Chandrasekhar Venkata Raman

                        Chandrasekhar Venkata Raman

The Great Indian physicist Chandrasekhar Venkata Raman, popularly known as C.V Raman, was born on 7th November, 1888 at Trichirapalli in Tamil Nadu. His father was a physics teacher and so it was natural that Raman developed love for this subject. He was a brilliant student from the very beginning. As a brilliant and promising lad, he passed his matriculation examination at the young age of 12 from Madras University.
His parents wanted to send him England for higher studies but his poor health did not allow it.

He studied at Hindu College, Visakhapatnam and Presidency College, Madras. He obtained his post-graduation degree in physics in 1907 with the top position. During his student period he conducted many researches and published his papers in many reputed magazines. In the same year, Raman got the first position in the Financial Service Examination and was appointed as the Assistant Accountant General in Calcutta. There he came in contact with an eminent scientist named Dr. Amritlal Sarkar who was Secretary of the Indian Association for the Cultivation of Science. This contact with Dr. Sarkar proved a turning point in the life of this young scientist.
His interest in physics was deep and lasting and so he continued his research work in his spare time in the laboratory of the Association. He published his research results in the leading journals of Calcutta, which were in regard to the subject of propagation of light. These original research papers were of great scientific significance. When these came to the notice of the then Vice -Challenger of Calcutta University, Sir Ashutosh Mukharjee, he appointed him Professor of physics in the University. During his stay at the University he continued his research with much more devotion and won immense honour and recognition as a physicist.
He was elected the Fellow of the Royal Society of London in 1924. He discovered the “Raman Effect” in 1928. For it he was awarded the Nobel Prize for Physics in 1930. He became the first Indian to win this prestigious honour. With this award, his reputation increased by leaps and bounds and many Universities and institutions of repute honoured him with Ph D and D.Sc. degrees. In December, 1927 he was awarded the Nobel Prize for demonstrating that the nature of X-rays undergoes a change when passed through a matter.
This effect came to be known as the “Compton Effect.” Encouraged by this discovery, Raman continued his experiments and ultimately proved that light rays can also be scattered. His discovery enabled for the first time, the mapping of possible levels of energy gains of molecules and atoms of a substance and thus discovered their molecules and atomic structure. This discovery of the scattering of light led to the development of a simple alternative to infra-red spectroscopy, namely, Raman Spectroscopy. He also gave us the scientific explanation for the blue colour of the sky and the ocean. He explained that the blue color of the ocean was as a result of the scattering of sunlight by the molecules of the water. He travelled widely abroad delivering lectures about his discoveries and researches. In 1933 he became the Director of the Indian Institute of Sciences, Bangalore. In 1943 he founded the Raman Research Institute at Bangalore. He was knighted in 1927. He was awarded the Bharat Ratna in 1954 and the International Lenin Prize in 1957.
  
Principles

K. Chandrasekhara Vincent Raman was born at 7.1888 in the city of Trichinopoly, the presidency of Madras, in British India. Today the city is known as Tiruchirappalli and is located in the Indian state of Tamil Nadu.

Raman's father was Che Rigaud, professor of Mathematics and physics. His mother was family, who learned to read and write for her husband. At the time of the birth of Raman, the family lived with low incomes. Raman was the second of eight children.

The Raman family was Brahman, the Hindu occupation of priests and scholars. His father, however, paid little attention to religious matters: Raman grew up to share his father without further attitude to religion, but he has observed some Hindu cultural rituals and respected traditions such as vegetarianism.

When Raman was four years old, his father got a better job, becoming a college professor, and the family moved to Waltair (now Visakhapatnam).

From a very young age, Raman was interested in science, reading the books that his father had used as a student. As he grew older, he started borrowing books of mathematics and physics from his father's library. In his teenage years, he began to learn books that his father had bought when he wanted to take a master's degree in physics.

Start of a class, 14 years

In 1903, only 14 years old, Raman left for the great city of Chennai (now Chennai) to live in a hostel and to start a bachelor's degree at the University of the presidency. When Raman returned home after his first year at the university, his parents were shaken by his unhealthy appearance; They have set up a house for him in Madras, where he could be cared for by his grandparents.

Raman was very enthusiastic about science. On vacation he would demonstrate experiences of his younger siblings.

He completed his bachelor's degree in 1904 and won medals in physics and English. His British professors encouraged him to study for a master's degree in the UK. However, the Madras civil Surgeons told him that his health was not robust enough to withstand the British climate; He advised Raman to stay in India.

It was probably an excellent tip. The brilliant mathematician Ramanujan, born only a year before Raman, travelled from Madras to work at the University of Cambridge in 1914. Although this has resulted in the creation of some brilliant mathematical works, it has had a serious impact on the health of Ramanujan.

Nobel laureate 18 years Raman error for physics teacher

Raman received a scholarship and remained at the University of the presidency to study his master's degree. His extraordinary potential was acknowledged, and he gained unlimited access to the laboratories, where he pursued the investigations of his own design.

In November 1906, 18, Raman made his first published academic work. At first he had given one of his professors to read, but the professor had not bothered. Raman sent his work directly to the philosophical journal and was accepted. Its title was asymmetrical streaks through a rectangular aperture: it was about the behavior of light.

After the publication of his second role in the philosophical Journal, Raman received a letter from Lord Rayleigh, the eminent British physicist. Rayleigh, not knowing that Raman was just a teenage student, sent his letter to "Professor Raman".

In 1907, 19, Raman has awarded a Master's degree in physics, the highest award.

Fulltime government administrator, part-time scientist

Although Raman was engaged in a scientific career, his brother persuaded him to rely on the examinations of the public administration. The jobs of the public administration were very well paid and his family was deeply indebted.

For 10 years Raman worked as an officer in the Department of Indian Finance in Calcutta (now Kolkata) and quickly rose to a higher position. In his spare time, he carried out research into the physics of instruments and string drums. He has done this work on the Indian Association for the Culture of Science ("" ").

The castle was Hibernating until Raman stumbled upon him and to revive him. In addition to his research work, Raman has given public lectures in Calcutta popularizing science.

Finally, full time science

Although it was a chair of research, Raman also decided to teach the courses: He was an exciting teacher and inspired his students.

The Raman effect

Raman and Rayleigh dispersion

Lord Rayleigh, who had believed that the papers of the young Raman were the work of a professor, was one of the great physicists of his time. He won the 1904 Nobel Prize in Physics.

Its significance for the history of Raman is that Rayleigh was the first to explain why the sky is blue. He had then declared the color of the sea by saying that it was simply a reflection of the color of the sky.

One day, in the summer of 1921, Raman was on the deck of a ship in the Mediterranean on the way to the British Empire Universities Congress in Oxford. He looked at the beautiful blue color of the Mediterranean and to doubt the Rayleigh explanation of its color.

Rayleigh had correctly stated that the sky looks blue due to a phenomenon that is now called the Rayleigh dispersion.

Rayleigh scattering

Approximate representation of the Rayleigh dispersion in the terrestrial atmosphere.

If the earth had no atmosphere, someone who was here through these circumstances would see a white sun and a black sky. This is not what we see, however, because the sunlight interacts with the gases in the Earth's atmosphere.

Instead of directly in our eyes from the sun, the sunlight disperses in all directions through the atmosphere. The blue light is more dispersed, which means that it comes to our eyes from all over the sky, so that the sky looks blue. The yellow and red light scatters at least, so we usually see a yellow sun, and sometimes a red sun.

The Rayleigh dispersion is elastic. This means that photons of light do not lose the energy when they interact with the gas molecules. The light is therefore kept of the same color.

Raman discovers that the sea disperses the light

When he sailed to India in September 1921 Raman, an indefatigable scholar, had to rub with him some simple physics devices: A prism, a miniature spectroscopy, and a grating. He used them to study the sky and the sea and reached the conclusion that the sea diffused the light.

Therefore, if Rayleigh said that the color of the sea is simply a reflection of the color of the sky, it was not quite right. Raman reported on his discoveries in a letter to the nature journal.

When he returned to his laboratory, Raman and his students began a comprehensive research programme on the Diffusion of light.

Compton shows inelastic dispersion

At 1923 Arthur Compton in St. Louis, USA released a new and exciting work showing that X-rays can lose energy when interacting with electrons. X-rays give a portion of their energy to electrons, then move to bring less energy. In other words, Compton has shown that elastic diffusion is possible.

Compton received the 1927 Nobel Prize in Physics for this discovery, known as the Compton effect.

The importance of the Compton effect is that in classical electrodynamics, the diffusion of X-rays and other electromagnetic radiation must always be elastic. Compton's results coincide with quantum theory and not classical theory.

The inelastic dispersion discovered by Compton caused an increase in the X-ray wavelengths. If the elastic dispersion and thus the wavelengths were possible for visible light, then the color of the light would change.

The Raman effect

Raman and his students have continued to investigate the dispersion of light in gases, liquids and solids.

They used the monochrome light sunlight that had been filtered to leave a single color-and found that a variety of different liquids-60 of them-actually changed the color of the light. They first observed the April 1923, but very weak.

In 1927, they found a particularly strong color change in light scattered by glycerin (then called glycerin):

The Raman team observed the impact on gases, crystals and glass. The effect may have been mistaken for fluorescence, another phenomenon in which the light changed its color, but in Raman work the light dispersed by the liquids Polarized that spread the fluorescence.

What became known as the Raman effect-a color change accompanied by the polarization-n ' avait never seen before. The inelastic dispersion in his heart was a more, very strong affirmation of quantum theory.

 

Approximate appearance of the Raman effect

Raman effect

(a) The blue light approaches a molecule, then (b) The green light of the low energy leaves the molecule. It is an elastic dispersion: the light has given a part of its energy to the molecule, making it vibrate more strongly.

The Raman effect is a very small effect compared to the dispersion of the Rayleigh. Only about 1 in 10 million photons are subject to the elastic dispersion.

Raman and his colleague Kaki Krishnan reported on their discovery in March 1928 in nature.

Raman received the 1930 Nobel Prize in Physics to "work on the diffusion of light and by discovering the effect that bears the name."

Raman spectroscopy

Raman has shown that the energy of the dispersed photons is inelastically dispersed as a "footprint" of the substance of light. Raman spectroscopy is therefore used in chemical laboratories around the world to identify substances. It is also used in medicine to study living cells and tissues-also by detecting cancer-without damaging. Laser light instead of sunlight is used as a source of photons.

Photon spin

In 1932 Raman and his student Suri Bhagavantam discovered that bright photons have a angular momentum-quantum terms have photons a property called spin.

Light and other forms of electromagnetic radiation pass their angular dynamics to the atoms that absorb them.

Some personal data and the end

Raman married Lokasundari Ammaal en 1907. The couple had two children: this was a famous astronomer and Che.

Raman was named Chevalier en 1929 for his discovery of the Raman effect and became Sir K. Chandrasekhara Vincenta Raman.

The winning work of the Nobel Raman Prize was first inspired by the comments he made on a maritime voyage. By the way, it was during a ride at sea that another Nobel laureate, Subrahmanyan Che, performed most of his work as a Nobel laureate. And still occasionally, C.V. Raman was Che's uncle!

Raman had the highest confidence in its own capacity. When the president of Palit's physics was donated to the University of Calcutta, one of the conditions was that the incumbent operator would conduct research in other countries to strengthen Indian expertise. Raman refused to do that. He said that scientists from other countries should come to learn from him. I was so sure that I would win the 1930 Nobel Prize, that I had announced tickets for Sweden four months before the winner.

In 1933, Raman became the first Indian director of the Indian Institute of Science in Bangalore. In 1947, he became the first independent national teacher in India. In 1948, he founded the Raman Research Institute in Bangalore, where he worked until the end of his life.

He was cautious that governments played a role in basic research and rejected state funding for their work:

K. Chandrasekhara Vincenta Raman died, 82 years, heart disease November 21, 1970 in Bangalore, India