My Science School

 Elephants have many ways of communicating with each other. They use the trunk, the ears, the tail, body language and naturally their voices too.The way an elephant holds its trunk tells other elephants whether it is going to attack or defend itself. Elephants also touch and smell each other with their trunks to find out where the other elephant has just been, what it ate and how it feels. Elephants are capable of cornmunicating through their senses and through smells. They express joy and excitement by flapping their ears. The sound of ears beating on the skin is picked up by other elephants as a message to get in touch. The elephant’s tail is used to probesorroundings which they cannot see.Elephants can communicate with each other over great distances using their voices and hearing. Fellow elephants who know each other with quiet rumbling or purring which reminds one of a running diesel engine. Calves bellow loudly for their mothers when they feel lost. Anxious, attacking and attacked elephants  It is also known that elephant’s converse over great distances using infrasound which are low frequency sounds that human beings cannot hear. So, the next time you see an elephant standing frozen, with its head raised and ears sticking out, don’t disturb it…it is listening to a message that you cannot hear!

Experiments conducted by scientists seem to prove that dolphins do have a sort of language of their own. Dolphins appear to communicate with each other using an assortment of squeaks, whistles, and clicks. It is thought that they are warning each other of danger or if Food is nearby, but we are not yet certain exactly what they are saying. Some scientists have also discovered that dolphins can be trained to understand quite complicated commands given to them.

When a honeybee finds a big garden of flowers brimming with honey, how does it let its friends know about it? It hurries back to the hive, and does a little dance!Honey bees communicate with each other by dancing. The purpose of the dance is to alert other bees where nectar and pollen are located. The dance explains direction and distance to  The honey bee performs two types of dances...the round dance and the waggle dance. The round dance is performed for food sources close to the colony and the waggle dance used for food sources that are far Other bees attending these dances somehow-no one knows exactly how- learn the distance, direction, and odour of the flower patch. Once they have this information, they too fly directly to the flower patch in search of pollen and nectar

If you have seen a peacock spread out its feathers and dance, you will agree that it is a magnificent sight. But have you ever thought why it does this? The reason is quite simple… it wants to attract the female of its species which is known as a peahen! Dancing by the peacock is also an act to impress the peahen in front of him

Pheromones are chemicals released by living organisms to send messages to individuals of the same species. Pheromones play an important role in ensuring the reproduction of a species. They also serve to warn other members of the species of danger, to mark out territory, and to indicate food  When an ant is disturbed, it releases a pheromone that can be detected by other ants several centimetres away, causing them to run about as they work to remedy the Certain ants, as they return to the nest with food, lay down a trail of pheromone. This trail attracts and guides other ants to the   Some pheromones are deposited with the urine or faeces of an animal to mark its territory and warn away intruders. This is why you see dogs urinating on lamp posts!

 

    A phenomenon called polarity prevents oil and water from mixing. All molecules carry electrical charge which is distributed uniformly or non-uniformly over the length of the molecule. In polar compounds, the positive and negative charges are concentrated at the two ends of the molecule. When such substances are mixed together, the positive and negative regions of their molecules attract each other and as a result a clear solution is obtained. Water is a polar substance and mixes freely with other polar substances. Oil molecules, on the other hand, are non-polar. When polar and non-polar substances are mixed together, the mutual attraction of polar molecules separates out the non-polar molecules and the two substances do not mix.   

     The solubility of a substance depends on the nature of bonding in both the solute and the solvent. Salt is an ionic substance; that is, its atoms are held together by opposite electrical charges. Water molecule also has electrical charges – the hydrogen atoms are positively charged and the oxygen atom negatively charged. When salt is put in water the charges on the water molecule pull the oppositely charged atoms in salt apart, thus dissolving it. Oil molecules, on the other hand, do not carry any charge and so does not have any effect on the ionic bonds in salt when put in it. As a result, salt does not dissolve in oil.

                                    

            A knot in a lace is held together by the friction between the surfaces of the lace. Greater the friction more stable the knot will be. Since there is enough friction between cotton fibres in a lace made of cotton, it is quite easy to tie a knot. But silk being a smooth fibre, a knot tied with a silk lace becomes loose and opens up easily due to lack of friction between the fibres.

                                    

   Bubbles are balls of thin soap films. They show rainbow colours because the light falling on them undergoes what is known as interference. Light travels in the form of waves which have troughs and peaks at regular intervals. For instance, one wavelength of a light-wave has one trough and one peak. When light falls on a soap bubble it is reflected from both the upper and lower surfaces of the film. Thus, there are two waves of reflected light emerging out of surfaces of the soap bubble. If the distance between the two surfaces of the film is less than one wavelength of light, the two reflected waves are so close that interference occurs. The peaks of the two waves may add up and become a bigger peak. Or the trough of one wave may fall with the peak of the other thus cancelling its effect. As the seven component colours of white light have different wavelengths, the adding or cancelling effect of interference is not the same on all of them. In other words, some colours become brighter and some duller. Thus a viewer sees a mixture of rainbow colours instead of the white light emerge from the soap bubble.

                                    

  Unlike the steps in a staircase, a ladder has open rungs and is usually set at a steeper angle than a staircase. It is easier to maintain a firm grip on the narrow rungs of the ladder with one’s toes if one faces it. Also, when climbing down the ladder, a person tends to lean towards it to keep balance, which is easier to do if one faces it. On the other hand, the gentle slope of staircases and wide steps allow people to step down facing forward.

                                    

Most of the time, animals communicate with their own species. This is especially true of mating signals, since animals must be able to communicate with their own species to mate and reproduce. A male elephant seal, for example, will give a loud roar that tells female seals where to come ashore for breeding. Communication within the species is also important in the case of caring for the young. A mother gull must be able to recognize the calls of her own chicks so that she can find them in a thickly populated gull colony, and feed them.But communication also takes place between different species. This is especially true of species living in the same area. Recognizing the warnings given by another species can be very helpful in avoiding danger. In Africa, grazing animals pay close attention to the keen eared zebra. If a zebra suddenly starts running, the other animals know that an enemy is approaching, and will flee too.

Animals communicate with one another in different ways. The sounds made by an animal, its behaviour and the way it looks at another animal are three   important means of Taste and odour, electrical impulse and touch are also used to attract or drive away another animal. Sometimes an animal uses a combination of different mediums to get its messages across most effectively.

Smell is probably the most common basic means of animal communication. Even the most primitive animals react to odours given off by their own, or other species.Animals may use scents, to mark out territorial boundaries, to attract mates, to warn off intruders and predators or, in some cases, to attract prey. Animals of all kinds rely to a great extent on their hearing ability in order to succeed and survive, and this is called acoustic communication. Among mammals, generally speaking, small animals squeak, and large ones rumble. The acoustic communication signal most frequently heard by humans is, of course, bird song. The largest of all animals, the whales, appear to be experts in the art of communication by sound, with each whale of the same species having its own favourite ‘songs’ which it repeats at intervals.Visual signals may take the form of gestures and displays, facial grimaces, body posture or mimicry. Each species has its own way of using its facial expressions, body language, gestures and body markings to communicate effectively.At another level, animals may communicate a simple message through the art of mimicry. The markings on the wings of the peacock butterfly look like large eyes to frighten off its enemies. The same is true of the harmless hoverfly that resembles the wasp.

    Image is produced in a plane mirror by reflection. It is a virtual image, that is, it can only be seen in the mirror but cannot be projected on a screen like an image produced by a concave mirror or a lens. Every point on the virtual image corresponds to a point on the object in front of the mirror, but since the object and the image face each other we get the illusion of lateral inversion that is, the right side of the object appears to become left in the image. For the same reason, written or printed alphabets appear reverse when seen reflected in a mirror, except a few symmetrical alphabets such as M, O, W, T and Y.

                                    

When a monkey makes faces at you, do you know that it is trying to communicate with you? Visual communication may take the form of facial grimaces, gestures, body language, displays, and even markings on the  A peacock's extravagant display of feathers is a form of visual communication. The male rabbit will use the white underside of its tail to attract the attention of a female, while the female may use the white of her tail as a visual signal for her young to follow when she is leading them to the safety of the burrow.Dogs and wolves make use of body language, as do cats, monkeys and many other animals. The attitude of the tail when two wolves meet will indicate which of the two the superior is. Horses will hold their ears or tail in certain positions to signal pleasure or alarm.