DO YOU KNOW

Q. Ants don’t get hurt when they fall. Why?

A: The fall of a body is controlled mainly by the gravitational attraction of the earth. The strength of the gravitational force depends on the mass of the falling object. A heavier object is thus “attracted” more than a lighter object. This attractive force is opposed by an upward thrust, or resistance, that is offered by air on the falling body. The strength of the resistance depends among other things on the surface area of the object. If the surface area is greater, so is the resistance. When any object falls through the air, these two forces compete with each other. In the case of an ant, the force of gravity is almost completely balanced by the resistance offered by the air. Thus the ant is able to land safely. In fact, if there is a wind blowing, the ants may just float away. But if a cluster of ants or a sufficiently large ant is forcibly hurled at the ground, they will get hurt. This is how much we know from the laws and theories of physics about how ants fall through the air. Whether the ant actually gets hurt is another question entirely — and probably one that hasn’t been answered so far.

LITTLE STUDS ON JEANS

Rivets

 

The little studs on jeans, also known as "rivets", serve a functional purpose to reinforce and strengthen areas of the jeans that are subject to stress and wear. They are typically found near pockets, belt loops, and other stress points. The rivets prevent the fabric from tearing or fraying over time, especially in areas that experience frequent movement and tension. 

Originally designed in the late 1800s by Levi Strauss to improve the durability of workwear, rivets have become a standard feature in modern jeans. Apart from enhancing the jeans' longevity, rivets add a stylish and distinctive element to the overall design, making them a practical and fashionable addition to denim apparel.

DO YOU KNOW

What is the origin of the term ‘piggybank’?

Nowadays, when you hear the word ‘piggy bank’, you immediately think of an object shaped like a pig, which parents give their children in order to encourage them to save money. Whenever a child receives money from the parents or relatives, they are expected to put it in the little bank. The curious among you may wonder why this ‘bank’ is shaped like a ‘pig’ — after all, this animal, is not known for its ability to save — it never stores food for winter. The only thing it does is eat. As you are probably aware, several centuries ago the dishes and utensils that we make use of today were made of clay, and not metal. In England, the clay that was used to make jugs, jars, plates, etc. was called ‘pygg’. Whenever a housewife managed to save some money, she used to put it in a ‘pygg jar’ which she called ‘pygg bank’ — meaning ‘clay bank’. Around the 18th century the spelling of the clay was changed to ‘pig’, and by the time the 19th century arrived, most people had forgotten that the word ‘pig’ in ‘pig bank’ referred to a type of clay and not the animal. 

DO YOU KNOW

What are crocodile tears?

Crocodile tears is a phrase used to describe fake or insincere expressions of sadness. The term comes from an old myth that crocodiles cry while eating their prey. People once believed that crocodiles wept to lure in their victims or to show false remorse. However, this is not true. 

In reality, crocodiles do produce tears, but not because they are sad. Crocodile tears are a natural part of their body’s function to keep their eyes moist, especially when they are out of water for a long time. When crocodiles eat, their jaw muscles can press on the tear glands, causing them to release tears. This has nothing to do with emotions. 

Today, when someone says you are shedding "crocodile tears", it means they think you are pretending to be sad or sorry when you really are not. It’s a way to call out someone who is being insincere. 

DO YOU KNOW

 What causes albinism?

Albinism occurs if there is little or no melanin pigment in the body.

How is melanin produced in the body?

The skin has special cells called melanocytes. These cells start to produce melanin when stimulated. After the production is completed, melanin is sent to the melanosome. The melanosomes transport melanin to the skin. The more melanin is produced, the darker the skin gets.

Melanin is produced especially on sunny days because it absorbs harmful rays of the sun and protects the body. That's why we tan when the weather is sunny.

As people with albinism cannot produce melanin, they don't tan but they become red. They pay attention to the clothes they wear and use sunscreen to protect their skin.

The primary effect of the melanin deficiency can be seen in the eyes. Albinism causes many eye problems. These problems include crossed eyes, light sensitivity, blurred vision and involuntary eye movements. 

Light sensitivity occurs as follows: The iris, the colored structure in the eye, shrinks when there is too much light and gets bigger when there is less light. The retina absorbs the excess light coming into the eye. The iris of people with albinism cannot shrink when there is too much light and more light enters the eye. The retina cannot absorb all of the light and as a result, light sensitivity occurs.

The eyes of people with albinism look red. It doesn't mean that they have red eyes! It is the reflection of the vessels in their eyes. 

All organs of the people with albinism are healthy except the vision center of their brain.

Some animals only have melanin pigment in their skin. Others have different pigments besides melanin. Lack of melanin causes albinism in animals too.

Animals with albinism have white skin, hair and feathers. Unfortunately, the technology for people with albinism is not applicable for animals in nature. It is difficult for them to camouflage themselves because their skin is white. 

For example, when crocodiles with albinism are born, they attract predators' attention and they are easily hunted. 

It is believed that squirrels with albinism have the most comfortable life compared to other animals with albinism. This is because they move very quickly and hide between the trees!

Can plants have albinism? They can! The pigment named chlorophyll makes the plants green. The lack or absence of chlorophyll pigment in plants causes albinism. Plants that we are used to seeing green appear white.

Plants make their own food thanks to the chlorophyll. You may wonder about the relevance of food to our subject. Plants with albinism cannot make food without chlorophyll. For this reason, it's difficult for them to live. But plants help each other. They transfer food to other plants in need of food through their roots. Plants with albinism hold on to life in this way.

The best examples of them are redwoods. They reach a maximum height of about 20 meters. The location of many of them are kept secret because they are under protection.

DO YOU KNOW

 If atoms make up everything, what makes up atoms? 

Atoms are the basic building blocks of everything. They join, or bond, together to make larger molecules – be that the water you drink or the rocks that make up the Moon. Atoms are made up of three tiny particles: protons, neutrons and electrons. 

The protons and neutrons clump together in a central nucleus, which is orbited by the electrons. The protons and neutrons together give the atom its mass (weight). Protons carry a positive charge and neutrons are neutral. This makes the nucleus positive and keeps the negatively charged electrons attracted to it. 

All the elements (the different substances that make up the universe – hydrogen, carbon, oxygenor iron, for instance) are made up of these same three particles but each element has a unique “recipe”. An atom of the light element helium, for example, has two protons, two neutrons and two electrons. An atom of heavier gold, on the other hand, has 79 protons, 118 neutrons and 79 electrons. 

Protons and neutrons are actually made up of even smaller particles called quarks. There doesn’t seem to be anything smaller inside electrons though, which makes sense as they are 1,800 times smaller than protons and neutrons.

DO YOU KNOW

How are clothes dry-cleaned?

It is a process used by launderers to remove dirt and stains from clothes using little or no water. The method involves the use of liquid solvents. First the clothes are sorted and put into a large machine which resembles the domestic washing machine. It has a rotating drum that is filled with solvents to which is added a detergent. Once the cleaning is done, the solvents are drained out by the rapid spinning of the drum. Then a machine called a tumbler blows warm air through the clothes to dry them up. Later, the clothes are checked to see if stains have been removed. A device called a steam gun is used to spray water on any stain found. Certain chemicals are applied on the wet spot to remove the stain thoroughly.

DID YOU KNOW?

Why do we have accents?

An accent is a way of pronouncing that is particular to a person, location or nation. There are two types. 

The first is the accent you have when you speak a foreign language, having to make words and sounds that you aren’t comfortable with. 

The second is the accent we speak our native language with, such as how the British sound speaking English in comparison to how we sound speaking it. 

To confuse us more, different areas in a country can have different accents too. 

Languages all have different sounds. It appears that as people moved around and started to live in isolated areas, they developed different speech patterns and accents. 

As the world was developed and we went through periods of invasion and settlement, new accents mixed with old. 

There are more than 2,500 spoken languages in the world today. 

DO YOU KNOW

Why does octopus spit ink?

Octopuses, along with other cephalopods, use ink as a defense mechanism to distract or scare predators away so that they can escape. 

The ink is released from ink sacs located between the gills and is made of mucus and melanin. When released, the ink can be dispersed more widely if the octopus also uses a jet of water from its siphon. 

Some octopuses can even eject ink in thick spurts that look like their own body shape. 

INTERESTING FACTS

About India's Independence Day

Every year the whole nation of India fathoms the patriotic feeling with the tricolor of saffron, white and green on 15 August, which is celebrated as the Independence Day in India.

Here are some interesting facts about India’s Independence day:

● India had no national anthem when it became an independent country on 15th August, 1947. It was adopted as India’s national anthem later in the 1950s. The Bengali version of Jana Gana Mana was written by Rabindranath Tagore in 1911 which was first sung during the Calcutta session of the Indian National Congress.

● Although India became independent on July 18, 1947, Lord Mountbatten declared 15th August as the date of Independence because this date observed the second anniversary of the surrendering of Japan to the Allied Forces during World War II.

● The National Flag was first hoisted at the Parsee Bagan Square in Calcutta on August 7, 1906. The flag had three horizontal strips of red, yellow and green color. The red strip at the top consisted of 8 white lotuses imprinted on the flag in a line. On the yellow strip, Vande Mataram was written in Hindi. There was a white sun on the left and a white crescent and star on the right imprinted on the green strip.

● The first variant of the national flag was designed by Pingali Venkayya in 1921. It consisted of two colors-red and green which represented the two significant communities. But Gandhiji later recommended to add a white strip in the middle with a spinning wheel. The white color represented the remaining Indian communities and the spinning wheel signified the progress of the country.

● Our country got its name ‘India’ from the River Indus, a place which was a home to the country’s first inhabitants.

● No country had ever been invaded by India in the last thousand centuries of its history.

● India shares its Independence Day with five more countries on August 15, but with different years. The countries are Bahrain, North Korea, South Korea, Congo, and Liechtenstein.

● Even after India became independent in 1947, Goa still remained a Portuguese colony. Portugal made amendments in its constitution stating Goa as a Portuguese state. It was made a part of India in 1961 after Indian troops annexed the state to India.

● The Khadi Development and Village Industries Commission is the only licenced company engaged in the production and supply of Indian flag. The Karnataka Khadi Gramodyog Samyukta Sangha located in Dharwad is the only manufacturer of the flag made with cotton.

● Pandit Jawaharlal Nehru, India’s first Prime Minister, featured on the famous Vogue magazine because of his unique dressing sense. His jacket became a popular fashion trend in the West and came to be known as the ‘Nehru jacket’.

● Mahatma Gandhi was absent from the celebrations of the country’s first Independence Day. He was there to be a part of a hunger strike that was conducted to impede the communal killings that were triggered due to partition.

● There was a controversy relating to the Indian national anthem, Jana Gana Mana that it was written by Rabindranath Tagore for the British emperor. He refused these claims on the basis that the song talked about the victory of Bhagya Vidhata of India and not of the British king.

● The price of 10 grams of gold was Rs 88.62 at the time of independence.

DID YOU KNOW

Where did the word 'moon' come from?

Earth has just one moon. It is best known as the Moon in the English-speaking world because people in ancient times used the Moon to measure the passing of the months. The word 'moon' can be traced to the word mona, an old English word from mediaeval times. Mona shares its origins with the Latin words metri, which means to measure, and mensis, which means month. So we see that the Moon is called the Moon because it is used to measure the months. But why do the moons around other planets have names, while ours is just the Moon?

When the Moon was named, people only knew about our Moon. That all changed in 1610 when an Italian astronomer Galileo Galilei discovered what we now know are the four largest moons of Jupiter. Other astronomers across Europe discovered five moons around Saturn during the 1600s. These objects became known as moons because they were close to their planets, just as our own Moon is close to Earth. It’s fair to say that other moons are named after our own Moon. The newly discovered moons were each given beautiful names to identify them among the growing number of planets and moons astronomers were finding in the Solar System. 

INVENTION

Parachute 

The word parachute comes from the French words 'para' and 'chute'. Used together, they mean 'to shield a fall'. Parachutes had been first imagined and sketched by Leonardo da Vinci. They were reinvented in 1783 by a French chemist, Louis Lenormand, who was also the first to make a parachute jump. 

The material of the parachute has changed a lot since it was invented. But the basic design was not changed until the 1930s. Originally made from canvas, parachutes were later fashioned from silk. 

Today, parachutes are made from 'rip-stop' nylon that is woven with extra thick thread at regular intervals, creating a pattern of small squares. These squares keep small tears from spreading. 

DO YOU KNOW

Who controls the internet?

The internet is a decentralised global network owned and managed by governments, private companies, non-profit organisations and individual users. It is not controlled by any single entity. The internet's technical infrastructure is maintained by organisations like ICANN for domain names and IP addresses and RIRs for IP address allocation. ISPs provide internet access. 

Internet governance involves multiple organisations and entities globally and nationally. The IGF facilitates policy discussions, while governments and regulatory authorities have jurisdiction over internet-related matters within their territories. However countries may have varying levels of control and regulations over internet access and content. Some impose censorship and surveillance. In summary, the internet is a complex network with a collaborative governance structure involving numerous stakeholders. While decentralised,  individual countries have different degrees of control and regulations over their Internet environments. 

DO YOU KNOW

 What happens when you sneeze?

Sneezing is your body’s way of expelling foreign matter such as dust, pollen or smoke from the nostrils to prevent them from travelling to the lungs and causing harm. When the delicate lining of your nose detects one of these contaminants it instantly sends an electrical signal to the brain. 

The brain sends signals to all the parts ofthe body that are needed to help you sneeze. Your chest muscles, diaphragm, abdominals, vocal cords and the muscles in the back of your throat all work together to help expel the irritant. 

In most cases, your eyes are forced shut, the tongue moves to the roof of the mouth and the muscles brace for the sneeze. 

Sneezing pushes water, mucus, and air from your nose with an incredible force and in the process the foreign matter is removed.

SCARY MYTHICAL CREATURES

Vampires

Have you ever wondered where the myth of the vampire originated? Why did so many people believe that such a scary creature really existed? Why are we so fascinated by these monsters today?

What is a vampire?

Vampires are mythical creatures that usually feed on the blood of living creatures (eeuw!). Vampires were originally described as bloated and ruddy. The pale and gaunt version of today only appeared in literature in the 1800s.

In fact, the term ‘vampire’ was not popularly used until the 18th century after there was an influx of vampire superstition into Western Europe from areas like the Balkans and Eastern Europe where vampire legends were popular.

Vampires in literature

Literature had and still has a huge influence on the vampire myth. The charismatic and sophisticated vampire of modern fiction was born in 1819 with the publication of The Vampyre by John Polidori. Bram Stoker’s Dracula, written in 1897, is thought of as the most important vampire novel. It provides all the basics for the modern vampire legend. The massive success of this book started the vampire genre which is still popular today. Think Twilight, for example, although some literary snobs will pull up their noses at the mere mention of it…

How to become a vampire

In modern mythology, the way to become a vampire is to be bitten by a vampire (ouch!). The original ways to become a vampire were even more ridiculous. A dead body was feared to become a vampire if a dog or cat jumped over it. A body with a wound not treated with boiling water was also believed to become a vampire. Doesn’t that sound silly?

Vampires do not make good friends

Vampires were believed to bring misfortune or death to family members or close neighbours. So people who knew the person before they became a vampire would be thought of as being in danger.

Vampire defense 101

According to legend, vampires can be warded off by garlic, a branch of wild rose and hawthorn, or by sprinkling mustard seeds on the roof of your home. A vampire would be forced to spend all night counting the seeds. 

Sacred items such as a crucifix, rosary or holy water were also believed to keep vampires at bay. Vampires are not able to walk on holy ground, such as churches and temples, nor are they able to cross running water. 

Some traditions claim that vampires cannot enter a house unless invited by the owner, but once invited, they could return at anytime.

Vampires are also vulnerable to sunlight so are mainly active during the night.

A proven myth 

In the 18th century the vampire controversy raged on for many generations. Many people believed in vampires and many people were accused of vampirism. People often dug up graves to make sure that the bodies were actually dead (gross!). Empress Maria Therese of Austria sent out her personal physician to investigate claims of vampires. When the doctor concluded that vampires did not exist, the empress passed a law that stopped people from opening graves. This ended the vampire ‘epidemic’. What a relief!

Popular theories:disease and other things

A popular theory as to why people believed in vampires is because they did not know what happens to a body after death. 

Another theory relates to outbreaks of illnesses, such as TB and a form of the bubonic plague, which would infect a family or small community. The illness would take the life of one member of the community, and others would become sick. The lack of understanding of how disease spread caused people to believe that a vampire was the cause of the misfortune.

The most likely disease to have caused the vampire legend is rabies. Vampires were thought to be able to turn themselves into bats and wolves. Bats and wolves are sometimes carriers of rabies. They could spread the disease among humans. Many of the symptoms of rabies are similar to that of identifying a vampire. People affected by rabies are very sensitive to garlic and strong light. The disease can also lead to sleep disturbance, where the person suddenly becomes nocturnal. According to legend, a rabid man cannot look at himself in the mirror. This led to rumours that vampires have no reflections.

Modern medicine has come a long way since then. A doctor can easily tell if a person is ill. No one need sprinkle mustard seeds on the roof to keep the sick person away!

Vampires in pop culture

Today, there are many films and books about vampires, and not all of them are scary monsters. Count Von Count from Sesame Street is a lovable vampire who loves to count (and not just mustard seeds!). Ernest the vampire is a sweet vampire, who lives alone in a big castle, is easily frightened by his nightmares, and has a hard time keeping his pants from falling down!

The next time you are afraid of the dark, just remember that vampires only exist in our imaginations.

DO YOU KNOW

How does a seat belt help a car passenger in the event of an accident?

When a car is in motion, the passengers seating in it are also moving at the same speed. If the car is moving at a speed of 70kmph (kilometres per hour), for example, the passengers are also moving at the same speed though they are not aware of it. 

Now, if the car crashes, its speed rapidly changes from 70kmph to 0kmph. The passengers are still moving at 70kmph at the time of impact, in accordance with Newton's first law of motion which states that "a body in motion tends to keep moving until an external force is applied to stop it".

An external force has stopped the motion of the car but not that of the passengers. They will hurtle forward at 70kmph and hit the dashboard or crash through the windshield. But not if they're wearing seat belts. 

Firstly, a seat belt, being slightly elastic, stretches to slow down the abrupt halt of the passenger. It also secures the passenger to the seat thereby stopping him/her from being thrown forward. Thirdly, it spreads the force of impact over the stronger parts of the body like the lap (pelvis) rib cage and shoulders. 

So wearing a seat belt can prevent grievous hurt or even death, in an accident. 

DO YOU KNOW

Why do our stomachs sometimes rumble?

When we haven’t eaten for a while, our stomach is nearly empty, containing only gastric juices and swallowed air. The normally quiet and slow movements of the stomach walls become stronger, causing a gurgling sound known as hunger contractions. These sounds stop once we eat. Similarly, our intestines can make noises when they move food and gas along their length. These sounds are normal and occur as part of the digestive process, helping to move the food through the digestive tract and break it down for absorption. Eating regularly can help reduce these noises and keep our digestive system working smoothly.

COLOUR-CODED WEATHER WARNING

What are the different types of weather alerts by IMD (Indian Meteorological Department?

Colour- Coded Weather Warning

It is issued by the IMD whose objective is to alert people ahead of severe or hazardous weather which has the potential to cause damage, widespread disruption or danger to life.

Warnings are updated daily.

Green (All is well): No advisory is issued.

Yellow (Be Aware): Yellow indicates severely bad weather spanning across several days. It also suggests that the weather could change for the worse, causing disruption in day-to-day activities.

Orange/Amber (Be prepared): The orange alert is issued as a warning of extremely bad weather with the potential of disruption in commute with road and rail closures, and interruption of power supply.

Red (Take Action): When the extremely bad weather conditions are certainly going to disrupt travel and power and have significant risk to life, the red alert is issued.

These alerts are universal in nature and are also issued during floods, depending on the amount of water rising above land/in a river as a result of torrential rainfall.

For instance, when the water in a river is ‘above normal’ level, or between the ‘warning’ and ‘danger’ levels, a yellow alert is issued.

DO YOU KNOW

How was the first artificial sweetner invented?

The first artificial sweetner to be invented was saccharin. Russian chemist Constantin Fahlberg is credited with this invention, which was actually accidental. In the late 1870s, Fahlberg was working with another chemist, Ira Remsen. Together, they were studying substances derived from coal tar. 

One evening, Fahlberg returned returned home and sat down for dinner. As he bit into a roll, he found it sweet. He asked his wife about this, but she claimed that her rolls were perfectly normal. Fahlberg then tasted his fingers. They were sweet. 

He rushed back to his lab and began checking up all that he had done that day. He found that he had accidentally invented a substance that was as sweet as sugar, but had no fattening effects like sugar. He named this substance 'saccharin'. It caught on commercially and Fahlberg grew rich. 

DO YOU KNOW

What causes lightning and thunder?

Have you ever wondered why we have thunder and lightning during storms? Well, this is because when clouds move around in the sky, they bump into each other and create electricity. This electricity builds up until it suddenly bursts out in a big flash of lightning! The lightning is like a super-fast bolt of energy that lights up the sky. And the loud rumbling thunder you hear afterwards is because the lightning heats up the air so fast that it makes a booming noise. 

Thunderstorms always have lightning (since thunder is caused by lightning, and you can't have a thunderstorm without thunder), but you can have lightning without a thunderstorm. Lighting can also be seen in volcanic eruptions, extremely intense forest fires, surface nuclear detonations, and even in heavy snowstorms! It is possible that you might see lightning and not hear any thunder, because it was too far away. Sometimes this is called 'heat lightning' because it occurs most often in the summer. So, the next time you see lightning and hear thunder, remember that it's just nature putting on a spectacular show for us to enjoy!