When Do Fish Sleep? Part 3

What should one do about floaters? An occasional spot is usually harmless, although sometimes floaters can be precursors of retinal damage. Most often, a home remedy will keep floaters from bothering you. The American Academy of Ophthalmology suggests: if a floater appears directly in your line of vision, the best thing to do is to move your eye around, which will cause the inside fluid to swirl and allow the floater to move out of the way. We are most accustomed to moving our eyes back and forth, but looking up and down will cause different currents within the eye and may be more effective in getting the floaters out of the way.

Although you may be aware of their presence, it is often surprisingly difficult to isolate floaters in your line of vision. Because the floaters are actually within the eye, they move as your eyes move and seem to dart away whenever you try to focus on looking at them directly.

Submitted by Gail Lee of Los Angeles, California.

Does It Ever Really Get Too Cold to Snow?

Having withstood a few snowy midwestern winters in our time, we're not sure we would want to test this hypothesis personally. Luckily, meteorologists have.

No, it never gets too cold to snow, but at extremely low temperatures the amount of snow acc.u.mulation on the ground is likely to be much lower than at 25 degrees Fahrenheit. According to Raymond E. Falconer, of the Atmospheric Sciences Research Center, SUNY at Albany, there is so little water vapor available at subzero temperatures that snow takes the shape of tiny ice crystals, which have little volume and do not form deep piles. But at warmer temperatures more water vapor is available, "so the crystals grow larger and form snowflakes, which are an agglomerate of ice crystals." The warmer the temperature is, the larger the snowflakes become.

What determines the size of the initial snow crystals? It depends upon the distribution of temperature and moisture from the ground up to the cloud base. If snow forming at a high level drops into much drier air below, the result may be no acc.u.mulation whatsoever. In the condition known as "virga," streaks of ice particles fall from the base of a cloud but evaporate completely before hitting the ground.

Submitted by Ronald C. Semone of Was.h.i.+ngton, D.C.

Why Do Dogs Have Black Lips?

You would prefer mauve, perhaps? Obviously dogs' lips have to be some color, and black makes more sense than most.

According to veterinarian Dr. Peter Ihrke, pigmentation helps protect animals against solar radiation damage. Because dogs don't have as much hair around their mouths as on most parts of their bodies, pigmentation plays a particularly important role in s.h.i.+elding dogs against the ravages of the sun.

According to Dr. Kathleen J. Kovacs, of the American Veterinary Medical a.s.sociation, the gene for black pigment is dominant over the genes for all other pigments, so the presence of black lips is attributable to hereditary factors. If two purebred dogs with black lips breed, one can predict with confidence that their puppies will have black lips too.

Not all dogs have black lips, though. Some breeds have nonpigmented lips and oral cavities. James D. Conroy, a veterinary pathologist affiliated with Mississippi State University, told Imponderables that some dogs have a piebald pattern of nonpigmented areas alternating with pigmented areas. The only breed with an unusual lip color is the Chow Chow, which has a blue color. Conroy says that "the blue appearance of the lips and oral cavity is related to the depth of the pigment cells within the oral tissue."

Submitted by Michael Barson of Brooklyn, New York.

If Church and State Are Supposed to be Separated in the United States, Why Do We Swear On Bibles in Courts? What Happens if a Witness Doesn't Accept the Validity of the Bible?

The ritual of taking an oath with the right hand raised while placing the left hand on a holy object goes back to ancient times. Michael De L. Landon, secretary of the American Society for Legal History, sent us a picture of the Bayeux Tapestry, which depicts King Harold of England, who reigned from 1035-1040, taking an oath with both hands on a sacred object.

In the Middle Ages, before printed Bibles were commonly available, Christians placed the left hand on a relic of a saint or some other sacred object and raised the right hand while taking an oath. Professor De L. Landon comments: the right hand raised and open, palm outward, is an internationally recognized gesture implying peace, honesty, and good intentions. In taking an oath, there is also probably the indication that one is pointing to heaven and calling upon G.o.d (or the G.o.ds) to be one's witness that one is sincere and telling the truth.

The English adopted the practice of having witnesses swear an oath on the bible before testifying. American law was based originally on an English common law that stipulated that only witnesses who believed in a Supreme Being could testify at a trial. The framers of the common law a.s.sumed that only the fear of an eternal punishment would ensure the honesty of the witness. Lord c.o.ke, the leading English jurist of the early seventeenth century, went further and argued that nonconformists as well as atheists were petui inimici ("eternal enemies") and should be barred from testifying. c.o.ke's position was adopted by the English for almost two hundred years, and although it became impossible to enforce the doctrine, Parliament did not actually remove the statute until 1869.

Most courtrooms have stopped using Bibles to swear in witnesses, for the ritual was always a ceremonial demonstration of good faith rather than a legally mandated procedure. Most courts traditionally have used King James Bibles, but have allowed Jews or Catholics to subst.i.tute versions that were acceptable to their faith.

The United States adopted the rule disqualifying disbelievers in the Federal Judiciary Act of 1789, which provided that no one could testify "who did not believe that there is a G.o.d who rewards truth and avenges falsehood." In 1906 Congress pa.s.sed an amendment to allow states to determine their own rules for their own courts, although most states had already pa.s.sed statutes voiding the disbeliever clause. Even today, a few states have not struck down the disbeliever clause; theoretically, an atheist could be barred from testifying in a trial in those states.

In his book Church, State and Freedom, Leo Pfeffer notes broader const.i.tutional provisions ensure that no civil rights may be denied because of religious beliefs. Still, the issue hasn't been addressed squarely by the Supreme Court, and Pfeffer doc.u.ments a scary application of how the nonbeliever clause has been applied in the past: in 1900 the Court upheld a Federal statute that required that the testimony of Chinese, in certain cases, be corroborated by that of white men, because of the 'loose notions entertained by [Chinese] witnesses of the obligation of an oath.' It would seem clear that if a defendant in a criminal case or a party in a civil case could not take the stand in his own behalf because of his religious beliefs or disbeliefs, he would be deprived of his liberty or property without due process of law and would be denied the equal protection of the laws in violation of the Fourteenth Amendment. Moreover...the 'free exercise' clause of the First Amendment protects religious disbelief as well as belief...

As might be expected, both the ACLU and Madalyn Murray-O'Hair's Society of Separationists have been in the forefront of litigation attempting to eliminate swearing on Bibles (as well as eliminating other elements of religion in the courts). The path of least resistance, for most jurisdictions, has been to abandon the use of Bibles.

One need not be philosophically opposed to the use of Bibles in the courtroom to note that a Bible has never been a guarantee of truthful testimony; perjurers have been swearing on Bibles for a long, long time.

Why Do Females Tend to Throw "Like a Girl"?

Not only do girls (and later, women) tend not to be able to throw b.a.l.l.s as far as boys, but their form is noticeably different. If you ask the average boy to throw a baseball as far as he can, he will lift his elbow and wind his arm far back. A girl will tend to keep her elbow static and push forward with her hand in a motion not unlike that of a shot putter.

Why the difference? Our correspondent mentions that he has heard theories that females have an extra bone that prevents them from throwing "like a boy." Or is it that they are missing one bone?

We talked to some physiologists (who a.s.sured us that boys and girls have all the same relevant bones) and to some specialists in exercise physiology who have studied the underperformance of girls in throwing.

In their textbook, Training for Sport and Activity: The Physiological Basis of the Conditioning Process, Jack H. Wilmore and David L. Costill cite quite a few studies that indicate that up until the ages of ten to twelve, boys and girls have remarkably similar scores in motor skills and athletic ability. In almost every test, boys barely beat the girls. But at the onset of p.u.b.erty, the male becomes much stronger, possesses greater muscular and cardiovascular endurance, and outperforms girls in virtually all motor skills.

In only one athletic test do the boys far exceed the girls before and after p.u.b.erty: the softball throw. From the ages of five to sixteen, the average boy can throw a softball about twice as far as a girl.

Wilmore and Costill cite a fascinating study that attempted to explain this phenomenon. Two hundred males and females from ages three to twenty threw softb.a.l.l.s for science. The result: males beat females two to one when throwing with their dominant hand, but females threw almost as far as males with their nondominant hand. Up until the ages of ten to twelve, girls threw just as far with their nondominant hand as boys did.

The conclusion of Wilmore and Costill is inescapable: Major differences at all ages were the results for the dominant arm...the softball throw for distance using the dominant arm appears to be biased by the previous experience and practice of the males. When the influence of experience and practice was removed by using the nondominant arm, this motor skill task was identical to each of the others.

All the evidence suggests that girls can be taught, or learn through experience, how to throw "like a boy." Exercise physiologist Ralph Wickstrom believes most children go through several developmental stages of throwing. Boys simply continue growing in sophistication, while girls are not encouraged to throw softb.a.l.l.s or baseb.a.l.l.s and stop in the learning curve. As an example, Wickstrom notes that most right-handed girls throw with their right foot forward. Simply s.h.i.+fting their left foot forward would increase their throwing distance.

When forced to throw with their nondominant hand, most boys throw "like a girl." The loss in distance is accountable not only to lesser muscular development in the nondominant side, but to a breakdown in form caused by a lack of practice.

Submitted by Tony Alessandrini of Brooklyn, New York.

Given that the ZIP Code Defines the City and State, Why Do We Have to Include Both on Envelopes? Or Do We?

Jack Belck, the true zealot who posed this Imponderable, gave as his return address his full name, a street number, and 48858, with a note: "The above address is guaranteed to work."

Evidently it did. He received a letter we wrote to him in that lovely town, 48858.

But the question is a good one, so we asked our friends at the USPS to respond.

And they were a tad cranky.

Yes, they will deliver letters addressed by the Belcks of the world, but they aren't too happy about it for a couple of reasons. First of all, many people inadvertently transpose digits of the ZIP code. The city and state names then serves as a cross check. Without the city and state names, the letter would be returned automatically to the sender. Even if it is delayed, the postal service will reroute a letter with an incorrect ZIP code.

Secondly, Mr. Belck isn't quite right about one of his premises. In rural areas, more than one munic.i.p.ality might share the same zip code. City names can thus be of a.s.sistance to the local post office in sorting and delivering the mail.

Submitted by Jack Belck of 48858.

Why Do Telephone Cords Spontaneously Twist Up? What Can One Do About this Dreaded Affliction?

Spontaneously twist up, you say? You mean you sit on your sofa watching TV and suddenly the telephone cord starts winding like a snake?

After considerable research into the matter, we must conclude that telephone cords do not twist up spontaneously. You've been turning around the headset, Alan. We're not accusing you of doing this intentionally, mind you. As far as we know, twisting a headset is not even a misdemeanor in any state or locality. But don't try to blame your indiscretions on the laws of nature. Cords don't cause twisted cords-people do.

Now that we've chastised you, we'll offer the obvious, simple yet elegant solution. Remove the plug that connects the headset to the body of the phone. Hold the cord by the plug side and let the headset fall down (without hitting the floor, please). The cord will "spontaneously" untwist.

For those having similar problems with twisted lines connecting their phones to the modular jacks in the wall, simply unplug the line from the phone. If the line is sufficiently coiled, it will untwist like an untethered garden hose.

Submitted by Alan B. Heppel of West Hollywood, California.

Why Do Golf b.a.l.l.s Have Dimples?

Because dimples are cute?

No. We should have known better than to think that golfers, who freely wear orange pants in public, would worry about cosmetic appearances.

Golf b.a.l.l.s have dimples because in 1908 a man named Taylor patented this cover design. Dimples provide greater aerodynamic lift and consistency of flight than a smooth ball. Jacque Hetric, director of Public Relations at Spalding, notes that the dimple pattern, regardless of where the ball is. .h.i.t, provides a consistent rotation of the ball after it is struck.

Janet Seagle, librarian and museum curator of the United States Golf a.s.sociation, says that other types of patterned covers were also used at one time. One was called a "mesh," another the "bramble." Although all three were once commercially available, "the superiority of the dimpled cover in flight made it the dominant cover design."

Although golfers love to feign that they are interested in accuracy, they l.u.s.t after power: Dimpled golf b.a.l.l.s travel farther as well as straighter than smooth b.a.l.l.s. So those cute little dimples will stay in place until somebody builds a better mousetrap.

Submitted by Kathy Cripe of South Bend, Indiana.

Why Don't Crickets Get Chapped Legs from Rubbing Their Legs Together? If Crickets' Legs Are Naturally Lubricated, How Do They Make that Sound?

If we rubbed our legs together for five minutes as vigorously as crickets do all the time, our legs would turn beet red and we would hobble into the bathroom searching for the talc.u.m powder. How do crickets survive?

Quite well, it turns out. For it turns out that we can't believe everything we learned in school. Crickets don't chirp by rubbing their legs together. Entomologist Clifford Dennis explains: Crickets do not produce chirps by rubbing their legs together. They have on each front wing a sharp edge, the sc.r.a.per, and a file-like ridge, the file. They chirp by elevating the front wings and moving them so that the sc.r.a.per of one wing rubs on the file of the other wing, giving a pulse, the chirp, generally on the closing stroke.

On a big male cricket, the sc.r.a.per and the file can often be seen by the naked eye. You can take the wings of a cricket in your fingers and make the chirp sound yourself.

No thanks. We'll take your word for it on faith.

Submitted by Sandra Baxter of Ada, Oklahoma.

Why Is a Navy Captain a Much Higher Rank than an Army Captain? Has This Always Been So?

When one looks at the ranks of the officers of the four branches of the American military, one is struck by how the Army, Air Force, and Marine Corps use the identical ranks, while the Navy uses different names for the equivalents. But there is one striking disparity: the Navy elevates the rank of captain.

Army, Air Force,

Marine Corps

Navy Warrant Officer Warrant Officer Chief Warrant Officer Chief Warrant Officer Second Lieutenant Ensign First Lieutenant Lieutenant Junior Grade CAPTAIN.

Lieutenant Major Lieutenant Commander Lieutenant Colonel Commander Colonel CAPTAIN.

Brigadier General Commodore Major General Rear Admiral Lieutenant General Vice Admiral General Admiral General of the Army or General of the Air Force Fleet Admiral The word "captain" comes from the Latin word caput, meaning "head." In the tenth century, captains led groups of Italian foot soldiers. By the eleventh century, British captains commanded wars.h.i.+ps. So the European tradition has been to name the head of a military unit of any size, on land or sea, a captain.

Our elevation of the English captain stems from English naval practice. In the eleventh century, British captains were not the heads of s.h.i.+ps per se. Although captains were in charge of leading soldiers in combat aboard s.h.i.+p, the actual responsibility for the navigation and maintenance of s.h.i.+ps fell upon the ranks of master. By the fifteenth century, captains bristled at deferring to the masters they outranked, and captains began to a.s.sume the responsibility for the s.h.i.+ps heretofore claimed by masters. By 1747 any commander of a s.h.i.+p was officially given the rank of captain.

Meanwhile, on land most European countries named the commander of a company-of any size-captain. By the sixteenth century, military strategists felt that one hundred to two hundred men were the maximum size for a land unit in battle to be effectively led by one person. That leader was known as a captain.

From the inception of the United States military we borrowed from the European tradition. A captain was a company commander and indeed is so today. In the Air Force, a captain commands a squadron, the airborne equivalent of a company. But the Navy captain, because he has domain over such a big and complicated piece of equipment, has a legitimate claim to a higher rank than his compatriots in the other branches. As Dr. Regis A. Courtemanche, of the Scipio Society of Naval and Military History, put it, Navy captain isn't only a rank. The senior officer of a s.h.i.+p is always called "Captain" even though his rank may only be lieutenant. So a naval captain may have more responsibility than a military captain who usually commands only a small detachment in battle.

In 1862, the Navy realized that it was no longer practical to make captain its highest rank. They needed a way not only to differentiate among commanders of variously sized and equipped vessels but to reward those who were supervising the captains of wars.h.i.+ps. For this reason, the Navy split the rank of captain into three different categories. The commodore (and later, the rear admiral) became the highest grade, the commander the lowest, and the captain, once ruler of the seas, stuck in the middle of the ranks.

Submitted by Barrie Creedon of Philadelphia, Pennsylvania.

Why Do Astronomers Look at the Sky Upside Down and Reversed? Wouldn't It Be Possible to Rearrange the Mirrors on Telescopes?

Merry Wooten, of the Astronomical League, informs us that most early telescopes didn't yield upside-down images. Galileo's original spygla.s.s used a negative lens as an eyepiece, just as cheap field gla.s.ses made with plastic lenses do now. So why do unsophisticated binoculars yield the "proper" image and expensive astronomical telescopes render an "incorrect" one?

Astronomy editor Jeff Kanipe explains: The curved light-gathering lens of a telescope bends, or refracts, the light to focus so that light rays that pa.s.s through the top of the lens are bent toward the bottom and rays that pa.s.s through the bottom of the lens are bent toward the top. The image thus forms upside down and reversed at the focal point, where an eyepiece enlarges the inverted and reversed image.

Alan MacRobert, of Sky & Telescope magazine, adds that some telescopes turn the image upside down, and others also mirror-reverse it: "An upside-down 'correct' image can be viewed correctly just by inverting your head. But a mirror image does not become correct no matter how you may twist and turn to look at it."

O.K. Fine. We could understand why astronomers live with inverted and upside-down images if they had to, but they don't. Terrestrial telescopes do rearrange their image. Merry Wooten says that terrestrial telescopes can correct their image by using porro prisms, roof prisms, or most frequently, an erector lens a.s.sembly, which is placed in front of the eyepiece to create an erect image.

Why don't astronomical telescopes use erector lenses? For the answer, we return to Jeff Kanipe: Most astronomical objects are very faint, which is why telescopes with larger apertures are constantly being proposed: Large lenses and mirrors gather more light than small ones. Astronomers need every sc.r.a.p of light they can get, and it is for this reason that the image orientation of astronomical telescopes are not corrected. Each gla.s.s surface the light ray encounters reflects or absorbs about four percent of the total incoming light. Thus if the light ray encounters four gla.s.s components, about sixteen percent of the light is lost. This is a significant amount when you're talking about gathering the precious photons of objects that are thousands of times fainter than the human eye can detect. Introducing an erector into the optical system, though it would terrestrially orient the image, would waste light. We can afford to be wasteful when looking at bright objects on the earth but not at distant, faint galaxies in the universe.

And even if the lost light and added expense of erector prisms weren't a factor, every astronomer we contacted was quick to mention an important point: There IS no up or down in outer s.p.a.ce.

Submitted by William Debuvitz of Bernardsville, New Jersey.

Does It Ever Really Get Too Cold to Snow?

Having withstood a few snowy midwestern winters in our time, we're not sure we would want to test this hypothesis personally. Luckily, meteorologists have.

No, it never gets too cold to snow, but at extremely low temperatures the amount of snow acc.u.mulation on the ground is likely to be much lower than at 25 degrees Fahrenheit. According to Raymond E. Falconer, of the Atmospheric Sciences Research Center, SUNY at Albany, there is so little water vapor available at subzero temperatures that snow takes the shape of tiny ice crystals, which have little volume and do not form deep piles. But at warmer temperatures more water vapor is available, "so the crystals grow larger and form snowflakes, which are an agglomerate of ice crystals." The warmer the temperature is, the larger the snowflakes become.

What determines the size of the initial snow crystals? It depends upon the distribution of temperature and moisture from the ground up to the cloud base. If snow forming at a high level drops into much drier air below, the result may be no acc.u.mulation whatsoever. In the condition known as "virga," streaks of ice particles fall from the base of a cloud but evaporate completely before hitting the ground.

Submitted by Ronald C. Semone of Was.h.i.+ngton, D.C.

Why Do Dogs Have Black Lips?

You would prefer mauve, perhaps? Obviously dogs' lips have to be some color, and black makes more sense than most.