My Science School

Asteroids, also known as minor planets, are small, rocky bodies that have been left over from the formation of planets about 4.5 billion years ago. Billions of such rocks exist in the solar system, with the majority of them concentrated in a doughnut-shaped main belt of asteroids between the planets Mars and Jupiter.

It has been in our interest to study these minor planets. As remnants from the planet forming process, they can not only be viewed as building blocks of planets, but could also possibly hold clues explaining the evolution of Earth.

Simultaneous discovery

The Near Earth Asteroid Rendezvous (NEAR), later renamed NEAR Shoemaker, was a low-cost mission and the first to be flown under NASA's Discovery programme. Its target was the minor planet 433 Eros, which is approximately 355 million km from Earth, and it intended to gather information about its physical properties and composition, among others.

Eros was discovered by German astronomer Carl Gustav Witt on August 13, 1898, and by French astronomer Auguste Charlois independently on the same day. Breaking with the tradition of the time, it was given a male name Eros - the son of Mercury and Venus. Within weeks from its discovery, it was computed that Eros orbit brought it inside the orbit of Mars, making it the first near Earth asteroid to be discovered.

Mathilde flyby

Launched on February 17, 1996, NEAR was the first spacecraft to rely on solar cells for power for its operations beyond Mars orbit. Even though its primary objective was studying Eros, NEAR performed a 25-minute flyby of the asteroid 253 Mathilde on June 27, 1997.

NEAR's closest approach to Mathilde brought it within 1,200 km of the minor planet. From this distance, it was able to photograph 60% of the asteroid and gather data that indicated that the asteroid is covered with craters and less dense than previously believed.

Using a gravity assist during an Earth flyby encounter, NEAR headed next towards Eros. An aborted engine, however, meant that the spacecraft had to be stabilised and the initial planned trajectory to Eros had to be sidelined.

The backup trajectory that was then used put NEAR on a far longer path towards Eros. This meant that rather than entering orbit around Eros in January 1999, NEAR had to be content for the time being with a flyby of Eros on December 23, 1998. It turned out to be useful though as NEAR was able to observe 60% of the minor planet and discover that the asteroid was smaller than what was expected.

A love affair

Orbital insertion, however, wasn't yet out of the question and several efforts, including more course corrections, were under way to make another attempt in the following years. On February 14, 2000 - Valentine's Day-NEAR finally entered into orbit around Eros, an asteroid named after the god of love in Greek mythology. NEAR thus became the first human-made object to orbit any minor planet.

A month after entering into orbit, on March 14, 2000, NEAR was renamed NEAR Shoemaker by NASA in honour of planetary scientist and geologist Eugene Shoemaker. Shoemaker, who had died in an accident in 1997, was a pioneer in studying asteroid impacts.

Orbiter turns lander

In the months that followed. NEAR was able to orbit Eros many times and its operational orbit kept changing, allowing it to get closer to the asteroid than what was previously thought possible. Even though it was built as an orbiter, it went on to survive a landing on February 12. 2001, making it the first spacecraft to land on an asteroid

NEAR kept sending invaluable data until its last contact on February 28, 2001, when it succumbed to the extreme cold conditions on the surface of Eros. A further attempt by NASA to contact NEAR in December 2002 failed.

The photographs and information returned by NEAR Shoemaker not only helped map more than 70% of the minor planet's surface and provide data about its interior, but also showed that Eros had no magnetic field. Having relayed about 10 times more data than initially planned, including 1,60,000 images, NEAR's mission proved to be a tremendous success.

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When you swipe across the apps on a smartphone, or stare at the computer screen while attending your classes during the ongoing pandemic, do you ever stop to marvel at their wonders? If we were to look back at the different generations of computing, we would encounter a number of devices. While all of these more or less did the same thing at different scales, they were surely bulkier as we move back in time. We wouldn’t be able to go any earlier than the Baby, however, for it was the world’s first stored-program electronic computer.

Baby or Manchester Baby was the nickname of the Small-Scale Experimental Machine (SSEM) that was built in Manchester, England in 1948. Englishmen Frederic Calland Williams, Tom Kilburn, and Geoff Tootill were the developers of Baby, a machine of critical importance in the evolution of computers.

ENIAC lacked memory

The Electronic Numerical Integrator and Computer, or ENIAC, was one of the earliest general-purpose computers that was introduced in 1946. While it was programmable, electronic and could solve a large class of problems through reprogramming, what it lacked was a program memory.

By this time, however, the recipe for computers that will soon change the world were almost in place. Hungarian-American John von Neumann articulated his ideas about a computer and described its architecture, consisting of a processing unit, memory and external input / output units. The von Neumann Architecture was at the heart of SSEM and continues to have its say in the internal workings of modern computers.

Radar to memory systems

Williams and Kilburn were top-class engineers with excellent working knowledge of the technology of the time. After having made exceptional contributions to the electronics of radar during World War II, the two men sought to switch to new fields after the war when the urgency of radar development reduced.

Aware that solving the problem of storage or memory systems would lead to a boom in computers worldwide, Williams turned his attention to the problem, hoping to apply his knowledge of cathode ray tubes to the storage of data. He was able to successfully demonstrate the operation of a single bit memory in October 1946.

In December that same year, Williams moved to the University of Manchester to take up a chair in Electro-Technics, now referred to as electrical engineering. Kilburn joined him soon enough and they worked together on their memory project. Joined later by Tootill, the trio successfully built a memory system by the end of 1947 that could operate and hold data.

Newman, Turin pitch in

The ultimate test, however, was building a computer around this memory system and testing its capability. While Williams and Kilburn knew all about electronics, they had to turn for support with respect to computers. Thankfully, they had the best in the business as their colleagues in the university, and they sought the help of mathematicians Max Newman and Alan Turing. Based on their advice, Williams designed the Baby, and it was built mainly by Kilburn and Tootill.

Almost the entire first half of 1948 was spent building the Baby. And then, on June 21, 1948, a program stored in an electronic memory was executed successfully for the first time anywhere in the world by Baby. A world of change was about to unfold.

Documentation of the program, which was written by Kilburn, has survived, including Tootill’s lab notebook. The actual code that Baby ran has been found and the popular consensus is that the first program was designed to find the highest proper factor of any given number.

While individual computers previously had been built to cater to specific problems, the Baby showed that one computer could do different jobs and solve a variety of problems. While this is something we all take for granted now, the idea was revolutionary in the 1940s, and it is this universality that makes Baby’s success a cornerstone in the evolution of computing.

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It is an established fact that human beings observe what and where something is happening around them using their sense of hearing. Humans, however, have a limited range of hearing and can perceive only certain sound frequencies - generally stated to lie between 20 Hz and 20,000 Hz.

A new audio technique, developed by researchers at Aalto University, Finland, will now allow people to hear ultrasonic sources that generate sounds of frequencies over 20,000 Hz. The results, which were published in Scientific Reports early in June, also state that the technique would also allow for perception of the direction from which the sound is coming.

Listening to bats

Bats in their natural habitats were employed as the source of ultrasonic sound in this study.

Using their technique, the researchers were able to hear the direction of arrival of bat sounds, effectively allowing them to track the bats in flight as well as hear them.

While previous devices have allowed humans to listen to bats, the fact that this allows us to locate them as well is novel. They achieved this by recording the sound using an array of microphones that were mounted uniformly on a small sphere, performing a sound-field analysis and obtaining the most prominent direction from which the sound originates. Additionally, a parameter also indicates if the sound comes from a single source.

The signal thus produced is then pitch-shifted to audible frequencies and a sound is played in headphones immediately, allowing the listener to perceive the sound and the source based on the direction from which it was analysed to arrive. While the pitch-shifting was performed in a computer during the research, scientists believe that this could be achieved using electronics mounted on headphones as well.

Detect pipe leaks

Apart from the general appeal that it has for humans in the fact that it allows us to hear sounds that we normally can't, researchers also suggest practical applications. Minor pipe leaks and sometimes even damaged electrical equipment produce ultrasonic sounds that we can't hear with our ears. Their device would enable quickly detecting the location of such faulty equipment, saving valuable time.

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Temporary phenomena that occur on the sun, sunspots appear as spots that are darker than the surrounding areas. These seem dark to us only because of the difference in temperatures as these regions have reduced surface temperature as a result of intense magnetism.

There was a bitter dispute between Italian astronomer Galileo Galilei and German priest Christoph Scheiner in the 17th Century as to who deserved the credit for discovering sunspots. With hindsight, it is easy for us to tell now that the whole exercise was rather pointless due to two main reasons.

Dispute for what?

For one, sunspots had been observed for centuries before these two men came into the picture. There are surviving Chinese records that go back over 2,000 years that indicate possible sightings and also many mentions by Chinese astronomers. There were numerous other observations of sunspots through the centuries, only that the observers interpreted it mistakenly as the transit of a planet.

Secondly, historians now generally agree that Englishman Thomas Harriot was the first to observe sunspots using telescopes when he did it late in 1610. And even if we are looking at someone who published their findings, the credit for that would go to Dutch-German astronomer Johannes Fabricius.

Born Johann Goldsmid and better known by his Latinised name Johannes Fabricius, Johannes was the eldest son of Lutheran pastor and astronomer David Fabricius. While most of his early education in maths and science took place under his father’s watchful eyes, he was then supported by a wealthy patron.

World of telescopes

This meant that as a young man, Fabricius was able to finally pursue a more formal education. This took him first to the University of Helmstedt and University of Wittenberg in Germany and then to the University of Leiden in the Netherlands.

It was during his time at Leiden that Fabricius first encountered telescopes, which were an exciting new invention that was beginning to appear in the Netherlands. When he left for home, he carried with him several of these new telescopes to show his father. As David himself was an astronomer and had also worked with Europe’s celebrity astronomers such as Danish Tycho Brahe and German Johannes Kepler, Johannes was sure that his father would appreciate these new instruments.

Observe sunspots

Living then in Osteel, a town in the northwest part of Germany, father and son took to using the telescope to observe. On March 9, 1611, they rose at dawn and trained their telescope to view the sun and were surprised to see black spots on it. Direct observation, however, led to severe pain to the eyes, even if done before sunrise and after sunset.

This is best summarised in Fabricius’ own words (excerpt from a translation): “For indeed it was to be feared than an indiscreet examination of a lower sun would cause great injury to the eyes, for even the weaker rays of the setting or rising sun often inflame the eye with a strange redness, which may last for two days, not without affecting the appearance of objects.”

Given this situation, the duo switched to a camera obscura method of allowing the sun’s rays to enter a dark room through a pinhole opening and watching the resulting image on a sheet of paper. This allowed them to track and review the sunspot movement over subsequent sightings, enough to notice that the sunspot moved across the face of the sun, disappearing off one edge and reappearing at the other edge around two weeks later.

Publishes treatise

These observations were evidence of the sun’s rotation about its own axis. Fabricius ruled out planetary transits or clouds being responsible for these spots and rightly concluded that these spots were on the sun’s surface. He published their findings in a 22-page pamphlet titled “De Maculis in Sole observatis et Apparente earum cum Sole Conversione Narratio” (Narration on Spots Observed on the Sun and their Apparent Rotation with the Sun), which had its dedication dated June 13, 1611. This was the first published treatise that spoke about sunspots.

Isolated from the larger world and its leading astronomers and lacking influential backing, Fabricius’ work languished in obscurity for decades before it was identified for what it was. Unaware of what Fabricius had achieved, Galileo and Scheiner, who had their works on sunspots published in the following years, were embroiled in a bitter battle to stake a claim to the discovery.

All those sunspot sightings, which proved that the sun moved and changed, and wasn’t “perfect” as stated in religious dogma, along with other mounting evidence, meant that the fact that the sun is at the centre of the solar system finally came to be accepted as the truth within a generation. Fabricius wasn’t around to see that unfold, however, as he died at the rather young age of 29 in 1616. Sunspots, meanwhile, continue to fascinate humankind till this day.

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Do you know that the first images that correspond to you are taken these days even before you are born? Obstetricians (doctors who practice obstetrics, the field of study that concentrates on pregnancy, childbirth and the post-partum period) use ultrasound to produce pictures of a baby (embryo or foetus) within a pregnant woman.

An imaging test, ultrasound scans use sound waves to create a picture of organs, tissues and other structures inside the body without using radiation, unlike x-rays. The physician who developed ultrasound diagnostics, thereby enabling doctors to detect potentially fatal issues and prevent health problems, was Englishman Ian Donald.

Bridging both worlds

Born in 1910 in Cornwall, England, Ian Donald was the eldest of four children born to Helen Wilson and John Donald. Helen was a concert pianist and John was a doctor and Ian grew up to become someone who tread both the worlds of art and medicine with panache.

After beginning his formal schooling in Scotland, Donald moved with the rest of his family to South Africa in 1925. He studied at the Diocesan College in Cape Town and then the University of Cape Town, majoring in arts and music, with a fine understanding of literature and a number of languages.

Having lost his parents while in South Africa, Donald moved to London with his siblings in 1930 and entered St. Thomas’ Hospital Medical School in London in the same year. After receiving his medical degree in 1937, Donald became a general practice physician in the Obstetrics and Gynaecology Department at St. Thomas’ Hospital.

Wartime learnings

During World War II, Donald was drafted into the Royal Air Force. It was in this period that Donald was drawn towards sonar (sound-based) and radar (based on high-frequency electromagnetic waves) techniques that were used during warfare to navigate, communicate and detect objects underwater.

Returning to St. Thomas’ after the war, Donald found himself in a position where he could spend time on research. Working alongside Maureen Young, who specialised in foetal and neonatal physiology, Donald developed an improved design for a negative pressure respirator to help premature babies with breathing difficulties. As opposed to existing neonatal respirators that had a set rhythm and hence made breathing more difficult for the babies at times, Donald’s device conformed to the infant’s breathing pattern.

Works on respirators

In 1952, Donald moved to Hammersmith Hospital in London and continued his research, developing a positive-pressure respirator. This device, which could be applied to the patient in under a minute, delivered an oxygen mixture to the infant’s face. While the negative-pressure respirator was ideal for long-term treatment, the positive-pressure respirator was more suited for crisis scenarios.

In 1954, Donald met English-born American physician John Wild, who had had success in using pulse-echo ultrasounds to visualise abnormal tissue in the human breast. Based on his wartime sonar, radar experiences and seeing the potential of using ultrasound to obstetrics, Donald sought Wild’s opinion and he suggested using ultrasonic industrial flaw detectors.

In that same year, Donald was appointed to the Regius Chair (a chair endowed by the British Crown) of Midwifery at the Glasgow Maternity Hospital in Scotland. As fate would have it, one of Donald’s patients introduced him to her husband, the director of Babcock and Wilcox, an industrial fabrication company, in 1955.

Three-man team

As a major user of industrial ultrasound, including flaw detectors for checking cracks in welds and steel plates, Babcock and Wilcox was the perfect setting that Donald could have imagined. When invited on a tour to their factory, Donald was all eyes during the demonstration of the ultrasonic flaw detector. When the technician tested the equipment by bouncing off an ultrasonic beam off his thumb, Donald was certain that these could be applied to biological material.

By 1956, Donald started working with Thomas Brown, an engineer at Kelvin and Hughes Ltd. in Glasgow who had a sound understanding of industrial ultrasound technology. Brown had already been dabbling with medical imaging along with Scottish physician John MacVicar and Donald too had been working with MacVicar.

Based on the medical knowledge of Donald and MacVicar and the engineering acumen of Brown, the trio mastered the use of ultrasound as a diagnostic technique and also came up with an ultrasound machine. In 1957, they used their technology to show that a woman, previously diagnosed with an inoperable gastric cancer, actually had an ovarian cyst. Their diagnosis was confirmed by surgical intervention and the cyst was successfully removed.

First ultrasound images

On June 7, 1958, Donald, MacVivar and Brown published their findings in The Lancet in a paper titled “Investigation of abdominal masses by pulsed ultrasound”. The seminal paper contained the first ultrasound images of the foetus and brought global attention to the three men.

Even though the idea was initially greeted with scepticism, it gained widespread acceptance from the medical community and the public with time. Donald, MacVivar and Brown constantly improved their device to build a scanner that could be handled efficiently.

In the years that followed, Donald’s work with ultrasound ensured that the foetus was no longer invisible to doctors and monitoring foetal development became much easier. By the time Donald died in 1987 due to his many heart problems, he had seen his idea grow to become the standard clinical practice world-over.

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Gertrude B. Elion was an American pharmacologist, who won the 1988 Nobel Prize in Medicine, along with George H. Hitchings and Sir James W. Black, for pioneering work in drug development.

Gertrude B. Elion was born in New York City in 1918. She graduated from Hunter College in New York City with the degree in biochemistry in 1937. Unable to obtain graduate research position, she took up jobs as a secretary, a chemistry teacher, and an assistant in a lab. During this time, she pursued graduate studies at night school in the New York University. As she could not devote herself to full-time studies, Elion never received a PhD.

In 1944, she started to work as an assistant (and later became a colleague) to George H. Hitchings at the Burroughs-Wellcome pharmaceutical company (now GlaxoSmithKline). Elion and Hitchings developed an array of new drugs that were effective against leukemia, auto immune disorders, urinary tract infection, gout, malaria, and viral herpes. They revolutionised the way drugs were being developed. Their unique method involved studying the chemical composition of diseased cells. Rather than relying on trial and error methods, they used the differences in biochemistry between normal human cells and pathogens (disease causing agents) to design drugs that block viral infections. Elion also discovered treatments to reduce the body’s rejection of foreign tissue in kidney transplants between unrelated donors. In all, Elion developed 45 patents in medicine. In 1991 she was awarded a National Medal of Science and was inducted into the National Women’s Hall of Fame.

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The Government of India recently launched a mobile app called MANAS to promote mental health. What is special about the app?

What does it stand for?

The name MANAS stands for Mental Health and Normalcy Augmentation System. The app, which is meant to act as a guide, has been developed to promote the mental well-being of people across different age groups in the country. In other words, its objective is to build a happier, healthier community.

A comprehensive, secure, national digital well-being platform, the pilot version of the app was launched by the Principal Scientific Advisor to the Government of India, K. Vijay Raghavan. Endorsed as a national programme, the app was initiated by the Office of the PSA, and jointly executed by NIMHANS (National Institute of Mental Health and Neuro Sciences) Bengaluru, AFMC (Armed Forces Medical College), Pune, and C-DAC (Centre for Development of Advanced Computing), Bengaluru.

The MANAS app integrates the health and wellness efforts of various ministers, national bodies, and research centres. It is based on life skills and psychological processes, and delivers age-appropriate methods to promote positive outlook. It has gamified interfaces to enhance user engagement, supports teleconsultation, and will also be tracking the health of users.

The current version of the app focuses on promoting positive mental health in people aged between 15 and 35, although the ultimate aim is to cover all age groups. The app is not available for public use as yet. According to some reports, field trials will be carried out in the next few months to validate the app.

What is mental health?

If you’ve been wondering what mental health is, the WHO defines it as “a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community”. Our mental health influences how we think, feel, and act, how we handle stress, and how we relate to others. It is important at every stage of our life.

Impact of the pandemic

The COVID-19 pandemic has wreaked havoc in people’s lives. There have been reports of people experiencing increased levels of stress, anxiety, fear, frustration, and depression, owing to loss of income, increased isolation, uncertainty, etc. With the country reeling under a second wave of coronavirus, people are once again forced not to step out of their homes except for essentials, to wear masks, and maintain social distancing. With the closure of schools and colleges, students have largely been confined to their homes. While online classes try to ensure continuity of education, not all can afford it due to a variety of reasons. The prolonged stay at home can mean different impacts and challenges for different sections of people. In these trying, uncertain times, it is hoped that the introduction of the MANAS app will go a long way in helping people and promoting mental well-being.

Cause for concern

• According to a report published in The Lancet Psychiatry last year, there were 197.3 million people (14.3% of the population) with mental disorders in India in 2017.
• Depression and anxiety disorder were found to be top mental illnesses.
• Also 28% of global suicides take place in India.

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The distressing stories of people gasping for breath, not finding oxygen cylinders when they need them has become a recurrent theme during the ongoing COVID-19 pandemic. The function of oxygen in our healthy living can’t be stressed enough and times such as these offer us a stark reminder.

You must be aware of the workings of the heart and the lungs in our bodies. Among other things, they are responsible for supporting the circulation of blood through the body. And it is this blood that carries oxygen to the various parts of the body.

Need for substitutes

While all this takes place seamlessly in a healthy individual, there are occasions when organs need to be substituted with machines in order to perform certain surgeries. The heart-lung machine is one substitute that temporarily replaces the heart and lungs, making cardiac surgeries possible. An American physician called John Gibbon is to be thanked for the invention of the heart-lung machine.

The distressing stories of people gasping for breath, not finding oxygen cylinders when they need them has become a recurrent theme during the ongoing COVID-19 pandemic. The function of oxygen in our healthy living can’t be stressed enough and times such as these offer us a stark reminder.

You must be aware of the workings of the heart and the lungs in our bodies. Among other things, they are responsible for supporting the circulation of blood through the body. And it is this blood that carries oxygen to the various parts of the body.

Need for substitutes

While all this takes place seamlessly in a healthy individual, there are occasions when organs need to be substituted with machines in order to perform certain surgeries. The heart-lung machine is one substitute that temporarily replaces the heart and lungs, making cardiac surgeries possible. An American physician called John Gibbon is to be thanked for the invention of the heart-lung machine.

Life-changing experience

Gibbon became a research fellow in Edward Churchill’s laboratory at Boston City Hospital. It was during this time that he went through the experience that would inspire him to his invention. In October 1930, Gibbon assisted Dr. Churchill perform a procedure on a young woman. Even though it was unsuccessful, it led Gibbon to think that if they could have “performed part of the work of the patient’s heart and lungs outside the body”, then she could have been saved.

Following this event, Gibbon started performing feline experiments to investigate the possibility of his idea along with Mary Hopkinson, Dr. Churchill’s research assistant, and later Gibbon’s wife. Together, they experimented with cats, trying to obstruct the pulmonary arteries and pump blood through a mechanical lung. It was on May 10, 1935 that the first cat survived as Gibbon’s apparatus was able to successfully maintain its cardiac and respiratory functions. The cat had been kept alive without its own heart using extra-corporeal circulation.

Tireless pursuit

Even though World War II interrupted their work, Gibbon’s quest continued as he tirelessly worked to improve his device to make it suitable for human beings. In the 1940s, Gibbon was able to persuade IBM Corporation to provide the necessary technical expertise to make a more sophisticated device that could be used for humans.

After 18 years of perseverance during which he constantly improved his invention, Gibbon finally performed the first successful open-heart operation on May 6, 1953. Cecilia Bavolek, an 18-year-old woman, underwent successful surgery with Gibbon’s heart-lung machine substituting for her heart and lungs during the course of the operation. She had an uneventful recovery and was discharged home in less than two weeks.

Gibbon’s heart-lung machine was a giant stride towards performing certain successful operative procedures that were previously even unthinkable. In the decades since then, the heart-lung machine has been improved constantly, allowing surgeons today to not only repair defective hearts and their valves, but also perform bypass surgeries and heart transplants.

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SCIENTISTS

Scientists study the Universe in order to find out how and why things happen. There are many different branches of science, such as physics, chemistry, and astronomy. Scientists make careful observations of the phenomena they are studying. They construct possible explanations for their observations, known as theories or hypotheses. Then they experiment to test whether their theories are accurate.

1. SIR ISAAC NEWTON: English physicist and mathematician Newton (1642-1727) proposed the laws of motion that explain how forces move objects, and went on to devise a theory of gravity. Newton also studied optics, the science of light, and explained how white light is made up of many colours.
2. MARIE CURIE: Marie Curie (1867-1934) was born in Poland, but carried out her investigations into radioactivity in Paris with her French husband, Pierre. She discovered the elements (substances) polonium and radium in 1898, and won two Nobel Prizes. Marie Curie died of leukaemia, probably due to long exposure to radiation.
3. LUIGI GALVANI: Italian scientist Galvani (1737-98) studied the role of electrical impulses in animal tissue by experimenting on frogs. Although his theory that the electricity was coming from the animal tissue was wrong, his discoveries led to the invention of the battery by Alessandro Volta.
4. ALBERT EINSTEIN: Einstein (1879-1955) was born in Germany but after Hitler came to power, he fled to the United States. Einstein revolutionized physics with his studies of relativity, which show how matter, energy, space, and time are connected. Einstein was awarded the Nobel Prize for Physics in 1921.
5. ALEC JEFFREYS: British geneticist Jeffreys (born 1950) discovered that each individual has certain distinctive patterns of DNA and worked out how to make images of these DNA sequences. He pioneered DNA fingerprinting, used by forensic scientists in criminal investigations to identify people from traces of DNA.
6. BLAISE PASCAL: Frenchman Pascal (1623-62) explored many practical applications of science and mathematics. He invented a mechanical calculator, a device made up of dials and gears, as well as a type of syringe. He also did experiments with air pressure.
7. GALILEO: Italian astronomer and mathematician, Galileo (1564-1642) was the first person to use a telescope for studying the sky. He discovered the four largest satellites of Jupiter, today known as the Galilean moons.
8. COPERNICUS: Polish astronomer Copernicus (1473-1543) is considered to be the founder of modern astronomy. His studies of the orbits of the planets revealed that the Sun is at the centre of the Solar System. At the time, the predominant view was that Earth was the centre of the Universe.
9. ALESSANDRO VOLTA: In 1800, research into electric currents led Italian physicist Volta (1745-1827) to invent the battery. Volta’s battery or “voltaic pile” was the first reliable means of producing an electric current, and so made it easier to perform further experiments with electricity.
10. BENJAMIN FRANKLIN: US statesman, writer, and scientist Franklin (1706-90) conducted research into electricity. He proved that lightning is an electrical current and suggested the use of lightning conductors to protect buildings from lightning strikes.

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Do you know about the Kuiper Belt in the solar system? A disc-shaped region outside the orbit of Neptune, the Kuiper Belt consists of a lot of icy objects. Apart from being home to plenty of celestial objects and minor planets, the region also produces many comets. It is named after astronomer Gerard Kuiper, who speculated about the existence of such a disc decades before it was actually observed.

Gifted with great eyesight

Born in 1905 in a village in northern Holland, Kuiper was meant to be an astronomer from birth. For he was gifted with eyesight that was the envy of other star gazers. His sharp eyesight meant that he could see some stars with his naked eye that others could only dream of, as these stars were nearly four times fainter than stars that are normally visible to us in the sky. Kuiper had his eyes to the skies from an early age and it was no wonder that he took to astronomy.

He began studying at Leiden University, where the renowned 17th Century Dutch astronomer Christiaan Huygens had also studied, in 1924. The period saw many astronomers flock to the university, meaning Kuiper built friendships with quite a few who went on to make useful contributions to astronomy.

By 1927, Kuiper received his B.Sc. in Astronomy. He finished his doctoral thesis on binary stars in 1933, travelled to the U.S. the same year and became an American citizen in 1937. He started as a fellow at the Lick Observatory in California and went on to work at the Harvard College Observatory, Yerkes Observatory of the University of Chicago, and the University of Arizona.

A hard worker who demanded the same kind of devotion and dedication from everyone around him, Kuiper made a number of discoveries that advanced the field of planetary science. Kuiper focussed on planets and objects in the solar system at a time when most astronomers showed little interest in these topics.

In 1947, Kuiper predicted correctly that carbon dioxide is a major component of Mars’ atmosphere. In that same year, he also correctly predicted that the rings of Saturn are composed of ice particles, and discovered Miranda, Uranus’ fifth moon.

In 1949, he discovered Nereid, Neptune’s moon. He also proposed a theory for the origin of the solar system in that year. He suggested that planets had been formed by the condensation of a large cloud of gas around the sun.

Belt that bears his name

It was in 1951 that he proposed the existence of what we now call the Kuiper Belt in an article for the journal Astrophysics. Even though he wasn’t the first to think of the idea (Irish astronomer, engineer and economist Kenneth Edgeworth had proposed the existence of such a disc of bodies), it is Kuiper’s name that is now associated with it.

Kuiper not only used this idea to offer an explanation as to why there were no large planets beyond Neptune, but also suggested that objects from this disc wandered into the solar system as a comet, thereby explaining their origins as well.

Apart from these, Kuiper was also able to prove in 1956 that Mars’ polar ice caps were not made up of carbon dioxide as had been previously believed, but were actually composed of frozen ice. He also predicted in 1964 that our moon’s surface would be “like crunchy snow” to walk on, something that was later verified by U.S. astronaut Neil Armstrong in 1969.

Influential role

Kuiper’s role was influential in the development of infrared airborne astronomy in the 1960s and 1970s. Using these, Kuiper studied the spectroscopy of the sun, stars and planets, something impossible from ground-based observatories.

By the time Kuiper died in 1973, he had left an indelible mark on astronomy. His name, in fact, is now literally on the moon, Mercury and Mars, as craters in these bodies have been named after him. His contributions and discoveries have led many to view him as the father of modern planetary science.

More about Nereid

Nereid, Neptune’s moon, is named after the Nereids, which are sea-nymphs in Greek mythology. It was Kuiper who proposed the name following his discovery on May 1, 1949.

Kuiper made the discovery using a ground-based telescope. It was the last of Neptune’s satellites to be discovered until Voyager 2’s discoveries came about four decades later.

Nereid is among the largest and outermost of Neptune’s known moons with one of the most eccentric orbits for any satellite in our solar system.

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TECHNOLOGY

Technology is the practical use of scientific knowledge to invent tools and make tasks easier. With simple, early technologies, such as the wheel, the invention came first and it was only explained later in scientific terms. Modern technological innovations are usually the result of years of scientific research, financed by commercial organizations.

1. Wheel: The first wheels were used in Mesopotamia (now Iraq).They were made from planks nailed together to form a circle.
2. Writing: In Mesopotamia, records of accounts and lists of goods were scratched on clay tablets, and people used seals with raised images to mark personal property.
3. Paper: The process of paper-making was also invented in China. Rags and plant fibres were mixed with water, beaten to a pulp, then spread out to dry into a sheet.
4. Gunpowder: The explosive properties of gunpowder were first used by the Chinese to produce fireworks and dramatic bangs to frighten enemies rather than kill them.
5. Spectacles: In the 11th century, the Chinese found that curved pieces of glass (tenses) could bend light. Spectacles were not produced until almost 300 years later.
6. Printing: The printing press developed by Johannes Gutenberg used a system of movable type - individual metal letters made quickly and cheaply - allowing books to be mass-produced for the first time.
7. Telescope: The first telescope was a refracting telescope that used two lenses to focus light from distant objects.
8. Steam engine: James Watt’s rotary steam engine provided the power for the factories and mines of the Industrial Revolution by converting the energy in steam into motion.
9. Railway locomotive: The first railway locomotive used a high-pressure steam engine to move a train along rails.
10. Electric generator: Michael Faraday invented the first electric motor, which used electricity to produce motion. He then reversed this process, using motion to produce electricity, thus inventing the electric generator.
11. Photography: The first practical photographic process was invented by Louis Daguerre. Known as the Daguerreotype, it used a copper plate coated with silver and light-sensitive chemicals to capture the image.
12. Telephone: Alexander Graham Bell invented the telephone after discovering that voice vibrations could be converted to electrical signals, sent along a wire, and converted back into sound vibrations at the other end.
13. Light bulb: Joseph Swan and Thomas Edison simultaneously came up with the light bulb, which works by causing a metal filament to glow when an electric current passes through it.
14. Petrol-engine motor car: The first motor car with an internal combustion engine powered by petrol had a U-shaped steel frame and three wheels.
15. Cinema: Brothers Louis and Auguste Lumiere invented a combined camera and projector they called the cinematographe, which projected moving images onto a screen.
16. Aeroplane: Wilbur and Orville Wright built the first successful heavier-than-air, powered aircraft. Their first flight lasted only 12 seconds.
17. Triode valve: First designed to control electric current, the triode valve went on to be used as an amplifier for radio and TV signals, and as “switches” in computers.
18. Radio broadcast: The first public radio broadcasts were heard in 1906. By the mid 1920s, people were buying radio sets for their homes.
19. Television transmission: John Logie Baird produced the first television transmission using a series of spinning discs to produce the image. This mechanical device was soon overtaken by the electronic cathode ray tube.
20. Transistor: The transistor did the same job as a triode valve, but it was smaller, more reliable, and used less power, paving the way for more compact electronic devices.
21. Microchip: This invention integrated thousands of transistors into single miniature chips of silicon, replacing mechanical control devices in household goods and bulky circuits in computers.
22. Communications satellite: The launch of the first communications satellite, Telstar, allowed live television programmers and telephone calls to be transmitted around the world by bouncing signals off the orbiting space satellite to receiver dishes on the ground.
23. Personal computer: The first successful desktop computer, Apple II, had an integrated keyboard, which connected to a television.
24. Mobile phone: Calls are transmitted via a network of short-range local transmitters using radio waves instead of cables.
25. Compact disc: The CD uses a laser to read sound information recorded as a series of pits under the disc’s smooth surface.
26. IPhone: As technology advances, electronic devices become smaller and more intricate. Gadgets, such as Apple’s iPhone, are designed to perform many different functions, including playing music and videos, storing photos, and accessing the Internet.
27. 3-D printer: Unlike ordinary printers, these printers can create three-dimensional (3-D) objects, which have width and height, as well as length, or depth. Regular printers use ink, but 3-D printers mostly use layers of melted plastic to create a model. Metal, chocolate, or even concrete can be used as material to create models.

 

ROBOTS

A robot is a machine that appears to think and act for itself. The simplest type of robot is a mechanical toy, or automaton, which has been programmed to perform a series of actions that usually have no real function. Some robots are remote-controlled devices, guided at a distance by a human operator. The most complex robots have artificial intelligence - an ability to make decisions for themselves, solve problems, and learn.

• SURGEON ROBOT Surgical robots, such as da Vinci, can insert minute instruments and a viewer called an endoscope into an incision just 1 cm (0.4 in) wide. The surgeon studies the operation site on a screen and moves the robot’s instruments by remote control.
• HUMANOIDS Humanoid robots, such as Jia Jia, iCub, and NAO, are created to resemble human beings. They have a head and a face, and while some walk on two legs, others may roll on tracks or wheels.

NAO’s flexibility allows it to play football and perform complex dance routines.

• ANIMAL ROBOTS Robots that imitate the way different types of animals move and behave are vital steps in the development of ranges of movement that may be needed in robots of the future.
• INDUSTRIAL ARMS Most industrial robots are computer-controlled mechanical arms. They do jobs that would be difficult or dangerous for humans, or jobs that require constant repeated actions. A robot can do all these jobs more quickly or accurately than a human - and without needing to rest.
• SPACE TRAVELLERS In space, robot spacecraft and surface vehicles called rovers, such as Mars 2020, are sent to explore places that are too dangerous to send human astronauts. The movements of these robots are pre-programmed or directed from Earth, though the rovers also use camera data to avoid obstacles.
• HELP AT HOME Although no one yet has an android servant doing all the domestic chores, some robots are at work in homes, performing repetitive jobs such as vacuuming floors and mowing lawns. These robots are programmed to avoid hazards in their paths.
• HELPING AT WORK Robots are increasingly equipped to help humans carry out tasks that may be boring, repetitive, or dangerous. They work independently, guided by sensors and cameras, and can sustain themselves in bad weather, tight spaces, and rugged terrain.
• MILITARY ROBOTS Robot vehicles are useful in warfare because they can enter dangerous situations without risking lives. Robot devices conduct surveillance over enemy land and can find and dispose of bombs and landmines while the operator remains at a safe distance.

Picture Credit : Google

TRANSPORT

The world today is constantly on the move. It is impossible to imagine life without the planes, trains, ships, and cars that transport people and goods, every day. Each of these incredible machines has been specifically designed to travel over land, through the air, and under or over the water.

• BY ROAD Most road vehicles have an internal-combustion engine, which burns fuel to make the power that turns the wheels. In a car, the engine is usually in the front and drives either the front or the back wheels. In a motorbike, the engine is placed between the two wheels.
• BY AIR To travel through the air, aircraft must overcome the force of gravity, which pulls them towards the ground. They achieve this with the help of curved wings and rotors, which produce an upward force called lift as they pass through the air.
• BY RAIL Trains carry large cargoes of people or goods and, as a result, are much more fuel-efficient and produce less pollution than cars and lorries. The fastest trains, such as France’s TGV, have electric motors, but most trains are powered by diesel engines. Trains can be pulled by one locomotive (powered vehicle) at the front, but can have two or even more.
• BY SEA As a boat’s weight pushes down on the water, the water pushes back with an upward force, called buoyancy, which supports the boat’s weight, allowing it to float. A submarine submerges by filling tanks with seawater to increase its weight. To surface, it uses air to push water out of the tanks.

Picture Credit : Google

ELECTROMAGNETIC SPECTRUM

Energy spreads in waves of electromagnetic radiation, like the ripples on a pond. It travels through space at the speed of light, around 300,000 km/sec (186,000 miles/sec). Although energy always travels through space at the same speed, its wavelength (the distance between any two peaks or troughs of the waves) can vary. Short waves, such as X-rays, carry high amounts of energy that can penetrate the human body, while longer, lower energy waves, such as light cannot. Apart from visible light, all electromagnetic waves are invisible. Together these waves make up a continuous band of energy known as the electromagnetic spectrum.

GAMMA RAYS Gamma rays are produced by radioactivity, such as a nuclear explosion. They have a short wavelength and carry large amounts of energy. They are very harmful to humans, but are used to treat cancer by killing damaged cells.

X-RAYS These high-energy waves can pass through materials such as flesh and suitcase plastic, but not through bone or metal objects. This makes them a valuable tool for examining bones in hospitals and searching for weapons in airports.

ULTRAVIOLET RAYS With a slightly shorter wavelength than visible violet light, ultraviolet rays also carry more energy than visible light. Ultraviolet rays emitted by the Sun and tanning beds can damage skin not protected by sunblock, causing sunburn.

VISIBLE LIGHT The Sun emits most of its energy as visible light, which can be split into the colours of the rainbow. Earth’s atmosphere allows visible light through, while blocking more harmful wavelengths. Visible light is vital for life. Without it, plants could not grow.

INFRARED RAYS Just beyond the visible red in the spectrum is infrared, which can be felt as heat. Often, when heat energy moves it is transported by infrared waves. Infrared satellite images of Earth’s surface are used by weather forecasters to determine temperatures.

MICROWAVES These have much longer wavelengths than visible light.  Longer wavelength microwaves are used in a microwave oven. Shorter wavelength microwaves are used in radar systems that help ships and planes navigate by locating traffic and obstacles.

RADIO WAVES These are the longest in the spectrum. Many forms of communication, such as TV, mobile phones, and radio, use radio waves, with different wavelengths carrying different signals. Radio waves from outer space are picked up by radio telescopes and used in studies of the Universe.

WAVELENGTHS The difference between wavelengths at either end of the electromagnetic spectrum is immense. The wavelength of gamma rays is only a fraction of the size of an atom, while radio waves at the opposite end of the spectrum can be thousands of kilometres long.

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COLOUR

Light is the visible part of the electromagnetic spectrum. We see different wavelengths of light as different colours. The surfaces of objects absorb some wavelengths and reflect others. A white object looks white because it reflects all the wavelengths that fall on it. A black object absorbs all the wavelengths, so it appears dark.

A yellow object absorbs all the wavelengths except yellow, which it reflects back to our eyes. The band of visible colours that make up light is known as the spectrum. Each shade blends into the next, but we usually divide the spectrum into seven colours: red, orange, yellow, green, blue, indigo, and violet.

SYMBOLISM We use colours as symbols to represent different ideas in culture and religion. However, the meaning of colours may vary. For example, in some cultures brides wear red, whereas in others they wear white.

COMPLEMENTARY COLOURS If the colours of the spectrum are arranged in order on a colour wheel, colours located opposite each other, such as orange and blue, are called complementary colours. When complementary colours are presented side by side, they appear at their brightest.

VIOLET Light at the violet end of the visible spectrum has a shorter wavelength and higher frequency than light at the red end of the spectrum.

REAL COLOURS The light reflected from an object is made up of a range of wavelengths. An object that looks yellow might reflect 80 per cent of the light at the yellow wavelength, but also smaller amounts of other colour wavelengths.

COLOUR BLINDNESS Our ability to detect colours depends on cells on the eye’s retina, which are sensitive to specific wavelengths of light. The cells that detect certain parts of the spectrum are missing or inactive in a colour-blind person.

INTENSITY On a sunny day, things appear colourful because our eyes can see differences in the wavelengths of light. On a dark day, less light enters the eyes, so we cannot distinguish wavelengths as easily and colours look dull.

SPLITTING WHITE LIGHT When white light passes through a block of glass called a prism, different wavelengths refract (bend) different amounts, so the light splits showing the colours of the spectrum. When light passes through raindrops this effect creates a rainbow.

Picture Credit : Google