It’s not uncommon for famous authors of “adult” literature to have also penned lesser-known but no less lovely children’s books — take, for instance, those by Mark Twain, Maya Angelou, James Joyce, E. E. Cummings, and Sylvia Plath. Famous scientists, on the other hand, are more likely to become the subject of a children’s book rather than the author of one. But not so with Stephen Hawking, one of the great geniuses of our time, born on this day in 1942.

In 2007, Hawking wrote George’s Secret Key to the Universe (public library | IndieBound) — a charming, imaginative story about the mesmerism of space and the allure of time-travel, featuring lovely semi-Sendakian crosshatch illustrations by Garry Parsons. What makes the book especially endearing is that Hawking co-wrote it with his daughter Lucy.

One morning, George — a little boy raised by lo-fi, bookish parents who believe technology is evil — discovers that his pet pig Freddy has disappeared. Befuddled, he traces Freddy’s hoofprints to the neighboring house, where he meets a scientist named Greg and his daughter Annie.

Greg warms George up to science — “Science is a wonderful and fascinating subject that helps us understand the world around us and all its marvels,” he says as he shows the boy the enchanting science behind everyday phenomena in the kitchen — and introduces him to his own “pet” of sorts, Cosmos. Cosmos is the world’s most powerful computer and not only speaks but can also empower approved users to travel across space-time.

George is enormously excited about the prospect of time-travel, but he first needs to take the Oath of the Scientist — a promise to only use scientific knowledge for good — in order to become approved.

And so begin the adventures, on which George encounters black holes (and learns — of course! — about how Hawking radiation makes them slowly disintegrate) and floats across four billion years.

George’s Secret Key to the Universe is bound to tickle curious young readers into falling in love with science. Complement it with Hawking’s theory of everything, animated in 150 seconds, then revisit this fantastic 1991 Errol Morris documentary about Hawking.