Home > Math News Archive Detail

<< Prev 12/30/2007 Next >>

The Answer is 42

At the end of a calendar year, it's appropriate to focus on the number 42. Afterall, 42 is the Answer to the Great Question in Life, the Universe, and Everything...at least according to Douglas Adams' Hitchhiker's Guide to the Galaxy.

But why 42? First, it's the Answer produced by the hypercomputer Deep Thought... after 7.5 million years of computations. But what's the Question? Alas, Deep Thought wasn't sophisticated enough to go beyond the answer 42.

Some have claimed that the Answer is 42 because 6 9 = 42 in base 13. Adams response: "Nobody writes jokes in base 13."

So why is 42 special...maybe its because:

  • 42 was a sacred number in Tibet and a Hindu god had 42 arms
  • Square the product of 42 and any prime number (>10)...the result always has exactly 81 divisors
  • 42 is the magic sum for a magic cube using the numbers 1-27
  • 42 is the fifth Catalan number
  • 42 aspects of personality are revealed by phrenological head bumps
  • 42 degrees is the angle measure between the elevation of a rainbow and one's shadow
  • 42 days is the gestation period for a ferret
  • 42 kilometers was the length of the Berlin Wall
  • 42 minutes is the time needed for an object to fall through a frictionless tunnel bored through the center of the earth
  • a dog has 42 teeth
Over the years, Adams has rejected all theories as to "why 42?" On November 3, 1993, he said: "The answer to this is very simple. It was a joke. It had to be a number, an ordinary, smallish number, and I chose that one. Binary representations, base thirteen, Tibetan monks are all complete nonsense. I sat at my desk, stared into the garden and thought '42 will do.' I typed it out. End of story."

Source: Used many sources: Henry (1985), Wells (1986), Hartston (1997), Wikipedia