According to Wikipedia’s article on Albert Einstein, he wrote four papers in 1905, three of which were generally considered to be Nobel-worthy. Those three were about the photoelectric effect, Brownian motion, and special relativity. What was the fourth one about?
But the wikipedia article you linked to answers that question:
It would seem Wikipedia got it wrong…it looks like only 3 papers were written.
Google on it and you find things like I linked above all over the place and all seem to be in agreement on this point.
There seem to be four 1905 publications in Annalen der Physik listed in this PDF document.
A couple of recent books, including Einstein’s Miraculous Year, by Roger Penrose and some of John Stachel’s works talk about five papers in 1905.
The canonical number is that he wrote the five that are included in Einstein’s Miraculous Year (which I’ll hereby recommend on the SDMB for the second time this week).
There is a slight ambiguity to do with the doctoral dissertation on molecular dimensions. This was submitted to the University of Zurich on July 20th 1905 and accepted. He then submitted a slightly revised version to Annalen der Physik, who received the manuscript on August 19th. Due to the usual sorts of delays and the production schedule, this paper didn’t actually appear until one of the 1906 issues of the journal. However, the fact that this was submitted, if not actually published, in 1905 means that it’s justifiably traditionally included with the 4 that appeared in that year.
Personally, I’d rate any of the five as having been worthy of a Nobel.
Often overlooked is Einstein’s sixth publication that year — a mouth-watering collection of holiday recipes for the hostess on a tight budget. (Collier’s, special Christmas issue.)
Worthy of a Nobel? You might scoff, but have you tried his Spaetzle Snickerdoodles?
The papers that introduced Special Relativity and the equivalence of matter and energy to the world weren’t Nobel worthy, but the one on Brownian Motion was??
That Nobel commitee is a tough crowd to please.
No, it was the one on the photoelectric effect for which he received the Nobel Prize. Relativity was still a political hot potato, so it was a compromise.
I can’t find the rules on the Nobel Prize, but it seems a person may only receive one Nobel Prize in their lifetime. If this were not the case, and multiple physics prizes could be given in a single year, how many Nobel Prizes would Einstein reasonably be said to have deserved
There is no such rule, of course. Madame Curie won two, one in physics, one in chemistry–but John Bardeen won both of his in physics Etc.
Einstein did not win the prize in 1905, he won it in 1922. 
And there is a lot of work that he did that hadn’t come to fruition by the time he died (Nobel Prizes are not given posthumously–the usual reason given for Rosalind Franklin not receiving one for DNA). For instance, the Bose-Einstein condensate was theorized, but only achieved in the last ten years–and the ones who did achieve it received a Nobel Prize. And there’s the Einstein-Rosen bridge…
No, there have been people (2 or 3, I think) who have received more than one Nobel prize.
But they have been in different categories; for example, one for physics and later the Nobel Peace Prize. I don’t know if this is a rule, or just the way the Nobel prize comittee does it.
(Actually, since prior Nobel prize winners are asked to recommend possible future winners, it would be sort of a conflict of interest if they could recommend themself.)
The fact that a person can win more than one Nobel Prize is clearly evidenced by the fact that one of Linus Pauling’s most notable accomplishments is that he is the only person to have received two unshared Nobel Prizes.
Sorry, I was being lazy—here’s a verifying link.
Not always, see the comment about Bardeen
I though the Brownian Motion paper proved the atomicity of matter, which had long been thought unprovable. Seems like a major accomplishment to me.