What is air
. What we breathe is the Air. All life forms as well as plants need air to survive on Earth. Also known as Earths atmosphere, Air is made up of many gases like oxygen, carbon dioxide, nitrogen and in water forms such as water vapour.
Can we see air
. Air is a colourless gas; since majority of air is nitrogen which itself is a colourless gas. Nitrogen takes of about 78% of air; hence no colour is seen or reflected from air. But we can feel the presence of air as it moves leaves, trees or clothes in the direction of wind.
Why do we sweat
. Sweating is an important way of maintaining body temperature. When our body gets heated it releases moisture in the form of tiny water droplets, which cool the body as it evaporates. Sweating is a way of getting rid of waste material. There are eccrine glands which are under the arms and apocrine glands which are over the rest of the skin that release secretions. Our palms and soles have the maximum number of sweat glands.
How is the wind generated
. Wind is generated by the motion. Due to continuous sunlight in some parts of Earth, the air becomes warm. Warm air being lighter than cold air, it rises up and cold air takes its place. This movement of air causes generation of wind.
What is the color of light
. Many scientists have found out that light is a spectrum of many colors, hence there is no fixed color of light. Newton once displayed this with an experiment as he passed a beam of white light through a prism. The light split into seven colors which were Violet, Indigo, Blue, Green, Yellow, Orange, Red (or better known as VIBGYOR) just as it can be seen in a rainbow.
How is a rainbow formed
. A true marvel of nature, it is a wonderful arc of the spectrum of colors VIBGYOR. A rainbow is usually seen when sunlight passes through rain drops and is scattered into a band of colors. The light is reflected once from the back of the rain drop and then from the front, thus we see a curved rainbow.
What happens to water in the puddles
. We usually see that water disappears from the puddles. It is nothing but a phenomenon called as evaporation which is changing of the physical form of water from liquid to gas. The water evaporates and changes to water vapours which mix with air. This is similar to how we dry our wet clothes in the sun.
Why are slides slippery
. This is usually caused by a phenomenon called friction. If a surface is rough, it offers maximum friction and sliding will not be smooth. Hence slides are made slippery to reduce friction or resistance. Metal offers less resistance as compared to other materials.
How do magnets help in navigation
. Magnets have been used in the form of magnetised needle or compass that guides navigators and explorers to find their way when they travel. Earth has two magnetic fields with two poles - North and South Pole. The magnetic compass contains a needle which swings in the direction of North-South due to Earths magnetic field. The compass thus is an important tool for navigation due to Earths magnetic field.
Why do we see our image in the mirror
. Mirrors have clean and polished surfaces which reflect light completely when light falls on them. So when we stand in front of a mirror, the light reflected by us bounces back from the mirror and we see our image.
When we fall why do we fall down and not up
. The reason we always fall down is because of Earth's gravity, a force that pulls us down towards it centre. So whenever we fall, we always fall down and not fall up. Sir Isaac Newton discovered the phenomenon of Gravity as he was sitting under an apple tree and suddenly an apple fell down from the tree.
Why do sodas contain bubbles
. Sodas contain a gas called Carbon-dioxide. When this gas is mixed, high pressure gets created in the can as it is trapped in close space. So when you open the can, the trapped gas molecules escape creating fizz or bubbles.
Who was the first person to fly across the Atlantic Ocean
. On May 20, 1927, Charles A . Lindbergh became the first American Pilot who flew non stop across the Atlantic Ocean. His plane named ""The Spirit of St. Louis"" took off from, Roosevelt Field near New York City and set for Atlantic Ocean towards Ireland. It took about 34 hours when he finally landed to become the first person to cross Atlantic Ocean in a single flight. The first woman to cross the Atlantic Ocean was Ameila Earheart, a very popular
Can a car run on steam
. Many designs were made for development and experimentation of a steam engine used to power a car. Many attempts failed to make the car run at higher speeds as they became heavy as well. But the first usable steam car was built in 1899 in Conneticut. Among them the best selling car was "Stanley Steamer", built between 1896 to 1924. The car set a new World Speed record going at 127 miles per hour when tested in Florida in 1906.
What is an avalanche
. A snow avalanche is like any other natural force which we see in the form of earthquakes or tornadoes. When loose snow slides down a slope, it gathers more snow and becomes larger, wider and massive with greater speeds falling down. Avalanches with dry snow is very devastating as it half flies in the air as well.
What is the function of blood in human body
. The blood is responsible for carrying oxygen from lungs to various body tissues. Oxygen also controls the flow of nutrients, hormones and enzymes during metabolism. It also controls water content, regulates our body temperature and is responsible in blood clotting. Blood contains immunity building antibodies and white cells which prevent any diseases in the human body. Thus it is very vital for living.
What happens when we breathe
. When we take in air, our diaphragm expands which increases the space for our chest cavity so our lungs can take in maximum amount of air. This air reaches directly to our lungs. Our lungs contain air sacks called as alveoli which then diffuse oxygen from the air into our body by blood vessels called as capillaries.
Why do we yawn
. When we are tired, we yawn. In this case our breathing becomes much slower than normal rate and our body does not get sufficient oxygen. Our body then releases extra carbon dioxide to make up for the slow intake of oxygen.
Can we hear our heartbeat
. We can feel our heart beating all the time. Gently place your hand on the left side of your chest and feel your heart beating. We feel our heart beating more strongly when we are exercising, or nervous or under any extreme physical or mental condition.
Why do we have dreams
. According to scientists, when we sleep our brain creates a subconscious mix of things from its stored memories, emotions or moods. This weaves a dream of things or information which we hardly even recall or remember in our day to day life. Though dreams tend to be very fuzzy, and appear to have no ending or beginning, it is believed that they do hold some hidden meaning.
What is the work of our kidneys
. The kidneys in our body cleanse the bloodstream and maintain the chemical balance in the body. After the process of digestion is completed, the waste mixes in the bloodstream. Kidneys filter this blood and the waste and excess water is thrown in bladder. The waste is removed through human body in the form of urine.
How are seeds made
. During fertilization, the deposited pollen on the female flower moves below the flower and into the top most part of stem. Here after successful mixing of male and female DNA, the pollen ripens and develops into a fruit which contain seeds. Thus a seed is developed which inturn has an embryo and an outer covering.
What makes us sneeze
. The air we breathe is usually a mixture of many substances which need to be avoided by our nose. Our nose senses this and expels unwanted particles through the nostrils be it dust or pungent smell. Many people are very sensitive and react strongly when they smell substances like paints or perfumes. This makes them sneeze.
What makes us shed tears
. Our eyes have tear or lacrimal glands located at the outer corner of our eye behind the upper eyelid. When we blink, a salty solution is released that washes the eyes and is drained into the tear duct in the corner of the eye. It has been observed that during happiness or sadness, there is excess blood flows to the face or increased pressure and the upper eyelid squeezes the lacrimal gland. When these causes excessive build up, it comes out in t
When was the first farming done
. According to Archaeologists, farming was not a mainstream activity till 13,000 years ago. Farming soon emerged as a livelihood later in different parts of the world, starting in Asia then in some parts of Africa, Mexico and America.
What were the weapons used by man in prehistoric times
. In prehistoric times, our ancestors used to make tools from stone. Gradually man started to make stone tools by removing flakes and blades from a stone. Bones and horns became a common tool later, along with other weapons such as the bow and arrow or spear. Man later evolved and started using metals such as bronze and iron.
How did we gather information about our ancestors
. Researchers and scientists gather information about pre-historic life by studying remains of plants, animals and other objects, their fossil imprints and human bones. According to scientists, the study of human evolution consisted of apes which evolved into three distinct categories. One of the species was of humans, whle other two were of gorillas and chimpanzees. Much information is derived from the drawings and inscriptions on the wall.
Who were the most ancient Greek Philosophers
. Among many famous scholars, mathematicians, rulers, poets, Alexander the Great is considered to be one of the most greatest military rulers. Aristotle and Plato contributed hugely in life and ethics. Meanwhile Archimedes, the astrologer became a pioneer in the field of science and mathematics. Thus Greece has been a homeland to some of the most brilliant people in the history of time.
Why did Pharaohs need pyramids
. Pharaohs were Egyptian kings who wanted the construction of pyramids as places of burial. In fear that their dead remains would be robbed, thus enclosed structures known as pyramids came into existence.
What was the venue for the first Olympics
. The first Olympics were held in the early 700 BC in Greece. To commemorate the occasion, an ivory and bronze statue of Zeus was built. The first modern Olympics were held in Athens in 1896 and the winners were crowned with a wreath made of olive and tree branches.
What is the Asteroid Belt
. The region between the inner planets and outer planets is covered by thousands of asteroids orbiting around the sun. This region came to be known as the Asteroid Belt. The belt between Mars and Jupiter is known as the Main Asteroid Belt.
What is the Sun made up of
. The sun is entirely made up of two gases called hydrogen and helium which are also the lightest elements in the universe. The sun is mostly made up of hydrogen which occupies 72 percent of the Sun's mass whereas helium consists of the remaining 26 percent followed by other elements.
How does the moon shine
. The moon shines bright because it reflects the light which reaches it from the sun. Even though moon reflects only 7 percent of Sun's light it glows slowly but not as bright as the sun.
How can we use the Sun s energy
. Sun's energy can be harnessed in many ways. People are moving towards natural sources of energy such as Solar Energy which causes zero pollution. This solar energy due to its heat can be used for heating purposes. Hence solar cookers and water heaters apply the same principle. Solar cells are available nowadays which trap sun's light and convert this into electric energy.
What is a Galaxy
. A galaxy is nothing but a collection of stars, dust and gases. This group of stars and gases are held together in a disc-like manner because of a gravitational force. It is believed that it would take a few hundreds of light years to cross a single galaxy.
What are Constellations
. A group of stars situated closely to each other form what is known as a constellation. These constellations are defined as patterns formed by prominent stars known to us. A few common constellations are Ursa Major and Ursa Minor. Orion the hunter is also a famous constellation.
What is Astronomy
. Astronomy is the branch of science which studies celestial bodies, like planets, stars, constellations that lie around the Earth's atmosphere. The world's oldest civilisations made use of astronomy to predict the future. Today, astronomy is hugely linked with physics as scientists study various aspects of the Universe such as for communication and other purposes.
Why do Astronauts use space suits
. Astronauts wear space suits whenever they leave a spacecraft as they become exposed to very low temperatures and high levels of radiation. Since there is no air in space, the suits provide breathing are equipped with an attached apparatus. Thus this suit is essential for an astronaut otherwise he would freeze due to cold in gravity less space.
Who was the first person to land on the Moon
. 28th July 1969 was an important day in the history of mankind as Neil Armstrong (left) set foot on moon and became the first person to walk on its surface. Accompanied by Michael Collins (center) and Buzz Aldrin (right) in Apollo 11 spacecraft, Neil Armstrong said, "its one small step for man, one giant leap for mankind."
Which weapons were used by the Roman soldiers
. The Roman Army was well trained to fight and defend themselves. They used swords, daggers and carried a long spear. They often wore shields and helmets for their safety.
Which was the biggest ever land animal
. The biggest ever land animal was a dinosaur which belonged to the Sauropod family. Scientists have named it Amphicoelias fragillimus. This discovery was made by scientists who found the dinosaur's incomplete fossil.
Where did dinosaurs live
. According to research, dinosaurs were present on all continents. But since very little information can be obtained from fossil data, nothing much can be said about them. Though traces of plants and animals have been found but it stil remains unclear.
What happened to the dinosaurs
. During the last years of the Cretaceous Period, Earth became much cooler and drier. The dinosaurs could not adapt themselves to this environmental changes and became extinct. Many volcanic eruptions and asteroid attacks were also responsible for the climatic shift which also lead to the extinction of dinosaurs.
Which planet was found by an accident
. Sir William Herschel accidentally discovered Uranus in 1791. Many astronomers had noticed this planet but misunderstood it to be a star. Sir William noticed that one star was different from the others and seemed much farther away from the Sun and Earth. The star was later named as Uranus.
Why is sea water salty
. The combined presence of minerals salts, chemicals and dead remains of marine animals makes the water salty. Most of these minerals come from rivers and streams that add water to the sea, rainfalls, weathering of rocks below the sea. Also during evaporation process, pure water is evaporated from the sea and concentrated salt water is left behind. Thus the water remains salty.
How much high are waterfalls
. Every waterfall has a different height. Angel Falls located in Venezuela is 3,212 feet high and is the highest waterfall in the world. In contrast, this is higher than two Empire State Building or the Burj Khalifa Towers. Its fall has a drop of 2,648 feet. Other notable waterfalls include the Waihilau Falls in Hawaii which is 2,600 feet high.
How are islands made
. Islands are usually of two types - continental and oceanic islands. Continental islands are basically extensions of a continent that remain connected underwater along parent continent's coastline. Whereas Oceanic islands are formed when a volcanic activity or other disturbances take place on the ocean floor. These islands are thus pushed out of the ocean floor. United Kingdom and Japan are examples of continental islands whereas Hawaii is an ocea
Which is the biggest ocean
. The Pacific Ocean is the biggest ocean with an area of 165.2 million square kilometres and occupies about 33 percent of Earth's surface area. The pacific ocean is larger than all the land areas put together. The ocean covers from America to Asia and to Australia from the other side.
Which plants are found in seawater
. A variety of sea grasses are found in sea water. These are rooted in the sandy sea beds and even bear flowers and cover wide expanses like a meadow. The plants have long and narrow leaves which are green. Since they need sunlight for photosynthesis, this grass is commonly found in lighted or photic sea zones or around the shallow and protected coastal waters. The plants add oxygen to the air and protect the shoreline from being eroded.
Can Animals survive on the Arctic Circle
. Yes, animals and wildlife do survive on the Arctic as these animals have adapted themselves to the extremely cold weather. Arctic foxes, polar bears all have a thick furry coat which keeps them warm. Even walruses and whales can also be found here. The sea animals contain a thick layer of fat under their skin called blubber to keep them warm. Other fish also survive in this cold due to a protein present which prevents the blood from freezing.