Genealogy - Familienforschung - Généalogie

Descendants of Paul Dirac's grandfather Louis-François Dirac ( 1810-1882)

Paul Dirac's ancestors up to his great-great-great-grandparents

Paul Dirac's parents, siblings and children

Paul Adrien Maurice Dirac - 1902 - 1984

Paul Dirac received the Nobel Prize in Physics in 1933 at the age of 31.


P.A.M. Dirac
as a young man



Paul Dirac in his 80's


October 1927 at the Solvay Physics Conference in Bruxelles -
group picture with Albert Einstein, Paul Dirac and Marie Curie

Oct 2013: Zachary S. from Alaska pointed out a factual error in this newspaper article of 1927.
Erwin Schrödinger is not the no. 5 on the above picture, but the man on this person's left (above Einstein). Thanks, Zachary.


1907 - Paul's parents and siblings:
Florence Dirac née Holten, Betty, Felix, Paul
and Charles Dirac






ca. 1945 - Paul's wife and children:
Paul, Monica, Margit, Gabriel, Mary and Judith


Paul and his wife Margit née Wigner

August 1, 1991 - Paul Dirac was honored with a 
commemorative stone placed in a little garden with
his name in Saint-Maurice, the town of origin of his 
forefathers in Valais, Switzerland.



November 13, 1995 - day of the inauguration of a
commemorative plaque for Paul Dirac,
close to the one for Isaac Newton,
in Westminster Abbey in London


Graham Farmelo's biography about
Paul Dirac

“The Strangest Man”

appeared in January 2009 and was/is a big success. It was translated into several languages.


Paul Dirac Anecdotes

Suitably Efficient?
English physicist and Cambridge University professor Paul Dirac was an avid mountain climber and occasionally ascended such well-known peaks as Mount Elbruz in the Caucasus. In preparation for such excursions, Dirac would often climb trees in the hills just outside Cambridge - wearing the same black suit in which he was invariably seen around the university campus.

Logic and precision
Dirac was so unusual in the logic and precision of his interaction with the world, both in and out of physics, that legions of "Dirac stories" have become attached to him and have acquired a life of their own. Often these stories revolve around Dirac saying exactly what he meant and no more. Once when someone, making polite conversation at dinner, commented that it was windy, Dirac left the table and went to the door, looked out, returned to the table and replied that indeed it was windy. It has been said in jest that his spoken vocabulary consisted of "Yes", "No", and "I don't know".

Dirac on Dostoevski
Once Peter Kapitza, the Russian physicist, gave Dirac an English translation of Dostoevski's Crime and Punishment.
"Well, how do you like it?" asked Kapitza when Dirac returned the book.
"It is nice," said Dirac, "but in one of the chapters the author made a mistake. He describes the Sun rising twice on the same day." This was his one and only comment on Dostoevski's novel.

Dirac on ghost
At another time, Dirac was at a meeting in a castle, when another guest remarked that a certain room was haunted: at midnight, a ghost is said to appeared. In his only reported utterance on matters paranormal, Dirac asked: "Is that midnight Greenwich time, or daylight saving time?"

Odd number of places
Like many scientists, Dirac was known to sleep during (other people's) lectures, and then wake and suddenly make a penetrating remark. Once, in Copenhagen, Klein and Nishina reported their derivation of the famous Klein-Nishina formula describing collisions between electrons and gamma quanta. Somebody in the audience remarked that in the formula as written on the blackboard the second term had negative sign, whereas in the manuscript the sign was positive. "Oh," said Nishina, "in the manuscript the signs are certainly correct, but here on the blackboard I must have made a sign mistake in some places."
Dirac opened one eye and said: "In odd number of places!"

Dirac's writing was famous for its clarity and simplicity. When Niels Bohr was writing a scientific paper - with many hesitations and redraftings, as was his custom, Bohr stopped: "I do not know how to finish this sentence." Dirac replied: "I was taught at school that you should never start a sentence without knowing the end of it."

It's not a question
At the quesiton period after a Dirac lecture at the University of Toronto, somebody in the audience remarked: "Professor Dirac, I do not understand how you derived the formula on the top left side of the blackboard."
"This is not a question," snapped Dirac, "it is a statement. Next question, please."

When Paul Dirac made a rare error in an equation on the blackboard during a lecture one day, a couragous student raised his hand: "Professor Dirac," he declared, "I do not understand equation 2."
When Dirac continued writing, the student, assuming that he had not been heard, raised his hand again and repeated his remark. Again Dirac merely continued writing...
"Professor Dirac," another student finally interjected, "that man is asking a question." "Oh?" Dirac replied. "I thought he was making a statement."

Optimal distance to look at a woman
Being a great theoretical physicist, Dirac liked to theorize about all the problems of daily life, rather than to find solutions by direct experiment. Once, at a party in Copenhagen, he proposed a theory according to which there must be a certain distance at which a woman's face looks its best. He argued that at d = infinite one cannot see anything anyway, while at d = 0 the oval of the face is deformed becaue of the small aperture of the human eye, and many other imperfections (such as small wrinkles) become exaggerated. Thus there is a certain optimum distance at which the face looks its best.
"Tell me, Paul," [Gamow, a Russian physicist] asked, "how close have you seen a woman's face?"
"Oh,"replied Dirac, holding his palms about two feet apart, "about that close."

Dirac discovers purling
Another time, Dirac was watching Anya Kapitza knitting while he was talking physics with Peter Kapitza. A couple of hours after he left, Dirac rushed back, very excited. "You know, Anya," he said, "watching the way you were making this sweater I got interested in the topological aspect of the problem. I found that there is another way of doing it and that there are only two possible ways. One is the one you were using; another is like that. . . . " And he demonstrated the other way, using his long fingers. His newly discovered "other way," Anya informed him, is well known to women and is none other than "purling."

Wigner's sister
Dirac married "Wigner's sister", so known among the physicists because she was the sister of the noted Hungarian theoretical physicist Eugene Wigner. When one of Dirac's old friends, who had not yet heard of the marriage, dropped into his home he found with Dirac an attractive woman who served tea and then sat down comfortably on a sofa. "How do you do!" said the friend, wondering who the woman might be. "Oh!" exclaimed Dirac, "I am sorry. I forgot to introduce you. This is...this is Wigner's sister."
(Later when Gamow questioned Mrs. Dirac on this story, she said that what Dirac actually said was: 'This is Wigner's sister, who is now my wife.')

Dirac on poetry
Oppenheimer was working at Göttingen and the great mathematical physicist, Dirac, came to him one day and said: "Oppenheimer, they tell me you are writing poetry. I do not see how a man can work on the frontiers of physics and write a poetry at the same time. They are in opposition. In science you want to say something that nobody knew before, in words which everyone can understand. In poetry you are bound to say...something that everybody knows already in words that nobody can understand.

God used beautiful mathematics in creating the world.

This result is too beautiful to be false; it is more important to have beauty in one's equations than to have them fit experiment.

"Paul Dirac - My Father" - lecture of Paul Dirac's daughter Monica at the
Dirac Centennial Celebration in Cambridge, Sept. 2002 :

Paul Dirac on-line biographies:


Interesting articles about Paul Dirac: by Antonino Zichichi, University of Bologna by Sir Michael Berry, University of Bristol

Physics + Dirac = Poetry by Graham Farmelo


Dirac Genealogy (entry page)
Famile Tree of Pierre-Louis Dirac (1748-1799) and his wife Andréanne Favre
Family Tree of François Dirac (1782-1847) and his wife Catherine Pignat (1785-1851)
Family Tree of Louis-François Dirac ( 1810-1882) including Paul Dirac
Family Tree of François Dirac ( 1817-1899) including the American branch of the family

Paul Dirac, prix Nobel de Physique en 1933
Descendants of Paul Dirac's grandfather Louis-François Dirac ( 1810-1882)
Paul Dirac's ancestors up to his great-great-great-grandparents

Paul Dirac's parents, siblings and children

Le Village Dirac près d'Angoulême (Charente) et de Bordeaux
Philippe Dirac
- document de 1745
Les armoiries de Dirac (coat of arms)


Copyright ©  by Gisela Dirac