Talk:Paul Dirac

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Peer review This article was externally reviewed (December 14, 2005) by Nature. It was found to have 9 errors.

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[edit] What are they anyway?

Nature found 9 errors. You think they could tell us what they are so we can fix them? --24.63.36.180 18:14, 17 December 2005 (UTC)


[edit] External links

The external link page seems to have moved OK. I searched around a little and fixed it.

[edit] Dirac codec

The BBC has developed a video compression codec named after Dirac. http://www.theregister.co.uk/2004/05/10/bbc_develops_codec/ mparaz

[edit] Wigner

I got this from the wiginer article, "In Princeton in 1934 Wigner introduced his sister Manci to the physicist Paul Dirac. They married, and the ties between Wigner and Dirac deepened. Wigner also spent time with Einstein, who had come to Princeton to join the Institute For Advanced Study." However, in this article it claims it is Wiginer's daughter and a different name. Which is correct?

[edit] Pronunciation

How does one pronounce the name "Dirac"? --84.163.89.120 12:05, 13 July 2005 (UTC)

I can't vouch for the correct Swiss pronunciation, but physicists say "Dee-RAK." -- Eb.hoop 06:54, 14 July 2005 (UTC)

[edit] Errors ID'd by Nature, to correct

The results of what exactly Nature suggested should be corrected is out... italicize each bullet point once you make the correction. -- user:zanimum

  • Dirac never worked as an engineer for a living (all he did was a few weeks’ research one summer, directly after his engineering degree).
  • His PhD thesis did not mention Schrodinger’s quantum theory, so the characterization of Dirac’s early QM is not correct.
  • Dirac first became interested in general relativity as a student in Bristol, not at Cambridge.
  • His role in the discovery of field theory is not mentioned.
  • Nor is his extremely important work in the least-action formulation of QM, now very important in modern field theory.
  • I was surprised to see nothing at all about Dirac’s large number hypothesis (1937)
  • Dirac did speak publicy about his early family life in his interview to the Archives of the History of Quantum Physics.
  • He did not ‘derive’ the Dirac equation – he guessed it.
  • He was not a committed atheist in later life. I’d describe him as agnostic.


I've gone ahead and fixed the errors identified. Someone else might want to add more about Dirac's role in the development of quantum field theory. -- Eb.hoop 21:31, 22 December 2005 (UTC)


It would be nice if Nature cited some verifiable sources for its factual statements and critiques:

  • While it is nice to know that the unnamed Nature reviewer says, "I’d describe him as agnostic," I would much rather hear Dirac's own religeous views, to the extent that he stated them. Just my hunch: the reviewer is not, or at least prefers not to characterize him- or herself as, an athiest.
  • Also, the criticism that Dirac "guessed" rather than "derived" his namesake equation is less than a quibble. Yes, I have read that he said that. However, unless one is attempting to describe Dirac's own perception of his internal mental process, the public is in no way misled by the statement that he "derived" it. Indeed "derived" may be the more accurate, objective description, given the constant subconscious mental processing that goes on in the minds mathematicians and other highly creative indivicuals.

I did not write either of these items into the Dirac article, so this is not self-justification. Finell (Talk) 22:39, 22 December 2005 (UTC)

I don't see the least-action stuff? William M. Connolley 21:18, 23 March 2006 (UTC)

Oops, as Aloan points out, its there under "path integral" William M. Connolley 17:56, 24 March 2006 (UTC)

[edit] Discovered ?

Has wikipedia standarized the term for discovering/developing mathematical objects ?. I think not all mathematicans agree that things are discovered, but rather think they are developed.

The question as to whether mathematics has any objective reality or whether it is just a construct of the human mind is an interesting philosohpical one. My POV is that, it depends on the maths: For example, if we imagine an alien race on the other side of the galaxy, they would have to know that the area of a circle = πr2 if they were to make any progress with their crop circles. I'm sure we could recognise that part of their mathematics, if we saw it. That strongly implies that A = πr2 exists out there and that intellects discover it.
However, I'm not so sure they would necessarily have a Dirac equation. They might have something similar that allowed them to model anti-particles but they wouldn't have anything familiar enough to our Dirac equation that we could immediately recognise it.
As an analogy, consider how it would work with technological objects: the aliens might have levers and gears but they probably wouldn't have a 4-cylinder, overhead-cam, 12-valve internal combustion engine. If you go along with that, then perhaps you'd have to say that Dirac invented his eponymous equation.--Oscar Bravo 13:50, 29 May 2006 (UTC)
Ho there, we don't mention that he taught at the University of Miami from 1969 to 1971 (this is a fact). It says that he taught at Cambridge until 1969 and then mentions that he spent the last 10 years of his life (1974-1984, I would presume) at FSU. That's a 5-year gap. Just to say. —Preceding unsigned comment added by Gr33n0r4cl3 (talk • contribs) 23:16, August 28, 2007 (UTC)

[edit] Views

Removed: Dirac believed privately that God was a great mathematician. This underlied his belief that correct formulations of fundamental physical laws would be mathematically beautiful and simple.

A quick check on several physics biography websites revealed nothing like this about his "private" thoughts. If Xanaguy would like to produce an authoritative reference to the assertion, we can put it back in.--Oscar Bravo 13:50, 29 May 2006 (UTC)

[edit] Commemorative garden in St. Maurice

After visiting St. Maurice on a ski-trip in April 2006, I thought it worthwhile to add a sentence mentioning the commemorative garden there. My intial addition was:

A commemorative garden, in his honour, has been established opposite the railway station in Saint-Maurice, the town of birth of his father.

I was a bit surprised, however, by a line on the plaque which described Dirac as, "un originaire de Saint-Maurice". With my limited grasp of French, I took this to mean they were claiming he was born there, so I (unwisely!) added this line to the article:

Despite being born in Bristol, England of an English mother, the plaque in the garden rather cheekily describes him as originating in Saint-Maurice.

Of course, this started a chain of edits as various people pointed out that an originaire doesn't necessarily need to have been born in a certain place, and that parental lineage is sufficient. This is all very interesting but rather irrelevant to M. Dirac. So I removed the whole thing. If anyone is interested, apparently,

Under Swiss law, every child born to a father who is a Swiss national also has Swiss citizenship, in the case of Diracs, they are citizens of Saint-Maurice in Canton Valais. Since Paul Dirac's father, Charles, only renounced his Swiss citizenship in 1919, Paul also had Swiss citizenship until 1919, when he was 17.

--Oscar Bravo 07:43, 14 September 2006 (UTC)

[edit] but/and

I reverted Dirac became unsatisfied ... but his work on the subject moved increasingly out of the mainstream. to Dirac became unsatisfied ... and his work... for semantic reasons. The two clauses are in a causal relationship - because he became dissatisfied, his work moved out of the mainstream. So they should be connected with and (even and so!). Using but to connect the two implies that the second clause is in dissonance with the first, but it isn't... --Oscar Bravo 13:51, 20 September 2006 (UTC)

[edit] Atheist Citation?

I see this question was brought up once already, but are there any citations indicating Dirac was an atheist. I was actively looking for any information on his religious views, but I could not find much. The item that came up the most was this quote:

“God used beautiful mathematics in creating the world" [1]

Unless someone can provide good evidence for him being an atheist I think it should be removed. --Scott 00:33, 9 November 2006 (UTC)

Using Google I did mange to find this:

Brian, Denis (Editor). The Voice of Genius. Cambridge, Massachusetts: Perseus Publishing, 1995.

PAUL DIRAC (Nobel, physics, 1933) (Interview with his wife.)

What was your husband’s attitude toward religion?
He was a Christian. He went to church on Sundays.
You mean he believed in Jesus Christ?
Perhaps sometimes, and sometimes not. You know, most people are like that.
Most people I contacted are atheists.
My husband wasn’t an atheist
Did he feel there was an intelligent creator?
Yes, yes.

(P. 69)[2]

If anyone has the above mentioned book out there to confirm this, it should be case closed. --Scott 23:58, 26 November 2006 (UTC)

I disagree. This website [3] is bias towards believers. Many informations in the website are FALSE. For example, Einstein did not believed in a personal god. But in the website [4] we are told that Einstein had absolute certainty in God's existence, deep reverence for His creative powers, and a total acceptance of His sovereignty!!

The interview was with Dirac's wife. Paul Dirac has never said that he believed in a personal God. As far as I know, from what I have read, Dirac was an atheist. If you guys have other proof, please show me. User: Devraj

Your objection is confused. It is possible, and quite common, to not believe in a personal God, yet not be an atheist. Examples include deists, pantheists, and panentheists. Since we don't really know which of these Dirac was, I'm just changing it to the indisputable "did not believe in a personal God", rather than trying to pin an unverifiable label on him. Djcastel 13:22, 27 April 2007 (UTC)
Djcastel, you are wrong. Deists do believe in a personal God. And, pantheists are just politically correct atheists. User:devraj5000
Some self-identified deists emphatically do not believe in a personal God. See for example, this link.[5] And the judgment that pantheists are really atheists is POV. It would be hard to peg Spinoza as an atheist. Djcastel 19:40, 6 May 2007 (UTC)

I just noticed this Talk and can perhaps shed some light. In a recently discovered 1934 letter from Dirac to Isobel Whitehead, mother of J. H. C., he writes, "I do not think my decision [whether to marry Margit] would be influenced by my believing in God, so I do not know why you are bringing up this point so forcibly. I do not know Lady Hoskins at all well. I am mainly guided in my philosophical beliefs by Niels Bohr, with whom I always feel in complete agreement." The letter is now in the library of St John's College, Cambridge. Dirac's first sentence, with its 'would', suggests that he's discussing a hypothetical rather than real belief in God. I don't know for sure if Bohr was an atheist, but if he was, and Dirac agreed completely with him, that would suggest that Dirac was an atheist too. Sosayso 15:42, 27 April 2007 (UTC)

This is all well and good, but it is not our role to do original research to decide this question. Djcastel 19:40, 6 May 2007 (UTC)
Thanks for alerting me to this. I expect a reputable source will appear in due course that offers new arguments based on the 1934 Dirac letter and other material. Sosayso 20:44, 12 May 2007 (UTC)

Reputable sources for Dirac's atheism have been in List of atheists for quite some time. See the following:

Werner Heisenberg recollects a friendly conversation among young participants at the 1927 Solvay Conference about Einstein's and Planck's views on religion. Wolfgang Pauli, Heisenberg and Dirac took part in it. Among other things, Dirac said: "I cannot understand why we idle discussing religion. If we are honest — and as scientists honesty is our precise duty — we cannot help but admit that any religion is a pack of false statements, deprived of any real foundation. The very idea of God is a product of human imagination.[...] I do not recognize any religious myth, at least because they contradict one another.[...]" Pauli jokingly said: "Well, I'd say that also our friend Dirac has got a religion and the first commandment of this religion is: God does not exist and Paul Dirac is his prophet." Physics and Beyond: Encounters and Conversations Harper & Row New York isbn=0061316229

"... I [Pauling] am not, however, militant in my atheism. The great English theoretical physicist Paul Dirac is a militant atheist. I suppose he is interested in arguing about the existence of God. I am not. It was once quipped that there is no God and Dirac is his prophet." Linus Pauling & Daisaku Ikeda A Lifeling Quest for Peace: A Dialogue 1992 Jones & Bartlett isbn = 0867202777 pages = page 22

Nick Graves 16:31, 15 October 2007 (UTC)

Paul Dirac was indeed an atheist when he was young, but later in life he became a Christian and attended church on Sundays. He also became a member of the Pontifical Academy of Sciences. "The Voice of Genius" has an interview with his wife, who confirms this claim. This book is not a biased account, as it is full of interviews with renowned scientists who are/were atheists. The interview with Mrs. Paul Dirac can be read here: http://books.google.ca/books?id=x1BYMA-8oq8C&pg=RA1-PA72&lpg=RA1-PA72&dq=the+voice+of+genius+paul+dirac&source=web&ots=pwm9Umt_Na&sig=QUgpkPVNEPxUoioMKG703qm6iGA&hl=en#PRA1-PA69,M1 —Preceding unsigned comment added by 74.13.73.231 (talk) 04:26, 26 April 2008 (UTC)

Yes, Mrs Dirac is quoted as saying that, the quote is above. She also replied to a question about George Gamow's comment re Dirac in his book Thirty Years that Shook Physics with "I don't read science fiction." The interview is interesting indeed. Vsmith (talk) 14:06, 26 April 2008 (UTC)

[edit] How is this section relevant to Paul Dirac

Eugene Wigner, Dirac's brother-in-law, once described Richard Feynman as "a second Dirac, only this time human".[1].

This is nothing to do with Dirac himself so I suggest that this should be deleted.


--pizza1512 Talk Autograph 15:16, 14 July 2007 (UTC)

[edit] Statue of Dirac at FSU

It seems like it might be worth mentioning that outside of the science library dedicated to Dirac at FSU there is a full-sized statue of him sitting on a bench? I don't know how to write it well, but... it's there. Also, I can get a good picture of said statue (and/or the library) if anything thinks it'd be useful. Luthwyhn 05:22, 24 October 2007 (UTC)

[edit] When did the bra-ket notation came ?

In Dirac : a scientific biography, p. 177, we are told it is in 1939 [6], while the article suggests 1930 and in the fr wiki, 1925 is suggested... The biography seems to trace it back to an article, but I only have the google online version with limited content, so if someone could check and eventually correct, it would be great! --67.71.75.220 (talk) 06:17, 19 January 2008 (UTC)

OK, the biographer was right, and this 1939 article has an explicit title : A New Notation for Quantum Mechanics. The reason the article is wrong is probably given in François Gieres, Rep. Prog. Phys. 63:1893 (2000) arXiv:
“ ...the bra and ket notation that Dirac developed from 1939 on, and that he introduced in the third edition of his celebrated textbook on the principles of quantum mechanics ”
So it is probable that the person writing the article did not have the original edition of Dirac's textbook, and believed it was written using bra-ket notation ever since the first edition. I'm going to fix this, now. --67.71.75.220 (talk) 04:17, 22 January 2008 (UTC)