My Science School

The term 'oobleck has come from the title of a Dr. Suess book, "Bartholomew and the Oobleck.

In the book, oobleck is a sticky substance that's falling from the sky and taking over an entire kingdom. But can this sticky substance exist outside the story? We can find out, but things can get messy!

What you need:

Corn starch, water, a cup, food or poster colours (optional), a bowl.

What to do:

Measure a cup of cornstarch and toss it into the bowl. Now measure out half a cup of water. Add the colour into the water and mix it.

Pour the water slowly into the bowl. Keep mixing with your other hand (Yes, hand! It has to be messy.).

Once all the water is mixed in, pick up the mixture in your hand and press it into a ball.

What happens?

The mixture turns into a ball in your hand, but once you open your fingers, it slumps into liquid form again!

(If that doesn't happen for you, try adjusting the amount of cornstarch and water.)

Why?

The secret is suspension. The cornstarch doesn't dissolve in the water, its particles just remain suspended if you let the oobleck rest, you'll find that the cornstarch settles down at the bottom of the bowl. Oobleck's behaviour is dependent on pressure. When you squeeze it, you apply pressure which makes the cornstarch particles clump together. When the pressure is released, the cons starch separates again

Sir Isaac Newton, the famous scientist had stated that normal liquids have a fixed thickness and flow. Since the cornstarch goop we made doesn't follow this rule, it is termed as a non-Newtonian fluid. Another example of a non-Newtonian fluid is quicksand.

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What you need:

A plastic cup, yarn or cotton string, paper-clip, thick tissue paper, a nail, scissors and water.

What to do:

1. Cut the string to a length of 20 inches (40 cm). Tie one end to the centre of the paper-clip.

2. Use the nail to punch a hole in the bottom of the cup.

3. Insert the other end of the string through the hole in the cup.

4. Cut the tissue paper into the size of a ten-rupee note. Make it damp using some water.

5. Now fold the tissue paper over the string near the cup. Make sure the string is stretched tight Hold the cup tightly with your other hand and start tugging on the string. Each jerk of the string should make the tissue slide along it

What happens?

You hear a chicken from the cup!

Why?

Sound travels as vibrations through the air. Our ears pick up those vibrations only if they are loud enough.

As you rub the tissue over the string, the friction between them causes the string to vibrate. Without the cup you would not be able to hear the vibrations of the string. But when you add the cup, it collects all those - vibrations and makes them louder. That is called 'amplification and the cup is the amplifier.

It is the same principle that is used by musical instruments such as pianos and guitars. The outer wooden box of the piano is nothing but a sound amplifier.

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What you need:

Wooden toothpicks, a dinner plate, water, dropper

What to do:

1. Take five toothpicks and bend them from the middle in a way that they break but the halves don't separate.

2. Arrange the toothpicks on the plate so that their split centres are touching each other. They should form a closed five-pronged star.

3. Fill the dropper with water. Start putting drops of water over the centre of the star, close to the split parts of the toothpicks. The broken ends need to get soaked.

What happens?

The star 'opens up like magic!

Why?

The water gets absorbed into the wood by 'capillary action. Capillary action is the movement of a liquid against gravity, through narrow spaces. This is the same principle that allows water to be absorbed by a tree's roots and transported to its leaves.

In this case, wooden toothpicks that have been made from trees also have narrow spaces or capillaries in them.

These absorb water along the length of the toothpick and cause it to get swollen.

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McDowell, who is well known in the space community for his research on this topic, has argued that the Kármán line is not based in scientific reasoning. According to his analyses of historical data, Virgin Galactic is right—space begins about 50 miles (80 kilometers) from the ground.

Neither Blue Origin nor Virgin Galactic can put people into orbit around Earth, but the nature of orbits provides a useful way to understand this problem. Imagine you’re a satellite traveling in an elongated orbit around Earth, and your closest approach brings you less than 50 or so miles from the ground. At that point, the atmosphere will assert its presence and drag you down into a fiery plunge. But if your approach takes you above 50 miles, “you will likely survive ’til the next orbit and go around,” McDowell said. At this boundary—which I’m calling the McDowell line—gravitational forces become more important than atmospheric ones.

There are a variety of reasons McDowell argues that 80 kilometers is the clearest boundary of space, such as the scientific measure of the Earth’s atmosphere, the gravitational physics, and the historical precedent — including that Hungarian-American engineer Theodore von Kármán’s original line was closer to 80 than 100.

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Did you know a host of creatures paved the way for human spaceflight? Fruit flies were the first to be sent up in 1947 and they were recovered alive. A couple of years later, Albert II, a rhesus monkey, made it to a height of 134 km, but a problem with the parachute led to his end on landing. Following Albert II, a number of monkeys were sent up but none survived. Their sacrifices helped scientists study the effects of weightlessness and radiation on living beings. The first monkeys to survive the flight into space to a height of over 550km were Able and Baker in 1959.

They flew to a height of 360 miles (580 km) on May 28, 1959 aboard a Jupiter rocket. Their capsule landed 1700 miles (2736 km) downrange from the Eastern Space Missile Center at Cape Canaveral, Florida, and they were successfully recovered. To read more about this historic event, check out our story commemorating the 50th anniversary of the flight.

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Dorothy Hodgkin was an English chemist who determined the structure of penicillin and vitamin B12, for which she won the 1964 Nobel Prize in Chemistry. She also t elucidated the structure of insulin in 1969 after 35 years of work. Her work helped save millions of lives from infection, diabetes and anaemia.

Dorothy Crowfoot Hodgkin was born in Cairo, Egypt, in 1910. to John and Molly Crowfoot who worked in North Africa and the Middle East in colonial administration and later as archaeologists. She studied chemistry at Somerville College. University of Oxford, She was among the first to study the structure of an organic compound by using X-ray crystallography. She went on to do her doctorate under British physicist John Desmond Bemal at the University of Cambridge. She discovered how x-ray crystallography can be used to determine the structure of vitamin D and stomach enzyme pepsin. Dorothy began teaching at Somerville, one of Oxford's few colleges for women. There she established an X-ray laboratory and began working on X-ray photographs of insulin. Working with Australian pathologist Howard Florey and his colleagues at Oxford, Dorothy determined the structure of penicillin, describing the arrangement of its atoms in three dimensions. In the mid1950s Hodgkin discovered the structure of vitamin B12. Her structural studies helped scientists understand how molecules carry out their tasks in living systems.

Hodgkin devoted the latter part of her life to the cause of scientists in developing countries such as India and China. She strived for improved East-West relations and disarmament. She served as the president of the Pugwash Conferences on Science and World Aairs, an organisation that brings together scientists from around the world to discuss peaceful progress towards international security and development.

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Aurora borealis or northern lights near the north pole and aurora australis or southern lights near the south pole are fascinating natural light shows that have captivated human imagination for centuries.

We learnt how these are caused by the burping sun as the electrons emitted this way race through space towards the Earth. When they are funnelled down Earth's magnetic field lines, they go on to collide with oxygen and nitrogen molecules in the upper atmosphere. When these molecules re-radiate the energy thus gained as light, auroras are formed.

Electrons catch Alfven waves

While this much has been well known for a long time now, one mystery about these auroras that has baffled scientists is how exactly these electrons accelerate to extremely high speeds on the last leg of their journey to Earth. Researchers from the University of lowa have found the answer to this question and have published their findings in June 2021.

The scientists have come up with the first direct evidence that the electrons catch a wave, especially Alfven waves (a type of wave that occurs in a plasma as a result of the interaction between the magnetic fields and electric currents within it), that travel Earthward along the magnetic field. lines. By simulating conditions of the Earth's aurora magnetosphere in a chamber and then launching Alfven waves, researchers were able to find out if the electrons inside were affected.

Like a surfer

In the process, they noted that the electrons underwent resonant acceleration by the Alfven wave's electric field. The scientists likened this acceleration to that of a surfer catching a wave and being continuously accelerated while moving along with the wave.

By measuring the resonant acceleration, they were able to show that electrons could reach the speeds necessary for aurora displays. Through their experiments and measurements, scientists have thus proven a theory known as Landau damping that talks about surfing electrons.

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John Dalton, English meteorologist and chemist, a pioneer in the development of modern atomic theory.

The most important of all Dalton's investigations are concerned with the atomic theory in chemistry. While his name is inseparably associated with this theory, the origin of Dalton's atomic theory is not fully understood. The theory may have been suggested to him either by researches on ethylene (olefiant gas) and methane (carburetted hydrogen) or by analysis of nitrous oxide (protoxide of azote) and nitrogen dioxide (deutoxide of azote), both views resting on the authority of Thomas Thomson.

From 1814 to 1819, Irish chemist William Higgins claimed that Dalton had plagiarised his ideas, but Higgins' theory did not address relative atomic mass. However, recent evidence suggests that Dalton's development of thought may have been influenced by the ideas of another Irish chemist Bryan Higgins, who was William's uncle. Bryan believed that an atom was a heavy central particle surrounded by an atmosphere of caloric, the supposed substance of heat at the time. The size of the atom was determined by the diameter of the caloric atmosphere. Based on the evidence, Dalton was aware of Bryan's theory and adopted very similar ideas and language, but he never acknowledged Bryan's anticipation of his caloric model. However, the essential novelty of Dalton's atomic theory is that he provided a method of calculating relative atomic weights for the chemical elements, something that neither Bryan nor William Higgins did; his priority for that crucial step is uncontested.

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Hawking had a rare early-onset, slow-progressing form of motor neurone disease (MND; also known as amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease), a fatal neurodegenerative disease that affects the motor neurones in the brain and spinal cord, which gradually paralysed him over decades.

Hawking had experienced increasing clumsiness during his final year at Oxford, including a fall on some stairs and difficulties when rowing. The problems worsened, and his speech became slightly slurred. His family noticed the changes when he returned home for Christmas, and medical investigations were begun. The MND diagnosis came when Hawking was 21, in 1963. At the time, doctors gave him a life expectancy of two years.

When Hawking first began using a wheelchair in the late 1970s he was using standard motorised models. The earliest surviving example of these chairs was made by BEC Mobility and sold by Christie's in November 2018 for £296,750. Hawking continued to use this type of chair until the early 1990s, at which time his ability to use his hands to drive a wheelchair deteriorated. Hawking used a variety of different chairs from that time, including a DragonMobility Dragon elevating powerchair from 2007, as shown in the April 2008 photo of Hawking attending NASA's 50th anniversary; a Permobil C350 from 2014; and then a Permobil F3 from 2016.

Hawking's speech deteriorated, and by the late 1970s he could be understood by only his family and closest friends. To communicate with others, someone who knew him well would interpret his speech into intelligible speech. Spurred by a dispute with the university over who would pay for the ramp needed for him to enter his workplace, Hawking and his wife campaigned for improved access and support for those with disabilities in Cambridge, including adapted student housing at the university. In general, Hawking had ambivalent feelings about his role as a disability rights champion: while wanting to help others, he also sought to detach himself from his illness and its challenges. His lack of engagement in this area led to some criticism.

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Florence Seibert, in full Florence Barbara Seibert, American scientist, best known for her contributions to the tuberculin test and to safety measures for intravenous drug therapy.

Seibert contracted polio at age three, but became an outstanding student, graduating at the top of her high-school class and winning a scholarship to Goucher College, Towson, Maryland, from which she graduated in 1918. 

While working for the Phipps Institute, Seibert traveled widely, working with such institutions as the University of Uppsala in Sweden. In the mid-1930s her work culminated with her development of the purified protein derivative, or PPD, that would become the basis for what is today known as the Standard TB Test. 

Tuberculosis is a relatively rare bacterial infection that primarily affects the lungs. It can infect and become dormant for months or years, but once detected, it is treatable with a course of antibiotics over several months. Active TB is highly contagious, however and affects less than one percent of the U.S. population. About 500 people die from tuberculosis every year in the U.S. 

Seibert’s breakthrough procedure was readily accepted by the medical community. In 1938 she was awarded the Trudeau Medal from the National Tuberculosis Association for this work. Her TB test became standard in the United States in 1941, and a year later, was adopted by the World Health Organization as well. That year, the American Chemical Society awarded her the Garvan Medal. 

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Cumulus clouds are puffy clouds that sometimes look like pieces of floating cotton. The base of each cloud is often flat and may be only 1000 meters (3300 feet) above the ground. The top of the cloud has rounded towers. When the top of the cumulus resembles the head of a cauliflower, it is called cumulus congestus or towering cumulus. These clouds grow upward, and they can develop into a giant cumulonimbus, which is a thunderstorm cloud.

Cumulus clouds can be formed from water vapour, supercooled water droplets, or ice crystals, depending upon the ambient temperature. They come in many distinct subforms and generally cool the earth by reflecting the incoming solar radiation. Cumulus clouds are part of the larger category of free-convective cumuliform clouds, which include cumulonimbus clouds.

Cumulus clouds form via atmospheric convection as air warmed by the surface begins to rise. As the air rises, the temperature drops (following the lapse rate), causing the relative humidity (RH) to rise. If convection reaches a certain level the RH reaches one hundred percent, and the "wet-adiabatic" phase begins. At this point a positive feedback ensues: since the RH is above 100%, water vapor condenses, releasing latent heat, warming the air and spurring further convection.

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Nimbostratus clouds are produced by nearly thermodynamically stable air motions and are deep enough to allow precipitation particles to grow to the sizes of raindrops and snowflakes.

Nimbostratus clouds are dark gray and thick enough to hide the sun completely. Unlike some other clouds, they don't come in different shapes. You can't look up at a nimbostratus cloud and guess what the shape of the cloud looks like - it just looks flat and gray, like a big cloud blanket over the whole sky.

Nimbostratus occurs along a warm front or occluded front where the slowly rising warm air mass creates nimbostratus along with shallower stratus clouds producing less rain, these clouds being preceded by higher-level clouds such as cirrostratus and altostratus. Often, when an altostratus cloud thickens and descends into lower altitudes, it will become nimbostratus.

Nimbostratus, unlike cumulonimbus, is not associated with thunderstorms, however at an unusually unstable warm front caused as a result of the advancing warm air being hot, humid and unstable, cumulonimbus clouds may be embedded within the usual nimbostratus. Lightning from an embedded cumulonimbus cloud may interact with the nimbostratus but only in the immediate area around it. In this situation with lightning and rain occurring it would be hard to tell which type of cloud was producing the rain from the ground, however cumulonimbus tend to produce larger droplets and more intense downpours. The occurrence of cumulonimbus and nimbostratus together is uncommon, and usually only nimbostratus is found at a warm front.

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Altocumulus clouds are typically found in groups or heaps clumped together. They’re found in the middle layer of the troposphere, lower than cirrocumulus and higher than their cumulus and stratocumulus counterparts. The term mackerel sky is also common to altocumulus (and cirrocumulus) clouds that display a pattern resembling fish scales. Of all the ten different cloud types, you’ll probably find that altocumulus clouds are the one of the most diverse and dynamic in terms of appearance.

These clouds can take on a handful of shapes and sizes. They can include cloud heaps that resemble towering castles (castellanus cloud species), can sometimes resemble a lock of wool (cloud species floccus), can cover the entire sky on occasion (stratiformis cloud species), and can even create horizontal tube-like structured clouds (volutus cloud species).

Altocumulus are also known for creating UFO-shaped clouds (lenticularis cloud species), are responsible for a lot of the fallstreak hole sightings (i.e. hole punch clouds) you might be lucky enough to see (cavum cloud feature), and on the rarest of occasion, can produce a wavy, chaotic appearance (asperitas cloud feature).

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Cirrostratus clouds are high, thin sheet-like thin clouds that usually cover the entire sky. The clouds are so thin that the Sun or moon can sometimes shine through and appear to have a halo as light hits the ice crystals and bends. The halo is the width of your hand held at arm's length. Cirrostratus clouds usually come 12 to 24 hours before a rain or snowstorm.

As a result of slowly rising air, cirrostratus cloud can form. Usually generated at the forefront of frontal weather systems, the movements of cirrostratus can be used to predict what the weather will do in the next 24 hours.

Cirrostratus clouds can also form through contrails, the vapour trails left by planes as they fly through a dry upper troposphere. These streaks can spread out and become cirrus, cirrostratus and cirrocumulus.

Though cirrostratus itself does not produce precipitation, it can indicate whether or not precipitation is likely. If cirrostratus nebulosus exists in the sky it is likely that an incoming warm front will bring persistent rain within a day. If cirrostratus fibratus is spotted, stratus may proceed it, bringing only light drizzle.

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Cirrus clouds are made of ice crystals and look like long, thin, wispy white streamers high in the sky. They are commonly known as "mare's tails" because they are shaped like the tail of a horse. Cirrus clouds are often seen during fair weather. But if they build up larger over time and are followed by cirrostratus clouds, there may be a warm front on the way. 

Cirrus clouds also form in the atmospheres of other planets, including Mars, Jupiter, Saturn, Uranus, and Neptune, and have been seen even on Titan, one of Saturn's larger moons. Some of these extraterrestrial cirrus clouds are composed of ammonia or ices of methane, much as with terrestrial water ice. (The term cirrus also applies to certain interstellar clouds, composed of sub-micrometer-sized grains of dust.

Cirrus comes in four distinct species; Cirrus castellanus, fibratus, spissatus, and uncinus; which are each divided into four varieties: intortus, vertebratus, radiatus, and duplicatus. Cirrus castellanus is a species that has cumuliform tops caused by high-altitude convection rising up from the main cloud body. Cirrus fibratus looks striated and is the most common cirrus species. Cirrus uncinus clouds are hooked and are the form that is usually called mare's tails. Of the varieties, Cirrus intortus has an extremely contorted shape, and cirrus radiatus has large, radial bands of cirrus clouds that stretch across the sky. Kelvin–Helmholtz waves are a form of cirrus intortus that has been twisted into loops by vertical wind shear.

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