Sunday, 20 May 2012


Bacteria are living beings ) organisms ) so small that they can be seen only with a microscope which enlarges several hundred times. Therefore, they are called ''micro-organisms''.
Long before people were able to see bacteria, they knew about the results of bacteria at work. For example, people knew about the results of bacteria at work. For example, people knew that wine ferments, milk turns sour, and dead plants and animals decay. But people had superstitious or religious beliefs as to why this happened. Today, we know that bacteria are all about us-in the air, in water, in food, on the skin, and even inside the body. Bacteria multiply by splitting in half. There are no males or females among bacteria. If they have the right conditions and food for living, they will simply multiply and keep on multiplying.
Bacteria have only one cell which is more like that of a plant than an animal. The outside is a skinlike cover, or ''membrane,'' which is not waterproof. The inside is filled with a material called ''protoplasm'' and usually does not have a single center, or nucleus.
The outside cover is important because any chemical used to destroy the bacteria must be able to pass through the membrane. Around the whole is a slimy material which can change shape and oftern forms tiny threadlike tails, called ''flagella.'' Bacteria can move, although they have no feet. Some move by waving the flagella, and others seem to move by shortening and lengthening the cell, the way worms move.
Bacteria, as we know, cause diseases which we call ''infections.'' But bacteria can also be very helpful and useful to human beings.


A ''mineral'' is any substance found in the earth's crust that does not come from a living thing.
Sometimes petroleum, coal, and limestone are called minerals, but since they were made from plants or animals which lived on the earth a long time ago, they are not really minerals.
Minerals are usually divided into two groups, metallic and nonmetallic. Examples of metallic minerals are hematite ( iron ), bornite ( copper ), and bauxite ( aluminum ). The non-metallic minerals include quartz, asbestos, and calcite. Minerals are usually found n forms called ''crystals.''
It is easy to confuse minerals and rocks, but there is a difference. A mineral has a definite composition. The chemical make-up of a mineral is almost always the same, no matter where it is. So a mineral foud in any part of the world will have the same luster, hardness, and other properties.
Rocks, however, are made up of mixtures of several minerals.For example, granite is a rock made up of minerals like quartz, feldspar, mica and others. But a piece of granite found in one place might have different amounts of these minerals from a piece of granite in another place.
Minerals are found in many places. They may be found in rocks or in sands and gravels. And they are formed in many different ways. Many minerals crystallized or hardened years ago from a very hot, melted mass of rock, called '' a magma.'' Diamond, mica, and feldspar are examples of minerals that formed from moten magma.
Certain minerals, chiefly because of their beauty and scarcity, are very valuable. These are called ''gems'' Some examples of valuable gem minerals are diamond, garnet, topaz, and zircon.
Some minerals, on the other hand, are found almost everywhere. The most common mineral is quartz. There are about 200 different kinds of quartz and it is found in almost every part of the earth.


When this theory was first published, it was said that it could be understood by only a dozen or so scientists in the whole world! So obviously, we cannot even begin to try to explain it in any technical detail in this website. But it should be useful to have a general idea of what Einstein was dealing with, the problem he was concerned with.
Everybody knows from experience that all motion is ''relative.'' This means that it can only be measured in relation to something else. For example, you're sitting in a railroad train and you look out the window. As you see things moving by quickly, you know you're in motion. But ther's a man sitting opposite you, and relative to him you're not moving at all!
So the existence of motion can have meaning only when it is considered relative to something which is fixed. That's the first basic part of Einstein's theory. We may state it as: The motion of a body traveling at uniform speed through space cannot be detected by observation made on that body alone.
The second basic part of Einstein's theory said that the only absolute unchanging quantity in the universe was the speed of light. Now, we know this to be about 186,000 miles per second. But it is really a fantastic idea to be able to imagine that this cannot change. here is why this is so strange: If a car is going at 60 miles an hour, we mean that its speed, measured by a someone standing still, is 60 miles an hour, we mean that its speed, measured by a someone standing still, is 60 miles per hour. If itt passes a car traveling in the same direction at 40 miles per hour, it passes it at a speed of 20 miles per hour. And if the second car, instead of traveling in the same direction, were coming to meet it, they would pass each other at a speed of 100 miles per hour.
Now, according to Einstein, it the speed of a ray of light were measured in the same way ( for example, if we were racing in one direction and it was going the opposite way ), it wouldn't make any difference! That ray of light would still pass at about 186,000 miles per second. This is only the rough, general idea of what Einstein was dealing with in his theory of relativity.Among other things he deal with were mass and energy and how they can be transformed into each other.


As you know from reading the news columns, the greatest goal of science today is to obtain energy from the atom to enable man to live a life of peace and plenty. The mere idea that this can be done is one of the greatest steps forward in the history of human thought!
Albert Einstein was the first man to set up a theory that measured matter in terms of energy. In other words, he showed that matter could be changed into energy. This changed our whole way of looking at the physical world.Matter became secondary; energy became the most important thing in the physical world.
What is energy? Energy is the ability to do work. Energy is that which stands back of forces, and makes the forces possible. Let's try to understand this by considering the automobile.
To make the motor go, a force must be used. Something must provide that force. That something is energy. Where does it come from? It comes from the petrol, and the energy is let loose by burning the petrol in the cylinder. This energy puts certain forces into operation, forces which produce motion through the gears and wheels of the car. The result is that the engine does work, and energy has made it possible.
There are two kinds of energy, potential and kinetic. Firest let's understand potential energy. In the case of petrol, the molecules are held together by electrical forces. Energy is stored in these molecules, potential energy. When the petrol explodes, that potential energy is used up.
Another example of potential enegy is a suspended weight. There is stored-up energy in the weight which we can release just by letting it drop.Water at the top of a falls or behind a dam also has potential energy is used up.
Now suppose the weight drops, or the water goes down over the falls. The mere fact that it is moving at a certain speed enables it to do work, and this energy is called ''kinetic energy.'' It is energy that is derived from the weight of a moving body and its speed. As a body falls, it loses potential energy and gains kinetic energy. But the amount gained is exactly equal to the amount lost. In fact, the total amount of energy in the universe is alwasys the same. We can't create it or destroy it. What we do, whether we use falling water, coal, or tha atom, is change it from one form to another.

Thursday, 17 May 2012


There are thought to be 16 different species of hedgehog found around the world although, oddly enough, there are no species of hedgehog that are native to Australia and no living species of hedgehog that are native to North America. The spikes of the hedgehog are hollow hairs that are made from the protein keratin (the same stuff that human hair and fingernails are made from), and unlike the spikes of the porcupine, the spikes of the hedgehog cannot be removed easily. The spikes of the hedgehog also differ from the spikes of the porcupine as the hedgehog spikes are not poisonous or barbed.

When baby hedgehogs get to a certain age, the young hedgehog will shed the softer baby spikes that are then replaced with the stronger and darker spikes of theadult hedgehog. Hedgehogs have also been known to shed a number of spikes when the hedgehog is under extreme stress or if the hedgehog is poorly.

Hercules beetle

There are thirteen known species of Hercules beetle found in the jungles of South America and the Hercules beetle was named for it's sheer size as some males have been known to reach nearly 7 inches in length. Although it is quite rare for these beetles to get quite so big, the average adult Hercules beetle is usually between four and fifteen centimetres long depending on the species. The most distinctive feature of the Hercules beetle has to be the enormous horn-like pincers which protrude from the forehead of the males. These horns can grow longer than the Hercules beetle's body and are mainly used for solving disputes with other male Hercules beetles. Female Hercules beetles do not have horns but their bodies are thought to be larger, but shorter than their male counterparts.

Hermit Crab

The hermit crab has a soft under-body which it protects by carrying a shell on its back. The shell of the hermit crab is not its own, but one that belonged to another animal. As hermit crabs grow, they continue to find larger shells to accomodate their increasing size. Hermit crabs are omnivorous animals that eat pretty much anything they can find in the surrounding water. Small fish and invertebrates including worms, are the most common prey for the hermit crab along with plankton and other food particles in the water.

Blue Heron

The great blue heron found inhabiting parts of North America and as far west as the Galapagos Islands is the largest species of heron in the world and can measure nearly a meter in height. The smallest species of heron in the world is the green heron measuring less than 50 cm tall. The green heron is most commonly found in North America and Central America, and occasionally in Hawaii. All 64 different species of heron are very similar in body shape but not in size and colour. All herons have long pointed beaks which helps them to grab fish out of the water, along with long necks and thin, long legs both of which are useful to the heron as it lives it's waterside lifestyle. Herons also have enormous wings that can be nearly double the size of the heron's body.

Highland cattle

Highland cattle originally come from Scotland. Highland cattle can now be found in Europe, North America and Australia, where the highland cattle are all commonly farmed for their meat but some people also use the long hair of the highland cattle. Highland cattle have adapted to living in such harsh terrains as highland cattle have a large, strong build and a thick double layer of long orange hair. Highland cattle also have two horns on the tops of their heads which the highland cattle use to dig through thick snow to find the vegetation that lies underneath and the highland cattle also use their horns in order to defend themselves from oncoming predators and other rival highland cattle.


People have used milk for food from ancient times, and have developed certain animals to supply large amounts of milk. We depend on cows to supply most of our milk, but in Spain, for example, the sheep is one of the chief milk-producing animals.

Many desert tribes depend on the camel for milk, and in Egypt, they use water buffaloes. In Peru, the llama is a milk-producing animal. People in many countries use goat's milk.

Milk is the fluid secreted by the mammary glands of the animal are food for their young in the period immediately after birth. It takes the place of the blood which supplied the young with nutrition before it was born. In fact, it is exactly like blood, only without the red blood cells and the blood pigment.
The composition of milk varies quite a bit, depending on the species of the animal which produces it. But milk always contains fat, protein, carbohydrate, and minerals. Goat's milk, for instance, contains twice as much fat as cow's milk, and the milk of reindeer contains five times as much fat as cow's milk!
The milk of every animal also contains various salts according to the needs of its young. The more rapid the growth of the newborn, the more salts in the mother's milk. A cow doubles its original weight at birth in 47 days, but a human being does it in 180 days. That's why cow's milk is too rich in proteins and salts and must be diluted for feeding newborn children.

The milk produced by cows varies depending on many factors. One, of course, is the breed of cow and the constitution of the individual cow. Another is the time between milkings. The last milk to be drawn at each milking is richer in fat then the rest. So, if a cow has not been completely milked, it will probably have fatter milk next time.
Since green food is the main source of vitamins for the cow summer milk is usually richer than winter milk, when the cow can't walk about in the pasture. About 110 grams of food solids are contained in each litre of milk. The most important solids are the butterfat, the casein, the milk sugar, and the minerals.