Smoking or non-smoking?
This could have been a question we received from a maître d’ at a European restaurant.
But it wasn’t. The year was 1999, and my parents and I were checking into our flight from Istanbul to Paris on Turkish Airlines.
Smoking or non-smoking?
My parents picked the non-smoking section. Wise choice, I thought.
But then two things revealed themselves in rapid succession. First, smoke doesn’t remain stationary. It moves. Second, smoke moves particularly fast on an airplane designed to create a continuous circulation of air.
Looking back, this seems ridiculous. How did we possibly think it was a good idea to allow smoking on flights—as recently as 20 years ago? Setting aside the immense amount of secondhand smoke imposed on the residents of the non-smoking section, an in-flight fire started by someone lighting up a cigarette could be unhealthy for everyone on board.
But let’s go back further.
In the early 20th century, doctors and dentists were some of big tobacco’s biggest salesmen, endorsing cigarette smoking to help with digestion, physical fitness, and stress. This link, which shows vintage ads of doctors endorsing tobacco, is well worth the look. “Leading nose and throat specialists suggest Phillip Morris,” reads one ad. “More doctors smoke Camels than any other cigarette!” reads the other (take that, Trident!).
Many of today’s controlled substances were once common household items. As Ayelet Waldman writes, “[U]p through the twentieth century, opioids and cocaine were readily available and used. The Sears Roebuck catalog, the amazon.com of the time, featured kits with syringes and vials of heroin or cocaine, complete with handy-dandy carrying cases… In fact, it wasn’t until 1929 that Coca-Cola became free of [cocaine], thereafter relying solely on caffeine to invigorate its customers. Bayer Pharmaceutical ads from the period advertise both aspirin and heroin.”
I could go on. Doctors didn’t believe infections could kill women in the maternity ward, so they didn’t bother to wash their hands before delivering a baby. Salt and saturated fat were thought to be deadly, but new studies call these findings into question. Lead, which can cause serious health problems, was commonly used in paint, gas, and plumbing.
“Nothing in the physical world seems to be constant or permanent,” the physicist Alan Lightman writes. “Stars burn out. Atoms disintegrate. Species evolve. Motion is relative.”
The same is true for facts. All facts have a half life. What is advised with confidence this year can be reversed the next. The history of science, as Chris Kresser says, “is the history of most scientists being wrong about most things most of the time.” Aristotle’s ideas were falsified by Galileo’s, whose ideas were replaced by Newton’s, whose ideas were modified by Einstein. And Einstein’s own theory of relativity broke down at the subatomic level.
We were certain about each of these facts—until we were not.
Some see this as a reason to distrust science. I see it as a reason to embrace it.
“One mark of a great mind,” as Walter Isaacson puts it, “is the willingness to change it.” When the world around you changes—the tech bubble bursts or self-driving cars become the norm—the ability to change with the world confers an extraordinary advantage.
The question isn’t whether facts change (they do—all the time).
The question is this: Is your mind nimble enough to keep pace when the facts change?