My Science School

Braille, universally accepted system of writing used by and for blind persons and consisting of a code of 63 characters, each made up of one to six raised dots arranged in a six-position matrix or cell. These Braille characters are embossed in lines on paper and read by passing the fingers lightly over the manuscript. Louis Braille, who was blinded at the age of three, invented the system in 1824 while a student at the Institution Nationale des Jeunes Aveugles (National Institute for Blind Children), Paris.

The Frenchman Valentin Hauy was the first person to emboss paper as a means of reading for the blind. His printing of normal letters in relief led others to devise simplified versions; but, with one exception, they are no longer in use. The single exception is Moon type, invented in 1845 by William Moon of Brighton, England, which partly retains the outlines of the Roman letters and is easily learned by those who have become blind in later life. Books in this type are still in limited use by elderly people, particularly in Great Britain.

Writing Braille by hand is accomplished by means of a device called a slate that consists of two metal plates hinged together to permit a sheet of paper to be inserted between them. Some slates have a wooden base or guide board onto which the paper is clamped. The upper of the two metal plates, the guide plate, has cell-sized windows; under each of these, in the lower plate, are six slight pits in the Braille dot pattern. A stylus is used to press the paper against the pits to form the raised dots. A person using Braille writes from right to left; when the sheet is turned over, the dots face upward and are read from left to right.

Braille is also produced by special machines with six keys, one for each dot in the Braille cell. The first Braille writing machine, the Hall Braille writer, was invented in 1892 by Frank H. Hall, superintendent of the Illinois School for the Blind. A modified form of this device is still in use today, as are later, similar devices. One innovation for producing Braille is an electric embossing machine similar to an electric typewriter, and electronic computer processing is now routine.

Credit : Britannica 

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The toy came into the USA in the 1920s from the Philippines where the word 'yo yo' means 'come come'. In the Orient and ancient Greece yo-yos had been popular for centuries.

Duncan was not the inventor of the yo-yo; they have been around for over twenty-five hundred years. In fact, the yo-yo is considered the second oldest toy in history, the oldest being the doll. In ancient Greece, the toy was made of wood, metal and terra cotta. The Greeks decorated the two halves of the yo-yo with pictures of their gods. As a right of passage into adulthood Greek children often gave up their toys and placed them on the family altar to pay homage.

Around 1800, the yo-yo moved into Europe from the Orient. The British called the yo-yo the bandalore, quiz, or the Prince of Wales toy. The French used the name incroyable or l'emigrette. However, it is a Tagalog word, the native language of the Philippines, and means "come back." In the Philippines, the yo-yo was used as a weapon for over 400 hundred years. Their version was large with sharp edges and studs and attached to thick twenty-foot ropes for flinging at enemies or prey.

People in the U.S. started playing with the British bandalore or yo-yo in the 1860s. It was not until the 1920s that Americans first heard the word yo-yo. Pedro Flores, a Philippine immigrant, began manufacturing a toy labeled with that name. Flores became the first person to mass-produce toy yo-yos, at his small toy factory located in California.

Credit : Thought Co.

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A space that contains absolutely nothing! Scientists believe that it is impossible to have a complete vacuum-an empty space with no air or substance whatsoever.

So a vacuum as we know it, is an enclosed space from which as much air and matter as possible has been removed.

A thermos flask has a double wall inside, with a vacuum between the two walls. Hot liquid is kept hot because the heat cannot pass through the vacuum by convection or conduction.

First, forget the vacuum cleaner as an analogy to the vacuum of space, Jackie Faherty, a senior scientist in the Department of Astrophysics at the American Museum of Natural History in New York City, told Live Science. The household cleaning machine effectively fills itself with dirt and dust sucked out of your carpet. (That is, the vacuum cleaner uses differential pressure to create suction. Suction cleaner might be a better name than vacuum cleaner). But the vacuum of space is the opposite. By definition, a vacuum is devoid of matter. Space is almost an absolute vacuum, not because of suction but because it's nearly empty. 

That emptiness results in an extremely low pressure. And while it's impossible to emulate the emptiness of space on Earth, scientists can create extremely low pressure environments called partial vacuums.

Even with the vacuum cleaner analogy out, "understanding the concept of the vacuum is almost foreign because it's so contradictory to how we exist, Faherty said. Our experience as humans is completely confined to a very dense, crowded and dynamic fraction of the universe. So, it can be hard for us to really understand nothingness or emptiness, she said. But in reality, what's normal for us on Earth, is actually rare in the context of the universe, the vast majority of which is nearly empty.  

Credit : Live Science 

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The Penny Black was first used in England in May 1840. Six million were printed in unperforated sheets of 240. Post Office staff had to cut the stamps into strips. It cost one penny to deliver a letter, whatever the distance.

At the time, rumours circulated that the stamp was one of the first Penny Blacks ever printed.

It took three years of research to prove that was true and get official authentication from The Royal Philatelic Society, London, and the British Philatelic Association.

That certification has raised its value significantly and a recent stamp sale has stoked Mr Holyoake's hopes that The Wallace Document would fetch a record-breaking price.

Earlier this year, Sotheby's auctioned a British Guiana One-Cent Magenta for $US8.3 million ($11 million) and Mr Holyoake believes his stamp is worth even more.

Credit : ABC News

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In 1938 he invented the ballpoint pen. He was a hungarian journalist and realised that the quick-drying ink he had seen used by the printing trade could be adapted for use in a pen.

A lot of improvements were made to pens in general over the years, leading to a battle over the rights to Biro's invention. The newly-formed Eterpen Company in Argentina commercialized the Biro pen after the Biro brothers received their patents there. The press hailed the success of their writing tool because it could write for a year without refilling.

Then, in May 1945, Eversharp Company teamed up with Eberhard-Faber to acquire exclusive rights to Biro Pens of Argentina. The pen was rebranded as the “Eversharp CA,” which stood for “capillary action.” It was released to the press months in advance of public sales.

Less than a month after Eversharp/Eberhard closed the deal with Eterpen, a Chicago businessman, Milton Reynolds, visited Buenos Aires in June 1945. He noticed the Biro pen while he was in a store and recognized the pen’s sales potential. He bought a few as samples and returned to America to launch the Reynolds International Pen Company, ignoring Eversharp’s patent rights.

Reynolds copied the Biro pen within four months and began to sell his product by the end of October 1945. He called it "Reynolds Rocket" and made it available at Gimbel’s department store in New York City. Reynolds’ imitation beat Eversharp to market and it was immediately successful. Priced at $12.50 each, $100,000 worth of pens sold their first day on the market.

Britain was not far behind. The Miles-Martin Pen Company sold the first ballpoint pens to the public there at Christmas 1945. 

By 1957, Parker had introduced the tungsten carbide textured ball bearing in their ballpoint pens. Eversharp was in deep financial trouble and tried to switch back to selling fountain pens. The company sold its pen division to Parker Pens and Eversharp finally liquidated its assets in the 1960s.

Credit : Thought Co.

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This phrase means totally dead - extinct! The dodo was discovered in Mauritius in 1507 and was extinct by 1681. This big bird with short wings could not fly to escape its enemies.

The phrase is mostly used in casual communication or as a slang. It originates from the fact that the dodo bird is no longer in existence. The dodo was a bird that lived the island of Mauritius. It was somewhat like a turkey and couldn’t fly and was hunted to extinction.

There are jokes made about the extinction of this species of bird due to their lack of intelligence. One of the most prominent ones was in the movie ‘Ice Age’ which showed Dodo birds were collecting food for the doomsday and all ended up dying to protect a few watermelons.

Credit : The Idioms 

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The okapi is a shy animal related to the giraffe. It lives in the dense rainforests of central Africa and eats a diet of leaves and shoots. It was completely unknown until 1900.

The okapi's home is in the tropical rainforest in the northeast region of the Democratic Republic of the Congo (formerly Zaire), in Central Africa. Why does the okapi have zebra-like stripes? These markings, which seem very bold to us, offer great camouflage when an okapi stands in the partial sunlight that filters through its dense rainforest habitat. The stripes may also help a young okapi follow its mother through the dark forest, and they may help adults find each other, too. The okapi’s dark purplish or reddish brown fur is dense and feels like velvet. It’s also oily, so water slides right off, keeping the okapi dry on rainy days. Only male okapi have horns, which are covered by skin, short, and slant backward so they won’t get tangled in forest branches. 

If okapis are related to giraffes, why aren’t they as tall as giraffes? In a rainforest, there are trees with branches hanging down, as well as roots and tree trunks to dodge. Okapis need to have shorter legs and necks to help them swerve around these obstacles. Being really tall is not a good idea in a forest!

Okapis often travel up to 0.5 miles (0.8 kilometers) a day in search of food, usually along trails worn down by generations of okapis. They are generally solitary, unless an adult female has a calf with her. Adult males have home ranges that cover more area, and they can travel up to 2.5 miles (4 kilometers) a day. The males try to keep other males out of their territories but allow females to travel through in search of food.

Both male and female okapis are most active during the afternoon through the evening. They are important forest browsers, eating 40 to 65 pounds (18 to 29 kilograms) of leaves, twigs, and fruits each day and leaving a “pruning line” in the foliage. Okapis use their prehensile tongue to get food by pulling leaves from trees and into their mouth. The tongue is also an important grooming tool, helping to keep the velvety soft, short coat in tip-top shape. Okapis have also been seen eating clay and burnt charcoal, probably for minerals. And just like giraffes, sheep, and goats, okapis are ruminants.

Credit : San Diego Zoo 

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Archimedes was a great mathematician and scientist born in 287 BC. He is mostly remembered for discovering a fact that become known as 'Archimedes' Principle'. All bodies weighed when immersed in fluid, show a loss of weight equal to the fluid they displace.

Archimedes made this startling discovery while he was in his bath. He was so excited that he rushed out in the street naked shouting "Eureka!" This is Greek for "I have found it!"

According to Boundless, the Archimedes principle states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid that is displaced by that object. 

If a glass is filled to the top with water and then ice cubes are added to it, what happens? Just like the water spilled over the edge when Archimedes entered his bathtub, the water in the glass will spill over when ice cubes are added to it. If the water that spilled out were weighed (weight is a downward force), it would equal the upward (buoyant) force on the object. From the buoyant force, the volume or average density of the object can be determined. 

Archimedes was able to determine that the crown was not pure gold due to the volume of the displaced water, because even though the weight of the crown was identical to the weight of the gold that the king gave the crown maker, the volume was different due the various densities of the metals.

Credit : Live Science 

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Food in tin cans was first produced in Britain in 1812 by Donkin and Hall of London. They canned beef, mutton, vegetable stew, soups and carrots. These goods were very useful to the explorers of the day.

In the late 1800s, William Charles Ball and his brothers got into the food preservation jar business and began buying up smaller companies. They quickly became leaders in the industry.

Alexander Kerr invented the easy-to-fill wide-mouth canning jar in 1903 (an innovation that the Ball brothers quickly duplicated). Later, in 1915, Kerr developed the idea of a metal lid with a permanently attached gasket that a man named Julius Landsberger had invented. Kerr came up with a metal disk with a similar gasket, held in place by a threaded metal ring. The modern 2-piece canning lid was born.

Canning technology continues to develop. Brands such as Quattro Stagioni use single piece canning lids that work similarly to the older 2-piece canning lid design.

Credit : The Spruce Eats

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A legendary city of gold supposed to exist in South America. A Spaniard thought he glimpsed a vast city roofed with gold, and since the 16th century many explorers have gone in search of 'the golden'!

When Spanish explorers reached South America in the early 16th century, they heard stories about a tribe of natives high in the Andes mountains in what is now Colombia. When a new chieftain rose to power, his rule began with a ceremony at Lake Guatavita. Accounts of the ceremony vary, but they consistently say the new ruler was covered with gold dust, and that gold and precious jewels were thrown into the lake to appease a god that lived underwater.

The Spaniards started calling this golden chief El Dorado, "the gilded one." The ceremony of the gilded man supposedly ended in the late 15th century when El Dorado and his subjects were conquered by another tribe. But the Spaniards and other Europeans had found so much gold among the natives along the continent's northern coast that they believed there had to be a place of great wealth somewhere in the interior. The Spaniards didn't find El Dorado, but they did find Lake Guatavita and tried to drain it in 1545. They lowered its level enough to find hundreds of pieces of gold along the lake's edge. But the presumed fabulous treasure in the deeper water was beyond their reach.

Credit : National Geographic 

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One day in 1947, a Bedouin boy was looking for a lost goat along the cliffs by the Dead Sea. He threw a stone into the mouth of some caves and heard the sound of breaking pottery.

Once inside he discovered several clay jars containing decayed parchment scrolls, on which were written Bible stories over 2,000 years old. These and many other manuscripts found in caves nearby, became known as the Dead Sea Scrolls one of the most important discoveries of all time!

The manuscripts fall into three major categories: biblical, apocryphal, and sectarian. The biblical manuscripts comprise some two hundred copies of books of the Hebrew Bible, representing the earliest evidence for the biblical text in the world. Among the apocryphal manuscripts (works that were not included in the Jewish biblical canon) are works that had previously been known only in translation, or that had not been known at all. The sectarian manuscripts reflect a wide variety of literary genres: biblical commentary, religious-legal writings, liturgical texts, and apocalyptic compositions. Most scholars believe that the scrolls formed the library of the sect that lived at Qumran. However it appears that the members of this sect wrote only part of the scrolls themselves, the remainder having been composed or copied elsewhere.

The discovery of the Dead Sea Scrolls represents a turning point in the study of the history of the Jewish people in ancient times, for never before has a literary treasure of such magnitude come to light. Thanks to these remarkable finds, our knowledge of Jewish society in the Land of Israel during the Hellenistic and Roman periods as well as the origins of rabbinical Judaism and early Christianity has been greatly enriched.

The first seven Dead Sea Scrolls were discovered by chance in 1947 by Bedouin, in a cave near Khirbet Qumran on the northwest shore of the Dead Sea. Three of the scrolls were immediately purchased by archaeologist E. L. Sukenik on behalf of the Hebrew University; the others were bought by the Metropolitan of the Syrian Orthodox Church in East Jerusalem, Mar Athanasius Samuel. In 1948 Samuel smuggled the four scrolls in his possession to the United States; it was only in 1954 that Sukenik’s son, Yigael Yadin, also an archaeologist, was able to bring them back to this country.

Over the next few years, from 1949 to 1956, additional fragments of some 950 different scrolls were discovered, both by Bedouins and by a joint archaeological expedition of the École Biblique et Archéologique Française and the Rockefeller Museum, under the direction of Professor Father Roland de Vaux. Since then, no further scrolls have come to light, though excavations have been carried out from time to time at the site and nearby.

Credit : The Israel Museum 

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The highest mountain in the world above sea level is Mount Everest in the Himalayas. It is 8,849m (29,030ft) high, although the depth of ice on the peak changes this a little.

It was first climbed in 1953 by Sir Edmund Hillary and the Sherpa, Tensing Norgay. They planted the flags of Britain, Nepal, India and the U.N. on the top.

Among the eleven chosen climbers, Edmund Hillary was selected as a climber from New Zealand and Tenzing Norgay, though born a Sherpa, was recruited from his home in India. Also along for the trip was a filmmaker (Tom Stobart, 1914–1980) to document their progress and a writer (James Morris, later Jan Morris) for The Times, both were there in the hopes of documenting a successful climb to the summit; the 1953 film "The Conquest of Everest," resulted from that. Very importantly, a physiologist rounded out the team.

After months of planning and organizing, the expedition began to climb. On their way up, the team established nine camps, some of which are still used by climbers today.

Out of all the climbers on the expedition, only four would get a chance to make an attempt to reach the summit. Hunt, the team leader, selected two teams of climbers. The first team consisted of Tom Bourdillon and Charles Evans and the second team consisted of Edmund Hillary and Tenzing Norgay.

The first team left on May 26, 1953 to reach the summit of Mt. Everest. Although the two men made it up to about 300 feet shy of the summit, the highest any human had yet reached, they were forced to turn back after bad weather set in as well as a fall and problems with their oxygen tanks.

Credit : Thought Co.

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He was the leader of the Carthaginian army who invaded Italy in 218 BC. He took an army of 40,000 men and 37 elephants over the Pyrenees and the Alps from Spain to Italy. Hannibal floated his elephants across rivers on huge rafts - but he never conquered Rome!

Such an achievement required careful planning and strategizing, but with little physical evidence of the journey available today and few recorded details of the crossing, uncertainty remains about how it was accomplished.

However, in "Secrets of the Dead: Hannibal in the Alps," a new documentary airing on PBS tonight (April 10), a team of experts takes a fresh look at Hannibal’s incredible trip across treacherous mountain terrain. Together, they re-create his long-lost route and reveal the latest discoveries about his historic accomplishment — and depict the famous elephants that played a critical part in his victory against the Romans.

In 218 B.C., when the crossing took place, the powerful nations of Carthage and Rome were at each other's throats. To defeat the Romans, Hannibal did the unthinkable — he led an army through a mountain region spanning about 80,000 square miles (over 207,000 square kilometers) — and descended on Rome from the north, where the nation least expected an attack.

For the documentary, the production team assembled archaeologists, paleontologists, animal trainers and mountaineers, re-creating Hannibal's route on foot and testing evidence and methods along the way, the filmmakers said in a statement.

Credit : Live Science 

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