# 42 (number)

42
Cardinal forty-two
Ordinal 42nd
(forty-second)
Factorization 2 · 3 · 7
Divisors 1, 2, 3, 6, 7, 14, 21, 42
Roman numeral XLII
Unicode symbol(s) *
Binary 1010102
Octal 528
Duodecimal 3612

42 (forty-two) is the natural number following 41 and preceding 43. The number has received considerable attention in popular culture because of its appearance in The Hitchhiker's Guide to the Galaxy, as the "Answer to the Ultimate Question of Life, the Universe, and Everything".

## In mathematics

The 3 × 3 × 3 magic cube with rows summing to 42.
• Given 27 same-size cubes whose nominal values progress from 1 to 27, a 3×3×3 magic cube can be constructed such that every row, column, and corridor, and every diagonal passing through the center, comprises 3 cubes whose sum of values is 42.
• Forty-two is a pronic number and an abundant number; its prime factorization 2 · 3 · 7 makes it the second sphenic number and also the second of the form { 2 · 3 · r }. As with all sphenic numbers of this form, the aliquot sum is abundant by 12. 42 is also the second sphenic number to be bracketed by twin primes; 30 is also a pronic number and also rests between two primes. 42 has a 14 member aliquot sequence 42, 54, 66, 78, 90, 144, 259, 45, 33, 15, 9, 4, 3, 1, 0 and is itself part of the aliquot sequence commencing with the first sphenic number 30. Further, 42 is the 10th member of the 3-aliquot tree.
• It is a Catalan number. Consequently; 42 is the number of noncrossing partitions of a set of five elements, the number of triangulations of a heptagon, the number of rooted ordered binary trees with six leaves, the number of ways in which five pairs of nested parentheses can be arranged, etc.
• It is conjectured to be the scaling factor in the leading order term of the "sixth moment of the Riemann zeta function". In particular, Conrey & Ghosh have conjectured
${1 \over T}\int_0^T \left| \zeta\left({1 \over 2} + it\right) \right|^6\,dt \sim {42 \over 9!}\prod_p \left\{1-{1\over p}\right\}^4 \left( 1 + {4 \over p} + {1 \over p^2} \right) \log^9 T,$
where the infinite product is over all prime numbers, p.[1][2]
• Since the greatest prime factor of 422 + 1 = 1765 is 353 and thus more than 42 twice, 42 is a Størmer number.
• The eight digits of pi beginning from 242,422 places after the decimal point are 42424242.
• 42 is the expected number of throws of a (single) fair die until two sixes show up successively (for the first time).

## In science

• The atomic number of molybdenum.
• The angle in degrees for which a rainbow appears.
• In 1966, mathematician Paul Cooper theorized that the fastest, most efficient way to travel across continents would be to bore a straight hollow tube directly through the Earth, connecting a set of antipodes, evacuate it (remove the air), and then just fall through. The first half of the journey consists of free-fall acceleration, while the second half consists of an exactly equal deceleration. The time for such a journey works out to be 42 minutes. Remarkably, even if the tube does not pass through the exact center of the Earth, the time for a journey powered entirely by gravity always works out to be 42 minutes, as long as the tube remains friction-free, as while gravity's force would be lessened, so would the distance traveled at an equal rate.[5][6] (The same idea was proposed, without calculation, by Lewis Carroll in 1893 in Sylvie and Bruno Concluded.[7])

## In technology

• Magic numbers used by programmers:
• The glyph, or character, corresponding to the number 42 in the ASCII character set, is *, the asterisk, commonly known as the wildcard character. Depending on the usage, * can mean anything or everything. For example, when used as part of a regular expression, * means "matches any character"; when used in a Unix command such as "rm -fr /*", * means "everything".
• In the TIFF image file format, the second 16-bit word of every file is 42, which is used together with the first word to indicate byte order.
• In the reiser4 file system, 42 is the inode number of the root directory.
• Advanced Micro Device's One off Overlocking CPU was named Phenom 42, with the number being partially from the book The Hitchhikers Guide to the Galaxy.

## In religion

• There are 42 principles of Ma'at, the Ancient Egyptian personification of physical and moral law, order, and truth. In the judgement scene described in the Egyptian and the Book of the Coming/Going Forth by Day (the Book of the Dead (which evolved from the Coffin Texts and the Pyramid Texts)), there are 42 gods and goddesses of Egypt, personifying the principles of Ma'at, who ask questions of the departed, while Thoth records the answers, and the deceased's heart is weighed against the feather of Truth (Ma'at). These 42 correspond to the 42 Nomes (Governmental Units) of Egypt. If the departed successfully answers all 42, s/he becomes an Osiris.
• 42 is the number with which God creates the Universe in Kabalistic tradition. In Kabbalah, the most significant name is that of the En Sof (also known as "Ein Sof", "Infinite" or "Endless"), who is above the Sefirot (sometimes spelled "Sephirot").[9] The Forty-Two-Lettered Name contains four combined names which are spelled in Hebrew letters (spelled in letters = 42 letters), which is the name of Azilut (or "Atziluth" "Emanation"). While there are obvious links between the Forty-Two Lettered Name of the Babylonian Talmud (see further up this page) and the Kabbalah's Forty-Two Lettered Name, they are probably not identical because of the Kabbalah's emphasis on numbers. The Kabbalah also contains a Forty-Five Lettered Name and a Seventy-Two Lettered Name.
• In Judaism, the number (in the Babylonian Talmud, compiled 375 AD to 499 AD) of the "Forty-Two Lettered Name" ascribed to God. Rab (or Rabhs), a 3rd century source in the Talmud stated "The Forty-Two Lettered Name is entrusted only to him who is pious, meek, middle-aged, free from bad temper, sober, and not insistent on his rights". [Source: Talmud Kidduschin 71a, Translated by Rabbi Dr. I. Epstein]. Maimonides felt that the original Talmudic Forty-Two Lettered Name was perhaps composed of several combined divine names [Maimonides "Moreh"]. The apparently unpronouncable Tetragrammaton provides the backdrop from the Twelve-Lettered Name and the Forty-Two Lettered Name of the Talmud.
• In Western Hermetic sphere work 42 is the sum of the values of the 'true' spheres, 3,4,5,6,7,8 & 9 each of which represent one aspect of the body of God through which we observe the world. 1 and 2 are considered modalities of existence and 10 is the completion we see from our own sphere, 11. The sum of the squares of each of these numbers make 216, or 6 x 6 x 6, the number of the beast, which is also the number of the names of God the Jews had to say once a year in the holy of holies to assure blessings from on high. The 'beast' is the perfect sphere, represented in 3 dimensions by 3 bounding circles, each with 6 radii, hence 666 being the number of the beast and directly being linked to 216 and 42. This is the foundation of Western Hermetic sphere work and is echoed in Pythagoreanism. So it is fair and honest to say that 42 is genuinely the answer to 'Life the Universe and Everything', merely the uninitiated believe it to be a Douglas Adams joke!

## In popular culture

### In The Hitchhiker's Guide to the Galaxy

The number 42 is in the novel The Hitchhiker's Guide to the Galaxy by Douglas Adams. The Answer to the Ultimate Question of Life, the Universe, and Everything is calculated by an enormous supercomputer over a period of 7.5 million years to be 42. According to the novel Mostly Harmless, 42 is the street address of Stavromula Beta. In 1994, Adams created the 42 Puzzle, a game based on the number 42.

### In the works of Lewis Carroll

Lewis Carroll[10] made repeated use of this number in his writings.[11] (Likewise, Adams named the episodes of the original radio series of The Hitchhiker's Guide to the Galaxy "fits", the word Carroll used to name the chapters of The Hunting of the Snark).

Examples of Carroll's use of 42:

• Alice's Adventures in Wonderland has 42 illustrations.
• Rule Forty-two in Alice's Adventures in Wonderland ("All persons more than a mile high to leave the court".)
• Rule 42 of the Code in the preface to The Hunting of the Snark ("No one shall speak to the Man at the Helm.")
• In "fit the first" of The Hunting of the Snark the Baker had "forty-two boxes, all carefully packed, With his name painted clearly on each".
• Alice's recital of her "four times table" while falling down the rabbit hole makes sense if the first calculation is made in base 18, the second in base 21, and so on, increasing the base by three each time. Continuing on this pattern 4 × 12 would equal 19 in base 39, but 4 × 13 calculated in base 42, rather than providing the expected 20 would yield 1A. Hence, as Alice cries, "I shall never get to twenty at that rate!"
• The Red Queen announces her age as "one hundred and one, five years and a day", which - if the best possible date is assumed for the action of Through the Looking-Glass - gives a total of 37,044 days. With the further (textually unjustified) assumption that both Queens were born on the same day their combined age becomes 74,088 days, which is 42 x 42 x 42. Some commentators have asserted that this is deliberate on Carroll's part.[12]

### In television and film

• Fox Mulder, one of the main characters in The X-Files lived in Apartment 42 at 2630 Hegal Place, Alexandria, Virginia.[13]
• The Kumars at No. 42 television series. In 2003, Sanjeev Bhaskar hosted a BBC show nominating The Hitchhiker's Guide to the Galaxy as Britain's Best Loved Book.
• 42 is one of The Numbers - 4, 8, 15, 16, 23, and 42 - featured in Lost. It is also the number tied to the character "Kwon".
• A made for TV movie 42: Forty Two Up - an installment in a series of documentaries wherein the director revisits the same group of British-born individuals every 7 years.[14]
• 42 is an episode of Doctor Who, set in real time lasting approximately 42 minutes.
• In the Doctor Who episode Voyage of the Damned, the Tenth Doctor attempts to control a rogue host robot by randomly shouting numbers, including of course, 42.
• In an episode of the animated show, Phineas and Ferb called "The Fast & the Phineas", the boys turn their mother's car into a racecar. The number of their racecar is 42.
• 42 is the name of Buzz Lightyear's space ship from Pixar's animated science fiction series Buzz Lightyear of Star Command.
• In an episode of "House M.D" Dr. House claims that his favorite number is 42.
• In Monty Python's film And Now for Something Completely Different, the famous "How Not to be Seen" sketch is presented as "H.M. Government Public Service film No. 42".
• In A Clockwork Orange Alex browses through records in a record store and we see a record of the, at this time fictional, band Level 42.
• In an episode of "Stargate Atlantis" it is revealed that Rodney Mckay's password is made up of the birth years of several notable minds throughout history, and ends with the number 42. The character John Sheppard reveals that the number is the ultimate answer to life, the universe and everything, to the confusion of his alien companion.
• In an episode of "Stargate Atlantis," Season 4 - Doppelganger; Dr. McKay asks Col. Sheppard "Look, do you have any idea how many Gate addresses there are in the Ancient database that have no accompanying description?" to which Sheppard answers "forty two".
• In the episode "Human" from Stargate Universe, the key to a code appears to be the number 46. Upon seeing this, Daniel Jackson exclaims: "Well, it's not the ultimate answer to life, the universe and everything. That's forty two. Hitch Hikers Guide to the Galaxy."
• In "Finding Nemo" the address of the dentist's office is recited many times by Dory, it is P. Sherman, 42 Wallaby Way, Sydney
• In "The Mentalist", Season 2, Episode 21, titled "18-5-4", a fictional machine called the Universal Code Breaker or 'Universal Hack' , is hidden inside locker number 42.
• In "Amelie", the number appears on the bottom of Mr. Collignon's shoe.

### In video games

• 42 Entertainment is the company responsible for several alternate reality games, including I Love Bees, Year Zero and Why So Serious.
• In Spore, reaching the center of the galaxy yields a powerful item known as the "Staff of Life" which has a limited 42 uses. It also grants the player an achievement titled "42".
• In Fable II, the last in a series of ancient artifacts the player can find says "Now just think of the number 42."
• 101010 (42 in Binary) is an open-source Java game.
• In the Champions Online MMORPG it states during a loading screen "your lucky numbers are 2, 5 and 42"
• In Valve Corporation's Left 4 Dead 2, 42 is the number of Moustachios that must be shot in the Dark Carnival campaign's Whack-a-Mole style mini-game in order to unlock the STACH WACKER achievement.
• In Destroy All Humans! you go into a parody of Area 51 called Area 42.
• In Lego Batman, Lego Indiana Jones, and the Lego Star Wars games, the maximum amount of studs you can have is 4,200,000,000.
• In The Conduit one of the conspiracy messages reads XLII or 42 in roman numerals
• In Mucky Foot Software's 'Startopia', the AI Computer advisor is quoted as saying '42. Interesting number don't you think? Although I suppose its importance is lost on you carbon based lifeforms'

### In sports

Jackie Robinson in his now-retired number 42 jersey.

## References

1. ^ J. B. Conrey & A. Ghosh, "A conjecture for the sixth power moment of the Riemann zeta-function" International Mathematics Research Notices (1998)
2. ^ J. B. Conrey & S. M. Gonek, "High moments of the Riemann zeta-function" Duke Math J. 107 3 (2001): 577 – 604
3. ^ Alex Zhai ties for second-highest score in 2007 USA Mathematical Olympiad - By Andrew Lovdahl Gargoyle staff reporter Posted Monday, May 7, 2007, The OG, news & student awards - Online Gargoyle
4. ^ CBC News staff, "Canadian math champ's skills add up to a perfect score" CBC News July 20, 2004. "A 16-year-old Canadian was one of four students who achieved a perfect score at an international mathematics competition. Jacob Tsimerman of Toronto scored 42 out of 42, making him one of 45 individual gold medallists at the 45th International Mathematical Olympiad in Athens."
5. ^ "To Everywhere in 42 Minutes". Time. February 11, 1966. Retrieved 2008-05-18.
6. ^ "Jumping into a 7,965 mile deep hole". Retrieved 2008-05-18.
7. ^ Carroll, Lewis (29 December 1893). "Chapter 7". Sylvie and Bruno Concluded. 2. illustrated by Harry Furniss. United Kingdom: Macmillan and Co.. "Each railway is in a long tunnel, perfectly straight: so of cource the middle of it is nearer the centre of the globe than the two ends: so every train runs half-way down-hill, and that gives it force enough to run the other half up-hill."
8. ^ "Framework for practical hexagonal-image processing". Journal of Electronic Imaging 11 (104). 2002. doi:10.1117/1.1426078. Retrieved January 17, 2010 (abstract only).
9. ^ Primack, Joel; Nancy E. Abrams. "In A Beginning...Quantum Cosmology and Kabbalah" (PDF). Retrieved 2008-03-14.
10. ^ Lewis Carroll and Douglas Adams
11. ^ The Mystery of Lewis Carroll, Jenny Woolf
12. ^ What Lewis Carroll Taught Us: Alice's creator knew all about role-playing. by Seth Lerer, March 4, 2010
13. ^ Fox Mulder page on The X-Files Wikia http://x-files.wikia.com/wiki/Fox_Mulder
14. ^ 42: Forty Two Up at IMDB
15. ^ Allpar: Richard Petty and a history of Petty Racing
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