Doron Weber, a vice president at the Alfred P. Sloan Foundation and author of “Immortal Bird,” is writing a book about science and art.

Alan Burdick’s fascinating and eclectic 10-year odyssey in search of the meaning of time is “a mostly scientific investigation” that takes him from New York to Paris to the Arctic, from a 100-foot Zero Gravity Free Fall in Dallas to a claustrophobic MRI machine peering inside his brain, and from the writings of Aristotle, Augustine and William James to meetings with behavioral neuroscientists, cognitive psychologists and time researchers nationwide. It also takes him on a personal journey and a reckoning with himself, because time turns out to be the most intimate of topics, inherently subjective, despite Burdick’s best efforts to describe it objectively.

Reminding us that we have no direct receptor organ for apprehending time, such as our retina for light photons or our nose for scent molecules, Burdick sets out to understand what time really is and how we perceive it.

“Why did time seem to last longer when we were children? Does the experience of time really slow down when you’re in a car crash? How is it that I’m more productive when I have too much to do, whereas when I have all the time in the world, I seem to get nothing done? Is there a clock in us that counts the seconds, hours, days, like the clock in a computer?

"Why Time Flies: A Mostly Scientific Investigation," by Alan Burdick (Simon & Schuster )

Burdick ultimately is less concerned with external time — with the physics and math of cosmology — than with the biology, neuroscience and psychology of time. An award-winning science writer rather than a scientist, he feels emboldened by the current limits of scientific understanding. “If scientists agree on anything, it’s that nobody knows enough about time and that this lack of knowledge is surprising given how pervasive and integral time is to our lives.”

Burdick begins by demolishing the idea of one single, uniform and “true” time for the world. He visits the International Bureau of Weights and Measures near Paris where input from about 50 master atomic clocks representing 58 member nations is continuously processed, analyzed, compared and weighted to produce monthly a retrospective average world time known as Universal Coordinated Time (UCT). And UCT is a modification of International Atomic Time (IAT) based on a cesium atom that undergoes more than 9 billion quantum vibrations per second. When atomic clocks became the world standard in the 1960s, they revealed that the Earth’s 24-hour rotation is marginally slowing. This means that the length of each day is increasing by a second every few years and that “leap seconds” must be periodically added to IAT to sync it with the planet. Meanwhile, our cellphones and computer clocks in the United States are constantly receiving updated times from a dozen atomic clocks in two laboratories in Maryland and Colorado run by the National Institute of Standards and Technology, itself linked to GPS satellites synchronized to the U.S. Naval Observatory and its ensemble of 70 atomic clocks. Even ultraprecise American time is only a “fancy average.”

Arriving at Universal Coordinated Time for the world is a matter of consensus. “The world’s best time . . . is produced by a committee,” Burdick writes. “Time is what everyone agrees the time is.”

Having shown that official time is a social construction, Burdick demonstrates the deep biological roots of timekeeping that go back to microbes and the origin of life on Earth. The circadian clock, the 24-hour oscillation linked to the Earth’s diurnal rotation, is one of the most fundamental and ubiquitous cycles on the planet. This precise, molecular, timekeeping machine not only exists in each cell of our body — and in all animals, plants and fungi — but it manifests in the most primitive life-forms, cyanobacteria, where three proteins keep time. These billion-year-old proteins tick independently of genes and DNA; even when they are removed from the cell and placed in a test tube, they continue ticking!

Nowhere is this dependence of life on synchronization with circadian rhythms more evident than in newborns. As exhibit A, Burdick cites the birth of his twin boys, Leo and Joshua, who will form a series of illustrative examples as they grow up. After an intimate acquaintance with time in the womb via dopamine and melatonin secreted by their mother — these neurochemicals “play a critical role in syncing the fetus’s master clock to the external time of day” — birth jettisons Leo and Joshua into “temporal chaos,” leaving them temporarily clockless. No one in the house can sleep until the working circadian clock in the newborn’s hypothalamus has been synchronized with the rest of the infant’s brain and body and entrained to the local environment, especially to sunlight.

Learning about time takes time, as Burdick and his wife, Susan, discover during a sleepless year.

If an inadequate sense of time can impair, too much temporal pressure can oppress. Trying to shed his own ticking internal clock, Burdick, now a father of two toddlers with a book contract, lights out for Toolik Field Station in the Arctic, 125 miles north of Fairbanks, Alaska. “What does biological time look like at its most bare?” he asks as he trudges through a landscape of permafrost tundra during polar summer and eats in a perpetually open mess hall. There are no sunsets in these extreme conditions and Burdick’s circadian rhythm becomes confused as the days flow into one another and 24 hours, or any hours, loses meaning. He experiences timelessness but also misses his kids’ birthdays.

Burdick’s chief guide and touchstone on this journey is Augustine and his “strange and riveting” “Confessions,” often considered the first autobiography (which Burdick interestingly regards as “a memoir of evasion”). Augustine saw time as “a window onto the soul” but his introspective approach “plucked time from the realm of physics and placed it squarely in what we now call psychology.” His ideas would not only inform centuries of philosophers but lead to today’s primary concern with time as an internal experience, “a property of the mind.”

For Augustine, past, present and future don’t exist except in the mind, and we can be sure only of the present. Or rather it is only our perception of the present we can be sure of, and even then, only as it passes, because once it has passed, “it will not exist to be measured.” How long or short is now and how many mental items can you hold in it? William James argued that the present was something we stumble into, “a synthetic datum” that is a form of consciousness, and Burdick visits the labs of various researchers who try to identify “the smallest possible moment of direct human awareness.” He identifies two concepts: the fleeting “perceptual moment” as short as one-twentieth of a second; and the “psychological moment,” a longer period of several seconds when a single event unfolds. Studies of how fast off the huddle the 1920s Stanford football team could move showed they were one-tenth of a second slower if they didn’t know the count, suggesting that’s how long it took to think. Later instruments detected neural impulses that could travel at 400 feet per second, or 250 miles per hour. Burdick shows how scientists have been creating ever-tinier windows of time to study the world of matter, recently breaking the “femtosecond barrier” with a superfast pulse of laser light that could capture an electron decaying.

After traveling halfway across the world, reviewing millennia of philosophy and a century of science and speaking to countless time researchers in countless labs, Burdick admits he has not succeeded in solving the ultimate mystery of time. He worries that “timing research runs the risk of spreading itself too thin” and he hankers for an “overarching scheme that will bring order and consistency to a sprawling field.”

But as his narrative draws to a close and Burdick turns inward, revealing more about his life with his children, his wife, his aging parents and his father in law — as well as more about his personal history, his struggles as a writer and his complex relationship with the past — we grasp that this has been a voyage through Burdick’s life as a man, husband, father, son, writer and mortal human. In this sense, “Why Time Flies” evokes another far-ranging, symbolic odyssey with an everyman protagonist, that modernist conversion of Homer’s 3,000-year-old, decade-long epic into James Joyce’s “Ulysses.”

“Every life is many days, day after day. We walk through ourselves, meeting robbers, ghosts, giants, old men, young men, wives, widows, brothers-in-law. But always meeting ourselves,” Joyce wrote.

We never get a full-on portrait of Burdick, more of a tantalizing silhouette, but it’s enough to make us realize that this mostly scientific journey through the world of time is also a voyage of self-discovery and finding one’s way back home.

Of time and the human, Burdick sings.

Why Time Flies
A Mostly Scientific Investigation

By Alan Burdick

Simon & Schuster. 299 pp. $28