Science and technology

•Invention-the act of creating or design something which did not exist before .For example:Invention of revolver by Samuel colt in USA around 1835.

•Discovery-the act of finding out or bringing to light or gaining knowledge of something,especially for the first time which already existed .For example:Discovery of Magnet by Magnes (a Shepherd) .

•Flying fish

The flying fish cannot fly like a bird,but it leaps into the air,up to 3m and then glides for about 200 m before splashing back .It usually does this only when frightened .

•Egg laying mammals

Bee-size baby

Platypus is a mammal,although it lays eggs .It grows up to 60 cm long ,lives in a burrow and hunts in the water .It is found in Australia .Only a few mammals lay eggs .

•Bee size baby

A new born kangaroo measures only about 2cm .It crawls into its mother’s pouch and stays there for six months,feeding on milk and growing .

•Musical insects

Insects have no voice .The noise they make are all produced by their wings or legs .The rapid movement of their wings or legs make that noise .Grasshoppers sings by rubbing their legs against a rough patch on their wings .Crickets use their wings to make sound .

•Unique pattern

No two zebras have exactly the same pattern of strips like human fingerprint ,each zebra’s stripe pattern is unique .

•Vampire’s dinner

Vampire bats are found in South America, feeds on blood .They laps blood by bitting asleep animals without disturbing them .The bat’s saliva contains a substance which stops the flow of blood from clotting .

•Great hunters

Although sharks have poor eyesight,but they have an excellent sense of smell .They can smell blood diluted a million times in water and thus can detect a wounded animal in the sea .All living animals produce a small amount of electricity .Sharks can sense this electricity and find where animals are hiding .

•Liver is the largest organ in our body,weighting about 1.6kg .

•Each day our heart beats normally over 1,00,000 times .

•The normal temperature of our body is 37°C or 98°F .

•There are 206 bones in our skeleton .A new born baby has 300 bones,out of which 94 bones join together as he or she grows .

•Most people have 12 pair of ribs .But one out of every 20 people has at least one pair extra .

•An average man has about 5.5 litres of blood .

•Each side of the brain controls the opposite side of the body .

•The hair on our head usually lives for 2-6 years before dropping out .

•The fastest muscles in our body are those that blink the eyelids .We can blink as fast as 200 times per minute .

•Our eyelids have the thinnest skin on our body (only 1 mm thick) while our soles have the thickest skin(about 3 mm thick) .

•It takes about 17 muscles to smile,but about 43 muscles to frown .

•The size and shape of a person’s nose can affect his or her voice .

•The coronary heart disease is the most common cause for sudden death .

•One brain cell may be connected to as many as 25,000 other brain cells .

•A meal takes as long as 15 hours to pass through our whole digestive system .

•Through blinking we spend about half an hour of our waking day with our eyes closed .

•The thigh bone,called femur,is the longest and the largest bone in our body .The smallest bone in our body is the stirrup bone in the middle ear .

The Electromagnet is artificial magnet or Electric magnet .It used to overcome the disadvantages of a permanent magnet because the electromagnet will produced electro magnetic forces till there is a supply of electricity(flow of electrons) it will lose its electromagnetism when there is a cut of electricity .

If we apply a nickel core in a electromagnet it will turn to a permanent magnet

Because of its gaining and losing of electromagnetic properties it gives a huge advantage like:use in cranes to transport metallic object made of iron,nickel,steel and cobalt .

History of electromagnet:

Electromagnet was invented by a British scientist “William sturgeon” in 1820’s .He discovered that electricity creates magnetism .

The Earth emerged from a swirling nebulae of interstellar gas and dust along with the Sun and other bodies in our Solar system .Countless tiny minerals grains collided with each other under the force of inherent gravity and condensed into larger planets like the Earth .

The Earth is the third planet from the sun with only one Moon and to support life form .The Earth looks like a spheroid but is flatter at its poles,making it an oblate spheroid, with an equatorial diameter of 12,756 km and a polar diameter of 12,714 km .It rotate once on its own axis, tilted at an angle of 23.5 degrees every 23hour,56minutes,and orbit around the Sun in an ellipse in 365days,6hours and 8minutes

Seasons and Earth-Sun Relations

The axial tilt of the Earth of 23.5 degrees as it moves around the Sun causes seasonal changes .When in June the northern hemisphere tilts towards the Sun,it gets maximum heat while the southern hemisphere gets little heat .In is thus summer is on the northern hemisphere and winter is in the southern hemisphere .Six months later,in December, the situation is reversed as the Earth travels halfway around the Sun and its northern hemisphere is tilted away from the sun .

On 21June,the Sun is directly overhead the head the tropic of cancer(23.5degrees north) and it it is in mid summer in the northern hemisphere .Mid summer in the southern hemisphere occurs on 22 December when the sun is directly overhead the tropic of Capricorn (23.5 degrees South) .

Our Solar system is located in the Orion arm(Local Arm) around two-thirds from the central bulge of the Milky Way,which turns once every 220 million years .The age of the solar system is 4.6 billion years .

The solar system comprises a central star,the Sun,and the bodies that orbit it .The bodies in the solar system include eight planets and their 61 known Moons,asteroids,meteoroids and comets as well as interplanetary gas and dust .

The solar system can be divided into an inner system of four small,solid planets which includes Mercury, Venus,Earth and Mars (these are also known as inner planets),and the outer system comprising the four much large planets Jupiter, Saturn, Uranus, Neptune (these are also known as outer planets), which consists of light materials .

The distance of planets from Sun: 

Mercury =58 million kilometers

Venus =108 million kilometers

Earth =150 million kilometers

Mars =228 million kilometers

Asteroid belt

Jupiter =778 million kilometers

Saturn =1427 million kilometers

Uranus =2871 million kilometers

Neptune =4499 million kilometers

Our galaxy is called the Milky way galaxy because it looks like a splash of milk in the sky .In the night,a faint band of light is visible in the northern sky .This dim light comes from nebulae and stars,The galaxy is vast measuring about about 100,000 light years across (1 light year is approximately 9,460 billion km) .Our galaxy is a spiral-shaped disc with a bulge at the center sending four arms spiralling outwards .

But if we compare the Milky way galaxy with the whole Universe it would be as we comparing our Earth to the Milky way galaxy .

Take a look at the website I made for nature maybe it will help you https://refreshingnature.jimdofree.com/

A galaxy is a huge mass of stars,nebulae, and interstellar dust and gases .Nebulae are clouds of dust and gases (mainly hydrogen and ionized hydrogen) that float in space .Often, the force of gravity pulls the particles of gas and dust closer into a swirling mass .If the mass is heavy enough,the spinning clouds will start to glow .This is a protostar, or first stage before a star is born

Stars are self-luminous bodies of hot and glowing gas(hydrogen) born inside the nebulae itself .Our Sun is a small star .Massive stars may have a mass of at least three times that of a Sun and some stars are massive as 50 times of Sun exist .Stars produce energy by nuclear fusion at the core .After millions or billions of years,when hydrogen starts running out,the core contracts while the outer portion continues expanding .The star is now called a red giant .The amount of mass a star has determines the rest of its life cycle .The core of low mass stars collapse,expelling the outer layers,which form a nebula .The core remains as a white dwarf and eventually cools to become a black dwarf .

A massive star will undergo a supernova explosion .If the remnants of the explosion is 1.4-3 times as massive as the Sun ,it will become a neutron star .After the explosion, a star with a core three times the Sun,will be swallowed by its own gravity .It now becomes a black hole which can readily attract any matter or energy that comes near it .