DISPLAY OF LIGHT WITH SOUND

Firecrackers and Fireworks

Explosive firecrackers and brilliant fireworks are the hallmarks of the joyous Diwali festival.

Be it the sparkling phooljhari, spinning chakra, fountainlike anaar, flying rocket or the Laxmi bomb — the dazzling fireworks captivate one and all during the days of the festival of lights.

Bursting firecrackers is an ancient practice that has its origins in China. It is said that a Chinese monk named Li Tian stuffed a green bamboo with gunpowder and threw it into a fire. The bamboo exploded suddenly and thus was born the firecracker. 

Firecrackers go off with a bang where as fireworks are a visual delight, setting the night skies ablaze with their splendour. Also called pyrotechnics, fireworks shows are not just about noise but also about light, smoke and colour.

The Recipe

A firecracker consists of gunpowder or flash powder wrapped very tightly in a paper tube, with a fuse. Gunpowder is a combustible mixture of potassium nitrate, charcoal and sulphur. These ingredients react with each other chemically to produce nitrogen and carbon dioxide gases when heat is applied by lighting the fuse. As the heated gases expand, the paper wrapping is ripped apart, producing the explosive sound. Flash powder burns quicker than gun powder and produces a loud bang with a flash of light.

Various types of fireworks produce different kinds of visual and sound effects depending on the chemicals stuffed in them. The most common component is aluminium, which emits silvery white sparks. Potassium imparts a violet shade while barium is used to create green colour. The pyrotechnic composition thus determines whether the firework emits a lot of smoke, glitters in a palm tree effect, whistles or crackles upon explosion.

Industrial Centre

Sivakasi is the fireworks capital of India with more than 600 manufacturers generating an annual turnover of Rs 7,000 crores. Dry climate and scanty rainfall as well as easy availability of raw materials make Sivakasi ideal for the fireworks industry. An impressed Jawaharlal Nehru nicknamed the industrial town ‘Kutty Japan’ (Mini Japan). However, Sivakasi was condemned for its use of child labour and today, steps have been taken to eradicate the practice.

The Darker Side

While fireworks continue to dazzle, they also create air, water and noise pollution apart from causing serious injuries. According to a 2016 study by the Pune-based Chest Research Foundation, burning a single cracker emits pollutants equal to the burning of 500 cigarettes at a time. The smoke contains traces of heavy metals and other toxic chemicals such as sulphur dioxide, magnesium and nitrates, which lead to health problems, especially respiratory ailments. Even the noise from the crackers— with decibel levels in excess of 90 — is harmful. Last year, the Supreme Court banned the sale of firecrackers in Delhi NCR. The smoke combined with the wintry mist leads to a spike in the levels of fine particulate matter with a diameter of 2.5 micrometres or less (PM 2.5) in the air. These particles, which are 30 times finer than human hair, accumulate in the internal organs and bloodstream, causing sickness.

People, especially children, burst firecrackers from very close quarters, about a foot away. So they directly inhale the smoke pollutants in large quantities. Of all the firecrackers, the snake tablet burns for less than 10 seconds but produces the highest levels of PM 2.5, followed by the ladi, phooljhari, chakri and anar.

Fast Facts

◆ At the stroke of midnight on 1 January 2016, wide eyed spectators witnessed the world’s largest display of 8,10,904 fireworks in the Philippine Arena, an indoor stadium in the Philippines. The show lastedfor an hour — a Guinness World Record!

◆ In May 2010, as many as 1,25,801 rockets were launched in 30 seconds in a record-making event in Cebu, Philippines.

◆ China is the largest manufacturer and exporter of fireworks in the world.

THE MIRACLE GRASS

Vetiver 

Originally derived from Tamil, the word ‘vetiver’ means a ‘root that is dug up’. Its botanical name is Chrysopogon zizanioides. It is called khus in Hindi.

Ancient Ayurvedic texts refer to the use of ushira (Sanskrit word for khus roots) in wells and reservoirs to get rid of the foul smell orbitterness in water. It is found all over India, particularly along river banks and marshylands. 

Vetiver is a perennial grass that is now cultivated in over 70 countries with both tropical and temperate climates. Scientists have recognized its vital role in reducing soil erosion, recharging ground water, and absorbing toxic pollutants in water. The grass has also found favour with the pharmaceutical industry because of its scented essential oil that is extracted from the roots. No wonder, the people of Mali in Africa call vetiver a ‘plant that never dies’.

Vetiver is used in numerous products—baskets, mats, brooms, coir netting in air coolers, etc. But the greatest use is in the rural areas where vetiver strips are planted to prevent soil erosion. In the village of Chellagurki in the Bellary district of Karnataka, some 5,000 strips have been ordered to stabilize the watershed area.

In China, vetiver has been grown for soil erosion although it was initially planted in the early 1950s to extract oil from its roots. The man credited for its wide distribution is Richard Grimshaw, a former official at the World Bank who took a thousand vetiver strips from Bangalore to China in 1988.

THE BOARD GAME

Mastermind 

The board game Mastermind is designed to be played by two persons above the age of eight. One of the players creates a code and the other tries to decipher it with the help of the clues. 

The game consists of a decoding board, code pegs and key pegs. The board has twelve rows, each with four large and eight small holes. At the two ends of the board are four large holes covered by a shutter. This is where the player creates a secret code using any of the six coloured pegs.

The code-breaker has to guess the colours of the code pegs and their exact positions. He gets twelve chances to do so. After each attempt, the code-maker provides a clue and the code-breaker responds by filling in a row of code pegs on the board. The code-maker indicates which part of the guess is right or wrong by placing flat key pegs on the board. 

The game continues until the code-breaker cracks the code or completes twelve guesses.

FOR SECURITY PURPOSE

If AI is so clever, why can't it solve a CAPTCHA?

CAPTCHAs (Completely Automated Public Turing test to tell Computers and Humans Apart) are special puzzles on the internet made to tell the difference between humans and computers. They’re meant to be tricky for machines but easy for people to solve.

Here’s why AI, which is like a very clever computer, sometimes has trouble with CAPTCHAs:

HARD TO SEE: CAPTCHAs often show wobbly letters, numbers or pictures that are hard to read. While AI is good at recognising normal images and text, CAPTCHAs are made to be confusing so that computers can’t easily figure them out.

ALWAYS CHANGING: As computers get better at solving certain CAPTCHAs, new and harder ones are created to stay ahead. This means that CAPTCHAs are always being made trickier to keep computers from solving them.

HOW AI THINKS: AI doesn’t ‘see’ things like humans do. It looks for patterns in what it’s  been taught. If a CAPTCHA breaks these patterns by being extra confusing, the AI might not be able to solve it.

KEEPING THINGS SAFE: The main job of CAPTCHAs is to stop robots (automated programs) from doing things like making fake accounts or sending lots of spam. Even though AI can sometimes solve CAPTCHAs, letting it do that would ruin the whole point of using them for security.

So, even though AI is very clever, CAPTCHAs are designed to be tricky on purpose, so computers can’t easily get past them. That said, AI is getting better and better at this. In fact, a 2023 study showed that most AI can solve CAPTCHA with a 96% accuracy – while humans’ accuracy ranges from 50-86%!

ANCIENT WORLD

What are hieroglyphs?

This strange-sounding word actually describes a form of picture writing used by the ancient Egyptians. 

The Egyptians used about 1000 pictures or hieroglyphs to express their thoughts. Each hieroglyph stood for an object, sound or idea. The hieroglyphs were written on paper called papyrus, made of reeds. Gradually, people stopped using hieroglyphs and in time, everyone forgot what the pictures meant. Then, in 1799, a stone called the Rosetta Stone was found, which had writing in three languages, including the hieroglyphic language.

A Frenchman named Jean Francois Champollion was able to translate the hieroglyphs and now scholars of the ancient Egyptian civilisation can read hieroglyphs. If you want, you can learn it too when you grow up!

DO YOU KNOW

Reason for side holes in sneakers 

The side holes, also known as "ventilation holes" or "perforations", in sneakers serve several important purposes. Firstly, they enhance breathability by allowing air to circulate inside the shoe, which helps keep the feet cool and comfortable, especially during physical activities. The whole also aid in moisture management, allowing sweat and moisture to escape from the shoe, reducing the chances of discomfort and odours.

Secondly, the side holes contribute to the overall design and aesthetics of the sneakers, adding a distinctive style element. Some sneaker designs utilise the side holes as part of their branding or visual appeal.

Overall, the side holes in sneakers play a significant role in providing better ventilation, comfort and performance, making them more suitable for active and everyday wear.

STORY OF MATCH BOX

Rediscovering fire with a little stick

From striking stones against each other to lighting a matchstick, humans have come a long way when it comes to igniting fire. The first matchstick was invented accidentally by John Walker, an English chemist. Walker was stunned when a chemical coating stick burst into flames after contact with his stone fireplace. After this, he created a first prototype of the modern matchstick. Initially named ‘friction lights’, it became a trend in the market. However, Walker did not patent his invention. Samuel Jones launched matchsticks and called them ‘Lucifers’. They burst into unpredictable flames, emitting a peculiar smell. The tips of these matches contained a coating of antimony sulphide, potassium chlorate, starch and gum. These sticks could be ignited when stroked between folded sandpaper. The credit for creating noiseless matchsticks goes to Janos Irinyi, a student, in 1835. He replaced potassium chlorate with lead dioxide. This resulted in the sticks burning evenly throughout. Eventually, the safety matches we see today were invented by Swedish inventor and professor Gustaf Erik Pasch in 1844. After a decade, John Edvard Lundstrom improvised on the design. 

Ever wondered how a matchstick lights up with a single spark? The head of the match consists of antimony trisulfide, which acts as the fuel. Potassium chlorate aids in the fuel burning, leading to ignition of the matchstick. Whereas ammonium phosphate plays the other role, preventing the matchstick from emitting too much smoke after being extinguished. When you light a match, the flame travels downwards. This is due to the wax present on the matchstick. Glue holds all this together. The dye makes the matchstick look more presentable! Powdered glass is present on the striking surface, for friction, whereas red phosphorus ignites the flame. When you strike the match against the powdered glass, it creates friction, which leads to heat, and this converts red phosphorus to white phosphorus. White phosphorus is extremely volatile, and reacts with oxygen in the air. This results in the matchstick igniting. The flame that you see in the matchstick is due to heat which ignites the potassium chlorate. Potassium chlorate is an oxidiser, aiding in burning of the fuel by supplying more oxygen. This oxygen in turn mixes with antimony trisulfide, ensuring that the flame lasts longer. Paraffin wax is coated along the matchstick, ensuring that the flame travels all down the match, across the wooden stick. After the matchstick is extinguished, a familiar burnt scent is released. This occurs as the antimony oxidises and sulphur oxides form. The smoke that emanates is from tiny unburnt particles, from the incomplete combustion process. Usually, these particles are very minute, but when grouped together, they form smoke. A little amount of water vapour is also present. 

Matchboxes were perfected over time by Lundstrom and his younger brother Carl. Boxes were created as per the size and use of the matchsticks. Until 1830, the matchsticks were known as Lucifer matches. However, cigarette lighters were invented in 1816, much before matches were invented. Today, around the world, about half a trillion matches are used each year.