"2+2=5 for large values of 2" Huh?

[DSYoungEsq]

Mangetout that makes much more sense. I am sorry that wasn’t clear to me from your initial posting.

[Mangetout]

Thanks. I should probably add at this point that as a ‘man in the street’ myself, the idea that 2 could be considered variable is quite foreign to me as well - being a computer programmer doesn’t help any here. Sorry I got a bit testy.

[DSYoungEsq]

Hehehe, if you think it’s tough for **you]/b] to wrap your mind around, try teaching that idea to 14-year-olds.

[Telemark]

@Princhester

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.

I’ve worked in computers for the past 25 year and I’ve heard scores of people use this joke. Not once (as far as I can tell) has rounding been the point of the joke. Most of the time it was just a silly joke. Sometimes people have used it to make the point that assumptions aren’t always valid. And I worked on math libraries; we dealt with rounding issues all the time.

So, I have a second data point with which to evaluate the Wikipedia data. I agree it means something, I just don’t know what. I contradicts my real world experiece from people I’ve seen using the joke, presumably in the environment that spawned it. Perhaps in the hard sciences its treated differently. Perhaps I’ve hung out with a confused crowd. Perhaps the folks who contribute to Wikipedia don’t have much of a sense of humor. I don’t know and I can’t really evaluate who chose to comment on the Wiki page.

I have hundreds of people I know nothing about, compared to scores that I do know a lot about. For now, I’m still going with the simple joke explanation. I’m open to more data but I don’t find the Wiki page very convincing at this point.

[Colibri]

As long as we are compiling our anecdotal experiences as “data,” in a 30-year career in science I would say I have only encountered this joke in the context of approximation or rounding. I probably encountered it first in relation to statistical analysis, possibly in grad school in the 1970s.

Now it’s possible that hard scientists tend to perceive it as a silly joke, since they don’t think of 2 as a variable. On the other hand, biologists and other scientists who deal with sloppier data may tend to perceive it as saying something a bit deeper about the nature of variability, although in a facetious way.

With relation to the OP, regardless of its origin it is unquestionable that the joke is commonly understood to refer to approximation, even if not all scientists in all fields understand it this way.

[Telemark]

That may very well be the cause of the difference. I’ve never worked in a “real” science like bio, chem, physics, etc, just software. Our work with rounding is on a very different level then yours.

Does anyone have a first reference for the line?

[Chronos]

Thanks. I should probably add at this point that as a ‘man in the street’ myself, the idea that 2 could be considered variable is quite foreign to me as well - being a computer programmer doesn’t help any here. Sorry I got a bit testy.

I take it, then, that you’ve never programmed Fortran? In some old versions, it was actually possible to accidentally re-define numerical constants like 2, through the Fortran style of pass-by-reference. If, for instance, you had a function called “AddOneToX()” (forgive my probably incorrect syntax; I’m not a Fortran programmer either), and the function had a line in it like “x = x + 1”, then if you called “AddOneToX(2)”, then for the duration of the program, 2 would have the value 3.

[yabob]

@Chronos

I take it, then, that you’ve never programmed Fortran? In some old versions, it was actually possible to accidentally re-define numerical constants like 2, through the Fortran style of pass-by-reference. If, for instance, you had a function called “AddOneToX()” (forgive my probably incorrect syntax; I’m not a Fortran programmer either), and the function had a line in it like “x = x + 1”, then if you called “AddOneToX(2)”, then for the duration of the program, 2 would have the value 3.

Don’t remind me of FORTRAN’s call-by-referencedness. When I was a grad assistant, students would sometimes manage to do that. The system they were working on normally placed the literal table in protected memory so that you would get a memory protect error if you tried to modify a literal constant. Every so often, a student would discover the options for running their program which would change the protections, and decide, for some vague reason, that they needed to make their program segment (which contained the literal table) writable. And THEN they would have very mystifying bugs where they changed literal 2 to 357 or something.

ETA:

Of course, implicit declaration was a far GREATER evil, because EVERYBODY managed to run afoul of that one.

[Telemark]

I asked a few people at work, and I was pretty surprised at the answers. First, most folks hadn’t heard of it before. That amazed me; it’s been around as long as I remember and it’s kind of mind boggling that folks in computers hadn’t heard it.

Anyways, about half thought it was about rounding, the other half were convinced it was related to constants not remaining constant. Everyone thought it was funny.

[Snoops27]

2+2=5 first appeared in George Orwell’s 1984. “for extremely large values of 2” is added by quantum physicist, Prof. Lawrence Krauss, to lighten the mood in his talks and lectures. It’s a JOKE, GET IT???:smack:

[Snoops27]

@DSYoungEsq

No, I am not whooshing anyone.

First, you made an assertion that, as I’ve explained, doesn’t make sense. Then someone made an assertion that the whole thing is just a joke with no real meaning, like saying something contradictory just to get a laugh, rather than pointing out a specific thought process about numbers and rounding. I’ve asked that person for a citation that this is the case, that the “metajoke” as that person put it came AFTER the joke itself.

The phrase is a carefully constructed attempt to show an anomoly: the variance in thought between what most people learn in the way of the meaning of cardinal numbers (integers) and the potential actual meaning of cardinal numbers (real numbers that have been rounded to the nearest integer). It uses a patently nonsensical mathematical calculation to demonstrate this anomoly. It’s almost inconceivable that the phrase was developed as nothing more than a nonsensical joke, and then someone else came along later and said, “You know, that actually makes sense if you interpret it this way…” :dubious:

Please watch “The Quantum Man” lecture by Prof. Lawrence Krauss, a quantum physicist, on youtube. He uses the JOKE during the talk and btw, has a T-shirt with the phrase printed on it. IT’S A JOKE!!! GET IT???

[johnpost]

zombie or no

it’s an old joke.

[Leo_Bloom]

Just want to throw in here that “original intention” is a deeply problematic concept, and has received hefty intellectual debate in literature and musicological circles, both as to its normative sense, such as can be reconstructed, and to its revised sense, that such reconstructions are a) impossible to grasp, given the “receding horizon” of an individual author’s --or, indeed, his common–cultural experience; and b) that given this situation, the sense of “original intent” of the creator can be placed in the shadow of the interpreter’s apprehension–the manifesto of the Deconstructionist explosion in the 1980s in literature critical studies.

So, all bets are off.

Way to kill a joke, Leo.

[md2000]

I saw this joke in. The mid 70s.

In typical number theory (about 2nd or 3rd year university courses) we would talk about things like how long an algorithm would take to execute. Consider a simple linear expression versus a squared expression.
A*x can be larger or smaller than x^2 depending on the values of A a constant and x a variable.

But, pick any fixed value for A and " for sufficiently large values of x, the x^2 expression is always larger than Ax."

The expression "for sufficiently large values of… " is pretty common for that sort of math analysis. It says that once the value of x makes this true, it is true for any value of x larger than that.

“2+2=5 for sufficiently large values of 2” is just a nerd joke - like jokes about strange matter or byte/bite jokes (or the more esoteric nibble/nibble corollary). All the earlier posts explain the humour of confusing a variable and a fixed constant.

(For example - crook’s variable constant C, used in Engineering, where y=Cx, y is the desired result and x is the observed result)

[CookingWithGas]

@md2000

The expression "for sufficiently large values of… " is pretty common for that sort of math analysis.

I like this explanation best, albeit a few years late. It’s like the joke with a punch line about an economist who says, “Assume a can opener.”

[Trinopus]

@Leo_Bloom

Just want to throw in here that “original intention” is a deeply problematic concept, and has received hefty intellectual debate in literature and musicological circles, both as to its normative sense . . .

Way to kill a joke, Leo.

Oh, I dunno. I’m laughing!

(Sure, parodying deconstructionist cant is shooting fish in a barrel, but you did it with panache!)

(Say, has anyone ever actually shot fish in a barrel?)

[Senegoid]

@Mangetout

Interesting - the way it was explained to me (I forget where) was subtly different to that - it wasn’t about rounding, so much as about geeky tunnel-vision - to be so focused on the theory of the thing as to overlook the obvious hard, real-world fact that 2 is not a variable.

Exactly this. When I first saw this statement, about 35 years ago (worded as “2 + 2 = 5, for extremely large values of 2”) I had to read it over about 10 times before I “got” the joke.

@RealityChuck

Folks, it’s a joke. It always has been a joke. It’s the type of joke that makes the joke teller the butt because it’s blatantly impossible for the number two to be anything other than the number two.

<snip>

Now, as a metajoke, people are pointing out how by rounding you can get to five, but that came later and is not necessary in order to understand the original joke, which is “large values of 2” is a nonsense phrase.

Exactly.

[Senegoid]

@don_t_ask

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./

Why is somebody using PI in a COBOL program?

[Snoops27]

@Leo_Bloom

Just want to throw in here that “original intention” is a deeply problematic concept, and has received hefty intellectual debate in literature and musicological circles, both as to its normative sense, such as can be reconstructed, and to its revised sense, that such reconstructions are a) impossible to grasp, given the “receding horizon” of an individual author’s --or, indeed, his common–cultural experience; and b) that given this situation, the sense of “original intent” of the creator can be placed in the shadow of the interpreter’s apprehension–the manifesto of the Deconstructionist explosion in the 1980s in literature critical studies.

So, all bets are off.

Way to kill a joke, Leo.

I don’t know why you are making such a great effort to sound intelligent/educated ( I can find that quote too,you know!!). The ORIGINAL 2+2=5 was written by George Orwell in his book “1984”. The world famous quantum physicist, Lawrence Krauss added, as a humerous addendum, “for extremely large values of 2”. BTW, I asked Professor Krauss about it at a book signing in London a couple of years ago. I’m sorry to say that your inept attempt to sound well-read has simply succeeded in making you look rather silly.

[Francis_Vaughan]

I suspect that was the sound of something wooshing overhead there.

Being a compcsi/pure math guy, I always heard it, and interpreted it in the field where two was an integer, and the joke came from the phrase “large values of”. I find it very interesting that there is a version told in the field of statistical analysis (as mentioned by Colibri earlier) where the meaning is both different, and the joke remains funny (although for different reasons.)

Actually I think the first version I heard required “sufficiently large values of”, and didn’t involve 2 and 5, but some other similar form, but it is so long ago I’m totally sure. I’m imagine, like most jokes, it has been retold, and morphed in many ways. Whilst the genesis might be an Orwell quote, it wasn’t funny, so the joke didn’t begin with him, but in quoting him.