Friday, December 31, 2010

What are radioisotopes?

Many of the chemical elements have a number of isotopes. The isotopes of an element have the same number of protons in their atoms (atomic number) but different masses due to different numbers of neutrons. In an atom in the neutral state, the number of external electrons also equals the atomic number. These electrons determine the chemistry of the atom. The atomic mass is the sum of the protons and neutrons. There are 82 stable elements and about 275 stable isotopes of these elements.

When a combination of neutrons and protons, which does not already exist in nature, is produced artificially, the atom will be unstable and is called a radioactive isotope or radioisotope. There are also a number of unstable natural isotopes arising from the decay of primordial uranium and thorium. Overall there are some 1800 radioisotopes.

At present there are up to 200 radioisotopes used on a regular basis, and most must be produced artificially.

Radioisotopes can be manufactured in several ways. The most common is by neutron activation in a nuclear reactor. This involves the capture of a neutron by the nucleus of an atom resulting in an excess of neutrons (neutron rich). Some radioisotopes are manufactured in a cyclotron in which protons are introduced to the nucleus resulting in a deficiency of neutrons (proton rich).

The nucleus of a radioisotope usually becomes stable by emitting an alpha and/or beta particle (or positron). These particles may be accompanied by the emission of energy in the form of electromagnetic radiation known as gamma rays. This process is known as radioactive decay.

Radioactive products which are used in medicine are referred to as radiopharmaceuticals.

Isotopes used in Medicine

Many radioisotopes are made in nuclear reactors, some in cyclotrons. Generally neutron-rich ones and those resulting from nuclear fission need to be made in reactors, neutron-depleted ones are made in cyclotrons. There are about 40 activation product radioisotopes and five fission product ones made in reactors.

Reactor Radioisotopes (half-life indicated)

Bismuth-213 (46 min): Used for targeted alpha therapy (TAT), especially cancers, as it has a high energy (8.4 MeV).

Chromium-51 (28 d): Used to label red blood cells and quantify gastro-intestinal protein loss.

Cobalt-60 (5.27 yr): Formerly used for external beam radiotherapy, now used more for sterilising

Dysprosium-165 (2 h): Used as an aggregated hydroxide for synovectomy treatment of arthritis.

Erbium-169 (9.4 d): Use for relieving arthritis pain in synovial joints.

Holmium-166 (26 h): Being developed for diagnosis and treatment of liver tumours.

Iodine-125 (60 d): Used in cancer brachytherapy (prostate and brain), also diagnostically to evaluate the filtration rate of kidneys and to diagnose deep vein thrombosis in the leg. It is also widely used in radioimmuno-assays to show the presence of hormones in tiny quantities.

Iodine-131 (8 d)*: Widely used in treating thyroid cancer and in imaging the thyroid; also in diagnosis of abnormal liver function, renal (kidney) blood flow and urinary tract obstruction. A strong gamma emitter, but used for beta therapy.

Iridium-192 (74 d): Supplied in wire form for use as an internal radiotherapy source for cancer treatment (used then removed).

Iron-59 (46 d): Used in studies of iron metabolism in the spleen.

Lutetium-177 (6.7 d): Lu-177 is increasingly important as it emits just enough gamma for imaging while the beta radiation does the therapy on small (eg endocrine) tumours. Its half-life is long enough to allow sophisticated preparation for use. It is usually produced by neutron activation of natural or enriched lutetium-176 targets.

Molybdenum-99 (66 h)*: Used as the 'parent' in a generator to produce technetium-99m.

Palladium-103 (17 d): Used to make brachytherapy permanent implant seeds for early stage prostate cancer.

Phosphorus-32 (14 d): Used in the treatment of polycythemia vera (excess red blood cells). Beta emitter.

Potassium-42 (12 h): Used for the determination of exchangeable potassium in coronary blood flow.

Rhenium-186 (3.8 d): Used for pain relief in bone cancer. Beta emitter with weak gamma for imaging.

Rhenium-188 (17 h): Used to beta irradiate coronary arteries from an angioplasty balloon.

Samarium-153 (47 h): Sm-153 is very effective in relieving the pain of secondary cancers lodged in the bone, sold as Quadramet. Also very effective for prostate and breast cancer. Beta emitter.

Selenium-75 (120 d): Used in the form of seleno-methionine to study the production of digestive enzymes.

Sodium-24 (15 h): For studies of electrolytes within the body.

Strontium-89 (50 d)*: Very effective in reducing the pain of prostate and bone cancer. Beta emitter.

Technetium-99m (6 h): Used in to image the skeleton and heart muscle in particular, but also for brain, thyroid, lungs (perfusion and ventilation), liver, spleen, kidney (structure and filtration rate), gall bladder, bone marrow, salivary and lacrimal glands, heart blood pool, infection and numerous specialised medical studies. Produced from Mo-99 in a generator.

Xenon-133 (5 d)*: Used for pulmonary (lung) ventilation studies.

Ytterbium-169 (32 d): Used for cerebrospinal fluid studies in the brain.

Ytterbium-177 (1.9 h): Progenitor of Lu-177.

Yttrium-90 (64 h)*: Used for cancer brachytherapy and as silicate colloid for the relieving the pain of arthritis in larger synovial joints. Pure beta emitter and of growing significance in therapy.

Radioisotopes of caesium, gold and ruthenium are also used in brachytherapy.

Cyclotron Radioisotopes

Carbon-11, Nitrogen-13, Oxygen-15, Fluorine-18: These are positron emitters used in PET for studying brain physiology and pathology, in particular for localising epileptic focus, and in dementia, psychiatry and neuropharmacology studies. They also have a significant role in cardiology. F-18 in FDG (fluorodeoxyglucose) has become very important in detection of cancers and the monitoring of progress in their treatment, using PET.

Cobalt-57 (272 d): Used as a marker to estimate organ size and for in-vitro diagnostic kits.

Copper-64 (13 h): Used to study genetic diseases affecting copper metabolism, such as Wilson's and Menke's diseases, and for PET imaging of tumours, and therapy.

Copper-67 (2.6 d): Beta emitter, used in therapy.

Fluorine-18 as FLT (fluorothymidine), F-miso (fluoromisonidazole), 18F-choline: tracer.

Gallium-67 (78 h): Used for tumour imaging and localisation of inflammatory lesions (infections).

Gallium-68 (68 min): Positron emitter used in PET and PET-CT units. Derived from germanium-68 in a generator.

Germanium-68 (271 d): Used as the 'parent' in a generator to produce Ga-68.

Indium-111 (2.8 d): Used for specialist diagnostic studies, eg brain studies, infection and colon transit studies.

Iodine-123 (13 h): Increasingly used for diagnosis of thyroid function, it is a gamma emitter without the beta radiation of I-131.

Iodine-124: tracer.

Krypton-81m (13 sec) from Rubidium-81 (4.6 h): Kr-81m gas can yield functional images of pulmonary ventilation, e.g. in asthmatic patients, and for the early diagnosis of lung diseases and function.

Rubidium-82 (1.26 min): Convenient PET agent in myocardial perfusion imaging.

Strontium-82 (25 d): Used as the 'parent' in a generator to produce Rb-82.

Thallium-201 (73 h): Used for diagnosis of coronary artery disease other heart conditions such as heart muscle death and for location of low-grade ly

Neutrinos

You can't see them but they're everywhere. There are 60 billion in front of your nose this second. You can't smell them. You can't taste them when they touch your tongue. You can't hear them. You can't feel them when they pass through you. 10,000,000,000,000,000 will do it while you read this page and you will never know. They are neutrinos, the ``little neutral ones'' in the family of subatomic particles. Neutrinos hold secrets from the earliest days of the universe. They bring us information from deep inside exploding stars and from high energy particle collisions. Their presence may signal unexpected phenomena. Measuring their properties will help us understand how the universe will evolve.

We need large detectors to detect neutrinos, because neutrinos don't interact with matter very often. Most subatomic particles are very interactive. For example, quarks, which make up most of ordinary matter, are so active in our detectors that it is difficult to sort out the patterns that they leave. The electron is another highly evident particle -- and reliable, too. You can count on finding electrons inside your typical wall outlet and also inside your typical particle interaction. But the neutrino is different from the rest. Their interactions occur far more rarely. At the highest energy accelerator in the world, Fermilab, it is oobserved that neutrino reactions 10,000,000,000 times less often than those of quarks. They just quietly zip through the detector and go on their merry way.

Neutrino research is fascinating today because the results are full of contradictions. For fifty years, all of the evidence pointed to neutrinos being bundles of moving energy that had no mass -- a pretty weird concept for a particle. But recently we discovered a novel behavior which can only be explained if neutrinos do have mass. How do resolve this conflict?

If the neutrino has mass, it must be very, very small. It would take at least half a million neutrinos to tip the scales on the electron. Still, such a wispy particle will have a big effect in the universe. The collective mass of the neutrinos rivals the mass of all the stars! Given the discovery of mass, we can begin asking even more exciting questions. The Big Bang, for example, produced a million neutrinos in every gallon of space. The holy grail of neutrino physics is to detect these relics. Their mass may hold the key.

All of that sounds pretty esoteric, and you may ask: ``What have neutrinos done for me lately?'' Actually, they matter a lot to you. They are part of the ignition process of the sun. They play a role in heating the center of the earth, causing continental drift. So the next time you see a koala, whose evolution depended on living on an isolated continent, thank a neutrino! The tools that physicists use to create and study neutrinos have direct benefit to every one of us. One fork of the beam line for the neutrino experiment at the Fermilab goes to Neutron Therapy, a very successful cancer treatment method. The extremely clean laboratory environment of state-of-the-art solar neutrino experiments can be used for sensitive tests to monitor violations of the nuclear test ban treaty.

Saturday, December 11, 2010

Galileo Galilei

Basic Information:

 

Nationality: Italian

Religion: Roman Catholic 

Born: February 15, 1564

Death: January 8, 1642

 

Education and Academic Positions:

 

Born in Pisa to Vincenzo Galilei, a famous lutenist and musical theorist, Galileo was a devout Catholic who seriously considered pursuing a career in the priesthood. Instead, at his father's urging, he enrolled at the University of Pisa to study medicine, but switched to mathematics. He was appointed the chair of mathematics in 1589. In 1592 he moved to the University of Padua, teaching in the fields of mathematics, geometry, and astronomy until 1610.

 

Galileo - the Father of Science:

 

Among other things, Galileo has been called: The father of science (by Albert Einstein), The father of modern physics, The father of modern astronomy, The father of observational science

 

Stephen Hawking (among others) have observed that Galileo probably contributed more to the creation of the modern natural sciences, and the scientific method, than any other single figure in history.

 

Specifically, Galileo focused on observation and experimentation, rather than creating abstract theories that were not tested. He also was one of the first scientists to provide mathematical descriptions of the laws of physics.

 

Kinematics:

 

Some of Galileo's most significant work was in the field of kinematics, identifying that the total distance covered is proportional to the square of the time. He also identified the parabola as the ideal trajectory for uniformly accelerated motion in a plane.

 

Galileo also studied the motion of a pendulum, realizing that a pendulum swing is constant regardless of amplitude (at least to small angle approximations).

 

He proposed a principle of inertia, which became the foundation of Newton's First Law of Motion. Though this concept had been put forth by others, Galileo was the first to formalize it mathematically.

 

Astronomy, the Telescope, & the Heliocentric Universe:

 

In 1608, the telescope was invented in the Netherlands. Over the next year, Galileo had heard about it and crafted his own improvements. With the improved telescope, he was able to observe the heavens more closely than ever before and identified three of Jupiter's moons. This, along with observing the phases of Venus, provided support for the Copernican heliocentric model of the universe over Ptolemy's geocentric model.

 

In addition, he made many other significant observations. He was the first to observe sunspots, the rings of Saturn (though he didn't know what to make of him), and lunar mountains and craters.

 

Galileo's First Controversy:

 

Galileo's support of a heliocentric theory was seen by the Roman Catholic Church as contradicting various scriptural passages.

 

In 1616, Galileo first defended himself against the Church. Galileo was ordered not to "hold or defend" the idea that the Earth moved and the Sun remained stationary at the center. For several years, Galileo was able to discuss heliocentric theory hypothetically without arousing undue ire from the Church.

 

Galileo's Trial:

 

In 1632, Galileo published Dialogue Concerning the Two Chief World Systems with the permission of Pope Urban VII, who had supported Galileo in the earlier conflict (as Cardinal Barberini).

 

Urban had two conditions:

 

Galileo was to include arguments for both heliocentric and geocentric viewpoints Urban's own views on the matter were to be included. Unfortunately, the book turned out to be biased in favor of heliocentrism and the Pope did not appreciate the perceived public ridicule. Galileo was ordered to stand trial for suspicion of heresy in 1633.

 

Galileo's Imprisonment:

 

The 1633 hearing did not go as well as the one in 1616, and Galileo was found guilty of heresy. His sentence had three parts: He was required to recant his heliocentric views. He was imprisoned (though this later got commuted to house arrest at his estate near Florence). His Dialogue was banned, and all other works written by him (or to be written by him) were forbidden, though this latter part was not enforced. While under house arrest, Galileo wrote Two New Sciences, which outlined his earlier work in kinematics and the strength of materials. This book was praised by both Sir Isaac Newton and Albert Einstein.

 

Galileo's Death & Redemption:

 

Galileo died of natural causes in 1642, after having gone blind. He was reburied at Santa Croce, sacred ground, in 1737. In 1741, Pope Benedict XIV authorized publication of Galileo's complete works. Heliocentrism was formally rescended as heresy in 1758. It was not until October 31, 1992, that the Church under Pope John Paul II expressed regret over how Galileo had been treated, in response to a Pontifical Council for Culture study.

 

Galileo Galilei is one of the most influential and famous scientists in human history, having contributed to a wide range of fields and establishing the mathematical and experimental foundations of modern physics and astronomy.

 

Some questions and answers

What is Physics?

 

Physics is the scientific study of matter and energy and how they interact with each other. This energy can take the form of motion, light, electricity, radiation, gravity . . . just about anything, honestly.

 

Physics deals with matter on scales ranging from sub-atomic particles (i.e. the particles that make up the atom and the particles that make up those particles) to stars and even entire galaxies.

 

What is Quantum Physics?

 

Quantum physics is the study of the behavior of matter and energy at the molecular, atomic, nuclear, and even smaller microscopic levels. In the early 20th century, it was discovered that the laws that govern macroscopic objects do not function the same in such small realms.

 

What Does Quantum Mean?

 

"Quantum" comes from the Latin meaning "how much." It refers to the discrete units of matter and energy that are predicted by and observed in quantum physics. Even space and time, which appear to be extremely continuous, have smallest possible values.

 

Who Developed Quantum Mechanics?

 

As scientists gained the technology to measure with greater precision, strange phenomena was observed. The birth of quantum physics is attributed to Max Planck's 1900 paper on blackbody radiation. Development of the field was done by Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, Erwin Schroedinger, and many others. Ironically, Albert Einstein had serious theoretical issues with quantum mechanics and tried for many years to disprove or modify it.

 

What's Special About Quantum Physics?

 

Light waves act like particles and particles act like waves (called wave particle duality). Matter can go from one spot to another without moving through the intervening space (called quantum tunnelling). Information moves instantly across vast distances. In fact, in quantum mechanics we discover that the entire universe is actually a series of probabilities. Fortunately, it breaks down when dealing with large objects, as demonstrated by the Schroedinger's Cat thought experiment.

 

 

List of various branches of physics

The different disciplines of physics are listed below. The list will be updated with new additions and definitions as appropriate.

 

  1. Acoustics - the study of sound & sound waves

 

  1. Astronomy - the study of space

 

  1. Astrophysics - the study of the physical properties of objects in space

 

  1. Atomic Physics - the study of atoms, specifically the electron properties of the atom

 

  1. Biophysics - the study of physics in living systems

 

  1. Chaos - the study of systems with strong sensitivity to initial conditions, so a slight change at the beginning quickly become major changes in the system

 

  1. Chemical Physics - the study of physics in chemical systems

 

  1. Computational Physics - the application of numerical methods to solve physical problems for which a quantitative theory already exists

 

  1. Cosmology - the study of the universe as a whole, including its origins and evolution

 

  1. Cryophysics / Cryogenics / Low Temperature Physics - the study of physical properties in low temperature situations, far below the freezing point of water

 

  1. Crystallography - the study of crystals and crystalline structures

 

  1. Electromagnetism - the study of electrical and magnetic fields, which are two aspects of the same phenomenon

 

  1. Electronics - the study of the flow of electrons, generally in a circuit

 

  1. Fluid Dynamics / Fluid Mechanics - the study of the physical properties of "fluids," specifically defined in this case to be liquids and gases

 

  1. Geophysics - the study of the physical properties of the Earth

 

  1. High Energy Physics - the study of physics in extremely high energy systems, generally within particle physics

 

  1. High Pressure Physics - the study of physics in extremely high pressure systems, generally related to fluid dynamics

 

  1. Laser Physics - the study of the physical properties of lasers

 

  1. Mathematical Physics - applying mathematically rigorous methods to solving problems within physics

 

  1. Mechanics - the study of the motion of bodies in a frame of reference

 

  1. Meteorology / Weather Physics - the physics of the weather

 

  1. Molecular Physics - the study of physical properties of molecules

 

  1. Nanotechnology - the science of building circuits and machines from single molecules and atoms

 

  1. Nuclear Physics - the study of the physical properties of the atomic nucleus

 

  1. Optics / Light Physics - the study of the physical properties of light

 

  1. Particle Physics - the study of fundamental particles and the forces of their interaction

 

  1. Plasma Physics - the study of matter in the plasma phase

 

  1. Quantum Electrodynamics - the study of how electrons and photons interact at the quantum mechanical level

 

  1. Quantum Mechanics / Quantum Physics - the study of science where the smallest discrete values, or quanta, of matter and energy become relevant

 

  1. Quantum Optics - the application of quantum physics to light

 

  1. Quantum Field Theory - the application of quantum physics to fields, including the fundamental forces of the universe

 

  1. Quantum Gravity - the application of quantum physics to gravity and unification of gravity with the other fundamental particle interactions

 

  1. Relativity - the study of systems displaying the properties of Einstein's theory of relativity, which generally involves moving at speeds very close to the speed of light

 

  1. Statistical Mechanics - the study of large systems by statistically expanding the knowledge of smaller systems

 

  1. String Theory / Superstring Theory - the study of the theory that all fundamental particles are vibrations of one-dimensional strings of energy, in a higher-dimensional universe

 

  1. Thermodynamics - the physics of heat

 

Sunday, September 5, 2010

This essay is written by a Srilankan writer Mr.A.Muthulingam who is now living in Canada. He has written many essays, short stories and novels. I feel, this essay is one of the best essays he has written in his life time. I acknowledge the autor with due respect.

நாளுக்கு ஒரு நன்மை-A.MUTHULINGAM

நான் சிறுவயதில் படித்த பள்ளிக்கூடத்தில் ஒரு வாத்தியார் படிப்பித்தார். காந்தி வாத்தியார் என்று பெயர். ஐந்தடி நாலு அங்குலம் உயரம் இருப்பார். மேல்சட்டை அணியமாட்டார். இரண்டே இரண்டு வேட்டிகள் அவரிடம் இருந்தன. ஒன்று கிழிந்தால்தான் இன்னொரு புதிசு வாங்குவார். காந்திபோல ஒரு போர்வைதான். உரத்துப் பேசத் தெரியாது. சிரிக்கும்போதுகூட இரண்டு ஸ்வரத்தில் மட்டும் சிரிப்பார். காந்தி வைத்திருந்ததுபோல உயரமான தடியை அவர் வைத்திருக்கவில்லை. மற்றும்படிக்கு காந்தியைப் போலவே நடந்துகொண்டார். அவர் என் அண்ணனைப் படிப்பித்தார்; தங்கையை படிப்பித்தார்; தம்பியை படிப்பித்தார். ஆனால் என் வகுப்பை அவர் படிப்பிக்கவே இல்லை. ஆனாலும் எனக்கு அவரிலே பிரியம் இருந்தது. அவர் அந்த வயதில் எனக்கு சொன்னது 'ஒரு நாளைக்கு ஒரு நன்மை செய்தால் போதும்' என்பது. அது சொல்லி பல வருடங்களாகிவிட்டது என்றாலும் அதை இன்னும் அவ்வப்போது நான் கடைப்பிடித்து வந்தேன். பெரிதாக ஒன்றும் இல்லை. பெரியவர்களுக்கு வணக்கம் சொல்வது; அஞ்சல் பெண்ணுக்கு நன்றி கூறுவது; முன்பின் தெரியாத ஒருவரைப் பார்த்து முறுவல் செய்வது. அவ்வளவுதான். இரண்டு நாட்களுக்கு முன்னர் என் நண்பர் தொலைபேசியில் அழைத்திருந்தார். ஏதோ பேச்சில் காந்தி வாத்தியாருடைய பெயர் வந்தது. அவரும் மனைவியும் கஷ்டத்தில் இருக்கிறார்கள் என்றார். எனக்கு காந்தி வாத்தியாருடன் 50 வருடங்களுக்கு மேலாக தொடர்பே இல்லை. எனினும் இன்றைய என் நன்மை இதுதான் என்று தீர்மானித்து நண்பரிடம் முகவரி பெற்று காந்தி வாத்தியாருக்கு என்னால் இயன்ற சிறு தொகை பணம் அனுப்பிவைத்தேன். இங்கே சிறுதொகை ஆனால் இலங்கையில் அது பெரும் கொடை. அனுப்பியதுடன் அதை மறந்துபோனேன்.

அவர் பற்றிய சின்னச் சின்ன சம்பவங்களை மறக்க முடியவில்லை. நான் புதுப் பாடப் புத்தகம் வாங்கியதும் அதற்கு மாட்டுத்தாள் கடதாசியில் உறைபோட்டு கொண்டுபோய் என்னுடைய பெயரை எழுத காந்தி வாத்தியாரிடம் கொடுப்பேன். புத்தகங்களில் பெயர் எழுதித் தருவது அவர்தான். அவர் என் பெயரை நான் எதிர்பார்த்த மாதிரி முன்பக்கத்திலோ, மட்டையிலோ எழுதாமல் இருபதாம் பக்கத்தில் எழுதினார். ஏன் என்று கேட்க பதில் சொல்லவில்லை ஆனால் 'புத்தகம் பத்திரம்' என்றார். அப்பொழுது எங்கள் பள்ளிக்கூடத்தில் புத்தகங்கள் களவு போய்க்கொண்டிருந்தன. இரண்டே இரண்டு நாளில் என் புத்தகமும் களவு போனது. நான் காந்தி வாத்தியாரிடம் போய் முறைப்பாடு செய்தேன். அங்கே படிப்பித்த எல்லா வாத்தியார்களிலும் இவரிடம் தான் பிரம்பு என்ற பொருள் இல்லை, அடிக்கவும் மாட்டார். ஆனாலும் இவரைத்தான் நான் தெரிவு செய்தேன்.

மாணவர்களிடம் அவர் கேட்கும் முதல் கேள்வி 'இன்று என்ன நன்மை செய்தாய்?' ஒரு நாளைக்கு ஒரு நன்மை என்பது அவர் உபதேசம். ஒரு மாணவன் 'ஏன் சேர் இரண்டு நன்மை செய்யக்கூடாதா?' என்று கேட்டான். அவர் 'அது பேராசை, ஒரு நாளைக்கு ஒன்று போதும்' என்பார். காந்தி வாத்தியார் எங்கள் வகுப்புக்குள் நுழைந்து எல்லோருடைய புத்தகங்களையும் வாங்கி ஒற்றையை தட்டிப் பரிசோதித்த பின்னர் திருப்பி கொடுத்துவிட்டு போனார். பள்ளிக்கூடம் முடிந்த பிறகு என்னையும், எப்பொழுதும் வகுப்பில் கடைசி வாங்கில் குடியிருக்கும் கிருட்டிணபிள்ளை என்பவனையும் தன் வகுப்பறைக்கு கூப்பிட்டார். கிருட்டிணபிள்ளை உயரமானவன். ஒரு கண்ணாடி யன்னலுக்கு பின்னால் நின்று முகத்தை அழுத்திப் பார்ப்பதுபோல சப்பையான முகம். அவன் முன்னாலே ஏதோ பரிசு வாங்கப் புறப்பட்டதுபோல நடந்துபோக நான் பின்னால் போனேன். அவனுடைய புத்தகத்தில் இருபதாம் பக்கம் கிழிக்கப்பட்டிருந்தது. அந்தப் புத்தகத்தை எடுத்து காந்தி வாத்தியார் என்னிடம் தந்தார். அவனுக்கு ஒரு புதுப் புத்தகம் தன் காசில் வாங்கிக் கொடுத்தார். கிருட்டிணபிள்ளை ஓர் அடி பின்னுக்கு நகர்ந்து விம்மத் தொடங்கினான். காந்தி வாத்தியார் சொன்ன அறிவுரை இதுதான். 'நீ படிக்கவேண்டும் என்று ஆசைப்பட்டது நல்லது. ஆனால் களவெடுத்ததுதான் பிழை.'

அங்கே நடந்த விசயம் எங்கள் மூவரையும் தவிர வேறு ஒருவருக்கும் தெரியாது. அவர் வெள்ளிக்கிழமைகளில் முழு நாளும் உபவாசம் இருப்பது மாணவர்களுக்கு தெரியும். 'பசிக்காதா சேர், உங்களுக்கு நோய் பிடிக்காதா?' என்று கேட்பார்கள். அவர் சொல்வார், போன சனிக்கிழமையில் இருந்து அடுத்த வெள்ளிக்கிழமை நான் விரதம் என்பது எனக்கு தெரியும். என் வயிற்றுக்கும் தெரியும். அது தன்னைத் தயார் செய்துவிடும். எதிர்பார்ப்புத்தான் பசியைக் கொண்டுவருகிறது. எங்கள் ஊரில் வரும் நோய்களில் பாதிக்குமேல் தண்ணீரால் வருபவை. தண்ணீரைக் காய்ச்சிக் குடியுங்கள், பாதி நோய் போய்விடும் என்பார். அனைத்து மாணவர்களும் வீடுகளில் போய் தங்கள் தாய்மார்களை தொந்திரவு செய்வார்கள். தண்ணீரைச் சுடவைத்தால்தான் குடிப்பேன் என்று அடம் பிடிப்பார்கள். அடுத்தநாள் பெற்றோர்கள் தலைமையாசிரியருக்கு முறைப்பாடு கொண்டுவருவது நிச்சயம்.

காந்தி வாத்தியாருக்கு கடிதம் போட்டு பல வாரங்களாகியும் பதில் இல்லை. அவர் இருப்பது திருக்கோணமலையில். அங்கே நிலவரங்கள் சரியில்லை என்று தமிழ் தினசரிகளில் செய்திகள் வந்த வண்ணம் இருந்தன. ஆள் கடத்தலும் குண்டு வெடிப்புகளும் குறைந்தபாடில்லை. கடிதம் போய்ச் சேர்ந்ததோ என்றுகூடத் தெரியாது. ஒரு பதில் வந்தால் நிம்மதியாக இருக்குமே என்று நினைத்துக்கொண்டேன். ஆறு மாதம் கழித்து காந்தி வாத்தியார்தான் எழுதியிருந்தார். ஒரு 15 வயதுப் பெண்ணின் கையெழுத்துப்போல ஓர் எழுத்தோடு ஒன்று முட்டாமால் வட்ட வட்டமான எழுத்துக்கள்.

'அன்புள்ள ஐயா' என்று கடிதம் தொடங்கியதும் எனக்கு துணுக்கென்றது. நான் என்னை யாரென்று அவருக்கு நினைவூட்டுவதற்காக என் தங்கையைப் பற்றியும், தம்பியைப் பற்றியும், அண்ணனைப்பற்றியும் எழுதியிருந்தேன். நான் அவரிடம் 'சத்திய சோதனை' புத்தகம் பரிசு பெற்றதையும் ஞாபகப்படுத்தியிருந்தேன். 'தங்களுடைய கடிதம் எனக்கு பெரிய மகிழ்ச்சியையும், ஆனந்தத்தையும் தந்தது. அத்தோடு அதிசயமாகவும் இருந்தது. தங்கள் கடிதத்தை என் மனைவிக்கு வாசித்துக் காட்டினேன். அவர் மிகவும் சந்தோசப்பட்டார். இரண்டு நாள் கழித்து அவர் சிவபதம் அடைந்தார். அவருக்கு வயது 84. எனக்கு 90 நடக்கிறது.'

இப்படி தொடர்ந்து அவர் பல விசயங்களை நீலக் கடிதத்தின் ஓர் ஓரத்தில் இருந்து மறு ஓரம் வரை நெருக்கி நெருக்கி, கடிதத்தின் முழுப்பெறுமதியையும் பெறும்விதமாக எழுதியிருந்தார். தான் வெள்ளிக்கிழமைகளில் நீராகாரம் மட்டுமே அருந்துவதாகவும் கடந்த 65 வருடங்களில் ஒரு நாள்கூட அதில் தவறியதில்லை என்றும் எழுதியிருந்தார். நடப்பது கஷ்டமாக இருக்கிறதாம். யாரோவுடைய சைக்கிள் பாரிலும், மோட்டார்சைக்கிள் பின் சீட்டிலும் அமர்ந்து வெளியே பயணம் செய்வதாகவும் தூர இடம் என்றால் ஓட்டோவில் போவதாகவும் கடிதத்தில் கூறியிருந்தார். 'ஒரு நாளில் 24 மணி. ஆறு மணி சாப்பாட்டுக்காக உழைக்கவேண்டும். ஆறு மணி சுயகருமங்கள். ஆறு மணி நித்திரை. ஆறு மணி நாட்டு மக்களுக்கு சேவை.' சனங்களுக்கு சேவை செய்யாத ஒவ்வொரு மணி நேரமும் கடவுளிடமிருந்து தூரமாகவும், மரணத்துக்கு கிட்டவாகவும் தான் நகர்வதை உணருவதாக அவர் சொன்னது நினைவுக்கு வந்தது. அவருடைய இந்தக் கொள்கையில் கடந்த 65 வருடங்களில் ஒரு மாற்றம்கூட இல்லை என்பதையும் எனக்கு தெரிவித்திருந்தார்.

காந்தி வாத்தியார் கடிதத்தை இப்படி முடித்திருந்தார்.

'தாங்கள் மனமுவந்து மன நிறைவோடு அனுப்பிய பணம் வங்கிமூலம் பெற்றுக்கொண்டேன். நீங்கள் உங்களைப் பல வகையிலும், பல நிகழ்ச்சிகளிலும் நினைவூட்டி எழுதி அறிமுகப்படுத்தியிருந்தீர்கள். ஆனால் நீங்கள் யாரென்று எனக்கு ஞாபகமில்லை. என்னை மன்னியுங்கள்.'

ANDAMAN AND NICOBAR ISLANDS

Andaman and Nicobar Islands

A clear history of the Andaman & Nicobar Islands can be had only from a British Survey of these islands conducted in 1777. The Andaman & Nicobar Islands remained the abode of the Negritos and the Mongoloids respectively, who occupied the Islands for centuries. These islands remained secluded from the mainland till the end of the 18th Century when people from the outside world first arrived. The history of these islands could be divided into four broad periods the period of seclusion and piratical disturbances

a) the British regime - a period of foreign intrusion and settlement

b) the Japanese regime

c) and the Post-Independence period.

In the Second Century, the Andaman and Nicobar Islands were located in the maps prepared by the great Greek astronomer, mathematician and geographer, Claudius Ptolemaeus, which possibly is the earliest reference to these islands. The early history of Nicobar is not well known although these islands were familiar to traders in ancient times, the islands being situated close to the trade route to the Far East. Though little is known about Portuguese activities in these islands, it is evident that the Portuguese missionaries started preaching Christianity among the islanders. The Nicobarese language also reflects a few Portuguese words.




The British Regime

The history of the British in the Andaman and Nicobar islands began in 1788 when Lord Cornwallis, the then Governor General of India, thought of colonizing the islands and instructed Lt. Archibald Blair and Lt. R.H.Colebrook of the Royal Navy to Survey the islands and submit a report on their suitability for a British Colony. According to the recommendation of these two officers the first British settlement was founded in 1789 on Chatham Island, near Port Cornwallis (Now Port Blair). After the Great Revolt in 1857, the British Government thought of establishing a penal settlement here. In March 1858, the first penal settlement was established, with 200 prisoners, mostly rebels from the Indian Army.

Initially the convicts were kept in a jail at Viper island, which is about 15 minutes boat ride from Port Blair. The island had a jail, gallows, Kutcheri, Doctor's residence, etc. Subsequently, this Jail was abandoned and the Cellular Jail at Port Blair was constructed. During the time of successive Superintendents, E.H.Man, General Steward, and Col. Cadell, the number of convicts increased and they were subjected to inhuman tortures at the hands of the British jailors. The foundation of the famous Cellular Jail was laid in 1896. The building was completed in 1906. Many changes, both in policy and practice, took place during Colonel Ferrar's time, which, inter alia, included concession to the convicts, mainland visit, etc.

The Japanese Regime

World War II brought another series of changes in the life of the Andamans. During the War, the Japanese occupied Andamans on March 21, 1942 and kept the region under their effective control till October 8,1945. Initially the Japanese behaved cordially towards the locals, but became harsh and suspicious after instances came to their notice of some locals maintaining contacts with the British. As a result a large number of innocent people were killed. One such place where the massacre occured is Humfreygunj. But one good result of the Japanese occupation was making the Andamans self-sufficient, at least in food production. The naval blockade created an acute food crisis and the Japanese compelled the local people to bring more land under cultivation. They also constructed roads.

Netaji Subash Chandra Bose arrived in Port Blair on December 29, 1943 and was given a ceremonial welcome. He hoisted the National Flag at Port Blair on 30th Dec. 1943 for the first time during the British regime in India. On October 8, 1945, the Japanese surrendered to the South East Asia Command at Port Blair. The Government quickly restored normalcy in the area and started rehabilitation work.

The Post Independence Regime

The Andaman and Nicobar Islands together with the rest of India, became Independent on August 15th, 1947. The Bengalis are the major population group which came to the Andamans after Independence. They came as 'settlers' under the Government rehabilitation scheme, which started as early as 1949 and continued till the 1970s. All these groups migrated to the Andamans from different districts of East Pakistan ( now Bangladesh). The Bengalis are primarily distributed in the different villages of North, Middle and South Andamans. The rehabilitated settlers of Great Nicobar are the Ex-servicemen. Ex-servicemen were rehabilitated according to the rules of the District Soldier, Sailor, Airmen Board, formerly known as the Ex-servemen Association and the Indian Ex-servicemen League.

The first batch of Ex-servicemen came to the island in 1969. Others, from different parts of the mainland followed in 1970,1974,1977,1979 and 1980. These settlers include among others, Punjabis, Marathis, Malyalis and Tamilians. New rules and legislation were enacted and a Chief Commissioner directly nominated by the President of India headed the islands. On November 12, 1982, the post of Chief Commissioner was elevated to the rank of Lt. Governor. The Andaman and Nicobar Islands now send one elected representative to the Lok Sabha.

Land AND People

The Andaman and Nicobar Islands were shrouded in mystery for centuries because of their inaccessibility. These are the paragon of beauty and present a landscape full with scenic and picturesque extravaganza. These islands shimmer like emeralds in the Bay of Bengal. The dense forest which cover these islands and the innumerable exotic flowers and birds create a highly poetic and romantic atmosphere. "Here the white beaches on the edge of a meandering coastline have palm trees that sway to the rhythm of the Sea. The beat of tribal drums haunt the stillness and technicolour fish steer their way through crystal clear water." This addition of strangeness to beauty which is responsible for creating the infinite romantic impact may be described in the following famous lines of Keats.

"Charmed magic casement opening on the foam Of perilous seas in fair lands forlorn."

The scenic beauty of Andaman & Nicobar Islands, would create a sense of dissatisfaction and the human mind would rebel against "the whole mass of the motley facts of life". He would be guided by an irresistible desire to this paradise on earth, with invincible faith on the philosophy of Wordsworth:

"Our cheerful faith, that all which we behold is full of blessing".

The Andaman & Nicobar are a group of picturesque Islands, big and small, inhabited and uninhabited, a total of 572 islands, islets and rocks lying in the South Eastern Part of the Bay of Bengal.They lie along an arc in long and narrow broken chain, approximately North-South over a distance nearly 800 kms. . It is logical to presume a former land connection form Cape Negris at South part of Burma to Achin Head (Cape Pedro) in Andalas (Sumatra). The flora and fauna of these islands, however, indicate that this land connection if it existed, should have been prior to the development of their present life form.

There are five Primitive Tribal Groups who have been identified in the Andaman & Nicobar Islands. They are

i) Great Andamanese of Strait Island

ii) Onges of Little Andaman

iii) Jarawas of South and Middle Andaman

iv) Sentinelese of Sentinel Islands, and

v) Shompens of Great Nicobar

(i) The Great Andamanese

They are once the largest in population among the various tribes inhabiting the Andaman Islands. Their estimated population in 1789 was 10,000. By 1901, their number had decreased to 625 and by 1969 their number had decreased to 19 only. According to the Census of 1971, only 24 of them survived, but by 1999. their number has increased to 41. The Administration is doing its best to protect and preserve these tribes. These tribals have been rehabilitated in a small island named Strait Island. The Great Andamanese are foragers.

Today, they eat rice, dal chapati and other modern food articles. They can cook food with the ingredients of spices. At times, they still go in for hunting and gathering. Actually, their traditional food items are fish, dugong, turtle, turtle eggs, crabs, roots and tubers. They also eat pork, Andaman water monitor lizard, etc. As aquatic people, they relish octopus, molluses taken out from shell marine animals like turban shell, scorpion shell, sundial, helmet, trochus and screw shell besides various types of crabs and fish. Some of them cultivate vegetables. Of late, they have established poultry farms. They are exposed to highly communicable diseases besides unhealthy drinking habits which of course are acquired after contact with the monbund urban dominant and advanced communities.

ii) Onge

Onges are one of the most primitive tribes in India. They belong to the Negrito racial stock and they have been relegated to the reserved pockets both at Dugong Creek and South Bay of Little Andaman Island. They are also diminishing in number. They live in a remote corner of the country in a small pocket. They are the semi-nomadic tribes and fully dependent on the food provided by nature. They have now experienced the impact of outsiders. At the same time efforts at befriending them have proved to be successful.

They have been provided with pucca hut type houses, food, clothes, medicines, etc by the Administration. They eat turtle, fish, roots and jack frutis and etc. They have developed artistry and craft. The Onges can make canoes. A primary school has been functioning at the Dugong Creek settlement of Onges. This tribe has become laid back and dependent in their ways. Also their rate of reproduction has become very low.

iii) Jarwas

They are now friendly and voluntary seek medical assistance. They do not have good canoes but can make rafts which they build to cross the streams. The year 1974 was a land mark in the history of Jarawas. Dropping of gifts was done in February and March 1974. After establishing this friendly mission with the Jarawas, the contact party of the Administration quite often met the Jarawas and gave them gift items like banana, coconut and other fruits. With the passage of time, the behavioral pattern of Jarawas have changed. Till the beginning of 1998, they remained hostile, but now they are coming out of the jungle quite often and are becoming friendlier. For nearly a year there is no incidence of killing of villagers by the Jarawas.

On the other hand, the Jarawas are coming out from their habitat to mix with the local people. After giving them gift items like bananas, coconuts, etc,. they are being sent out to live in their own natural habitat, with view not to force them to have a taste of the civilized world. Isolated so long, the Jarawas otherwise appear to be healthy, with smooth skin, deep curly hair, long and sturdy hands and legs and sturdy bones. They are physically fit for hunting, fishing. Unlike, other tribes mention earlier, the Jarawas are not welfare dependent people. As nomadic tribes subsisting on hunting, fishing and gathering activities, their traditional food articles consist of boar (wild boar), turtles and their eggs, crabs and other shore animals, etc. wild pig fruits and honey.

(iv) Sentenlese

The Sentinelese are the inhabitants of North Sentinel Island. The area is about 60 Sq. Kilometers. They are probably the world’s only Paleolithic people surviving today without contact with any other group or community. They are considered as an off-shoot to the Onge Jarawa tribes which have acquired a different identity due to their habitation in an isolated and have lost contact with the main tribes. The Sentinelese are very hostile and never leave their Island. Very little is known about these hostile tribes.

(v) Shompens

The habitation of Shompens is the Great Nicobar which is the largest among the Nicobar group of Islands. Like the Nicobarese, they belong to the Mongoloid race. The Shompens have two divisions, the smaller division being known as Mawa Shompens. They inhabit areas very close to the coastal region along the river valleys. They are very shy. They are quite intimate with the Nicobarese and of the major group of Shompens, the hostile Shompens are living in Alexendra and Galathia river areas and also on the east coast of the area in the interior of the Island. In the past, frequent attacks are believed to have been made on the Mawa Shompens by the hostile Shompens. But now, such hostility has been stopped. It is probably because they have been largely reduced in number due to various diseases. The Mawa Shompens are the victims of diseases and physically very weak. With the establishment of the settlement at Campbell Bay in Great Nicobar, Shompens have been visiting the settlers and they are gradually shaking off their shyness and indifferent attitude towards the civilised people.

PLACES OF INTERESTS

Cellular Jail

Cellular Jail, located at Port Blair, stood mute witness to the tortures meted out to the freedom fighters, who were incarcerated in this Jail. The Jail, completed in the year 1906 acquired the name, ‘cellular’ because it is entirely made up of individual cells for the solitary confinement of the prisoners. It originally was a seven pronged, puce-coloured building with central tower acting as its fulcrum and a massive structure comprising honeycomb like corridors. The building was subsequently damaged and presently three out of the seven prongs are intact. The Jail, now a place of pilgrimage for all freedom loving people, has been declared a National Memorial.

The penal settlement established in Andamans by the British after the First War of Independence in 1857 was the beginning of the agonising story of freedom fighters in the massive and awful jails at Viper Island followed by the Cellular Jail. The patriots who raised their voice against the British Raj were sent to this Jail, where many perished. Netaji Subash Chandra Bose hoisted the tri-colour flag to proclaim Independence on 30th December 1943 at a place near this Jail.

This three-storeyed prison, constructed by Britishers in 1906, is a pilgrimage destination for freedom fighters. This colossal edifice has mutely witnessed the most treacherous of inhumane atrocities borne by the convicts, who were mostly freedom fighters. Now dedicated to the nation as a National Memorial.

Ross Island

Ross Island, the erstwhile capital of Port Blair during the British regime, is a tiny island standing as guard to Port Blair harbour. The island presently houses the ruins of old buildings like Ballroom, Chief Commissioner’s House, Govt. House, Church, Hospital, Bakery, Press, Swimming Pool and Troop Barracks, all in dilapidated condition, reminiscent of the old British regime.

Ever since Dr. James Pattison Walker arrived in Port Blair aboard the East India Company’s steam frigate ‘Senuramis’ on 10th March 1858, this island remained under British occupation till 1942. From 1942 to 1945, the island was under the occupation of Japanese. However, the allies reoccupied the island in 1945 and later abandoned it.


During British occupation, this island was the seat of power of the Britishers. It was developed into self-equipped township with all facilities required for a civilized colony. Dr. Walker, Chairman of the Andaman Committee, established the infamous and the dreaded Penal Settlement with 200 convicts. The Britishers even persuaded the aborigines to come and live in some huts at Ross Island and even established an Andaman Home for them in 1863. Later on the services of these Andamanese were used to catch the escaping convicts from Ross Island.

The island with historical background and preservable ruins is spread along an area of 0.6 sq. kms. With the ruins and also with the historical background, the Island has gained a lot of popularity among the tourists.

Ross island is open for the tourists to visit during day time as the boat services are available from the Phoenix Bay jetty at 8.30 AM, 10.30 AM, and 12.30 PM. Navy has established a museum on the Island Known as ‘Smritika’ depicting the history of the Island.

Viper Island

The tiny, serene, beautiful island of Viper witnessed the untold sufferings the freedom fighters had to undergo. Dangerous convicts found guilty of violating the rules of the Penal Settlement, were put in fetters and were forced to work with their fetters on in this island. Freedom fighters like Nanigopal and Nandlal Pulindas, who had resorted to hunger strike at the Cellular Jail, were imprisoned at Viper Island. The jail at Viper, where prisoners deported from the mainland were confined, was built by the British under the supervision of Major Fort. Work on the prison was started in 1867. Owing to the working conditions, the jail earned the notorious name Viper Chain Gang Jail.

The island derives its name from the vessel ‘Viper’ in which Lt. Archibald Blair came to the islands in 1768 with the purpose of establishing a Penal Settlement. The vessel, it is believed, met with an accident and its wreckage was abandoned near the island.

Gallows built on top of a hillock, visible to all prisoners in the island, signified death. Sher Ali, the Pathan, guilty of murdering Lord Mayo, was condemned to death and hanged at Viper Island.

The Harbour cruise, available daily from Phoenix Bay Jetty (at 3 PM), provides a panoramic view of different points around the harbour and includes a trip to Viper Island.

Neil Island (36 kms. from Port Blair)






This beautiful island with lush green forest and sandy beaches is the vegetable bowl of Andamans. Connected by boat from Port Blair four days a week, it provides an ideal holiday for eco-friendly tourists. Hawabill Nest guesthouse of the Directorate of Tourism is situated here (Tel: 82630). One can feel the sincerity and serenity of village life here. Beautiful beaches at Laxmanpur, Bharatpur, Sitapur and the bridge formation on the sea-shore (Howra bridge) are the attractions.

Long Island (82 kms. from Port Blair)

Connected by boat four times a week from Phoenix Bay Jetty, this island offers an excellent sandy beach at Lalaji Bay, unpolluted environment and evergreen forests. The sea around the island is frequented by dolphin convoys. Lalaji bay, 6 kms. away from the boat jetty, is accessible by 15 minutes journey in dinghies or trekking through the forest. Directorate of Tourism offers island camping during season.

Rangat (170 kms. by road and 90 kms. by sea)

One can enjoy the quiet village life and solitude of virgin nature here. You can also breathe unpolluted air, a rare commodity for the city dweller. Cutbert Bay beach (20 kms. away from Rangat bazar/jetty) is a turtle nesting ground. One can view the nesting of turtles during December – February season. Hawksbill Nest, guest house of the Directorate of Tourism, is near to the Cutbert bay beach and Turtle sanctuary. Panchavati waterfall and Amkunj beach are on the way to Cutbert bay. One can go to Mayabunder and Diglipur from here.

Mayabunder (242 kms. by road/136 kms. by sea)

Situated in the northern part of Middle Andaman, Mayabunder offers excellent scenic beauty and beautiful beaches. Inhabited by the settlers from Burma, East Pakistan and ex-convicts, Mayabunder has a distinct culture. Beach at Avis Island (30 minutes boat journey from Mayabunder), Karmatang beach (13 kms.) and mangrove lined creeks are the attractions. Karmatang beach is also a turtle nesting ground. One can view nesting of turtles during December-February season. Swiftlet Nest guest house of the Directorate of Tourism (Tel: 73495) is very near to the Karmatang beach. One can go to Kalighat (for Diglipur) by boat from here.

Diglipur (290 kms by road/180 kms. by sea)

Situated in North Andaman Island, Diglipur provides a rare experience for eco-friendly tourists. It is famous for its oranges, rice and marine life. Saddle Peak, 732 metres, the highest point in the islands is nearby. Kalpong, the only river of Andaman flows from here. The first hydroelectric project of the islands is coming upon this river. One who comes by road from Port Blair has to take a boat from Mayabunder to Kalighat and from there journey by road to Diglipur (25 kms.), and from there to Kalipur (18 kms.) for viewing, Kalipur and Lamiya bay beaches. Directorate of Tourism provides comfortable accommodation at Turtle Resort, Kalipur. The Water Sports Centre is near by. Those who want to go for trekking to Saddle Peak can collect trekking equipments on hire from Turtle Resort and start trekking from Kalipur. Ram Nagar beach (15 kms. away from Kalighat) is famous for Turtle nesting during December – February season. One who comes by boat from Port Blair will reach Aerial bay jetty, which is very near to places like Diglipur and Kalipur.

Ross and Smith, the twin islands joined by a bewitching sand bar, is 30 minutes away from Aerial bay jetty or Kalipur water sports centre. Directorate of Tourism offers island camping at Smith island during the tourist season. One can feel the innocent beauty of village life everywhere in Diglipur. One who prefers to be away from the hustle and humdrum of urban life must come here to enjoy unhurried holidays. Saddle peak is popular for trekking/nature trail through the evergreen rain forest. Kalighat is connected by daily two boat services from Mayabunder. Port Blair – Diglipur (Aerial bay jetty) boat services are available twice a week.

Little Andaman Island (120 kms. by sea)

This island has a beautiful beach at Butler Bay, a waterfall and plantation of oil palms. Apart from this there are several sandy beaches all along the coastline of the island. The break water at Hut Bay offers an excellent view to the tourists. Little Andaman is the vegetable bowl for the Nicobar group of islands. The Onge tribals live in this island, so do Nicobarese apart from settlers from erstwhile East Pakistan and other places. However entry to tribal areas is restricted. Journey 8 hrs. by sea from Port Blair towards south.

Places of Interest in Nicobar

Comprising of 28 Islands, with an area of 1,841 sq.Kms. the Nicobar Islands are separated from Andamans by the Ten Degree Channel.. The Nicobars abound in coconut-palm, casuarina and pandanus. Great and Little Nicobar have the Giant Robber Crab, Monkeys with long tail, Nicobarese Pigeons in plenty. Megapode, a rare bird is found in Great Nicobar. The southernmost tip of India is not Kanyakumari as has till recently been considered, it is INDIRA POINT in Great Nicobar Island. Nicobar group is out of bounds for foreigners at present. Indians may be given permission in exceptional cases on application.

Car Nicobar: (Area 126.9 sq. km., Distance 270 kms. by sea)

A rustling fan, Car Nicobar is the headquarters of Nicobar District. It is a flat fertile island covered with cluster of coconut palms and enchanting beaches with a roaring sea all around. The Nicobari huts, built on stilts having entrance through floor with a wooden, ladder, are unique to this island. 16 hrs. journey by sea from Port Blair.

Katchal (425 kms. by sea)

Katchal is a tiny island in the Nicobar group. It was this island, which heralded the new millennium with the first sunrise on 1st January 2000. This island has beautiful beaches at East bay, Jhula and West bay.

Great Nicobar (540 kms. by sea)

The southern end of the Nicobars, this island has Indira Point (formerly Pygmallion Point) the southern most tip of India. The beach near Galathia is the nesting ground for Gaint Leather Back Turtles. This island also has biosphere reserve area. 50-60 hrs. journey by sea from Port Blai

Tuesday, January 12, 2010

ENGINEERING PHYSICS-II




AUTHORS: Dr.D.JAYARAMAN, Dr.K.ILANGOVAN & B.BALAKRISHNAN
PUBLIHSER: ANURADHA PUBLICATOINS, KUMBAKONAN & CHENNAI


Chapter I Conducting materials

Conductor-classical free electron theory of metals-electrical and thermal conductivity-Wiedmann Franz law-Lorentz number- draw backs of classical theory-quantum theory-Fermi distribution theory- effect of temperature on Fermi function-density of energy states-carrier concentration in metals.

Chapter II Semiconducting materials

Intrinsic semiconductor- carrier concentration derivation-Fermi level- variation of Fermi level with temperature-electrical conductivity-band gap determination-extrinsic semiconductor – carrier concentration derivation in n-type and p-type semiconductor-variation of Fermi level with temperature and impurity concentration-compound semiconductor-Hall effect-determination of Hall coefficient-applications

Chatper III Magnetic materials

Origin of magnetic moment-Bohr magneton-dia and para magnetism-Ferro mangnetism-domain theory –hysteresis-soft and hard magnetic materials-antiferro magnetic materials-ferrites-applications-magnetic recording and readout-storage of magnetic data-tapes-floppy and magnetic disc drives.

Chapter IV Superconducting materials

Superconductivity-properties-types of superconductors-BCS theory of superconductivity-(qualitative)-High temperature superconductors- applications of superconductor-SQUID- cryotron-magnetic levitation

Chapter V Dielectric materials

Electrical susceptibility-dielectric constant-electronic-ionic, orientational and space charge polarization-frequency and temperature dependence of polarization-internal field-Clausius-Mosotti relation derivation-dielectric loss-dielectric breakdown-uses of dielectric materials- (capacitor and transformer)-ferroelectricity and application

Chapter VI Modern engineering materials-I

Metallic glasses preparation, properties and applications- shape memory alloys (SMA)-Characteristic properties of NiTi alloy-application-advantages and disadvantages of SMA.

Chapter VII Modern engineering materials-II

Nanometerials-synthesis-plasma arcing-chemical vapour deposition- solgels-electrodeposition- ball milling- properties of nanoparticles and applications-carbon nanotubes fabrication-arc method- pulsed laser deposition-chemical vapour deposition-structure-properties and applications.

An interesting short story

"அப்படி என்னதான் வேலை பார்ப்பீங்க ?" நியாயமான ஒரு கேள்வி!


"ஏம்பா இந்த கம்ப்யூட்டர் படிச்சவங்க எல்லாம் நிறைய சம்பளம் வாங்கிட்டு, பந்தா பண்ணிட்டு ஒரு தினுசாவே அலையுறீங்களே? அப்படி என்னதான் வேலை பார்ப்பீங்க ?" நியாயமான ஒரு கேள்வியை கேட்டார் எனது அப்பா.

நானும் விவரிக்க ஆரம்பிதேன்.

"வெள்ளைகாரனுக்கு எல்லா வேலையும் சீக்கிரமா முடியனும். அதே மாதிரி எல்லா வேலையும் அவனோட வீட்டுல இருந்தே செய்யணும். இதுக்காக எவ்வளவு பணம் வேணுமானாலும் செலவு செய்ய தயாரா இருக்கான்."

"அது சரி, பல்லு இருக்குறவன் பக்கோடா சாப்பிடுறான்".

"இந்த மாதிரி அமெரிக்கால்-ல, இங்கிலாந்து-ல இருக்குற Bank, இல்ல எதாவது கம்பெனி, 'நான் செலவு செய்ய தயாரா இருக்கேன். எனக்கு இத செய்து கொடுங்கன்னு கேப்பாங்க' - இவங்கள நாங்க "Client"னு சொல்லுவோம்"

"சரி"

இந்த மாதிரி Client-அ மோப்பம் பிடிக்குறதுக்காகவே எங்க பங்காளிக கொஞ்ச பேர அந்த அந்த ஊருல உக்கார வச்சி இருப்போம். இவங்க பேரு "Sales Consultants, Pre-Sales Consultants....". இவங்க போய் Client கிட்ட பேச்சுவார்த்தை நடத்துவாங்க. காசு கொடுகுறவன் சும்மாவா கொடுப்பான்? ஆயிரத்தெட்டு கேள்வி கேப்பான். உங்களால இத பண்ண முடியுமா? அத பண்ண முடியுமான்னு அவங்க கேக்குற எல்லாம் கேள்விக்கும், "முடியும்"னு பதில் சொல்றது இவங்க வேலை."

"இவங்க எல்லாம் என்னப்பா படிச்சுருபாங்க"?

"MBA, MSனு பெரிய பெரிய படிபெல்லாம் படிச்சி இருப்பாங்க."

"முடியும்னு ஒரே வார்த்தைய திரும்ப திரும்ப சொல்றதுக்கு எதுக்கு MBA படிக்கணும்?" அப்பாவின் கேள்வியில் நியாயம் இருந்தது. "சரி இவங்க போய் பேசின உடனே client project கொடுத்துடுவானா?"

"அது எப்படி? இந்த மாதிரி பங்காளிக எல்லா கம்பெனிளையும் இருப்பாங்க. 500 நாள்ல முடிக்க வேண்டிய வேலைய 60 நாள்ள முடிச்சு தரோம், 50 நாள்ல முடிச்சு தரோம்னு பேரம் பேசுவாங்க. இதுல யாரு குறைஞ்ச நாள சொல்றாங்களோ அவங்களுக்கு ப்ராஜெக்ட் கிடைக்கும்"

"500 நாள்ல முடிக்க வேண்டிய வேலைய 50 நாள்ல எப்படி முடிக்க முடியும்? ராத்திரி பகலா வேலை பார்த்தாலும் முடிக்க முடியாதே?"

"இங்க தான் நம்ம புத்திசாலித்தனத்த நீங்க புரிஞ்சிக்கணும். 50 நாள்னு சொன்ன உடனே client சரின்னு சொல்லிடுவான். ஆனா அந்த 50 நாள்ல அவனுக்கு என்ன வேணும்னு அவனுக்கும் தெரியாது, என்ன செய்யனும்னு நமக்கும் தெரியாது. இருந்தாலும் 50 நாள் முடிஞ்ச பிறகு ப்ரோஜெக்ட்னு ஒன்ன நாங்க deliver பண்ணுவோம். அத பாத்துட்டு "ஐய்யோ நாங்க கேட்டது இதுல்ல, எங்களுக்கு இது வேணும், அது வேணும்னு" புலம்ப ஆரம்பிப்பான்.

"அப்புறம்?" - அப்பா ஆர்வமானார்.

"இப்போ தான் நாங்க நம்பியார் மாதிரி கைய பிசஞ்சிகிட்டே "இதுக்கு நாங்க CR raise பண்ணுவோம்"னு சொல்லுவோம்.

"CR-னா?"

"Change Request. இது வரைக்கும் நீ கொடுத்த பணத்துக்கு நாங்க வேலை பார்த்துட்டோம். இனிமேல் எதாவது பண்ணனும்னா எக்ஸ்ட்ரா பணம் கொடுக்கணும்"னு சொல்லுவோம். இப்படியே 50 நாள் வேலைய 500 நாள் ஆக்கிடுவோம்."

அப்பாவின் முகத்தில் லேசான பயம் தெரிந்தது. "இதுக்கு அவன் ஒத்துபானா?"

"ஒத்துகிட்டு தான் ஆகணும்.. முடி வெட்ட போய்ட்டு, பாதி வெட்டிட்டு வர முடியுமா?"

"சரி ப்ராஜெக்ட் உங்க கைல வந்த உடனே என்ன பண்ணுவீங்க?"

"முதல்ல ஒரு டீம் உருவாக்குவோம். இதுல ப்ராஜக்ட் மேனேஜர்னு ஒருத்தர் இருப்பாரு. இவரது தான் பெரிய தலை. 'ப்ராஜெக்ட்' சக்சஸ் ஆனாலும், 'பெயிலியர் ' ஆனாலும் இவரு தான் பொறுப்பு."

"அப்போ இவருக்கு நீங்க எல்லாரும் பண்ற வேலை எல்லாம் தெரியும்னு சொல்லு."

"அதான் கிடையாது. இவருக்கு நாங்க பண்ற எதுவும்யே தெரியாது."

"அப்போ இவருக்கு என்னதான் வேலை?" அப்பா குழம்பினார்.

"நாங்க என்ன தப்பு பண்ணினாலும் இவர பார்த்து கைய நீட்டுவோம். எப்போ எவன் குழி பறிப்பானு 'டென்ஷன்' ஆகி, 'டயர்ட்' ஆகி, 'டென்ஷன்' ஆகுறது தான் இவரு வேலை.."

"பாவம்பா"

"ஆனா இவரு ரொம்ப நல்லவரு. எங்களுக்கு எந்த பிரச்னை வந்தாலும் இவரு கிட்ட போய் சொல்லலாம்."

"எல்லா பிரச்னையும் தீர்த்து வச்சிடுவார?"

"ஒரு பிரச்சனைய கூட தீர்க்க மாட்டாரு. நாங்க என்ன சொன்னாலும் தலையாட்டிகிட்டே உன்னோட பிரச்னை எனக்கு புரியுதுனு சொல்றது மட்டும் தான் இவரோட வேலை."

"நான் உன்னோட அம்மா கிட்ட பண்றத மாதிரி?!"

"இவருக்கு கீழ டெக் லீட், மோடுல் லீட், டெவலப்பர், டெஸ்டர்னு நிறைய அடி பொடிங்க இருப்பாங்க."

"இத்தனை பேரு இருந்து, எல்லாரும் ஒழுங்கா வேலை செஞ்சா வேலை ஈஸியா முடிஞ்சிடுமே?"

"வேலை செஞ்சா தானே? நான் கடைசியா சொன்னேன் பாருங்க... டெவலப்பர், டெஸ்டர்னு, அவங்க மட்டும் தான் எல்லா வேலையும் செய்வாங்க. அதுலையும் இந்த டெவலப்பர்,வேலைக்கு சேரும் போதே "இந்த குடும்பத்தோட மானம், மரியாதை உன்கிட்ட தான் இருக்குனு" சொல்லி, நெத்தில திருநீறு பூசி அனுப்பி வச்ச என்னைய மாதிரி தமிழ் பசங்க தான் அதிகம் இருப்பாங்க."

"அந்த டெஸ்டர்னு எதோ சொன்னியே? அவங்களுக்கு என்னப்பா வேலை?"

"இந்த டெவலப்பர் பண்ற வேலைல குறை கண்டு பிடிக்கறது இவனோட வேலை. புடிக்காத மருமக கை பட்டா குத்தம், கால் பட்டா குத்தம் இங்குறது மாதிரி."

"ஒருத்தன் பண்ற வேலைல குறை கண்டு பிடிகுறதுக்கு சம்பளமா? புதுசா தான் இருக்கு. சரி இவங்களாவது வேலை செய்யுராங்களா. சொன்ன தேதிக்கு வேலைய முடிச்சு கொடுத்துடுவீங்கள்ள?"

"அது எப்படி..? சொன்ன தேதிக்கு ப்ராஜக்டை முடிச்சி கொடுத்தா, அந்தக் குற்ற உணர்ச்சி எங்க வாழ்கை முழுவதும் உறுத்திக்கிட்டு இருக்கும். நிறைய பேரு அந்த அவமானத்துக்கு பதிலா தற்கொலை செய்துக்கலாம்னு சொல்லுவாங்க"

"கிளையன்ட், சும்மாவா விடுவான்? ஏன் லேட்னு கேள்வி கேக்க மாட்டான்?"

"கேக்கத்தான் செய்வான். இது வரைக்கும் டீமுக்குள்ளையே காலை வாரி விட்டுக்கிட்டு இருந்த நாங்க எல்லாரும் சேர்ந்து அவன் காலை வார ஆரம்பிப்போம்."

"எப்படி?"

"நீ கொடுத்த கம்ப்யூட்டர்-ல ஒரே தூசியா இருந்துச்சு. அன்னைக்கு டீம் மீட்டிங்ல வச்சி நீ இருமின, உன்னோட ஹேர் ஸ்டைல் எனக்கு புடிகலை." இப்படி எதாவது சொல்லி அவன குழப்புவோம். அவனும் சரி சனியன எடுத்து தோள்ல போட்டாச்சு, இன்னும் கொஞ்ச நாள் தூங்கிட்டு போகட்டும்னு விட்டுருவான்".

"சரி முன்ன பின்ன ஆனாலும் முடிச்சி கொடுத்துட்டு கைய கழுவிட்டு வந்துடுவீங்க அப்படித்தான?"

"அப்படி பண்ணினா, நம்ம நாட்டுல பாதி பேரு வேலை இல்லாம தான் இருக்கணும்."

"அப்புறம்?"

"ப்ராஜக்டை முடிய போற சமயத்துல நாங்க எதோ பயங்கரமான ஒன்ன பண்ணி இருக்குறமாதிரியும், அவனால அத புரிஞ்சிக்க கூட முடியாதுங்கற மாதிரியும் நடிக்க ஆரம்பிப்போம்."

"அப்புறம்?"

"அவனே பயந்து போய், "எங்கள தனியா விட்டுடாதீங்க. உங்க டீம்-ல ஒரு ஒன்னு, ரெண்டு பேர உங்க ப்ரொஜெக்ட பார்த்துக்க சொல்லுங்கன்னு" புது பொண்ணு மாதிரி புலம்ப ஆரம்பிச்சிடுவாங்க. இதுக்கு பேரு "Maintenance and Support". இந்த வேலை வருஷ கணக்கா போகும். ப்ராஜக்ட் அப்படிங்கறது ஒரு பொண்ண கல்யாணம் பண்ணி வீட்டுக்கு கூட்டிட்டு வர்றது மாதிரி. தாலி கட்டினா மட்டும் போதாது, வருஷ கணக்கா நிறைய செலவு செஞ்சு பராமரிக்க வேண்டிய விசயம்னு இப்போ தான் கிளைன்டுக்கு புரிய ஆரம்பிக்கும்".

"எனக்கும் எல்லாம் புரிஞ்சிடுப்பா."