I won't go into a lot of stuff about quantum mechanics and what it's like and so on...you've heard a lot of wrong things about it anyway!
Which got me wondering: is more said which is wrong about quantum theory than any other theory in physics? Now certainly there are those who will interpret Einstein's relativity (which one they probably won't tell you) as some postmodern "everything is relative" mantra. But (and maybe because I'm locked in a quantum closet all day) it seems to me that even this really bad interpretation of relativity doesn't compare to the amount of total gibberish I've seen about quantum theory.
Since the Standard Model is "The Theory of Almost Everything" it should be the most messed up in giving explanations. But look at some of the dreck done with thermodynamics, and that might be there also. Then look at the physics the creationists use ... but that is so off it probably doesn't count.
I have to vote for relativity.
When I was in physics grad school I mostly was an RA, but I had to have a TA for one quarter. The subject was "modern physics" at more or less the sophomore level. My efforts mostly consisted of helping students do homework in "recitation" sections.
One day this problem came up: "Spaceship A leaves the Earth going at speed 0.75c in one direction. At the same time, spaceship B leaves the earth going at speed 0.75c in the opposite direction. In the rest frame of the Earth, how fast are the two spaceships separating?"
The answer, of course, is 1.5c, which was probably in the back of the book. (Velocities simply add in any single reference frame.) The students argued with me for some time because it was in contradiction to one thing or another that the professor had supposedly told them. I had to gently insist that the professor had not actually said whatever he was being quoted.
This same student / professor (I want to say experimental plasma physicist but I really can't remember) combination never got to mangle QM because the mathematical techniques are too complicated. So I think relativity is probably more abused than QM.
I must vote for Quantum Mechanics.
Random people, with no understanding of physics whatsoever, such as tarot card readers, spiritual gurus, etc. claim that quantum mechanics somehow proves the nonsense they believe in.
I'm not entirely sure that this is the kind of thing that can be settled by a vote, though if it is I woud surely vote for QM.
Relativity does get mangled, particularly by people who don't have a decent grounding in mathematics, but the basic assumptions and consequences are fairly easy to understand. The problem is often that people simply don't accept time dilation.
Quantum mechanics has much the same problem. Unfortunately superposition and entanglement seem to be far harder for people to grasp than time dilation (presumably everybody has at some point seen a movie with a time machine or something similar). The fact that people simply don't understand what these two (or one, depending on your perspective) phenomena are leads to all kinds of dreck. There seems to be an attitude that if you don't understand some phenomena, and you don't understand quantum mechanics, then you can ue QM as an explanation for the first phenomena.
This really isn't helped by all the quotes from famous physicists saying that nobody understands quantum mechanics. At the level on which crackpots operate, we do in fact understand quantum mechanics extremely well.
What if SR were Ptolemaic, i.e., wrong explanation for a nonexistent "perceived" phenomenon: constancy of C vs epicycles, and QM, Tycho-Braic, i.e., accurate observations, but wrong perspective: space-time continuum vs geo centrism? Just wandering what effect it would have on all scientific pundits?
What about the people who confuse QM with relativity, and then say that their hybrid bastardization is really just what Eastern mystics have been saying for thousands of years anyway?
I think the most important difference is that the relativity deniers are quite funny, while the quantum crackpots are mostly just annoying.
... but nothing is as infuriating as a host, who after your talk on quantum information wittily remarks that "the audience is in a superposition of understanding and not understanding" the talk. These people should be shot.
My faith in Gell-Mann's understanding of QM, never mind ability to convey correct physics, was not enhanced by reading his paraphrasing of Bell's theorem in "The quark and the Jaguar", where he seems to say that Bell correlations are just like Bertleman's socks. (The famous socks being introduced by Bell precisely to explain why quantum correlations cannot be understood as of this form).
Possibly Gell-Mann thinks that because if you tell him what measurements were actually performed on an entangled pair of particles he can then find some classical values to assign to the spins of the particles in transit which reproduce the measured correlations that all is well. (Insert appropriate rolling eyes emoticon here...)
Tez: You do realise he won a Nobel prize for work on particle physics, right?
Yes Joe I am well aware who Gell-Mann is :)
I have met many particle physicists who didn't understand Bell's Theorem. In fact I met a different particle physicist who also won a Nobel Prize and didn't understand it! That was 't Hooft, and unfortunately I didn't manage to convince him he hadn't understood it in the 15 minutes I chatted to him.
However Richard Gill, who is at the same institution, did eventualy convince him. He mentions this on page 5 of quant-ph/0110137.
So while I can't tell about Gell-Mann for sure until I've talked to him, I can certainly "prove" that knowing Field Theory well enough to win a Nobel Prize doesn't automatically imply understanding Bell...
Dave Bacon: I think that there are significant cultural differences.
"Culture brings the past into the present and projects it into the future. Culture reinforces precedents and carries forward tradition. Culture provides for stability and continuity, and in that way can be a very good thing. Culture can also resist change and innovation, smothering personal freedom, creativity, experimentation, and progress. In business, company culture can cut both ways. If the external realities are fairly stable, and the company has a strong identity and culture that is in alignment with those realities, then culture contributes to success. However, when external circumstances change dramatically, requiring equally substantial change within the company, a strong culture can often interfere with the company's ability to adapt. Unless the culture is one that values rapid response, creativity and innovation, and readily embraces change, quite often culture gets in the way of a company's ability to change."
"Good writing has to be based on good speech, and good speech is a logical, though complex, development from natural speech. It is a striking feature of our culture that so much creative activity in literature, as in music and painting, should be either explicitly academic or explicitly resistant to education, a culture either of Brahmins or of Dharma bums."
[The Stubborn Structure, Northrop Frye, Metheun, 1970].
"President [Takuo] Tsujimura and his son believe the Japanese way of thinking is slow, stubborn to change, and tends to regard a system of 'sameness' as a good goal."
EPR is like Bertlemanns socks, but really more like Bertlemanns socks and gloves. Colors of socks or gloves is perfectly anticorrelated but if you measure Bertlemann to have a red glove then his socks are in a Bell state. It is like perfect classical correlations if you look at just ONE variable, which is why some classical like models can sometimes do much better than you would think. To see two particle quantum weirdness you need to look at two noncommuting aspects of both particles.
As far as particle physics goes, many wonder why those of us in quantum optics/quantum information "are still trying to prove that QM is right". Before going to grad school I might have agreed with them.
Dave I notice that Joe reminds us that Dr. Gell-Mann was awarded the Nobel Prize. That in itself isn't a slam dunk, considering who some of the other recipients have been, and are about to be :-) The thing that had me sort of smile is when he referred to beauty and chance as the essence of everything. In other words, disorder and order seem to add up to something, where disorder serves as the universal constant (or truth). I always find it interesting when physicists point to simplicity and symmetry as consistent qualities of nature on one hand, then in the same breath claim that its persistence and continuance to be the logical result of an accident(s). So this, compounded with the arguments he made in the Quark & the Jaguar, impels me to concur with Gell-Mann that quantum mechanics is by far the theory most screwed up physicists. Further, I would contend the reason it is so maligned and misrepresented by the populous at large is as a direct consequence.