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 high-
balls, 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 function, 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 boss appreciated that. They had no intention, originally, of
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