Are Lobsters Ambidextrous? (20 page)

 

Our body temperature is lowest in the early morning hours and highest in the evening. During deep NREM and REM sleep, we lose our ability to effectively regulate body temperature, so if the outside temperature is too warm or too cold, we must arouse somewhat in order to regulate our body temperature more effectively. During sleep we are not unconscious, so signals are able to get through to arouse us when needed, much as when we awaken from sleep when we need to go to the bathroom.

 

Submitted by Mark Gilbey of Palo Alto, California. Thanks also to Neal Riemer of Oakland, California
.

 

Why
do we feel drowsy after a big meal?

Eating, unlike heat, does directly affect our sleepiness quotient. After we eat a big meal, the blood supply concentrates around the digestive organs and intestinal system, reducing the blood supply for other activities. We tend to slow down metabolically and in our ambitions. (“Sure, why not have a fourteenth cup of coffee? They won’t miss us at the office.”)

Equally important, during digestion, foods are broken down into many chemicals, including amino acids such as l-tryptophan, which help induce sleep. Serotonins, which constrict the blood vessels, also make us drowsy. Alcohol, too, often produces
sleepiness—which may be another reason why so many business lunches end up with fourteen cups of caffeine-loaded coffee.

 

Submitted by David O’Connor of Willoughby, Ohio. Thanks also to Chaundra L. Carroll of Hialeah, Florida
.

 

What’s
the difference between jams, jellies, preserves, marmalades, and conserves?

All of these products started as a way to preserve fresh fruit (although they are now used primarily to provide a semblance of flavor on tasteless bread). The preparation of each involves adding sugar or other sweeteners (including other fruit juices) to the fruit to insure flavor preservation, and the removal of water to increase the intensity of taste. And most include additional ingredients found naturally in fruit: citric acid, to impart tartness; and pectin, a natural jelling agent.

The main difference among these foods is texture. Jellies are prepared from strained fruit juices and have a smooth consistency. Jams are made from crushed fruit (conserves, a type of jam, are made from two or more fruits, and often include nuts or raisins). Preserves use whole fruit or pieces of whole fruit. Marmalades use citrus fruit only and include pieces of the peel.

Fruit syrups and toppings, the type used in ice cream parlors, are prepared with the same cooking methods as other pre
serves. They are usually made from juices or purees of fruit and often contain corn syrup as well as sugar, to provide the runny consistency that insures the topping will topple off even a flattop ice cream scoop.

 

Submitted by Pamela Gibson of Kendall Park, New Jersey. Thanks also to Dana Pillsbury, parts unknown (please write with new address); Rich Dewitt of Erie, Pennsylvania; Jeffrey Bradford of Berkeley, California; and Elmo Jones of Burbank, California
.

 

Why
don’t trees on a slope grow perpendicular to the ground as they do on a level surface?

Trees don’t give a darn if they’re planted on a steep hill in San Francisco or a level field in Kansas. Either way, they’ll still try to reach up toward the sky and seek as much light as possible.

Botanist Bruce Kershner told
Imponderables
that

 

this strong growth preference is based on the most important of motivations: survival. Scientifically, this is called “phototropism,” or the growth of living cells toward the greatest source of light. Light provides trees with the energy and food that enable them to grow in the first place.

There is also another tropism (involuntary movement toward or away from a stimulus) at work—
geotropism
—the movement away from the pull of gravity (roots, unlike the rest of the tree, grow
toward
the gravitational pull). Even on a hill slope, the pull of gravity is directly down, and the greatest source of average light is directly up. In a forest, the source of light is only up.

There are cases where a tree might not grow directly up. First, there are some trees whose trunks grow outward naturally, but whose tops still tend to point upward. Second, trees growing against an overhanging cliff will grow outward on an angle toward the greatest concentration of light (much like a house plant grows toward the window). Third, it is reported that in a few places on
earth with natural geomagnetic distortions (e.g., Oregon Vortex, Gold Hill, Oregon), the trees grow in a contorted fashion. The gravitational force is abnormal but the light source is the same.

 

John A. Pitcher, of the Hardwood Research Council, adds that trees have developed adaptive mechanisms to react to the sometimes conflicting demands of phototropism and geotropism:

 

Trees compensate for the pull of gravity and the slope of the ground by forming a special kind of reaction wood. On a slope, conifer trees grow faster on the downhill side, producing compression wood, so named because the wood is pushing the trunk bole uphill to keep it straight. Hardwoods grow faster on the uphill side, forming tension wood that pulls the trunk uphill to keep it straight.

Why softwoods develop compression wood and hardwoods develop tension wood is one of the unsolved mysteries of the plant world.

 

We’ll leave that unsolved mystery to Robert Stack.

 

Submitted by Marvin Shapiro of Teaneck, New Jersey. Thanks also to Herbert Kraut of Forest Hills, New York; and Gregory Laugle of Huber Heights, Ohio
.

 

On
nutrition labels, why does the total number of grams of fat often far exceed the sum of saturated and polyunsaturated fats?

Foraging through our kitchen cabinet, we lit upon a box of Nabisco Wheat Thins. A consultation with the nutritional panel-yielded the following information about the fat content of a half-ounce serving:

And a look at the label on a Stouffer’s Lean Cuisine Oriental Beef with Vegetables and Rice Entree wasn’t much more enlightening:

We may not have been math whizzes, but even we know that two plus less than one does not equal nine.

What’s going on? Sally Jones, food technologist at the USDA’s food labeling division, told us that our arithmetic was impeccable but our nutritional IQ was in the dumper. We forgot that there is a third type of fat, monounsaturated, which can often, such as in the case of the Lean Cuisine entree, constitute more than half of a product’s fat.

Current labeling laws make it optional whether manufacturers list the grams of monounsaturated fat, often affectionately known as the “good fat.” The government doesn’t insist on listing monounsaturated levels, since there is some evidence that monos are actually good for us, fighting to raise our levels of HDLs, the “good cholesterol.”

When the giant upheaval of American food labels takes place, supposedly in 1993, but presumably later, food manufacturers will only be required to list their products’ percentage of saturated fat (i.e., the “bad fat”), the culprit that most consumers are trying to find out about when they consult the nutritional panel in the first place.

 

Submitted by Solomon Marmor of Portland, Oregon
.

 

Why
do ambulances have the emblem of a snake wrapped around a pole painted on them?

For as long as there have been ambulances, manufacturers have sought a symbol so that citizens could recognize the vehicle as an ambulance, even without the wail of the siren. As far back as the nineteenth century, the cross was the most frequently used symbol on ambulances around the world, but it never proved satisfactory, for two reasons. The cross was on the national flags of many countries, causing needless confusion, and the Red Cross Society screamed, pardon the pun, bloody murder whenever the cross was used on anything but military or Red Cross vehicles.

When the National Highway Traffic Safety Administration and the General Services Administration developed new federal specifications for ambulances in 1974, they decided that a new symbol specifically designating an ambulance was needed. The result: two new symbols were affixed to the exteriors of ambu
lances—a six-barred cross and the emblem in question, the “staff of Aesculapius.” Aesculapius was the son of Apollo and, in both Roman and Greek mythology, the god of medicine and healing; the snake was Aesculapius’s seal.

According to W. J. Buck Bension, national accounts manager for Southern Ambulance Builders, the staff of Aesculapius is a registered trademark of the NHTSA, designated for use only by and for ambulances and emergency medical personnel. But individual ambulance companies are free not to emblazon their vehicles with the staff of Aesculapius if they choose—if they want to risk incurring the wrath of the gods, that is.

 

Submitted by Gabe Miller of Ann Arbor, Michigan
.

 

What’s
the difference between “super” and ordinary glues?

The main difference between “super” glues and merely mortal ones is that Super and Krazy glues are fabricated from a manmade polymer called “cyanoacrylate,” while most other glues are a combination of natural resins in a solvent solution.

The different ingredients create a different bonding process, too, as Rich Palin, technical adviser to Loctite Corporation, reveals:

 

Most adhesives rely on mechanical fastening, meaning they penetrate into the tiny holes and irregularities of the substrate and harden there. Super Glue, on the other hand, creates a polar bond. The adhesive and substrate are attracted to one another like two magnets. Mechanical fastening also occurs with Super Glue, increasing the bond strength.

 

Borden Glue’s John Anderson adds that because super glues don’t rely solely on mechanical fastening, they are such better at bonding dissimilar surfaces than conventional glues. Thus, with super glues, the consumer is now able to accomplish many
everyday tasks for which regular glue is frustratingly inadequate, such as applying glue to the top of a hardhat so that one can stick to steel girders without any other means of support.