EDITOR’S NOTE: Liz Peek is a financial columnist.

Where would we be today if Galileo had encountered pitches for Lipitor while studying the celestial bodies? What if Sir Isaac Newton had been text messaging while he lunched under the apple tree? Might he have missed the apple ricocheting off his noggin? And Shakespeare — while booting up his computer, would Othello have been bumped from his head by pop-ups promising to inflate his, um, credit score?

These are serious questions, which will resonate with anyone who longs for downtime. I don’t mean time to respond to overdue emails or to catch up with the latest installment of your favorite TV series — I mean real idle time when your mind can veer off its track and bump around in random fashion. Downtime, that is, without intrusions from Blackberries, cell phones and especially without the clutter delivered to us by Diana Derval.

Ms. Derval is an advertising guru and author of Wait Marketing. Her book advocates the practice of assaulting consumers when they least expect it. (That’s not quite how she phrases it.) It is the rationale, for example, for the newly instituted TV screens in New York taxis. These days when you get into a Manhattan cab — Boom! — out of nowhere there’s a video practically in your lap blasting out the news of the day. (The volume is set on “invasive.”) It’s almost impossible to turn off, and by the time you do, your senses are rattled and whatever leisurely thoughts were puddling in your brain are long gone.

Ms. Derval’s brilliant contribution to our society is to encourage advertisers to extinguish all empty moments. Marketers of consumer goods like cosmetics and cereals are frustrated by the wiliness of today’s shoppers, who use their TIVOs to circumnavigate TV ads, bypass the pop-ups on their web pages, and wouldn’t dream of reading a newspaper. Advertisers are desperate to get at them. The solution? Find their idle moments, and lie in wait.

That’s why, when you are queuing for a bus, or pacing in an airline lounge, or having an anxiety attack in your dentist’s office, you have now become a target. You are vulnerable to flyers, billboards, and screens, and may possibly encounter all three in addition to a pervasive soundtrack. Ms. Derval’s book provides charts and algorithms to prove what we all know — that most people will tune in if they have nothing better to do. They have also learned that consumers are unusually attentive at those moments, so they are likely to remember the message.

Is this a bad thing? I think so. This new intrusion into our lives comes at a terrible time. The prevalence of cell phones and Blackberries has already robbed us of other mental time-outs. People never take a leisurely walk these days; instead they progress from one spot to another simultaneously catching up on phone calls or text messages. It used to be that you could buzz out while riding the bus or standing in line at the DMV (where you really should try to lose consciousness), but these days people are watching their favorite sitcom on a two-inch screen or checking stock quotes on the screen strategically placed overhead.

Idle time is when most of us used to think big thoughts. Looking out the window, strolling through a park, sitting in the tub; these are wonderful times to let your mind wander.

Educators routinely encourage parents to allow their children some downtime in their busy days. “Don’t over-schedule your kids,” we are told with authority. The message is that children need idle time to reflect, to be bored, and, then, to create. Children with nothing to do make up games and stories. That’s when they develop the inventiveness that would lead the grown-up Bill Gates to dream up Microsoft or JK Rowling to create Harry Potter.

Adults are never allowed to be bored any more. Think what the world is missing.