My Science School

Archaeopteryx lived around 150 million years ago — during the early Tithonian stage in the late Jurassic Period — in what is now Bavaria, southern Germany. At the time, Europe was an archipelago and was much closer to the equator than it is today, with latitude similar to Florida, providing this basal bird, or "stem-bird," with a fairly warm — though likely dry — climate.

Various specimens of Archaeopteryx showed that it had flight and tail feathers, and the well-preserved "Berlin Specimen" showed the animal also had body plumage that included well-developed "trouser" feathers on the legs. Its body plumage was down-like and fluffy like those of the feathered theropod Sinosauropteryx, and may have even been "hair-like proto-feathers" that resemble the fur on mammals, according to a 2004 article in the journal Comptes Rendus Palevol.

Interestingly, the Archaeopteryx specimens found thus far lack any feathering on the upper neck and head, which may be a result of the preservation process.

Based on its wings and feathers, scientists believe Archaeopteryx likely had some aerodynamic abilities.

A 2018 study published in the journal Nature Communications also found evidence that Archaeopteryx could fly, although not like any bird alive today does. The researchers used synchrotron microtomography — a tool that uses radiation to make magnified, 3D digital reconstructions of an object — to study the Jurassic creature's fossils. Even though Archaeopteryx didn't have the same features in its shoulders that help modern birds fly, its wings looked like those of modern birds that fly, they found.

Credit : Live Science

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Velociraptor retained its feathers, and possibly used them to attract mates, regulate body temperature, protect eggs from the environment or generate thrust and speed while running up inclines.

Velociraptor had a relatively large skull , which was about 9.1 inches (23 centimeters) long, concave on the upper surface and convex on the lower surface, according to a 1999 description of a Velociraptor skull, published in the journal Acta Palaeontologica Polonica. Additionally, its snout was long, narrow and shallow, and made up about 60 percent of the dinosaur's entire skull length.

Velociraptor had 13 to 15 teeth in its upper jaw and 14 to 15 teeth in its lower jaw. These teeth were widely spaced and serrated, though more strongly on the back edge than the front.

Velociraptor's tail of hard, fused bones was inflexible, but likely kept it balanced as it ran, hunted and jumped. 

Velociraptor, like other dromaeosaurids, had two large hand-like appendages with three curved claws. They also had a sickle-shaped talon on the second toe of each foot. 

Credit : Live Science

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Neutron stars can rotate up to at least 60 times per second when born. If they are part of a binary system, they can increase this rotation rate through the accretion of material, to over 600 times per second! 

Neutron stars pack their mass inside a 20-kilometer (12.4 miles) diameter. They are so dense that a single teaspoon would weigh a billion tons — assuming you somehow managed to snag a sample without being captured by the body's strong gravitational pull. On average, gravity on a neutron star is 2 billion times stronger than gravity on Earth. In fact, it's strong enough to significantly bend radiation from the star in a process known as gravitational lensing, allowing astronomers to see some of the back side of the star.

The power from the supernova that birthed it gives the star an extremely quick rotation, causing it to spin several times in a second. Neutron stars can spin as fast as 43,000 times per minute, gradually slowing over time.

If a neutron star is part of a binary system that survived the deadly blast from its supernova (or if it captured a passing companion), things can get even more interesting. If the second star is less massive than the sun, it pulls mass from its companion into a Roche lobe, a balloon-like cloud of material that orbits the neutron star. Companion stars up to 10 times the sun's mass create similar mass transfers that are more unstable and don't last as long.

Stars more than 10 times as massive as the sun transfer material in the form of stellar wind. The material flows along the magnetic poles of the neutron star, creating X-ray pulsations as it is heated.

By 2010, approximately 1,800 pulsars had been identified through radio detection, with another 70 found by gamma-rays. Some pulsars even have planets orbiting them — and some may turn into planets.

Credit : Space.com

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Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the only naked-eye comet that can appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.

The comet is named after English astronomer Edmond Halley, who examined reports of a comet approaching Earth in 1531, 1607 and 1682. He concluded that these three comets were actually the same comet returning over and over again, and predicted the comet would come again in 1758.

Halley didn't live to see the comet's return, but his discovery led to the comet being named after him. (The traditional pronunciation of the name usually rhymes with valley.) Halley's calculations showed that at least some comets orbit the sun.

Further, the first Halley's Comet of the space age — in 1986 — saw several spacecraft approach its vicinity to sample its composition. High-powered telescopes also observed the comet as it swung by Earth.

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Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter, and it's the only dwarf planet located in the inner solar system. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801.

Although it—and the next two asteroids discovered, Pallas and Juno—is located near the distance predicted by Bode’s law for the “missing” planet between Mars and Jupiter, most asteroids found subsequently are not so located, and so the agreement with that “law” appears to be coincidental.

Ceres’ shape and density are consistent with a two-layer model of a rocky core surrounded by a thick ice mantle. Ceres rotates once in 9.1 hours. Compositionally, the asteroid’s surface resembles the carbonaceous chondrite meteorites. Water vapour, the first detected in the asteroid belt, escapes into space when Ceres is closest to the Sun.

Ceres was designated a dwarf planet, a new category of solar system objects defined in August 2006 by the International Astronomical Union. (For a discussion of that decision, see planet.) The U.S. space probe Dawn studied the dwarf planet from March 2015 to November 2018. Dawn observed two very bright spots, Cerealia Facula and Vinalia Faculae, in Occator crater on Ceres.

Credit : Britannica

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Pasteur’s experiments with germs and wine revealed a direct cause-and-effect relationship between bacteria and the souring of wine into vinegar. Subsequently, he invented a process by which bacteria could be killed by heating the wine between 60 and 100° C, then letting it cool. Pasteur completed the first successful test on April 20, 1862, eventually patenting the method we now know as pasteurization, which was soon applied to beer, juice, eggs, and (most famously) milk. This process also proved successful at destroying most yeasts and molds without causing a phase transition in the product.

The temperature and time of pasteurization treatments are determined by the food’s acidity. In acidic foods (pH < 4.6) such as fruit juice, in which pathogens are unable to grow, heat is applied to inactivate enzymes and destroy yeast and lactobacillus. In less acidic foods (pH > 4.6), such as milk, the heat treatments are designed to destroy pathogens, as well as yeast and molds. Both processes extend the product’s shelf life, especially in combination with refrigeration.

Food can be pasteurized in two basic ways: either before or after being packaged into containers. When food is packaged in glass, hot water is used to lower the risk of thermal shock. If packaged in plastic or metal, steam can be used, since the risk of thermal shock is low. In general, most foods requiring pasteurization are liquid (such as milk), and can therefore move through a continuous system comprised of a heating zone, hold tube, and cooling zone, from which the liquid is filled into packaging.

Credit : Smart Sense

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His research, which showed that microorganisms cause both fermentation and disease, supported the germ theory of disease at a time when its validity was still being questioned. In his ongoing quest for disease treatments he created the first vaccines for fowl cholera; anthrax, a major livestock disease that in recent times has been used against humans in germ warfare; and the dreaded rabies.

Pasteur produced vaccines from weakened anthrax bacilli that could indeed protect sheep and other animals. In public demonstrations at Pouilly-le-Fort before crowds of observers, twenty-four sheep, one goat, and six cows were subjected to a two-part course of inoculations with the new vaccine, on May 5, 1881, and again on May 17. Meanwhile a control group of twenty-four sheep, one goat, and four cows remained unvaccinated. On May 31 all the animals were inoculated with virulent anthrax bacilli, and two days later, on June 2, the crowd reassembled. Pasteur and his collaborators arrived to great applause. The effects of the vaccine were undeniable: the vaccinated animals were all alive. Of the control animals all the sheep were dead except three wobbly individuals who died by the end of the day, and the four unprotected cows were swollen and feverish. The single goat had expired too.

As with other infectious diseases, rabies could be injected into other species and attenuated. Attenuation of rabies was first achieved in monkeys and later in rabbits. Meeting with success in protecting dogs, even those already bitten by a rabid animal, on July 6, 1885, Pasteur agreed with some reluctance to treat his first human patient, Joseph Meister, a nine-year-old who was otherwise doomed to a near-certain death. Success in this case and thousands of others convinced a grateful public throughout the world to make contributions to the Institut Pasteur. It was officially opened in 1888 and continues as one of the premier institutions of biomedical research in the world. Its tradition of discovering and producing vaccines is carried on today by the pharmaceutical company Sanofi Pasteur.

Credit : Science History

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Louis Pasteur was a French chemist and microbiologist, known for his pioneering work in pasteurisation and microbial fermentation. He also discovered that microorganisms cause diseases.

Pasteur was born in 1822, in Dole, France. He was an average student in his early years, but was gifted in drawing and painting. He earned his bachelor of arts degree and bachelor of science degree at the Royal College of Besancon in France.

In 1854 Pasteur was appointed the dean of the science faculty at the University of Lille, where he began a series of studies on alcoholic fermentation. In 1857 Pasteur showed the role played by microorganisms in fermentation process. His work provided support to the germ theory of disease. These researches helped him come up with a simple process called pasteurisation, which involves heating liquid (such as milk) at a controlled temperature for a fixed period of time in order to kill bacteria and moulds present in it, without major chemical alteration. Pasteurisation makes the liquid safe for consumption.

Pasteur's later work on diseases such as chicken cholera contributed to the foundation of immunology. He also developed the first vaccines for anthrax and rabies. His scientific accomplishments earned him France's highest recognition, the Legion of Honour.

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What you need:

A glass, water, paper, sketch pen, a table, a friend

What to do:

1. On the paper, draw two arrows parallel to each other. Make sure the arrows are pointing in the same direction.

2. Now, fill the glass with water and place it on the table.

3. Ask your friend to slowly lower the paper behind the glass so that the second arrow is covered by the glass.

4. You can stand in front of the glass and look through it at the arrow.

What happens?

The direction of the arrow behind the glass is reversed!

Why?

This happens because of a special property of light known as refraction'. Refraction is nothing but the bending of light as it travels from one medium to another. This is different from 'reflection' where light simply bounces back when it hits an obstacle.

Refraction occurs because the molecules of a medium are usually packed closer together than the molecules of plain old air. So the light is unable to stick to a straight path when it enters water or glass or anything denser than air.

When you look at the arrow behind the glass, the light from the arrow first passes from the air to the glass and into the water.

That means it has already bent twice (Air-Glass - Water). Then it comes back out the front of the glass to the air. That's two more bends which are exactly the opposite of the first two (Water - Glass-Air). This opposing refraction is what makes the arrow appear flipped when the light finally makes it to your eyes!

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What you need:

A glass bowl, plastic cling wrap, one teaspoon of raw rice, a metal pan, a metal spoon

What to do:

1. Cover the top of the bowl with the plastic cling film. Make sure the plastic is stretched taut over the bowl.

2. Put the rice grains on the stretched plastic.

3. Hold the metal pan upside down right next to the bowl. They do not need to touch, just being close to each other is enough.

4. Now, the fun part: Start banging the pan with the metal spoon.

What happens?

Even though the bowl and the pan aren't touching, the rice grains on the plastic begin to dance around. If you observe it carefully, you'll see that the rice keeps time with your spoon-beating!

Why?

Sound usually travels in the form of waves. The sound of the clanging metal travels towards the bowl and hits the plastic film. This makes the thin film vibrate and the rice grains start to bounce. Their bobbing is in time to the sound waves hitting the film!

In a similar manner, sound also travels to our eardrum and we experience its vibrations. That's how we hear.

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What you need:

A cola bottle with the label removed, some milk, a teaspoon What to do:

1. Open the cola bottle.

2. Pour three teaspoons of milk into the soda bottle.

3. Cap it tightly and leave undisturbed for 10-12 hours. Keep observing the bottle at intervals.

What happens?

As time passes, the cola gradually gets stripped of colour. Only a milky residue remains at the bottom of the bottle.

Why?

The milk reacts to the soda much like it reacts to lime juice. When you add lime juice to milk, the acid in it curdles the milk making it form solid globs.

Cola-flavoured soda also contains an acid called phosphoric acid that causes the milk to curdle. The phosphoric acid molecules bond with the calcium molecules in the milk. The resulting molecules are dense and hence sink to the bottom of the bottle, taking the entire colour with them.

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