My Science School

We see them everywhere on the floor, up the ceiling, inside the sugar jar, outside the half-open pouch of a half-eaten snack... Ants are moving constantly, on different surfaces, and make it look so very easy. How do they do it? A biologist studying ants for three decades tells us how.

Ants have six feet, and each foot has five jointed segments. Each of these segments has spines and hairs, which provide the ants traction on rough surfaces such as barks. The last segment also has a pair of claws that help with a good grip on irregular surfaces. Together, both spines and claws act like our shoes – protect ants from hot and sharp objects. But the true magic of how ants conquer almost any surface lies between their claws.

Located between each pair of their claws is an inflatable sticky pad called arolium (plural arolia). When an ant climbs a wall or walks across a ceiling, gravity will pull it. But before that happens, its "leg muscles pump fluids into the pads at the end of its feet, causing them to inflate". This sticky fluid-called hemolymph- is similar to our blood and circulates throughout its body. A little bit of this liquid oozes out of the arolium when an ant places its leg on the surface, allowing it to stick to the surface. And when it removes its leg from the surface, the leg muscles contract and absorb the liquid back in the body. So, the liquid is used over and over again. Since ants are light-weight, these six pads are adequate enough to give them their gravity-defying grips on any surface "In fact, at home in their underground chambers, ants use their sticky pads to sleep on the ceiling By sleeping on the ceiling, ants avoid the rush hour traffic of other ants on the chamber floors.’’

Did you know?

When we walk, our left and right feet alternate, meaning one foot is on the ground and the other in the air to help us move forward. Ants do the same thing too- when they move, three of their legs are on the surface and three in the air at a time.

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Sunspots are regions on the sun that appear dark. They occur in regions where the magnetic field of sun is strong. The temperature of a sunspot is super hot-something around 6,500 degrees Fahrenheit

The Sun, the centre of our solar system and our closest star, is 4.5 billion years old. This fiery glowing orb of hydrogen and helium sustains life as we know it

Sunspots

Sunspots are regions on the sun appear dark. These parts appear darker as they are cooler when compared to other parts of the sun. They occur in regions where the sun's magnetic field is highly concentrated or strong.

The centre of the sunspot is dark and this is called the umbra while the outer and lighter ring is called the penumbra. Spots vary in sizes. They could be larger than the Earth, or so tiny that it will be difficult to pick them up in telescopic observation. The sunspots could stay on for months. Most of the sunspots can be seen in pairs or groups but single spots also do occur. When they occur in pairs, they have opposite magnetic polarity.

Why are sunspots cooler

Sunspots form in areas on the sun where the magnetic field is very strong and powerful. These magnetic fields will prevent the heat within the Sun from reaching its surface. Even when we say that the sunspots are cooler, this is just in comparison to the other regions of the Sun. The temperature of a sunspot is super hot something around 6.500 degrees Fahrenheit.

Why do sunspots matter

 In most cases, sunspots precede the occurrence of a solar flare. Solar flares are sudden bursts or explosions of energy from the sun's surface. This occurs when the magnetic field lines near the sunspots reorganise or cross. These solar flares will release huge amounts of radiation into space. The more intense the solar flare, the more intense will be its radiation. This can affect radio communication on Earth. Studying and monitoring the sunspots are required to understand the reason behind the occurrence of solar flares.

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India ranked 132 out of 191 countries in the 2021 human development index, according to a report released by the United Nations Development Programme (UNDP). But what is the human development index? Come, let's find out.

The Human Development Index (HDI) is a measure of countries' life expectancies, education levels, and standards of living. In other words, HDI is a statistical tool used by the UN to quantify a country's overall achievement in health, education, and economic status. The index, introduced by the UN in 1990, is used to track changes over time and compare the levels of development of different countries. It is said that human development across the world has stalled for the first time in 32 years.

Reasons for the decline

The COVID-19 pandemic, along with other crises such as the Ukraine-Russia war, climate change, higher cost of living, and spiralling energy prices, has pushed the global development measurement back to its 2016 level, according to the UN report titled "Uncertain Times, Unsettled Lives: Shaping our Future in a Transforming World". A large contributor to the HDI's recent decline is a global drop in life expectancy, down from 72.8 years in 2019 to 71.4 years in 2021. Human development is said to have declined for two years in a row - 2020 and 2021.

How is development measured?

The HDI measures the social and economic development of a country based on three key aspects- a long and healthy life, access to education, and a decent standard of living. It is calculated using four indicators - life expectancy at birth, mean years of schooling (average number of completed years of education of a country's population), expected years of schooling, and the Gross National Income per capita (annual national income per person in a country). The higher the HDI, the better a country's overall development is. So a high HDI means the country in question provides a high standard of living, with decent healthcare, education, and opportunities for livelihood.

India's HDI value

India's HDI value of 0.633 places the country in the medium human development category. This is lower than the country's value of 0.645 in the 2020 report. In 2020, India ranked 131 among 189 countries in human development.

In the latest HDI ranking, Switzerland finished first with a HDI value of 0.962. Norway came second with 0.961, and Iceland third with 0.959.

The report recommends implementing policies that focus on 3 Is - investment (from renewable energy to preparedness for pandemics), insurance (to prepare our societies for the ups and downs of an uncertain world), and innovation (technological, economic, cultural to build capacities to respond to any challenges that may arise) - to push development.

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The impact of flying on climate change has been well established. On average, the aviation industry generates about 1 billion tons of CO2 worldwide every year. This number is comparable to that of Japan, which is the world's third largest economy.

Add to this the fact that global emissions from flights have been increasing at the rate of 2.5% every year. In fact, over the next 30 years, the aviation industry will likely produce more CO2 than that of its whole history!

Radical solutions required

Even though fossil fuels are increasingly being replaced by renewable energy sources in power generation and electric vehicles continue to grow into a bigger market, there hasn't been enough done to address pollution from aircraft. In such a climate, the need is for bold, radical solutions. Researchers from the University of California San Diego School of Global Policy and Strategy have called for the same through a new commentary article that appeared in Nature in September.

The authors suggest that the two most commonly proposed solutions-carbon offsetting and cleaner fuels - are rather inadequate. While offsetting falls flat owing to poor accountability, cleaner fuels can't yet be produced sustainably in large volume and low costs to replace all jet fuel. Additionally, these two solutions do not address the dimate impact of contrails-clouds produced by aircraft engine edhaust - that can trap heat radiating from the Earth's surface.

Three steps

To address a warming planet, the authors suggest three steps for the industry as a whole. Firstly, they recommend the industry and various governments to work together to be more aware of the risks involved and the role that aviation plays in the dimate crisis.

Next up, they wish for collaborations between the most motivated governments and firms to take risks on new technologies, which could then inspire others to follow their lead. The authors only provide examples such as a partnership between the Norwegian government and businesses to create electric airplanes, but also lay out strategies of how collaborations could be used to ignite other advances.

Finally, they stress the importance of research, not just to better understand contrails and chemical interactions in the atmosphere, but also to provide solutions. They envision these solutions to not just be technological, but also economic and political, thereby providing for a greener future.

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The Atomichron, unveiled on October 3, 1956, was the world's first commercial atomic clock. At a time when timekeeping is more accurate than ever before.  

In his work of fiction The Time Keeper, American author Mitch Albom has one of his characters say that "man will count all his days, and then smaller segments of the day, and then smaller still- until the counting consumes him, and the wonder of the world he has been given is lost. While the last part of the statement is rather too deep, and well beyond the scope of this column, there might be some truth with respect to the counting consuming us.

Comes down to counting When we started, we looked up at the sun and the moon to get a sense of time. We picked up stones, collected water, and were able to tell time even better. And now, we have come to a stage where the best of our clocks are so precise that it would take around 30 billion years for it to lose even one second.

And yet, at the heart of it, the fundamental process remains the same as we count a periodic phenomenon. In a grandfather clock, the pendulum swings back and forth. In a wristwatch, an electric current ensures that a tuning fork-shaped piece of quartz oscillates. And when it comes to atomic clocks, we use certain resonance frequencies of atoms and count the periodic swings of electrons as they jump between energy levels.

What are atomic clocks? The best of our clocks, by the way, are atomic clocks. As we learned more of the atom's secrets, we were able to build practical applications, including these clocks.

We now know that an atom is made up of a nucleus - consisting of protons and neutrons- that is surrounded by electrons. While the number of electrons in an element can vary, they occupy discrete energy levels, or orbits.

Electrons can jump to higher orbits around the nucleus on receiving a jolt of energy. As an individual element responds only to a very specific frequency to make this jump, this frequency can be measured by scientists to measure time very accurately.

Been around since 1950s

By the mid 1950s, atomic clocks with caesium atoms that were accurate enough to be used as time standards had been built.

The Massachusetts Institute of Technology Research of Electronics developed the first commercial atomic clocks around the same time, and these were manufactured by the National Company, Inc. (NATCO) of Malden, Massachusetts.

Initially, the atomic beam clocks that NATCO were building were called just that: ABC. By 1955, the prototypes bore the working name National Atomic Frequency Standard (NAFS). As this acronym was clearly not pleasing to the ear, there was a need for a better name to market the first practical commercial atomic clock.

Quantum electronics equipment

They came up with the name Atomichron, which NATCO then made its generic trademark for all their atomic clocks. In a well publicised event at the Overseas Press Club in New York, the Atomichron was unveiled to the world on October 3, 1956.

The first commercial atomic clock was indeed the first piece of quantum electronics equipment made available to the public. In the years that followed, 50 Atomichrons were made and sold to military agencies, government agencies, and universities.

Defining a second

By 1967, the official definition of a second by the International System of Units (SI) was based on caesium. This meant that the internationally accepted unit of time was now defined in terms of movements inside atoms of caesium.

Atomic clocks, however, aren't going to come home soon. At about the size of a wardrobe, it consists of interwoven cables, wires, and steel structures that are connected to a vacuum chamber that holds the atoms.

These clocks, however, are already in use everywhere around us. Be it satellite navigation, online communication, or even timed races in the Olympics, atomic clocks are in action. The best of our atomic clocks, as you might guessed, are employed in research and experiments to further our understanding of the universe around us.

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