When: The Scientific Secrets of Perfect Timing(52)
7.
THINKING IN TENSES
A Few Final Words
Time flies like an arrow. Fruit flies like a banana.
—GROUCHO MARX (maybe)
The wisecrack that opens this chapter makes me laugh every time. It’s classic Groucho, a language-twisting, brain-bending quip in the tradition of “Outside of a dog, a book is a man’s best friend. Inside of a dog, it’s too dark to read.”1 Unfortunately, Julius Henry Marx, who became the most famous Marx brother, probably never said it. But the true history of the remark, and the surprisingly complex thought it embodies, offers one final idea for this book.
The real father of these lines, or at least the person who provided the original genetic material, was a linguist, mathematician, and computer scientist named Anthony Oettinger. Today, artificial intelligence and machine learning are white-hot topics, the sources of public fascination and billions of dollars in research and investment. But in the 1950s, when Oettinger began teaching at Harvard University, they were barely known. Oettinger was one of the pioneers in these fields—a multilingual polymath and one of the first people in the world to explore ways that computers could understand natural human language. The quest was, and still is, a challenge.
“Early claims that computers could translate languages were vastly exaggerated,” Oettinger wrote in a 1966 Scientific American article that predicted with eerie accuracy many of the later scientific uses of computers.2 The initial difficulty is that many phrases can have multiple meanings when they’re removed from a real-life context. The example he used was “Time flies like an arrow.” The sentence might mean that time moves with the swiftness of an arrow swooping through the sky. But as Oettinger explained, “time” could also be an imperative verb—a stern instruction to an insect-speed researcher “to take out his stopwatch and time flies with great dispatch, or like an arrow.” Or it could be describing a certain species of flying bug—time flies—that exhibit a fondness for arrows. He said programmers could get computers to try to understand the differences among these three meanings, but the underlying set of rules would create a new batch of problems. Those rules couldn’t account for syntactically similar but semantically different sentences such as—wait for it—“Fruit flies like a banana.” It was a conundrum.
Before long, the sentence “Time flies like an arrow” became a go-to example at conferences and in lectures to illustrate the challenges of machine learning. “The word ‘time’ here may be either a noun, an adjective, or a verb, yielding three different syntactical interpretations,” wrote Frederick Crosson, a University of Notre Dame professor and editor of one of the first artificial intelligence textbooks.3 The arrow-banana pairing endured and, years later, somehow became attached to Groucho Marx. But Yale librarian and quotation guru Fred Shapiro says, “There is no reason to believe that Groucho actually said this.”4
Yet the sturdiness of the line reveals something important. As Crosson points out, even in a five-word sentence, “time” can function as a noun, an adjective, or a verb. It is one of the most expansive and versatile words we have. “Time” can be a proper noun, as in “Greenwich Mean Time.” The noun form can also signify a discrete duration (“How much time is left in the second period?”), a specific moment (“What time does the bus to Narita arrive?”), an abstract notion (“Where did the time go?”), a general experience (“I’m having a good time”), a turn at doing something (“He rode the roller coaster only one time”), a historical period (“In Winston Churchill’s time . . .”), and more. In fact, according to Oxford University Press researchers, “time” is the most common noun in the English language.5
As a verb, it also has multiple meanings. We can time a race, which always involves a clock, or time an attack, which often does not. We can time, as in keeping time, when playing a musical instrument. And we, like dabbawalas and rowers, can time our actions with others. The word can function as an adjective, as in “time bomb,” “time zone,” and “time clock”—and “adverbs of time” represent an entire category of that part of speech.
But time pervades our language and colors our thought even more deeply. Most of the world’s languages mark verbs with time using tenses—especially past, present, and future—to convey meaning and reveal thinking. Nearly every phrase we utter is tinged with time. In some sense, we think in tenses. And that’s especially true when we think about ourselves.
Consider the past. It’s something we’re told not to dwell on, but research makes it clear that thinking in the past tense can lead to a greater understanding of ourselves. For instance, nostalgia—contemplating and sometimes aching for the past—was once considered a pathology, an impairment that diverted us from current goals. Scholars of the seventeenth and eighteenth centuries thought it was a physical ailment—“a cerebral disease of essentially demonic cause” spurred by “the quite continuous vibration of animal spirits through [the] fibers of the middle brain.” Others believed nostalgia was caused by changes in atmospheric pressure or “an oversupply of black bile in the blood” or was perhaps an affliction unique to the Swiss. By the ninteenth century, those ideas were discarded, but the pathologizing of nostalgia was not. Scholars and physicians of that era believed it was a mental dysfunction, a psychiatric disorder connected to psychosis, compulsion, and Oedipal yearnings.6