Why Are Some People Left Handers?

Why Are Some People Left  Handed? Interesting Facts About Left Handers

                                      


According to one estimate,10% of population are left handed. According to yet another estimate, two out of three lefties are males. 84% of left handers have both parents right handed. And in 12% genetically identical twins, the one will be right handed and the other left.

Two out of three lefties are males. Left handedness is hereditary. About 50% of the children of lefthanded parents will be lefthanders. Left handers outnumber among the members of certain families.



In 90% of the right handers the speech language sender is in the left hemisphere of the brain, while only 15% of left handers have it on the right hemisphere.

Left handers are at high risk of psychological problems and victims of schizophrenia, phobias, and maniac depressions. They are also three times more likely to attempt suicide. Left handers are also twice as prone to diabetes, ulcerative colitis, arthritis ,etc.

About twenty percent of mathematical geniuses are left handers. Among the histories most famous warriors were many left handers. They include Alexander the great, Julius ceaser, Charlemagne ,Joan Of Arc, Nepoleun, and others. Michelangelo , Leonardo Davinci, Charle Chaplin, Marylin Munroe, George Bush, Bill Kilnton and several other notable personalities belong to the left handed group.

According to scientist the handedness of the human beings is related to the structural patterns of the nervous systems and its relationship to the brain.

Read More

Why Does Venus Rotate Backwards?

Cause For The Abnormal Reverse Rotation Of Venus

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows. Because Venus is an inferior planet from Earth, it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it has been referred to by ancient cultures as the Morning Star or Evening Star.



The movement of a planet about an imaginary axis is called rotation. If we imagine ourselves to be looking down upon the north pole of the earth, the direction of its turning will be in counter-clockwise. If we place a finger upon a point on a globe near the equator and push the finger eastward, it will give the correct rotation. Of the Eight planets of the solar system, Venus rotates backwards. That is , while earth and the other planets rotate from west to east, Venus rotates from east to west. 
This backward rotation is called 'Retrograde Rotation'. The rotation of this planet is at a slow rate. With respect to the stars Venus completes one rotation in 243 days but it needs only 225 earth days to revolve round the sun once. Venus is the only planet that takes more time for rotation than for its revolution. However scientists haven't yet discovered the scientific reason for this peculiarity.

Read More

How Does A Mongoose Defeat The Snake?

Is The Mongoose Really Immune To Snake Venom?

Every time you talk about mongoose, you talk about snakes also. In ancient Indian medical books, mongoose is called "Sarpa-vaidhya" ( Snake Doctor). In ancient Egypt mongoose was worshiped. Aristotle noted that mongooses acquired an artificial armor by rolling in water and dirt or mud and drying their coat before attacking a snake. In India a popular belief prevailing is that mongooses use a herb to overcome deadly effects of snake poison.

            
                     Mongoose is a small short legged carnivorous animal. It is an expert in fighting. In the fight with snakes, the mongoose employs various tactics. It turns swiftly away from the snake who is about to bite. The mongoose is capable of lifting up the hairs in its body. This helps the mongoose to look bigger than its size. Besides, the snake cannot bite through the fur. 

                     They attack and kill poisonous snake. They depend on speed and agility, darting upon the head of the snake and cracking the skull with a powerful bite. They aren't immune to venom,  as popularly believed, nor do they seek and eat a herbal remedy if bitten.
           
                      The mongoose will have pounced on the snake before it raises its hood after one futile strike. Mongoose can kill and eat even very poisonous snake.

Read More

Why do we sleep?

Why do we spend quarter of a day sleeping?

                                     


Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than being in hibernation or a coma. Sleep is a heightened anabolic state, accentuating the growth and rejuvenation of the immune, nervous, skeletal and muscular systems. It is observed in all mammals, all birds, and many reptiles, amphibians, and fish.

We feel sleepy when we are tired after work.At night we feel sleepy.Why does one feel sleepy? It is the rest acquired through sleep that makes us energetic.Sleep is essential to remove fatigue and to maintain health .                                                                          
               Numerous  studies are being done on sleep.Then brain controls all the functions of the body.It has been concluded that the part called cerebellum in the brain controls sleep.When we work for the whole day,the quantity of calcium increases in our blood.Sleep is essential to reduce the quantity of calcium.It is the brain which gives the instruction to sleep.

                  When calcium was directly injected into the brain of animals,they soon fell down sleeping but when calcium was injected into the blood they didn't sleep.Thus,it has been concluded that it is not only the quantity of calcium but something else is also the cause of sleep.Research is progressing.Let us wait for the progress.              

Read More

Why acids cause burns on skin?

Why Burns Occur When Acids Falls On Our Skin?

An acid is a substance which reacts with a base. The word acid is derived from Latin Acidus meaning sour.  Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH under 7, with acidity increasing the lower the pH. Chemicals or substances having the property of an acid are said to be acidic.

Strong acids like sulfuric acid, nitric acid, hydrochloric acid are very reactive and cause intense burns on our skin.Acid can absorb water and bring about a high temperature.All living cell contain water.Acid that falls on the skin absorbs this water and produces heat,thus causing burns.

                                                            

The first aid for an acid burn is to keep the affected part under water.Then you have to wash the burnt areas with a solution of ammonia.This alkaline solution will neutralize the acid.

                                                                    However,not all acids are dangerous.Since acids are dangerous to living things,they used as preservatives to kill bacteria.Vinegar is widely used for pickle making.this acid is weak acid.

Read More

Why helicopters have a tail rotor?

Why Does A Helicopter Have A Second Rotor On Its Tail?

 We all know or seen helicopters. Such a marvel of human engineering. It is also called as a chopper, helo or whirlybird.It is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would usually not be able to take off or land. The capability to efficiently hover for extended periods of time allows a helicopter to accomplish tasks that fixed-wing aircraft and other forms of vertical takeoff and landing aircraft cannot perform.

Well the obvious question arises now. Why does it require a tail rotor?

Its simple, to counteract the torque effect caused by main rotor.
Lets make it clear. When the helicopter is working, the big main blade rotates and causes the lift necessary to rise up. But as it moves up, there isn't any contact with a stationary object as ground any more. Still the main blade is rotating with great velocity. Since there are no external forces acting on the system, the angular momentum of the system remains constant. Hence the angular momentum of the main blade has to be balanced/canceled, if not the helicopter will find its own way to do that-The helicopter will rotate in a direction opposite to the direction of rotation of main blade.

The speed of rotation will depend upon the moment of inertia of the copter. This causes the pilot to pop! Humans found a way to avoid this - attach a tail rotor such that it will provide the angular momentum necessary for balancing the chopper. It is clearly explained in the picture above.

Hope you have understood why it is needed...


Reference
1. Angular Momentum- Momentum equivalent in rotation. Product of angular velocity and Moment of inertia.
2. Torque-The rotating action of a force .

Read More