42 (number) - Definition and Overview

42 is the natural number following 41 and followed by 43.

In mathematics

This composite number's factorization makes it a sphenic number. It is also the third 15-gonal number, a Catalan number, a meandric number, an open meandric number, a Harshad number and a self number. It is bracketed by twin primes.

In science

• The atomic number of molybdenum
• The visual angle between the colored part of a rainbow and the center point of its arc (where your head's shadow would be projected to) is 42 degrees.
• If you drilled a straight tunnel through any part of the Earth, including (but not limited to) straight through the middle, and let go of an object right at the mouth of the tunnel, the time it would take the object to fall or roll to the other end of the tunnel by gravity alone (assuming no friction) is 42 minutes.

In astronomy,

Messier object M42, a magnitude 5.0 diffuse nebula in the constellation Orion, also known as the Orion Nebula

The New General Catalogue object (http://www.ngcic.org/) NGC 42, a spiral galaxy in the constellation Pegasus

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/SEsaros/SEsaros1-175.html) of the solar eclipse series which began on 1577 BC April 28 and ended on 297 BC June 5. The duration of Saros series 42 was 1280.1 years, and it contained 72 solar eclipses.

The Saros number (http://sunearth.gsfc.nasa.gov/eclipse/LEsaros/LEsaros1-175.html) of the lunar eclipse series which began on 1293 BC January 24 and ended on 59 April 15. The duration of Saros series 42 was 1352.2 years, and it contained 76 lunar eclipses.

In other fields

In religion:

• The number of men of Beth-azmaveth in the Census of men of Israel upon return from exile. (Holy Bible, Ezra 2:24)
• The number of months the Beast will hold dominion over the Earth. (Holy Bible, Revelation 13:5)
• The number of generations recorded between Abraham and Jesus in the Gospel of Matthew. (Holy Bible, Matthew 1:17)
• The maximum total number received of any one present in the song The Twelve Days of Christmas.
• There are 42 principles of Ma'at.

Forty-two is also:

• The answer to the Ultimate Question of Life, the Universe and Everything, according to Douglas Adams' book The Hitchhiker's Guide to the Galaxy. However, the unanswered quandary was then: What was the question, exactly? The popularity of this book has made this number pop up in many unexpected contexts, usually inserted by fans; for instance, it is used as an identifier at the beginning of every TIFF-file. The official TIFF specification says, "this value was chosen for its deep philosophical significance."

• In Lewis Carroll's book The Hunting of the Snark, (before Douglas Adams' book was written) the baker left 42 pieces of luggage on the pier. Lewis Carroll was strangely fascinated by this number. For more references, read The Annotated Alice.
• The sum of the numbers or spots on a pair of conventional (six-sided) dice.
• The name of a Texan trick-taking game played with dominoes (see 42 (dominoes)).
• The number of the French department Loire.
• The minimum age one had to have to be elected a consul in the Roman Republic.
• The jersey number of Jackie Robinson, which is retired by all Major League Baseball teams.
• The jersey number of Pat Tillman, which was retired on November 13, 2004 by Arizona State University.
• The number of distinct types of cheese requested in Monty Python's Cheese Shop sketch.
• One barrel of oil is equivalent to 42 gallons of oil.
• Wolves and dogs (Canines) have 42 teeth.
• Part of the name of:
  • 42 BELOW, a vodka produced in New Zealand.
  • Level 42, the name of a band (named after the Hitchhikers usage).
• The year A.D. 42, 42 BC, and 1942.