My Science School

            During the 1st century AD, a Greek inventor and mathematician called Hero of Alexandria produced a device that later led to the development of modern turbines and jet engines. Hero’s device was a hollow water-filled ball mounted on a swivel. Two nozzles stuck out on opposite sides, pointing in different directions. When the ball was heated, steam shot out of the nozzles, causing the ball to spin rapidly.

            Hero failed to see the practical use of this device and regarded it as an interesting toy. He went on to invent several mathematical formulae, one of which is still used for calculating the area of a triangle.

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                         Marie Curie and her husband Pierre began their research into radioactivity in 1895. They soon discovered the new element thorium, and in 1898 they discovered two other elements — polonium and radium. They received the Nobel Prize for physics for this work in 1903, although they shared the prize with Henri Becquerel, who researched the same subject. After her husband’s death, Marie continued her research, winning a second Nobel Prize before dying in 1934 of cancer caused by unprotected exposure to atomic radiation. A new element discovered in 1944 was named curium in her honour.

   

                      Albert Einstein (1879-1955) was a physicist who was born in Germany but lived in Switzerland and the USA in later life. He developed the theory of relativity, which led to the famous equation E = (which very few people actually understand).

                     Einstein’s work is the basis for most of our theories about the nature, history and structure of the Universe. He laid down the rules that govern objects moving close to the speed of light, and explained why travel at this sort of speed could distort time itself. His work also proved invaluable in the development of the atomic bomb.

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                              Luigi Galvani (1737-1798) was an Italian scientist. He accidentally noticed that severed frogs’ legs twitched when the nerve was touched with a pair of metal scissors during a thunderstorm. Alessandro Volta (after whom the volt is named) explained why this happened. It was because an electrical current was produced between two metals, which provided the stimulation to the nerves. This discovery later led to the realization that the nervous system works by means of electrical signals.

 

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                    The scientists James Watson and Francis Crick studied genes in an attempt to find out about their structure. The genetic material DNA (deoxyribonucleic acid) is a complicated molecule, and it had been difficult to understand how DNA could copy itself when cells reproduce. Watson and Crick found that it was shaped like a stepladder twisted into a spiral, and that if the two sides were pulled apart the ‘rungs’ of the ladder would automatically reproduce the rest of the molecule.

 

                      Ben Franklin (1706-1790) was an American with many talents. He was a printer, scientist and politician who played an important part in founding the United States. He discovered the nature of lightning while flying a kite during a thunderstorm. Franklin noticed sparks jumping from a key tied to the end of the wet string. This could easily have killed him, but it did not. He went on to invent the lightning conductor, a strip of copper that is run from the top of a building to the ground in order that lightning can earth itself safely.

 

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                   Archimedes was a Greek mathematician who lived between about 287 and 212BC. Unlike many Greek philosophers of the time, Archimedes believed in making experiments to prove that his theories worked. He made practical inventions, such as the Archimedean screw which is still used today to lift water for irrigation. He also worked out the laws which govern the use of levers and pulleys.

                Archimedes is most famous for allegedly leaping out of his bath in excitement shouting ‘Eureka!’ (The Greek for ‘I have found it!’). He did this when he realized that his body displaced a volume of water equal to its own volume.

 

                Galileo Galilei (1564-1642) built several telescopes and observed the movements of the Moon and planets. He was the first person to discover that the surface of the Moon is rough and cratered, and not smooth as had been supposed for centuries. He also found that he could use the swing of a pendulum to measure time.

               Galileo got into trouble with the authorities when he claimed that the Earth moved around the Sun, rather than the Sun moving around the Earth. This idea was thought to be a threat to biblical teaching, and Galileo was placed under house arrest for the remainder of his life.

                         Most modern photocopiers use a process called xerography, which was invented back in 1937. Photocopiers contain a drum, which is coated with a photosensitive substance. It only conducts electricity when light falls on it. The drum is charged with static electricity. An image of the document to be copied is focused onto the drum. Where it strikes the drum’s surface, the static electrical charge is removed, leaving an electrostatic image of the document. The drum is then coated with black toner powder, which sticks to the charged areas. It transfers the powder to a sheet of paper, which is heated to make the impression permanent. Some older types of copier use a ‘wet’ process. These machines are used to make large prints of engineering drawings.

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                      Natural gas is widely used to supply energy for domestic use and for industrial processes. It was formed millions of years ago by the same process that produced oil. Gas flows or is pumped out of boreholes, often mixed with oil and water. The gas is separated and passes through a refinery. Some of its constituents, such as propane and butane, are removed and liquefied so they can be pumped into cylinders and used as fuel. Liquefied gases held under pressure can be carried all around the world in specially constructed ships.

                       The remaining gas, which consists mostly of methane, is pumped along pipelines for domestic use. Methane has no smell, so a strong-smelling additive is used to make people aware of gas leaks.

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                 Most powered devices in the home contain an electric motor, which turns electric energy into movement. When an electric current passes along a wire in the field of a magnet, it exerts a force to move the wire. Usually the magnet is still, while the coil carrying the current spins round inside it. Domestic motors run on alternating current, and the current in the coil is rapidly reversed so the magnet’s poles change direction too, forcing the coil to make another half-turn. This process is repeated very rapidly as the motor turns.

                 When a motor runs from direct current, which flows in only one direction, a device called a commutator reverses the current and causes the coil to rotate.

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                 Electricity is generated by burning gas, coal or oil, by water or hydroelectric power, or by nuclear power. The distribution of power to homes varies in different countries, but in Britain the voltage from the power station is between 100,000 and 400,000 volts. The electricity is carried on cables strung between high pylons, where insulators prevent it from escaping to the ground. The cables are connected across the country in a system called the National Grid. If there is a fault with one power station, power can still be obtained from the grid.

                The electricity is drawn off in substations, which reduce it to 240 volts. This voltage is used through most of Europe, while in North America 120 volts are used.

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                      The huge quantities of domestic and industrial waste that we produce cause a major environmental problem. Sometimes waste is buried in vast landfill sites, which are often old quarries. Alternatively,  waste can be burned or in some cases recycled.

                      Waste from our toilets, baths and washing machines is collected in sewers and carried to a treatment plant. Bacterial action breaks down solid waste into a harmless form, and the waste is stirred in huge pools while this process takes place. After treatment, purified water is run off and can safely be drained into rivers. The solid material remaining is usually processed into fertilizer, after further treatment to make sure it contains no dangerous microbes.

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               An adequate supply of clean water is essential for life and for health. Water is often drawn from rivers, or may be pumped up out of the ground. Rainwater soaks into the ground and collects in areas where an impervious rocky layer stops the water from draining away. Wells are bored down into this layer to extract the water. A huge mass of fresh water in porous rock beneath the Sahara desert could supply all the water needs of North Africa for hundreds of years. Water from wells is usually stored in reservoirs. Before being used it is purified. The water goes to a settling tank where mud and sediment are removed. Chlorine is added to kill any microbes.

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                        Livermorium, the element number 116, is named after the Lawrence Livermore National Laboratory in California. The element was first synthesized by the scientists of JINR, Dubna, in 2000. The name was officially given by the International Union of Pure and Applied Chemistry on May 23rd, 2012. An extremely radioactive element, Livermorium can be produced only artificially; and therefore, little is known about it. The element is represented as Lv.

 

 

                     Tennessine is a radioactive element. It is artificially produced in a lab. Since the element is not found naturally in the universe, nothing much is known about it. The element is expected to be a solid, but its classification is unknown. In November 2016, the International Union of Pure and Applied Chemistry (IUPAC) approved the name tennessine for element 117, after the American state, Tennessee. The element is represented as Ts.

 

 

 

 

                       Oganesson is a radioactive, artificially produced element about which little is known. It is expected to be a gas. The atomic number of oganesson is 118, and the symbol is Og.