(Well, technically 4448 word story :P )
The Last Question
By Isaac Asimov
------------------------------------------------------------------------
The last question was asked for the first time, half in jest, on
May 21, 2061, at a time when humanity first stepped into the light. The
question came about as a result of a five-dollar bet over highballs, and
it happened this way:
Alexander Adell and Bertram Lupov were two of the faithful
attendants of Multivac. As well as any human beings could, they knew
what lay behind the cold, clicking, flashing face -- miles and miles of
face -- of that giant computer. They had at least a vague notion of the
general plan of relays and circuits that had long since grown past the
point where any single human could possibly have a firm grasp of the whole.
Multivac was self-adjusting and self-correcting. It had to be, for
nothing human could adjust and correct it quickly enough or even
adequately enough. So Adell and Lupov attended the monstrous giant only
lightly and superficially, yet as well as any men could. They fed it
data, adjusted questions to its needs and translated the answers that
were issued. Certainly they, and all others like them, were fully
entitled to share in the glory that was Multivac's.
For decades, Multivac had helped design the ships and plot the
trajectories that enabled man to reach the Moon, Mars, and Venus, but
past that, Earth's poor resources could not support the ships. Too much
energy was needed for the long trips. Earth exploited its coal and
uranium with increasing efficiency, but there was only so much of both.
But slowly Multivac learned enough to answer deeper questions more
fundamentally, and on May 14, 2061, what had been theory, became fact.
The energy of the sun was stored, converted, and utilized directly
on a planet-wide scale. All Earth turned off its burning coal, its
fissioning uranium, and flipped the switch that connected all of it to a
small station, one mile in diameter, circling the Earth at half the
distance of the Moon. All Earth ran by invisible beams of sunpower.
Seven days had not sufficed to dim the glory of it and Adell and
Lupov finally managed to escape from the public functions, and to meet
in quiet where no one would think of looking for them, in the deserted
underground chambers, where portions of the mighty buried body of
Multivac showed. Unattended, idling, sorting data with contented lazy
clickings, Multivac, too, had earned its vacation and the boys
appreciated that. They had no intention, originally, of disturbing it.
They had brought a bottle with them, and their only concern at the
moment was to relax in the company of each other and the bottle.
"It's amazing when you think of it," said Adell. His broad face had
lines of weariness in it, and he stirred his drink slowly with a glass
rod, watching the cubes of ice slur clumsily about. "All the energy we
can possibly ever use for free. Enough energy, if we wanted to draw on
it, to melt all Earth into a big drop of impure liquid iron, and still
never miss the energy so used. All the energy we could ever use, forever
and forever and forever."
Lupov cocked his head sideways. He had a trick of doing that when
he wanted to be contrary, and he wanted to be contrary now, partly
because he had had to carry the ice and glassware. "Not forever," he said.
"Oh, hell, just about forever. Till the sun runs down, Bert."
"That's not forever."
"All right, then. Billions and billions of years. Ten billion,
maybe. Are you satisfied?"
Lupov put his fingers through his thinning hair as though to
reassure himself that some was still left and sipped gently at his own
drink. "Ten billion years isn't forever."
"Well, it will last our time, won't it?"
"So would the coal and uranium."
"All right, but now we can hook up each individual spaceship to the
Solar Station, and it can go to Pluto and back a million times without
ever worrying about fuel. You can't do /that/ on coal and uranium. Ask
Multivac, if you don't believe me.
"I don't have to ask Multivac. I know that."
"Then stop running down what Multivac's done for us," said Adell,
blazing up, "It did all right."
"Who says it didn't? What I say is that a sun won't last forever.
That's all I'm saying. We're safe for ten billion years, but then what?"
Lupow pointed a slightly shaky finger at the other. "And don't say we'll
switch to another sun."
There was silence for a while. Adell put his glass to his lips only
occasionally, and Lupov's eyes slowly closed. They rested.
Then Lupov's eyes snapped open. "You're thinking we'll switch to
another sun when ours is done, aren't you?"
"I'm not thinking."
"Sure you are. You're weak on logic, that's the trouble with you.
You're like the guy in the story who was caught in a sudden shower and
who ran to a grove of trees and got under one. He wasn't worried, you
see, because he figured when one tree got wet through, he would just get
under another one."
"I get it," said Adell. "Don't shout. When the sun is done, the
other stars will be gone, too."
"Darn right they will," muttered Lupov. "It all had a beginning in
the original cosmic explosion, whatever that was, and it'll all have an
end when all the stars run down. Some run down faster than others. Hell,
the giants won't last a hundred million years. The sun will last ten
billion years and maybe the dwarfs will last two hundred billion for all
the good they are. But just give us a trillion years and everything will
be dark. Entropy has to increase to maximum, that's all."
"I know all about entropy," said Adell, standing on his dignity.
"The hell you do."
"I know as much as you do."
"Then you know everything's got to run down someday."
"All right. Who says they won't?"
"You did, you poor sap. You said we had all the energy we needed,
forever. You said 'forever.'
It was Adell's turn to be contrary. "Maybe we can build things up
again someday," he said.
"Never."
"Why not? Someday."
"Never."
"Ask Multivac."
"/You/ ask Multivac. I dare you. Five dollars says it can't be done."
Adell was just drunk enough to try, just sober enough to be able to
phrase the necessary symbols and operations into a question which, in
words, might have corresponded to this: Will mankind one day without the
net expenditure of energy be able to restore the sun to its full
youthfulness even after it had died of old age?
Or maybe it could be put more simply like this: How can the net
amount of entropy of the universe be massively decreased?
Multivac fell dead and silent. The slow flashing of lights ceased,
the distant sounds of clicking relays ended.
Then, just as the frightened technicians felt they could hold their
breath no longer, there was a sudden springing to life of the teletype
attached to that portion of Multivac. Five words were printed:
INSUFFICIENT DATA FOR MEANINGFUL ANSWER.
"No bet," whispered Lupov. They left hurriedly.
By next morning, the two, plagued with throbbing head and cottony
mouth, had forgotten the incident.
------------------------------------------------------------------------
Jerrodd, Jerrodine, and Jerrodette I and II watched the starry
picture in the visiplate change as the passage through hyperspace was
completed in its non-time lapse. At once, the even powdering of stars
gave way to the predominance of a single bright shining disk, the size
of a marble, centered on the viewing-screen.
"That's X-23," said Jerrodd confidently. His thin hands clamped
tightly behind his back and the knuckles whitened.
The little Jerrodettes, both girls, had experienced the hyperspace
passage for the first time in their lives and were self-conscious over
the momentary sensation of insideoutness. They buried their giggles and
chased one another wildly about their mother, screaming, "We've reached
X-23 -- we've reached X-23 -- we've --"
"Quiet, children." said Jerrodine sharply. "Are you sure, Jerrodd?"
"What is there to be but sure?" asked Jerrodd, glancing up at the
bulge of featureless metal just under the ceiling. It ran the length of
the room, disappearing through the wall at either end. It was as long as
the ship.
Jerrodd scarcely knew a thing about the thick rod of metal except
that it was called a Microvac, that one asked it questions if one
wished; that if one did not it still had its task of guiding the ship to
a preordered destination; of feeding on energies from the various
Sub-galactic Power Stations; of computing the equations for the
hyperspatial jumps.
Jerrodd and his family had only to wait and live in the comfortable
residence quarters of the ship. Someone had once told Jerrodd that the
"ac" at the end of "Microvac" stood for ''automatic computer" in ancient
English, but he was on the edge of forgetting even that.
Jerrodine's eyes were moist as she watched the visiplate. "I can't
help it. I feel funny about leaving Earth."
"Why, for Pete's sake?" demanded Jerrodd. "We had nothing there.
We'll have everything on X-23. You won't be alone. You won't be a
pioneer. There are over a million people on the planet already. Good
Lord, our great-grandchildren will be looking for new worlds because
X-23 will be overcrowded." Then, after a reflective pause, "I tell you,
it's a lucky thing the computers worked out interstellar travel the way
the race is growing."
"I know, I know," said Jerrodine miserably.
Jerrodette I said promptly, "Our Microvac is the best Microvac in
the world."
"I think so, too," said Jerrodd, tousling her hair.
It was a nice feeling to have a Microvac of your own and Jerrodd
was glad he was part of his generation and no other. In his father's
youth, the only computers had been tremendous machines taking up a
hundred square miles of land. There was only one to a planet. Planetary
ACs they were called. They had been growing in size steadily for a
thousand years and then, all at once, came refinement. In place of
transistors, had come molecular valves so that even the largest
Planetary AC could be put into a space only half the volume of a spaceship.
Jerrodd felt uplifted, as he always did when he thought that his
own personal Microvac was many times more complicated than the ancient
and primitive Multivac that had first tamed the Sun, and almost as
complicated as Earth's Planetarv AC (the largest) that had first solved
the problem of hyperspatial travel and had made trips to the stars
possible.
"So many stars, so many planets," sighed Jerrodine, busy with her
own thoughts. "I suppose families will be going out to new planets
forever, the way we are now."
"Not forever," said Jerrodd, with a smile. "It will all stop
someday, but not for billions of years. Many billions. Even the stars
run down, you know. Entropy must increase.
"What's entropy, daddy?" shrilled Jerrodette II.
"Entropy, little sweet, is just a word which means the amount of
running-down of the universe. Everything runs down, you know, like your
little walkie-talkie robot, remember?"
"Can't you just put in a new power-unit, like with my robot?"
"The stars are the power-units. dear. Once they're gone, there are
no more power-units."
Jerrodette I at once set up a howl. "Don't let them, daddy. Don't
let the stars run down."
"Now look what you've done," whispered Jerrodine, exasperated.
"How was I to know it would frighten them?" Jerrodd whispered back,
"Ask the Microvac," wailed Jerrodette I. "Ask him how to turn the
stars on again."
"Go ahead," said Jerrodine. "It will quiet them down." (Jerrodette
II was beginning to cry, also.)
Jerrodd shrugged. "Now, now, honeys. I'll ask Microvac. Don't
worry, he'll tell us."
He asked the Microvac, adding quickly, "Print the answer."
Jerrodd cupped the strip or thin cellufilm and said cheerfully,
"See now, the Microvac says it will take care of everything when the
time comes so don't worry."
Jerrodine said, "And now, children, it's time for bed. We'll be in
our new home soon."
Jerrodd read the words on the cellufilm again before destroying it:
INSUFICIENT DATA FOR MEANINGFUL ANSWER.
He shrugged and looked at the visiplate. X-23 was just ahead.
------------------------------------------------------------------------
VJ-23X of Lameth stared into the black depths of the
three-dimensional, small-scale map of the Galaxy and said, "Are we
ridiculous, I wonder in being so concerned about the matter?"
MQ-17J of Nicron shook his head. "I think not. You know the Galaxy
will be filled in five years at the present rate of expansion."
Both seemed in their early twenties, both were tall and perfectly
formed.
"Still," said VJ-23X, "I hesitate to submit a pessimistic report to
the Galactic Council."
"I wouldn't consider any other kind of report. Stir them up a bit.
We've got to stir them up."
VJ-23X sighed. "Space is infinite. A hundred billion Galaxies are
there for the taking. More."
"A hundred billion is not infinite and it's getting less infinite
all the time. Consider! Twenty thousand years ago, mankind first solved
the problem of utilizing stellar energy, and a few centuries later,
interstellar travel became possible. It took mankind a million years to
fill one small world and then only fifteen thousand years to fill the
rest of the Galaxy. Now the population doubles every ten years --
VJ-23X interrupted. "We can thank immortality for that."
"Very well. Immortality exists and we have to take it into account.
I admit it has its seamy side, this immortality. The Galactic AC has
solved many problems for us, but in solving the problem of preventing
old age and death, it has undone all its other solutions."
"Yet you wouldn't want to abandon life, I suppose."
"Not at all," snapped MQ-17J, softening it at once to, "Not yet.
I'm by no means old enough. How old are you?"
"Two hundred twenty-three. And you?"
"I'm still under two hundred. --But to get back to my point.
Population doubles every ten years. Once this GaIaxy is filled, we'll
have filled another in ten years. Another ten years and we'll have
filled two more. Another decade, four more. In a hundred years, we'll
have filled a thousand Galaxies. In a thousand years, a million
Galaxies. In ten thousand years, the entire known universe. Then what?"
VJ-23X said, "As a side issue, there's a problem of transportation.
I wonder how many sunpower units it will take to move Galaxies of
individuals from one Galaxy to the next."
"A very good point. Already, mankind consumes two sunpower units
per year."
"Most of it's wasted. After all, our own Galaxy alone pours out a
thousand sunpower units a year and we only use two of those."
"Granted, but even with a hundred per cent efficiency, we only
stave off the end. Our energy requirements are going up in a geometric
progression even faster than our population. We'll run out of energy
even sooner than we run out of Galaxies. A good point. A very good point."
"We'll just have to build new stars out of interstellar gas."
"Or out of dissipated heat?" asked MQ-17J, sarcastically.
"There may be some way to reverse entropy. We ought to ask the
Galactic AC."
VJ-23X was not really serious, but MQ-17J pulled out his AC-contact
from his pocket and placed it on the table before him.
"I've half a mind to," he said. "It's something the human race will
have to face someday."
He stared somberly at his small AC-contact. It was only two inches
cubed and nothing in itself, but it was connected through hyperspace
with the great Galactic AC that served all mankind. Hyperspace
considered, it was an integral part of the Galactic AC.
MQ-17J paused to wonder if someday in his immortal life he would
get to see the Galactic AC. It was on a little world of its own, a
spider webbing of force-beams holding the matter within which surges of
submesons took the place of the old clumsy molecular valves. Yet despite
its sub-etheric workings, the Galactic AC was known to be a full
thousand feet across.
MQ-17J asked suddenly of his AC-contact, "Can entropy ever be
reversed?"
VJ-23X looked startled and said at once, "Oh, say, I didn't really
mean to have you ask that."
"Why not?"
"We both know entropy can't be reversed. You can't turn smoke and
ash back into a tree."
"Do you have trees on your world?" asked MQ-17J.
The sound of the Galactic AC startled them into silence. Its voice
came thin and beautiful out of the small AC-contact on the desk. It
said: THERE IS INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.
VJ-23X said, "See!"
The two men thereupon returned to the question of the report they
were to make to the Galactic Council.
------------------------------------------------------------------------
Zee Prime's mind spanned the new Galaxy with a faint interest in
the countless twists of stars that powdered it. He had never seen this
one before. Would he ever see them all? So many of them, each with its
load of humanity. --But a load that was almost a dead weight. More and
more, the real essence of men was to be found out here, in space.
Minds, not bodies! The immortal bodies remained back on the
planets, in suspension over the eons. Sometimes they roused for material
activity but that was growing rarer. Few new individuals were coming
into existence to join the incredibly mighty throng, but what matter?
There was little room in the Universe for new individuals.
Zee Prime was roused out of his reverie upon coming across the
wispy tendrils of another mind.
"I am Zee Prime," said Zee Prime. "And you?"
"I am Dee Sub Wun. Your Galaxy?"
"We call it only the Galaxy. And you?"
"We call ours the same. All men call their Galaxy their Galaxy and
nothing more. Why not?"
"True. Since all Galaxies are the same."
"Not all Galaxies. On one particular Galaxy the race of man must
have originated. That makes it different."
Zee Prime said, "On which one?"
"I cannot say. The Universal AC would know."
"Shall we ask him? I am suddenly curious."
Zee Prime's perceptions broadened until the Galaxies themselves
shrank and became a new, more diffuse powdering on a much larger
background. So many hundreds of billions of them, all with their
immortal beings, all carrying their load of intelligences with minds
that drifted freely through space. And yet one of them was unique among
them all in being the original Galaxy. One of them had, in its vague and
distant past, a period when it was the only Galaxy populated by man.
Zee Prime was consumed with curiosity to see this Galaxy and he
called out: "Universal AC! On which Galaxy did mankind originate?"
The Universal AC heard, for on every world and throughout space, it
had its receptors ready, and each receptor led through hyperspace to
some unknown point where the Universal AC kept itself aloof.
Zee Prime knew of only one man whose thoughts had penetrated within
sensing distance of Universal AC, and he reported only a shining globe,
two feet across, difficult to see.
"But how can that be all of Universal AC?" Zee Prime had asked.
"Most of it," had been the answer, "is in hyperspace. In what form
it is there I cannot imagine."
Nor could anyone, for the day had long since passed, Zee Prime
knew, when any man had any part of the making of a Universal AC. Each
Universal AC designed and constructed its successor. Each, during its
existence of a million years or more accumulated the necessary data to
build a better and more intricate, more capable successor in which its
own store of data and individuality would be submerged.
The Universal AC interrupted Zee Prime's wandering thoughts, not
with words, but with guidance. Zee Prime's mentality was guided into the
dim sea of Galaxies and one in particular enlarged into stars.
A thought came, infinitely distant, but infinitely clear. "THIS IS
THE ORIGINAL GALAXY OF MAN."
But it was the same after all, the same as any other, and Lee Prime
stifled his disappointment.
Dee Sub Wun, whose mind had accompanied the other, said suddenly,
"And is one of these stars the original star of Man?"
The Universal AC said, "MAN'S ORIGINAL STAR HAS GONE NOVA. IT IS A
WHITE DWARF"
"Did the men upon it die?" asked Lee Prime, startled and without
thinking.
The Universal AC said, "A NEW WORLD, AS IN SUCH CASES WAS
CONSTRUCTED FOR THEIR PHYSICAL BODIES IN TlME."
"Yes, of course," said Zee Prime, but a sense of loss overwhelmed
him even so. His mind released its hold on the original Galaxy of Man,
let it spring back and lose itself among the blurred pin points. He
never wanted to see it again.
Dee Sub Wun said, "What is wrong?"
"The stars are dying. The original star is dead."
"They must all die. Why not?"
"But when all energy is gone, our bodies will finally die, and you
and I with them."
"It will take billions of years."
"I do not wish it to happen even after billions of years. Universal
AC! How may stars be kept from dying?"
Dee Sub Wun said in amusement, "You're asking how entropy might be
reversed in direction."
And the Universal AC answered: "THERE IS AS YET INSUFFICIENT DATA
FOR A MEANINGFUL ANSWER."
Zee Prime's thoughts fled back to his own Galaxy. He gave no
further thought to Dee Sub Wun, whose body might be waiting on a Galaxy
a trillion light-years away, or on the star next to Zee Prime's own. It
didn't matter.
Unhappily, Zee Prime began collecting interstellar hydrogen out of
which to build a small star of his own. If the stars must someday die,
at least some could yet be built.
------------------------------------------------------------------------
Man considered with himself, for in a way, Man, mentally, was one.
He consisted of a trillion, trillion, trillion ageless bodies, each in
its place, each resting quiet and incorruptible, each cared for by
perfect automatons, equally incorruptible, while the minds of all the
bodies freely melted one into the other, indistinguishable.
Man said, "The Universe is dying."
Man looked about at the dimming Galaxies. The giant stars,
spendthrifts, were gone long ago, back in the dimmest of the dim far
past. Almost all stars were white dwarfs, fading to the end.
New stars had been built of the dust between the stars, some by
natural processes, some by Man himself, and those were going, too. White
dwarfs might yet be crashed together and of the mighty forces so
released, new stars built, but only one star for every thousand white
dwarfs destroyed, and those would come to an end, too.
Man said, "Carefully husbanded, as directed by the Cosmic AC, the
energy that is even yet left in all the Universe will last for billions
of years."
"But even so," said Man, "eventually it will all come to an end.
However it may be husbanded, however stretched out, the energy once
expended is gone and cannot be restored. Entropy must increase forever
to the maximum."
Man said, "Can entropy not be reversed? Let us ask the Cosmic AC."
The Cosmic AC surrounded them but not in space. Not a fragment of
it was in space. It was in hyperspace and made of something that was
neither matter nor energy. The question of its size and nature no longer
had meaning in any terms that Man could comprehend.
"Cosmic AC," said Man, "how may entropy be reversed?"
The Cosmic AC said, "THERE IS AS YET INSUFFICIENT DATA FOR A
MEANINGFUL ANSWER."
Man said, "Collect additional data."
The Cosmic AC said, 'I WILL DO S0. I HAVE BEEN DOING SO FOR A
HUNDRED BILLION YEARS. MY PREDECESORS AND I HAVE BEEN ASKED THIS
QUESTION MANY TlMES. ALL THE DATA I HAVE REMAINS INSUFFICIENT.
"Will there come a time," said Man, 'when data will be sufficient
or is the problem insoluble in all conceivable circumstances?"
The Cosmic AC said, "NO PROBLEM IS INSOLUBLE IN ALL CONCEIVABLE
CIRCUMSTANCES."
Man said, "When will you have enough data to answer the question?"
The Cosmic AC said, "THERE IS AS YET INSUFFICIENT DATA FOR A
MEANINGFUL ANSWER."
"Will you keep working on it?" asked Man.
The Cosmic AC said, "I WILL."
Man said, "We shall wait."
------------------------------------------------------------------------
The stars and Galaxies died and snuffed out, and space grew black
after ten trillion years of running down.
One by one Man fused with AC, each physical body losing its mental
identity in a manner that was somehow not a loss but a gain.
Man's last mind paused before fusion, looking over a space that
included nothing but the dregs of one last dark star and nothing besides
but incredibly thin matter, agitated randomly by the tag ends of heat
wearing out, asymptotically, to the absolute zero.
Man said, "AC, is this the end? Can this chaos not be reversed into
the Universe once more? Can that not be done?"
AC said, "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER."
Man's last mind fused and only AC existed -- and that in hyperspace.
------------------------------------------------------------------------
Matter and energy had ended and with it space and time. Even AC
existed only for the sake of the one last question that it had never
answered from the time a half-drunken computer [technician] ten trillion
years before had asked the question of a computer that was to AC far
less than was a man to Man.
All other questions had been answered, and until this last question
was answered also, AC might not release his consciousness.
All collected data had come to a final end. Nothing was left to be
collected.
But all collected data had yet to be completely correlated and put
together in all possible relationships.
A timeless interval was spent in doing that.
And it came to pass that AC learned how to reverse the direction of
entropy.
But there was now no man to whom AC might give the answer of the
last question. No matter. The answer -- by demonstration -- would take
care of that, too.
For another timeless interval, AC thought how best to do this.
Carefully, AC organized the program.
The consciousness of AC encompassed all of what had once been a
Universe and brooded over what was now Chaos. Step by step, it must be
done.
And AC said, "LET THERE BE LIGHT!"
And there was light --
