The University of California, Berkeley announcement of the potassium discovery presents the current consensus:
The Earth is thought to have formed from the collision of many rocky asteroids, perhaps hundreds of kilometers in diameter, in the early solar system. As the proto-Earth gradually bulked up, continuing asteroid collisions and gravitational collapse kept the planet molten. Heavier elements—in particular iron—would have sunk to the core in 10 to 100 million years’ time, carrying with it other elements that bind to iron.
Gradually however, the Earth would have cooled off and become a dead rocky globe with a cold iron ball at the core if not for the continued release of heat by the decay of radioactive elements like potassium-40, uranium-238 and thorium-232, which have half-lives of 1.25 billion, 4 billion, and 14 billion years, respectively. About one in every thousand potassium atoms is radioactive.
As you have seen, scientists tend to take the long view. Although San Francisco biophysicist Joe Doyle later reiterated the “radioactive theory,” his first response to why the center of the Earth is still hot was:
There hasn’t been enough time for it to cool yet.
Submitted by Lance Burpee of Lisbon Falls, Maine. Thanks also to Peter Gosling of Ann Arbor, Michigan; and Charles Scourfield of Moss Vale, New South Wales, Australia.
Why Do More Men Snore Than Women?
“Laugh and the world laughs with you. Snore and you snore alone.”
No doubt about it. The delicate issue of snoring has caused fussin’ and feudin’ in more than a few relationships. Abigail “Dear Abby” Van Buren published a letter from “Frantic in Fresno,” a woman who was married for fifteen years to a man whose snoring woke her up “wondering who was mowing the lawn,” and who complained about having nightmares in which “a tugboat was stuck in the bedroom.” The husband wouldn’t allow Frantic to sleep in another bedroom, and wouldn’t seek medical help for his condition, which, come to think of it, didn’t keep him up nights.
Abby asked her readers for their comments, and received more than 5,000 replies. More than 90 percent of the respondents reported that they slept apart from their snoring mates. Abby concluded that “love is blind, but not deaf,” adding that when women were confronted about snoring, they took it as an insult. In fact, their mates reported that most women wouldn’t admit to snoring.
It’s hard not to joke about snoring, but consider this: The loudest snore ever measured, 92 decibels, exceeds the United States’ Workman’s Compensation threshold for requiring ear protection on a worksite (90 decibels). By comparison, normal speech is approximately 40 decibels; normal city traffic, 65 decibels; a jet plane, 110 decibels; a jackhammer, 120 decibels; and the pain threshold (think of a heavy-metal rock concert), 140 decibels.
About one-half of adults snore occasionally, and about one-quarter regularly. The two most popular stereotypes about snoring happen to be true: Older folks, as we reported in Do Elephants Jump?, snore more than younger ones; and more men do snore than women. Almost twice as many men as women snore, but women start catching up as they pass middle age. About 55 percent of men over 60 snore, compared to 45 percent of women over 60.
What causes snoring? Bad vibrations. When we sleep, our respiration rate lowers, but we continue breathing. With luck, the air passageways between the nose and throat and our lungs remain clear while we are asleep. If so, we hear at most a few “zzzzzz’s.” But if there is an obstruction of any kind, the structures of the mouth (most commonly, the soft palate, tongue, tonsils, and uvula) strike against each other and vibrate, and we hear the starts and snorts of snoring.
The tongue and throat structures must be flexible so that we can create the different sounds necessary for our language, and so that we can destroy a sirloin steak and sip caramel lattes with the same apparatus. But if the air passageways from the throat down to the lungs were a stiff tube, it would serve us better for the purpose of breathing. When we sleep, our muscles relax. The muscles that help keep the air passageways in our throat open during the day tend to constrict even for nonsnorers. The soft sides of the throat pull inward, and they vibrate like a flag rippling on a windy day.
Most of the causes of snoring are not sex-specific. Anything that promotes diminution of the muscle tone in the throat can lead to snoring, which is one of the reasons why most of the sleep specialists we consulted recommend eliminating smoking, drinking, and unnecessary pharmaceuticals (especially antidepressants, antihistamines, and ironically, sleeping pills). Overuse of drugs and alcohol results in loss of muscle tone that promotes vibrations in the throat. Smoking can cause a thickening of throat tissues, shrinking the area through which air can pass freely. While there is evidence that men overindulge in all of these “vices” more than women, smoking seems to affect the level of snoring equally in both sexes.
The most common risk factor in snoring is obesity. Obese people tend to have fatty deposits located below the mucous membranes in the throat that block proper airflow. Dr. Mansoor Madani, director of the Center for Corrective Jaw Surgery, in Bala Cynwyd, Pennsylvania (http://www.snorenet.com), told Imponderables that many of his patients are overweight and developed snoring problems only after becoming so. Many patients report snoring disappearing after significant weight losses. Although more men than women are obese, as with the “vices” listed above, it is not enough to explain the huge disparity in snoring rates.
Snoring is one condition in which bigger is definitely not better. If snorers experience periods of total breath obstruction during sleep (usually in between snorts), the condition is known as “obstructive sleep apnea” (or OSA). The single greatest predictor of sleep apnea is neck size. If your neck size is seventeen inches or greater, you have a thirty percent chance of suffering from sleep apnea.
Obviously, many more men than women have large necks, and there is some evidence that the structures inside the throats of large people are disproportionately bulky. According to Dr. Sunny Dong, a sleep specialist in British Columbia:
Women tend to have a shorter pharynx, which is less likely to vibrate during sleep. The soft palate is often thinner and the uvula is smaller, which makes the vibrations less loud and the frequency higher (which tends to make it less annoying).
As we age, the muscle tone in our throat tends to decrease, which results in more vibrations and snoring when sleeping. The tongue enlarges with age, which intensifies the problem. But Dr. Madani reports that the skin texture is firmer in women. Men’s throat tissue gets “floppier” as they get older.
The big controversy among sleep disorder specialists is the role of hormones in snoring. Some of the experts we consulted feel that medical science still can’t explain the etiology of men’s higher snoring rate. Dr. Andy Blockmanis, of the Pacific Center for Sleep Disorders in Vancouver, British Columbia, speculates that men’s greater weight, on average, may account for the snoring “gap,” and that women’s increase in snoring as they age may be attributed to their tendency to gain weight after menopause.
Most of the experts we consulted do believe that hormones affect snoring rates. They point to the obvious clue that the gender gap in the snoring rate narrows drastically after women undergo menopause, when almost as many women as men snore.
Dr. Dong points specifically to the role of progesterone, a female steroid sex hormone:
Before menopause, women have much higher progesterone levels than men and this hormone increases the tone in the airway muscles and increases respiratory drive, both of which lessen the tendency of the pharynx to collapse and vibrate. After menopause, the progesterone levels drop and more women begin to snore.
Anecdotal evidence supports the case for hormonal differences as a major factor. Dr. Christian Guilleminault, cofounder of the journal SLEEP, feels that women are protected from snoring by progesterone and estrogens, and points out that when women are treated with testosterone, this protection often disappears.
David Nye, a physician at the Midelfort Clinic in Eau Claire, Wisconsin, not
es that androgens—male hormones—increase snoring. His partner, Donn Dexter, published a paper indicating that one female patient’s problems with sleep apnea were resolved after a testosterone-secreting tumor was removed in surgery.
Most of the treatments for snoring are not sex-specific. For some, eliminating vices such as smoking or drinking can solve the problems. Others find nasal sprays or air-flow masks helpful—more than 300 patents have been filed for snore-control devices. Many surgical procedures using knifes or lasers can alleviate snoring difficulties. Our favorite is “uvulopalatopharyngoplasty,” a procedure to reduce the size of the uvula, the soft palate, or both.
Why would someone go under the knife for uvulopalatopharyngoplasty for a problem as benign as snoring? Ask the significant other of the snorer. Several years ago, an Iranian man filed for divorce, accusing his wife of secretly drugging him so that he wouldn’t hear her snore. The wife admitted drugging her newlywed husband’s dinners; the husband caught on to her trick by skipping his usual evening meal one night. The wife of only forty days volunteered to sleep during the day and stay awake at night in order to save her marriage, but the reluctant groom rejected the proposal.
Submitted by Marlena Lynch of Fort Worth, Texas. Thanks also to Neil Young of Mill Valley, California.
Why Do Vultures “Waste Time” by Circling Their Dead Prey Instead of Swooping In and Chowing Down Immediately?
We’ll give you the executive summary first. When a vulture circles before eating, there are probably one or two reasons for the behavior—it is checking to make sure that the prey is actually dead or it is looking for other possible predators, especially land predators that might serve as competitors for the food. Vultures are eaters, not fighters, and neither want to kill a potential food source nor fight four-legged or winged competition for a meal.
But the executive summary leaves out a lot of fascinating information about vultures and the most shocking surprise ending since Psycho. There are three different species of vultures found in North America. The turkey vulture (mistakenly called buzzards by many) is by far the most common, found in all fifty of the United States, Canada, and Mexico. The black vulture generally is found only in the southeastern United States, and the California condor (despite the fancy name, it’s really a vulture), nearly extinct just decades ago, can be found in the wild not only in California, but also in Arizona and Baja California, Mexico. Unless otherwise specified, we’re talking primarily about the turkey vulture in this discussion.
One of the big differences between turkey vultures and their two relatives is that the turkey vulture has a strong sense of smell along with excellent vision. Another difference is that turkey vultures tend to fly lower than the other two species. These two distinguishing characteristics are likely not a coincidence, as one of the ways in which the vulture identifies its prey as dead is by smelling mercaptan, a gas emitted by decomposing carrion. The very smell that disgusts us is like the aroma of freshly baked chocolate-chip cookies to them. Ornithologists have tested vultures’ sense of smell by hiding carrion; the vulture can find the dead animal just from the odor.
Vultures may be scavengers, but they do have strong preferences in food. They choose to eat herbivorous animals, such as cows and deer, over meat-eaters like dogs, cats, and coyotes, although if hungry enough, they’ll settle for the less tasty carrion. They also have a strong preference for freshly killed meat over decomposed carrion, but because their beaks are relatively weak, they have problems penetrating the hides of animals. Black vultures and California condors have stronger beaks, and they occasionally “share” a meal of carrion that the turkey vulture could not polish off alone (it is far more likely, though, that the black vulture and condor will chase the turkey vulture off the prize, without so much as a finder’s fee as recompense). More often, the turkey vulture bides its time until it can devour the carrion itself.
Ready for the surprise ending? Most of the experts we consulted did not agree with the premise of the question. One turkey vulture expert, who prefers to remain anonymous, rather angrily pointed us to the FAQ (frequently asked questions) section of the Turkey Vulture Society’s Web site, which clearly states: “Contrary to popular belief, vultures do not circle over dead or dying animals.”
How can we account for the “myth,” then? To conserve energy, vultures flap their wings as little as possible. They can soar for great distances and long periods of time by taking advantage of thermals—updrafts of rising, warm air. Because of the birds’ less than sterling reputation, human bystanders might assume that the vultures are circling prey, but turkey vultures often circle together in thermals just to gain altitude—if they catch the drafts properly, they can soar for hours without flapping their wings.
Black vultures are much more social than turkey vultures. When they encounter large carrion, they often fly above the prey to attract fellow vultures to help polish off the carcass—the behavior isn’t necessarily altruistic, as there is safety in numbers. The black vultures are well placed to see turkey vultures below them, and can pick off a discovery from a turkey vulture. One turkey vulture has a good chance to fend off a single black vulture, but not a flock of them.
Whether we call it soaring, circling, or hovering, the vulture is careful to make sure its prey is dead before hitting the ground, and careful to look for competition from other birds and animals. But all experts agree on one thing—once the vulture thinks that all signals are go, it doesn’t dilly-dally: it swoops in quickly and chows down!
Although vultures may have many competitors for food, they have few natural predators, which is lucky for them, for they have few weapons in battle. Their best shot at deterring enemies is a direct result of their less than appetizing diet, as Sy Montgomery, in his article, “Heavenly Scavengers” in Animals magazine, explains:
wild vultures have habits some people find, well, unsettling. Their method of self-defense, for example, is to vomit their food, which they can send sailing 10 feet. Remember that turkey vultures eat nothing but carrion, and the odor does not improve from the sojourn in the vulture’s stomach.
The other end of vultures can be hazardous, too. Their white legs only look white; it’s really “whitewash” from the material they defecate on their legs. [The waste matter contains acids that help kill bacteria from the carrion that results from the vulture’s legs coming in contact with the decomposing carrion.]
Though these behaviors might distress people, they serve turkey vultures well. Vulture vomit is an effective predator repellent, as researchers who have worked with the species can attest.
Submitted by Susan Friend-Trommatter of Surry, Virginia.
What’s the Purpose of the “SysRq” Key on Most Computer Keyboards?
The “SysRq” key, short for “System Request,” is one of those features added by computer geeks to let us average users know that we are but mere interlopers in their world. The good news is that pressing the SysRq key (sometimes labeled “Sys Req”) by mistake is unlikely to do any damage to your computer session. The bad news is that pressing the SysRq key is unlikely to do anything at all.
On most PC keyboards, the SysRq key shares a key with the Print Screen command, which has the virtue of actually doing something (creating screen shots of what you see on your monitor), but usually only if preceded by pressing Ctrl + Alt. In other words, if you are word processing and mistakenly hit the Print Screen/SysRq key, nothing seems to happen (in some systems, hitting Print Screen will make a copy of the screen on your clipboard).
At one time, IBM had great hopes for the now obscure SysRq key. It appeared as a function key on the keyboards used to control IBM’s popular 3270 terminals (designed to interact with IBM’s mainframe computers). SysRq allowed users to directly communicate with the underlying operating system to, say, switch sessions on the host server. Circumstantial evidence indicates that IBM had the same role in mind for the key for personal computers, as SysRq did not appear on the 83-key PC/XT keyboard but became the 84
th key on the AT keyboard (designed to work with Intel’s then-snazzy 286 processor) in 1984. But most programs never took any advantage of the opportunity to develop this “attention” key.
SysRq is making a bit of a comeback, though, as the free and open-source operating system, Linux, offers users a “magic SysRq key.” Once this feature is enabled, by pressing Alt + SysRq, users can communicate directly with the underlying operating system. Once invoked, the magic SysRq key can do things like reboot the system when it is unresponsive to the usual methods or dump current memory to your console, helpful when debugging.
Although keyboards now sport twenty more keys than they did when the AT keyboard was king, most popular programs seem to utilize fewer function keys than ever (when’s the last time you used the “Scroll Lock” key?). But excising a key from the computer keyboard, even if it usually lay untouched, is harder to accomplish than scrubbing a pork barrel project from the home district of a member of the House Appropriations Committee.
Submitted by Darrell Wong of Pearl City, Hawaii.
Why Do Taxicab Drivers Often Put Their Car in Park While Waiting at a Stoplight?
It’s probably not a coincidence that this question came from New York City; we’ve seen this curious behavior most often in big cities. Sometimes when we are confronted with a new Imponderable, we play a little game of Malarky, and try to come up with bluff answers. In this case, we could think of at least three cool alternatives:
Why Do Pirates Love Parrots? Page 17