My Science School

He did indeed. Or more accurately, he pushed a needle behind his eye and with it, indented the sclera. The needle never entered the eye.

By doing so, he stimulated his retina in many spots and noted a "phosphene" or glowing spot that resulted from the pressure. From this he was able to "map" his own retina against where he saw the spots. This map conformed to the map on the back of a rabbit's retina that he made by shining light from a window, through a pinhole, into the rabbit's eye that had an opening cut away from the sclera allowing him to see into the rabbit's eye.

And thus Newton showed how the rays of light enter our eye by an optical system now called the camera design. And how the retina represents the outside world but with inversion (up is down and left is right).

Newton was a dedicated scientist who was willing to accept some pain and personal risk to satisfy his curiosity.

 

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The escalator is a moving staircase that helps people to move between floors at public places like malls, train, stations, airports etc.

The first idea of “revolving stairs” was patented by Nathan Ames in 1859 in USA, but it never saw the light of day. In the 1890s, American engineer Jesse W. Reno installed an “inclined elevator” at Coney Island, an amusement park in New York City. The 7-feet long conveyor belt was inclined at a 25 degree angle. It was the first example of a working escalator. The term ‘escalator’ was coined by Charles Seeberger, an American inventor, from the Latin word scala for steps and the word ‘elevator’, which had already been invented. He joined hands with the pioneering elevator company, Otis, and produced the first commercial wooden escalator which won the first prize at the Paris 1900 Exposition Universelle in France. Soon, escalators were installed in Europe and USA. As the Otis Elevator Company held the trademark rights to the word ‘escalator’ until 1950, other manufacturers called them by different names like Moving Stairs and Motorstair. Today, Otis and Schindler are the largest makers of escalators in the world.

 

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In 1774, the English chemist Joseph Priestley announced that he had discovered ar element within the air. Previously it had been thought that air itself was an element. However, Priestley’s achievement is an example of something that happens quite frequently in science. Although Priestley undoubtedly did discover the presence of oxygen, he was not the first to do so. A Swedish chemist called Carl Scheele had discovered it some months before, and it was not until some months later that a French chemist, Antoine Lavoisier, used Priestley's work to explain what oxygen is and its importance in respiration and combustion. He also gave oxygen its name. The sharing of scientific knowledge moves our understanding of the world forward. No one person can put together all the pieces of the jigsaw puzzle.

Priestley entered the service of the Earl of Shelburne in 1773 and it was while he was in this service that he discovered oxygen. In a classic series of experiments he used his 12inch "burning lens" to heat up mercuric oxide and observed that a most remarkable gas was emitted. In his paper published in the Philosophical Transactions of the Royal Society in 1775 he refers to the gas as follows: "this air is of exalted nature…A candle burned in this air with an amazing strength of flame; and a bit of red hot wood crackled and burned with a prodigious rapidity, exhibiting an appearance something like that of iron glowing with a white heat, and throwing sparks in all directions. But to complete the proof of the superior quality of this air, I introduced a mouse into it; and in a quantity in which, had it been common air, it would have died in about a quarter of an hour; it lived at two different times, a whole hour, and was taken out quite vigorous."

Although oxygen was his most important discovery, Priestley also described the isolation and identification of other gases such as ammonia, sulphur dioxide, nitrous oxide and nitrogen dioxide.

The Leeds Library holds important archival material on Priestley's time there. It was while he was in Leeds that he began his most important scientific researches namely those connected with the nature and properties of gases. A bizarre consequence of this is that Priestley can claim to be the father of the soft drinks industry. He found a technique for dissolving carbon dioxide in water to produce a pleasant "fizzy" taste. Over a hundred years later Mr Bowler of Bath benefited from this when he formed his soft drinks industry.

Priestley should be included in any pantheon of scientists. The bicentenary of his death is an opportune time to reassess his life and work and several events are planned during the year. He possessed enormous scientific skills and originality of thought as well as having the courage to promote unpopular views. He was a man of rare insight and talent.

Sir Edmond Halley’s name is remembered because he was the first person to predict that the comet he saw in 1682 followed a path that would bring it within sight of the Earth again in 1758. Unfortunately, he was no longer alive at that date to see his prediction come true, but his achievement was recognized and his name attached to the comet ever afterwards. In fact, the comet can be seen from Earth every 75-79 years. Its appearance was first recorded by Chinese astronomers in 240BC. The comet, still an unexpected visitor, also appeared in 1066 and was embroidered onto the Bayeux Tapestry, which records the Norman invasion of England.

Edmond (or Edmund) Halley was an English scientist best known for predicting the orbit of the comet that was later named after him. Though he is remembered foremost as an astronomer, he also made significant discoveries in the fields of geophysics, mathematics, meteorology and physics.           

In 1704, Halley was appointed the Savilian professor of geometry at Oxford. Continuing his work in observational astronomy, Halley published "A Synopsis of the Astronomy of Comets" in 1705. In this work, he showed that comet sightings of 1456, 1531, 1607 and 1682 were so similar that they must have been the same comet returning. He predicted that it would return in 1758.

In 1716, Halley devised a method for observing transits of Venus across the disk of the sun in order to determine the distance of Earth from the sun. He also proposed two types of diving bells for exploring underwater. In 1718, by comparing star positions with data recorded by the Greek philosopher Ptolemy, he deduced the motion of stars.

In 1720, Halley succeeded Flamsteed as Astronomer Royal. He continued to make observations, such as timing the transits of the moon across the meridian, which he hoped would eventually be useful in determining longitude at sea.

Halley died Jan. 14, 1742, in Greenwich, England. He did not survive to see the return of what later was named Halley's Comet, on Christmas Day in 1758.

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At one time tens or even hundreds of years might have passed between a scientist’s discovery of a potentially useful fact or method and its use by a wide range of other people. Nowadays, the process is much quicker. This is partly because research is often very expensive and there is pressure to find a commercial use for an invention to help to pay for new research. Modem methods of mass production and global advertising also mean that new products can become popular very quickly.

Hundreds of years ago, news about new products travelled very slowly. Today, advertising is aimed at individual markets and ensures that as many people as possible are aware of what is available.

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Galileo Galilei (1564-1642) was an Italian scientist who worked on many mechanical problems but is perhaps best known for his astronomical observations. These supported the ideas developed by Nicholas Copernicus (1473-1543), a Polish scientist. He claimed that rather than the Sun orbiting the Earth, the Earth orbits the Sun. This idea went against the teachings of the Church, so Copernicus did not tell many people about it. Indeed, when Galileo spoke out in its support, he was put on trial and forced to withdraw his claim. Even today, scientific discoveries are not always popular when they go against long-held beliefs.

Italian astronomer Galileo Galilei provided a number of scientific insights that laid the foundation for future scientists. His investigation of the laws of motion and improvements on the telescope helped further the understanding of the world and universe around him. Both led him to question the current belief of the time — that all things revolved around the Earth.

The Ancient Greek philosopher, Aristotle, taught that heavier objects fall faster than lighter ones, a belief still held in Galileo's lifetime. But Galileo wasn't convinced. Experimenting with balls of different sizes and weights, he rolled them down ramps with various inclinations. His experiments revealed that all of the balls boasted the same acceleration independent of their mass. He also demonstrated that objects thrown in the air travel along a parabola.

At the same time, Galileo worked with pendulums. In his life, accurate timekeeping was virtually nonexistent. Galileo observed, however, that the steady motion of a pendulum could improve this. In 1602, he determined that the time it takes a pendulum to swing back and forth does not depend on the arc of the swing. Near the end of his lifetime, Galileo designed the first pendulum clock.

Galileo is often incorrectly credited with the creation of a telescope. (Hans Lippershey applied for the first patent in 1608, but others may have beaten him to the actual invention.) Instead, he significantly improved upon them. In 1609, he first learned of the existence of the spyglass, which excited him. He began to experiment with telescope-making, going so far as to grind and polish his own lenses. His telescope allowed him to see with a magnification of eight or nine times. In comparison, spyglasses of the day only provided a magnification of three.

It wasn't long before Galileo turned his telescope to the heavens. He was the first to see craters on the moon, he discovered sunspots, and he tracked the phases of Venus. The rings of Saturn puzzled him, appearing as lobes and vanishing when they were edge-on — but he saw them, which was more than can be said of his contemporaries.

The spinning jenny was one of the inventions that revolutionized textile production in the eighteenth century. For thousands of years, spinners were able to produce only one thread at a time, using devices such as spinning wheels. Then in 1764, James Hargreaves, an English weaver, invented a machine that could be operated by one person but spin several threads at the same time.

During the 1700s, a number of inventions set the stage for an industrial revolution in weaving. Among them were the flying shuttle, the spinning jenny, the spinning frame, and the cotton gin. Together, these new tools allowed for the handling of large quantities of harvested cotton.

Credit for the spinning jenny, the hand-powered multiple spinning machine invented in 1764, goes to a British carpenter and weaver named James Hargreaves. His invention was the first machine to improve upon the spinning wheel. At the time, cotton producers had a difficult time meeting the demand for textiles, as each spinner produced only one spool of thread at a time. Hargreaves found a way to ramp up the supply of thread.

The people who took the raw materials (such as wool, flax, and cotton) and turned them into thread were spinners who worked at home with a spinning wheel. From the raw material they created a roving after cleaning and carding it. The roving was put over a spinning wheel to be twisted tighter into thread, which collected on the device's spindle.

The original spinning jenny had eight spindles side by side, making thread from eight rovings’ across from them. All eight were controlled by one wheel and a belt, allowing for much more thread to be created at one time by one person. Later models of the spinning jenny had up to 120 spindles.

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An invention is a new method, material or machine that applies theoretical principles to a practical use. That does not mean that the inventor necessarily understands why his invention works! Inventions may be the result of hard work, or luck, or both. Very often, it is the name of the person who popularized the new idea that we remember, not the person who first thought of it.

An invention is a unique or novel device, method, composition or process. The invention process is a process within an overall engineering and product development process. It may be an improvement upon a machine or product or a new process for creating an object or a result. An invention that achieves a completely unique function or result may be a radical breakthrough. Such works are novel and not obvious to others skilled in the same field. An inventor may be taking a big step toward success or failure.

Some inventions can be patented. A patent legally protects the intellectual property rights of the inventor and legally recognizes that a claimed invention is actually an invention. The rules and requirements for patenting an invention vary by country and the process of obtaining a patent is often expensive.

Another meaning of invention is cultural invention, which is an innovative set of useful social behaviours adopted by people and passed on to others. The Institute for Social Inventions collected many such ideas in magazines and books. Invention is also an important component of artistic and design creativity. Inventions often extend the boundaries of human knowledge, experience or capability.

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In the eighteenth century, wealthy and influential men often interested themselves in more than one branch of learning. The American Benjamin Franklin was a statesman, printer, author and scientist. He left school at twelve, being the fifteenth child of seventeen, but soon made up for his lack of formal education. As well as his political work, he conducted many experiments concerning electricity. In 1752, he flew a kite in a thunder-storm, attaching a metal key to the damp string. An electrical charge ran down the string and Franklin was able to feel it jump to his finger when he approached the key. From this he concluded that lightning was an electrical spark and in 1753 launched his invention of the lightning conductor.

By 1750, in addition to wanting to prove that lightning was electricity, Franklin began to think about protecting people, buildings, and other structures from lightning. This grew into his idea for the lightning rod. Franklin described an iron rod about 8 or 10 feet long that was sharpened to a point at the end. He wrote, "The electrical fire would, I think, be drawn out of a cloud silently, before it could come near enough to strike..." Two years later, Franklin decided to try his own lightning experiment. Surprisingly, he never wrote letters about the legendary kite experiment; someone else wrote the only account 15 years after it took place.

In June of 1752, Franklin was in Philadelphia, waiting for the steeple on top of Christ Church to be completed for his experiment (the steeple would act as the "lightning rod"). He grew impatient, and decided that a kite would be able to get close to the storm clouds just as well. Ben needed to figure out what he would use to attract an electrical charge; he decided on a metal key, and attached it to the kite. Then he tied the kite string to an insulating silk ribbon for the knuckles of his hand. Even though this was a very dangerous experiment, some people believe that Ben wasn't injured because he didn't conduct his test during the worst part of the storm. At the first sign of the key receiving an electrical charge from the air, Franklin knew that lightning was a form of electricity. His 21-year-old son William was the only witness to the event.

Two years before the kite and key experiment, Ben had observed that a sharp iron needle would conduct electricity away from a charged metal sphere. He first theorized that lightning might be preventable by using an elevated iron rod connected to earth to empty static from a cloud. Franklin articulated these thoughts as he pondered the usefulness of a lightning rod.

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Without steam catapults most modern, heavy aircrafts would be unable to take off from their carriers. Today, every aircraft carrier has them.

In operation, the aircraft taxis into position and a wire loop called a hold back is connected between the rear of the aircraft and a strong point on the deck; it has a weak link in its centre.

A towbar near the aircraft’s front wheel is lowered into a shuttle that attaches the aircraft to the catapult with a hook mechanism. It is the only part of the catapult visible on the flight deck.

Two parallel cylinders at least 150ft (45m) long, run under the deck ahead of the aircraft. The cylinders house two pistons which are both fixed to the shuttle. Steam is supplied to the cylinders from the ship’s boilers via an accumulator where pressure is built up. Pressure is varied for launching aircraft of differing weight.

At launch, the aircraft selects full power, but is restrained by the hold back. When the catapult is fired the combined force of the engines and steam pressure break the weak link and the aircraft hurtles forward, reaching about 135 knots (250km/h) 50yds (45m).

At the end of the launch the aircraft flies out of the shuttle. Probes on the front of the pistons ram into a water reservoir, bringing them to rest in a few feet. The shuttle is then res-positioned for the next launch – carriers can launch an aircaft every 2 minutes per catapult. American carriers have up to four catapults, so a plane can be launched every 30 seconds.

The steam catapult was invented by Commander C.C. Mitchell, of Britain's Royal Navy, an in 1949 it was installed for trails in HMS Perseus. Steam catapults were installed on carriers worldwide after the US Navy adopted the equipment in 1954.

 

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               Leonardo de Vinci (1452-1519) was thought until recently to have been the first to design a parachute. But drawings have now been found that were made five years before da Vinci’s sketches, possibly by an engineer in Siena central Italy.

               However, the first man to make and successfully use a parachute was a Frenchman, Andre Garnerin (1770-1825), who stretched cloth across a bamboo framework and parachuted from a balloon over Paris in 1797. It was an uncomfortable descent as the fabric was too thick o spill out any wind, and the parachute came down swinging violently like a pendulum. Garnerin was is a tiny basket, to which he clung tightly until his rough landing on the plain of Monceau. The parachutes of those days were developed from the crude canvas devices used to descend from hot air balloons.

               Modern parachutes are made of pure silk or good-quality nylon in small panels and have a small pilot parachutes which open first and helps to pull out the main parachute.

            The first boat ever to be moved by steam power was designed by a Frenchman Jacques Perier and tested on the Seine in Paris in 1775. But the first really successful steamboat was built by Perier’s fellow countryman, the Marquis Claude de Jouffroyd’Abbans. His craft which was 141 feet long and equipped with straight-paddled side wheels travelled several hundred yards against the current on the Saone at   Lyons on July 25, 1783.

              Among early American pioneers was James Rumsey who in 1786 drove a boat at four miles an hour on the Potomac River, propelled by a jet of water pumped out at the stern. Between 1786 and 1790 John Fitch experimented in the Delaware River at Philadelphia with different methods of propulsion, including paddle wheels a screw propeller and steam-driven oars.

              The first to apply successfully the principle of steam to screw propellers was John Stevens whose boat, equipped with two propellers was John Stevens whose boat, equipped with two propellers, and crossed the Hudson River in 1804. However, his achievements was soon eclipsed by Robert Fulton’s 150-foot long paddle wheeler Clermont which in 1807 covered the 150 miles from New York to Albany in 30 hours at a maximum speed of five miles an hour. With Fulton in command on the Hudson, Stevens looked elsewhere, and in 1808 his new boat, the Phoenix, sailed out of New York harbor to become the first steamboat ever to go to sea.

              Both Stevens and Fulton were following in the steps of the Scottish inventor William Symington who in 1802 constructed a steamboat in Scotland, the Charlotte Dundas, which was used as a tug on the forth and Clyde Canal. The Charlotte Dundas was a paddle-wheel steamer used this method of propulsion.

          The earliest wheels so far discovered were found in graves at Kish and Susa, two ancient Mesopotamian cities. These wheels are believed to date from 3,500 B.C. they were made from three planks, clamped together with copper clasps. This kind of wheel also existed in ancient times in Europe and the Near East. No one is sure where the wheel was invented, but this archaeological evidence suggests it was probably In ancient Mesopotamia

            A wheel with proper spokes was not invented until after 2,000 B.C. there are records of this wheel in northern Mesopotamia, central Turkey, and north-east Persia. By the 15th century B.C., spoked wheels were being used on chariots in Syria, Egypt, and the western Mediterranean.

           The solid wheel was used mostly in farming. Tripartite wheels- wheels with three spokes- were being used in the Bronze age in Denmark, Germany and Northern Italy for carts.

          The invention of the wheel made it possible for people to transport heavy objects much more easily. It also enabled them to travel farther and trade with each other more easily, and so find out about other countries and customs.

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               The first ride able bicycle was made by Kirkpatrick Mac Milan of Dum-friesshire, Scotland, in 1839, although an attempt to construct one had been made by Jean Theson at Fontainebleau, France, in 1645.

               Before this, crude machines had been made, which had no farm o f steering and had to be propelled by publishing the feet against the ground. Machines of this type appear on bas-reliefs in Babylon and Egypt and on frescoes in Pompeii. In England, a stained glass window, dated 1580, in the church of Stoke Poges, Bucking hamshire shows a cherub astride such a machine.

               But all these machines seem to have been four-wheeled. The true bicycle belongs to the 19th Century.

               Macmillan’s bicycle was driven by rods attached from pedals to a sprocket on the rear wheel. The first chain-driven bicycle was produced by Tribout and Meyer in 1869. In this year the first bicycle show-in Paris and the first bicycle road race –from Paris to Rouentook place.

              An Englishman, James Starley, of Coventry in Warwickshire, is known as “the father of the cycle industry”. In 1871 he introduced a bicycle with a large driving wheel and a smaller trailing wheel. This was the “ordinary” bicycle, known to everyone as the penny-farthing. In 1874 a chain-driven bicycle with two wheels of equal diameter was designed by H.J. Lawson. This is known as the safety bicycle and became enormously popular from about 1885 when the Rover safety bicycle was built by John K. Starley, James’s nephew.

             The pneumatic tyre - in other words, a tyre filled with air-was invented in 1888 by John Boyd Dunlop, a veterinary surgeon of Belfast, Northern Ireland. By 1893 the design of the bicycle had been developed into the modern diamond frame with roller-chain drive and pneumatic-tyred wheels.

The first contact lenses were made by A.E. Fick in 1887, but were not successful. During the early part of this century opticians tried to produce extremely thin shell-like lenses to fit closely over the eye. An impression was taken of the eye and a glass shell made which, with a suitable fluid under it, covered most of the eye. After 1938, plastic was used instead of glass, and in about 1950, smaller lenses were introduced which covered only the cornea and floated on a layer of tears. These lenses, only 7 to 11 mm in diameter and 0.1 to 1mm thick can usually be worn all day without being removed.

    Besides being invisible, contact lenses provide a much wider field of vision than spectacles. They are more practical for use in active sports because they are not easily lost or broken, and they can be tinted for use as sunglasses. But contact lenses are not effective in all cases of eye trouble. They are also expensive, and some people find difficulty in learning to wear them.

    As research continues, even smaller and more flexible lenses are being developed.

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