Phrases From The Hitchhiker's Guide To The Galaxy - Answer To The Ultimate Question of Life, The Universe, and Everything (42)

Answer To The Ultimate Question of Life, The Universe, and Everything (42)

In the first novel and radio series, a group of hyper-intelligent pan-dimensional beings demand to learn the Answer to the Ultimate Question of Life, The Universe, and Everything from the supercomputer, Deep Thought, specially built for this purpose. It takes Deep Thought 7½ million years to compute and check the answer, which turns out to be 42. The Ultimate Question itself is unknown.

When asked to produce The Ultimate Question, Deep Thought says that it cannot; however, it can help to design an even more powerful computer, the Earth, that can. The programmers then embark on a further ten-million-year program to discover The Ultimate Question. This new computer will incorporate living beings in the "computational matrix", with the pan-dimensional creators assuming the form of mice. The process is hindered after eight million years by the unexpected arrival on Earth of the Golgafrinchans and then is ruined completely, five minutes before completion, when the Earth is destroyed by the Vogons to make way for a new Hyperspace Bypass. This is later revealed to have been a ruse: the Vogons had been hired to destroy the Earth by a consortium of psychiatrists, led by Gag Halfrunt, who feared for the loss of their careers when the meaning of life became known.

Lacking a real question, the mice decide not to go through the whole thing again and settle for the out-of-thin-air suggestion "How many roads must a man walk down?" from Bob Dylan's song "Blowin' in the Wind".

At the end of the radio series (and television series, as well as the novel The Restaurant at the End of the Universe) Arthur Dent, having escaped the Earth's destruction, potentially has some of the computational matrix in his brain. He attempts to discover The Ultimate Question by extracting it from his brainwave patterns, as abusively suggested by Ford Prefect, when a Scrabble-playing caveman spells out forty two. Arthur pulls random letters from a bag, but only gets the sentence "What do you get if you multiply six by nine?"

"Six by nine. Forty two."

"That's it. That's all there is."

"I always thought something was fundamentally wrong with the universe"

Six times nine is, of course, fifty-four. The program on the "Earth computer" should have run correctly, but the unexpected arrival of the Golgafrinchans on prehistoric Earth caused input errors into the system—computing (because of the garbage in, garbage out rule) the wrong question—the question in Arthur's subconscious being invalid all along.

Quoting Fit the Seventh of the radio series, on Christmas Eve, 1978:

Narrator: There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.

Some readers subsequently noticed that 6₁₃ × 9₁₃ = 42₁₃ (using base 13). Douglas Adams later joked about this observation, saying, "I may be a sorry case, but I don't write jokes in base 13."

In Life, the Universe and Everything, Prak, a man who knows all that is true, confirms that 42 is indeed The Answer, and confirms that it is impossible for both The Answer and The Question to be known about in the same universe (compare the uncertainty principle) as they will cancel each other out and take the Universe with them to be replaced by something even more bizarre (as described in the first theory) and that it may have already happened (as described in the second). Though the question is never found, 42 is shown as the table number at which Arthur and his friends sit when they arrive at Milliways at the end of the radio series. Likewise, Mostly Harmless ends when Arthur stops at a street address identified by his cry of, "There, number 42!" and enters the club Beta, owned by Stavro Mueller, who is apparently the incarnation of Agrajag located at Stavromula Beta. Shortly after, the earth is destroyed in all existing incarnations.