Sunday March 17, 2013

Q: Try to estimate (or guesstimate) how much toilet paper the U.S. uses in the course of a year.

Is it a) enough to roll from coast to coast? b) enough to circle the globe? c) enough to reach the moon? d) enough to reach to the nearest star?

A: An odd question, to be sure, but just the type a job interviewer might pose to test how well you think outside the box.

"Guesstimating is fun," says Old Dominion physicist Lawrence Weinstein in his book "Guesstimation 2.0," who begins by noting that he sits on the commode about once a day and uses roughly 10 sheets of paper each time.

But with possible differences in disposal plumbing and with differences between the sexes, to be on the safe side he doubles his daily estimate to 20 sheets.

Now this would tally to about seven (days) times 20 (sheets) times 50 (weeks), or about 7,000 sheets per person per year.

Next multiplying this by 300 million Americans, that’s about 2 trillion sheets annually. Taking each sheet at about 4 inches, the total length of toilet paper used by all Americans is about 660 billion feet, or about 120 million miles per year.

So you should choose answer d) above, concludes Weinstein, distance enough to reach the nearest star, or the sun, although if we unroll it that far, the toilet paper will get very charred .

Q: How is the story of pole-vaulting as much about the pole as it is about the vaulter?

A: Sports material experts are well aware that the job of the pole is to absorb, store and transfer energy from and to the vaulter to help him or her jump as high as possible, reports Scientific American magazine. Historically, the first poles date back to 829 B.C., made of ash or hickory and so stiff that when the athletes planted their poles, most of their kinetic energy was lost. In effect, they had to climb the poles and thus didn’t get very high.

Not until the 1920s did vaulters adopt more bendable bamboo poles, permitting some energy transfer and a push upwards. The days of pole-climbing were over. Pole-vaulting had begun.

Today’s poles are made of fiberglass or carbon fiber and are light and bendable to facilitate faster runs and a better transfer of kinetic energy, propelling the athletes ever higher.

Since the beginning of the 20th century, Olympic vaulters have gone from about 10 feet in 1900, up to 15 feet by 1950 and around 20 feet today -- all of it paralleling the material evolution in pole-vaulting.

Q: If you don’t quite know how your body is doing, perhaps a few body monitors are in order. To measure what?

A: Strap on a body monitor or two and let empirical data inform your most critical lifestyle choices, suggests Nathan Hurst in Wired magazine.

Accelerometers can record footsteps and sleep-time restlessness, GPS will track your location, altimeters will follow any changes in elevation -- all with built-in digitizing showing snapshots of data at a glance.

Though no two devices report exactly the same nuggets of data, they target exercise and health metrics, nudging you to become more active and to set goals.

You can even search out a specific workout session or track 24-hour totals.

For example, BodyMedia FIT LINK is an FDA-certified armband to help weight-watchers monitor movement, skin temperature, perspiration levels and more, providing a 95 percent accurate reading of caloric burn.

Motorola Motoactv not only counts your daily steps and calories burned but acts as a powerhouse partner for workouts such as running, cycling and using an elliptical. Upload a playlist and the monitor will track which songs get you to work out the hardest.