42

It is as we know (quotes from Wikipedia):

• the "third primary pseudoperfect number"
• the "only known value that is the number of sets of four distinct positive integers a, b, c, d, each less than the value itself, such that ab − cd, ac − bd, and ad − bc are each multiples of the value".
• the "smallest positive integer which is conjectured to be representable but which has yet to be represented as the sum of three cubes a³ + b³ + c³, where a, b, and c are integers"
• the atomic number of Molybdenium
• the Kepler number of "a red dwarf in the constellation Cygnus around which orbits the three smallest exoplanets found to date"

and of course

• the "Answer to the Ultimate Question of Life, the Universe, and Everything".

And the rest is history, 42 has become a meme, and you'll find references to it everywhere, not only in popular culture, but also in non-fiction (admittedly with a somewhat geeky bias). What I find funny is that for many (non-geek) people, those references will go by undetected.

For instance, in "Ivor Horton's Beginning Visual C++ 2013 (Wrox)" we find on p. 55:

"It is very useful to define constants as const variables, particularly when you use the same constant several times in a program. For one thing, it is much better than sprinkling literals throughout your program that may not have blindingly obvious meanings; the value 42 could be referring to the meaning of life, the universe, and everything, but if you use a const variable with the name myAge that has a value of 42, it becomes obvious that you are not."

I have decided to dedicate part of my retirement to collect references like that. Deliberate ones as well as accidental (trivial) ones.

I can and I will of course search the net, but your contribution will be greatly appreciated, and may also perhaps be of interest to other watchers. I would appreciate if you would cite them as accurately as possible, and provide exact references, so I can find them. But don't sweat. Anything will do.

pibbur who was 42 22 years ago.

PS. Another one:
In the "Latex Document preparation system User's guide and Reference manual" by Leslie Lamport, we find on p 68:

"The \pageref command is similar to the \ref command except it produces the page number of the place in the text where the corresponding \label command appears".
Example: "See page ~\pageref {'meaning') for more details", which refers to the following content allegedly on p. 42: "The \label{'meaning'} meaning of life, the universe, and"
DS.

That looks like an excellent thing to spent time on

And there was given me a reed like unto a rod: and the angel stood, saying, Rise, and measure the temple of God, and the altar, and them that worship therein.

But the court which is without the temple leave out, and measure it not; for it is given unto the Gentiles: and the holy city shall they tread under foot forty and two months.

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Revelation 11:1

6*6+6=7*7-7=42

When you put 42 backwards its 24 which is the number of hours in the day. Put them together and its a palindrome, 4224, meaning the same forward as backwards.

42 is not a recipriversexclusion.

What a great idea and I have also seen 42 referenced in some very odd places. If I find any will let you know .. now that I know someone is looking.

There's also Alice in Wonderland, where the King specifies a rule 42 that forces "All persons more than a mile high to leave the court." Alices suggests he invented the rule on the fly. I personally think the rule is legit, but was originally intended to do away with stoners.

Also, subcommitee 42 of the International Organization for Standardization and the International Electrotechnical Commission (ISO/IEC JTC 1/SC 42) deals with "Standardization in the area of Artificial Intelligence".
https://www.iso.org/committee/6794475.html

Surely not a coincidence?

Found a reference in the last book I bought on Kindle: "Ordinary Differential Equations: An Introduction to the Fundamentals" by Kenneth B Howell:

In the exercises on p5 we are asked "What is the order of each of the following equations?" One of the examples is this one:

d^42y/dx^42=(d^3y/dx^3)^2

The answer (the order) is of course 42. This particular example cannot be a coincidence.

pibbur who claims that very geeky stuff, sometimes requiring specific knowledge, is unavoidable in a thread like this one.

PS. Solving the equation is left to the reader as an excercise. DS.

How to solve that equation - A step by step guide from a practical perspective.
1. Write it on a slip of paper
2. Drop the slip into a bowl of sulfuric acid.

(Note: this joke is marginally more funny in German)

Back on topic: There's a few games with "42" in the title. Squadron 42 (unreleased). Tokyo 42. Room 42. Sad City 42. Attempt[42]. I'd probably rate none of them as the "Answer to the Ultimate Question of Life, the Universe, and Everything"

Also; xkcd = 24 + 11 + 3 + 4 = 42.

Cacheperl said:

How to solve that equation - A step by step guide from a practical perspective.
1. Write it on a slip of paper
2. Drop the slip into a bowl of sulfuric acid.

(Note: this joke is marginally more funny in German)
....

Click to expand...

The German version, please.

pibbur who can read German.

There's not too much difference in the actual joke. The only difference would be that you need some handwaving for the underlying pun to work: "solve" vs. "dissolve". In German you get away with "lösen" for both case: "Lösen von Gleichungen" vs. "Lösen von etwas in einer Säure".

Edit: Or does "solve" also work in a chemical context in English? I actually do not know.

tl;dr; Something pibbur finds interesting, but possibly nobody else.

Found a new 42 reference today. I'm going to implement a Turing machine, and was consulting the net, as it's been some time since I've worked with that concept. It's not important what a Turing machine is, the focus here is the 42 reference.

On Wikipedia, I found the following:

"[TI]he Turing machine mathematically models a machine … Operation is fully determined by a finite set of elementary instructions such as "in state 42, if the symbol seen is 0, write a 1; if the symbol seen is 1, change into state 17[/I]"".

No reference to the question. Is it a real 42 reference? Well, since it is a geeky topic on a to some degree geekiness biased site, I would say the answer is yes.

pibbur who has one question: "In what state, if the symbol seen is 0, will the machine write a 1; and if the symbol seen is 1, change into state 17?" (Disregarding the fact that there might be more than one state that satisfies the question.)

PS. For those who don't but want to know: In short a Turing machine is an abstract model of a computer. It's useful for among other things studyng what computers can and can not do and how complex a task is. It's very important in computer science. DS.

PPS. I have implemented a Turing machine before, when I attended a computer science course. I did it using the Quattro spreadsheet - yes, it's that long ago. Now I'll do it in C#, as part of my "ultimate geek programming project". DS.

PPPS: A joke is in order: Two scientists at a blackboard, filled with formulas, one of them says: "The beauty of it, is that it's of purely theoretical interest. It's got no practical uses whatsoever." Yes, I find it funny. DS

Not really regarding the number 42, except insofar as it might limit our ability to compute the answer to life, the universe, and everything, but there was an interesting debate around some books by Roger Penrose - his theory that the brain is not a Turing machine (and therefore can't be modeled by computation), and that consciousness arises from quantum processes not yet understood. Many refuted his arguments, trying to show that he had misunderstood the limitations of Godel's theorems. I think the consensus has come out against him, but some very interesting conversations around it. I like his books.

I have one book by him: "The Road to Reality, a Complete Guide to the Laws of the Universe". What distinguishes this book from other poplular science book ios that mr Penrose does not skip the mathematics. In fact, a big part of the book is dedicated to give the reader the necessary math background to understand the physics.

pibbur who. nedless to say (so why does he say it?), really like this book.

pibbur who said:

so why does he say it?

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Dry facts are ... dry. Needless remarks, words and gestures are the juice in pleasant conversations.

Sadly 42 is not odd.

42 was the last remaining number below 100 which could not be expressed as the sum of three cubes - UNTIL NOW:

HiddenX said:

42 was the last remaining number below 100 which could not be expressed as the sum of three cubes - UNTIL NOW:

Click to expand...

Verified in Mathematica:
In[1]= a = -80538738812075974^3
Out[1]= -522413599036979150280966144853653247149764362110424

In[2]= b = 80435758145817515^3
Out[2]= 520412211582497361738652718463552780369306583065875

In[3]= c = 12602123297335631^3
Out[3]= 2001387454481788542313426390100466780457779044591

In[4]= a+b+c
Out[4]= 42

pibbur who observes that the "Wolfram Language can handle numbers of essentially unlimited length" (https://reference.wolfram.com/language/guide/NumberDigits.html), for practical purposes limited by available RAM, and he has 42… eh … 32 Gb (don't tell the joxer).

PS. For some reason there is a space before the last digit of the first two numbers. Not sure why, I didn't enter said space. DS.

The interesting thing of the number 42 is, that it creates a thing of itself after it is invented.

I was once thinking of a small story to write about several thousands years in the future of a religion / belief that something like "the force" reallxy exists - and its followers believe in George Lucas being some kind of prophet.

I thought the same about Ctulhu,

and a similar thing can be said of the number 42 as well.

It creates something like an aura, like a set of followers around itself, because people bother to think about it, thus put ebnergy into it, and even create threads like this here.

Maybe a few thousand years in the future the number 42 will have become a holy number like the number 7 is a holy number for several cultures.