nickelodeon series "CatDog".  He also wrote and sang the "CatDog" theme song.  He has created and developed properties for numerous studios.  He works as a character designer and writes for various other animated shows.  He created a web series called "Really Freaking Embarrassing," single-panel cartoons called "The Adventures of a Huge Mouth" that ran in independent newspapers throughout the U.S., and writes and illustrates books, including "Petlandia, My Big Mouth: 10 Songs I Wrote That Almost Got Me Killed, The Greatest Snowman in the World," "Super Goofballs, Sillyville or Bust," "Escape from Camp Wannabarf," "School After Dark: Lessons in Lunacy," and "The Battle of Sillyville: Live Silly or Die!"  He has written and illustrated newspaper and magazine pieces with titles like "The Incredible Shrinking Christmas" and "The Good, the Bad, and the Irish."  He co-founded the company "FutureVision", which produced a TV concert series featuring blues legends Muddy Waters, Albert King, Buddy Guy & Junior Wells, Bobby Bland, Otis Rush, Blind John Davis, and others.  He has taught, lectured, and led art, writing, animation, and creativity workshops for pre-school through college students.  He has worked as a graphic designer and art director and done illustrations for magazines, newspapers, and advertising.  He exhibits paintings, illustrations, and cartoons.

The Holly and the Ivy (film): The Holly and the Ivy is a 1952 British drama film directed by George More O'Ferrall and produced by Anatole de Grunwald.  Adapted from a play by Wynyard Browne, it is about an English clergyman whose neglect of his grown offspring, in his zeal to tend to his parishioners, comes to the surface at a Christmas family gathering.  Ralph Richardson, Celia Johnson, and Margaret Leighton star, while Margaret Halstan and Maureen Delany reprised their roles from the stage.  It had its U.S release in 1954.

Dorothea Leighton: Dorothea Cross Leighton (September 2, 1908 – August 15, 1989) was an American social psychiatrist and a founder of the field of medical anthropology.  Leighton held faculty positions at Cornell University and the University of North Carolina and she was the founding president of the Society for Medical Anthropology.  She and her husband, Alexander Leighton, wrote "Navajo at the Door", which has been described as the first written work in applied medical anthropology.

Tuva or Bust!: Tuva or Bust!  (1991) is a book by Ralph Leighton about the author and his friend Richard Feynman's attempt to travel to Tuva.

Cleveland Tower: Cleveland Tower is a tower and carillon on the campus of Princeton University.  Inspired by Boston College's Gasson Hall, the Ralph Adams Cram design is one of the defining architectural features of the Collegiate Gothic Graduate College.  The tower was built in 1913 as a memorial to former university trustee and U.S. President Grover Cleveland.  A bust of the former president is the centerpiece of the grand chamber at the tower's ground level.

The Passionate Stranger: The Passionate Stranger (U.S.  A Novel Affair) is a 1957 British drama film, directed by Muriel Box and starring Margaret Leighton and Ralph Richardson.  It uses the film within a film device, with the "real" part of the plot shot in black-and-white and the "fictional" element in colour.  The interior scenes were shot at Shepperton Studios, with location filming taking place at Chilworth, Surrey.

Supporting paragraphs: Ralph Leighton Tuva or Bust!
Answer: Richard Feynman