My Science School

Humans have not set foot on the moon for nearly 50 years, but the Apollo moon missions aren’t over. The echoes from Neil Armstrong’s first steps are still helping scientists make giant leaps in understanding the moon’s geology.

When Apollo 17 packed up for home in 1972, the astronauts brought rock samples with them. NASA locked many of the rocks and core samples away in a vault, awaiting technological innovations that would allow future scientists to study them better than 1970s technology allowed.

Now, Purdue University scientists including Michelle Thompson, an assistant professor of Earth, Atmospheric and Planetary Sciences in Purdue’s College of Science, and Marc Caffee, professor of physics and astronomy with a courtesy appointment in the Department of Earth, Atmospheric, and Planetary Sciences, are both working on teams that will analyze some of the moon rocks and lunar soil samples from that mission.

Thompson and her team are partnering with some of the original scientists, including Harrison “Jack” Schmitt, the first and only geologist ever to walk on the moon, to learn more about the moon itself through the rock samples.

Credit : Purdue 

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Our Milky Way galaxy is a big place. Even at this blazing speed, it takes the sun approximately 225-250 million years to complete one journey around the galaxy’s center.

This amount of time – the time it takes us to orbit the center of the galaxy – is sometimes called a cosmic year.

By the way, in the past when we’ve talked about this subject, people have commented on the difference between the words rotate and revolve. The word revolve means to orbit around another body. Earth revolves (or orbits) around the sun. The sun revolves around the center of the Milky Way galaxy.

On the other hand, rotate means to spin on an axis. The Earth rotates every 24 hours. The sun rotates, but not at a single rate across its surface. The movements of the sunspots indicate that the sun rotates once every 27 days at its equator, but only once in 31 days at its poles.

The planets in our solar system orbit (revolve) around the sun, and the sun orbits (revolves) around the center of the Milky Way galaxy. We take about 225-250 million years to revolve once around the galaxy’s center. This length of time is called a cosmic year.

Credit : Earth Sky 

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Jupiter is the fastest spinning planet in our Solar System rotating on average once in just under 10 hours. That is very fast especially considering how large Jupiter is. This means that Jupiter has the shortest days of all the planets in the Solar System. 

Jupiter is the 5th planet from the sun and it is the biggest of all planets in the solar system. It is a giant gaseous planet and about 2.5 times the size of all planets combined in the solar system. It spins on its axis in the opposite direction as opposed to most planets. Other gas planets include Saturn, Uranus, and Neptune. Jupiter is believed to have a solid core made of rocks. Like most other planets, Jupiter does not have a defined solid surface. As a result of its rotation, the planet has an oblate spheroid shape having a bulge along the equator. The atmosphere of the planet is divided into different bands that vary with the altitude. At the boundaries are great turbulence and storms and the popular one is the Great Red Spot; a giant storm, which was first observed in the 17th century using a telescope. Because the surface of the planet is not solid, the rotational speed around the equator is different from that of its polar areas, and this is why it has a bulge at its equator. The rotational speed at the equator of this planet is 28,273 miles per hour. A complete day in Jupiter around the poles is an estimated nine hours and 56 minutes while at the equator it is an estimated nine hours and 50 minutes.

Jupiter is made up of 92% hydrogen and 8% of helium in the volume by gas composition, while by mass, its atmosphere is comprised of about of 75% hydrogen and 25% helium. In comparison to the planet Earth, Jupiter is massive but has low density. Jupiter has three rings around it and other moons, which orbit around it as well. The planet has faint narrow rings, which are dark and made of dust and rock fragments. Unlike the rings of Saturn, the rings of Jupiter are constantly losing materials and being replenished with the dust from other tiny meteors hitting the four inner moons. Jupiter has about 69 moons, which include four large moons that were discovered in 1610 by Galileo and they are known as Galilean moons. The largest of the four moons is the Ganymede, which has a larger diameter than planet Mercury. The Jupiter’s rings have three sections namely halo, main, and Gossamer rings.

Credit : World Atlas 

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Moons — also called natural satellites — come in many shapes, sizes and types. They are generally solid bodies, and few have atmospheres. Most planetary moons probably formed from the discs of gas and dust circulating around planets in the early solar system.

Earth's Moon probably formed when a large body about the size of Mars collided with Earth, ejecting a lot of material from our planet into orbit. Debris from the early Earth and the impacting body accumulated to form the Moon approximately 4.5 billion years ago (the age of the oldest collected lunar rocks). Twelve American astronauts landed on the Moon during NASA's Apollo program from 1969 to 1972, studying the Moon and bringing back rock samples.

Usually the term moon brings to mind a spherical object, like Earth's Moon. The two moons of Mars, Phobos and Deimos, are different. While both have nearly circular orbits and travel close to the plane of the planet's equator, they are lumpy and dark. Phobos is slowly drawing closer to Mars and could crash into the planet in 40 or 50 million years. Or the planet's gravity might break Phobos apart, creating a thin ring around Mars.

Credit : NASA Science 

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China and Russia have agreed to jointly build a research station on or around the moon, setting the stage for a new space race.

The United States and the Soviet Union, followed by its successor state, Russia, have long dominated space exploration, putting the first astronauts in space and on the moon and later collaborating on the International Space Station that has been in orbit for two decades.

The joint announcement by China and Russia on Tuesday has the potential to scramble the geopolitics of space exploration, once again setting up competing programs and goals for the scientific and, potentially, commercial exploitation of the moon. This time, though, the main players will be the United States and China, with Russia as a supporting player.

In recent years, China has made huge advances in space exploration, putting its own astronauts in orbit and sending probes to the moon and to Mars. It has effectively drafted Russia as a partner in missions that it has already planned, outpacing a Russian program that has stalled in recent years.

Credit : The New York Times 

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Semmelweis observed that, among women in the first division of the clinic, the death rate from childbed fever was two or three times as high as among those in the second division, although the two divisions were identical with the exception that students were taught in the first and midwives in the second. He put forward the thesis that perhaps the students carried something to the patients they examined during labour. The death of a friend from a wound infection incurred during the examination of a woman who died of puerperal infection and the similarity of the findings in the two cases gave support to his reasoning. He concluded that students who came directly from the dissecting room to the maternity ward carried the infection from mothers who had died of the disease to healthy mothers. He ordered the students to wash their hands in a solution of chlorinated lime before each examination.

Under these procedures, the mortality rates in the first division dropped from 18.27 to 1.27 percent, and in March and August of 1848 no woman died in childbirth in his division. The younger medical men in Vienna recognized the significance of Semmelweis’ discovery and gave him all possible assistance. His superior, on the other hand, was critical—not because he wanted to oppose him but because he failed to understand him.

Semmelweis’ doctrine was subsequently accepted by medical science. His influence on the development of knowledge and control of infection was hailed by Joseph Lister, the father of modern antisepsis: “I think with the greatest admiration of him and his achievement and it fills me with joy that at last he is given the respect due to him.”

Credit : Britannica 

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The leading cause of maternal mortality in Europe at that time was puerperal fever – an infection, now known to be caused by the streptococcus bacterium, that killed postpartum women.

Prior to 1823, about 1 in 100 women died in childbirth at the Vienna Hospital. But after a policy change mandated that medical students and obstetricians perform autopsies in addition to their other duties, the mortality rate for new mothers suddenly jumped to 7.5%. What was going on?

Eventually, the Vienna Hospital opened a second obstetrics division, to be staffed entirely by midwives. The older, First Division, to which Semmelweis was assigned, was staffed only by physicians and medical students. Rather quickly it became apparent that the mortality rate in the first division was much higher than the second.

Semmelweis set out to investigate. He examined all the similarities and differences of the two divisions. The only significant difference was that male doctors and medical students delivered in the first division and female midwives in the second.

Credit : The Conversation

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Today, more than ever, we are quite aware of the significance of handwashing in disease prevention. We have Ignaz Semmelweis to thank for introducing this life-saving procedure in the mid-1800s.

Ignaz Semmelweis was an Hungarian physician who discovered the cause of puerperal fever (postpartum fever) and was the first to propose an antiseptic policy for physicians. It involved handwashing before and after each medical examination.

Ignaz Semmelweis was born in Hungary. After receiving his doctor of medicine degree from Vienna in 1844, Semmelweis decided to specialise in obstetrics. He began work at the Vienna Hospital, Austria, in 1846. At the time, the maternal mortality rate in Europe was as high as 25-30%. The leading cause was puerperal fever, an infection of the female reproductive organs, that was killing postpartum women.

Semmelweis noticed that women delivered by physicians had a much higher mortality rate than those delivered by midwives. He concluded that the problem was that physicians were handling corpses during autopsies before attending to pregnant women.

Dr Semmelweis theorised that cadaverous particles - microscopic particles from the corpses-would have transferred from doctors hands to the pregnant women, who would then fall victim to the same disease. In 1847, he directed his colleagues to start cleaning their hands and medical instruments with a chlorinated lime solution before each examination.

No sooner than not, the mortality rates due to puerperal fever began to drop drastically. But his superiors refused to accept his theory and he was met with harsh criticism. In 1855, he was appointed professor of obstetrics at the University of Pest. Despite various publications of results where hand washing reduced mortality to below 1%, Semmelweis' observations were largely dismissed. In 1861, he published a book of his findings in Etiology, Concept and Prophylaxis of Childbed Fever. In 1865, he suffered a breakdown and was taken to a mental health facility, where he died. It was not until two decades later, when Joseph Lister and Louis Pasteur produced more evidence of the germ theory and antiseptic techniques, that the value of hand washing was appreciated.

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What you need:

Two unopened soda cans (club soda or flavoured, both will do: do not use diet sodas), a sink

What to do:

1. Pick up the first can. Shake it vigorously.

2. Hold it over the sink and snap it open. What happens?

3. Take the second can and shake that vigorously too.

4. Now, hold it in the palm of one hand, and using your index finger, tap or flick the can on all sides. Make sure you cover all the walls.

5. Now, open the can.

What happens:

On being opened, the first can swooshes up most of its contents in a foamy fountain. When the second can is opened, after it has been tapped on all sides, there is no foaming. You can actually enjoy the whole soda!

Why?

The fizz in the soda is actually carbon dioxide gas. When cold drinks are manufactured, a lot of carbon dioxide is dissolved in the liquid much more than the liquid can hold at normal atmospheric pressure (that is why cold drinks are also called 'carbonated' drinks). To do so, a large amount of pressure is applied.

When you open a can of soda, some of the carbon dioxide gas escapes but enough remains in the liquid so you get a fizzy taste. This carbon dioxide is visible in the form of bubbles.

When you shake a sealed can of soda, the carbon dioxide bubbles settle on the inner walls of the can. When you open this can you release the pressure inside. That means, the pressure of the can's contents falls rapidly. There is a relationship between the pressure of a gas and its volume (the number of particles/molecules packed in a small space): it was discovered by a scientist named Robert Boyle and is known as Boyle's law. According to this law, at a constant temperature, when the pressure of a gas decreases, its volume increases, and vice-versa.

So, when the pressure of the gas in the can falls, its volume suddenly increases and the bubbles multiply and swooosh! From the walls of the can the bubbles rapidly try to get to its mouth to escape. They push the liquid out too because it is in their way. That's how you get sprayed. That is why, after shaking the can, you need to tap sides. This helps dislodge the carbon dioxide bubbles from the can's walls. Once dislodged, they settle on the top of the liquid (because a gas is usually lighter than a liquid). That way, when you open the can, the carbon dioxide escapes comfortably. There is no liquid obstructing its way which means clean clothes for us, yay!

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What you need:

A small plastic glass, two drinking straws, scissors, three paperclips and a drawing pin, two small candles that can fit into the straw, a matchbox a newspaper, a ruler

What to do:

1. Place a newspaper or mat on a table (something you don't mind getting wax on).

2. Poke a hole through the bottom of the plastic glass using the scissors. Make the hole big enough so that the straw just passes through it.

3. Place the glass upside down on the newspaper and stick the straw through it like a flag post.

4. Measure the length of the second straw using the ruler and mark its centre. Poke a hole right through the centre using the drawing pin.

5. Unfold one of the paperclips as shown in the picture. Slide the open end of the clip through the holes you have just made in the straw. Rest the straw at the base of the bend.

6. Push the bent side of the clip into the first straw that is sticking out through the glass. Both the straws should look like a seesaw now.

7. Insert a candle (the wickless end) into each end of the second straw and use paperclips to hold them in place. Balance the seesaw by sliding the candles in or out of the second straw to equalize their weight.

8. Light one candle. Wait for a few seconds and then light the other one.

What happens:

Once both candles are lit, the candles start moving up and down in a seesaw swing. Gradually, this swing changes into a twirl and the candles begin to rotate.

Why?

In a normal playground seesaw, you use your legs to move yourself up and your weight to push yourself down. In case of the poor leg-less candles, their wax does the work for them.

Since you have lit one candle before the other, it starts to drip first, shedding wax. As the wax falls off that candle's weight reduces and it rises up. Then, you light the second candle. Since this candle is angled downwards, its wax drips faster and it becomes lighter quicker. That means, it moves up. As the candles drip and shed wax they keep moving up and down according to the difference in their weights. Gradually, the swinging motion of the candles increases so much that they start rotating.

Had you lit both the candles at the exact same time, there would have been no seesawing because both candles would have lost wax at the same rate.

Picture Credit : Google

What you need:

A cloth rag, two glasses, a plate, string, scissors, washing soda, hot water

What to do:

1. Fill the two glasses with hot water. Add about half a cup of washing soda into each glass. Keep the glasses on a table or on the floor.

2. Fold the rag diagonally and then roll it up tightly.

3. Cut three equal lengths of string. Tie the rolled-up rag at the centre and the sides using the string.

4. Trim off the extra length of the string.

5. Place either end of the rag into a glass. Lower the centre of the rag so that it dips downwards.

6. Place the plate underneath this dip and leave the set-up undisturbed for three to five days. Keep observing it.

What happens:

Gradually, a stalactite of washing soda is formed. It hangs from the dip in the rag and reaches the plate underneath!

Why?

First, washing soda is added to hot water which is more accepting than cold water so you can dissolve an excess of washing soda in the water while it's hot

This washing soda solution travels up the cloth through a process called 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, narrow spaces or capillanes are present in the cloth they absorb water and pull it upward

This happens until the cloth gets so full of the solution that it cannot hold any more. That's when the extra washing soda starts dripping from the doth onto the plate As the water cools, it cannot keep the excess washing soda dissolved and deposits it on the rag or on the plate, giving you a soda pillar!

Picture Credit : Google

What you need:

A strong magnet (the stronger the better), a Ziploc bag, any breakfast cereal that claims to have iron in it, water

What to do:

1. Put one cup of cereal in the Ziploc bag.

2. Pour warm water over it. The water should only fill about half the bag so there is an air pocket inside.

3. Seal the bag and mix its contents by shaking it around for a minute.

4. Let the mixture sit for an hour so that the cereal becomes soggy and dissolves in the water.

5. Place the magnet in one palm and place the bag over it. Put your other hand on top of the bag. Now, swivel the bag around for a minute.

6. Turn the bag over so that the magnet is now on top. The liquid falls to the base of the bag and in the air pocket, you can see what the magnet is holding up.

What happens:

Small shavings are stuck to the magnet through the bag.

If this doesn't happen for you, look for a stronger magnet or a different brand of cereal.

Why?

Many breakfast cereals are fortified which means they contain added vitamins and minerals that our body needs. These minerals include iron. Our body needs iron but cannot produce it. So it absorbs what it needs from the food we eat. Natural foods such as legumes, nuts, eggs and meat contain iron. To make cereals nutritious, manufacturers add food-grade iron to them. The quantity of this iron is very small which is why you need such a strong magnet to find it!

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Stars do not really twinkle, they just appear to twinkle when seen from Earth, because of our atmosphere. When light from the faraway stars enters the Earth's atmosphere, its path is affected by air movement, temperature and the density of various layers in the atmosphere. This causes the light from the stars to refract multiple times before reaching us, making the stars look as if they were blinking.

Planets shine more steadily because … they’re closer to Earth and so appear not as pinpoints, but as tiny disks in our sky. You can see planets as disks if you looked through a telescope, while stars remain pinpoints. The light from these little disks is also refracted by Earth’s atmosphere, as it travels toward our eyes. But – while the light from one edge of a planet’s disk might be forced to “zig” one way – light from the opposite edge of the disk might be “zagging” in an opposite way. The zigs and zags of light from a planetary disk cancel each other out, and that’s why planets appear to shine steadily.

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Pedro Bernardinelli spotted the comet that now bears his name just a week or so before he had to defend his dissertation. His doctoral thesis focussed on identifying trans-Neptunian objects (TNOS) - rocks that circle the sun beyond Neptune's orbit.

While this has nothing to do with comets, his analysis using data called the Dark Energy Survey put him onto this particular comet. After he had ensured that it wasn't an anomaly or fault on his part, he took the find to his advisor Gary Bernstein. An astronomer at the University of Pennsylvania, Bernstein's scientific interest lies in looking for distortions that are caused by dark matter.

Size and activity

And so it happened that Bernardinelli and Bernstein discovered a celestial body that is now known as Comet Bernardinelli-Bernstein. While the discovery first excited scientists for the comet's estimated size (100 to 200 km wide), increased observations invalidated the initial estimate. Regardless of the size, scientists have only spotted very few comets active so far from the sun.

Irrespective of size and activity, the most exciting aspect of the discovery of Comet Bernardinelli-Bemstein now is the fact that scientists will be able to study it for extended durations.

Decades-long look

Apart from the fact that this comet, which was discovered in 2021, will have its closest approach in 2031, there are also old observations about this comet from as early as 2010. This means that scientists can literally have a decades-long look at this object, something that is quite rare for comets that make long journeys.

As for Berardinelli and Bernstein, the discovery has brought them unexpected fame in an unrelated field. While Bernstein is pretty clear that he will stick with cosmology. Bernardinelli hasn't ruled out changing his scientific trajectory to include actively studying comets as well.

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The Kitti’s hog-nosed bat (Craseonycteris thonglongyai), sometimes referred to as the bumblebee bat due to its diminutive size, was discovered in 1970s and could arguably be the world’s smallest mammal, depending on how size is defined.

C. thonglongyai is listed as vulnerable by the IUCN and is found in western Thailand and southeast Burma, in limestone caves along rivers. It is the only existing member of the family Craseonycteridae. Its coat is reddish-brown or gray, with a distinctive pig-like snout. Colonies vary in size, but most have an average of 100 individuals per cave. Some caves will have smaller groups from 10 to 15, while others will have up to 500. The bat feeds in short bursts of activity during evenings and dawn, foraging for insects. Its wings seem to be adapted for hovering flight.

The status in Burma is not well known, but the population in Thailand is restricted to a single province and may be at risk for extinction. The principal threats to its survival are mostly anthropogenic, including habitat degradation and the disturbance of roosting sites.

The bat is about 29 to 33 mm (1.1? to 1.3?) in length and weighs 2 g (0.074 oz). Some small shrews, including the Etruscan shrew (Suncus etruscus), may be lighter but they are longer. C. thonglongyai‘s closest relatives are bats from the families Hipposideridae and Rhinopomatidae.

There’s much about C. thonglongyai that remains unknown. Scientists know little about their reproductive behavior, or how they evade predators. It’s also unknown whether colonies stay in one cave or move around to others. This bat does use echolocation.

Credit : Sci-tech Daily 

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