My Science School

Rafflesia Arnoldii, or the corpse flower, is the largest individual flower on Earth. It is a species of flowering plant in the parasitic genus Rafflesia found in the rain-forests of Sumatra and Borneo. With a strong and unpleasant odour of decaying flesh, it grows to a diameter of around one metre and weighs up to 11 kilograms. The buds of these flowers are about 30 cm wide and are very large and cabbage- like, in maroon or dark brown colour.

The flower is in fact a pot with five petals with striking red-brick and spotted cream colours, which warmly welcome carrion flies that are hungry for detritus. But the plant is now facing the threat of extinction and its existence is limited to places like Sumatra, Borneo, Thailand and the Philippines, because of depredations caused by humans and its own internal biology.

In terms of survival, everything seems to be against Rafflesia. Firstly, its seeds are difficult to germinate. As a result, it sustains entirely as a parasite on just one type of vine. This is dangerous as it can't survive without the vine. Apart from this, once it has acquired its nutrition by being a parasite, the plant breaks out as a flower bud, swells up over several months, and then bursts into flower. But even after this arduous growth phase, most of the flower buds perish before blooming. Even after blooming, Rafflesia can last only a few days, and is forced to pollinate in this short period of time. But the chances of pollination are very rare as the numbers of plants are decreasing steadily.

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The largest bird on the planet is, rather ironically, the flightless ostrich. It also lays the largest eggs among any living land animal. Ostriches are also the fastest birds on land with an ability to run at 70 kilometres per hour. They are found in the African savanna and desert lands, where they meet most of their water requirements from the plants they eat.

Unlike other birds, ostriches use their wings as "rudders" to help them change direction while running. Their powerful and long legs cover about 3 to 5 metres in a single stride. These legs are also rather formidable weapons. An ostrich kick can kill a human or a potential predator such as a lion! Their feet have long, sharp claws too. Ostriches live in small herds with less than a dozen birds in one herd. They mostly eat plants, roots, and seeds but also consume insects, lizards, and other creatures that are found in this harsh habitat.

Although there is a popular belief that ostriches bury their heads in the sand, this is not true. Perhaps the saying would have originated because of the bird's defensive behaviour. When faced with trouble, ostriches lie low and press their long necks to the ground as a means to become less visible. Since their plumage blends well with sandy soil, from a distance, it gives the impression that they have buried their heads in the sand.

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Blue whales are the biggest animals that have ever inhabited our planet. These marine mammals grow up to 22 metres in length and to a weight of 150,000 kilograms. Their tongues alone weigh as much as an elephant in some cases and their hearts can be as big as an automobile.

The most interesting detail about these huge creatures is the fact that they reach these immense body sizes by consuming tiny shrimp-like animals called krills alone. In some seasons, a single adult blue whale eats about 4000 kilograms of krill a day.

Blue whales belong to the family of baleen whales. Baleen is a fringed plate made of fingernail-like material that is attached to their upper jaws. These giant animals feed by first gulping a great amount of water through their mouth and then they expand the pleated skin on their throat and belly to take it in. After this, the whales use their massive tongue and force the water out through the thin, overlapping baleen plates. This process leaves behind a large volume of krill, which gets consumed by the whales. Blue whales are found in all the oceans, except the Arctic. They occasionally swim in small groups but they move about in pairs or stay alone.

They now face a severe threat due to whaling and are considered endangered according to the IUCN Red List.

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Whale sharks are the largest fish to be identified and can grow up to 10 metres in length. They consume a wide variety of sea animals and planktons in a rather interesting manner. They just keep their mouths wide open and scoop the tiny plants and fishes as they move close to the surface of water.

The whale shark belongs to the category of filter feeders, just like the world's second largest fish, the basking shark. This means that their huge jaws filter everything it comes across, to find its food. This mechanism is similar to that of the baleen whales, where too, a cross-flow filtration is observed. These giants prefer warm waters and are found in all tropical seas. They also migrate to the continental shelf of the central west coast of Australia during the spring season. During this time, the coral spawning of the Ningaloo Reef of this region provides the whale shark with plenty of plankton to feed on.

Although whale sharks are massive, they are very docile. They even allow swimmers to hitch a ride at times! Currently listed as a vulnerable species, these animals face the threat of hunting, as in some parts of Asia, people continue to hunt them.

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Not only can sandstorms damage and bury plants and seedlings, when sand is carried in the wind, the suspended particles trap the Sun’s heat before it can reach the ground. As a result, the air in the area where this sand is deposited or remains suspended becomes warmer and drier. It cannot retain moisture any more. The increase in temperature and decreased precipitation reduce plant growth and result in greater soil erosion, which leads to changes in the landscape.

Sand and dust storms cause significant negative impacts on society, economy and environment at local, regional and global scale.  There are three key factors responsible for the generation of sand and dust storms – strong wind, lack of vegetation and absence of rainfall. The environmental and health hazards of such storms cannot be reduced permanently; however its impact can be reduced by taking appropriate measures.

As the dust cloud rises, it reduces the horizontal visibility which can impact human life in many ways. The fine suspended particles also contain contaminants, bacteria, pollens, which cause negative health impacts such as allergies and respiratory diseases.

Dust also carries airborne pollutants such as toxins, heavy metals, salt, sulphur, and pesticides etc. which cause significant health impacts when people inhale the contaminated dust.  Dust can corrode buildings and other built infrastructure as it contains high level of salts, especially in the GCC countries.

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A butte is an isolated hill with steep sides and a flat top created by the gradual erosion of the earth around by water, wind or ice. The Enchanted Mesa is a sandstone butte in New Mexico where the Acoma tribe lived, until a heavy storm and a landslide destroyed the only access to the peak, forcing them to move elsewhere.

Enchanted Mesa is a sandstone butte in Cibola County, New Mexico, United States, about 2.5 miles (4.0 km) northeast of the pueblo of Acoma. It is called Mesa Encantada in Spanish and Katzimo or Kadzima in Keresan. Acoma tradition says that Enchanted Mesa was the home of the Acoma people until a severe storm and landslide destroyed the only approach. There are no longer any ruins on the flat top. The butte is 430 ft (130 m) high, 1,250 ft (380 m) long and only 400 ft (120 m) ft wide, at its widest. The elevation at the top is 6,643 ft (2,025 m).

In 1892, when Charles F. Lummis was visiting Acoma he listened to the old Indian governor, Martín Valle, who told the story of how the Acoma people used to live on Enchanted Mesa. Their access to the top was on the southern side where a large piece of the butte was said to have spalled off and formed a ramp, a "stone ladder", up to the top. In reality, access was by climbing a ladder in a narrow fissure. Evidence of holes carved into the sandstone on either side of the fissure can be seen, located in the horseshoe shaped bowl at the southern end. The early inhabitants had a precipitous climb up the fissure, but it assured their safety. Into these holes were placed stout lengths of wood, the 'rungs' of the ladder. Today, this is still the only means of climbing access to the top of the mesa. Their fields, and the springs that were their water source, were in the valley. In the summer, the entire village would descend into the valley to tend the crops. One afternoon a severe thunderstorm washed away the "stone ladder", leaving only sheer rock faces all the way around the butte. Legend has it that three old women and a young boy had been left in the village, but they could not get down, nor could anyone else get back to the village. A giant thunderbird swooped down and scooped up the four and carried them to the valley floor. The Acoma people abandoned Enchanted Mesa and moved to White Rock Mesa, now called Acoma.

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When there is lots of loose sand in a desert and the wind blows constantly in one direction, it builds up crescent-shaped sand dunes, whose tips point against the wind. Large barchans can be very wide and very high.

Barchan, also spelled Barkhan, crescent-shaped sand dune produced by the action of wind predominately from one direction. One of the commonest types of dunes, it occurs in sandy deserts all over the world.

Barchans are convex facing the wind, with the horns of the crescent pointing downwind and marking the lateral advancement of the sand. These dunes are markedly asymmetrical in cross section, with a gentle slope facing toward the wind and a much steeper slope, known as the slip face, facing away from the wind. Barchans may be 9–30 m (30–100 feet) high and 370 m (1,214 feet) wide at the base measured perpendicular to the wind. They gradually migrate with the wind as a result of erosion on the windward side and deposition on the leeward side. The rate of migration ranges from about a metre to a hundred metres per year. Barchans usually occur as groups of isolated dunes and may form chains that extend across a plain in the direction of the prevailing wind.

Credit: Britannica

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At 16,570 feet (5,050 meters) in elevation, the Atacama Desert plateau may be the best place in the world to spot the solar system's secrets. To the delight of amateur astronomers, the desert sees as many as 330 cloud-free nights each year. High along the Atacama Desert plateau, an array of observatories track the celestial bodies in our solar system and beyond.

The Atacama Large Millimeter Array/submillimeter (ALMA) — a network of 66 telescopes run by an international collaboration of scientific organizations from Europe, North America, East Asia and the Republic of Chile — spies on faraway stars and the planets birthed around them.

The European Space Observatory's Very Large Telescope, helped spot the TRAPPIST-1 system of Earth-like planets, located a mere 40 light-years from Earth, and has gathered data on distant exoplanet atmospheres. This telescope, along with others, has uncovered some of the universe's most intriguing oddities and provided a wealth of data to researchers and astronomers worldwide.

Credit: LIVE SCIENCE

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A large area full of sand dunes in a sandy desert is called an erg. As they are formed by the wind, it is likely that their shape, or their number, may change over a period of time. A large erg can spread over many kilometres.

An erg is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The word is derived from the Arabic word arq (???), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than 125 km2 (48 sq mi) of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers 9 million square kilometres (3.5×106 sq mi) and contains several ergs, such as the Chech Erg and the Issaouane Erg in Algeria. Approximately 85% of all the Earth's mobile sand is found in ergs that are greater than 32,000 km2 (12,355 sq mi). Ergs are also found on other celestial bodies, such as Venus, Mars, and Saturn's moon Titan.

Credit: Wikipedia

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The Kalahari Desert is not really a desert, but rather a large arid to semi-arid sandy area in southern Africa, covering much of Botswana and parts of Namibia and South Africa. Though it is semi-desert, it has huge tracts of excellent grazing after good rains and is rich in wildlife.

The Kalahari has existed as an inland desert since the Cretaceous period (65-135 million years ago). It has experienced both periods of greater humidity and more aridity, documented in fossil dune fields. It was during a period of greater rainfall that the Makgadikgadi Depression in northern Botswana was formed. The former lake at one point covered 23,000 square miles (60,000 square kilometers), about the same size as Lake Victoria today. The dry riverbeds that now only hold water when it rains are also from such periods.

Credit: New World Encyclopedia

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The Gobi Desert straddles Mongolia’s southern border with China’s autonomous region of Inner Mongolia. It is a cold desert formed in the rain shadow of the Himalayas. The world’s highest mountain chain blocks clouds from the Indian Ocean from making it over the Tibetan Plateau and into the Gobi area.

During the late Cretaceous, some 70-80 million years ago, the Gobi region was a lot different. Parts of it were covered by dense conifer forests, criss-crossed by streams and dotted with lakes. Today, though, thanks to the desert’s barren, rock-strewn landscapes, paleontologists have found so many incredible fossils. The rocks from the lush dinosaur age are already exposed at the surface and ready to be explored.

The first-ever positively identified dinosaur eggs became one of the first sensational finds from a rocky outcrop called the Flaming Cliffs. Andrews thought the eggs belonged to a dinosaur called Protoceratops, a small hornless relative of Triceratops. Intriguingly, in other finds, a feathered carnivorous dinosaur called Oviraptor had also been found fossilized on top of Protoceratops eggs. In the 1990s scientists discovered that the eggs actually belonged to Oviraptor and these fossils were the first known evidence of dinosaur brooding behavior, a further evolutionary link with birds. Sadly, because of scientific naming rules, Oviraptor will always bear the Latin name “egg plunderer”.

Credit: EARTH ARCHIVES

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When a bee stops at a flower to gather nectar and pollen, it contacts the anthers. Pollen from the anthers attaches to hairs on the bee's body. When the bee moves on, it carries that pollen to the stigma of the next flower it visits. This transfer of pollen between flowers results in pollination. Here's a look at two unusual plants that have unique mechanisms to attract other creatures for helping with their pollination

Dish-advantage

Marcgravia evenia, a plant native to Cuba, has bowl-shaped leaves that act as a satellite dish to reflect sound waves emitted by bats. They also enable the plants pollinators the Cuban nectar-feeding bats-to locate the plant easily amidst the surrounding foliage. Researchers believe that the plant has developed the bowl-shaped leaves in addition to its regular leaves because the curved shape reflects sound waves more efficiently. Even though many plant species are pollinated by bats, this is the first instance of a plant evolving special leaves to aid echolocation of bats.

Bizarre appearance

Hydnora africana is a bizarre-looking parasitic plant with no leaves. It lives off the roots of other plants. It grows completely under the ground except for its flower, which usually grows above the ground. The flower is fleshy from inside but hard as wood from the outside and attracts dung and carrion beetles with its strong, fetid smell. As these insect pollinators stop by, they get trapped in the stiff bristles that line the inner portion of the flower. The flower opens out after a while, allowing the insects to escape but only after they have picked up or deposited pollen. Once has taken place, the flower develops into an edible fruit containing over 20,000 seeds. Hydnora africana is native to the arid regions of southern Africa.

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