My Science School

Did you know spiderwebs were used as bandages to treat injuries in ancient times? Spiderwebs are made of spider silk. They were believed to have antiseptic and anti-fungal properties. They helped prevent infection and were said to promote clotting of blood. Now research in spider silk is going on all over the world to explore its relevance to areas of medicine and industry.

If you are in midst of a forest, and get cut by a machete and there’s profuse bleeding, what do you do? You find a cobweb. Funny as it may sound, putting a bunch of cobweb on your wound will make the blood coagulate much faster. Thanks to those thousands of strands of nanowires which act as nucleation lines.

Besides that, since the cobwebs are proteins basically, they are good places for fungi and bacteria to grow. So, the spider knows that and has evolved to keep these bacterial and fungi growths away from its web. Cobwebs are in fact antiseptic and antifungal too. As long as the web is clean, it will not cause any kind of infection if you put it on an open wound.

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A chameleon is a very unique lizard that inhabits warm locations such as rainforests and deserts. They are known for their colour-changing abilities, long tongues, and unusual eye movements. The word chameleon comes from the Latin word chamaeleon, derived from Greek words chamai and leon, meaning ground and lion respectively. So, chameleon means lion on the ground. It is thought that the name refers to the ornate mane-shaped crests around the heads of some species.

The longest chameleon in the world is Parson’s chameleon (Calumma parsonii), which may grow up to 69.5 cm (about 27 inches) long. On the other hand, the world’s shortest chameleon, the male nano-chameleon (Brookesia nana), can be as small as 21.6 mm (about 0.9 inch) long. Most chameleons, however, are 17–25 cm (7–10 inches) long. The body is laterally compressed, the tail is sometimes curled, and the bulged eyes move independently of one another. Also, some chameleons possess helmet-shaped heads.

The chameleon’s specialized vision and a specialized tongue-projection system permit the capture of insects and even birds from a distance. The chameleon’s eyes are very good at detecting and regulating light. The lens of a chameleon’s eye is capable of focusing extremely rapidly, and it can enlarge visual images much like a telephoto lens. Although many other lizards also use the tongue to capture prey, most can expel it only a short distance. 

Credit : Britannica

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Flamingos are wading birds that are easily recognised by their long, stilt-like legs, and striking pink feathers. The bright pink colour comes from beta carotene, a red-orange pigment that's found in the algae and the shrimp that flamingos eat in their wetland environment. This flame-like appearance also gave them their name. In Portuguese and Spanish flamengo means flame-coloured. The genus name Phoenicopterus comes from the Greek word phoinikopteros, which means, "blood red-feathered".

To feed, flamingos tramp the shallows, head down and bill underwater, stirring up organic matter with their webbed feet. They eat various types of food, including diatoms, algae, blue-green algae, and invertebrates such as minute mollusks and crustaceans. While the head swings from side to side, food is strained from the muddy water with small comblike structures inside the bill. The bird’s pink colour comes from its food, which contains carotenoid pigments. The diet of flamingos kept in zoos is sometimes supplemented with food colouring to keep their plumage from fading.

Flamingos constitute the family Phoenicopteridae, which is the only family in the order Phoenicopteriformes. They are sometimes classified in the order Ciconiiformes (herons and storks) but also show similarities to anseriforms (ducks and geese), charadriiforms (shorebirds), and pelecaniforms (pelicans and cormorants).

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Cobra is a species of highly venomous snakes, which expand the neck ribs to form a hood. These snakes are prevalent in India. It is believed that the Portuguese colonists in India gave the snakes their name. Cobra de capello is Portuguese for serpent of the hood or hooded serpent. Its genus name Naja has Indian origins, and may have derived from the Sanskrit word for snake Naga.

The world’s largest venomous snake is the king cobra, or hamadryad (Ophiophagus hannah). Found predominantly in forests from India through Southeast Asia to the Philippines and Indonesia, it preys chiefly on other snakes. Maximum confirmed length is 5.6 metres (18 feet), but most do not exceed 3.6 metres (12 feet). King cobras guard a nest of 20 to 40 eggs, which are laid in a mound of leaves gathered by the female. The guarding parent will strike if a predator or a person approaches too closely. Not all cobras are egg layers.

The Indian cobra (or Indian spectacled cobra, Naja naja) was formerly considered a single species with much the same distribution as the king cobra. Recently, however, biologists have discovered that nearly a dozen species exist in Asia, some being venom spitters and others not. They vary both in size (most ranging between 1.25 and 1.75 metres) and in the toxicity of their venom. Spitters propel venom through the fangs by muscular contraction of the venom ducts and by forcing air out of the single lung.

Credit : Britannica

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Cormorants are large water birds that live in coastal areas or near lakes and rivers, and are usually black, brown, or greyish. Cormorant comes from two Latin words: corvus meaning crow and marinus meaning marine. So, cormorant is another way of saying sea-crow. It may have had its origin in Cornish mythology. In the Comish tale of Jack the Giant Killer, Cormoran is a sea giant. Though cormorants have little in common with crows except for their black plumage, the birds were erroneously thought to be related to ravens till the 16th Century.

Cormorants inhabit seacoasts, lakes, and some rivers. The nest may be made of seaweed and guano on a cliff or of sticks in a bush or tree. The two to four chalky eggs, pale blue when fresh, hatch in three to five weeks, and the young mature in the third year.

Cormorants have a long hook-tipped bill, patches of bare skin on the face, and a small gular sac (throat pouch). The largest and most widespread species is the common, or great, cormorant, Phalacrocorax carbo; white-cheeked, and up to 100 cm (40 inches) long, it breeds from eastern Canada to Iceland, across Eurasia to Australia and New Zealand, and in parts of Africa. It and the slightly smaller Japanese cormorant, P. capillatus, are the species trained for fishing. The most important guano producers are the Peruvian cormorant, or guanay, P. bougainvillii, and the Cape cormorant, P. capensis, of coastal southern Africa.

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Hippopotamuses are large, round, water-loving animals that are native to Africa. Greek writer Herodotus is credited with naming this unusual creature. In Greek, the word hippo means horse and potamos means river. But hippos are not related to horses, they are in fact related to pigs, whales, and dolphins!

Hippo is often attributed to terms related to horse. For instance, hippodrome is a stadium for racing horses (and not hippos). Seahorses belong to a genus called hippocampus

(Hippocampus is Greek for seamonster, and it originally referred to a mythological creature that resembled a horse with wings).

Do you know why our brain area hippocampus is called so? Because the part resembles a seahorse.

Hippos live in sub-Saharan Africa. They live in areas with abundant water, as they spend most of their time submerged to keep their skin cool and moist. Considered amphibious animals, hippos spend up to 16 hours per day in the water, according to National Geographic.

Hippos are social beasts, hanging out in groups called schools, bloats, pods or sieges. Schools of hippos usually consist of 10 to 30 members, including both females and males, although some groups have as many as 200 individuals. No matter the size, the school is usually led by a dominant male.

According to the International Union for Conservation of Nature (IUCN), the common hippo isn't endangered, but it is vulnerable to extinction. The IUCN estimates that between 125,000 and 148,000 hippos remain in the wild. Poaching and habitat loss reduced the hippo's global numbers during the late 1990s and early 2000s, but the population has since plateaued thanks to stricter law enforcement, according to the IUCN.

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Rhinoceros is a giant horn-bearing herbivore that's among the largest living land mammals. It derives its names from its most pronounced feature: the horn. The term stems from the Latin word rhinoceros and Greek word rhinokeros, both of which take root in rhinos, which means nose, and keras, meaning horn. (Keras is also the origin of keratin, the protein that is the main substance of hair, nails, horns, and feathers).

Rhinoceroses are characterized by the possession of one or two horns on the upper surface of the snout; these horns are not true horns but are composed of keratin, a fibrous protein found in hair. Modern rhinoceroses are large animals, ranging from 2.5 metres (8 feet) long and 1.5 metres (5 feet) high at the shoulder in the Sumatran rhinoceros to about 4 metres (13 feet) long and nearly 2 metres (7 feet) high in the white rhinoceros. Adults of larger species weigh 3–5 tons. Rhinoceroses are noted for their thick skin, which forms platelike folds, especially at the shoulders and thighs. All rhinos are gray or brown in colour, including the white rhinoceros, which tends to be paler than the others. Aside from the Sumatran rhinoceros, they are nearly or completely hairless, except for the tail tip and ear fringes, but some fossil species were covered with dense fur. The feet of the modern species have three short toes, tipped with broad, blunt nails.

In rhinoceroses, females do not conceive until about six years of age; gestation is long (16 months in most species), and they give birth to only one calf at a time. The period of birth between calves can range from 2 to 4.5 years. Thus, the loss of a number of breeding-age females to poachers can greatly slow the recovery of rhinoceros populations.

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Orangutans are great apes native to the rainforests of Indonesia and Malaysia. The name orangutan is derived from two Malay words - orang, meaning person and hutan meaning forest. So orangutan means person of the forest. Humans and orangutans share approximately 97% of the DNA and 28 physical traits. Orangutans laugh, recognise faces, 'talk about the past learn from each other, and pass on the knowledge to the next generation. Hence, it is only fitting that we call the animal the 'person of the forest.

Orangutans are not as powerfully built as the gorilla but are larger than the chimpanzee. The adult male is typically twice the size of the female and may attain a height of 1.3 metres (4.3 feet) and a weight of 130 kg (285 pounds) in the wild; females weigh 37 kg (82 pounds) or less. Older males develop wide cheek pads, a unique feature among primates. The typically dark tan or brownish skin is covered with relatively coarse and usually sparse red hair. Adult males and some older adult females may have partially or entirely bare backs, but the hair on a male can be so long as to look like a cape when he moves his arms.

Orangutans are predominantly ripe-fruit eaters, although they consume more than 400 different types of food, including invertebrates and, on rare and opportunistic occasions, meat. Almost every night orangutans construct a sleeping platform in the trees by bending and breaking branches, leaves, and twigs. Unlike the African apes, orangutans frequently use vegetation to protect themselves from the rain.

Credit : Britannica

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Lemurs are 100 or so species of primates in Madagascar. The name lemur derives from the Latin word lemures, which some dictionaries translate as ghosts. In Ancient Rome, lemures were believed to be a kind of eerie-looking malignant dead that wandered the earth at night, causing hurt and injury to the living. It is believed that the name got attached to the primates because of their reflective eyes and their silent nocturnal wanderings.

A number of lemurs are rare or endangered. Several either were not discovered until the late 20th century or were rediscovered after having been thought extinct. Remains exist of species larger than any of today’s lemurs. Some of these may have survived until only 500 years ago. They were probably exterminated by overhunting or habitat modification by the Malagasy people, who arrived on the island less than 2,000 years ago.

Lemurs are less intelligent than monkeys. Their sense of smell is more acute but their vision less so. Although some species are at times active during the day, their eyes seem to be adapted for nocturnal life, trading acuity for increased sensitivity in low light conditions. All lemurs are characterized by a reflective layer (tapetum) behind the retina in the eye, but no fovea or macula lutea; a hairless, moist tip to the muzzle; a noninvasive (epitheliochorial) placenta; comblike forward-directed lower front teeth (with the exception of the aye-aye); and a claw (“toilet claw”) on the second toe of the foot.

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The oldest surviving pencil is a German carpenter's wood-cased pencil dating from the 17th century and now in the Faber-Castell Castle in Stein, Germany.

“This wood encased graphite pencil from the 17th century was found in the 1960s during restoration work on the beams of a house in Langenburg (Swabia). This pre-industrial pencil, made of lime wood with the methods usual at the time, was very probably used by carpenters in their work. It has been in the Faber-Castell Collection since 1994.”

The pencil is held in the Kunozan Toshogu Museum in Shizuoka Prefecture. Electron microscope analysis reveals the graphite is from 16th century Mexico.

This pencil has just stub of graphite at the tip and an advanced feature – a cap! Found in Masamune’s mausoleum at Zuihoden, it isn’t clear to me if the pencil was reburied.

To summarize, Ieyasu’s pencil is older than the Langenburg pencil, and the Masamune pencil is probably (though not definitively) older than the Langenburg pencil. The better known “oldest known pencil” has company.

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Located on the western bank of the Nile, the ancient city of Shedet was the centre of worship for the Egyptian god Sobek, the crocodile god. Dubbed "Crocodilopolis" by the Greeks, inhabitants worshipped a manifestation of Sobek through a sacred crocodile kept at the city, named 'Petsuchos' meaning "son of Sobek". The crocodile was adorned with gold and jewels, and kept in a temple pond with special priests to serve his food! After the residing Petsuchos died, the body would be mummified and given a special burial and then replaced with another crocodile. The city is now known as Medinet el Fayum (City of Faiyum).

Sobek could protect the justified dead in the netherworld, restoring their sight and reviving their senses. Because of his ferocity, he was considered to be the patron of the army.

Worship of Sobek extended to Thebes and Kom Ombo where there was a dual temple dedicated to Sobek and Horus. The left (northern) side was dedicated to Horus the elder (as opposed to Horus son of Isis) while the right side (southern) was dedicated to Sobek. Each temple has its own entrance, chapels and its own dedicated priests. The temple was constructed during the Ptolemaic period, but there is evidence of an older structure at that location which may date from the New Kingdom.

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DISEASE

Wherever people have lived together in large numbers, diseases have spread. As ships travelled around the world, diseases like bubonic plague, flu, and cholera spread from country to country. In the past, treatment was often ineffective as people did not understand the true causes of these diseases. We now know that they are caused by microscopic bacteria and viruses.

BUBONIC PLAGUE

In the 1340s, bubonic plague killed around half the population of Europe, and millions more in Asia and Africa. People believed that they could catch the plague by breathing bad air. The true cause was bacteria, passed on by flea bites.

CHOLERA

These bones in the Paris catacombs are from victims of cholera, a disease that originated in India and was brought to Europe by merchant ships in 1829. It is caused by drinking water polluted with sewage, which carries the cholera bacteria. Victims die a painful death, after hours of vomiting and diarrhoea.

FLU PANDEMIC

A widespread outbreak of disease is called a pandemic. The worst case in history took place in 1918-20, when a deadly strain of flu spread around the globe, killing 50-100 million people. Face masks were widely worn, for it was correctly understood that flu is spread by coughs and sneezes.

SMALLPOX

Smallpox was a disease that could scar, blind, and even kill its victims. Like flu or the common cold, it was caused by a virus, a minute agent that can only grow or reproduce inside the cells of living things. Smallpox is one disease that has been wiped out by modern medicine.

HYGIENE

Until the 1860s, people did not understand the importance of hygiene in preventing infections. Surgeons did not even wash their hands before operating. In 1865, an English surgeon called Joseph Lister began to clean the wounds of his patients with carbolic acid. This killed the bacteria that infected the wounds.

SANITATION

The 19th century saw several cholera pandemics in Europe. These were eventually ended by building proper sewers, which stopped bacteria polluting drinking water. The last European pandemic took place in Russia in 1923. Cholera is still a problem in Asia and Africa, with an outbreak in Yemen in 2016.

BACTERIA

Bacteria are microscopic single-celled organisms that infect wounds and cause diseases. In 1928, Scottish scientist Alexander Fleming discovered that a mould growing in his laboratory killed harmful bacteria. He used this discovery to create a new type of anti-bacterial medicine, called an antibiotic.

VACCINATION

A vaccine is a weak form of a disease that helps the body fights a more serious disease. English doctor Edward Jenner realized that people who caught cowpox (a mild form of smallpox), did not get the deadlier disease. In 1796, he injected eight-year old James Phipps with pus from a cowpox blister. When he later tried to infect the boy with smallpox, James did not catch the disease and the first vaccine had been created.

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MONEY

Before money existed, people traded by bartering, or swapping, different goods. The problem with bartering was that each trader had to want what the other trader was selling. Money was invented as a medium of exchange – something with a recognized value that could be used to buy other goods. Money is usually made of rare materials, such as precious metals or colourful feathers. The first written records of money date back to Mesopotamia (now in southern Iraq) where weighed silver was used about 4,500 years ago.

EGYPTI?? HOARD

In Ancient Egypt, payments were made with various metals and their value was based on weight not shape. This resulted in a wide array of bars, rings, and pieces of gold, silver, and copper.

BURMESE WEIGHTS

During the 18th century, silver weights called “flower silvers” were used as money in Burma (now Myanmar). Liquid silver was poured into a mould, and a floral pattern added.

TRADER’S MANUAL

Coins were regularly shipped overseas in the 16th century. To identify the different coins and their value, Dutch merchants used handbooks detailing foreign currency.

FEATHER MONEY

The Pacific Islanders of Santa Cruz used long coils made of feathers to buy canoes. The brightest and boldest feathers had the highest value.

CHINESE COINS

In 500 BCE, bronze coins in China were made to resemble tools or the cowrie shells of an earlier currency. The shapes were so awkward they were replaced by circular coins with square holes.

BANK NOTE

Paper money has its origins in 10th-century China. Handwritten receipts provided by merchants gained such importance that the government started printing paper receipts for specific sums.

WAMPUM

Native Americans created belts, known as wampum, from white and purple clam shells. These belts represented money and were used to seal deals.

STONE MONEY

Heavy currency was used by the islanders of Yap in the Pacific Ocean. The huge stone discs they used to pay for items were often too weighty to lift, some measuring 4 m (13 ft) across.

CHEQUE

An alternative to cash is a cheque - a form that details how much money should be transferred from one bank account to another. In medieval times, the Knights Templar issued cheques to pilgrims so they could travel across Europe without carrying money.

CREDIT CARDS

First used in 1920s America to buy petrol, many people now rely on plastic credit cards. Issued by banks and businesses, cards are a convenient alternative to cash.

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REVOLUTIONS

A revolution is a sweeping social change that takes place in a short period of time. This is often violent, as unpopular governments are overthrown, either by mass uprisings or small groups of organized revolutionaries. The aim of revolutionaries is to create a better society – to make people more equal, or more free. Yet it is often easier to destroy a bad government than it is to create a better one.

AMERICAN REVOLUTION

Between 1775-81, Britain’s 13 colonies in North America fought a war of independence, in which they successfully threw off the rule of King George III. In their 1776 Declaration of Independence, the American leaders declared that “all men are created equal” with the right to “life, liberty, and the pursuit of happiness”.

FRENCH REVOLUTION

In 1789, rioting against the government of King Louis XVI spread across France. Using the slogan of “liberty, equality, fraternity”, revolutionaries overthrew the king. In 1793, the French leaders launched a reign of terror, during which they executed all opponents, including the king, by guillotine.

RUSSIAN REVOLUTION

The Bolshevik Party, led by Vladimir Lenin, seized power in Russia in October 1917 and founded the first communist state. The communists set about creating a new kind of society, a “workers’ state” based on common ownership of industry and land.

CULTURAL REVOLUTION

In 1949, communists, led by Mao Zedong, took power in China. In 1966, Mao, who feared that China was sliding away from communist principles, launched a “cultural revolution” to root out old ways of thinking. Opponents and intellectuals were persecuted, and the country came close to chaos.

CUBAN REVOLUTION

In 1956-59, Cuban rebels, led by Fidel Castro and Che Guevara (left), overthrew the corrupt government of the dictator, Fulgencio Batista. Although Castro went on to rule as another dictator, he improved conditions for the Cuban poor, and provided them with greater access to hospitals and schools.

VELVET REVOLUTION

Mass protests in November 1989, and a general strike in Czechoslovakia, proved enough to bring down the unpopular communist government. The lack of violence led to this being called the “velvet”, or soft, revolution. Here marchers carry the flag of the new Czech Republic (Czechia).

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INDUSTRIAL REVOLUTION

From the late 18th century, the invention of machines that could do things faster than ever before brought dramatic changes in the way people lived and worked. Known as the Industrial Revolution, these changes took root in Britain and quickly spread to Europe and the USA. It began in the textile industry, with new machines powered first by water and later by steam. This led to a huge demand for coal, to fuel the engines, and iron, to make the machines. New towns sprang up as farm labourers moved from the countryside to work in the factories.

FACTORIES

Huge buildings, called factories, were constructed to house the new machines, row upon row. Machines, such as these looms for weaving cotton into cloth, were powered by a steam engine and the noise they made would have been deafening.

FACTORY WEAR

Factory owners preferred to hire women and children to men, because they were cheaper and easier to discipline. Women in the factories wore heavy, durable clothes, which were products themselves of the Industrial Revolution’s textile boom.

RAILWAYS

In 1804, British inventor Richard Trevithick built the first steam-powered locomotive. Early locomotives carried coal from mines. From 1825, passenger trains were built, and armies of workers lay down railway lines.

NEW TOWNS

In the factory areas, villages grew into huge towns almost overnight. Workers’ houses were built as cheaply as possible, and often crammed closely together. The industrial towns were dark places, where the air was filled with smoke from the factory chimneys.

INVENTIONS

The driving force of the Industrial Revolution was the rapid development of new ideas, methods, and machinery. Newly invented steam engines were used to power innovative new machines that transformed the mining, textiles, and metalworking industries.

DISEASE

People lived crowded together in the new factory towns. They had no proper sewers, rubbish collection, or clean drinking water. Diseases like cholera, typhus, and typhoid often swept through the towns, killing thousands.

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