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Wonders shall never end

Fri, 13 Nov 2009 01:50:25 +0100

A CAMEL needs about as much water as a horse. When water is available, the animal will drink from five to seven gallons a day. However, the remarkable thing about the camel is that it can live without water for a prolonged period. Carrying a load of some 400 pounds, it may endure without water for eight days. An exceptional record for a camel is 34 days without drinking water.

When the Moon Appears Upside-down

Fri, 13 Nov 2009 01:30:24 +0100

HAS the moon ever appeared inverted or upside-down to you? Likely you know the experience if you have ever traveled into the southern hemisphere from the northern, or vice versa. One doing so may surprisingly exclaim: “The moon is upside-down!” Actually crossing the equator from one hemisphere to another results merely in a different vantage point of observation. Even the sun, which continues to travel in the same direction that one is accustomed to, now seems to be closer to the opposite horizon. It is merely the observer’s point of view that has changed.

Insects Made It First!

Sat, 17 Oct 2009 23:47:24 +0100

The well-known polyesters that have proved so useful for fabrics and other purposes are usually considered to be a man-made product. However, according to Science magazine, researchers have found what “appears to be the first report of a naturally occurring linear polyester.” Bees of the genus Colletes secrete a substance to line cells formed in the earth for housing their eggs. Once the substance is spread, a still unknown process (possibly enzymatic) polymerizes it, and the resulting polyester protects the bee larvae from water, fungi and soil microorganisms. The tough natural polyester is said to resist decay for more than a year.

The world's famous track and field animal

Tue, 08 Sep 2009 13:26:27 +0100

The sky over South America’s rain forest was turning that hard-to-describe color it gets right before the tropical night erases the color. Then, suddenly and silently, there the puma was! It had warily stepped into a forest clearing and stopped in its tracks.

For a moment the big cat stood motionless, except for the tip of its tail, which kept moving like a low-speed windshield wiper. Then, when it noticed that it was being watched, the puma leapt across the clearing and dashed into the forest with lightening speed

Bundle of Muscles

Because of its plain, tawny color, the puma may remind you of a lioness. Long and sturdy hind legs cause its rump to be higher than its shoulders. Those powerful legs give this 130-pound [60 kg] bundle of muscles the booster power to blast off the ground like a rocket. Pumas have been seen to leap vertically to a height of 18 feet [5 m] in one big jump. That’s like pole-vaulting without bothering to use a pole!

When jumping down, the puma is equally impressive. It has been known to make flying jumps to the ground from a height of 60 feet [18 m]. This is nearly twice the height of platforms used by Olympic platform divers, but the puma doesn’t have the benefit of a filled swimming pool below. Even so, the cat hits the ground ready to bound away as if it had landed on a trampoline.

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When the first colonists settled in the New World, the puma’s range spanned the entire continent, from the Atlantic to the Pacific. It made a living in mountains, swamps, prairies, and jungles alike. Though hunters and farmers have now eliminated the puma from many parts of North America, it remains the all-American cat, still wandering from Canada to the tip of South America. If you measure the success of an animal by the extent of its geographic distribution and the diversity of its habitat, then the puma must be the most successful native American mammal today. The secret of its success?

The puma is well equipped for survival. It has a sturdy stomach and uses varied hunting methods. It can adjust to almost any kind of local food. “It is able to kill and drag an animal five times its size, but it also eats grasshoppers if nothing else is around,” says a veterinarian who has examined the stomach contents of several pumas killed in Brazil. “When it comes to food, the puma is more versatile than any other species of cats.”

Diverse food also calls for diverse hunting skills. Grabbing, let’s say, a bird requires a different tactic from pouncing on a deer. How does the puma do it? In Brazil’s Atlantic forest, it attracts the tinamou by imitating the bird’s call. “A perfect imitation,” says one observer. “The tinamou calls only a few times, but the puma whistles on—10 or 20 times.” Nevertheless, it works. The tinamou thinks a noisy male bird has invaded his territory and decides to step forward and confront his rival—a fatal move.

Whether you search for the puma in North, Central, or South America, it manages, for the most part, to stay out of sight—like the air, omnipresent but invisible. The adjectives most often used by researchers studying the puma are “secretive, elusive and wary.” After killing about 70 pumas, one hunter admitted that “he had never seen one of his victims before the dogs had driven it up a tree.” No wonder frustrated researchers have called the cat “maddeningly elusive”!

What an amazing animal. A wonderful work of nature.

A Tree Can Sing

Tue, 08 Sep 2009 11:26:27 +0100

In the boundless grasslands of Africa stands a tree that often sings. The tree is of the acacia species and is known as the whistling thorn. Why? Because when the wind rushes through the delicate branches, the tree seemingly lifts its voice.

A lovely, lilting sound is produced when the tree’s unusually long and slender thorns vibrate in the wind. Adding to the melody of the thorns, the tree’s hollow galls produce a sound much like that of an empty bottle when air is blown across its mouth. These "instruments" are formed by ants, who are said to hollow out the galls, the ants’ spherical homes, and carve tiny entrance and exit holes in them. Because the galls and holes are of differing sizes, they produce sounds of differing pitch. These sounds add to the uniqueness and beauty of the whistling thorn.

A wonder of nature.

Your Ear—The Great Communicator

Tue, 23 Jun 2009 21:28:50 +0100

YOU can close your eyes when you do not want to see. You can hold your breath when you do not want to smell. But you cannot really shut down your ears when you do not want to hear. The saying “to turn a deaf ear” is only a metaphor. Your hearing, like your heartbeat, goes on working even when you sleep.

Indeed, our ears are working all the time to keep us in touch with the world around us. They select, analyze, and decipher what we hear and communicate it to the brain. Within the confines of about one cubic inch [16 cu cm], our ears utilize principles of acoustics, mechanics, hydraulics, electronics, and higher mathematics to accomplish what they do. If our hearing is not impaired, consider just a few of the things the ears can do.

□ From the softest whisper to the thunderous roar of a jet plane taking off, our ears can cope with a 10,000,000,000,000-fold difference in loudness. In scientific terms, this is a range of about 130 decibels.

□ Our ears can pick out and focus on one conversation across a room full of people or detect a wrong note played by one instrument in an orchestra of a hundred.

□ Human ears can detect a change of just two degrees in the direction of a sound source. They do this by sensing the minute difference in the arrival time and the intensity at the two ears. The time difference may be as little as ten millionths of a second, but the ears can detect this and convey it to the brain.

□ Our ears can recognize and distinguish between some 400,000 sounds. Mechanisms in the ear automatically analyze the sound wave and match it with those stored in our memory bank. That is how you can tell if a musical note is played by a violin or a flute, or who is calling you on the phone.

The “ear” we see at the side of our head is really only a portion, the most visible portion, of our ear. Most of us probably still remember from our school days that the ear is made up of three sections: outer, middle, and inner ears, as they are called. The outer ear consists of the familiar “ear” of skin and cartilage and the ear canal leading inward to the eardrum. In the middle ear, the three smallest bones in the human body—the malleus, incus, and stapes, commonly called hammer, anvil, and stirrup—form a bridge linking the eardrum with the oval window, the portal to the inner ear. And the inner ear is made up of two strange-looking parts: the cluster of three semicircular canals and the snail-shaped cochlea.

Outer Ear—The Tuned Receiver

Obviously, the external ear serves to collect sound waves in the air and channel them to the inner parts of the ear. But it does much more than that.

Have you ever wondered if the convoluted shape of the external ear serves any specific purpose? Scientists find that the cavity at the center of the external ear and the ear canal are so shaped that they enhance sounds, or resonate, within a certain frequency range. How does that benefit us? It so happens that most of the important characteristics of human speech sounds fall in about the same range. As these sounds travel through the external ear and the ear canal, they are boosted to about twice their original intensity. This is acoustical engineering of the highest order!

The outer ear also plays an important role in our ability to locate the source of sound. As mentioned, sounds coming from the left or right of the head are identified by the difference in intensity and arrival time at the two ears. But what about sounds that come from behind? Again, the shape of the ear comes into play. The edge of our ear is shaped in such a way that it interacts with sounds coming from behind, causing a loss in the 3,000- to 6,000-Hz range. This alters the character of the sound, and the brain interprets it as coming from behind. Sounds from above the head are also altered but in a different frequency band.

Middle Ear—A Mechanic’s Dream

The job of the middle ear is to transform the acoustical vibration of the sound wave into mechanical vibration and pass it on to the inner ear. What takes place in this pea-sized chamber is truly a mechanic’s dream.

Contrary to the notion that loud sounds cause significant movement of the eardrum, sound waves actually do so by only microscopic amounts. Such minuscule movement is hardly enough to cause the fluid-filled inner ear to react. The way this obstacle is overcome demonstrates once again the ingenious design of the ear.

The linkage of the three little bones of the middle ear is not only sensitive but also efficient. Functioning as a lever system, it magnifies any incoming forces by about 30 percent. Furthermore, the eardrum is about 20 times larger in area than the footplate of the stirrup. Thus, the force exerted on the eardrum is concentrated on a much smaller area at the oval window. These two factors together amplify the pressure at the vibrating eardrum to 25 to 30 times as much at the oval window, just enough to set the fluid in the cochlea in motion.

Do you find that a head cold sometimes affects your hearing? This is because proper operation of the eardrum requires that the pressure on either side of it be equal. Normally this is maintained by a small vent, called the Eustachian tube, that connects the middle ear with the back of the nasal passage. This tube opens every time we swallow and relieves any pressure build-up in the middle ear.

Inner Ear—The Business End of the Ear

From the oval window, we come to the inner ear. The three mutually perpendicular loops, called the semicircular canals, enable us to maintain balance and coordination. It is in the cochlea, however, that the business of hearing really begins.

The cochlea (from Greek ko·khli´as, snail) is basically a bundle of three fluid-filled ducts, or canals, coiled up in a spiral like the shell of a snail. Two of the ducts are connected at the apex of the spiral. When the oval window, at the base of the spiral, is set in motion by the stirrup, it moves in and out like a piston, setting up hydraulic pressure waves in the fluid. As these waves travel to and from the apex, they cause the walls separating the ducts to undulate.

Along one of these walls, known as the basilar membrane, is the highly sensitive organ of Corti, named after Alfonso Corti, who in 1851 discovered this true center of hearing. Its key part consists of rows of sensory hair cells, some 15,000 or more. From these hair cells, thousands of nerve fibers carry information about the frequency, intensity, and timbre of the sound to the brain, where the sensation of hearing occurs.

Our ears may not be the most acute or most sensitive among ears, but they are eminently suited to fulfill one of our greatest needs—the need to communicate. They are designed to respond especially well to the characteristics of human speech sounds. Infants need to hear the sound of their mother’s voice to grow properly. And as they grow, they need to hear the sounds of other humans if they are to develop their faculties of speech. Their ears allow them to discern the subtle tonal inflections of each language so precisely that they grow up speaking it as only a native can.

Survival Secrets

Thu, 14 May 2009 18:15:17 +0100

Natural Antifreeze. Humans have fantasized for years about the time when they would be able to deep-freeze someone and restore him to life sometime in the future. For some frogs, however, this is no fantasy. They do it every year.

Like other animals, frogs are faced with the problem of surviving winter without central heating or hearth fires. Their solution? They “just squat in the open until they freeze solid,” says a report in The Toronto Star. When spring comes around, the frog thaws out and starts croaking again.

Why doesn’t the freezing kill him? Biologist Kenneth Storey says: “We found frogs produce an anti-freeze molecule that we didn’t expect at all: glucose. People had said there was no way to use that as an anti-freeze, but frogs can.” Seemingly, because of this glucose, when the frog freezes, its tissue fluids turn to syrup instead of forming ice crystals that would expand and rupture its cells.

Anti-Antifreeze. The magazine Science Digest reports that certain creatures in Antarctica have a natural antifreeze that helps them keep moving in cold weather. However, when the temperature gets too low, they freeze and die. A tiny wingless fly—whose name, Belgica antarctica, is much bigger than he is—also uses the natural antifreeze to keep moving in ordinary cold weather. But when very cold weather threatens, he uses an “anti-antifreeze” chemical to survive. Long before the temperature gets dangerously low, the “anti-antifreeze” stops the action of the antifreeze. Why?

“By inducing the insect to freeze at fairly warm temperatures, the special anti-antifreeze compound insures that ice forms at a slow rate. At lower temperatures, rapid freezing would remove water from its cells too quickly, and the animal would die as a result.” But since Belgica antarctica freezes gently, he survives and simply thaws out when the temperature rises again.

And the Smart Potato. A perennial problem for farmers is controlling infestation by aphids such as the greenfly. According to a report in the Daily Mail, it seems that one type of potato has solved the problem all by itself.

Scientists in Hertfordshire, England, discovered that the potato plant Solanum berthaultii produces a chemical that is exactly the same as that given off by a dying aphid to warn other aphids. The plant is left in peace as aphids, alarmed by the chemical, give it a wide berth.

Oil? It Can Grow on Bushes!

Mon, 27 Apr 2009 22:13:09 +0100

THE sperm whale has been hunted with a persistence that has endangered existence of its kind. Factory-ship whaling has been banned, but it is estimated that these giants of the sea are still taken at the rate of about one every half hour. Why?

A large sperm whale yields several tons of sperm oil and spermaceti—a white waxy substance. Both of these substances are very valuable and bring wealth to the whalers.

Nevertheless, under pressure from conservationists, all countries, except Russia and Japan, have given up hunting them; and yet they have great difficulty in finding satisfactory substitutes. The oil is used for high-pressure lubrication, in protecting machine tools, in pharmaceuticals, cosmetics and other products.

However, there is an alternative that is highly suitable—the jojoba (pronounced hohóba) bush. It grows wild in the deserts of Arizona, California and Mexico. Recent research reveals that jojoba oil can do all that sperm oil does—and better.

A jojoba bush grows about 3 m (10 feet) and after five years can produce 2.5 kg (5.5 lbs.) of beans annually. Oil yield is about 50 percent and the residue makes cattle feed.

The plants are really tough. The waxy coat on the evergreen leaves prevents drying out, so a jojoba bush can take great heat, can stand a year without water and can be grown in poor soil where nothing else grows. And they can live 100 years!

Israel has already many experimental plantations of jojoba in the Negev. It is said that the bushes can even be irrigated from the salty waters of the Dead Sea. In the drier parts of Cape Province, South Africa, many farmers are also raising jojoba plants. With oil becoming such a coveted commodity, growing it on bushes would not only benefit the long-suffering whale population but also be a very paying project.

Diary of an Unborn Child

Sat, 18 Apr 2009 14:39:56 +0100

OCTOBER 5:

Today my life began. My parents do not know it yet, but it is I already. And I am to be a girl. I shall have blond hair and blue eyes. Just about everything is settled though, even the fact that I shall love flowers.

OCTOBER 19:

Some say that I am not a real person yet, that only my mother exists. But I am a real person, just as a small crumb of bread is yet truly bread. My mother is. And I am.

OCTOBER 23:

My mouth is just beginning to open now. Just think, in a year or so I shall be laughing and later talking. I know what my first word will be: MAMA.

OCTOBER 25:

My heart began to beat today all by itself. From now on it shall gently beat for the rest of my life without ever stopping to rest! And after many years it will tire. It will stop, and then I shall die.

NOVEMBER 2:

I am growing a bit every day. My arms and legs are beginning to take shape. But I have to wait a long time yet before those little legs will raise me to my mother’s arms, before these little arms will be able to gather flowers and embrace my father.

NOVEMBER 12:

Tiny fingers are beginning to form on my hands. Funny how small they are! I’ll be able to stroke my mother’s hair with them.

NOVEMBER 20:

It wasn’t until today that the doctor told mom that I am living here under her heart. Oh, how happy she must be! Are you happy, mom?

NOVEMBER 25:

My mom and dad are probably thinking about a name for me. But they don’t even know that I am a little girl. I want to be called Kathy. I am getting so big already.

DECEMBER 10:

My hair is growing. It is smooth and bright and shiny. I wonder what kind of hair mom has?

DECEMBER 13:

I am just about able to see. It is dark around me. When mom brings me into the world it will be full of sunshine and flowers. But what I want more than anything is to see my mom. How do you look, mom?

DECEMBER 24:

I wonder if mom hears the whispering of my heart? Some children come into the world a little sick. But my heart is strong and healthy. It beats so evenly: tup-tup, tup-tup. You’ll have a healthy little daughter, mom!

DECEMBER 28:

Today my mother killed me.

Plants That Manufacture Insect Repellents

Sat, 18 Apr 2009 13:58:58 +0100

When insects detect anything like sugar they react as many people—they start to eat! But the plant Ajugara remota foils this urge to eat by its own special chemical compound, ajugarin-1. It blocks the insect’s receptor sites and eliminates its desire to munch on Ajugara remota. This chemical is just one of many anti-feedant compounds found among many members of the plant world. Some anti-feedants repel a broad range of insects; others spoil the appetites of only a single species. All are nonpoisonous.

Scientists are trying to make anti-feedants in their laboratories to repel crop-eating insects. Perhaps next they can make anti-feedants that will turn off sugar-hungry humans