Why do landmasses “sag” toward the south pole, as on the Sherwin-Williams paint logo? In 1973 Ormonde de Kay Jr., a fellow of the Royal Geographical Society, proposed a “theory of continental drip”:

“Let’s look at the world map. Africa and South America … are textbook examples of drip, with their broad tops and tapering lower extremities. But so is North America, with Baja California and Florida dangling down at its sides, and Greenland, too, clearly shows the characteristics of drip.”

“What causes continental drip? A few possible explanations come to mind: some palaeomagnetic force, for example, unsuspected and therefore undetected, centered in massive, mountainous Antarctica and perpetually tugging at the lower hems of land masses. Or drip might somehow be the result of the Earth’s rotation, or of lunar attraction. One conclusion, however, would seem inescapable: contrary to the teachings of science, but as every schoolchild has always known, north really is up, and south down!”

German arithmetician Zacharias Dase (1824-1861) once multiplied two 100-digit numbers in his head. It took him 8 hours 45 minutes.

Karl Gauss estimated that even a skilled mathematician, using pencil and paper, would require fully half that time.

“This coffee plunges into the stomach … the mind is aroused, and ideas pour forth like the battalions of the Grand Army on the field of battle.” So wrote Balzac, who wrote for up to 15 hours a day wired on black coffee.

If anything, he was ahead of his time. Today we drink more than 400 billion cups of coffee every year, making it the world’s most popular beverage. It’s second only to oil as the world’s largest traded commodity.

So, is it safe to consume that much of anything? Well, yes and no.

Generally, one dose of caffeine is 100 mg. That’s what you’d get in one shot of espresso, 5 ounces of coffee, or 2.5 cans of soda. The lowest dose that’s ever killed someone is 32 times that — and that was delivered intravenously. Even with strong coffee, you’d have to drink 3 cups an hour for 100 hours even to come close to killing yourself.

But that’s not all that can happen. At lower doses you might develop “caffeinism,” a condition that mimics mental illnesses ranging from anxiety and bipolar disorder to schizophrenia and psychosis.

(And that’s just humans. Dogs, horses and parrots have much more trouble metabolizing caffeine, and it hits spiders harder than even LSD, marijuana, benzedrine and chloral hydrate, as you can see here.)

And, as always, there’s no accounting for craziness. Jason Allen, a student at a North Carolina community college, died after swallowing almost 90 pills — about 18 grams of pure caffeine. That’s the equivalent of about 250 cups of coffee, a gallon and a half of espresso, or 22 gallons of Mountain Dew. That’s a serious all-nighter.

On Dec. 17, 2004, Alexis Lemaire computed the 13th root of a 100-digit number in his head.

He gave the correct answer — 45,792,573 — in 3.625 seconds.

The Indian mathematical prodigy Srinivasa Ramanujan showed an almost supernatural facility with numbers. British mathematician G.H. Hardy once visited him in the hospital:

I had ridden in taxicab number 1729 and remarked that the number seemed to me rather a dull one, and that I hoped it was not an unfavorable omen. “No,” he replied, “it is a very interesting number; it is the smallest number expressible as the sum of two cubes in two different ways.”

“Every positive integer,” remarked J.E. Littlewood, “is one of Ramanujan’s personal friends.”