Category Physics

What is the concept of the first british atomic bomb?

Like it or not, science and technology sees unprecedented growth during dire times. This is probably because funding flows into different branches of science like never before, allowing for progress inconceivable during ordinary times. Just like how the COVID-19 pandemic saw a global collective search for vaccines, there have been other times in the past – mostly during wars – when a number of scientific fields received a tremendous boost.

World War II was one such period when scientific progress was at its pinnacle. The ability to split an atom through nuclear fission was discovered in the 1930s. With its ability to release immense power realised, it wasn’t long before the race to build a bomb with it was on. The Manhattan Project was born early in the 1940s and we all know what happened in Japan’s Hiroshima and Nagasaki.

To retain influence                                           

While the Manhattan Project was led by the U.S., it was done in collaboration with the U.K. along with support from Canada. Following the war, however, the U.S. refused to share atomic information with the U.K. With the objective of avoiding complete dependence on the U.S., and to remain a great power and retain its influence, Britain sought to become a nuclear power.

The prospect was discussed in a secret cabinet committee in October 1946. While Chancellor of the Exchequer Hugh Dalton and President of the Board of Trade Stafford Cripps were opposed to the idea of a British bomb citing the huge costs involved, Secretary of State for Foreign Affairs Ernest Bevin had his way and work went ahead. By the time the bomb was ready, however, Winston Churchill’s government came to power.

Penney at the helm

Led by British mathematician William Penney, who had worked on the world’s first atomic bomb in the U.S., the project that went on to become Operation Hurricane began with a secret laboratory tasked with developing the trigger device. With the Soviets managing to successfully explode their first atomic bomb in 1949, Penney’s team was under further pressure. Soon enough, the Brits were ready with their bomb.

Early in 1951, the Australian government agreed that the blast could take place at the uninhabited Monte Bello islands, an archipelago of over 100 islands lying off the coast of north-western Australia. The region was declared a prohibited zone and ships and aircraft were later warned to stay clear of an area of 23,500 nautical square miles off the coast.

Plym carries the bomb

 The troops were mobilised, the first set of vessels left for their destination in January 1952 and six months later HMS Plym, carrying the bomb, and the fleet flagship HMS Campania, made their way. The radioactive core, which used British and Canadian plutonium, was flown out later, and installed in the bomb on Plym very close to the scheduled detonation.

On the morning of October 3, 1952, Britain’s first atomic bomb exploded, sending thousands of tonnes of rock, mud, and sea-water blasting into the air. The Plym was instantly vaporised, with scant bits of red-hot metal from the vessel falling on one of the islands even starting a fire.

An eye-witness account of a Reuters correspondent stationed less than 100 miles away mentions a grand flash followed by the appearance of a grey cloud-a zigzag Z-shaped cloud as opposed to the mushroom cloud that we instantly associate with such detonations.

The success of Operation Hurricane resulted in Penney being knighted. Churchill, who was serving as the Prime Minister of the U.K. for a second time, announced to the House of Commons that there had been no casualties and that everything had gone according to plan. While he did congratulate the Labour Party for their role in the whole project, he also did take a dig at them saying that ‘as an old parliamentarian I was rather astonished that something well over £100 million could be disbursed without Parliament being made aware of it.’

Like it or not, science and technology sees unprecedented growth during dire times. This is probably because funding flows into different branches of science like never before, allowing for progress inconceivable during ordinary times. Just like how the COVID-19 pandemic saw a global collective search for vaccines, there have been other times in the past – mostly during wars – when a number of scientific fields received a tremendous boost.

World War II was one such period when scientific progress was at its pinnacle. The ability to split an atom through nuclear fission was discovered in the 1930s. With its ability to release immense power realised, it wasn’t long before the race to build a bomb with it was on. The Manhattan Project was born early in the 1940s and we all know what happened in Japan’s Hiroshima and Nagasaki.

To retain influence                                           

While the Manhattan Project was led by the U.S., it was done in collaboration with the U.K. along with support from Canada. Following the war, however, the U.S. refused to share atomic information with the U.K. With the objective of avoiding complete dependence on the U.S., and to remain a great power and retain its influence, Britain sought to become a nuclear power.

The prospect was discussed in a secret cabinet committee in October 1946. While Chancellor of the Exchequer Hugh Dalton and President of the Board of Trade Stafford Cripps were opposed to the idea of a British bomb citing the huge costs involved, Secretary of State for Foreign Affairs Ernest Bevin had his way and work went ahead. By the time the bomb was ready, however, Winston Churchill’s government came to power.

Penney at the helm

Led by British mathematician William Penney, who had worked on the world’s first atomic bomb in the U.S., the project that went on to become Operation Hurricane began with a secret laboratory tasked with developing the trigger device. With the Soviets managing to successfully explode their first atomic bomb in 1949, Penney’s team was under further pressure. Soon enough, the Brits were ready with their bomb.

Early in 1951, the Australian government agreed that the blast could take place at the uninhabited Monte Bello islands, an archipelago of over 100 islands lying off the coast of north-western Australia. The region was declared a prohibited zone and ships and aircraft were later warned to stay clear of an area of 23,500 nautical square miles off the coast.

Plym carries the bomb

 The troops were mobilised, the first set of vessels left for their destination in January 1952 and six months later HMS Plym, carrying the bomb, and the fleet flagship HMS Campania, made their way. The radioactive core, which used British and Canadian plutonium, was flown out later, and installed in the bomb on Plym very close to the scheduled detonation.

On the morning of October 3, 1952, Britain’s first atomic bomb exploded, sending thousands of tonnes of rock, mud, and sea-water blasting into the air. The Plym was instantly vaporised, with scant bits of red-hot metal from the vessel falling on one of the islands even starting a fire.

An eye-witness account of a Reuters correspondent stationed less than 100 miles away mentions a grand flash followed by the appearance of a grey cloud-a zigzag Z-shaped cloud as opposed to the mushroom cloud that we instantly associate with such detonations.

The success of Operation Hurricane resulted in Penney being knighted. Churchill, who was serving as the Prime Minister of the U.K. for a second time, announced to the House of Commons that there had been no casualties and that everything had gone according to plan. While he did congratulate the Labour Party for their role in the whole project, he also did take a dig at them saying that ‘as an old parliamentarian I was rather astonished that something well over £100 million could be disbursed without Parliament being made aware of it.’

Picture Credit Google

what’s phantom electricity?

 Do you always switch off appliances when not in use? Now, do you remove these from their sockets? Did you know that even when you have switched off the appliance, some of the appliances can consume power in standby mode? The phantom electricity or vampire electricity is just that. It is the electricity that some gadgets consume when they are in standby power mode or switched off.

Note that those devices that do not have clocks and dashboards do not consume vampire energy. An example of a device that consumes vampire electricity includes water coolers.

Nowadays the water cooler is always running and will require a large amount of energy. Other examples include vending machines, coffee makers, laptop chargers, microwaves, security cameras, televisions, surround sound systems, gaming consoles, washing machines, dishwashers, photocopiers, cordless landline phones, battery chargers, mobile phones, and so on. These devices consume energy 24/7 when they are plugged into outlets. While we may have to keep some devices left on or on standby such as the fridge, most appliances need not be.           

According to experts, vampire energy consumption can be around 40% of a building’s energy use. Some studies have found that more than 100 billion kilowatt-hours get wasted due to phantom electricity every year. Further, it can also produce some 80 million tonnes of carbon dioxide. Residential waste and industrial vampire energy consumption are significant contributors to these emissions. The problem is with always-on devices. So the combined effect of the phantom electricity is much higher. Further, the percentage of phantom power use has burgeoned in recent years, more so because we have more appliances in our homes and industrial spaces. So all the devices combined, the loss of power through phantom load can be a significant amount. This means higher utility bills and more carbon pollution. Identify the devices that are invisibly draining the electricity in your home and cut down on phantom power usage.

Now what can you do if you aren’t sure if the appliance consumes standby power? Well, you can prevent this wastage of energy by just unplugging the device!

Picture Credit : Google

What is the concept of the first british atomic bomb?

Like it or not, science and technology sees unprecedented growth during dire times. This is probably because funding flows into different branches of science like never before, allowing for progress inconceivable during ordinary times. Just like how the COVID-19 pandemic saw a global collective search for vaccines, there have been other times in the past – mostly during wars – when a number of scientific fields received a tremendous boost.

World War II was one such period when scientific progress was at its pinnacle. The ability to split an atom through nuclear fission was discovered in the 1930s. With its ability to release immense power realised, it wasn’t long before the race to build a bomb with it was on. The Manhattan Project was born early in the 1940s and we all know what happened in Japan’s Hiroshima and Nagasaki.

To retain influence                                                                

While the Manhattan Project was led by the U.S., it was done in collaboration with the U.K. along with support from Canada. Following the war, however, the U.S. refused to share atomic information with the U.K. With the objective of avoiding complete dependence on the U.S., and to remain a great power and retain its influence, Britain sought to become a nuclear power.

The prospect was discussed in a secret cabinet committee in October 1946. While Chancellor of the Exchequer Hugh Dalton and President of the Board of Trade Stafford Cripps were opposed to the idea of a British bomb citing the huge costs involved, Secretary of State for Foreign Affairs Ernest Bevin had his way and work went ahead. By the time the bomb was ready, however, Winston Churchill’s government came to power.

Penney at the helm

Led by British mathematician William Penney, who had worked on the world’s first atomic bomb in the U.S., the project that went on to become Operation Hurricane began with a secret laboratory tasked with developing the trigger device. With the Soviets managing to successfully explode their first atomic bomb in 1949, Penney’s team was under further pressure. Soon enough, the Brits were ready with their bomb.

Early in 1951, the Australian government agreed that the blast could take place at the uninhabited Monte Bello islands, an archipelago of over 100 islands lying off the coast of north-western Australia. The region was declared a prohibited zone and ships and aircraft were later warned to stay clear of an area of 23,500 nautical square miles off the coast.

Plym carries the bomb

 The troops were mobilised, the first set of vessels left for their destination in January 1952 and six months later HMS Plym, carrying the bomb, and the fleet flagship HMS Campania, made their way. The radioactive core, which used British and Canadian plutonium, was flown out later, and installed in the bomb on Plym very close to the scheduled detonation.

On the morning of October 3, 1952, Britain’s first atomic bomb exploded, sending thousands of tonnes of rock, mud, and sea-water blasting into the air. The Plym was instantly vaporised, with scant bits of red-hot metal from the vessel falling on one of the islands even starting a fire.

An eye-witness account of a Reuters correspondent stationed less than 100 miles away mentions a grand flash followed by the appearance of a grey cloud-a zigzag Z-shaped cloud as opposed to the mushroom cloud that we instantly associate with such detonations.

The success of Operation Hurricane resulted in Penney being knighted. Churchill, who was serving as the Prime Minister of the U.K. for a second time, announced to the House of Commons that there had been no casualties and that everything had gone according to plan. While he did congratulate the Labour Party for their role in the whole project, he also did take a dig at them saying that ‘as an old parliamentarian I was rather astonished that something well over £100 million could be disbursed without Parliament being made aware of it.’

Picture Credit : Google

What are bubbletrons?

While it is nearly impossible to say with certainty, the moments following the Big Bang will probably be unmatched in the universe. We do know that it featured the most energetic and transformative events that have ever Occurred.

A new study published on the preprint database arxiv on June 27 suggests that massive bubbles emerged and collided with each other, may have powering up colossal energies in the early universe. The researchers are calling these ultra-energetic, early universe structures as “bubbletrons.”

Four fundamental forces of nature

 There are four fundamental forces of nature – electromagnetism, strong nuclear, weak nuclear and gravity. These, however, aren’t always different and they tend to merge at high energies. Powerful particle colliders have already detected electromagnetism and the weak nuclear force merging into a “electroweak” force.

Even though there is no proof, physicists suspect that all forces could merge into a single, unified force at extremely high energies. The only time the universe had such energies, however, was in the moments after the Big Bang. The splitting of the forces from those instances might have either been serene and smooth, or incredibly violent.

Extraordinary amounts of energy

This research suggests that if the transitions had indeed been violent, then the universe could have been filled with gigantic bubbles, only briefly. Before eventually colliding, expanding and converting the universe into the new reality, these bubbles would have carried extraordinary amounts of energy. According to the researchers, the bubbletrons could have in fact reached the energies required to trigger the formation of hypothetical dark matter. The researchers also discovered that the expansion and collision of these bubbletrons would have created gravitational waves capable of persisting till this day.

A recent research has already expressed that our universe is flooded with a background hum of gravitational waves. Even though most of these are likely due to supermassive black holes colliding, some might be a result of other processes in the early universe, including the creation and distortion of bubbletrons. Future analysis and upcoming gravitational wave detectors might be able to provide evidence for the existence of bubbletrons.

Picture Credit : Google 

Unsung pioneers in the field of science

These are tales not just of perseverance and love for science, but also of discrimination and unfair treatment. Despite making groundbreaking discoveries, their names remain largely unknown, simply because they are women. Let's celebrate these women scientists and their contribution to the world….

ESTHER MIRIAM ZIMMER LEDERBERG (1922-2006)

Esther Miriam Zimmer Lederberg was an American microbiologist, who discovered bacterial virus Lambda phage and the bacterial fertility factor F (F plasmid). Like many woman scientists of her time, Esther Lederberg was not given credit for her scientific contribution because of her gender. While her husband, her mentor and another research partner won 1958 Nobel Prize in Physiology or Medicine for discovering how genetic material is transferred between bacteria, Esther wasn't even mentioned in the citation, even though her work significantly contributed to the discovery.

Esther Miriam Lederberg was born in Bronx, New York, into a humble family. When studying masters in genetics at Stanford University, Esther struggled to make ends meet. As recollected by Esther in her interviews, she had sometimes eaten frogs’ legs leftover from laboratory dissections.

Esther met her future husband Joshua Lederberg at Stanford. They moved to the University of Wisconsin, where they would begin years of collaboration. Throughout the 1950s, they published papers together and apart, as both made discoveries about bacteria and genetics of bacteria.

Esther Lederberg's contributions to the field of microbiology were enormous. In 1950, she discovered the lambda phage, a type of bacterial virus, which replicates inside the DNA of bacteria. She developed an important technique known as replica plating, still used in microbiology labs all over the world. Along with her husband and other team members, she discovered the bacterial fertility factor.

CECILIA PAYNE-GAPOSCHKIN (1900-1979)

Cecilia Payne-Gaposchkin was a British-born American astronomer who was the first to propose that stars are made of hydrogen and helium.

Cecilia Payne was born in 1900 in Buckinghamshire, England. In 1919, she got a scholarship to study at Newnham College, Cambridge University, where she initially studied botany, physics, and chemistry. Inspired by Arthur Eddington, an English astronomer, she dropped out to study astronomy.

Studying astronomy at Cambridge in the 1920s was a lonely prospect for a woman. Cecilia sat alone, as she was not allowed to occupy the same rows of seats as her male classmates. The ordeal did not end there. Because of her gender, Cecilia was not awarded a degree, despite fulfilling the requirements in 1923. (Cambridge did not grant degrees to women until 1948.)

Finding no future for a woman scientist in England, she headed to the United States, where she received a fellowship to study at Haward Observatory. In her PhD thesis, published as Stellar Atmospheres in 1925, Cecilia showed for the first time how to read the surface temperature of any star from its spectrum. She also proposed that stars are composed mostly of hydrogen and helium. In 1925, she became the first person to earn a PhD in astronomy. But she received the doctorate from Radcliffe College, since Harvard did not grant doctoral degrees to women then. She also became the first female professor in her faculty at Harvard in 1956.

Cecilia contributed widely to the physical understanding of the stars and was honoured with awards later in her lifetime.

CHIEN-SHIUNG WU (1912-1997)

Chien-Shiung Wu is a Chinese-American physicist who is known for the Wu Experiment that she carried out to disprove a quantum mechanics concept called the Law of Parity Conservation. But the Nobel Committee failed to recognise her contribution, when theoretical physicists Tsung-Dao Lee and Chen Ning Yang, who had worked on the project, were awarded the Prize in 1957.

Chien-Shiung Wu was born in a small town in Jiangsu province, China, in 1912. She studied physics at a university in Shanghai and went on to complete PhD from the University of California, Berkeley in 1940.

In 1944, during WWII, she joined the Manhattan Project at Columbia University, focussing on radiation detectors. After the war, Wu began investigating beta decay and made the first confirmation of Enrico Fermi's theory of beta decay. Her book "Beta Decay," published in 1965, is still a standard reference for nuclear physicists.

In 1956, theoretical physicists Tsung Dao Lee and Chen Ning Yang approached Wu to devise an experiment to disprove the Law of Parity Conservation, according to which two physical systems, such as two atoms, are mirror images that behave in identical ways. Using cobalt-60, a radioactive form of the cobalt metal, Wu's experiment successfully disproved the law.

In 1958, her research helped answer important biological questions about blood and sickle cell anaemia. She is fondly remembered as the "First Lady of Physics", the "Chinese Madame Curie" and the "Queen of Nuclear Research”.

LISE MEITNER (1878-1968)

Lise Meitner was an Austrian-Swedish physicist, who was part of a team that discovered nuclear fission. But she was overlooked for the Nobel Prize and instead her research partner Otto Hahn was awarded for the discovery.

Lise Meitner was born on November 7, 1878, in Vienna. Austria had restrictions on women education, but Meitner managed to receive private tutoring in physics. She went on to receive her doctorate at the University of Vienna. Meitner later worked with Otto Hahn for around 30 years, during which time they discovered several isotopes including protactinium-231, studied nuclear isomerism and beta decay. In the 1930s, the duo was joined by Fritz Strassmann, and the team investigated the products of neutron bombardment of uranium.

In 1938, as Germany annexed Austria, Meitner, a Jew, fled to Sweden. She suggested that Hahn and Strassmann perform further tests on a uranium product, which later turned out to be barium. Meitner and her nephew Otto Frisch explained the physical characteristics of this reaction and proposed the term 'fission' to refer to the process when an atom separates and creates energy. Meitner was offered a chance to work on the Manhattan Project to develop an atomic bomb. However, she turned down the offer.

JANAKI AMMAL (1897-1984)

Janaki Ammal was an Indian botanist, who has a flower- the pink-white Magnolia Kobus Janaki Ammal named after her.

She undertook an extraordinary journey from a small town in Kerala to the John Innes Horticultural Institute at London. She was born in Thalassery, Kerala, in 1897.

Her family encouraged her to engage in intellectual pursuit from a very young age. She graduated in Botany in Madras in 1921 and went to Michigan as the first Oriental Barbour Fellow where she obtained her DSc in 1931. She did face gender and caste discrimination in India, but found recognition for her work outside the country.

After a stint at the John Innes Horticultural Institute at London, she was invited to work at the Royal Horticulture Society at Wisley, close to the famous Kew Gardens. In 1945, she co-authored The Chromosome Atlas of Cultivated Plants with biologist CD Darlington. Her major contribution came about at the Sugarcane Breeding Station at Coimbatore, Tamil Nadu. Janaki's work helped in the discovery of hybrid varieties of high-yielding sugarcane. She also produced many hybrid eggplants (brinjal). She was awarded Padma Shri in 1977.

GERTY CORI (1896-1957)

Gerty Cori was an Austrian-American biochemist, known for her discovery of how the human body stores and utilises energy. In 1947, she became the first woman to be awarded the Nobel Prize in Physiology or Medicine and the third woman to win a Nobel.

Gerty Theresa Cori was born in Prague in 1896. She received the Doctorate in Medicine from the German University of Prague in 1920 and got married to Carl Cori the same year.

Immigrating to the United States in 1922, the husband-wife duo joined the staff of the Institute for the Study of Malignant Disease, Bualo. N.Y. Working together on glucose metabolism in 1929, they discovered the 'Cori Cycle' the pathway of conversion of glycogen (stored form of sugar) to glucose (usable form of sugar). In 1936, they discovered the enzyme Phosphorylase, which breaks down muscle glycogen, and identified glucose 1-phosphate (or Cori ester) as the first intermediate in the reaction.

The Coris were consistently interested in the mechanism of action of hormones and they carried out several studies on the pituitary gland. In 1947, Gerty Cori, Carl Cori and Argentine physiologist Bernardo Houssay received the Nobel Prize in 1947 for their discovery of the course of the catalytic conversion of glycogen.

Although the Coris were equals in the lab, they were not treated as equals. Gerty faced gender discrimination throughout her career. Few institutions hired Gerty despite her accomplishments, and those that did hire, did not give her equal status or pay.

Picture Credit : Google 

Can sound travel through empty space? Let’s find out by an experiment.

What you need:

Empty glass bottle with a cap, small bell, short firm wire, adhesive tape, matches, and paper

What you do:

  • Attach the bell to the piece of wire. Fix the opposite end of the wire to the inside of the bottle cap with tape. Check if the bell rings when you shake the wire.
  • Screw the cap onto the bottle. Shake the bottle to ensure that the bell jingles inside without touching the sides of the bottle.
  • Unscrew the cap. Tear the paper into shreds and drop the pieces into the bottle.
  • Light two matches and drop them into the bottle. As soon as you do this, quickly screw on the cap with the bell. (Take the help of an adult to do this step.)
  • Wait till the matches and the shredded paper burn out and the bottle cools.
  • Shake the bottle. Can you hear the bell?
  • Open the cap to let in some air and screw it on again. Shake the bottle again. Can you hear the bell now?

What do you observe?

You can hear the bell faintly immediately after the matches extinguish. After you open the cap and screw it on again, you can hear the bell ring louder.

Why does this happen?

Sound needs a medium like air or water to travel through. Sound waves vibrate the particles of the medium. When these vibrations reach our eardrums, we hear sound.

In the experiment, the burning paper and matches used up the oxygen in the sealed bottle, creating a partial vacuum. As sound cannot travel in a vacuum, you cannot hear the bell well until you let in some air into the bottle.

Picture Credit : Google 

Who received India’s first Nobel Prize for physics?

Sir Chandrasekhara Venkata Raman was an Indian physicist known for his work in the field of light scattering. CV Raman was India's first physicist to win a Nobel Physics Prize in 1930 “for his work on the scattering of light and for the discovery of the effect named after him".

Nobel Prize-winning Sir CV. Raman is known for his pioneering work in Physics. India celebrates National Science Day on February 28 each year to mark the discovery of the Raman Effect on the day in 1928.

Sir Chandrasekhara Venkata Raman, also known as C.V. Raman, was a pioneering physicist. Born on November 7, 1888, he was a precocious child, who excelled in Physics during his student days at Presidency College, and later, at the University of Madras. He is best known for his discovery of the Raman Effect, which is a phenomenon of scattering of light that occurs when light passes through a transparent medium. This discovery revolutionised the field of spectroscopy and earned him the Nobel Prize in Physics in 1930.

Raman was born in Tiruchirapalli in Tamil Nadu. He showed an early aptitude for mathematics and science. He graduated from Presidency College in Madras with a degree in Physics and went on to work at the Indian Finance Service. However, he soon realised that his true passion was in Physics and left his job to pursue a career in research at the Indian Association for the Cultivation of Science. It was here that he was given an opportunity to mentor research scholars from several universities, including the University of Calcutta.

He was appointed as Director (first Indian) of the Indian Institute of Science, Bangalore, in 1933. In 1947, he was appointed the first National Professor of independent India. He retired from the Indian Institute in 1948. About a year later, he established the Raman Research Institute in Bangalore.

Raman was not only a brilliant scientist, but also a visionary. He believed that science should be accessible to all people, regardless of their background or social status. He was instrumental in the founding of several science institutions. His aim was to encourage the study of science in India.

In addition to the Nobel Prize, Raman received many other honours and awards throughout his career. He was elected a Fellow of the Royal Society in London in 1924 and was conferred the knighthood by the British government in 1929. He also received numerous awards and honours from the Indian government, including the Bharat Ratna in 1954. India celebrates National Science Day on February 28 each year to mark the discovery of the Raman Effect on the day in 1928.

Raman passed away on November 21, 1970, at the age of 82. He is remembered as one of India's greatest scientists and is still widely celebrated as a pioneer in the field of physics. His legacy continues to inspire young scientists and researchers, who continue to build on his work to expand our understanding of the world around us.

Picture Credit : Google 

Who was Maria Montessori?

It was Italian physician and educator Maria Montessori who pioneered the Montessori method of teaching for children.

For over a hundred years, the Montessori Method has been a favoured way of shaping the first learning experiences of young children. And it is all because of the efforts of a pioneering Italian educator, Maria Montessori (1870-1952).

A bright student, Maria had wanted to study medicine but was rejected by the University of Rome because of her gender. It was only after she earned a degree in natural sciences and a recommendation from the Pope that she was grudgingly given admission. During the course, she was not allowed to attend the anatomy class with the other students as it was deemed inappropriate for a woman to see a naked body in the presence of men. So she had to practise her dissections of bodies alone, after class hours.

Nevertheless, she graduated with flying colours, becoming one of the earliest Italian women to receive a medical degree in 1896.

Maria began her career by working with children in mental asylums. She devised new educational methods for them, which were so successful that her students passed the examinations meant for normal children!

In 1907, she opened Casa dei Bambini (Children’s House) in a slum in Rome, her first chance to see if her methods worked on normal children. She believed that children learned best through doing. She encouraged them to use their five senses to explore their surroundings while playing. She gave them special toys and lessons to develop their innate creativity and imagination.

Maria found that children learned to write before they learned to read. Once, in a class of children who had begun to write a little, she wrote on the blackboard. If you can read this, come up and give me a kiss and waited. Many days passed and then a little girl suddenly went up to her and said, “Here I am!” and kissed her. The children in her schools learnt to read and write by the time they were five years old.

Today Montessori education is followed in over 25,000 schools in more than 140 countries.

Picture Credit : Google 

Scientists have achieved the world’s first X-ray signal (or signature) of just one atom

From medical examinations and airport screenings to space missions, X-rays have been used everywhere since its discovery by German physicist Wilhelm Roentgen in 1895. A group of scientists from Ohio University, Argonne National Laboratory, the University of Illinois-Chicago, and others, have now taken the world's first X-ray signal (or signature) of a single atom. The groundbreaking achievement could revolutionise the way in which scientists detect the materials.

One atom at a time

Before this, the smallest amount one can X-ray a sample is an attogram, which is about 10,000 atoms or more. The paper brought out by the scientists was published in the scientific journal Nature on May 31, 2023 and also made it to the cover of the print edition on June 1. The paper details how physicists and chemists used a purpose-built synchrotron X-ray instrument at the XTIP beamline of Advanced Photon Source and the Center for Nanoscale Materials at Argonne National Laboratory.

Specialised detector

The team involved picked an iron atom and terbium atom for their demonstration. Both atoms were inserted in respective molecular hosts. Conventional detectors were supplemented with a specialised detector by the research team.

This specialised detector was made of a sharp metal tip. It is positioned at extreme proximity to the sample, enabling it to collect X-ray excited electrons. This technique is known as synchrotron X-ray scanning tunnelling microscopy or SX-STM.

Apart from achieving the X-ray signature of an atom, the team also succeeded in another key goal. This was to employ their technique to find out the environmental effect of a single rare-earth atom.

The scientists were able to detect the chemical states of the individual atoms inside respective molecular hosts and compare them. While the terbium atom, a rare-earth metal, remained rather isolated and didn't change its chemical state, the iron atom interacted with its surrounding strongly.

Many rare-earth materials are used in everyday devices like cell phones, televisions, and computers. This discovery allows scientists to not only identify the type of element, but also its chemical state. Knowing this enables them to work on these materials inside different hosts, paving the way for further advancement of technology.

This team aims to continue to use X-ray to detect properties of a single atom. They are also seeking ways to revolutionise their applications so that they can be put to use in critical materials research.

Picture Credit : Google 

What does Hawking’s final theory reveal about the origin of time?

In 1998, physicist Stephen Hawking asked Belgian cosmologist Thomas Hertog to work with him to develop “a new quantum theory of the Big Bang”. What started as a doctoral project for Hertog turned into an intense collaboration that continued until Hawking’s death in 2018. Their answers to the question of how the Big Bang created conditions so perfect for life is what makes the recent book On the Origin of Time: Stephen Hawking’s Final Theory.

In their quest to rethink cosmology from an observers perspective, they had to adopt the strange rules of quantum mechanics that govern the micro-world of atoms and particles. A property called superposition in quantum mechanics suggests that particles can be in several positions at the same time. Only when observed does it randomly pick a specific location. In addition, quantum mechanics also involves random jumps and fluctuations.

Quantum universe

In a quantum universe, therefore, the past and the future emerge from a number of possibilities by continuous observations. These refer to not just the observations done by us human beings, but even the environment or a single particle can “observe”. All other possibilities become irrelevant once something has been observed.

Hawking and Hertog discovered that looking back at the earliest stages of the universe through a quantum lens gave it a more Darwinian flavour of variation and selection. In this deeper level of meta-evolution, even the laws of physics change and evolve in sync with the universe that is taking shape.

Laws evolve

While cosmologists usually start by assuming initial conditions and the laws that existed at the time of the Big Bang, Hawking and Hertog suggest that the laws themselves are a result of evolution. This means that the specific set of physical laws that govern our universe can only be understood in retrospect.

When reasoning back in time, therefore, evolution focussed towards greater simplicity and lesser structure continues all the way. This forms the crux of their hypothesis, meaning that ultimately even time and physical laws would fade away.

The study of the origin of the universe over the last 100 years or so has been against the backdrop of immutable laws of nature. Hawking and Hertog suggest that it isn’t these laws themselves, but their ability to transmute that dictates terms. If future cosmological observations find evidence of this, Hawking’s final theory might well be his greatest scientific legacy.

Picture Credit : Google 

Who is Prof. Shiraz Naval Minwalla?

Meet the $100,000 prize winner of the New Horizon Prize in Physics, Prof. Shiraz Naval Minwalla. He is a theoretical physicist who works with string theory and quantum field theory. He is noted for connecting the equations of fluid dynamics and Einstein’s equations of relativity.

He hails from Mumbai. After completing his Masters in Physics from IIT-Kanpur, he went to Princeton University, U.S.A. for his PhD. He was a junior Fellow at the Harvard Society of Fellows and then served as assistant professor for five years. After that he joined the Department of Theoretical Physics at the Tata Institute of Fundamental Research (TIFR), Mumbai.

He won the Shanti Swarup Bhatnagar Award in 2011 and Infosys Prize in Physical sciences in 2013. He also got the TWAS prize in 2016.

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Who is Dr. Anil Bhardwaj?

Dr. Anil Bhardwaj has made significant contributions as an astrophysicist. He serves as the Director of the Physical Research Laboratory in Ahmedabad, which is a unit of the Department of Space, of the Government of India.

Dr. Anil Bhardwaj received his M.Sc from Lucknow University and PhD from the Indian Institute of Technology (BHU) Varanasi. He joined ISRO as a scientist at the Space Physics Laboratory (SPL) of the Vikram Sarabhai Space Centre (VSSC) in Trivandrum. He rose to become the Director of SPL.

SPL’s research in planetary science was initiated by Dr. Bhardwaj, and he contributed greatly in developing planetary science programs in ISRO. He acted as the Principal Investigator (PI) of the SARA (Sub-keV Atom Reflecting Analyzer) experiment on Chandrayaan-1, India’s first Lunar mission. The new findings changed our understanding on the interaction of solar wind with the Moon.

He has played a key role in many space missions of ISRO. He got the ISRO Team Achievement Award for Chandrayaan-1. He has also won the most coveted Shanti Swarup Bhatnagar Prize (2007) and the Infosys Prize in Physical Sciences (2016).

Dr. Bhardwaj was the editor- in-chief of Advances in Geosciences for seven years, and was among the editors of the European journal Planetary and Space Science, the Bulletin of Astronomical Society of India and Current Science, a journal published by Current Science Association and Indian Academy of Sciences.

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Why is Dr. Jagadish Shukla famous?

Dr. Jagadish Shukla was born in a small village, Mirdha, in Uttar Pradesh. The village had no electricity, not even proper roads. The primary school did not have a building, and Jagadish Shukla had his early classes under a large banyan tree! He could not study science in high school because the schools did not include it.

He went to Banaras Hindu University (BHU) and graduated in Physics, Mathematics and Geology. He did MS in Geophysics and then finished his PhD too. Later he got a ScD (Doctor of Science) in Meteorology from the Massachusetts Institute of Technology (MIT).

He chose a career in the atmospheric sciences and became a professor at George Mason University in the U.S.

Dr. Shukla’s study areas include the Asian monsoon dynamics, deforestation and desertification. Do you know what is desertification? It is when the soil loses its quality due to weather or human activity.

Dr. Shukla helped establish weather and climate research centres in India. He also established research institutions in Brazil and the U.S. He has been with the World Climate Research Programme since its start and founded the Centre for Ocean- Land-Atmosphere Studies, Virginia, U.S.

He has also established the Gandhi College in his village for educating rural students, especially women, and was awarded Padma Shri in 2012.

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What made Atish Dabholkar a famous theoretical physicist?

Atish Dabholkar is a theoretical physicist who researches on string theory and quantum black holes.

String theory says that reality is made up of vibrating strings that are smaller than atoms and electrons, whereas, black holes are regions in space with very heavy mass. One can say they eat up everything that enter it. Due to their high gravitational pull even light cannot escape from them. Now, quantum black holes are hypothetical tiny black holes, a concept that was introduced by Stephen Hawking.

Atish Dhabolkar is presently the Director of the Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy. He is a graduate of IIT-Kanpur. He did PhD in theoretical physics from Princeton University, U.S. Then he did postdoctoral studies and further research at Rutgers University, Harvard University and the California Institute of Technology.

He worked as a professor at the Tata Institute of Fundamental Research in Mumbai. He also served as a visiting professor at Stanford University, US, and was a visiting scientist at CERN, Geneva, Switzerland. He joined ICTP in 2014.

He has received many honours, including the Shanti Swarup Bhatnagar Award (2006). He was awarded the Chaire d’Excellence of the Agence Nationale de la Recherche in France the next year. He is also a recipient of the National Leadership award from the President of India in 2008. The World Academy of Sciences (TWAS), Italy, elected him as a Fellow last year.

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Why is Samir K. Brahmachari an important figure on the scientific stage in India?

Samir K. Brahmachari is a biophysicist who is among the first in utilizing computational tools for genome analysis. He has developed many bioinformatics tools. His research led to the creation of the genetic profile of Indians known as the Indian Genome Variation Project. This was later extended to include all East Asian countries.

He was the first to market the novel, globally competitive bio-informatics software products from CSIR. He has 12 patents, 23 copyrights and 155 research publications to his credit.

Brahmachari did BSc and MSc in chemistry from the University of Calcutta. He earned a PhD in Molecular Biophysics from the Indian Institute of Science in Bengaluru. He did post-doctoral research at Paris Diderot University. Then he was a visiting scientist at the Memorial University of Newfoundland.

He worked as a Professor in Indian Institute of Science and also served as a Visiting Professor at the Max Planck Institute for Biophysical Chemistry.

Then he became the Director General of the Council of Scientific & Industrial Research (CSIR) and Secretary, Department of Scientific and Industrial Research (DSIR), Government of India. He was the Founder Director of Institute of Genomics and Integrative Biology (IGIB), New Delhi and the Chief Mentor of Open Source for Drug Discovery (OSDD) Project.

The J.C Bose Fellowship Award is one among the many honours that he has received.

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What are Sunil Mukhi’s areas of research?

Dr. Sunil Mukhi is an Indian theoretical physicist who has greatly contributed to the string theory and the quantum field theory. We have already dealt with the string theory. The quantum field theory studies the behaviour of subatomic particles in different kinds of force fields.

Dr Mukhi took a Ph.D. in theoretical physics from the State University of New York at Stony Brook in 1981. Then he did postdoctoral studies at the International Centre for Theoretical Physics, in Trieste, Italy. He came back to India and joined the Theoretical Physics Group at the Tata Institute of Fundamental Research, Mumbai in 1993.

He joined as head of the Physics department of the Indian Institute of Science Education and Research, Pune in 2012. He rose to become the Dean after 7 years.

He is a Fellow of the Indian Academy of Sciences, and the Indian National Science Academy. He has received the Shanti Swarup Bhatnagar award for Physical Sciences, 1999, and the J.C. Bose Fellowship, 2008. He was named a Fellow of TWAS, (The World Academy of Sciences) in October 2014.

He is also the editor of the Journal of High Energy Physics since its start.

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What was invented by DF Arago in 1820?

On September 25, 1820, French physicist Francois Arago announced his discovery of an occurrence of electromagnetism. This was just one of Arago’s many contributions as he spent a lifetime for the progress of science.

It isn’t often that we come across a person who contributes significantly to a number of different fields. Such polymaths – individuals whose knowledge encompasses a wide range of subjects – have always been rare. Frenchman Dominique Francois Jean Arago was one such person in this world, as he donned the hat of a physicist. mathematician, astronomer, and politician in an eventful life.

Born in 1786 in Estagel, Roussillon, France, Arago was one of 11 children. Educated at the Municipal College of Perpignan, Arago was drawn towards mathematics from a young age. He was admitted to the Ecole Polytechnique in Paris, where he succeeded French mathematician Gaspard Monge as the chair of Analytic Geometry at the young age of 23.

Love for optics

He made his first major contributions to science in the decade that followed. Working with French engineer Augustin-Jean Fresnel, Arago was able to show that while two rays polarised in a plane can interfere with each other, two beams of light polarised perpendicular to each other cannot interfere with each other. This research led to the discovery of the laws of light polarisation.

In 1820, Arago briefly interrupted his optical work to significantly expand on electromagnetic theories. Having been invited to Geneva to witness the experiments of Danish physicist Hans Christian Oersted linking electricity to magnetism, Arago was instantly converted and developed a huge interest in the subject.

Apart from repeating the Geneva experiments at the Paris Academy, Arago also experimented on his own. He was able to demonstrate that by passing an electric current through a cylindrical spiral of wire, it could be made to behave like a magnet. The temporary magnetisation allowed it to attract iron filings, which then fell off when the current ceased. He announced this occurrence of electromagnetism on September 25, 1820.

Electromagnetic induction

Soon after, Arago discovered the principle of the production of magnetism by rotation of a nonmagnetic conductor. He was able to show that the rotation of a nonmagnetic metallic substance like copper created a magnetic effect as it produced rotation in a magnetic needle suspended over it. It was another decade before English scientist Michael Faraday explained these using his theory of electromagnetic induction in 1831.

Arago served as the director of the Paris Observatory from 1830. As an astronomer, he was among the first to explain the scintillation of stars using interference phenomena. He was also able to provide vital stimulus to young astronomers, including Frenchman Urbain Le Verrier.

“With the point of his pen”

In 1845, Arago suggested to his protege that he investigate the anomalies in the motion of Uranus. These investigations resulted in Le Verriers discovery of Neptune in 1846, and Arago best summed it up when he called Le Verrier the man who “discovered a planet with the point of his pen”. Arago backed Le Verrier in the dispute between Le Verrier and British astronomer John Couch Adams over priority in discovering Neptune and even suggested naming the planet for Le Verrier.

Amidst all his scientific endeavours, Arago also found time to back the ideas of others. Even though French photographer Louis Daguerre was struggling to sell his daguerreotype process, he was able to catch the attention of Arago, who served as the permanent secretary of the French Academy of Sciences.

Advocate for photography

Arago arranged for the first public display of daguerreotypes in January 1839 and used the buzz it created for his lobbying. He was able to get the French Parliament to grant pensions to Daguerre and Isidore Niepce, son of French inventor Nicephore Niepce, so that they could make all the steps of the photographic process public. Arago stated that “France should then nobly give to the whole world this discovery which could contribute so much to the progress of art and science” and the technical details were made public on August 19, 1839 (hence celebrated as World Photography Day).

Optics and the study of light remained close to Arago’s heart and he devised an experiment to prove the wave theory of light. In 1838, he described a test for comparing the velocity of light in air and in water or glass. The elaborate arrangements required for the experiment and his own failing eyesight, however, meant that it wasn’t performed. Shortly before Arago’s death, French physicists Hippolyte Fizeau and Leon Foucault demonstrated the retardation of light in denser media by improving on Arago’s suggested method.

For a man who spent so much of his time pursuing science, he was also able to devote to other causes as a politician. Following the July Revolution of 1830 and up until his death in 1853, Arago was active as a politician, delivering influential speeches regarding educational reform, freedom of press, and the application of scientific thought for progress. After the February Revolution of 1848, he served as the Minister of War and the Navy and used his power to abolish slavery in French colonies. Arago’s influential life highlights the fact that he always possessed the faculty to inspire and stimulate those around him and the public at large, both in the realm of science and in politics.

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Which is Europe’s largest nuclear plant?

The Zaporizhzhia plant in southern Ukraine is Europe’s largest nuclear plant. It was captured by Russia in March, following its invasion of Ukraine in February 2022, raising global fears of a nuclear disaster. Bouts of shelling in the region followed, prompting calls for an urgent inspection of the facility by experts of the International Atomic Energy Agency (IAEA). But what is IAEA and what are its functions? Let’s find out.

The International Atomic Energy Agency, abbreviated as IAEA, is the United Nations’ nuclear watchdog. The centre for nuclear cooperation and safeguards, the IAEA seeks to promote safe, secure, and peaceful use of nuclear technologies contributing to international security.

It was U.S. President Eisenhower’s “Atoms for Peace” address to the U.N. General Assembly (UNGA) in December 1953 that sowed the seeds for the creation of the agency. The IAEA was established in 1957 as an autonomous agency within the U.N family in response to fears arising from the varied uses of nuclear technology.

The IAEA is an autonomous agency with its headquarters in Vienna, Austria. It works with its over 170 member states worldwide to “promote and control the Atom” for peaceful purposes and enable exchange of scientific and technical information between them. Being the international safeguards inspectorate, its mandate includes setting the framework for cooperative efforts to strengthen an international nuclear safety and security regime and verifying whether the member states fulfil their non-proliferation undertakings under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).

Funded by its member states and other donors, the IAEA runs scientific research labs in Austria, Monaco, and Italy. It reports to the UN General Assembly every year, and to the UN Security Council if need be when there are instances of non-compliance with regard to safeguards and security obligations by member states.

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WHAT IS NUCLEAR POWER AND ENERGY?

An atom is the building block of all matter. Nuclear energy is the energy that exists at the core of the atom called the nucleus. Nuclear energy can be accessed through two kinds of atomic reactions nuclear fission and nuclear fusion. In the first reaction, atoms are broken apart whereas in the latter they are forced to fuse together. However, to date, nuclear power plants do not have a safe and reliable way to generate energy through nuclear fusion. Therefore, nuclear reactors use uranium as fuel to produce energy by nuclear fission.

World nuclear power

Nuclear power provides almost 15 percent of the world’s electricity. The first nuclear power plants, which were small demonstration facilities, were built in the 1960s. These prototypes provided “proof-of-concept” and laid the groundwork for the development of the higher-power reactors that followed.

The nuclear power industry went through a period of remarkable growth until about 1990, when the portion of electricity generated by nuclear power reached a high of 17 percent. That percentage remained stable through the 1990s and began to decline slowly around the turn of the 21st century, primarily because of the fact that total electricity generation grew faster than electricity from nuclear power while other sources of energy (particularly coal and natural gas) were able to grow more quickly to meet the rising demand. This trend appears likely to continue well into the 21st century. The Energy Information Administration (EIA), a statistical arm of the U.S. Department of Energy, has projected that world electricity generation between 2005 and 2035 will roughly double (from more than 15,000 terawatt-hours to 35,000 terawatt-hours) and that generation from all energy sources except petroleum will continue to grow.

In 2012 more than 400 nuclear reactors were in operation in 30 countries around the world, and more than 60 were under construction. The United States has the largest nuclear power industry, with more than 100 reactors; it is followed by France, which has more than 50. Of the top 15 electricity-producing countries in the world, all but two, Italy and Australia, utilize nuclear power to generate some of their electricity. The overwhelming majority of nuclear reactor generating capacity is concentrated in North America, Europe, and Asia. The early period of the nuclear power industry was dominated by North America (the United States and Canada), but in the 1980s that lead was overtaken by Europe. The EIA projects that Asia will have the largest nuclear capacity by 2035, mainly because of an ambitious building program in China.

A typical nuclear power plant has a generating capacity of approximately one gigawatt (GW; one billion watts) of electricity. At this capacity, a power plant that operates about 90 percent of the time (the U.S. industry average) will generate about eight terawatt-hours of electricity per year. The predominant types of power reactors are pressurized water reactors (PWRs) and boiling water reactors (BWRs), both of which are categorized as light water reactors (LWRs) because they use ordinary (light) water as a moderator and coolant. LWRs make up more than 80 percent of the world’s nuclear reactors, and more than three-quarters of the LWRs are PWRs.

Issues affecting nuclear power

Countries may have a number of motives for deploying nuclear power plants, including a lack of indigenous energy resources, a desire for energy independence, and a goal to limit greenhouse gas emissions by using a carbon-free source of electricity. The benefits of applying nuclear power to these needs are substantial, but they are tempered by a number of issues that need to be considered, including the safety of nuclear reactors, their cost, the disposal of radioactive waste, and a potential for the nuclear fuel cycle to be diverted to the development of nuclear weapons. All of these concerns are discussed below.

Safety

The safety of nuclear reactors has become paramount since the Fukushima accident of 2011. The lessons learned from that disaster included the need to (1) adopt risk-informed regulation, (2) strengthen management systems so that decisions made in the event of a severe accident are based on safety and not cost or political repercussions, (3) periodically assess new information on risks posed by natural hazards such as earthquakes and associated tsunamis, and (4) take steps to mitigate the possible consequences of a station blackout.

Credit : Britannica 

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HOW DOES AN LED WORK?

LED stands for Light-emitting diode. It is a semiconductor device that emits light when an electric current flows through it. Unlike others lights, LEDS never dim with time and have an extended lifespan that can last a couple of years. They also do not contain poisonous gases like mercury that are commonly used to make the traditional lights. These energy-efficient bulbs are made up of glass and aluminum, which can be recovered by recycling and used to create other products.

The LED is a specialised form of PN junction that uses a compound junction. The semiconductor material used for the junction must be a compound semiconductor. The commonly used semiconductor materials including silicon and germanium are simple elements and junction made from these materials do not emit light. Instead compound semiconductors including gallium arsenide, gallium phosphide and indium phosphide are compound semiconductors and junctions made from these materials do emit light.

These compound semiconductors are classified by the valence bands their constituents occupy. For gallium arsenide, gallium has a valency of three and arsenic a valency of five and this is what is termed a group III-V semiconductor and there are a number of other semiconductors that fit this category. It is also possible to have semiconductors that are formed from group III-V materials.

The light emitting diode emits light when it is forward biased. When a voltage is applied across the junction to make it forward biased, current flows as in the case of any PN junction. Holes from the p-type region and electrons from the n-type region enter the junction and recombine like a normal diode to enable the current to flow. When this occurs energy is released, some of which is in the form of light photons.

It is found that the majority of the light is produced from the area of the junction nearer to the P-type region. As a result the design of the diodes is made such that this area is kept as close to the surface of the device as possible to ensure that the minimum amount of light is absorbed in the structure.

To produce light which can be seen the junction must be optimised and the correct materials must be chosen. Pure gallium arsenide releases energy in the infra read portion of the spectrum. To bring the light emission into the visible red end of the spectrum aluminium is added to the semiconductor to give aluminium gallium arsenide (AlGaAs). Phosphorus can also be added to give red light. For other colours other materials are used. For example gallium phoshide gives green light and aluminium indium gallium phosphide is used for yellow and orange light. Most LEDs are based on gallium semiconductors.

Credit : Electronics notes 

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WHAT IS INFRARED RADIATION?

Infrared radiation or infrared light is a radiant energy that is invisible to the human eyes, but can be felt as heat. It is a type of electromagnetic radiation spectrum with frequencies being produced when atoms absorb and release energy. The two most obvious sources of infrared light are the sun and fire.

Every object in the universe can emit IR radiation at some level and the most well-known sources are fire and the sun.

IR is a kind of electromagnetic radiation wherein frequencies in a continuum get produced as atoms that release and absorb energy.

It can go from the lowest to the highest frequency.

Included in electromagnetic radiation are radio waves, microwaves, infrared radiation, gamma rays, X-rays, visible light, and ultraviolet radiation.

When these kinds of radiation go together, they create the electromagnetic spectrum.

According to NASA, William Herschel, a well-known British astronomer, discovered infrared light in the year 1800.

He had an experiment that could measure how the colors in the visible spectrum have different temperatures.

He had thermometers placed in the light path of every color in the visible spectrum and was able to observe the temperature increase when it went from blue to red.

William also discovered that the measurement of warmer temperature was beyond the visible spectrum’s red end.

Infrared waves happen at frequencies above the microwaves in the electromagnetic spectrum.

They are just below the visible red light, which is why they are called “infrared.”

As per Caltech or the California Institute of Technology, compared to visible light, infrared radiation has longer waves.

The IR frequencies can range from around 300 GHz to approximately 400 THz, with wavelengths estimated to have a range from 1,000 micrometers to 760 nanometers.

However, according to NASA, these values may not be definitive.

Just like the visible spectrum of light that ranges from the longest wavelength of red to the shortest visible light wavelength of violet, infrared radiation comes with a range of wavelengths of its own.

According to NASA, the “far-infrared” waves are longer and closer to the electromagnetic spectrum’s microwave section.

You can feel this as intense heat that is the same as the heat from fire or sunlight.

“Near-infrared” waves that are shorter can be closer to the electromagnetic spectrum’s visible light.

Aside from that, it does not emit detectable heat like what the television’s remote control discharges whenever it changes the channels.

One of the ways you can have heat transferred between two places is IR radiation.

Conduction and convection are the other two.

Everything that has a temperature of more than -268°C or -450°F can emit IR radiation.

As per the University of Tennessee, half of the sun’s total energy is emitted as IR and most of the visible light of a star can get re-emitted and absorbed as IR.

Credit : IRDA

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DOES ELECTROMAGNETIC FORCE IS GREATER THAN THE FORCE OF GRAVITY?

A small horseshoe magnet can pick up a pin from the ground. Does this mean that the electromagnetic force is greater than the force of gravity?The electromagnetic force is millions of times stronger than the force of gravity. Gravity, in fact, is the weakest of the four fundamental forces in the Universe. But whereas the other three forces – electromagnetism and ‘strong’ and weak nuclear forces – act only on the minute particles that make up atoms, gravity acts on a cosmic scale, holding whole galaxies together.

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WHAT IS GRAVITATIONAL SINGULARITY?

A gravitational singularity, spacetime singularity or simply singularity is a condition in which gravity is so intense that spacetime itself breaks down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by “where” or “when”. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete.

Gravitational singularities are mainly considered in the context of general relativity, where density apparently becomes infinite at the center of a black hole, and within astrophysics and cosmology as the earliest state of the universe during the Big Bang/White Hole. Physicists are undecided whether the prediction of singularities means that they actually exist (or existed at the start of the Big Bang), or that current knowledge is insufficient to describe what happens at such extreme densities.

General relativity predicts that any object collapsing beyond a certain point (for stars this is the Schwarzschild radius) would form a black hole, inside which a singularity (covered by an event horizon) would be formed. The Penrose–Hawking singularity theorems define a singularity to have geodesics that cannot be extended in a smooth manner. The termination of such a geodesic is considered to be the singularity.

The initial state of the universe, at the beginning of the Big Bang, is also predicted by modern theories to have been a singularity. In this case, the universe did not collapse into a black hole, because currently-known calculations and density limits for gravitational collapse are usually based upon objects of relatively constant size, such as stars, and do not necessarily apply in the same way to rapidly expanding space such as the Big Bang. Neither general relativity nor quantum mechanics can currently describe the earliest moments of the Big Bang, but in general, quantum mechanics does not permit particles to inhabit a space smaller than their wavelengths.

Credit : Wikipedia 

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WHAT ARE THE FOUR FUNDAMENTAL FORCES OF NATURE?

The Four Fundamental Forces of Nature are Gravitational force, Weak Nuclear force, Electromagnetic force and Strong Nuclear force. The Four Fundamental Forces of Nature are Gravitational force, Weak Nuclear force, Electromagnetic force and Strong Nuclear force.

Gravitational Force

The gravitational force is weak but very long-ranged. Furthermore, it is always attractive. It acts between any two pieces of matter in the Universe since mass is its source.

Weak Nuclear Force

The weak force is responsible for radioactive decay and neutrino interactions. It has a very short range and. As its name indicates, it is very weak. The weak force causes Beta-decay ie. the conversion of a neutron into a proton, an electron and an antineutrino.

Electromagnetic Force

The electromagnetic force causes electric and magnetic effects such as the repulsion between like electrical charges or the interaction of bar magnets. It is long-ranged but much weaker than the strong force. It can be attractive or repulsive and acts only between pieces of matter carrying an electrical charge. Electricity, magnetism, and light are all produced by this force.

Strong Nuclear Force

The strong interaction is very strong but very short-ranged. It is responsible for holding the nuclei of atoms together. It is basically attractive but can be effectively repulsive in some circumstances. The strong force is ‘carried’ by particles called gluons; that is, when two particles interact through the strong force, they do so by exchanging gluons. Thus, the quarks inside of the protons and neutrons are bound together by the exchange of the strong nuclear force.

Note:  While they are close together the quarks experience little force, but as they separate the force between them grows rapidly, pulling them back together. To separate two quarks completely would require far more energy than any possible particle accelerator could provide.

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WHY DOES A PENCIL APPEAR BENT IN WATER?

When a pencil is put in a glass of water, it would appear bent because of refraction of light. Refraction is the bending of light as it passes from one transparent substance into another. Light waves can’t travel as quickly in water as it does in the air. Hence they bend around the pencil, causing the pencil to look bent in the water. Further, the light refraction gives the pencil a slight magnifying effect, which makes the angle appear bigger, causing the pencil to look bent. It all has to do with the fact that light travels more slowly in water than it does in air, and that causes the light to bend when it goes from water to air, or vice versa. How the light bends depends on the shape of the water surface and the angle at which the light hits it.

It is the same “magnifying lens” phenomenon that makes things look fatter when viewed through a glass of water. In that case, the fattening effect is doubled, because the beam of light widens both when it enters the water through a curved surface and when it leaves through the other side.

Credit : Orlando sentinel

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WHY IS THE STRATOSPHERE VITAL?

The stratosphere has a layer of ozone gas, which acts like a thick umbrella covering the layers beneath. By absorbing most of the harmful UV radiation from the Sun, the ozone layer prevents it from reaching the surface of the Earth, thus enabling the survival of life on the planet.

Stratosphere could be aptly called the ‘protection blanket’ of Earth. It extends up to 600 kms from the surface of the earth and it is the second layer of the Earth’s atmosphere, right above troposphere.

Stratosphere houses in it the most important layer called Ozone (O3), which acts as an absorber of the harmful UV radiations of the Sun (of about 90%) and thereby protecting us from diseases like Cancer, skin burn etc.

Its non-turbulance and stable, non-convection character makes it possible for the jets to cruise easily, hence they are flown here.

When Volcanic eruptions occur, the ejected material reaches as high as Stratosphere and it stays there for long period, as it doesn’t allow the circulation, there by leading to stratifying the volcanic particles and cooling down of the Earth surface.

However, such an important layer is being perforated by us through the extensive use of the chloro-fluro-carbons which happen to destroy the ozone molecules.

There is also an idea which the scientists are considering that could result in the slowing down of the Earth’s heating, i.e., by adding the man-made materials to stratosphere. Though the feasibility of this idea is yet to be verified. Thus, is the importance of the Stratosphere layer.

Credit: medium.com

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IS THE ATMOSPHERE BUILT UP IN LAYERS?

Yes, the atmosphere has five layers. The lowest layer, closest to the surface of the Earth, is the troposphere. This is where weather is made, and most of the atmosphere’s gases are concentrated in it. Above it is the Stratosphere. No winds blow in this layer, nor are there any clouds. Beyond it lies the cold mesosphere, with very few gases. It is followed by the thermosphere, the thickest and hottest layer of the atmosphere, and lastly, the exosphere, on the edge of outer space.

Earth’s atmosphere is all around us. Most people take it for granted. Among other things, it shields us from radiation and prevents our precious water from evaporating into space. It keeps the planet warm and provides us with oxygen to breathe. In fact, the atmosphere makes Earth the livable, lovable home sweet home that it is.

The atmosphere extends from Earth’s surface to more than 10,000 kilometers (6,200 miles) above the planet. Those 10,000 kilometers are divided into five distinct layers. From the bottom layer to the top, the air in each has the same composition. But the higher up you go, the further apart those air molecules are.

Troposphere: Earth’s surface to between 8 and 14 kilometers (5 and 9 miles)

This lowest layer of the atmosphere starts at the ground and extends 14 kilometers (9 miles) up at the equator. That’s where it’s thickest. It’s thinnest above the poles, just 8 kilometers (5 miles) or so. The troposphere holds nearly all of Earth’s water vapor. It’s where most clouds ride the winds and where weather occurs. Water vapor and air constantly circulate in turbulent convection currents. Not surprisingly, the troposphere also is by far the densest layer. It contains as much as 80 percent of the mass of the whole atmosphere. The further up you go in this layer, the colder it gets.

Stratosphere: 14 to 64 km (9 to about 31 miles)

Unlike the troposphere, temperatures in this layer increase with elevation. The stratosphere is very dry, so clouds rarely form here. It also contains most of the atmosphere’s ozone, triplet molecules made from three oxygen atoms. At this elevation, ozone protects life on Earth from the sun’s harmful ultraviolet radiation. It’s a very stable layer, with little circulation. For that reason, commercial airlines tend to fly in the lower stratosphere to keep flights smooth. This lack of vertical movement also explains why stuff that gets into in the stratosphere tends to stay there for a long time. That “stuff” might include aerosol particles shot skyward by volcanic eruptions, and even smoke from wildfires. This layer also has accumulated pollutants, such as chlorofluorocarbons. Better known as CFCs, these chemicals can destroy the protective ozone layer, thinning it greatly. By the top of the stratosphere, called the stratopause, air is only a thousandth as dense as at Earth’s surface.

Mesosphere: 64 to 85 km (31 to 53 miles)

Scientists don’t know quite as much about this layer. It’s just harder to study. Airplanes and research balloons don’t operate this high and satellites orbit higher up. We do know that the mesosphere is where most meteors harmlessly burn up as they hurtle towards Earth.

The mesopause is also known as the Karman line. It’s named for the Hungarian-born physicist Theodore von Kármán. He was looking to determine the lower edge of what might constitute outer space. He set it at about 80 kilometers (50 miles) up.

The ionosphere is a zone of charged particles that extends from the upper stratosphere or lower mesosphere all the way to the exosphere. The ionosphere is able to reflect radio waves; this allows radio communications.

Thermosphere: 85 to 600 km (53 to 372 miles)

The next layer up is the thermosphere. It soaks up x-rays and ultraviolet energy from the sun, protecting those of us on the ground from these harmful rays. The ups and downs of that solar energy also make the thermosphere vary wildly in temperature. It can go from really cold to as hot as about 1,980 ºC (3,600 ºF) near the top. The sun’s varying energy output also causes the thickness of this layer to expand as it heats and to contract as it cools. With all the charged particles, the thermosphere is also home to those beautiful celestial light shows known as auroras. This layer’s top boundary is called the thermopause.

Exosphere: 600 to 10,000 km (372 to 6,200 miles)

The uppermost layer of Earth’s atmosphere is called the exosphere. Its lower boundary is known as the exobase. The exosphere has no firmly defined top. Instead, it just fades further out into space. Air molecules in this part of our atmosphere are so far apart that they rarely even collide with each other. Earth’s gravity still has a little pull here, but just enough to keep most of the sparse air molecules from drifting away. Still, some of those air molecules — tiny bits of our atmosphere — do float away, lost to Earth forever.

Credit: Science news for students

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WHAT IS THE IONOSPHERE?

It is another layer, overlapping the mesosphere, thermosphere and exosphere, where radio waves are reflected.

A dense layer of molecules and electrically charged particles, called the ionosphere, hangs in the Earth’s upper atmosphere starting at about 35 miles (60 kilometers) above the planet’s surface and stretching out beyond 620 miles (1,000 km). Solar radiation coming from above buffets particles suspended in the atmospheric layer. Radio signals from below bounce off the ionosphere back to instruments on the ground. Where the ionosphere overlaps with magnetic fields, the sky erupts in brilliant light displays that are incredible to behold.

Several distinct layers make up Earth’s atmosphere, including the mesosphere, which starts 31 miles (50 km) up, and the thermosphere, which starts at 53 miles (85 km) up. The ionosphere consists of three sections within the mesosphere and thermosphere, labeled the D, E and F layers, according to the UCAR Center for Science Education.

Extreme ultraviolet radiation and X-rays from the sun bombard these upper regions of the atmosphere, striking the atoms and molecules held within those layers. The powerful radiation dislodges negatively charged electrons from the particles, altering those particles’ electrical charge. The resulting cloud of free electrons and charged particles, called ions, led to the name “ionosphere.” The ionized gas, or plasma, mixes with the denser, neutral atmosphere.

Credit: Live Science

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Freakish wonders of the universe

The universe is full of deep mysteries and even the fraction of what we know is too fascinating for words. This month let’s take a look at some of the amazing yet scary inhabitants out there.

I’m coming to visit you

Black holes form when huge stars collapse and grow, taking up other objects around them. Think of them as giant invisible blenders that can tear apart planets even thousands of miles away. There aren’t black holes anywhere close to our solar system, but did you know that they can actually travel through space? And scarier still, rapidly-moving black holes cannot be detected! Scientists have assured us that space is a big place and black holes are quite rare – so sit back and relax!

A big show off!

Ever heard of gamma ray bursts? Well, they are considered as the brightest electromagnetic events to occur in the universe, so much so, that they can be seen billions of miles away! Are you also wondering how powerful they are? Apparently they emit as much energy in a few seconds that our sun can in 10 billion years! We’re glad that, like black holes, they are rare and far, far away from us.

Lone travellers

We imagine planets going around a star, endlessly orbiting it as long as they live. It turns out that not all planets exist this way. Astronomers have discovered a few Jupiter-sized planets drifting alone, without a place to call home or a star as a boss. They are thought to have been ejected out of their star system due to some massive explosion event. As long as they are not on a trajectory towards Earth, it’s dreamy fun to think about these lonely nomadic travellers.

What a blast!

Earth is like a magnet but its magnetic field is quite weak; an MRI machine can produce a magnetic field thousand times stronger. Since we can put our head in through the MRI machine, we can obviously put up with that magnetic field. But imagine a magnetic field that is a trillion times stronger than that of Earth. That’s the kind of power that a magnetar possesses! Come within 1000 kilometres of a magnetar and the very molecules that make you up can dissolve! Here’s a fun fact to freak you out in 2004, a magnetar located halfway across the Milky Way (500 quadrillion kilometres away) quaked and its effect was felt on the Earth’s upper atmosphere!

Mission Impossible

What if you stepped too close to a black hole but not quite? That’s exactly what hypervelocity stars did! They bolted away from the black hole at superfast speed. Hypervelocity stars were originally binary stars, of which one was captured and gobbled up by the black hole at the centre of our galaxy while the other lucky star was sent rocketing off at a very high speed, obviously very, very glad to escape.

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HOW MANY HOURS ARE THERE IN A DAY?

Our system of telling time is based on the premise that every day is exactly 24 hours long — quite precisely, with no exceptions. This concept is fully ingrained into our culture, a core principle of our modern technological society. At the same time, we are taught in school that a day corresponds to one complete rotation of the Earth on its axis. Unfortunately, these two concepts don’t quite match up — and the mismatch is more than just a few milliseconds. In fact, the mismatch amounts to several minutes every day. Furthermore, because our traditional concept of a “day” is actually defined by the cycle of sunlight and darkness — and not by one rotation of the Earth — the length of a real day is not consistent, but varies somewhat during the year. We only pretend that all days are the same length — by averaging the length of all the days in the year, and then defining this average as a “standard day” of exactly 24 hours.

This is not a bad thing. In fact, it has been quite helpful to define our system of time in this manner. But once you understand why this system does not quite match up with the real world, then you can begin to make sense of several interesting phenomena. For example, you would think that the earliest sunset and the latest sunrise would both occur on the shortest day of the year, which is the first day of winter. But this is not the case at all.

If our definition of a day was truly based on one complete rotation of the Earth on its axis — a 360 degree spin — then a day would be 23 hours, 56 minutes, and 4 seconds. This is nearly 4 minutes shorter than our 24-hour standard day. However, our concept of a “day” has long been based on the natural cycle of sunlight — a period of daylight followed by a period without daylight. The mismatch of nearly 4 minutes is because the Earth must rotate more than 360 degrees between one dawn and the next. As you know, the Earth experiences two simultaneous motions — it not only spins on its axis, but it also travels in orbit around the sun. In a period of one day, the Earth travels about 1/365 of the way around the sun (because it takes about 365 days to go all the way around, which is how we define a year). This daily progress in the Earth’s orbit is almost exactly a degree (defined as 1/360 of a circle). Therefore the Earth has to spin an extra degree in order to line up with the sun again each day. The result is that one complete cycle of sunlight and darkness — one day — represents a rotation of about 361 degrees, not 360 degrees. Although a year consists of 365 and a quarter days, the Earth actually spins 366 and a quarter times during a year. From the standpoint of sunrises and sunsets, one complete spin is negated each year by the journey around the sun.

Credit: medium.com

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WHERE IS THE ANTARCTIC CIRCLE?

The Antarctic Circle is a parallel of latitude on the Earth at approximately 66.5 degrees south of the equator. On the day of the southern summer solstice (around December 22 each year), an observer on the Antarctic Circle will see the Sun above the horizon for a full 24 hours.

Observers further south than the Antarctic Circle will see the Sun remain above the horizon for many days, and at the South Pole, there is a six-month ‘day’ that starts on the autumnal equinox changing to a six-month ‘night’ on the vernal equinox.

The 66.5 degree angle comes from the tilt of the Earth’s rotation axis (23.5°), such that 90° – 23.5° = 66.

Credit: Cosmos

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WHERE IS THE ARCTIC CIRCLE?

The Arctic Circle is a line of latitude that circles the Earth at approximately 66° 33′ 47.2″ north of the Equator. How was that strange number determined? The position of the Arctic Circle is at the latitude above which the sun does not set on the summer solstice and does not rise on the winter solstice.

This is what causes the Arctic to have a very long continuous night each year and a very long continuous day. The length of these long continuous days and nights are six months each at the North Pole. Their length decreases with distance from the North Pole.

The latitude of the Arctic Circle is slowly drifting northward at a speed of about 15 meters per year. On July 2, 2018 it was at approximately 66° 33′ 47.2″ north of the Equator. This drift has nothing to do with climate change. Instead, the drift occurs because the Earth wobbles on its axis of rotation in a 40,000 year cycle in response to the gravitational attraction of the moon.

To most of the general public, using the Arctic Circle as the defining southern boundary for “the Arctic” is easy and makes total sense. However, some researchers believe that there are better ways to draw a map of the Arctic.

Credit: geology.com

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WHAT IS THE EQUATOR?

The equator is the circle that goes round the centre of Earth. It is perpendicular to the axis and divides the planet into two equal hemispheres (or half-spheres), the Northern and the Southern.

The Earth’s Equator is the imaginary line that runs around the centre of the globe at 0 degrees latitude, at equal distance between the North and South Poles. Like the other lines of latitude, it’s based on the Earth’s axis of rotation and its orbit around the sun. It is the longest of Earth’s five circles of latitude, the others being the polar circles, and tropical circles. This is because of how the Earth bulges around its centre.

The Equator is just under 25,000 miles long, wrapping around the entire Earth. The Equator divides the Earth into northern and southern hemispheres, with both experiencing different amounts of daylight at different times. This, weather, climate and the seasons we experience are a result of the Earth’s tilt on its axis and its orbit around the sun. The northern and southern hemispheres are either turned toward or away from the sun depending on the Earth’s position whilst it’s orbiting the sun.

When the Sun is directly above the Earth’s Equator, sunlight shines perpendicular to the Earth’s axis, and all latitudes have a 12-hour day and 12-hour night. The Sun passes directly over the equator twice a year, on the March and September equinoxes.

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WHY ARE LATITUDE AND LONGITUDE IMPORTANT?

Two points on Earth can lie at the same latitude but still be far away from each other. Similarly, two distant points may lie on the same longitude. But only one point lies on a particular combination of latitude and longitude. So latitudes and longitudes are necessary for locating an exact point on Earth.

The importance of longitude and latitude are:

  • Latitudes help in identifying and locating major heat zones of the earth.
  • Latitude measures the distance between the north to south from the equator.
  • Latitude helps in understanding the pattern of wind circulation on the global surface.
  • Longitude measures the distance between the west to earth from the prime meridian.
  • Both longitude and latitude help us measure both the location and time using a single standard.
  • The lines of longitude and latitude help us in measuring the distance from the Earth’s Equator
  • Latitudes help us to find out the distance of any place from the Equator, which is base on its degree of latitude.
  • Longitude and latitude help us to find the location of any place on earth. These coordinates are what the Global Position System or GPS

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What is nebula?

A nebula is a formation in space which is constituted mostly of helium, dust, and other gases in various concentrations. The shape and size of a nebula varies, and as such there can be various types of formations having different sizes. Very often, they are huge in size, and their diameters can be a number of light years across. It is derived from Latin, and as such means a cloud. Nebulae exist in the space between the stars—also known as interstellar space. The closest known nebula to Earth is called the Helix Nebula. It is the remnant of a dying star—possibly one like the Sun. It is approximately 700 light-years away from Earth.

It is not clear how exactly a nebula is formed, but it is believed that they are formed by the collapsing of interstellar medium, which then come together because of the gravitational pull of the particles. Nebula is an important object for observation by researchers, who derive significant information about the formation process of stars and planets. A nebula is capable of exerting a gravitational pull, and the force is derived from the particles which come together to form the nebula. With more particles coming together, not only does the nebula increase in proportion, but its gravitational pull also gathers more power and intensity. A nebula is also believed to be one of the primary stages in the formation of stars. Scientists are of the opinion that a nebula can be used to create a trajectory of stellar evolution. There are various nebulae that are in existence at present, though numerous others may exist in the far-flung corners of space that remain to be observed. Some of the most popular ones are Pelican, Crab, Eagle, and Ring Nebula, with Ring being among the most observed ones on the planet.

Credit : Economic Times

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WHAT MAKES THE SEASONS?

Earth is always tilted the same direction as it orbits the Sun. So when Earth is on one side of the Sun, the northern hemisphere is tilted closer towards the Sun, making it warmer. At the same time, the southern hemisphere is tilted away from the Sun, and is, therefore, colder. When Earth reaches the other side of the Sun, it is the opposite, so it’s winter in the northern hemisphere and summer in the southern.

Seasons happen at different times in different parts of the world. The tilt of the Earth doesn’t change as it rotates around the Sun. But the part of the planet that gets the most direct sunlight does change.

The Northern Hemisphere is tilted away from the Sun from September to March. That means the northern half of the planet doesn’t get as much light and heat from the Sun. This causes autumn and winter. During the same months, the Southern Hemisphere is tilted towards the Sun. That means the southern half of the planet gets spring and summer.

From March to September, the Northern Hemisphere is tilted towards the Sun. So that’s when the northern half of the Earth experiences spring and summer. During the same months, the Southern Hemisphere experiences autumn and winter.
Other planets also have seasons. But the length and intensity of each season varies from planet to planet.

  • On Earth, seasons last between 90 and 93 days.
  • On Venus, seasons last between 55 and 58 days.
  • On Mars, seasons change about once every six months. Summer lasts 199 days and winter lasts 146 days.
  • On Saturn, seasons last about seven years.
  • And if you lived on Neptune, you would have to wait more than 40 years for the seasons to change!

Credit: Let’s talk Science

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WHAT IS THE PRIME MERIDIAN?

This is an imaginary line of 0° longitude that is perpendicular to the equator, and parallel to the axis. It passes through Greenwich in the UK, and divides Earth into eastern and western hemispheres. As it crosses the poles to the opposite side of the globe, the line becomes 180° longitude and is also known as the International Date Line.

The prime meridian is arbitrary, meaning it could be chosen to be anywhere. Any line of longitude (a meridian) can serve as the 0 longitude line. However, there is an international agreement that the meridian that runs through Greenwich, England, is considered the official prime meridian.

Governments did not always agree that the Greenwich meridian was the prime meridian, making navigation over long distances very difficult. Different countries published maps and charts with longitude based on the meridian passing through their capital city. France would publish maps with 0 longitude running through Paris. Cartographers in China would publish maps with 0 longitude running through Beijing. Even different parts of the same country published materials based on local meridians.

Finally, at an international convention called by U.S. President Chester Arthur in 1884, representatives from 25 countries agreed to pick a single, standard meridian. They chose the meridian passing through the Royal Observatory in Greenwich, England. The Greenwich Meridian became the international standard for the prime meridian.

Credit: National geographic

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WHAT ARE TIME ZONES?

As Earth spins, different parts of its surface turn towards the Sun at different times – the Sun is always rising in one place and setting in another. So, the time of day varies around the world. When it’s dawn where you live, it’s sunset on the other side of the world. To make it easier to set clocks, the world is split into 24 time zones, one for each hour of the day. As you go east around the world, you put clocks forward by one hour for each zone – until you reach an imaginary line called the International Date Line. If you go further on across the Date Line, you carry on adding hours, but put the calendar back by a day.

A time zone is a region on Earth that uses a uniform time. They are often based on the boundaries of countries or lines of longitude. Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory located in Greenwich, London, considered to be located at a longitude of zero degrees. Although GMT and Coordinated Universal Time (UTC) essentially reflect the same time, GMT is a time zone, while UTC is a time standard that is used as a basis for civil time and time zones worldwide. Although GMT used to be a time standard, it is now mainly used as the time zone for certain countries in Africa and Western Europe. UTC, which is based on highly precise atomic clocks and the Earth’s rotation, is the new standard of today.

UTC is not dependent on daylight saving time (DST), though some countries switch between time zones during their DST period, such as the United Kingdom using British Summer Time in the summer months.

Most time zones that are on land are offset from UTC. UTC breaks time into days, hours, minutes, and seconds, where days are usually defined in terms of the Gregorian calendar. Generally, time zones are defined as + or – an integer number of hours in relation to UTC; for example, UTC-05:00, UTC+08:00, and so on. UTC offset can range from UTC-12:00 to UTC+14:00. Most commonly, UTC is offset by an hour, but in some cases, the offset can be a half-hour or quarter-hour, such as in the case of UTC+06:30 and UTC+12:45

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HOW THICK IS EARTH’S CRUST?

Earth’s Crust

The crust is what we live on and is by far the thinnest of the layers of earth. The thickness varies depending on where you are on earth, with oceanic crust being 5-10 km and continental mountain ranges being up to 30-45 km thick. Thin oceanic crust is denser than the thicker continental crust and therefore ‘floats’ lower in the mantle as compared to continental crust. You will find some of the thinnest oceanic crust along mid ocean ridges where new crust is actively being formed. In comparison, when two continents collide as in the case of the India Plate and Eurasia Plate, you get some of the thickest sections of crust as it is crumpled together.

The temperatures within Earth’s crust will vary from air temperatures at the surface to approximately 870 degrees Celsius in deeper sections. At this temperature, you begin to melt rock and form the below-lying mantle. Geologists subdivide Earth’s crust into different plates that move about in relation to one another.

Given that Earth’s surface is mostly constant in area, you cannot make crust without destroying a comparable amount of crust. With convection of the underlying mantle, we see insertion of mantle magma along mid ocean ridges, constantly forming new oceanic crust. However, to make room for this, oceanic crust must subduct (sink below) continental crust.  Geologists have studied extensively the history of this plate movement, but we are sorely lacking in determining why and how these plates move the way they do.

Earth’s crust “floats” on top of the soft plastic-like mantle below. In some instances mantle clearly drives changes in the crust, as in the Hawaiian Islands. However, there is ongoing debate whether oceanic crust subduction and mid ocean ridge spreading is driven by a push or pull mechanism.

In very broad terms, oceanic crust is made up of basalt and continental crust is made up of rocks similar to granite. Below the crust is a solid relatively cooler portion of the upper mantle that is combined with the crust to make the  lithosphere layer. The lithosphere is physically distinct from the below-lying layers due to its cool temperatures and typically extends 70-100 km in depth.

Below the lithosphere is the asthenosphere layer, a much hotter and malleable portion of the upper mantle. The asthenosphere begins at the bottom of the lithosphere and extends approximately 700 km into the Earth. The asthenosphere acts as the lubricating layer below the lithosphere that allows the lithosphere to move over the Earth’s surface.

Credit: Forbes

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HOW DOES EARTH GET ITS MAGNETIC FIELD?

The Earth’s outer core is in a state of turbulent convection as the result of radioactive heating and chemical differentiation. This sets up a process that is a bit like a naturally occurring electrical generator, where the convective kinetic energy is converted to electrical and magnetic energy. Basically, the motion of the electrically conducting iron in the presence of the Earth’s magnetic field induces electric currents. Those electric currents generate their own magnetic field, and as the result of this internal feedback, the process is self-sustaining so long as there is an energy source sufficient to maintain convection.

Unlike Mercury, Venus, and Mars, Earth is surrounded by an immense magnetic field called the magnetosphere. Generated by powerful, dynamic forces at the center of our world, our magnetosphere shields us from erosion of our atmosphere by the solar wind (charged particles our Sun continually spews at us), erosion and particle radiation from coronal mass ejections (massive clouds of energetic and magnetized solar plasma and radiation), and cosmic rays from deep space. Our magnetosphere plays the role of gatekeeper, repelling this unwanted energy that’s harmful to life on Earth, trapping most of it a safe distance from Earth’s surface in twin doughnut-shaped zones called the Van Allen Belts.

But Earth’s magnetosphere isn’t a perfect defense. Solar wind variations can disturb it, leading to “space weather” — geomagnetic storms that can penetrate our atmosphere, threatening spacecraft and astronauts, disrupting navigation systems and wreaking havoc on power grids. On the positive side, these storms also produce Earth’s spectacular aurora. The solar wind creates temporary cracks in the shield, allowing some energy to penetrate down to Earth’s surface daily. Since these intrusions are brief, however, they don’t cause significant issues.

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WHY IS THE CORE OF EARTH MADE OF IRON?

Because as Earth cooled, dense metal like iron sank to the centre, while lighter rock-forming materials floated to the top.

At the center of Earth is a solid iron inner core. The hot dense core has a radius of about 759 miles (1,221 kilometers) and a pressure of about 3.6 million atmospheres (atm).

Temperatures in the inner core are about as hot as the surface of the sun (about 9,392 degrees F or 5,200 degrees C) — more than hot enough to melt iron — but the immense pressure from the rest of the planet keeps the inner core solid, according to National Geographic.

The primary contributors to the inner core’s heat are the decay of radioactive elements such as uranium, thorium and potassium in Earth’s crust and mantle, residual heat from planetary formation, and heat emitted by the solidification of the outer core.

Earth’s inner core rotates in the same direction as the surface of the planet but rotates ever so slightly faster, completing one extra rotation every 1,000 years or so.

Credit: space.com

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WHAT HAPPENS WHEN PLATES COLLIDE?

Plates move at an average of between four and seven centimetres in a year. If plates collide along a deep trench beneath an ocean, one plate is pulled beneath another and melts and is recycled. On land, when continents collide, their edges are pushed up into new mountain ranges.

When two tectonic plates collide, they form a convergent plate boundary.

  • A convergent plate boundary such as the one between the Indian Plate and the Eurasian Plate forms towering mountain ranges, like the Himalayas, as Earth’s crust is crumpled and pushed upward.
  • In some cases, however, a convergent plate boundary can result in one tectonic plate diving underneath another. This process is called subduction. It involves an older, denser tectonic plate being forced deep into the planet underneath a younger, less-dense tectonic plate. When this process occurs in the ocean, a trench can be formed.
  • When subduction occurs, a chain of volcanoes often develops near the convergent plate boundary.

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WHAT IS EARTH MADE OF?

The structure of Earth can be divided into three parts: the crust, the mantle and the core. Made up from mainly oxygen and silicon, the crust is the outermost layer. It is the familiar landscape on which we live: rocks, soil and seabed. Beneath the crust is the mantle, a layer almost 3000 km deep. It is made of metal silicates, sulphides and oxides. This layer is so hot that the rock often flows like sticky road tar – only very, very slowly. Below the mantle is a core of metal, mostly iron, sulphur and nickel. The outer portion of the core is so very hot that the metal is always molten. The Earth’s magnetic field is created here. Earth’s inner core is even hotter – estimated to be around 6000 °C – but the metal is solid because pressure within the inner core is extreme, so the metal cannot melt.

1: The Core

The composition of the Earth begins with the inner parts of the planet. The Earth’s core is the densest part of the planet. It is made up of iron and nickel, and the core is so hot that is heats the rest of the planet around it. The core has chosen how the planet will be heated, and the core of the planet determines the equilibrium of the planet itself.

2: The Magma

The magma underneath the Earth’s surface spins around the world as it keeps the crust warm. The warmth of the magma can be felt in certain parts of the world where the ground is very close to the magma. The magma can be found rising out of the surface of the Earth at volcanoes and underwater cracks in the crust. The magma is the lifeblood of the Earth even though it is quite a scary thing to encounter today.

3: The Crust

The crust of the Earth is the ground that everyone walks on today. The crust is much thinner than the other components of the Earth, but it manages to support all the life on the planet. The Earth’s surface is covered with the crust completely, but much of the Earth’s surface is covered in water. Citizens of the Earth may never explore the floor of the sea, but that area is still a part of the Earth’s crust.

4: Magnetism

The magnetism of the Earth that helps it stay attached to the sun in orbit comes directly from the core. The core’s construction keeps the magnetism of the Earth going in ways that scientists do not understand completely. The magnetism created by the core also helps the Earth create a gravitational field that keeps everyone on the planet.

Credit: AES

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HOW DO WE KNOW WHAT EARTH’S INSIDE LOOK LIKE?

Scientists have worked this out from the vibrations from earthquakes and underground explosions. This data is pictured with lines on 3D maps to help scientists understand the structure of Earth’s core.

Core, mantle, and crust are divisions based on composition. The crust makes up less than 1 percent of Earth by mass, consisting of oceanic crust and continental crust is often more felsic rock. The mantle is hot and represents about 68 percent of Earth’s mass. Finally, the core is mostly iron metal. The core makes up about 31% of the Earth.

CRUST AND LITHOSPHERE

Earth’s outer surface is its crust; a cold, thin, brittle outer shell made of rock. The crust is very thin, relative to the radius of the planet. There are two very different types of crust, each with its own distinctive physical and chemical properties.Oceanic crust is composed of magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro. Sediments, primarily muds and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore where it comes off the continents in rivers and on wind currents.

MANTLE
The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. Scientists know that the mantle is made of rock based on evidence from seismic waves, heat flow, and meteorites. The properties fit the ultramafic rock peridotite, which is made of the iron- and magnesium-rich silicate minerals. Peridotite is rarely found at Earth’s surface.Scientists know that the mantle is extremely hot because of the heat flowing outward from it and because of its physical properties. Heat flows in two different ways within the Earth: conduction and convection. Conduction is defined as the heat transfer that occurs through rapid collisions of atoms, which can only happen if the material is solid. Heat flows from warmer to cooler places until all are the same temperature. The mantle is hot mostly because of heat conducted from the core. Convection is the process of a material that can move and flow may develop convection currents.

CORE
At the planet’s center lies a dense metallic core. Scientists know that the core is metal for a few reasons. The density of Earth’s surface layers is much less than the overall density of the planet, as calculated from the planet’s rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85 percent iron metal with nickel metal making up much of the remaining 15 percent. Also, metallic meteorites are thought to be representative of the core.If Earth’s core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because S-waves stop at the inner core. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core.

Credit: Lumen Learning

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Does your shadow follow you?

A girl walking in the midday sun and could see her small shadow following her. There was a plane flying high overhead but it threw no shadow on the ground. Why?

If an object is placed between a source of light and a screen, a shadow falls on the screen. If the object is smaller than the source of light then the shadow will have a small dark centre called umbra and a larger and lighter shadow surrounding it called the penumbra.

The further you move the object from the screen and towards the source of light, the smaller the umbra. If you take it very far from the screen, the umbra disappears.

The plane high in the sky is the object between the source of light (sun) and the screen (ground). It’s too far away from the screen so there’s no umbra and the penumbra is so faint that it cannot be seen.

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“Give me a place to stand on and I will move the Earth.” said Archimedes in 240 BC. What did he mean?

At least in principle any load can be moved by a lever. A lever is a rigid uniform rod resting on a fixed point called fulcrum at which point it can rotate freely. The length of the lever from this fulcrum to the load is load arm and the length from fulcrum to the point where effort is applied is the effort arm. The lever is balanced when Effort x effort arm Load x load arm. If the effort arm is 100m and load arm 1m, the effort needed to lift 1000 kg will be just 10 kg. So keeping the effort arm proportionally long one can in priciple lift any load and that is what Archimedes was trying to say by this boastful statement.

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Why is it difficult to cook rice or dal when you’re in a place that is at a higher altitude?

The lower the atmospheric pressure, the lower the boiling point of water. At the top of Mount Everest where the atmospheric pressure is less than one-third of what it is at sea level, water boils at around 70 degrees Celsius, whereas in a place like Mumbai, water boils at 100 degrees C

Rice and dal require this higher temperature to get cooked. So though the water may boil at the top of Everest, it will not be hot enough for the rice or dal to cook in it.

The problem can be overcome by using a pressure cooker. In a pressure cooker, due to the high pressure created inside it, water boils at much higher temperatures than normal and so food gets cooked faster.

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When did Surveyor 3 land on the Moon?

Launched on April 17, 1967, Surveyor 3 was the third engineering flight of the Surveyor series and the second in the series to achieve a soft landing on the moon. It was based on Surveyor 3’s surface sampling tests that it was concluded that the lunar surface could hold the weight of an Apollo lunar module

The Apollo 11 mission will remain in the collective consciousness of human beings forever. This is because it was the first time we humans managed to set foot on our natural satellite, the moon.

It is important to remember that this was made possible due to a number of missions that preceded this one. Among these was the Surveyor 3 spacecraft which proved beyond doubt that an Apollo lunar module could indeed safely land on the moon’s surface.

The third engineering flight of the Surveyor series, this spacecraft was the first to carry a surface-sampling instrument that could reach up to 1.5 m from the lander and dig up to 18 cm. Unlike its predecessors, Surveyor 3 began its mission from a parking orbit around Earth on April 17, 1967.

Bouncing to a stop

While it became the second in the series after Surveyor 1 to achieve a soft landing on the moon three days later on April 20, it was far from smooth. As highly reflective rocks confused the landers descent radar, the main engine did not cut off at the correct moment during the descent to the lunar surface.

This meant that Surveyor 3 bounced off the moon, not once but twice-first to a height of 10 m and then again to a height of 3 m. It was third time lucky for Surveyor 3 as it landed softly in the southeastern region of Oceanus  Procellarum.

With its worst behind it. Surveyor 3 set out to do what it was sent to do. Within an hour after landing, the spacecraft began transmitting the first of over 6,000 TV pictures of the surrounding areas.

Similar to wet sand

The most important phase of the mission included deployment of the surface sampler for digging trenches, manipulating lunar material, and making bearing tests. Based on commands from Earth, the probe was able to dig four trenches, performing four bearing tests and 13 impact tests.

The results from these experiments were the most important aspect of this mission. The scientists were able to conclude that lunar soil’s consistency was similar to that of wet sand and that it would be solid enough to bear an Apollo lunar module when it landed.

The start of May saw the first lunar nightfall following the arrival of Surveyor 3. The spacecraft’s solar panels stopped producing electricity and its last contact with Earth was on May 4. While Surveyor 1 could be reactivated twice after lunar nights, Surveyor 3 could not be reactivated when it was attempted 336 hours later during the next lunar dawn.

Tryst with Apollo 12

That, however, wasn’t the last of what we heard about Surveyor 3. Four months after the huge success of Apollo 11, NASA launched Apollo 12 in November 1969. The lunar module of Apollo 12 showcased pinpoint landing capacity as the precise lunar touchdown allowed the astronauts to land within walking distance of the Surveyor 3 spacecraft. During their second extra vehicular activity on November 19, astronauts Charles Conrad, Jr. and Alan L. Bean walked over to the inactive Surveyor 3 lander and recovered parts, including the camera system and the soil scoop.

Just like moon rocks, these were returned to Earth for studying, as they offered scientists a unique chance to analyse equipment that had been subjected to long-term exposure on the moon’s surface. The studies of the parts showed that while Surveyor 3 had changed colour due to lunar dust adhesion and exposure to the sun, the TV camera and other hardware showed no signs of failure.

While NASA placed some of the Surveyor 3 parts into storage along with moon rocks and soil samples, the remaining parts found home elsewhere. Even though NASA treats them as lunar samples and not artefacts, they are greatly valued when gifted or loaned out, both to museums and individuals.

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Who was Marie Curie?

Marie Curie (November 7, 1867-July 4, 1934) was a French Polish physicist and chemist, famous for her pioneering research on radioactivity and the discovery of polonium and radium.  She was the first woman to win a Nobel Prize, the only woman to win in two fields, and the only person to win in multiple sciences. She was also the first female professor at the University of Paris (La Sorbonne), and in 1995 became the first woman to be entombed on her own merits in the Pantheon in Paris]

In 1867, Maria Sklodowska was born in Warsaw, Poland. She was a bright and curious child who did well in school. At the time, the University of Warsaw refused students who were women. But that didn’t stop young Maria! Instead, she learned in secret. She went to informal classes held in ever-changing locations, called the “Floating University.”

In 1891, the woman the world would come to know as Marie Curie made her way to Paris. There, she enrolled at the Sorbonne, a university that didn’t discriminate. Over the next few years, she completed advanced degrees in physics and mathematics. She also met French physicist Pierre Curie. The two married in 1895.

Marie and Pierre worked closely over the next decade. Marie’s biggest discoveries came from studying uranium rays. She believed these rays came from the element’s atomic structure. Curie created the term “radioactivity” to name the phenomena she had observed. Her findings led to the field of atomic physics.

Together, the Curies studied the mineral pitchblende. Through their experiments, they discovered a new radioactive element. Marie named it polonium in honor of her native Poland. The two later also discovered the element radium.

In 1903, Marie and Pierre Curie were jointly awarded the Nobel Prize in physics. Marie was the first woman to receive a Nobel Prize. That same year, she also became the first woman to earn a Ph.D. from a French university. After Pierre’s death in 1906, Marie took over his teaching job at the Sorbonne. She was the first female professor at the institution.

In 1911, Curie became the first person—of any gender—to win a second Nobel Prize. This time, she was recognized for her work in the field of chemistry. Curie’s scientific reputation was known around the world. In fact, she was invited to attend the Solvay Congress in Physics. There, she joined other famous scientists of the day, including Albert Einstein.

After World War I began in 1914, Marie used her scientific knowledge to support France’s efforts in the war. She helped to develop the use of portable X-ray machines in the field. In fact, the medical vehicles that carried these machines became known as “Little Curies.”

Marie Curie never knew the toll her work would take on her health. She died in France in 1934 from advanced leukemia related to prolonged exposure to radiation. Today, Curie’s notebooks are still too radioactive to be safely handled. They are stored in lead-lined boxes in France.

Marie Curie left a great legacy of accomplishment and scientific curiosity. Her daughter, Irène Joliot-Curie, followed in her footsteps. Joliot-Curie received the Nobel Prize in chemistry in 1935, one year after her mother’s death.

In 1995, Marie and Pierre Curie’s remains were placed in the Panthéon in Paris. This is known as the final resting place of France’s most distinguished citizens. Marie Curie was the first woman to be interred there on her own merit.

Credit : Wonder Opolis

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