My Science School

The wire that fenced countries, people and wildlife

Did you know that the U.S Patent Office had to process over 200 different patents for various types of spiked dancing in the period between 1867-1874? The barbed wire, as we know it now, really picked up only after an American farmer, Joseph Glidden, received his patent for a way to mechanically produce them (previous versions were hand-made) in 1874.

Uses remain same

Ever since they have been mass-produced, however, they have found uses across the globe. Their biggest use hasn’t change from the time were invented, as the primary goal still remains to fence in cattle. People, however, are not only fencing cattle, but also horses, goats, sheep and even exotic animals.

Human beings too haven’t been exempt from barbed wire, as the wires have been a tool for oppression and control from the earliest days.

They persist to this day and are widely used in prisons and borders, where they remain a threat to wildlife.

Durability has increased

Even though their usability has remained more or less the same, the wires that are now used to make these barbed fences are more durable than ever due to two main developments. By mixing steel with minute quantities of carbon fibre, manufacturers were able to get high-tensile barbed wire that was more flexible, without compromising on strength.

Secondly, new ways of galvanizing the steel were also looked at recently, to keep off rusting for a longer time. The best barbed wire now available is generally coated in a mixture of 95% aluminium and 5% zinc. While conventional barbed wires last 7-10 years, the zinc-aluminium coated ones are expected to last as long as 50 years!

 

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Wombats, platypus and bilbies are biofluorescent

Do you know what’s common to platypus, wombats, bilbies and eastern barred bandicoots? Correct! They are all Australian animals and are nocturnal creatures. And we now know they are all also bioflourecent, that is, their fur glows under ultraviolet light.

Biofluorescene is the phenomenon whereby a substance, such as fur, absorbs light at one wavelength and emits it at a different wavelength. Common biofluorescent hues include green, red, orange, and blue. In just the last few years, scientists have discovered that several animals, including chameleons, corals, jellyfish, reef fish, sharks, scorpions, butterflies, sea turtles and even flying squirrels are biofluorescent. Though the reasons are unknown, theories include camouflage or communication between individuals of the same species.

The current discovery goes back to 2019, when scientists at Northland College in Ashland Wisconsin, found that flying squirrels emitted a pink glow under UV lights. Out of curiosity, they shone the UV light on platypus and other Australian animals. To their surprise, all of them lit up in different hues. They don’t know exactly why the fur glows.

Did you know?

Bioluminescence is another naturally occurring phenomenon, where organisms emit light due to a chemical reaction. It is observed in 76% of all marine life such as jellyfish, and a handful of terrestrial creatures such as glow worm.

 

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Researches from the University of Wisconsin-Madison have discovered a whitish granular coating of high-magnesium calcite on the exoskeleton of leaf-cutter ants. Although common among crustaceans such as crabs, calcareous anatomical structure serving as a protective power is previously unknown in the insect world. Leafcutter ants are indeed tough insects. These they chew up the leaves to feed underground fungus farms on which they sustain. Scientists aren’t sure why the ants needed protection enough to evolve their own natural body armour. They theorise that it could serve as an armour. They theorise that it could serve as an armour when encountering predators or to safeguard them from diseases. The researchers found that the ants are not born with the coating, rather develop it rapidly as they mature, and it significantly hardens the exoskeleton.

Did you know?

Calcite with high levels of magnesium is also found in the teeth of sea urchin, which help them chomp through just about anything. Sea urchins have five teeth, each held by a separate jaw in a circular arrangements at the centre of their spiked, spherical bodies. They use their teeth to crunch on brittle starfish, coral reefs, or even rocks.

 

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Anyone who looks at an ogre-faced spider would be dazzled by its huge eyes that allow it to see 2,000 times better than humans do at night. Wait, the best part is yet to come. These arachnids have the incredible ability to hear a diverse range of sounds using their legs.

Spiders don’t have ears, in the conventional sense. Though most of them can feel the vibrations of prey when they get caught in their webs, it’s not considered hearing. Now, new evidence has shown that ogre-faced spiders have nerve-based receptors on their legs, which function like ears. Jumping spiders and fishing spiders are other two spider species that can hear with their legs. But what’s so impressive about ogre-faced spiders is how well they can hear. Ogre-faced spiders are unique in the sense that they can detect both the low-frequency sounds (say 150 hz) and high-frequency sounds (10 khz) even from six feet away.

Scientists at the Cornell University have document that ogre-faced spiders, do not always rely on their excellent eyesight to catch their prey. They use metatarsal sensitivity (sensors at the tip of the leg) to detect sound cues of even those insects flying behind them with precision. They have recorded that within a split-second, these long-legged spiders make a ninja-like backflip to cast a net on a airborne insect.

Did you know?

Ogre-faced spiders are net-casing nocturnal spiders, found mostly in the southeastern United States. They have a unique way of catching their prey. They make a small web in the form of a net held by the front legs that can be stretched out wide. They cast this net on unwary insects passing by then dine on them.

 

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Gentoo penguins are four species, not one

The gentoo penguin, the third largest penguin species, populates the Antarctic Peninsula and its many islands. It is also found in Falkland Islands and South Georgia in the southern Atlantic Ocean and Kerguelen Islands in the Indian Ocean. The gentoo penguin was first identified in 1781 and had been divided into two subspecies. But a recent study has shaken up this long-held categorisaton. Scientists at the Milner Center for Evolution at the University of Bath have recommended that gentoo penguins be reclassified as four separate species, as new evidence show the existence of genetic and physical differences between the penguin populations. The ‘four species’ live in quite different latitudes, have statistical differences in the lengths of their bones, and the sizes and shape of their beaks. They also vary in behavior such as breading and diet. The differences are great enough that the researchers think both recognized ‘subspecies’ should be elevated to their own species, while two new species should also be added.

Did you know?

Gentoo penguins build their nests using a pile of stones arranged in a large circle of diameter up to 25 cm. stones are gifted by the males to the females to woo them. The gifts are jealously guarded and fights over them can become quite nasty.

 

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Even alligators can regrow their tails

We have long known that reptiles such as lizards and geckos have the ability to regrow their lost tails. A new study has found that even alligators , large semi aquatic reptiles belonging to the crocodilian order, have the ability to regenerate this appendage. A team of scientists from Arizona State University and the Louisiana Department of Wildlife and Fisheries found that juvenile alligators can regrow their tails up to nine inches, or up to 18% of their total body length. What surprise the scientists is the findings that the regrown tail exhibit signs of both regeneration and wound healing within the same structure.

Did you know?

The salamander, axolotl, starfish and sea cucumber are some of the other animals that can regenerate lost body parts. While axolotl can regrow tails, skin and almost any other part, starfish can regrow arms that detach from their central disc, and regrow even an entire body from a lost arm!

 

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The Venus transit of 1882 was followed by a pair that occurred in 2004 and 2012. This means that there were no Venus transits in the 20th Century. The 20th Century, however, saw the first successful interplanetary mission conducted by humans. And the target for that mission was… yes, you guessed it right. Venus?

While the beginning of the Space Age is best remembered for the various firsts that were made possible, the failures that went along aren’t often mentioned in the same breath. The lack of success in some missions, however, weren’t out of the ordinary as humanity was venturing into uncharted territories for the first time.

The failures weren’t entirely frowned upon either as even these situations afforded opportunities afforded opportunities to learn. In fact, missions were planned keeping in mind the higher chances of failure and how to best cope with it if it were to happen.

Backup ready

The Americans had a backup strategy that involved building two similar spacecraft. This meant that even if the first one failed, the second one from the identical pair could be deployed at the earliest.

Mariner 1 and Mariner 2 were the first set of such twins in the Mariner series. Each of these spacecraft, which was powered by solar cells but also carried supplemental batteries on board, were 1 m across and 0.36 m thick.

Mariner 1 lifted off on July 22, 1962, but had to be detonated just 293 seconds after launch as it veered off course due to a typo in the computer code guiding it. Despite the fact that Mariner 1 lasted for less than five minutes, Mariner 2 was brought out of storage and launched towards Venus just 36 days later, on August 27.

Number of glitches

Using the Earth and sun as references, the spacecraft was to keep its attitude stable while making its way through space. It wasn’t without incident though, as there were a number of glitches through its flight.

On September 4, a course correction had to be performed to put it back on track. Four days later, cruise science experiments turned off for reasons NASA couldn’t determine. September 29 once again saw a loss of attitude control followed by a quick recovery. One month later, on October 31, there was a partial short circuit to one of the solar panels on the spacecraft. By November 15, this panel completely failed.

The fact that the spacecraft was approaching Venus and hence getting closer to the sun meant that the working solar panel could generate enough power to keep it going. Eighty years on after the last transit of Venus had been observed from Earth, a spacecraft was now getting close to perform a Venus flyby.

Temperatures, dense clouds

Mariner 2 made its closest approach to the planet on December 14, 1962, flying at a distance of 34,854 km from Venus. Having become the first successful interplanetary mission, mariner 2 had its glimpse of Venus, scanning the planet for 42 minutes. Before continuing on its heliocentric orbit around the sun, Mariner 2 gathered data about our neighbouring planet. NASA maintained contact with the spacecraft till January 3, 1963.

The data conveyed by Mariner 2 showed that temperatures across Venus were more or less uniform and that the planet in general was a hothouse. It also revealed that the planet is under high pressure and that the entire Venus is shrouded in a dense cloud layer above the surface.

Even though Mariner 2 enjoyed only modest success in terms of scientific results, it is remembered and honoured for the first it went out and achieved. The mission served as a gateway to many future endeavours that followed, as it opened up space to the human race like never before.

 

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We couldn’t even breathe without the fresh air plants make! And plants do so much else for us, too. They give us vegetables, fruits, cereals, and most of the other foods we eat. Plants also provide us with wood for building houses and making furniture.

People make cloth - such as cotton and linen for clothes, towels, and sheets - from plants. We get paper, rubber, string, and medicines from plants, too.

Plants also give us pleasure. They are nice to look at, touch, and smell.                

• Plants supply food to nearly all terrestrial organisms, including humans. We eat either plants or other organisms that eat plants.


• Plants maintain the atmosphere. They produce oxygen and absorb carbon dioxide during photosynthesis. Oxygen is essential for cellular respiration for all aerobic organisms. It also maintains the ozone layer that helps protect Earth’s life from damaging UV radiation. Removal of carbon dioxide from the atmosphere reduces the greenhouse effect and global warming.


• Plants recycle matter in biogeochemical cycles. For example, through transpiration, plants move enormous amounts of water from the soil to the atmosphere. Plants such as peas host bacteria that fix nitrogen. This makes nitrogen available to all plants, which pass it on to consumers.


• Plants provide many products for human use, such as firewood, timber, fibers, medicines, dyes, pesticides, oils, and rubber.


• Plants create habitats for many organisms. A single tree may provide food and shelter to many species of insects, worms, small mammals, birds, and reptiles.

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Cereals

For years, our ancestors ate the seeds of wild grasses and chewed the roots of wild plants. Then, about 11,000 years ago, people started to grow the crops they liked best. Ever since, we’ve been growing and developing all sorts of plants to feed ourselves and our animals.

You probably eat grass every day! When we think of grass, we usually think of the grass in lawns and fields. But rice, wheat, oats, rye, millet, barley, sorghum, and maize (also called corn) are grasses, too. These grasses are called cereals. And their fruits, the part we eat, are called grains.

Cereals are the most important group of food plants in the world. Without grains, we wouldn’t have bread, breakfast cereals, cakes, rice, or popcorn. Grasses also provide food for the cows and sheep that give us milk, cheese, and meat.

Plants of the Mountain Community

The tallest mountains are covered with snow and ice, but smaller mountains are often covered with grasses, forests, or mosses and other small plants. In deserts, mountaintops may be dry and stony.

A little lower on the mountain, small plants grow close to the ground for warmth and protection from the wind. A little further down is the timber line. Above that line, trees cannot grow. Along the timber line, most trees are small and bent. The timber line, the trees grow taller and make a forest that covers the sides of the mountain.

The alpine lily is one of the tallest alpine plants. Its slender stem can bend in the wind, so it isn’t damaged in storms. Alpine saxifrage grows into a kind of flat cushion. And edelweiss has a way of keeping itself warm. It is covered with a thick layer of white hairs that acts as a coat and keeps the heat in.

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A mountain has many kinds of plant communities.

The top of a very high mountain is always covered with ice and snow. No plants grow there.

A little lower on the mountain, the snow melts in summer and many plants bloom. Some plant-eaters, such as vicunas in South America and yaks in Tibet, live this high on mountains. Small rodents called alpine marmots live there. So do pikas, which are related to the rabbit.

Lower on the mountain, forests grow. In North America and Europe, you can find bears, deer, elk, foxes, and insects at this level. Trout live in the streams. In eastern Africa, mountain gorillas live in cool mountain forests. Plant-eating animals, such as deer, often move up the slopes in summer and down in winter, to be where food is plentiful.

The plants and animals at the foot of the mountain are the same kinds that live in the surrounding countryside, whether it is forest or desert.

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Plants of the Tundra Community

Most of the tundra is a treeless plain. Even during the short period of warmer summer days, a fierce and terrible wind blows over the land. So only tough, sturdy plants that grow close to the ground can live in this community. Birches and willow trees no bigger than bushes grow here and there. But mosses and small flowering plants are the main plants.

The vegetation of the tundra is almost entirely composed of perennial plants, camephytic plants (cushion-like plants) and hemicryptophytic plants (perennial herbaceous plants). Cushion-like plants include Ericaceae and saxifrages, while hemicryptophytic plants include sedges. There are no forest trees at all. Shrubs, birches and willows are few and small, to resist frost and strong winds. Mosses, rushes, graminaceous plants and peat mosses (a type of moss which has adapted very well to live in swampy areas) grow in wet areas, where the land is soaked in water.

In summer, many short-stemmed flowers deck the tundra in bright colours. Because of the cold, plants have a very slow growth cycle: the reindeer moss (Cladonia rangiferina), for instance, takes one year to grow just 1-5 mm taller.

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Far in the north, on the edge of the great sea that surrounds the North Pole, there is a great, flat plain called the tundra. Most of the time, this plain is bare and frozen. For half the year, days there are nearly all dark and sunless.

In the spring, as the days grow longer, the tundra warms up and the ice melts. Water soaks into the ground. Plants burst into bloom! In summer, the tundra is a busy place. Little lemmings and other animals eat leaves, roots, and seeds. They, in turn, are hunted and eaten by animals such as foxes and wolves.

Winter comes suddenly and lasts a long time in the Arctic. The ground freezes. Snow piles up. Most of the animals leave but some stay. Lemmings burrow into the ground and live on seeds they have stored away. Herds of musk oxen move from place to place, scraping with their hoofs to find food beneath the snow.

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Plants of the Desert Community

The plants of the desert come in many shapes, sizes, and colours. But they all have one thing in common. They all have ways to survive with little water.

Some desert plants almost stop living between rains. But when the rains come, the plants burst into life. Then they quickly produce seeds before the next long dry spell.

Some plants, like the barrel cactus, swell up to hold a water supply. Before it rains, the barrel cactus looks like a grey lump. But after the rain falls, it is a fat, green ball. Cactuses like this one store water in their stems.

Many animals would like to eat desert plants to get the water inside them. But most desert plants protect their precious supply of water with thousands of prickly spines. These spines also do another job. They make shadows. A cactus creates its own shade by casting thousands of tiny shadows on itself.

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A desert seems like a tough place for plants to live. There’s little water, and the ground is hard and dry. But many plants and animals survive in deserts.

It doesn’t rain often in a desert. And when it does, the ground dries quickly. So the roots of most desert plants spread far out just below the surface of the ground. The roots can then catch every drop of water that falls. Most desert plants store up all the water they can get.

During the day, the desert looks lifeless. Most desert animals hide where they can escape the sun’s heat - under a rock, underground, or even in a hole in a cactus.

When the sun goes down, a desert quickly cools. Desert rodents look for seeds. Lizards hunt insects. Snakes hunt the rodents and lizards.

It sometimes rains in a desert. When it does, the desert bursts into bloom because there are many seeds in most deserts. But almost all of these plants quickly wither and die as the ground dries again.