12 interesting Facts About Microbes

1. Microbes, by weight, represent 60 percent of the biomass of all life on Earth!
2. Microbes outnumber all other species and make up most living matter.
3. Microbes first appeared on earth about 3.5 billion years ago.
4. Microbes generate at least half the oxygen we breathe.
5. 1,000: number of microbial species that normally live on the surface of our skin.
6. Microbes drive the chemistry of life and affect the global climate.
7. A single gram of soil can contain more than a billion microbes!
8. Until birth, the digestive tract is sterile by 48 hours. After birth, microbial colonization is quantitatively similar to that of the adult.
9. Most microbes do not cause disease.
10. 0.000004: diameter in inches of the smallest bacteria.
11. Microbes comprise ~60% of the earths biomass.
12. Pathogen microbes are of three types: viruses, bacteria and protozoans.

Interesting facts about hurricanes

The hurricane season runs from June 1 to November 30. It is rare, but hurricanes have formed in the Atlantic as early as March or as late as December.

The average life span of a hurricane is 9 days.

Apart from hurricane this natural phenomenon is also known by the names of cyclone and typhoon.

Florida has had more hurricanes than any other state in the United States. More than 60 have played there since 1900.

The 'perfect storm' of 1991, made famous by the book and film, was created from the remains of Hurricane Grace.

Hurricanes turn clockwise in the Southern Hemisphere and counterclockwise in the Northern Hemisphere.

Hurricane Katrina killed at least 1,836 people, making it the deadliest hurricane in the United States since Hurricane Okeechobee in 1928.

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Interesting facts about volcanoes

The word "volcano" has its origin in the name of Vulcan (the Greek Hephaestus), god of fire in Roman mythology.

The Earth has more than 1,500 active volcanoes.

Fact: The largest volcano in the world is the Mauna Loa (Hawaii). It has a volume of about 40,000 cubic kilometers, and has an area above sea level of 5,125 square kilometers.

The most common type of lava - called basaltic - usually has erupting temperatures of around 1150-1200 degrees Celsius.

The highest volcano in the world is Ojos del Salado in Chile. It is 6,891 meters high.

More than 80% of the earth's surface is of volcanic origin.

Some 500 million people live in the vicinity of active volcanoes!

Great fact: As you read this, there are 20 active volcanoes erupting in various parts of the world. Between 50-70 volcanoes erupted last year, and 160 in the last decade.

The names of some famous volcanoes are: Mount St. Helena, Mauna Loa, Vesuvius, Mount Rainier and Mount Olympus (on the planet Mars).

The oldest volcano is probably Etna (350,000 years).

The Indonesian volcano, Tambora, which exploded in 1815, threw so much ash into the atmosphere that temperatures dropped considerably the following year around the world. New England, in the eastern United States, suffered severe frost in August.

Fact: The loudest sound in human history was caused by a volcanic eruption in Krakatoa, near Java, in 1883. The sound was so powerful that it was even heard in Australia, about 5,000 kilometers from the Krakatoa volcano.

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An animal without teeth or jaws

There are many animals without teeth, but almost every animal has some kind of jaw, which can open and close for food to enter. Except the anteater!

This strange South American creature does not seem to have a mouth, its snout is tube-shaped and contains neither teeth nor jaws.

So how does the anteater eat?... with its tongue! The anteater has a very long tongue, sometimes more than 30 cm long, and is very sticky. The anteater looks for a mound of ants, which it tears and opens with its legs and licks dozens of ants with a single movement of its tongue. Then, the anteater puts its tongue back into its snout and swallows the ants all at once.

An ant-eating creature may seem harmless, but the anteater is strong and dangerous. It is an animal that has sharp claws on its legs which not only serve to dig but to defend itself from its enemies. And the giant anteater can be as big as a real bear!

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Can you make it rain artificially?

Hopi Indians in the southwestern United States still invoke rain by sacrificing golden eagles and dancing with live rattlesnakes between their teeth. While this is happening, others have adopted a scientific method to make it rain.

In 1946, Vincent Schaefer and Irving Longmuir of General Electric's Research Laboratories in Schenectady, United States, began their work, which proved that rain could be artificially provoked.

Clouds are made up of millions of particles of water too small to precipitate as rain. Only when drops of a quarter of a millimeter or more form do they cause a fine drizzle. The smallest droplets evaporate before reaching land.

One way to make the droplets grow is to turn them into ice. In a cloud with ice particles and water droplets, the former grow rapidly when water vapor is absolved. Since the temperature of the clouds is almost always lower than the freezing point, one would expect the drops to freeze easily. But the water can be below that point without freezing.

This is because the water in the clouds is absolutely pure; it has no dust or contaminants that can form the center of an ice crystal. If particles are added, the droplets freeze, grow rapidly to a size large enough to precipitate, and then melt as the temperature rises to form rain.

Schaefer and Longmuir proved that adding particles to clouds, usually silver iodide, could produce rapidly growing ice crystals. These particles are launched from airplanes, by rockets or by air currents that raise them from the surface.

In the former Soviet Union, 70 mm artillery pieces were used to shoot silver iodide particles into the clouds. Although the technique can work when the clouds have the right temperature, it is impossible to know how much it would have rained without resorting to artifice. And this raises questions about the cost-effectiveness and efficiency of the method.

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What is a glacier

   A glacier is a river or great moving sheet of ice. Rivers of ice are always in valleys. They are often called valley glaciers. Great moving sheets of ice are often called icecaps.
   A glacier begins as a snowfield. Little by little the snow becomes solid ice. The ice grows thicker and begins to move. The snowfield has become a glacier.
   A valley glacier moves down its valley. It may move less than a foot a day. It may move more than a hundred. All valley glaciers move, but some of them do not seem to be doing so. A glacier looks as if it were standing still if the ice at the end melts as fast as more ice is pushed down. An icecap moves outward in all directions. But it may move quite a bit faster at some places than at others.
As glaciers move, great cracks appear in them. These cracks are called crevasses. Crevasses make the exploring of glaciers exciting and dangerous.
   Glaciers scratch the rocks they move over. They grind up rocks, too. As a rule a glacier pushes along great piles of rock rubbish. These piles are called moraines.
   Valley glaciers are common in the Alps and Himalayas. They are common, too, in Norway, Alaska, and western Canada. Glacier National Park, which has several glaciers, is in northwestern United States. Antarctica and Greenland are almost com
pletely covered with big sheets of ice.
   The climate of the world has changed many times. Suppose it should get so warm that all the glaciers melted. Then the water in the oceans would rise 100 feet. A great deal of what is now dry land would then be under the sea.

Where is located Great Salt Lake?

   The largest lake in the western half of the United States is Great Salt Lake. This lake is very different from the Great Lakes. For one thing, it is very shallow. On the average it is less than 15 feet deep. Besides, its water is very salty.
   This lake is left over from a much bigger one—Lake Bonneville. Lake Bonneville once covered most of what is now the state of Utah. It was a great fresh-water lake 1,000 feet deep. Water poured into it down the slopes of surrounding mountains. Through a gap in the mountains overflow water found a way to the sea.
   But in time the climate of the region became much drier. Less water ran into the lake, and much that did evaporated. Finally the lake was losing more water each year than it got. Of course, the lake became shallower and smaller. At last no water ran out of it to the sea. The lake grew salty, for the water as it evaporated left behind the salt it had gathered up from rocks on its way to the lake. Now the water is much saltier than sea water. The only living things in Great Salt Lake are brine shrimps and tiny algae. Swimming in such salty water is a strange experience. The water holds a swimmer up much more than fresh water does. If he floats, a third of his body is out of water. Diving is rather dangerous. A diver may be stunned when he hits the heavy water.
    Along the northwest shore of the lake are the Bonneville Salt Flats. "Flats" is a good name for them, for they are probably flatter than any other natural surface on the earth. The ground is almost pure salt. On the Flats there is an automobile racecourse. A racing car has traveled nearly 400 miles an hour on it.
   Salt Lake City is near Great Salt Lake. Some of the people of the city earn their living by mining salt. Lake Bonneville left behind enough salt to last the whole world for a thousand years.
   The best way to get a good view of the lake is to fly over it. On a sunshiny day the very blue lake with its border of salt makes a picture it is not easy to forget.

What is dew?

   On sunshiny summer mornings the grass is often wet with dew. It may be so wet that it is hard to believe that there has not been a shower. There may be drops of dew on flowers and bushes and spider-webs, too. The drops of dew sparkle like jewels when the sun shines on them.
   Drops of dew look like drops of rain. But they do not fall from clouds as rain-drops do. They are formed where they are found. They are formed from the water vapor in the air when moist air strikes something cold. Cold air cannot hold as much moisture as warm air.
   Drops of water form on the outside of glasses of cold water or lemonade on hot summer days. They form when the warm, moist air strikes the cold glass. They are like drops of dew.
   Dew is formed much oftener in fair weather than in cloudy weather. On clear nights things near the ground cool off much faster than on cloudy nights. Clouds act as a kind of blanket. Unless flowers and leaves and spiderwebs are cooler than the air, dew will not form on them.
   Wind also keeps dew from forming. On a windy night the air is constantly moving about. None of it stays near the cool ground long enough to be cooled off and to lose some of its moisture.
   Dew does not stay on very long after the sun comes up. The grass and other things on which the dew has formed soon get warm. Then the dew changes again to water vapor. This same water vapor may become dew again the next night if the weather is calm and fair.

What is Nature?

   Nature is the term often used for the total of the forces which produce the forms of life and of matter. These forces seem to operate according to certain patterns, or laws; thus the laws are called "natural." Whenever anything happens which does not seem to be in keeping with these laws, the occurrence (phenomenon) is called "supernatural."

What is the eye of the storm?

   Eye of the storm is the calm center of the hurricane or typhoon. In areas struck by hurricanes and typhoons, people sometimes venture out of their shelters when the winds become light. People who are acquainted with the structure of hurricanes, however, know better than to be deceived by the calm and the clear skies. This is the eye. Around the eye swirl the terrible winds of the storm. The eye of the storm varies from 5 to 40 miles in diameter and is surrounded by dense clouds to an average height of 18,000 feet.
   Although the eye of the storm gives temporary relief to people on land, it does not help sailors. Within the calm area a thunderous cross sea crashes over ships.

What is a Cloudburst?

   At times rain pours down so fast that it is as if an enormous bag full of water had burst open and spilled all its water at once. A rain of this kind is called a cloudburst.
   A cloud cannot really burst. A rain cloud has nothing on the outside to shut in its billions of droplets of water. But, even when the droplets become big drops, strong upward currents of air may keep them from falling. At last, however, the drops are too big and heavy to be held up. They fall with a rush, and we have a cloudburst.
   In a cloudburst enough rain to make a layer several inches deep on the ground may fall in a very short time. In Holt, Mo., for instance, 12 inches of rain fell in one hour on June 22, 1947. This is more rain than many parts of the world get in a year. And in Jefferson, Iowa, two-thirds of an inch fell in just one minute on July 10, 1955!

Moraine

A moraine is a mass of stones and earth deposited by melting glacial ice. Many of the large boulders and earth formations in the northern United States remain from the melting GLACIERS of the Glacial Ice Age.
   Moraines are classified according to the pattern in which rocks and earth were left by a glacier. Major types of moraines are the terminal, lateral, medial, and ground.
   Glaciers do not sort the material they carry; the material is of all sizes. The moraine left at the end of the glacier after it melts is called a terminal moraine. It is usually piled up in an irregular ridge, or hill, and marks the farthest point the glacier reached. The unsorted material in a moraine is often called glacial drift or till.
   Lateral moraines consist of earth and rocks heaped along the margins of a glacier. Lateral moraines leave two somewhat parallel lines of material by which the path of a glacier may be traced.
   Medial moraines occur where two valley glaciers came together. The lateral moraines of each join to form a medial (middle) moraine down the center of the new larger glacier, forming the shape of a large Y.
   A ground moraine consists of earth and rock that are deposited beneath a melting glacier.

What is a fault?

   Fault is a fracture or break in the earth's crust along which movement has occurred. The earth on one side of the fault may move upward, downward, or sideward in relation to the other side of the fault. As a result, cliffs and basins and troughs may be formed. Faulting in layered rocks may result in one layer being raised or lowered or tilted in relation to the same layer on the opposite side of the fault. Faults generally accompany mountain building.

What is a water cycle?

   A water cycle is the round-trip story of a raindrop. The cycle starts in oceans, seas, and lakes. When the sun shines, the air is warmed and it acts like a sponge. The heat of the sun slowly turns the water into a gas which is called water vapor. This process is called evaporation. Warm air is lighter than cold air, thus the cold air pushes the warm air upward. As it moves upward, currents of air develop; these air motions are called winds. When the warm, moist air passes over mountains, or when these warm air masses rise high above the earth, they are cooled. Cooling causes the water vapor to condense to the liquid form.

   The raindrop is formed out of many condensed particles of water vapor. The condensations get heavier as they fall through more condensing water vapor, pulled toward the surface of the earth by gravity.

How does an iceberg form?

   A iceberg is a fragment of a glacier floating about in the sea. If a glacier on the coast pushes out into the sea faster than it wastes away, a mass. of ice breaks off sooner or later and floats away. The floating ice is then called an iceberg. The icebergs of the North Atlantic are formed chiefly on the shores of Greenland. Some of the blocks measure a mile or more across, and are from 1,200 to 1,500 feet in thickness. As ice is lighter than water an iceberg floats like a chip, but it should be remembered that only the small end is above water, possibly one-tenth of the bulk. An iceberg extends five or six times as far beneath the surface of the water as it does above. The warm waters which prevail along the north-western coast of Europe melt the icebergs before they drift farther south than 70° of north latitude. On the American coast they drift as far south as the banks of New-foundland. Seen in the daytime and in clear weather, icebergs are often very beautiful. Minarets and towers glitter in the sun like fairy work, but they are none the less a source of real danger to ships, especially in dark nights and amidst the fogs that prevail. As icebergs are formed on land their water is fresh and is often relied upon for use on board ship. An iceberg must be approached with caution, however, because splinters and slivers are likely to fall at any time. Although the North Pa­cific Ocean is approached by magnificent glaciers, icebergs are by no means so prominent as in the North Atlantic. The ice­bergs of the southern hemisphere, if we except the region of Cape Horn, seldom interfere with navigation.

What is a fumarole?

   A fumarole is an opening in the earth's crust, usually in a volcanic region, from which steam and gases issue. The gases are usually carbon dioxide, hydrochloric acid, and hydrogen sulfide. The world's largest area of fumaroles is the Valley of Ten Thousand Smokes, near Katmai Volcano in Alaska.

Deserts

   In the northern part of Chile several years may go by without a single drop of rain. There are not many parts of the world as dry as that. But large areas get very little rain or snow. We call such regions deserts.
In all deserts there is very little water for plants to use. But not all deserts are dry. In the Far North there are deserts even where there is much water in the soil. But a few inches below the top of the ground the water is always frozen. There are other deserts that have water, but it is too salty for plants to use..One such desert is near Great Salt Lake in Utah. But most people think of hot, dry deserts when they hear the word "desert." The Sahara in Africa is the world's largest hot, dry desert. The Gobi Desert in Asia is another very large one.
Such deserts usually have great stretches of bare sand. Winds pile up the sand into hills, or dunes. Scattered through the des­erts there may be oases, where trees and other plants grow. Springs or streams fed by rain or snow far away furnish the needed water for green oases.
   Night can be cold in a hot, dry desert. In the air there is very little water to act as a blanket, and the heat of the day escapes very fast as soon as the sun goes down. Scorching heat in the daytime and shivering cold at night is the rule.
   Dry deserts, oddly enough, can have bad floods. Any rain that falls is likely to come in heavy showers, the kind we call cloud-bursts. The rain cannot sink into the ground as fast as it falls. It rushes off into small streams and makes the streams overflow. Many travelers in a desert have been stopped by floods.
Often there are sandstorms in dry des­erts. There is nothing to break the wind as it blows over the great stretches of sand.
   Some plants and animals are fitted for living in deserts. Some desert plants have very long roots that can get water from deep in the ground

What is a delta?

   A river almost always carries a load of sand and mud and pebbles. Many rivers carry their loads to the sea. When the water of a river strikes the sea, it is slowed up. In most cases it cannot carry its load far. It drops first the pebbles, then the sand, and then the mud. It may drop so much that a f an of land is built up at the mouth of the river.
   Such a fan of land is called a delta. It got its name because it is a little like the shape of the Greek letter called delta. Delta is the Greek letter from which our D came. It is shaped like this: Δ.
In the Old World one of the most famous deltas is the delta of the Nile. Much of the fertile land of Egypt is in this delta. The delta helped ancient Egypt become one of the cradles of civilization.
   In the United States there is a great delta at the mouth of the Mississippi River. The city of New Orleans is many miles north of this delta. But at one time the land where New Orleans stands was, scientists believe, a part of the Mississippi delta. Over many centuries, the river kept on bringing down millions of tons of mud and sand to it each year. The mouth of the river—and its delta —kept moving farther and farther south. As more years continue to go by, the delta of the Mississippi is almost sure to extend even farther out into the Gulf of Mexico than it does now.
   The Amazon, the Ganges, the Indus, and the Rhine are other rivers that have built up big deltas. Some rivers flow too swiftly to build a delta. The Congo is one.

What is fog?

Fog is a body of microscopically small drops of water condensed from the air. This body of water, sus­pended near the surface of the earth, reduces horizontal visibility to 0.6 mile or less. As the droplets become larger, fogs merge gradually into a drizzle.
   Fog is usually formed when a body of moist warm air comes in contact with cold land or sea. The cold causes the invisible water vapor to condense and become visible as a mass of tiny particles of water.
   In a sea fog warm air is carried over cold water. For example, off Newfoundland fogs form when the air from the south blows over the cold waters of the Labrador Current. Such a fog is called an advection fog, one produced by the movement of moist air over a cold sur­face. An evaporation fog, or steam fog, is produced when cold air moves over warm water; moisture may be evaporated from the water and added to the cold air to the point of saturation.
   A thick fog lying close to the ground, formed when moist surface air is cooled at night, is one type of radiation fog. The other type of radiation fog is a high-inversion fog, in the form of a low stratus cloud. In an upslope fog, cooling is due to the ascent of moist air moving against a mountainside.
During the day fog is usually evaporated as the sun warms the cool air and allows it to hold more water.
   Advection, radiation, and upslope fogs are all produced chiefly by the cooling of air to its dew point. Such fogs are classified as air-mass fogs. Another main classification of fogs, called frontal fogs, includes fogs produced when vapor from falling rain raises the dew point while other factors lower the temperature.

What is a dune?

   A dune is a hill of sand. Dunes are found along shores of lakes and oceans and in sandy deserts. Some of the biggest dunes in the world are on the shores of Lake Michigan.
   Dunes are built by the wind. A small plant may start a dune. Wind carrying a load of sand strikes the little plant and drops part of its load. The sand forms a tiny hill in front of the plant. Now the wind strikes the tiny hill and drops more sand. Little by little the hill grows.
   In one way dunes are very different from other hills—they go traveling. The wind blows sand up one side of the hill and over the top. The sand rolls down on the other side. In this way the dune slowly moves. Sometimes a moving dune buries a forest. Sometimes it moves on past and leaves a forest graveyard behind it.
   There are many dunes that are no longer traveling. This is the story of almost every dune that has stopped moving: A newer dune first shut off much of the wind. Then small plants began to grow on the old dune. These plants helped protect the surface sand from the wind. Bigger plants could then grow and hold the dune in place. Some dunes have forests on them.