## Ana Veciana-Suarez

### Time is relative: It ticks faster as you age

When my eldest son’s twin daughters turned 7 this fall, he made an observation that marked him as a man firmly ensconced in adulthood.

"I don’t know where the time’s gone," he told me. "It’s like they were just born yesterday."

They were, but he’s just now learning that time speeds up as you get older. This phenomenon is a byproduct of the implacable calendar, like creaky joints and failing eyesight. Albert Einstein understood this decades ago, though his theory of relativity differs from mine. His is grounded in physics, mine in perception.

I’m not sure I can match his equation, either, though for the purpose of clarity I’ll give it a try: Birthday + 1 year = velocity of time squared.

Got that?

Let me explain it in a different format, in a way that will surely resonate among my peers. The older I get, the greater the sense of urgency. The urgency to spend more time with loved ones, the urgency to write better, the urgency to visit faraway places, the urgency to learn more, do more, enjoy more. Middle age, particularly late middle age, is a track and field event — not the marathon, mind you, but the 50-yard dash. As time ticks down on the stopwatch of life and ability, I’m sprinting against a loyal rival: mortality.

Wasn’t always so, this rush to — or against — the inevitable. When I was a child, some days dragged on forever. At 7, the age my oldest granddaughters are now, the mythical eighth birthday seemed a lifetime away. Summers lasted longer, as did vacations.

High school moved a little quicker, and thank goodness for that. (Awkwardness and self-absorption can be a dangerous mix.) Then college, especially the fun part, was over in a flash, four years gone so swiftly that I wish I had demanded a do-over at graduation. Now that I’m galloping through my 50s, the big Six-Oh blinks a warning: Hurry! Hurry!

There’s a reason age skews our assessment of time. Neuroscientist David Eagleman believes that the way we sense time varies according to how much new information we are processing. As children we take in plenty, which elongates how we perceive the passage of minutes. But as we get older, we face more and more familiar information and this information takes a shortcut through our brain. He calls time “this rubbery thing.’’ And indeed it is, in more ways than you might imagine.

Just the other day, I heard a National Public Radio story about a super-precise clock at the University of Colorado at Boulder. Though it’s able to measure the teeniest fractions of a second, timekeepers still face a conundrum. Because, the pace of time depends on gravity, as Einstein formulated, this very sensitive clock would tick faster on Mount Everest than at the bottom of the ocean.

This goes a long way in explaining why the number of birthdays influences our perception of time. As we age, as we climb the longevity graph ever upward, I like to think that we draw closer to the heavens, where the air is thin and gravity weak. Where few clouds block the horizon. At that altitude we realize we’re in a race against time, hustling to do what we want, what we’ve always been meant to do.

Can anyone prove otherwise?