Q: What just might be the most “extreme” human activity?
A: Astronauts in action would probably make the list, as would fighter pilots, free-fall parachutists, Formula One racing drivers and Acapulco cliff divers, says University of Cambridge mathematician John D. Barrow in “Mathletics: A Scientist Explains 100 Amazing Things About the World of Sports.”
But the activity that gets Barrow’s vote is drag-car racing. Apt to be found now only on tracks at disused airfields or salt flats in the middle of nowhere, these cars are like rockets with wheels, able to traverse a quarter mile (400 meters) in 4.5 seconds from a stationary start. Do the math; that’s faster than a NASA rocket launch.
“If a Formula One racing car were to pass the start at top speed when the drag car starts from stationary, it would still be beaten to the finish by the dragster,” Barrow writes.
That measures 6g of acceleration — six times gravity — and greater than 6g during deceleration after parachutes are released to slow the car. So extreme is this that detached retinas are “a serious problem for competitors. The noise levels also are dangerous for spectators, technicians and drivers. Good ear protection is absolutely essential.”
Q. What’s distinctive about the pair of numbers 220 and 284? Clue: You and your pals have a similar relationship.
A. They’re the smallest pair of “amicable numbers,” where each is the sum of the proper divisors of the other, explains Clifford A. Pickover in “The Math Book.”
The number 220 is evenly divisible by 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, which sum to 284.
The number 284 is evenly divisible by 1, 2, 4, 71 and 142, which sum to 220.
Such numbers are quite difficult to find, but in every known case, the paired numbers are either both even or both odd.
Interestingly, Genesis 32:14 records that Jacob gave 220 goats as a present to his brother Esau. “According to the mystics, this was a ‘hidden secret arrangement’ because 220 is one of a pair of amicable numbers, and Jacob sought to secure friendship with Esau,” Pickover writes.
Q. How have computers and computer games affected our nightly dream lives?
A. Studies have suggested even a few hours of television a day can change the nature of our dreams, says David Robson in New Scientist.
Dream researchers have been struck by how frequently subjects would report that their dreams were like movies in black and white — probably reflecting the commonplace viewing of television.
“Now just imagine what our intense relationships with computers are doing,” Robson poses. For example, Eva Murzyn of the University of Derby in the United Kingdom has found that people who play the “World of Warcraft” online tend to incorporate the game into their “midnight adventures.”
When Jayne Gackenbach at Grant MacEwan University in Edmonton, Canada, took a look, she found that players are beginning to report greater dream control, as if they are “active participants inside a virtual reality.” They are now more apt to fight back against dream enemies, feeling less scared than excited and offering comments like, “This was a nightmare, but it was awesome.”
Q: If you don’t quite know how your body is doing, perhaps a few body monitors can help. 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.
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 data, they target exercise and health metrics, nudging you to become more active and to set goals.
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.
Says Hurst: “Upload a playlist and the monitor will track which songs get you to work out hardest.” (Lady Gaga? Who knew?)