Paul Dirac's handwritten notes for his PhD, the first ever on quantum mechanics | Hacker News Reader

Paul Dirac's handwritten notes for his PhD, the first ever on quantum mechanics

academia.edu

147 pointsColinWright50 comments

"...Dirac was absorbed in writing his Ph.D. thesis, a compact presentation of his vision of quantum mechanics. Confident though he was of his understanding of the theory, he knew as he wrote his thesis that it was not the whole story, for he had recently heard than an alternative version of quantum theory had appeared, one that completely different from Heisenberg's. The author of the new version was the Austrian theoretician Erwin Schrodinger, working in Zürich. He was 38 years old, a generation older then than Heisenberg and Dirac, with a formidable reputation in Europe as a brilliant polymath.
Dirac ignored Schrodinger's theory in his PhD thesis "Quantum Mechanics", the first to be submitted anywhere on the subject. The thesis was a great success with his examiners who took the unusual step on 19 June of sending him a short hand written letter congratulating him on the "exceptional distinction" of his work.
....Dirac disliked celebrations and formality, so he was almost certainly not looking forward to the ceremony. He could have taken the degree without attending it but decided to be there in person for the sake of his proud parents, especially this father, who had given him the money that enabled him to begin his Cambridge studies.
...Wearing evening dress with a white bow tie, a small black cap and black silk down with a scarlet-lined hood, he knelt on a velvet cushion, placed his hands together and held them out to be grasped by the Vice Chancellor, who delivered a prayer-like oration. Dirac arose, a doctor.

Like his father, he had no need of holidays – the long vacations were not for relaxing but for hard work. The university was about to hibernate for the summer and would be virtually devoid of social distractions for the few scholars remaining. It was the perfect environment for Dirac to concentrate even more intensively on his work. Heisenberg and Schrodinger had knifed a sack of gemstones, and the race was on to pick out the diamonds.

-- Graham Farmelo, The Strangest Man

Here is a link to the pdf to save anyone from the signup process. Which was painfully long and annoying.

https://dl.dropboxusercontent.com/u/155545/dirac_1926_disser...

I didn't realize that academia mandated a sign up for download of content. IIRC their position was that signup would be optional in order to differentiate themselves from traditional academic publishers who protect access to their content with paywalls/subscriptions. Clearly, either I was mistaken or they have changed their policies.

Looks like your link is so popular that Dropbox has temporarily disabled it!

Yea, dropbox has a 20gb limit on public downloads so the file being ~28mbs means its been downloaded around 700 times.

There's nothing like looking at that Table of Contents to put your own PhD in perspective!

How big was your table of contents?

It's less the size and more the breadth. A lot of people in sciences now feel like the "big discoveries" have been made (at least until the next paradigm shift comes along) and all we can do now is an incremental grind in some highly specific area.

Reading Dirac's table of contents is like reading the chapter headings in my undergrad quantum physics textbook. The thing is though, he's actually responsible for a lot of it!

Indeed, although some of this is the luck of timing. E.g. Richard Feynman would likely have been one of the great names in quantum mechanics ... if it weren't for the fact he was 8 years old right then. Linus Pauling, born 17 years earlier, became the 20th century's most preeminent chemist in part because he was a fricking genius and writer (many of his books are still useful today), but key was that also in 1926 he got a Guggenheim Fellowship to study under some European physicists like Bohr and Schrödinger for a couple of years, and was therefore one of the first to apply quantum mechanics to chemistry, a very fruitful approach.

Wait, Feynman wasn't one of the "great names in quantum mechanics"??

I think the point is that Feynman came later to contribute to Quantum Electrodynamics, the "first theory where full agreement between quantum mechanics and special relativity is achieved."*

* https://en.wikipedia.org/wiki/Quantum_electrodynamics

Feyman was too young for the really fundamental work on quantum mechanics. He won his Nobel prize for his work on quantum electrodynamics. However, he created the path-integral formulation of quantum mechanics, which can be thought of as another way of describing quantum mechanics.

yeah, I was thinking, uh, the path-integral formulation?? Which IIRC is still kind of mathematically ill-defined, but still.

making a fundamental discovery is not necessary to be a 'great mind', I think. As the man himself said, 'what I cannot create, I do not understand'.

It's worth mentioning that the path-integral formulation had a seed in Dirac: http://en.wikipedia.org/wiki/Path_integral_formulation

Yes, echoing the others Feynman was too late for the foundational, completely change your view of the universe stuff.

Gamow's Thirty Years that Shook Physics: The Story of Quantum Theory http://www.amazon.com/Thirty-Years-that-Shook-Physics/dp/048... is the standard non-specialist account of this, it starts with Plank right after the turn of the century and is essentially complete in 3 decades, about when Feynman was in high school and teaching himself serious math.

One of the interesting things in http://businessinnovation.berkeley.edu/WilliamsonSeminar/jon... is the graphs and comments on quantum mechanics - everyone involved got degrees and did their Nobel-worth work astonishingly young. The 'bag of jewels' metaphor really is apt, because it seems you had only to be young and flexible-minded to do groundbreaking work. There will probably never again be a period of such riches in physics (he said in 2013, more than a century after Planck's quanta).

http://rjlipton.wordpress.com/2013/06/25/it-takes-guts-to-do... also comes to mind as Dirac and quantum mechanics related.

In the late 19th century, many physicists thought they had physics pretty well sewn up, with just a few loose ends. Of course it turns out that those loose ends led to quantum mechanics and relativity, completely revolutionizing the field.

Today it seems that physics has most things pretty well figured out, but there are the loose ends of dark matter and dark energy. We don't know exactly what they are, but they seem to make up almost 95% of the content of the universe! So there might still be a chance for another wholesale revolution or two in physics.

'Quantum Mechanics by Paul Dirac'

Other historical theses:

1. 'Gravity by Newton'

2. 'Evolution by Darwin'

3. 'The Earth Orbits the Sun, Not the Other Way Around by Copernicus'

"The Strangest Man: The Hidden Life of Paul Dirac" is a good read if your interested in learning more about Dirac's life.

I asked my Dad about Dirac, he never met him but he once wrote him asking for clarification of something in a book, and got a handwritten letter back. He doesn't actually remember what was in the letter, but he does remember that somebody borrowed the letter and never returned it. Pissed him off, so we're going to try to get it back.

http://ecommons.library.cornell.edu/bitstream/1813/80/34/str...

http://ecommons.library.cornell.edu/bitstream/1813/80/35/str...

http://ecommons.library.cornell.edu/bitstream/1813/80/36/str...

These three lectures by Hans Bethe are really interesting to watch and gives you a historical perspective on the development of Quantum Physics. Given his age, the delivery is a bit slow, but it piques your interest in the subject.

That is the most beautiful handwriting I have ever seen.

Very nice! ------ I'll throw another link into the pile. A 54min lecture on the life of Paul Dirac. https://www.youtube.com/watch?v=YfYon2WdR40 The lecturer is very engaging and this a very approachable talk for those not versed in physics.

Dirac went to FSU? Wha???

Maybe they bought his papers from the estate after he died?

Yes, he went to Florida State University in the dawn of his career. This explains the watermark.

Indeed, he went to Bristol and Cambridge, whence he developed his relativistic quantum theory.

He relocated to Florida towards the end of his life.

*edited the part where I assert OP was wrong.

We are splitting hairs here. What is wrong? That his career dawned in Florida?

I'm sorry, I completely misread what you wrote!

The 'dawn' part is wrong.

http://www.merriam-webster.com/dictionary/dawn

In English, "dawn" only occurs in the morning, so when used metaphorically it always refers to the advent of a thing. The word you're looking for is "twilight", which when used metaphorically means the end or decline of a thing. Thus Nietzsche's Götzen-Dämmerung is translated Twilight of the Idols.

There's also the word "dusk", which is the opposite of "dawn", but it tends not to be used metaphorically.

Some live footage of Dirac at FSU:

http://www.youtube.com/watch?v=fWo010EsiYk

so many threads on hacker news get voted to the top without any comments at all. usually you're supposed to read the article, but in this case i doubt anyone is really capable of understanding it. so in conclusion, aside from this one the article has the appropriate number of comments.

this is all very standard stuff for a physicist. Any first or second year grad student should have an easy time digesting this.

"Pshaw, even the most dimwitted individual should understand this, provided they have a BS in physics, were accepted to grad school, and are in their first or second year."

Nah, this is undergrad physics these days. 3rd or 4th year undergrad physics admittedly :)

Relativistic quantum mechanics typically isn't covered during undergrad. Maybe touched on briefly.

I don't know what university you went to, but it definitely was on my course. Second or third year. The idea that you wouldn't cover relativistic QM in undergrad physics is pretty absurd, and probably indicative of how shallow American undergrad degrees are.

Defensive American undergraduate educated anecdote: my degree was in computer science and I studied this third year. Can't speak for anybody else.

Computational QM is a thing these days :)

Yep, didn't mean to suggest the course is irrelevant to computer scientists. I meant to imply that if they're teaching it to CS students third year, presumably physics students are learning it earlier and/or in more depth.

There are ~2,500 institutions in the U.S granting bachelors degrees, and you're happy to make sweeping generalizations about all of them.

Cambridge Physics Part II (third year of the Natural Sciences tripos) includes relativistic QM as a core 3rd year topic.

The Cambridge Physics course is fairly hard core of course, but I would expect such a course to be part of any serious Physics undergraduate degree in the UK.

I had a quick scan, seems pretty readable, you can skip the maths if you can't follow it and still get a sense of the work from the written material.

I scanned it and I think it's awesome. I'll go back to it later probably.

Having said that I wouldn't recommend anyone to read this. Instead, there's this awesome gem, which I have read multiple times. Don't believe anyone who says it's outdated and you shouldn't read it.

P.A.M. Dirac: The Principles of Quantum Mechanics

http://www.amazon.com/Principles-Quantum-Mechanics-Internati...

I agree with some of his points. My opinions means shit though.

Wow! This must have been a lot of work to write this all down.

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