Man bites dog: Dog gets worst of i


Q. Doggone it, does a dog or human have the stronger bite? –D.J. Bickers

A. Bite forces have been actively studied in a number of species, living and extinct, says Jerry D. Harris, director of paleontology of Dixie State College. Going by the data, an American alligator bites with a force of about 19000 Newtons (4300 pounds), a hyena about 9000, a lion 4200, a dusky shark 3000, and a Labrador retriever 1100 (250 pounds). Would you believe a person actually checks out higher than the retriever at 1500 Newtons (340 pounds)!

But these force values are for the entire mouth, based on jaw and teeth shape. So while a human beats out the Lab, says Harris, the dog has much pointier teeth distributed in a narrower mouth, making for a more concentrated chomp at the teeth tips. Thus, Duke can do far more damage, though human bites can be plenty nasty.

Q. Okay now, baseball slugger... Your girlfriend's coming to see you in action at the stadium, and you'd really like to impress her with your raw batsman's power. You're not into "corking" the lumber. What's an honest guy to do? –G. Triandos

A. You just might be a hit with her if you read up on "How to Hit Home Runs: Optimum Baseball Bat Swing Parameters for Maximum Range Trajectories," by Gregory Sawicki and Mont Hubbard (American Journal of Physics). You already know from Robert Adair's "Physics of Baseball" that a warm day in the thin air of a Denver will add feet to your clout. So too will an accommodating tailwind.

But these are pretty much beyond your control. Pumping iron and beefing up to add batspeed are clearly not. Increasing batspeed by just 1 meter per second increases the optimal range by nearly 5 meters (16 ft), says Sawicki. Aiming to undercut the ball is another trick, because this will add backspin and "lift" to the ball. For a typical fastball, undercutting it by 2.65 cm and swinging upward at a 10-degree angle will maximize distance.

Even better is to pick out a juicy curve ball. Surprisingly, because of beneficial topspin that is enhanced during the bat collision, a well-hit curve has more lift and travels farther than a well-hit fastball or knuckler, by maybe 4 meters (13 ft). And a faster curve (like a faster fastball) will go a little farther than a slower one.

So pick out the right pitch, aim to pull it down the line (Adair), and let 'er rip! And just hope the ball lands right in your girlfriend's glove.

Q. Know what it takes to become a famous "psychic" performer who stops the watches of people in the audience? –N. Renier

A. Cook up a spiel, get on TV, and announce the moment, describes Richard Dawkins in Unweaving the Rainbow. Here's the nub: Any timepiece has a certain stop-chance at any given moment– from a dead battery, etc.

So a good guess would be the average device stops once a year. But a clock stopping the next day won't help you. It must stop within, say, 5 minutes of your making the pitch. Figuring there are about 100,000 5-minute spans in a year, the chances of any particular clock stopping at a time helpful to you are about 1 in 100,000. Sounds bad, until you multiply this by a million viewers' clocks and watches.

Odds are good 5-10 of these will stop right on cue. Then if you add in ones that stopped hours or days ago but the owner just now notices, plus sudden "mysterious" heart attacks where the relatives call in, you'll do just fine.

Oh, and then there's Nobelist Richard Feynman's tale of how his first wife died at 9:22 and it was later noticed the clock in her room stopped at 9:22. Turns out the nurse on duty picked up the clock to record time of death, halting its ailing clockworks.

Q. A just-born baby comes packaged in vernix caseosa, Latin for "cheesy varnish." What is it and what does it do? –U.G. Turner

A. It's the milky colored slick substance that covers baby's skin, comprised of dead cells, oil from sebaceous glands, temporary downy hair, and traces of mom's chemical exposures, says Cynthia F. Bearer, M.D. pediatrician and neuroscientist at the Case Western Reserve University School of Medicine.

True, it acts as lubricant for baby's stage entrance but also serves to "waterproof" the fetus during the critical last trimester and to guard against microbes and other assaults. Though baby is cleaned up very soon after birth, care is often taken not to wash off all the coating, which just may be Baby's first line of defense against the dry and cool extrauterine environment.

So special is this stuff, says Dr. Bearer, that there's interest in bottling some of it as antibacterial unguent for whatever ails baby later, and it may one day even be used on adults. Just another of Mother Nature's medicinal marvels.

Send Strange questions to brothers Bill and Rich at