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What is a role of Saharan dust on hurricanes? 🌪🌧 Hurricanes, including tropical cyclone rainfall (TCR), are among the most destructive weather phenomena on Earth. 🌡💧Traditionally, sea surface temperature or humidity in the atmosphere were considered as the main factor controlling hurricane precipitation. 🏜❗️Now, scientists believe that Sahara dust plays a leading role on hurricane formation over the ocean, which affects weather in America. ℹ️ Previous studies have found that Saharan dust transport may decline in the future and TCR could increase due to a climate change. ➡️⬅️According to a recent research, dust can however have competing effects on TCR. ✔️A dust particle can make ice clouds form more efficiently in the core of the hurricane, which can produce more precipitation. ✔️Dust can also block solar radiation and cool sea surface temperatures around a storm’s core, which weakens the TCR. At high concentrations, dust shifts from boosting to suppressing rainfall. Subscribe- t.me/askmenow

Could the Sahara be green again and will Africa finally need its “Great Green Wall”? 🟢 Africa’s “Great Green Wall” initiative was launched to hold back the Sahara from expanding southward. 🟢 This year, after an unusual influx of rain, scientists have compared satellite imagery on September 12, 2024 (⬆️upper image), versus the same day in 2023 (⬆️lower image), and have seen that the southern Sahara’s vegetation reached much farther north in 2024. ℹ️ Where the trade winds from each hemisphere meet near the Equator is a low-pressure zone, the intertropical convergence zone (ICZ). 🟢 According to researchers, most climate models suggest that the ICZ is the reason for Africa’s greening and farther northward “green” shifts in this zone could happen more frequently in the next decades. 🟢 So, in the distant future, it is very possible that the Sahara could turn green again and Africa, at least for a certain period of time, won’t need its “Great Green Wall”. Subscribe- t.me/askmenow

When and why was the Sahara green? ✅ Records from ocean sediment show that the Green Sahara happens repeatedly in Earth's history. ✅ Sometime between 11,000 and 5,000 years ago, after the last ice age ended, about 9 mln square kilometers (3.5 mln square miles) of the modern Sahara Desert was a green place with lakes, where animals like elephants, hippos and antelopes feasted on thriving grasses and shrubs. ✅ The Green Sahara, also known as the African Humid Period, was caused by the Earth's constantly changing orbital rotation around its axis, a pattern that repeats itself every 23,000 years, researchers believe. ✅ Right now, the Northern Hemisphere is closest to the sun during the winter months, and during the Green Sahara, the Northern Hemisphere was closest to the sun during the summer. This led to an increase in solar radiation, in other words, heat, heat in summer, and created a low pressure system that ushered moisture from the Atlantic Ocean into the desert. Subscribe- t.me/askmenow

Who left Paleozoic “dumbbells”? All over the world, scientists find dumbbell-shaped fossils in rock outcrops that are called Bifungites and are not fossilized animals but burrows left in an extinct creature’s wake. ⬆️ Most are found in rocks from the Paleozoic era more than 300 million years ago. 🪱 Not long ago, Brazilian paleontologists, exploring the bed of the Sambito River in northeastern Brazil, found imprints of small worms inside Bifungites, indicating that these organisms produced them.⬆️ Researchers suggest that: 📌 the marine worms that made Bifungites belonged to a group called Annulitubus 📌 species in the group lived in the shallow part of the ocean near the shores of prehistoric supercontinents and dug burrows into the seabed. 📌 the Annulitubus worms made these burrows to protect themselves against savage storms or probing predators 📌 the worms potentially wedged themselves into the peculiar bulging or arrow-like ends of the chamber. Subscribe- t.me/askmenow

How does the brain store memories? 🧠 In the brain, the hippocampus region, crucial for learning and memory, records each event in three different forms or “copies”. These ‘”copies” are disseminated among different groups of neurons that arise at various stages during embryonic development. 1️⃣ The early-born neurons ensure the longevity of a memory creating a copy that, although initially weak, strengthens over time. This memory becomes more accessible to the brain long after its formation, allowing the preservation of memories in the long term. 2️⃣ The late-born neurons produce a memory copy that is very strong initially but fades quickly. This memory is easier to modify shortly after formation, allowing new information to be integrated or errors corrected. 3️⃣ The last group of neurons present an interesting compromise – a memory copy that remains stable over time. These 3️⃣ memory copies function together, enhance the brain’s memory dynamics and reinforce its plasticity. Subscribe- t.me/askmenow

Where do the most genetically diverse people on Earth live? 🌍 The most genetically diverse people on Earth live in Africa. Geneticists have discovered more than 3 mln previously undescribed genetic variants among Africans. That diversity has fit well with the fossil evidence that the human species originated in Africa. It is known that when a new species, be it plant or animal, arises and spreads, genetic differences accumulate more in geographic regions where the species has been present longer. The more distant populations represent only a small subset of the genetic variation that arose nearer the center of origin. The claim has even been made that East Africans are more genetically different from West Africans than Europeans are from Asians. According to researchers: ✔️🇳🇦🇿🇦the southwestern coast of Africa-between today’s Namibia and South Africa-may be modern humanity’s homeland ✔️the oldest group in Africa, evolutionarily speaking, may be the San, or Bushmen. Subscribe- t.me/askmenow

How many phase changes of matter are there? 📌 A phase change or phase transition is a change between solid, liquid, gaseous, and sometimes plasma states of matter. 📌 The main factors that cause phase changes are changes in temperature and pressure. At the phase transition the two states of matter have identical free energies and are equally likely to exist. ❗️ There are 8️⃣ phase changes between solids, liquids, gases, and plasma. Melting (Solid→Liquid) Freezing (Liquid→Solid) Vaporization or Evaporation (Liquid→Gas) Condensation (Gas→Liquid) Deposition (Gas→Solid) Sublimation (Solid→Gas) Ionization (Gas→Plasma) Deionization or Recombination (Plasma→Gas) ✍️ A solid can melt into liquid or sublimate into gas. A liquid can freeze into a solid or vaporize into a gas. A gas can deposit into a solid, condense into a liquid, or ionize into plasma. Plasma can deionize or recombine to form a gas. ℹ️ There are additional phase changes in condensed matter physics or metallurgy. Subscribe- t.me/askmenow

states of matter that exist under extreme conditions

What is a state of matter? ✔️ Matter is anything that has mass and takes up space. It consists of subatomic particles, atoms, ions, and compounds. Sometimes these particles are tightly bound and close together, while other times particles are loosely connected…

What is a state of matter? ✔️ Matter is anything that has mass and takes up space. It consists of subatomic particles, atoms, ions, and compounds. Sometimes these particles are tightly bound and close together, while other times particles are loosely connected and widely separated. ✔️ States of matter are forms in which matter exists, they describe the qualities displayed by matter. Basically, the state of matter of a substance depends on how much energy its particles have. ✔️ It’s possible to change the energy of matter by altering its temperature or pressure, causing matter to transition from one state to another. But, when matter changes state, its chemical identity remains the same. For instance, if you take ice, melt it, and then boil it, its state of matter changes, but it’s always water. ✔️ The four fundamental states of matter that are observable in everyday life, but scientists are discovering new states of matter that exist under extreme conditions. Subscribe- t.me/askmenow

How did a prehistoric bird use its teeth? When the first fossil of Longipteryx chaoyangensis was found in 2020, paleontologists thought its toothed beak suggested it ate fish. Scientists initially compared the ancient bird to the contemporary kingfisher because of its similarly-shaped skull and beak, and diet of small fish, but that resemblance turned out to be a red herring. A more recent look inside a specimen’s stomach showed the bird — which lived 120 million years ago in what’s now northeastern China — fed on fruit-like plants. Longipteryx had disproportionately large teeth toward the front of the beak, and the thickness of those teeth’s enamel resembles that of a hyper-carnivore, akin to a meat-eating dinosaur like Allosaurus. Now, scientists suppose that those features weren’t meant for eating, and Longipteryx was using its head as a weapon, just like modern hummingbirds wield their long, narrow beaks as air-born swords to fight off competition for food. Subscribe- t.me/askmenow

How did the largest pterosaurs fly? Pterosaurs were the first vertebrates that evolved powered flight, but it has long been debated whether the largest pterosaurs could fly at all. Scientists were lucky to find in Jordan three-dimensionally preserved bones of two different large-bodied azhdarchoid pterosaur species. These rare fossils have enabled experts to hypothesize that not only could the largest pterosaurs take to the air, but their flight styles could differ too. Newly collected bones of the already-known giant pterosaur, Arambourgiania philadelphiae, with 10-meter wingspan resemble wing bones of modern vultures, whose flight style is soaring (sustained powered flight requiring launch and maintenance flapping). A new, smaller species Inabtanin alarabia with circa 5-meter wingspan had flight bones that are similar to those of modern flapping birds. it is likely that Inabtanin flew this way (although this does not preclude occasional use of other flight styles too). Subscribe- t.me/askmenow

What was the most spectacular vacuum experiment? 📍 The most spectacular vacuum experiment was performed by a German scientist Otto von Guericke (1602-1686), the inventor of the air pump. In 1654, he evacuated the air from inside a pair of joined metal hemispheres and attached a group of horses to each end. The external air pressure that acted on the hemispheres was so strong that even 30 animals could not pull them apart ⬆️. 📍 The first artificial vacuum was produced in 1643 by an Italian physicist and mathematician Evangelista Torricelli (1608-1647), a pupil of Galileo Galilei (1564-1642). Torricelli used the vacuum in his invention of the mercury barometer. He filled a glass tube (with one end sealed off) with mercury and then immersed it in a basin of the liquid metal. An empty space formed at the upper end of the tube, the size of which varied depending on the air pressure, which led Torricelli to assume that it has to be a void. Subscribe- t.me/askmenow

Can a vacuum be totally empty? 📌 A vacuum is a volume empty of matter, sometimes called ‘free-space’. ❗️ In practice, only partial vacuums are possible. 📌 Outer space can approach the requirements of a vacuum, but even in space there are a few atoms per cubic meter. 📌 Vacuum is not a force. Though the net motion of matter from a region of higher to lower concentration does appear to be due to a force – e.g. inside a vacuum cleaner, gas concentration is about 20% lower than ambient, so air and dust will be ‘sucked’ in. ✍️ Contrary to popular belief, a vacuum cannot be made simply by sucking the molecules out of the container space. Molecules move in every direction and bounce, and to get the molecules out, one needs to wait until they come towards you out of their own ‘free will’, and then ‘bat them’ out of the enclosure using a high speed propeller called a turbo pump. It is often necessary to use more than one type of pump to achieve a reasonably good vacuum! Subscribe- t.me/askmenow

What is the concept of Ahimsa? 🔺 The concept of Ahimsa is an ancient Indian principle of non-violence, non-injury or absence of desire to harm any life forms. 🔺 Ahimsa originated in Jainism, an Indian religion, and is also an important principle in Buddhism, Sikhism, and Hinduism. 🔺 Mahatma Gandhi’s philosophy of non-violence was also profoundly influenced by Ahimsa. ℹ️ 🗓 No wonder that World Compassion Day (WCD), an annual observance held on November 28, originated in India. WCD was founded in 2012 by Pritish Nandy, an Indian poet, journalist, film producer, media and television personality, politician, and activist. While many international days serve as moments of reflection, WCD stands out by inspiring individuals and influential personalities worldwide to act, to speak on their beliefs, aligning non-violence and compassion with the trials and tribulations of the contemporary era. The first WCD was held in Mumbai and was dedicated to animal welfare. Subscribe- t.me/askmenow