From 1941 to 1949, Isaac Asimov wrote a series of science fiction stories about the decline and fall of a Galactic Empire. These stories were published in the magazine Astounding Stories, and in 1950 were reprinted in three volumes titled Foundation, Foundation and Empire, and Second Foundation. Collectively, the three volumes became known as the Foundation Trilogy.

When the first four stories were assembled into the book Foundation, the editor complained that the story began too abruptly, and asked Asimov to write a fifth story to precede the other four. Asimov complied, producing an account of how mathematician Hari Seldon establishes two Foundations at opposite ends of the galaxy to preserve the knowledge of the human race and serve as nuclei for the formation of a Second Empire. At one point in the story, Seldon is shown using the tool of his trade:

Seldon removed his calculator pad from the pouch at his belt. Men said he kept one beneath his pillow for use in moments of wakefulness. Its gray, glossy finish was slightly worn by use. Seldon’s nimble fingers, spotted now with age, played along the hard plastic that rimmed it. Red symbols glowed out from the gray.

In 1950, the standard calculation tool used by mathematicians and engineers was the slide rule, but Asimov described a future in which the slide rule was replaced by something new: a handheld electronic device.

As luck would have it, I read the Foundation Trilogy for the first time in the early 1970s, just as the first pocket calculators were appearing in stores. They looked exactly like what Asimov described, right down to the belt pouches and glowing red symbols (the earliest calculators had displays that used red LEDs). Two decades before its invention, he had predicted the calculator with virtually perfect accuracy. And it did completely replace the slide rule.

A few years later, Asimov wrote a short story (“The Feeling of Power”) in which pocket calculators are so ubiquitous that people have forgotten how to perform calculations without them. This idea seemed farfetched in 1958, but today, it’s very plausible.

I should also mention that Asimov himself was a fan of the slide rule, which is not too surprising for someone who studied math and science, and received M.A. and Ph.D degrees in chemistry in the 1940s. He even wrote a book about it, An Easy Introduction to the Slide Rule, which was published in 1965. Ironically, when the pocket calculators drove the slide rule into extinction, Asimov’s book went out of print.