From Hitchhiker’s Guide to the Galaxy:

“O Deep Thought Computer,” he said, “the task we have designed you to perform is this. We want you to tell us …” he paused, “…the Answer!”

“The answer?” said Deep Thought. “The answer to what?”

“Life!” urged Fook.

“The Universe!” said Lunkwill.

“Everything!” they said in chorus.

Deep Thought paused for a moment’s reflection.

“Tricky,” he said finally.

“But can you do it?”

Again, a significant pause.

“Yes,” said Deep Thought, “I can do it.”

“There is an answer?” said Fook with breathless excitement.”

“A simple answer?” added Lunkwill.

“Yes,” said Deep Thought. “Life, the Universe, and Everything. There is an answer. But,” he added, “I’ll have to think about it.”

…

The hum level in the room suddenly increased as several ancillary bass driver units, mounted in sedately carved and varnished cabinet speakers around the room, cut in to give Deep Thought’s voice a little more power.

“All I wanted to say,” bellowed the computer, “is that my circuits are now irrevocably committed to calculating the answer to the Ultimate Question of Life, the Universe, and Everything –” he paused and satisfied himself that he now had everyone’s attention, before continuing more quietly, “but the programme will take me a little while to run.”

Fook glanced impatiently at his watch.

“How long?” he said.

“Seven and a half million years,” said Deep Thought.

Lunkwill and Fook blinked at each other.

“Seven and a half million years…!” they cried in chorus.

[…7.5 million years later…]

A man standing on a brightly dressed dais before the building which clearly dominated the square was addressing the crowd over a Tannoy.

“O people waiting in the Shadow of Deep Thought!” he cried out. “Honoured Descendants of Vroomfondel and Majikthise, the Greatest and Most Truly Interesting Pundits the Universe has ever known… The Time of Waiting is over!”

Wild cheers broke out amongst the crowd. Flags, streamers and wolf whistles sailed through the air. The narrower streets looked rather like centipedes rolled over on their backs and frantically waving their legs in the air.

“Seven and a half million years our race has waited for this Great and Hopefully Enlightening Day!” cried the cheer leader. “The Day of the Answer!”

Hurrahs burst from the ecstatic crowd.

“Never again,” cried the man, “never again will we wake up in the morning and think Who am I? What is my purpose in life? Does it really, cosmically speaking, matter if I don’t get up and go to work? For today we will finally learn once and for all the plain and simple answer to all these nagging little problems of Life, the Universe and Everything!”

…

“Seventy-five thousand generations ago, our ancestors set this program in motion,” the second man said, “and in all that time we will be the first to hear the computer speak.”

“An awesome prospect, Phouchg,” agreed the first man…

“We are the ones who will hear,” said Phouchg, “the answer to the great question of Life…!”

“The Universe…!” said Loonquawl.

“And Everything…!”

“Shhh,” said Loonquawl with a slight gesture, “I think Deep Thought is preparing to speak!”

There was a moment’s expectant pause whilst panels slowly came to life on the front of the console. Lights flashed on and off experimentally and settled down into a businesslike pattern. A soft low hum came from the communication channel.

“Good morning,” said Deep Thought at last.

“Er… Good morning, O Deep Thought,” said Loonquawl nervously, “do you have …er, that is …”

“An answer for you?” interrupted Deep Thought majestically. “Yes. I have.”

The two men shivered with expectancy. Their waiting had not been in vain.

“There really is one?” breathed Phouchg.

“There really is one,” confirmed Deep Thought.

“To Everything? To the great Question of Life, the Universe and Everything?”

“Yes.”

Both of the men had been trained for this moment, their lives had been a preparation for it, they had been selected at birth as those who would witness the answer, but even so they found themselves gasping and squirming like excited children.

“And you’re ready to give it to us?” urged Loonquawl. “I am.”

“Now?”

“Now,” said Deep Thought.

They both licked their dry lips.

“Though I don’t think,” added Deep Thought, “that you’re going to like it.”

“Doesn’t matter!” said Phouchg. “We must know it! Now!”

“Now?” inquired Deep Thought.

“Yes! Now …”

“All right,” said the computer and settled into silence again. The two men fidgeted. The tension was unbearable.

“You’re really not going to like it,” observed Deep Thought.

“Tell us!”

“All right,” said Deep Thought. “The Answer to the Great Question… ”

“Yes …!”

“Of Life, the Universe and Everything… ” said Deep Thought.

“Yes …!”

“Is… ” said Deep Thought, and paused.

“Yes …!”

“Is …”

“Yes …!!!…?”

“Forty-two,” said Deep Thought, with infinite majesty and calm.

It was a long time before anyone spoke.

Out of the corner of his eye Phouchg could see the sea of tense expectant faces down in the square outside.

“We’re going to get lynched aren’t we?” he whispered.

“It was a tough assignment,” said Deep Thought mildly.

“Forty-two!” yelled Loonquawl. “Is that all you’ve got to show for seven and a half million years’ work?”

“I checked it very thoroughly,” said the computer, “and that quite definitely is the answer. I think the problem, to be quite honest with you, is that you’ve never actually known what the question is.”

“But it was the Great Question! The Ultimate Question of Life, the Universe and Everything!” howled Loonquawl.

“Yes,” said Deep Thought with the air of one who suffers fools gladly, “but what actually is it?”

A slow stupefied silence crept over the men as they stared at the computer and then at each other.

“Well, you know, it’s just Everything… Everything… ” offered Phouchg weakly.

“Exactly!” said Deep Thought. “So once you do know what the question actually is, you’ll know what the answer means.”

“Oh terrific,” muttered Phouchg flinging aside his notebook and wiping away a tiny tear.

“Look, alright, alright,” said Loonquawl, “can you just please tell us the Question?”

“The Ultimate Question?”

“Yes!”

“Of Life, the Universe, and Everything?” “Yes!”

Deep Thought pondered this for a moment. “Tricky,” he said.

“But can you do it?” cried Loonquawl.

Deep Thought pondered this for another long moment.

Finally: “No,” he said firmly.

Both men collapsed on to their chairs in despair.

“But I’ll tell you who can,” said Deep Thought.

They both looked up sharply.

“Who?” “Tell us!”

…

“I speak of none other than the computer that is to come after me,” intoned Deep Thought, his voice regaining its accustomed declamatory tones. “A computer whose merest operational parameters I am not worthy to calculate – and yet I will design it for you. A computer which can calculate the Question to the Ultimate Answer, a computer of such infinite and subtle complexity that organic life itself shall form part of its operational matrix. And you yourselves shall take on new forms and go down into the computer to navigate its ten-million-year program! Yes! I shall design this computer for you. And I shall name it also unto you. And it shall be called …The Earth.”

Phouchg gaped at Deep Thought.

“What a dull name,” he said and great incisions appeared down the length of his body. Loonquawl too suddenly sustained horrific gashes from nowhere. The Computer console blotched and cracked, the walls flickered and crumbled and the room crashed upwards into its own ceiling…