My Science School

The television was not ‘invented’ at one particular time by one particular person. The processes which enable a television to operate were developed over a period of time.

In 1875, G.R. Carey made the first basic television system using photoelectric cells. An object was focused through a lens onto a bank of photoelectric cells. Each cell controlled how much electricity would be passed on to a light bulb. Crude outlines of the object then appeared in lights.

1923 brought the first practical transmission of pictures over wires. There was also a great development in television camera technology.

By 1945 the television as we know it today had been developed.

Continuous technological developments have meant that the quality of television pictures has improved dramatically.

Fact File With the use of communication satellites, TV programmes can be beamed to the most remote parts of the world, including the Amazon jungle!

 

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Morse code is a messaging system which uses two kinds of signal, a short one called a dot, and a long one called a dash. The signals are sent via telegraphs. A transmitter sends a coded message in long and short bursts of radio waves along a wire; the receiver then translates the dots and dashes into their representative letters, numbers and words.

Samuel Morse (1791-1872) was an American engineer who developed this system. He conceived communication via telegraph in 1832. After several years of work on the idea, Morse perfected it in 1838.

However, at that time, telegraph lines did not exist across land, so there was no way Morse could put his code to use on a practical scale.

It was 1843 before the US government allocated a sum of money to construct a telegraph line between Washington and Baltimore. Morse sent the first Morse code message along the lines in 1844.

Fact File Morse code was used a lot during World War I because it was a quick and easy way of sending messages. Probably the most famous signal was SOS which actually stood for ‘Save our Souls’.

 

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The very first ‘matches’ were designed by early man when he had discovered fire. Rubbing two pieces of flint together to create a spark with which to ignite dry leaves is a basic fire-lighting creation.

Modern matches were made possible by the discovery of phosphorus, a substance which catches fire at a low temperature.

In the nineteenth century, various forms of ‘matches’ were designed using phosphorus. Often, stripes of wood were tipped with white or yellow phosphorus. However white and yellow phosphorus is highly flammable, and dangerous to use.

The first safety matches were made in Sweden in 1844, with the introduction of non-poisonous red phosphorous. Instead of putting all the necessary chemicals for ignition on the match-head, the red phosphorous was painted onto the striking surface of the match box.

Fact File Stone Age people made fire using a simple wooden stick called a fire drill. The drill was turned quickly over a piece of dry wood until it produced enough heat to start the fire.

 

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Fire has been known to man since the earliest times. Archaeologists have found evidence of charcoal and charred remains of bone amongst stones, dating back thousands of years.

It is likely that early man knew how to use fire before he understood how to create. If, for example, lightning struck a tree and set it alight, man would have had the use of the fire and would have been able to keep it going.

Cavemen would have noticed sparks created when they trampled on loose stones. It is unlikely though, that they would have immediately understood that the friction of two stones rubbing together created the sparks. It may have been generations before this idea was put into practice. Almost certainly the first fires that man experienced would have started by accident or as the result of nature, hence the lightning idea.

Fact file Coke is a fuel produced by roasting coal in large ‘coke ovens’ at extremely high temperatures. In these ovens, there is not enough oxygen for the coal to burn; instead, it is roasted which removes gases and leaves the almost pure carbon called coke.

 

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On 25-26th April, 1986 a serious accident occurred at the Chernobyl nuclear power station in the Ukraine. Some technicians in the power station attempted a poorly devised experiment. In doing this they shut down the reactor’s safety system. The reactor continued to be powered, but in a dangerous state. The chain reaction in the core of the reactor led to a massive explosion, and radiation was emitted in huge quantities. Contaminated clouds carried the radiation not just over parts of Russia, but over the rest of the world.

Fact File In the 1970s, organizations such as Friends of the Earth and Greenpeace began to campaign on many environmental issues. These included nuclear weapons, destruction of the rainforests, and dumping of toxic waste.

 

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Nuclear weapons were first used in 1945, at the end of World War II. Two bombs were dropped on the Japanese cities of Hiroshima and Nagasaki by the USA.

Hundreds of thousands of people were killed as a result of these two bombs, leaving a trail of destruction never seen in war before.

This was not only an important turning point in history. Nuclear bombs became a new, deadly threat with huge, a destructive consequences. The nuclear age had begun.

Fact File In 1962 the Cuban crisis erupted when the USA discovered that the USSR was building missile sites on the island of Cuba in the Caribbean. The two superpowers came to the brink of war before the USSR agreed to withdraw the weapons.

 

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Although the time cannot be pinpointed exactly, it is widely believed that gold mining dates back about 5,000 years. The first gold was mined in Egypt, and wall paintings have been found which show gold mining in its various stages of production. Gold was extracted (panned) from river water; this was achieved by sifting out the lighter sands in the water to leave the heavier, gold particles behind. By 3,000 BC gold rings were used as a form of payment. With the exception of coins, gold was used only for decorative purposes.

Around 2,000 BC mine shafts were constructed to obtain gold found in ores deep in the ground; the Greeks and Romans became particularly good at this.

Fact File The gold standard was a monetary system in which the standard unit of currency is a fixed quantity of gold. It was first put into operation in Great Britain in 1821.

 

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The hovercraft was invented in 1955 by the British scientist Christopher Cockerell. He decided to solve a problem that had been baffling scientists for 80 years. In the 1870s, the British engineer John Thornycroft began to design a ship that moved along on a cushion of air to reduce friction between the ship’s hull and the water. He was unable to work out how to contain the cushion of air under the boat, but Cockerell solved this by attaching a rubber skirt to the bottom of the boat. This idea worked perfectly and the hovercraft was born.

Fact File A boat is a pretty large object, yet it floats easily on the surface of water. This is because the fluid actually holds it up. The liquid offsets the force of gravity. If you want to feel this force, just take a blown-up beach ball into water. The water seems to push up the ball.

 

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The first ever powered, sustained and controlled aeroplane flight took place at Kitty Hawk, North Carolina, USA, on December 17, 1903.

Orville Wright and his brother Wilbur both designed and built the plane for this historic flight. Orville piloted the first flight in the aircraft, aptly named the Flyer. He travelled 120 feet through the air in 12 seconds; Wilbur managed 175 feet in 12 seconds straight after this.

They each had one more attempt: Orville flew 200 feet in 15 seconds, before Wilbur recorded the longest flight of the day, travelling 852 feet in 59 seconds.

Fact File Concorde is a supersonic airliner. The sonic ‘boom’ it produces, together with noise and air pollution concerns, has limited the development of such aircraft.

 

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Historical documents and excavations have discovered that stained glass was around as far back as the 12th century. These are true stained glass windows which tell a pictorial story and are considered to be the invention of Western Europe.

Religious writings dating as far back as 240 AD mention the existence of tinted glass in windows of the early Christian basilicas (churches).

Stained glass windows of medieval times were basic in their manufacture. The window opening was filled with thin sheets of marble or wood, with holes pierced through. Tinted glass was placed in the holes; this was known as a mosaic window. Leading was also used to join pieces of glass together to make attractive patterns in the windows.

Fact File Circular turrets on medieval castles had very unusual windows – they were very narrow slits. Because they were built as fortresses the windows were designed to minimize the chance of being hit by arrows.

 

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The first books were made about 4,000 years ago by the Egyptians, who used flattened layers of papyrus (a red-like water plant) to make sheets. The ‘books’ they made were collections of rolled papyrus sheets – very different to a book of today.

In the middle of the fifth century, parchment (sheet skin) replaced papyrus. Parchment sheets were placed on top of one another and bound down one side with leather tongs.

But it was in the in the Middle Ages that books as we know them today evolved. Vellum (calf skin) was made into sheets, and each piece was folded down the middle. Four vellum sheets made eight pages and was considered a section. Unlike parchment, vellum was thick enough to be written on both sides. Finished sections were sewn together down the back fold (the spine) and covered with wooden boards front and back. The boards and spine were then covered with leather; the result was a book similar to that of today.

Fact File  In about AD 500 monks would spend endless hours creating handwritten books decorated (illuminated) with colorful letters and images. The work was slow and painstaking, but worthwhile because it was another way to show dedication to God.

 

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The first paper was made about 2,000 years ago in China, by a man called Ts’ai Lun. He took the stringy inner bark of the Mulberry tree and pounded it in water until it became a mass of flattened threads. He then placed this pulped solution onto a flat tray of fine bamboo strips.

The water was allowed to drain through the bamboo, and the threads in the bamboo were left to dry. The dried result was a flat, fibrous material considered to be the very first paper. As with all new discoveries, improvements are gradually made. One way of achieving this was to brush starch over the paper.

The secret of paper making soon became world-wide knowledge as Chinese traders travelled to Russia and the Middle East. From there, the art of paper making spread to Europe.

A revolutionary invention, paper-making began to be produced in mass quantities. The first continuous paper-making machine was developed in France in 1798 by next century, the Fourdrinier brothers in London developed the idea further.

Fact File The Chinese had another secret, they were the only people who knew how to make silk. European traders would take the long journey to take silk back to Europe.

 

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Clay is believed to have been used to make ceramic objects for at least 15,000 years. Certainly, fragments of clay pots have been found which date back to the Neolithic period, over 10,000 years ago.

As early as 5,000 years ago people learned how to make their clay pots stronger and watertight, using fire. People soon discovered that by burning clay, its properties changed completely.

Thu uses of clay broadened from making small vessels to building materials. Clay-based bricks and tiles were amongst the first composite materials. Egyptian wall paintings of 5,000 years ago show clay workers making such bricks and pots.

The more adept at using clay people became, the more intricate the products they made. Some pottery which dates back thousands of years shows a high artistic quality in their production; examples of this are common from the Far East.

Through the ages, the use of clay in construction increased even more. Still today, ceramics is a huge industry world-wide.

Fact File Ancient brick-makers fired bricks in kilns (special ovens) to produce building materials for structures that were intended to last.

 

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Plastics are made by a chemical process called polymerization. Even without today’s technology and up-to-date knowledge, chemists of the nineteenth century understood the making of plastic. The first plastic, vinyl chloride, was made in 1838. This was closely followed by styrene in 1839, acrylics in 1843 and polyester in 1847. But at the time, no-one realized the potential for their use.

Later that century, chemists decided to find chapter, substitute manufacturing materials. In 1869 John Hyatt discovered Celluloid while trying to find a substitute for ivory. This was a revolutionary material that was tough and malleable; it started a wave of chemists developing new synthetic materials.

However the biggest development of plastics was by Leo Baekeland, who discovered phenolformaldehyde in 1909. He found that this could be moulded into any shape and was cheap to produce. He called the product Bakelite and it was the first synthetic material to be produced in large quantities for mass use.

Fact file Plastic is an ideal material for producing rainwear. It is water-resistant, air-permeable, shrink-resistant and can be easily wiped down.

 

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           Thousands of films have taken inspiration from Shakespeare. Akira Kurosawa, renowned Japanese filmmaker, directed Throne of Blood, which is an adaptation of Macbeth. His Ran, directed in 1985, is inspired by King Lear. My Own Private Idaho, by Gus Van Sant, is influenced by Shakespeare’s Henry IV. Laurence Olivier is probably the most famous filmmaker and actor who have successfully adapted Shakespeare’s play. His Henry V, Hamlet and Richard III are popular films.

           Shakespeare has wielded his influence in India too. Vishal Bharadwaj’s Omkara, Maqbool and Haider have been both popular and critical successes. Jayaraj’s Kannaki, Kaliyattam and Veeram are popular Shakespeare adaptations from Kerala.

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