Everybody presses the wrong quote button now and then.
What do you mean by the “original concept?” We are not talking about the simple assertion that “2+2=5”, as Orwell has it, but the specific phrasing of “large values of 2.” The latter is a geek joke.
No, because 2 does not equal 3 even for very large values of 2. When rounded, 2.51 is not a value of two, but a value of three. This is in contrast to the 2+2 = 5 joke, since 2.49 is a value of two.
Who? 
Anyway, my post doesn’t support your explanation, but contradicts it.
How do you know that?
What does that have to do with anything? It was a joke to begin with.
Thank you, Reality Chuck! That means that there are at least two people in the world who interpret the joke that way. I’m not alone any more.
Ok, well, Colibri has pointed out that my interpretation of the phrase appears to be supported by evidence. Anyone wanting to make a different assertion can start ponying up some evidence to the contrary.
That would be Reality Chuck, Mangetout and Chronos, in specific… along with Lumpy and Sioux Chief. STRAIGHT Dope, remember? 
You will presumably grant, however, that someone at IP address 62.78.166.104 adding the assertion to the wiki page one day back in 2005 isn’t rock solid evidence.
The phrase doesn’t have to have one meaning. In my lifetime around physics and math geeks, I have never used nor heard used this phrase in any context or with any intended meaning regarding the pitfalls of poor approximation hygiene. All of my encounters have been along the “increase Planck’s constant” nonsensical line mentioned above. Large values of two? Why, those words seem to make sense together, yet they don’t at all! Hilarious!
This isn’t to say that no one ever gets bonus use out of the phrase by placing it in an approximation context. But, with all due respect to the awesome power of the SDMB, this thread will never answer the question as to what the original inventor of the joke (if there was a unique inventor) had in mind. But it is certainly a fact that there exist folks who do not make any approximation connection to the joke. I personally find it a lot funnier that way.
(Note that the expression “2+2=5” is a obvious way to break the commonly quoted example of a universal truth “2+2=4”. Orwell uses that expression, but he does not instantiate a joke.)
DSYoung, I don’t think this is really a case that can be cast in terms of right and wrong. Clearly, there are some people who hold one interpretation, and some people who hold a different one. Apparently, there are a lot more people who hold one than the other. But how can an interpretation of a joke be itself “right” or “wrong”? The only criteria I can see are whether it’s funny, and whether it’s what the author of the joke intended. Well, both interpretations are at least somewhat funny, though that’s a matter of taste. And knowing how hard it is to track down the origin of a joke, I doubt we’ll ever know what the author specifically intended. It’s even conceivable (though I won’t speculate on how likely) that the joke was developed independantly by people with different interpretations.
While I can see this rapidly degenerating into a multi-page trainwreck as people assert matters of taste as fact …
Count me into this broad camp.
I’ve always related the joke to the fact that in many, many real world examples in physics expressions like 2x+1 will be simplified to 2x given the caveat that this is equality is “true” for sufficiently large values of x.
If x + x = 2x+1 can be taken as true in those circumstances, then 2+2 = 5 is true for x=2 and sufficiently large values of 2.
Overanalysing the joke, it’s funny because dropping/including such trailing constants as convenient is the sort of tactic that’s so obvious and commonplace that an expert will make this sort of move completely automatically and unthinkingly. The statement therefore superficially parses as sensible and everyday (in this context), yet is nonsensical.
By contrast, to my taste, the rounding interpretation is, alas, both too literal and indirect to be funny at all. It merely renders the statement uninterestingly true in one particular narrow sense. As such, it smacks of an after-the-fact rationalisation of the joke.
[sub]Without detracting from your crack RealityChuck, I’ll pedantically note as an aside that it’s extremely common for theoretical physicists to treat Planck’s constant as a variable, particularly to expand stuff as a series in powers of it by way of an approximation. [/sub]
I came across a similar joke years ago in a business analysis course I did. Talking about documenting your programs the lecturer showed a slide of a programmer’s comment along the lines of:
/WS-030-PI has been established so that it will be easy to maintain the program if the value of pi changes in the next few years./
I was the only person to laugh but he went on to say that it is bad form to make jokes in your documentation. Personally I thought it was a very fine joke, it didn’t effect the utility of the program and people who didn’t think it was funny didn’t really even notice it.
Some people on hearing the story insist that perhaps the original programmer wasn’t having a joke, maybe he was allowing for future increases in the accuracy of pi. Yeah right, he is allowing you to type in a value that has a picture like 9V99999999999999999999999999…99999 (how ever many values someone has most recently calculated).
Reminds me of an approximation which is used in particle physics, which holds when the number of families of quarks is large. Except that that number is actually, to the best of our knowledge, 3. But nobody knows of an exact way to calculate (whatever it is; I can’t remember), nor any better calculation, so folks just go on treating 3 as a “large number”.
I was explaining my understanding of a joke - Which, yes, might well be completely off-base due to my ignorance of mathematics conventions, but even if it were not, how the hell would supporting evidence exist either way? It’s a joke, not a scientific hypothesis. If you wish to take this discussion further, there already exists an ideal place for it.
Not rock solid, but pretty damn solid. A wiki entry that does not get edited into oblivion in two years is showing distinct signs of being backed by a good degree of consensus.
I disagree, it is evidence that no one has changed it, nothing more.
I also think it’s merely a joke with no deeper meaning. Just like people on this site have gone into great depth on the “true” meaning of “Why did the chicken cross the road?” I think you can over analyze any good, short joke. I’ve only ever heard it as a joke, with nothing further implied.
If you want to be precise, it’s not just a joke.
It’s a bad joke.
Guys, let’s go back to how what I said got generated:
So far, what we have is an assertion that the phrase isn’t about rounding, but about the “real-world fact that 2 is not a variable” and my questioning of this reasoning on the basis that the phrase has quite the opposite meaning. Notice I’m not saying anything is “wrong” or “right.”
Now, here we have an assertion of fact. It’s a joke, Chuck says, and the meaning of rounding came later. For this particular assertion, I requested a citation.
So here we have confusion on the part of Mangetout, who isn’t able to understand my assertion that his comment appears to be contradicted by the phrase itself, and refuses to try and explain what he means (always a good way out of a discussion :dubious: ). Still, the only assertion that can be “right” or “wrong” is the one from Chuck about which came first, the chicken or the egg.
Now what followed was a series of posts from several posters, all weighing in on the issue of which came first. You will notice that I have not asserted that any particular person’s use of the phrase, or understanding of its meaning, is incorrect. The only “right” or “wrong” remains which came first. On this very limited issue, the only evidence is provided by Colibri. Everything else is of the “well, I recall using it this way way back when” variety which, as we know, is essentially useless as a data point on the issue being mooted.
Somehow, this gets everyone upset, as if I’m telling them that their understanding of the meaning of, or use of, the phrase is WRONG. Not what I have said at all. And I’ll be the first to admit that the Wikipedia citation isn’t rock solid. Pasta has it right that we probably cannot determine the actual origin and meaning at inception.
All of which means that what Chuck asserted about order cannot be stated as fact, *which was the whole point of my simple posting: *
I hope that is sufficient to answer those of you who think I’m asserting that the fact that in 1987 you didn’t think of the phrase as meaning anything about estimation was “wrong.” I’m not saying that, I never said that, and I never will say that. 
I find this a bit disingenuous - as I said, I was explaining my second-hand understanding of a joke, not describing the structure of the atom. You slapped me down. Where was I supposed to go but away?
On the right-wrong thing, demanding evidence to support assertions is tantamount to declaring something wrong - the distinction is trifling at best. You may not have explicitly stated who you think is right and who you think is wrong using exactly those words, but it’s abundantly obvious you are (or were) treating it that way.
Anyway, a more interesting question, IMO, and which others have touched upon, is why is your explanation of the joke funny at all?
Consider the joke:
Q: Why is an elephant big, gray, and wrinkly?
A: Because if it was small, white, and round, it would be an aspirin.
This joke is in the same vein; stupid, cute, and funny. It doesn’t require an explanation, nor would I expect anyone to attempt to explain why it was funny or what the deeper meaning was. Any deeper meaning ascribed to this joke would be useless and detract from the humor, IMO.
Just like with the chicken crossing the road, this hasn’t stopped people from attempting to find greater meaning in those few words. I think finding citations for the origins of most jokes is futile, they are notoriously difficult to track down. So, we’re left with a joke, and some attempts to ascribe deeper meaning to it. I think the joke stands by itself.
This is an untrue assumption. All such a request is doing is making someone who is asserting something back it up. Personally, I have no idea which meaning came first, nor do I have any particularly preconceived notions. I can make my own guess, but that’s relatively unimportant. But Chuck’s ASSERTION needed a citation, else it’s just an assertion of little value in General Questions on the Straight Dope.
As for our initial byplay, you might have explained how you reconciled what you had been told with the issue I brought up. 
Obviously, there is no factual answer to this. (Maybe it’s a Cafe Society thread?)
But, for what it’s worth, I do not hold to the ‘it’s about rounding’ interpretation.
As bonzer points out, it’s common to use the phrase ‘for sufficiently large values of x’ in math/physics. The phrase also has worked its way into engineering and similar disciplines. Sometimes, even where it’s faintly ridiculous (“This is fireproof, for sufficiently low temperatures”). This joke is just making the use of the concept/phrase as ridiculous as possible.
OK, last try then.
If I reword “real-world fact that 2 is not a variable” to “overwhelmingly common perception of the man-in-the-street that 2 is not a variable”, does that help? The guy in the street (the average consumer of jokes) does not typically regard 2 as variable at all.
In this case, the humour derives from the apparent absurdity of (what looks like) a hastily-appended qualifier “for sufficiently large values of 2”, when it seems obvious that the equation itself contains a glaring error - which if corrected would do away with the necessity of (what appears to be) a qualifier.
So the appeal of the joke (when understood thusly) is broadly along the lines of math geeks are smart enough to see the requirement for a qualifier, but simultaneously dumb enough to fail to notice an obvious error that would be obvious to a small, stupid child - i.e. they are highly educated, but have no common sense
Over a hundred people have taken the time to edit that page. Goodness knows how many people have viewed it. You’d have to assume thousands. But no one has thought the relevant part of the page wrong enough to edit it in two years even though they could have, at the touch of key, and you don’t think that is any evidence of consensus? You are burying your head.