Category Science

How is the age of a meteorite determined?

Meteorites are chunks of matter that fall from outer space. Their size ranges from small pebbles to huge rocks that weigh many tonnes.

Meteorites contain radioactive atoms of uranium. Some of these radioactive atoms gradually decompose to form the stable element, lead.

Scientists have estimated that it takes about 4.5 billion years for half the quantity of uranium in any sample to turn to lead. This time span is known as the half-life of a radioactive element. So the amount of lead present in the meteorite sample is measured using a mass spectrograph and then by calculating how much of the original uranium has decomposed, the age of the meteorite is worked out.

This method, called the radiometric dating technique, has been used to find the age of several meteorites. E.g., the over 60-ton Hoba meteorite found in Namibia, the largest ever, is estimated to be 200-400 million years old.

 

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What is praxinoscope?

It is an early animation device that predated the movie camera. It was invented in 1877 by Charles-Emile Reynaud of France. It was an improvement upon an earlier device called zoetrope.

The praxinoscope consists of a rotating drum whose inside rim is lined with a strip of pictures containing a succession of consecutive images. The strip may show a clown juggling, horse galloping, trapeze artist in action, etc.

At the centre is a small cylinder covered with mirrors, equal to the number of pictures in the rotating drum. When the drum is spun by hand, the pictures on the strip are reflected in the mirror. The observer sees a rapid succession of images, giving an illusion of a moving image.

Reynaud later called hid praxinoscope Theatre Optique (Optical Theatre) and used it as a part of his shows. He developed it further, projecting the image on a large screen for his audiences. It was very popular until 1900 when it was eclipsed by the cinematograph of the Lumiere Brothers.

 

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What is 4-D?

The term 4-D (sometimes 5-D) is used for movies that make use of physical effects inside the theatre, which occur in synchronization with the 3-D movie. These include seats which vibrate, tilt, sway, drop down and rotate, different kinds of smells to suit what’s happening on screen, for example, burning rubber in a car chase; rain, smoke, wind; strobe lights, water sprays and jets and even mechanical ticklers for the legs and arms!

A 4-D experience can be had only in special theatres which are built to produce the effects. There are movie theatres like these in many countries including India (Chennai, Mumbai, Delhi etc).

Ten films, including Avatar, Kung-Fu Panda and the third sequel to the Pirates of the Caribbean have additional 4-D effects.

 

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How to become an air quality specialist?

We often come across news articles describing the air quality in certain parts of the world as either ‘good’ or ‘bad’. The quality of air refers to the amount of pollutants present in the atmosphere. And it is the job of the air quality specialists to monitor air pollution and report it. Air quality specialists work for government and private agencies. They analyse the air we breathe to check if the air is safe and free of pollutants. Vigorous monitoring helps in altering people and initiating actions in case of extreme pollution. So if you want to help build sustainable, livable cities and contribute towards a low-carbon economy, then air quality assessment could be the right career option for you.

How it works

Air quality specialists test air samples from various environments and determine whether it meets the set standards. Monitoring air quality is also significant as policy makers can frame policies to curb air pollution and for the environment experts to understand the impact of policy changes. Real-time monitoring plays a key role in calculating air quality index (AQI) to issue health advisories as well as from action plans to meet standards.

Required skills

  • Analytical skills
  • Problem-solving skills
  • Good communication skills to simplify technical documents
  • Awareness of occupational safety and health issues
  • Interest in preserving the environment

Scope

In India, air quality specialists work with the Central Pollution Control Board, State pollution control boards, pollution control committees, and National Environmental Engineering Research Institute in cities. Air quality specialists are also needed by non-government agencies and action groups working to reduce air pollution.

What to study?

If you are interested in pursuing a career as an air quality specialist, a degree in environmental engineering – Bachelors of Technology (B.Tech) is a must. A Bachelors (B.Sc) and a Masters (M.Sc) in Environmental Science will also be helpful.

Where:

  • Indian Institute of Technology Kharagpur. B.Tech in Environmental Engineering.
  • Ch BP Government Engineering College, New Delhi: B.Tech in Environmental Engineering.
  • Banaras Hindu University: M.Sc in Environmental Science (Environmental Technology)
  • Garware Institute of Development University of Mumbai: M.Sc in Sustainable Development and Environment Management.
  • Savitribai Phule University, Pune: M.Sc in Environmental Sciences.
  • Jawaharlal Nehru University, Delhi: M.Sc in Environmental Sciences.

 

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Who is the architect of Indian nuclear programme?

The Bhabha of India’s nuclear plans

Whether it is used for defence or development, there’s no denying the importance of nuclear energy. Though India is not part of the Nuclear Suppliers Group, the country has made significant strides in nuclear science – it is now equipped with 22 nuclear reactors in seven power plants. And it is all thanks to the efforts of people like Dr. Homi J. Bhabha, who is known as the father of India’ s nuclear programme.

Early life

Bhabha was born in Mumbai on October 30, 1909. A close relative of Dorabji Tata, a key figure in the development of the Tata Group. Bhabha’s family persuaded him to pursue mechanical engineering and join the Tata Iron and Steel Company in Jamshedpur. But Bhabha discovered his true calling was physics.

He conveyed his change of heart in an insightful letter to his family, which reflects his passion for the subject. ‘The business or job of engineer is not the thing for me. It is totally foreign to my nature and radically opposed to my temperament and opinions. Physics is my line. I shall do great things here,” he wrote.

He studied in Cambridge, where he was internationally recognized for his work with cosmic rays. Bhabha was working in the famed Cavendish Laboratory where many discoveries of the time were taking place.

World War II

Bhabha returned to India for a short vacation, where World War II broke out. Instead of going back to England, he decided to stay on in India. He joined the Noble Laureate C.V. Raman’s laboratory at the Indian Institute of Science (IISc) Bangalore.

Bhabha strongly believed that India had to develop its nuclear capabilities so as to emerge as a power to reckon with. He said the country had to develop an atom bomb if it needed to defend itself. He convinced India’s Prime Minister Jawaharlal Nehru to start a nuclear programme and became the founding chairperson of the Atomic Energy Commission in 1948.

Powering development

Bhabha formulated India’s three-stage nuclear power programme in 1954, which is even followed today, to secure the country’s long-term energy independence. The programme was developed around India’s limited uranium and thorium reserves found in the coastal regions of South India.

Bhabha was appointed the President of the United Nations Conference on the Peaceful Uses of Atomic Energy in Geneva, Switzerland, in 1955. He served as the member of the Indian Cabinet’s Scientific Advisory Committee.

Promoting nuclear research

Besides strengthening India’s nuclear programme, Bhabha also helped promote research in fundamental sciences and mathematics. Along with JRD Tata, Bhabha established the Tata Institute of Fundamental Research (TIFR) on the campus of IISc. It was later shifted to Mumbai, and gained international recognition in the fields of cosmic ray physics, theoretical physics and mathematics. Bhabha built a new laboratory dedicated to technology development for the atomic energy programme. It was called Atomic Energy Establishment, Trombay, in 1954, and later renamed Bhabha Atomic Research Centre (BARC) after his demise.

Death and legacy

Both TIFR and BARC served as the cornerstones of India’s development of nuclear weapons, which Bhabha supervised as a director. Following rising tensions after the Sino-India war, Bhabha boasted of India’s nuclear capabilities in a famous speech on All India Radio in 1965. He said if he had the green signal, India could make a nuclear bomb in 18 months. Three months later, on January 24, 1996, he died in a plane crash when Air India Flight 101 flew into Mont Blanc in France. He was on his way to Vienna to attend a meeting of the Scientific Advisory Committee of the International Atomic Energy Agency. While conspiracy theories about Bhabha’s death still abound, India on this day lost one of its finest nuclear scientists at the prime of his career.

Brush strokes

Not just science, Bhabha was equally fond of music and art. His superb drawing skills won him many awards at the annual exhibitions of the Bombay Art Society. Even today, his paintings along with other priceless collections of art are on display at the TIFR and BARC campuses, making them unique among scientific institutions in the world.

 

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Who built a prototype renewable energy-gathering HARVEST device?

A step towards clean energy

You know the future is in good hands when children are raising their voices against issues and inventing things that are beneficial to society.

One of them many things invented by children that can prove to be helpful to society is HARVEST, a bio-inspired energy device that captures energy from sun, rain and wind, and converts it to power.

Maanasa, and the inspiration

Maanasa Mendu is a 16-year old high school student from Ohio, the U.S. She has been interested in science since the beginning of her schooling.

Participating actively in the science fair project in her school, her first project was testing Vitamin C content of different fruits. She was surprised when she discovered that strawberries had more vitamin C content than oranges.

During one of her vacations to her grandparents place in rural India. Maanasa encountered frequent power cuts. She realised that the power would be cut off every day at the same time in an attempt to distribute power to other places. This would leave people in the darkness.

Maanasa was affected by this and decided to use her knowledge in science to help out with such situations.

It’s HARVEST time!

Once she returned, Maanasa built a prototype renewable energy-gathering device called HARVEST. HARVEST mimics the shape of a tree (though much smaller) and uses piezoelectric materials to capture power from wind and rain. Piezoelectric materials capture mechanical energy and convert them into electrical energy.

Maanasa worked with piezoelectric materials for a long while. She even entered her Class VII and VIII science fairs with piezoelectric projects.

Maanasa’s HARVEST was inspired by the movement of leaves. So, she built a small structure with piezoelectric stems and Styrofoam leaves – which looks like a tree, and made an entry video for the 2016 Young Scientist Challenge when she was in Class VIII.

Mannasa’s entry was selected and she spent the next few months working on her prototype and learning about renewables, electrical engineering, prototyping and more.

After discussion with her mentor about the practical requirements of a renewable energy source, Mannasa integrated flexible solar cells into the device. This meant the device could now harvest energy from the sun as well.

HARVEST now had a plastic bottle as the main structure, with three wings that mimic the leaves on a tree, These wings were fitted with solar cells. And her entire device cost just US $ 5! She has even managed to charge a mobile phone and power a 15-watt LED bulb using the device.

Mannasa’s invention went on to win the 2016 Young Scientist Challenge and the title of American’s Top Young Scientist.

She is currently working to commercialize the device.

 

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