Thursday, December 9, 2010

Enrico Fermi (1901- 1954)

Enrico Fermi was a famous Italian physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics. He was awarded with Nobel Prize in 1938 for "his discovery of new radioactive elements produced by neutron irradiation, and for the discovery of nuclear reactions brought about by slow neutrons."

Enrico Alberto Fermi was born in Rome, the capital of Italy, on September 29, 1901. His father, Alberto Fermi had no formal education, but with sheer hard work and sincerity he had reached the post of a regional head of the railroad. Enrico’s mother was a primary school teacher. Enrico was the youngest child among three Fermi children born in three consecutive years. He was an energetic and imaginative student prodigy in high school and decided to become a physicist. His mother did not keep well at the time of his birth. So, he was sent to the countryside. He returned after three years to meet his elder brother and they got along very well. They made many toys, including various models of airplanes and battery driven cars.

When Enrico was 14, his elder brother met an untimely death. This incident saddened him. It was a shock to his mother, who could not bear this loss. Shy and reserved, Enrico could not imagine a life without his elder brother. However, his elder brother’s classmate Enrico Persico came in to fill the void. Not only their names, they also shared interests and views. They started working together on various experiments. Together they developed the theory of gyroscope based on the lines of force of the earth’s magnetic field.

In 1918, at the age of 17, he entered the college, which is associated with the University of Pisa. He wrote a detailed essay on vibrating fibers which earned him a scholarship. Now, he could easily provide for his education. There, he earned his doctorate at the age of 21 with a thesis on research on X-rays. After a short visit in Rome, Fermi left for Germany with a fellowship from the Italian Ministry of Public Instruction to study at the whose contributions to quantum mechanics were part of the knowledge prerequisite to Fermi’s later work.

In 1926, his paper on the behavior of a perfect, hypothetical gas impressed the physics department of the University of Rome, which invited him to join as a professor of theoretical physics. Within a short time, Fermi brought together a new group of physicists, all of them in their early 20s. In 1926, he developed a statistical method for predicting the characteristics of electrons according to Pauli’s exclusion principle, which suggests that there cannot be more than one subatomic particle that can be described in the same way. The particles which follow Fermi Statistics are called fermions. Protons, electrons and neutrons are fermions.

Here, he met a Jewish student who later became his life-partner. He married Laura Capone in 1928 by whom he had two children, Nella in 1931 and Giulio in 1936. His research work had geared up. More than 30 of his research papers in various fields were published by 1927. Impressed with his work, the Royal Academy of Itlay in 1929, made him the youngest member of the academy. The Italian government conferred on him the title of ‘His Execellency’ and gave him a special dress reserved for the lords, good income and a sword to carry at royal functions. His theoretical work at the University of Rome was of vital importance, but fresh discoveries prompted Fermi to turn to experimental physics. In 1932, the existence of neutron, a neutral particle was discovered by Sir James Chadwick at Cambridge University. The nucleus of an atom consists of protons and neutrons. In 1933, Fermi put forward the theory of beta decay in which a neutron becomes a proton by emitting an electron and antineutrino.

In 1934, Frederic and Irene Joliot-Curie in France were the first to produce artificial radioactivity by bombarding elements with alpha particles, which are emitted as positively charged helium nuclei from polonium. Inspired by this work, Fermi thought of an idea of inducing artificial radioactivity by another method using neutrons obtained from radioactivity beryllium, but reducing their speed. Passing them through paraffin, he found the slow neutrons were especially effective in producing radioactive isotopes. He used this method successfully on a series of elements. When he used uranium (atomic number 92) as the target of neutron bombardment, however, he obtained radioactive substances that could not be identified.

Fermi’s colleagues were inclined to believe that he had actually made a new, transuranic element of atomic number 93; that is, during bombardment, the nucleus of uranium had captured a neutron, thus increasing its mass number followed beta decay to give the element with atomic number 93. Fermi did not make this claim, for he was not certain what had occurred; indeed, he was unaware that he was on the edge of a magnificent discovery the world was unaware of. He modestly observed years later, “We did not have enough imagination to think that a different process of disintegration might occur in uranium than in any other element. Moreover, we did not know enough chemistry to separate the products from one another.” One of his assistants commented that “God, for his own inscrutable ends, made everyone blind to the phenomenon of atomic fission.”

Before this, the Fermis went on a lecture tour round the world. They went to Michigan University for a lecture series in 1930. In 1934, they visited Brazil and Argentina. Meanwhile, the political scene in Italy was changing drastically, Hitler and the Nazis in Germany and Mussolini and the Fascisits in Itlay had become all powerful. The anti-Jewish slogans on the wall disturbed Fermi because his wife was a Jew.

In December 1938, Fermi was invited to Sweden for receiving the Nobel Prize in Physics. He took permission for himself, wife, two children and their governess to visit Sweden. Sensing the tricky political situation in Italy, he decided to go directly to New York instead of Italy. He had already secured a post at Columbia University. Thus, he continued his work in America.

Meanwhile, in 1938, three German scientists repeated some of Fermi’s early experiments, after bombarding uranium with slow neutrons. Otto Hahn, Lise Meitner, and Fritz Strassmann made a careful chemical analysis of the products formed. On January 6, 1939, they reported that the uranium atom had been split into several parts. Meitner, a theoretical physicist, secretly slipped out of Germany to Stockholm, where, together with her nephew, Otto Frisch, she explained this new phenomenon as a splitting of the nucleus of the uranium atom into barium, krypton and smaller amounts of other disintegration products.

Meitner realized that this nuclear fission was accompanied by the release of stupendous amount of energy by the conversion of some of the mass of uranium into energy in accordance with Einstein’s mass-energy equation, that energy (E) is equal to the product of mass (m) times the speed of light squared (c2), commonly written E=mc2.

Fermi, learnt of this development soon after arriving in New York and realizing its far reaching implications, rushed to greet Niels Bohr on his arrival in New York City. The Hahn-Meitner-Strassmann experiment was repeated at Columbia University, where, after a lot of thinking, Bohr suggested the possibility of a nuclear chain reaction. It was agreed that the uranium-235 isotope, differing in atomic weight from other isotopes of uranium, would be the most effective isotope for such a chain reaction.

Fermi and other eminent scientists like Leo Szilard and Eugene Wegner felt that world peace would be endangered if Hitler’s German scientists use the principle of the nuclear chain reaction to produce the atom bomb. They drafted a letter, which was signed by Einstein. On October 11, 1939, the letter was delivered to the then American President Franklin D Roosevelt Promptly acted on their warning and sanctioned the famous ‘Manhattan Project’ in 1942 to produce the first atom bomb.

Fermi was assigned the task of producing a controlled, self-sustaining nuclear chain reaction. If we burn a piece of paper, it catches fire at one corner, then the sides and ultimately the entire area. The chain reaction is similar to this process. He designed the necessary apparatus, which consisted of graphite and heaps of uranium and uranium oxide. He used approximately six tons of metal in it. He also inserted cadmium strips into it to control the speed of the process. It was named atomic pile by Fermi. On December 2, 1942, Fermi led the team of scientists who, in a laboratory established in the squash court in the basement of stag field at the University of Chicago, achieved the first self-sustaining chain reaction.

Let us see the chain reaction from close quarters. A neutron collides with the uranium nucleus and with a blast it divides it into two parts, creating energy. At this time two or three neurons are ejected and a large amount of energy is released. The new neutrons then go on to repeat the same process with other nuclei takes place producing immense energy. The testing of the first nuclear device, at Alamogordo Air Base in New Mexico on July 16, 1945, was followed by the dropping of atomic bombs on Hiroshima and Nagasaki on August 6 and 9, 1945, respectively.

At the Metallurgical Laboratory of the University of Chicago, Fermi continued his studies of the basic properties of nuclear particles, with particular emphasis on mesons, which are the quantized form of the force that holds the constituents of the nucleus together. He worked as a consultant in the construction of the synchrocyclotron, a large particle accelerator at the University of Chicago. In 1950, he was elected a foreign member of the Royal Society of London.

Fermi made highly original contributions to theoretical physics, particularly to the mathematics of subatomic particles. Moreover, his experimental work in neutron – induced radioactivity led to the first successful demonstration of nuclear fission, the basic principle of both nuclear power and the atomic bomb. The atomic pile in 1942 at the University of Chicago released for the first time a controlled flow of energy from a source other than the Sun; it was the forerunner of the modern nuclear matter for peaceful purpose. Fermi’s name has been commemorated in physics in various ways. Element 100, fermium and the unit of length 10 -15 meters the Fermi, were named after him, as was the National Accelerator Laboratory, Fermilab, at Batavia, near Chicago.

It is a general belief in the world of scientists that two masterminds worked towards the attainment of this dream project-Albert Einstein and Enrico Fermi. The American Atomic Energy Commission awarded Fermi $ 25000 in November 1954, for his contribution in the development of an atom bomb. He died of cancer just 12 days later. Today, scientists are working to use radiation to cure the disease that killed Enrico Fermi.

Wednesday, December 8, 2010

Max Planck (1858 – 1917)

Max Planck was a German physicist and considered as the founder of the quantum theory, and thus one of the most important physicists of the twentieth century. He was a man of strong spirit and great will power Planck was awarded the Nobel Prize in Physics in 1918.

Max Karl Ernst Ludwig Planck was born on April 23, 1858, in the Baltic seaport city of Kiel, Germany. Kiel was then ruled by Denmark. Max was the sixth child of a distinguished professor of law at kiel. Soon, Kiel was freed from Denmark with the German army’s help. His father then joined as professor of Law at the Munich University. Max came from a distinguished and educated family. His relatives had earned name and fame in the fields of law, public services as administrators, and as scientists and preachers among others.

When Max was 9 years old, his father shifted the family from Kiel to Munich as he was appointed professor at the Munich University. Max began his school education at the Maximiliam Gymnasium in Munich. Here, he came in contact with a philosopher and a dedicated professor of physics who inspired and drew him towards physics and mathematics. He was also fond of music. His family would support and encourage him in his musical pursuits. He became a very good pianist and playing piano became a passion of his life time. He would relax playing it after a hard day’s work. He also loved the outdoors, taking long walks each day, hiking and climbing in the mountains during vacations, even when he grew old.

He studied at Munich University from 1874 to 1876 and from 1879 to 1880 and at Berlin University from 1877 to 1878. He had the opportunity to study under the able guidance of professors Hermann Helmholtz and Gustav Kirchhoff. He presented his thesis on the expansion of hydrogen when it was passed through palladium. It earned him doctorate in 1880. This was his first and last experimental research and it lay at the core of the now known as planck’s constant h, in 1900. The value of h found by planck was 6.55 X 10 -27 erg-second, close to the modern value. After his doctorate, he did research in theoretical physics. It did not take long for Planck’s intelligence and brilliance to get noticed. He was appointed assistant professor at Munich University and soon, he moved to Kiel as professor of Theoretical physics. At the age of 31, he was appointed professor of physics at the Berlin University. He was contemporary of the famous physicists Sir J J Thomson and Heirich Hertz.

Max’s intellectual capacities were however, brought to a focus as a result of his independent study, especially of Rudolf Clausius’ writings on thermodynamics. It is a systematic study of the relationship between heat, work, temperature and energy. In fact, thermodynamics and the science of light are closely related. Normally, a thermometer is used to measure temperature up to a certain degree and for temperatures above that, it is determined from the spectrum of the substance. An optical pyrometer is used to measure the temperature of a furnace. Heat and light are in fact types of energy. So, Planck extended his study beyond thermodynamics to study light. He faced some theoretical problems in his research on radiation. He researched on the amount of light needed to produce heat. He discovered that very little amount of heat brightens a substance. Every object has some amount of heat due to which it glows. But in reality it does not happen so! All his calculations were correct. Thus, he felt there were certain loopholes in the established laws regarding light. This revolutionary scientist took up the challenge to question and rejects the age-old prevailing principles.

Planck formulated new principles. He put forward the hypothesis that light is a stream of energy and energy emitted in specific amounts or quanta. According to him, different levels contain different amounts of energy. According to planck, the energy associated with a quantum of radiation is proportional to the frequency of radiation, and the constant of proportionality (now called planck’s constant h) is a universal one. Planck’s new theory came to be known as ‘Quantum theory’. Max planck presented his new theory to the German Science Academy in December 1900. Many scientists present at the meeting did not accept the new theory. They had another reason. They found the age-old theory of light-Copscular Theory or particle theory being revoked here. They felt that the wave theory readily explained reflection, refraction, interference and polarization, etc. of light. So, how could the wave theory be dismissed? They were not mentally prepared to accept this.

At the same time, Albert Einstein was working on his Theory of Relativity in Switzerland. He made it clear that Planck’s Quantum Theory could easily solve some problems of Photo electricity, which the wave theory failed to solve. In 1905, Albert Einstein used Planck’s idea of light quantum hypothesis to explain photoelectric effect which could not be explained using the wave theory of light. In 1913, Einstein arrived at Berlin and the two great scientists of the time came together and became great friends. They shared their common interest in music-playing piano. Einstein contributed significantly in establishing the quantum theory. Steadily, the scientists of the world accepted Planck’s quantum theory. In 1918, he was awarded the Nobel Prize for Physics for his quantum theory of light.

Planck was a man of strong spirit and will power. If he had been less tolerant, less philosophical and had even lesser religious belief, he probably could not have succeeded in overcoming the tragedies that marred his life after his 50’s. In 1909, his first wife, Marie Merck, daughter of a Munich banker, died after 22 years of happy marriage, leaving Planck with two sons and twin daughters. He married again and had three children from the second marriage. He lost his elder son Karl in action in 1916 during World War I. The following year, Margarete, one of his daughters, died in childbirth, and in 1919 the same fate befell Emma, his second daughter. The terror unleashed by the Nazis compelled his two dear friends Albert Einstein and Erwin Schrodinger to leave Germany for good. He was to face further tragedy with the advent of World War II. The house in Berlin where he lived was totally destroyed be bombs in 1944.

The Nazis could not compel Planck to sign the Declaration in favour of Nazism. He was constantly harassed to sign it, but he did not do so. They again approached him in 1944 with even more pressure. Planck was 86 years old then, while his only remaining son Erwin, was in prison accused of being a traitor. They agreed to release Erwin provided Planck signed the Declaration. But Planck categorically refused to sign and as a result, Erwin was shot dead. Later, he lost his property and his personal library in war blitz. This old scientist withstood all the tragedies without forsaking principles which were so dear to him.

Germany suffered a massive defeat at the hands of the allied forces. A new and strong German nation emerged as the Nazi regime came to an end. Nazism lost its grip over the psyche of the people. New German administrators organized a grand function to celebrate the 90th birthday of this great scientist. Unfortunately, he passed away on October 4, 1947, a few months before the big day. The Kaiser Wilhelm Academy of Science was renamed Max Planck Academy of Science in honour of this great man. Moreover, the German medal for foremost research called Max planck medal is awarded every year in his honour.














Scientist Max Planck Photo

Tuesday, December 7, 2010

Johannes Kepler (1571 – 1630)

Johannes Kepler, a mathematician, astronomer and astrologer was born on December 27, 1571 at Wiel der Stadt, Wurtemberg, Germany. He is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation. Students of astronomy still study his theory. His father was a mercenary soldier and his mother was a daughter of an innkeeper. When he was four year old, a bout of smallpox weakened his eyesight and affected his health. Despite such difficulties, young Johannes Kepler was a bright and intelligent boy.

Kepler completed his early education in a local school and then at a nearby seminary for aspiring priesthood. He went on to enroll on a scholarship at the local University of Tubingen, the (as now) a bastion of Lutheran orthodoxy and in 1591, obtained master’s degree in theology. His favorite subjects were mathematics and science. During his study he was introduced to Copernicus’ theories. The way planets revolve round the Sun interested him. He now gave up his ambition of becoming a priest.

In 1594, at the age of 23, he was appointed as lecturer of mathematics at Grates University. He then married a girl from a rich family. Things started looking up and it seemed he had found a definite direction in life. Kepler belonged to the Protestant faith. Communal disturbance and strife forced him to abandon Grates University in 1597. This great mathematician and scientist had a liking for theology. He linked all of life’s incidents with it. He believed that he had no faith in astrology.

When Kepler left Grates University, it so happened that Denmark’s famous astronomer Tycho Brahe had settled in Prague after being banished from his country. Brahe was opposed to the Copernicus theories. He believed more in the Almighty’s universal principles. Brahe’s observations regarding the stars were aplenty. Kepler got an opportunity to work with Brahe. Brahe appointed Kepler as his assistant and torchbearer. Kepler then firmly believed that the sun was the centre of the universe and not the earth.

In 1601 AD, Tycho Brahe passed away, but Kepler’s planetary calculations continued. After analyzing Brahe’s works Kepler came to certain conclusions regarding the motion of planets, which were noteworthy. Thus, the geo-centric (earth at the centre) planetary observations that Ptolemy made were focused on to Copernicus observations that planet revolved round the Sun in circles. Kepler improved upon this theory and proved that the orbits of planets were not in circles but in flattened circles or ellipses. His important observations came to be recognized as Kepler’s Laws. Kepler’s three laws of planetary motion are as follows:-

1) The orbits of the planets are ellipse, with the Sun at one focus of the ellipse.

2) The line joining planet to the Sun sweeps out equal areas in equal times as the planet moves around the Sun.

3) The squares of the periods of any two planets are proportional to the cubes of their mean distance from the Sun.

Kepler concluded further that the Sun has a major influence on the motion of planets. Some magnetic force worked between the Sun and the planets. After almost half a century, Isaac Newton propounded the Lows of Motion and Gravitation. Even today Kepler’s and Newton’s laws are considered path-breaking.

He had made a deep study of human sight and telescope. This way he laid the foundations for the development of telescopes for the study of celestial bodies.

Regarding Kepler’s novel discovery that planets move in elliptical orbits around the Sum, many feel it is incomplete. There is regular change in the planetary motions around the Sun. Through calculations he also concluded how much time celestial bodies take to complete one orbit around the Sun take less time in orbit. It can be said that Johannes Kepler’s discoveries would have contributed a great deal to the Laws of Gravitation propounded by Isaac Newton. 12 years before Isaac Newton was born, this great scientists died in 1630 of fever at Regensburg at the age of 60.











Johannes Kepler Photo

Saturday, December 4, 2010

Prof. J. J. Chinoy (1909 – 1978)

India’s great scientist and Gujarat’s famous Jamshedji Chinoy was born on February 19, 1909 in Kachchh-Bhuj. He was the son of Jijabhai & Gulbai Chinoy. He had his college education in Mumbai. In 1929, he cleared B.Sc. in Botany with a first class with distinction from Mumbai University. After losing his father at a very young age, he was brought up by his grandfather. Some years later, his grandfather too, passed away. With courage and hard work he surged forward. Considered a bright student in school and college, he regularly took part in various debates.

Having stood first at the graduate level in his subject, he was awarded the Dakshina Fellowship by Mumbai’s Government College, better known as Royal Institute of Science at that time. Besides, he received Mumbai University’s Research Fellowship. In 1931, he cleared MSc. with first class honours. Because of his promising career and good results; after he completed post- graduation, he went to Britain on a Research Fellowship. To do Ph D from London University, he joined the Imperial College. There he had the unique opportunity to undertake research under the guidance of work-renowned botanist professor F G Gregory. In 1935, he was awarded the Ph D degree by London University.

After completing PhD he returned to India and joined the Central Cotton Committee at Layalpur as physiological assistant. In 1941, he joined the Indian Agriculture Research Institute as Assistant Economical Botanist. When India attained independence, more doors opened for brilliant research scientists. Meanwhile, this brilliant research scientist was invited to join as Reader at the botany department of Delhi University. He accepted it wholeheartedly. Thus, he became associated with university education. He taught for 22 years at the post-graduate level and was engaged in research. Many of his research papers were published during this time. He also actively participated in many research workshops and seminars abroad.

In 1959, when he got the opportunity to join Gujrat University, he snapped it to serve his native place. He joined as professor and head of the botany department. Meanwhile, from 1962 to 1974, he was also the director of the University School of Sciences. For the last 50 years he was engaged in pure and applied research. His research work received recognition form various institutes and the science world. In 1959, at the ninth International Botany Congress held at Montreal in Canada, he headed the plant physiology section. In 1961 for his outstanding research, Gujrat University awarded his the Dr. K G Naik gold medal. In 1964, he was specially invited to represent India and take active part in the discussions at the tenth International Botany Congress in Edinborough. In 1975, he was selected as the working vice-president of the twelfth International Botany Congress held at Leningrad in Russia. At this congress he was awarded a special medal for his exceptional research work.

Besides, Chinoy also visited the world-famous biological research schools in England, Holland, France, Germany, Belgium, Sweden, Norway and Russia. In many of these countries he honoured the invitation extended to him by the science academies to lecture in their lecture series. He was appointed Fellow of Indian Academy of Science. Besides, there was a demand for his lectures at the botany seminars held at Bhavnagar, Vadodara , Kolkata and other places in India. In these seminars he was invited as president, vice-president or chief speaker. Wherever possible he would go, there would be exchange of thoughts and others would be benefited by his knowledge. He was the patron member of the Plant physiology Society of India, besides serving as honorary secretary, vice-president and president. The prestigious Rafi Ahmed Kidwai Memorial Prize awarded every year by the New Delhi based Indian Council for Agriculture Research, was awarded to Chinoy for 1974-75, for his agriculture botanical research.

Chinoy had developed a plant strain with disease-free and fast growing seeds besides seeds that required less water and could be grown during droughts. He contributed immensely towards cellular and molecular biology. More than 250 research papers of his were published in national and international magazines. Under his leadership a group of leading scientists was working on plant physiology at Gujrat University. This group received recognition in India and abroad. Under his able guidance more than 100 students got their PhD degrees. These students are holding high posts in well-known research institute within the country and abroad. Till his last breath, Chinoy rendered service in this field. Even after retirement he continued his honorary services. Under the aegis of the University Grants Commission, New Delhi, Chinoy conceived the book ‘Role of Ascorbic Acid in Plant Metabolism’. This great scientist who believed in the adage ‘Work is Worship’ remained active till the end of his life.

Chinoy was an optimist and mild-mannered. Nobody ever found him furious. Punctuality and discipline were his watchwords. He cared for his students, employees and co-workers. He understood their personal problems and always tried to help them. He believed that if there is no teamwork there could be no worthwhile research even though the laboratory is well-equipped. With a smiling face he would enter the department on time and the entire department would liven up. It was said that he had a sweet tooth. His voice and speech too, were melodious and sweet-sounding.

On March 12, 1978 at the age of 69 years, the country’s great scientist Chinoy took leave from us forever. He has departed mortally, but left a body of sincere students behind. We will always remember this honest son of the soil and scholar of Gujrat through his works.