Allan MacLeod Cormack
A physicist without a doctorate who cracked the mathematical puzzle that made CT scans possible, revolutionizing medical imaging.
1924–1998 (age 74)·South African and American physicist·Birthday: February 23·The Greatest Generation
Biography
Allan Cormack’s path was as unconventional as his breakthrough. Born in Johannesburg, he studied physics and began his career there before moving to the United States. While working part-time at a Cape Town hospital in the late 1950s, he became fascinated by the problem of how to reconstruct an image of the inside of a body from X-ray measurements taken from the outside. In his spare time, and with no medical background, he derived the essential mathematical algorithms. His theoretical papers, published in 1963 and 1964, were initially met with indifference. Cormack continued his quiet academic life at Tufts University, teaching physics. It was only a decade later, when Godfrey Hounsfield built the first practical CT scanner, that the world recognized Cormack’s foundational work. Their shared Nobel Prize in 1979 was a stunning validation for a theorist who had solved a profound problem simply because it interested him.
The Greatest Generation
1901–1927
Grew up during the Depression, fought World War II, and built the postwar economic boom. Defined by shared sacrifice, institutional trust, and a belief that hard work and loyalty would be rewarded.
Allan was born in 1924, placing them squarely in The Greatest Generation. The events that shaped this generation — world wars, depression, and rapid industrialization — shaped the world they entered and the choices available to them.
#1 When Allan Was Born
The biggest hits of 1924
#1 Movie
The Sea Hawk
Allan's Life & Times
The world at every milestone
1924Born
First Winter Olympics held in Chamonix, France
President: Calvin Coolidge"It Had to Be You" — Isham Jones
1929Started school
Wall Street crashes, triggering the Great Depression
Gas: $0.21/galPresident: Herbert Hoover"Singin' in the Rain" — Cliff EdwardsBest Picture: The Broadway Melody
1937Became a teenager
Hindenburg disaster; Golden Gate Bridge opens
Gas: $0.20/galPresident: Franklin D. Roosevelt"A-Tisket, A-Tasket" — Ella FitzgeraldBest Picture: The Life of Emile Zola
1940Could drive
The Blitz: Germany bombs London
Gas: $0.18/galHome: $2,938Min wage: $0.30/hrPresident: Franklin D. Roosevelt"I'll Never Smile Again" — Tommy DorseyBest Picture: Rebecca
1942Could vote
Battle of Midway turns the tide in the Pacific
Gas: $0.20/galHome: $3,175Min wage: $0.30/hrPresident: Franklin D. Roosevelt"White Christmas" — Bing CrosbyBest Picture: Mrs. Miniver
1945Turned 21
WWII ends; atomic bombs dropped on Hiroshima and Nagasaki
Gas: $0.21/galHome: $4,600Min wage: $0.40/hrPresident: Harry S. Truman"Sentimental Journey" — Les Brown & Doris DayBest Picture: The Lost Weekend
1954Turned 30
Brown v. Board of Education desegregates US schools
Gas: $0.29/galHome: $8,925Min wage: $0.75/hrPresident: Dwight D. Eisenhower"Little Things Mean a Lot" — Kitty KallenBest Picture: On the Waterfront
1964Turned 40
Civil Rights Act signed; Beatles arrive in America
Gas: $0.30/galHome: $13,450Min wage: $1.25/hrPresident: Lyndon B. Johnson"I Want to Hold Your Hand" — The BeatlesBest Picture: My Fair Lady
1974Turned 50
Nixon resigns the presidency
Gas: $0.53/galHome: $22,600Min wage: $2.00/hrPresident: Gerald Ford"The Way We Were" — Barbra StreisandBest Picture: The Godfather Part II
1984Turned 60
Apple Macintosh introduced
Gas: $1.13/galHome: $59,800Min wage: $3.35/hrPresident: Ronald Reagan"When Doves Cry" — PrinceBest Picture: Amadeus
1994Turned 70
Nelson Mandela elected president of South Africa
Gas: $1.11/galHome: $90,400Min wage: $4.25/hrPresident: Bill Clinton"The Sign" — Ace of BaseBest Picture: Forrest Gump
1998Died at 74
Google founded; Clinton impeachment
Gas: $1.06/galHome: $107,300Min wage: $5.15/hrPresident: Bill Clinton"Too Close" — NextBest Picture: Shakespeare in Love
Key Achievements
- Developed the core mathematical theory for reconstructing internal structures from external X-ray projections, the foundation of CT scanning.
- Awarded the 1979 Nobel Prize in Physiology or Medicine jointly with Godfrey Hounsfield.
- Achieved this Nobel-winning work without holding a doctoral degree in any scientific field.
- Served as a professor of physics at Tufts University for the majority of his academic career.
Did You Know?
He initially pursued his groundbreaking research while working as a nuclear physicist at the University of Cape Town and a hospital.
His seminal papers were published in the 'Journal of Applied Physics,' not a medical journal.
He was an accomplished mountain climber and served in the South African military during World War II.
Cormack became a naturalized citizen of the United States in 1966.
“I saw the problem as one of pure mathematics: how to see inside from the outside.”
