Category Science

Do snakes love music?

               All of us have seen snake charmers playing their pipes before a snake. When a snake charmer plays his pipe, swinging it backwards and forwards or jerking up and down, the cobra raises its head and moves in rhythm with the music. There are many folklore about snake’s love of music. Some snake charmers even claim that they can summon snakes by playing on the pipe. Do snakes really love music?

               The snakes do not have an auditory structure. They have a bony rod called columella auris. This bone extends from the fenestra oxalis to the quadrate bone. This bone has a special structure which helps it to detect the ground vibrations. But it cannot detect vibrations in the air. Due to this a snake detects an approaching ball.

               In order to verify whether snakes can detect the vibrations produced in the air or on the ground, a number of experiments have been conducted with different species of snakes by P.J. Deoras at the Haffkins Institute, Bombay. He put a snake inside a tin box and studied the effect of soft music near the tin box. He found that any sound that caused the tin to vibrate made the cobra to raise its head. He took a snake charmer inside his snake farm and found no response for air borne music. However, it responded to ground music.

               Experiments on five other species were also conducted. And again the findings were that the snakes did not respond air-borne music. However, they responded to the music of drum which creates vibrations in the box or earth.

               In short, it can be said that snakes are very sensitive to sounds that create vibration on the ground. Because of this fact, the snake charmer hits his pipe with the ground to make the vibrations reach the snake. A snake charmer also hits the snake with the pipe and tries to excite him. Actually it moves its body only to keep an eye on the moving pipe.

 

Why do trees change colour in autumn?

               On the basis of autumn defoliation (shedding of leaves) trees and plants can be divided into two groups. The first includes those plants and trees which undergo defoliation every year and are called deciduous trees, while the other includes the evergreen plants or trees which defoliate very slowly and remain green throughout the year. Evergreen plants also undergo defoliation but at one time only a small portion of their leaves fall off.

               Every year with the approach of autumn the trees begin to have their period of rest. In autumn the leaves fall and eventually rot down to give the leaf-mould and humus, which are essential to support rich vegetation. During this period gradually their leaves turn yellow and then curl up and fall on the ground. The tree then remains almost completely inactive until the arrival of spring. The denuded or defoliated trees or plants are a sad sight but at the same time very useful to plants because after it plants get a new life and look. Before defoliation the leaves take yellowish, brownish and reddish hues.

               But why do the trees shed leaves? We know that plants are living organisms which need food to survive. This food is obtained by utilizing the organic substances provided by the leaves. Just like animals, plants also produce waste materials and have to get rid of them, but they do it in a different way. They have to retain waste materials in their tissues until autumn. When the time comes for trees to shed their leaves, the plants extract all the useful products from them, and shake off the waste materials behind. Due to the presence of these waste materials the leaves turn yellow, brown and red. When the leaves are shed a layer of dry needles is left on the tree and it is visible in winter.

               Autumn is thus the period in which the trees get rid of their waste materials.

 

Why do animals have a tail?

            All vertebrates except man have a tail. According to scientists, there was a time when man also had a tail. But when he stopped using it, it fell into disuse and became extinct. We still have a mark of a tail on our body. Do you know what the usefulness of a tail in different animals is?

            The tail is found in the post-anal part of the body. It has different uses in different animals. In fishes it is surrounded by a tail fin and plays an important part in providing forward thrust. They have different types of tails. These help them in swimming and providing the upward movement.

            In crocodiles and whales the tail acts as a powerful organ for locomotion. In frogs and toads the tail and tail-fin are present only in the larval states and absent in the adult. Crocodiles use their tails for defence and also to attack their enemies. 

               All reptiles possess a well-developed tail. The length of these tails is different in different reptiles. Tortoises and turtles have short tails while lizards have long ones. If somebody attacks a lizard, it can break a part of its tail. It is a defence mechanism. Reptiles perform wriggling movements with the help of their tails. Lizards after sometime regenerate a new tail. In chameleon the tail is quite long. It can be rolled downwards to coil round the branches for extra grip. The tail of snake is small in size. It acts as a storehouse of fat. The tail of the sea snake is small in size and oar-shaped, and helps it in swimming.

               Real tail in birds is extremely short and stumpy. It gives a support for the feathers. Feathers help birds in flying.

               Most mammals have well developed tails. With these they can get rid of flies. Men and apes do not have such tails. Whales have two lobes of tail fin of which one is at right and one, at left. It helps it in swimming. The tails of kangaroos and squirrels act as a balancing organ during walk and leap. During winter season when squirrels hibernate, the hairy tail acts as a blanket. Rabbits use their tails for providing warning signals. Peacocks display their tails to attract the opposite sex. In this way we see that different vertebrates make use of their tails for some purpose or the other.

 

Does our body generate electricity?

          We all have heard of fishes producing electric currents but it is surprising to learn that our body itself generates electric current. Not only electricity but even magnetic impulses emanate from our body organs. The electric current generated in our body helps in controlling and working of the nerves and muscles of our body. In fact, electricity is consumed in some form in all the activities and functions of our body.

          The power of muscles in itself is a product of attraction and repulsion of electric charges. The functions of the brain are electrical in nature. All messages received and sent by the brain are transmitted by tissues in the form of electric impulses. For performing some special kind of functions many electric signals are produced. These electric signals are produced by electro-chemical actions in special kind of cells.

          Many physical disorders can be detected by measuring these electric signals. For example, any irregularities in the functioning of the heart can be detected by the electric signals of the heart. In the same way, electric signals generated by muscles, brain, eyes etc can be recorded and on its basis the malfunctioning of any of these organs can be known.

          Electromyogram is used for recording electric signals of muscles. For recording electric signals for heart and brain, the electrocardiogram and electro-encephalogram are used respectively. For magnetic signals of the heart, electro-magneto cardiogram is used.

          Specialists in different diseases can find out various physical ailments by analyzing these electric signals. Proper treatment can be given after diagnosing the disease. Information obtained from these electric signals is very important for the doctors in suggesting treatment for various diseases.

 

How is vision tested?

               When we see an object the light falls on the light-sensitive cells that form the retina. These send nerve impulses to the brain which ‘sees’ the picture or an image that is formed at the back of the eye. This is how we see the object.

               The lens of our eye is very soft and its shape is altered by the ciliary muscle. These muscles control focussing in the eye and this alters the shape of the lens. Some people cannot focus on distant objects and some other on nearby things. In such cases the object appears blurred and we say that eye has a defect of sight.

               For testing the eyes, the eye specialist makes use of a chart in which different letters in different sizes are written. Below these is written 6/36, 6/24, 6/18, 6/12, 6/ 9, 6/6 and 6/5 etc. Specialists ask the person under test to read the different letters or numbers on the chart and upto the row the patient reads the chart is marked as his eyesight. All these letters have a common digit of six. This indicates that this chart should be placed at a distance of 6 m or 20ft from the eye. If a person’s eyesight is 6/12, it shows that this man can read this letter from a distance of 6m while a man of normal sight can read it from a distance of 12 metres.

               In this way the eye specialist tests the sight and prescribes a number. For example if a person has a number -2D, it indicates that he cannot see the distant objects clearly and he needs a concave lens for his spectacles that brings light rays together. Similarly if the number is in plus sign, he cannot see nearby objects clearly and needs a convex lens that diverge light rays before they can enter the eye. The letter ‘D’ stands for dioptre which is the unit of power of a lens. Two dioptre mean a lens of 50 cm focal length.

               If a person is not able to see clearly both the near and distant objects, he needs spectacles of compound lenses. If someone delays the use of spectacles his sight may further deteriorate. In modern techniques, computers are used to ascertain the unit of power needed for individual patients.

 

What is ecology?

          Our lifecycle is closely related to ecology. Austrian geologist Eduard Suess first studied this relationship nearly a century ago. The word “ecology”, however, was derived from the Greek words “Oikos” meaning the house and logos meaning study.

          Now the question arises what actually “ecology” means? Ecology is the study of animals and plants in their natural surroundings or environments and how each species fits into its ecosystem. An ecosystem is a community of plants and animals spreading over a certain area together with the soil and other non-living materials. Therefore, the whole earth can be considered as a large ecological unit. Within an ecosystem, the organisms make up the balance with the environments.

          We all know that the most important factor for any organism is its source of energy or food. Thus within any such system a complex pattern of feeding relationship which we call food-chain, is built up to maintain the ecological balance. For instance, plants are a primary source of food and energy — the herbivores obtain their foods by eating plants. In their turn, herbivores are played upon by carnivores, which may also be a source of food for other carnivores.

          A typical example of an ecosystem is a pond, a desert or a forest. Within such an area are the major factors determining the type of ecological system that develops? In any ecological system, each organism however large or small plays a vital role in maintaining the stability of the community. Within this system carbon, nitrogen, oxygen and hydrogen (in water) are continually being recycled, through a number of processes. These are known as Carbon cycle, Nitrogen cycle and Photosynthesis.

          Over millions of years nature has moved towards the overall creation of a stable ecological balance. Natural changes such as adaption to the slow-changes tend to be gradual. But man is often responsible for causing sudden ecological imbalances through activities like deforestation; polluting the atmosphere, rivers, lakes and seas; by rapid industrialization or sometimes through the outbreak of a new disease. The effects of such types of change can be fast and irreversible. Upto now these changes have not been too serious except in some areas like disturbances of carbon cycle in the atmosphere. This is seen as a serious threat that may lead to the Global warming to change the ecology and thus an impending danger to the humanity all over the world.

          However, there is an increasing awareness of what could happen if a worldwide disturbance in ecological balance could not be checked in time.