GREATEST MATHEMATICIANS TO WORLD BY US

Great & Famous Mathematicians of India

Aryabhata (475 A.D. -550 A.D.) is the first well known Indian mathematician. Born in Kerala, he completed his studies at the university of Nalanda. In the section Ganita (calculations) of his astronomical treatise Aryabhatiya (499 A.D.), he made the fundamental advance in finding the lengths of chords of circles, by using the half chord rather than the full chord method used by Greeks. He gave the value of as 3.1416, claiming, for the first time, that it was an approximation. (He gave it in the form that the approximate circumference of a circle of diameter 20000 is 62832.) He also gave methods for extracting square roots, summing arithmetic series, solving indeterminate equations of the type ax -by = c, and also gave what later came to be known as the table of Sines. He also wrote a text book for astronomical calculations, Aryabhatasiddhanta. Even today, this data is used in preparing Hindu calendars (Panchangs). In recognition to his contributions to astronomy and mathematics, India's first satellite was named Aryabhata.
Brahmagupta (598 A.D. -665 A.D.) is renowned for introduction of negative numbers and operations on zero into arithmetic. His main work was Brahmasphutasiddhanta, which was a corrected version of old astronomical treatise Brahmasiddhanta. This work was later translated into Arabic as Sind Hind. He formulated the rule of three and proposed rules for the solution of quadratic and simultaneous equations. He gave the formula for the area of a cyclic quadrilateral as where s is the semi perimeter. He was the first mathematician to treat algebra and arithmetic as two different branches of mathematics. He gave the solution of the indeterminate equation Nx²+1 = y². He is also the founder of the branch of higher mathematics known as "Numerical Analysis".
After Brahmagupta, the mathematician of some consequence was Sridhara, who wrote Patiganita Sara, a book on algebra, in 750 A.D. Even Bhaskara refers to his works. After Sridhara, the most celebrated mathematician was Mahaviracharaya or.....
Mahavira. He wrote Ganita Sara Sangraha in 850 A.D., which is the first text book on arithmetic in present day form. He is the only Indian mathematician who has briefly referred to the ellipse (which he called Ayatvrit). The Greeks, by contrast, had studied conic sections in great detail.
Bhaskara (1114 A.D. -1185 A.D.) or Bhaskaracharaya is the most well known ancient Indian mathematician. He was born in 1114 A.D. at Bijjada Bida (Bijapur, Karnataka) in the Sahyadari Hills. He was the first to declare that any number divided by zero is infinity and that the sum of any number and infinity is also infinity. He is famous for his book Siddhanta Siromani (1150 A.D.). It is divided into four sections -Leelavati (a book on arithmetic), Bijaganita (algebra), Goladhayaya (chapter on sphere -celestial globe), and Grahaganita (mathematics of the planets). Leelavati contains many interesting problems and was a very popular text book. Bhaskara introduced chakrawal, or the cyclic method, to solve algebraic equations. Six centuries later, European mathematicians like Galois, Euler and Lagrange rediscovered this method and called it "inverse cyclic". Bhaskara can also be called the founder of differential calculus. He gave an example of what is now called "differential coefficient" and the basic idea of what is now called "Rolle's theorem". Unfortunately, later Indian mathematicians did not take any notice of this. Five centuries later, Newton and Leibniz developed this subject. As an astronomer, Bhaskara is renowned for his concept of Tatkalikagati (instantaneous motion).
After this period, India was repeatedly raided by muslims and other rulers and there was a lull in scientific research. Industrial revolution and Renaissance passed India by. Before Ramanujan, the only noteworthy mathematician was Sawai Jai Singh II, who founded the present city of Jaipur in 1727 A.D. This Hindu king was a great patron of mathematicians and astronomers. He is known for building observatories (Jantar Mantar) at Delhi, Jaipur, Ujjain, Varanasi and Mathura. Among the instruments he designed himself are Samrat Yantra, Ram Yantra and Jai Parkash.

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Famous Indian mathematicians of the 20^th century:
Srinivasa Aaiyangar Ramanujan is undoubtedly the most celebrated Indian Mathematical genius. He was born in a poor family at Erode in Tamil Nadu on December 22, 1887. Largely self taught, he feasted on Loney's Trigonometry at the age of 13, and at the age of 15, his senior friends gave him Synopsis of Elementary Results in Pure and Applied Mathematics by George Carr. He used to write his ideas and results on loose sheets. His three filled notebooks are now famous as Ramanujan's Frayed Notebooks. Though he had no qualifying degree, the University of Madras granted him a monthly scholarship of Rs. 75 in 1913. A few months earlier, he had sent a letter to great mathematician G.H. Hardy, in which he mentioned 120 theorems and formulae. Hardy and his colleague at Cambridge University, J.E. Littlewood immediately recognised his genius. Ramanujan sailed for Britain on March 17, 1914. Between 1914 and 1917, Ramanujan published 21 papers, some in collaboration with Hardy. His achievements include Hardy-Ramanujan-Littlewoo d circle method in number theory, Roger-Ramanujan's identities in partition of numbers, work on algebra of inequalities, elliptic functions, continued fractions, partial sums and products of hypergeometric series, etc. He was the second Indian to be elected Fellow of the Royal Society in February, 1918. Later that year, he became the first Indian to be elected Fellow of Trinity College, Cambridge. Ramanujan had an intimate familiarity with numbers. During an illness in England, Hardy visited Ramanujan in the hospital. When Hardy remarked that he had taken taxi number 1729, a singularly unexceptional number, Ramanujan immediately responded that this number was actually quite remarkable: it is the smallest integer that can be represented in two ways by the sum of two cubes: 1729=1³+12³=9³+10³.
Unfortunately, Ramanujan's health deteriorated due to tuberculosis, and he returnted to India in 1919. He died in Madras on April 26, 1920.
P.C. Mahalanobis : He founded the Indian Statistical Research Institute in Calcutta. In 1958, he started the National Sample Surveys which gained international fame. He died in 1972 at the age of 79.
C.R. Rao : A well known statistician, famous for his "theory of estimation"(1945). His formulae and theory include "Cramer -Rao inequality", "Fischer -Rao theorem" and "Rao - Blackwellisation".
D.R. Kaprekar (1905-1988) : Fond of numbers. Well known for "Kaprekar Constant" 6174. Take any four digit number in which all digits are not alike. Arrange its digits in descending order and subtract from it the number formed by arranging the digits in ascending order. If this process is repeated with reminders, ultimately number 6174 is obtained, which then generates itself.
Harish Chandra (1923-1983) : Greatly developed the branch of higher mathematics known as the infinite dimensional group representation theory.
Narendra Karmarkar : India born Narendra Karmarkar, working at Bell Labs USA, stunned the world in 1984 with his new algorithm to solve linear programming problems. This made the complex calculations much faster, and had immediate applications in airports, warehouses, communication networks etc.


ALL TIME GREAT MATHEMATICIANS AS KNOWN TO WORLD NOW

Isaac Newton Carl F. Gauss Archimedes Leonhard Euler Euclid		Bernhard Riemann Henri Poincaré David Hilbert Joseph-Louis Lagrange Gottfried W. Leibniz		Alexander Grothendieck Pierre de Fermat Niels Abel Évariste Galois John von Neumann
Srinivasa Ramanujan Karl W. T. Weierstrass Brahmagupta René Déscartes Augustin Cauchy		Hermann K. H. Weyl Leonardo `Fibonacci' Carl G. J. Jacobi Peter G. L. Dirichlet Georg Cantor		Arthur Cayley Emma Noether Eudoxus of Cnidus Muhammed al-Khowârizmi Pythagoras of Samos
Kurt Gödel Bháscara Áchárya Blaise Pascal Apollonius of Perga Pierre-Simon Laplace		William R. Hamilton Richard Dedekind Charles Hermite André Weil Stefan Banach		Felix Christian Klein Diophantus of Alexandria George Boole François Viète Ferdinand Eisenstein
Andrey N. Kolmogorov Alhazen ibn al-Haytham Jean le Rond d'Alembert Christiaan Huygens Girolamo Cardano		Pappus of Alexandria Gaspard Monge Johannes Kepler Jacques Hadamard Hipparchus of Nicaea		Jean-Victor Poncelet Siméon-Denis Poisson Jacob Bernoulli Albert Einstein John Wallis
Liu Hui Aryabhatta Godfrey H. Hardy Joseph Liouville L.E.J. Brouwer		Adrien M. Legendre Joseph Fourier John E. Littlewood Élie Cartan Johann Bernoulli		James J. Sylvester Jakob Steiner F.E.J. Émile Borel Archytas of Tarentum Omar al-Khayyám
I probably should have stopped the List at 60 or 70 names, but it's fun to keep expanding. If I were to grow the list even further here are some of the prime candidates:
Michael F. Atiyah M. E. Camille Jordan Henri Léon Lebesgue Takakazu Seki Julius Plücker Francesco B. Cavalieri Alexis C. Clairaut Pafnuti Chebyshev		Aristotle Thales of Miletus Hermann G. Grassmann Galileo Galilei Johann H. Lambert Emil Artin Hermann Minkowski Giuseppe Peano		Hippocrates of Chios Jean-Pierre Serre John Napier of Merchiston Gerard Desargues Paul Erdös J. Gaston Darboux Daniel Bernoulli Madhava of Kerala

INDIAN MATHEMATICS

INDIA ORIGIN OF MATHEMATICS

Indian mathematicians have great contributions and that dates back to Indus Valley Civilization and Veda. Indian mathematicians are known for their important contributions in the field of mathematics that includes concepts like concept of zero and place-value arithmetical notation. Some of the renowned Indian mathematicians during the early Vedic Age include names like Apastamba, Katyayana, Manava, Yajnavalkya, Baudhayana and Panini. Renowned mathematician Baudhayana was also a priest and a noted author. Apastamba`s `Dharmasutra` constitutes a part of the superior Kalpasutra that contains around 30 prasnas, (literally means `questions`). In Dharmasutra, the subjects are well organised and interestingly they are conserved in good condition.

From the classical age, Aryabhata I is one of the most popular and actually the first one in the list of Indian mathematicians-astronomers. He has contributed significantly in the field of mathematics. The most well-known works of Aryabhata include `Aryabhatiya` and `Arya-Siddhanta`. Bhaskara I was a renowned 7th century Indian mathematician. He is the first one to write numbers in Hindu-Arabic decimal system, and who gave a unique and remarkable rational approximation of the sine function in his interpretation on Aryabhata`s work. Jayadeva was a popular Indian mathematician of ninth century. He mainly worked on chakravala method or cyclic method. Further, he also made some significant offerings to combinatory. Brahmagupta was also a popular mathematician of the early age. In Brahmagupta`s work `Pell`s equation` was of prime importance. Bhaskaracharya was also a notable mathematician of the early age and his work had given an algorithmic approach. Mahavira from south India was a prominent mathematician of the 9th century. His work had given special emphasis on problems related to quadratic and cubic equations. In fact his contribution played a prominent role in the development of mathematics in south India. Madhava was also a prominent mathematician of 14th century and his works included detection of elements that are related to differential calculus. He had also given an approximation of pie. Moreover, Madhava had started a school of mathematics in the state of Kerala and some notable followers of that school were Nilakantha and Jyesthadeva. Gopala was also one of the well-known Indian mathematicians.

Some of the famous Indian mathematicians of the later age are S. Ramanujan, A. A. Krishnaswami Ayyangar, P. C Mahalanobis, D. K. Ray-Chaudhuri, Harish-Chandra, Calyampudi Radhakrishna Rao, Shreeram Shankar Abhyankar, Ramdas Lotu Bhirud, Jayant Narlikar, Manjul Bhargava and many others. In all probability S.Ramanujam is most famous amongst the modern mathematician of India. He had produced wonderful results in the number theory but his most famous discovery in the field of mathematics arithmetic theory of modular forms. In a paper which he had presented in 1916 a paper in which he had initiated the study of pie function.

Manjul Bhargava, another noted mathematician of the modern era is known for composing the law for ternary quadratic forms. The work of Manjul Bhargava bears a deep approach and serves as a mathematical guidance. Harish Chandra on the other hand was not a much famous mathematician but his work had formed the base of Langlands`s concept of automorphic forms that are an enormous simplification of the modular forms.


INDIAN MATHEMATICS

Indian mathematicians have great contributions and that dates back to Indus Valley Civilization and Veda. Indian mathematicians are known for their important contributions in the field of mathematics that includes concepts like concept of zero and place-value arithmetical notation. Some of the renowned Indian mathematicians during the early Vedic Age include names like Apastamba, Katyayana, Manava, Yajnavalkya, Baudhayana and Panini. Renowned mathematician Baudhayana was also a priest and a noted author. Apastamba`s `Dharmasutra` constitutes a part of the superior Kalpasutra that contains around 30 prasnas, (literally means `questions`). In Dharmasutra, the subjects are well organised and interestingly they are conserved in good condition.

From the classical age, Aryabhata I is one of the most popular and actually the first one in the list of Indian mathematicians-astronomers. He has contributed significantly in the field of mathematics. The most well-known works of Aryabhata include `Aryabhatiya` and `Arya-Siddhanta`. Bhaskara I was a renowned 7th century Indian mathematician. He is the first one to write numbers in Hindu-Arabic decimal system, and who gave a unique and remarkable rational approximation of the sine function in his interpretation on Aryabhata`s work. Jayadeva was a popular Indian mathematician of ninth century. He mainly worked on chakravala method or cyclic method. Further, he also made some significant offerings to combinatory. Brahmagupta was also a popular mathematician of the early age. In Brahmagupta`s work `Pell`s equation` was of prime importance. Bhaskaracharya was also a notable mathematician of the early age and his work had given an algorithmic approach. Mahavira from south India was a prominent mathematician of the 9th century. His work had given special emphasis on problems related to quadratic and cubic equations. In fact his contribution played a prominent role in the development of mathematics in south India. Madhava was also a prominent mathematician of 14th century and his works included detection of elements that are related to differential calculus. He had also given an approximation of pie. Moreover, Madhava had started a school of mathematics in the state of Kerala and some notable followers of that school were Nilakantha and Jyesthadeva. Gopala was also one of the well-known Indian mathematicians.

Some of the famous Indian mathematicians of the later age are S. Ramanujan, A. A. Krishnaswami Ayyangar, P. C Mahalanobis, D. K. Ray-Chaudhuri, Harish-Chandra, Calyampudi Radhakrishna Rao, Shreeram Shankar Abhyankar, Ramdas Lotu Bhirud, Jayant Narlikar, Manjul Bhargava and many others. In all probability S.Ramanujam is most famous amongst the modern mathematician of India. He had produced wonderful results in the number theory but his most famous discovery in the field of mathematics arithmetic theory of modular forms. In a paper which he had presented in 1916 a paper in which he had initiated the study of pie function.

Manjul Bhargava, another noted mathematician of the modern era is known for composing the law for ternary quadratic forms. The work of Manjul Bhargava bears a deep approach and serves as a mathematical guidance. Harish Chandra on the other hand was not a much famous mathematician but his work had formed the base of Langlands`s concept of automorphic forms that are an enormous simplification of the modular forms.

TOP 10 NATIONS

THE PREVIOUS GIVEN POST  GIVES THE WORLD MOST POWERFUL NATIONS ON THE BASIS OF MILITARY , THE FOLLOWING ONE GIVES TOP TEN NATIONS OF THE WORLD INCLUDING EVERY THING TO TAKE IN ACCOUNT

     My list of the Top 10 in terms of power. 2010

1 The United States of America,

The world's biggest economy and by far in terms of spending and power the worlds strongest army, the most powerful democracy, and the media centre of the world, plus in many ways the centre of world diplomacy and foreign relations. This easily makes the USA the worlds most powerful country. 

2 Peoples Republic of China

Massively importantly in terms of power is the number of people a land rules over, the Middle Kingdom has the largest population on Earth. Additionally like the other top 5 on this list, it is a UN Security council member. It also has established itself as of having nukes, a huge army, and is becoming even more of a international power, as of a resource hungry booming economy. Since the global recession affected Japan more, China has now got the world's 2nd largest GNP ( when canceling out misleading totals for currency values, China placed second in GNP even before the recession, but that PPP measure was not as key to world concerns as the measure made when using exchange rates). A momentous achievement for a fairly recent riser in GNP above France and Britain. Before it's economy became larger than that of Japan, it was still 3rd on this list as of other advantages (I made the change in February 2010, the list started in January 2007), but this new 2nd place will surely make nations even more desperate to appeal to China's wealth, and so power. Also this gives China technological advantages via investment ability. The lack of democracy, harms the legitimacy of it's leaders statements though, when speaking of the wider world. 

3 Russian Federation

The second largest army, and a puppeteer of many Central Asian states. The largest European population, and largest world area, which gives it immense control over itself, and immense levels of independence. The size of Russia helps give it extra resources and abilities that make it such a big power. Russia like the USA has enough Nuclear Weapons to essentially destroy the Earth, while China, France and Britain just have enough to destroy Russia, or the USA. The nuclear option is vital to rankings here, but that is discounted somewhat by the way how they are such a last resort weapon, like how their usage could bring attacks, even devastating ones, from other nations. Russia's economy is a half to a quarter the size of China's at the moment, which means it is more important economically than it was in the mid 1990s, but it is unlikely it could become the world's second largest economy as it was for a while when leading the even larger USSR.

4 France 

The fifth republic has UN security council membership, is a nuclear power and has alot of influence over Africa. It is also a G7 / G8 / G20 economy, is a leading democracy, and has a quite large army, one of worlds most powerful infact. Added to this EU membership gives it extra power, and helps make it's borders, and region peaceful and stable. France also seems more able to act on it's own accord than Britain.

5 Britain

UN security council status, nuclear weapons, G7 economy, a leading democratic state, and a media centre from music to acting, that has alot of influence over the world, especially the English speaking world, as of it's popularity. Membership of the EU adds to it's power. 

6 Japan

The State of Japan has the third largest economy in the world, it's move from 3rd to 2nd, gave China the prestige I feel to be placed 2nd on the world power list. Japan is a big democracy with a large population, giving it big status, but is rammed in by China, and the USA, so is below France, and Britain, who each have stronger international alliances.

7 Republic of India

The most populous democracy, a growing economy, and nuke weapons, as the Second most populous country on Earth it has much moral sway,

8 Federal Republic of Germany

The World's fourth economy, and a top 3 in terms of power of EU members in the 27 European Union countries zone, but hampered in influence, as of World War two, and World War One, Which affected Germany's moral position in the world, and reduced German influence on many areas of the world,

9 Republic of Pakistan

Second largest Muslim country, largest in the area where most Muslim lands are, has nuclear weapons, and a quite united nationality, in terms of identity,

Beats Indonesia, as that land is to far away from other Muslim lands so carries less weight, but it mabye could rise if Pakistan fizzles a bit as of spending so much on it's prior millitary dictatorship their military powerbase. While Indonesia, grows as a more civil democratic land. Maybe Indonesia is below, as it was a even more brutal dictatorship to it's people, in the late 1960s too 1990s. While Pakistan was to other nationalities, such as Bangladeshis, during the 1970s, but to West Pakistan people was not as bad as Indonesia's brutal dictators were to it's people in the mid and late 1960s, If Pakistan had not been so bad to Bengalis then it would still have them, and stand no chance of falling behind Indonesia, as it rises. It's power tussles with India, make it keep a high arms budget, but could weaken it long term, as army spending long term is a inefficient use of economic resources.

10 Republic of Brazil

Largest Latin American country in population and area, Largest Portugueese speaking land, good relations globally,

POWERFUL MILITARY NATIONS

AS PER MY COLLECTION  THE MOST POWERFUL COUNTRIES IN TERMS OF MILITARY RANKED AS FOLLOWS  CLICK ON THE IMAGE TO KNOW THAT COUNTRY MILITARY POWER

COMPARE  TWO COUNTRIES  CLICK HERE
             POWER FULL NATIONS AS FOLLOWS 

1		U.S.A.
2		China
3		Russia
4		India
5		U.K.
6		France
7		Germany
8		Brazil
9		Japan
10		Turkey

11		Israel
12		South Korea
13		Italy
14		Indonesia
15		Pakistan
16		Taiwan
17		Egypt
18		Iran
19		Mexico
20		North Korea

                                  

21		Sweden
22		Greece
23		Canada
24		Saudi Arabia
25		Ukraine
26		Australia
27		Spain
28		Thailand
29		Denmark
30		Poland

COMPUTER VS HUMAN BRAIN

10 MAJOR DIFFERENCES COMPUTER Vs. BRAIN

 

"A good metaphor is something even the police should keep an eye on." - G.C. Lichtenberg
Although the brain-computer metaphor has served cognitive psychology well, research in cognitive neuroscience has revealed many important differences between brains and computers. Appreciating these differences may be crucial to understanding the mechanisms of neural information processing, and ultimately for the creation of artificial intelligence. Below, I review the most important of these differences (and the consequences to cognitive psychology of failing to recognize them): similar ground is covered in this excellent (though lengthy) lecture.

Difference # 1: Brains are analogue; computers are digital

It's easy to think that neurons are essentially binary, given that they fire an action potential if they reach a certain threshold, and otherwise do not fire. This superficial similarity to digital "1's and 0's" belies a wide variety of continuous and non-linear processes that directly influence neuronal processing.

For example, one of the primary mechanisms of information transmission appears to be the rate at which neurons fire - an essentially continuous variable. Similarly, networks of neurons can fire in relative synchrony or in relative disarray; this coherence affects the strength of the signals received by downstream neurons. Finally, inside each and every neuron is a leaky integrator circuit, composed of a variety of ion channels and continuously fluctuating membrane potentials.

Failure to recognize these important subtleties may have contributed to Minksy & Papert's infamous mischaracterization of perceptrons, a neural network without an intermediate layer between input and output. In linear networks, any function computed by a 3-layer network can also be computed by a suitably rearranged 2-layer network. In other words, combinations of multiple linear functions can be modeled precisely by just a single linear function. Since their simple 2-layer networks could not solve many important problems, Minksy & Papert reasoned that that larger networks also could not. In contrast, the computations performed by more realistic (i.e., nonlinear) networks are highly dependent on the number of layers - thus, "perceptrons" grossly underestimate the computational power of neural networks.

Difference # 2: The brain uses content-addressable memory

In computers, information in memory is accessed by polling its precise memory address. This is known as byte-addressable memory. In contrast, the brain uses content-addressable memory, such that information can be accessed in memory through "spreading activation" from closely related concepts. For example, thinking of the word "fox" may automatically spread activation to memories related to other clever animals, fox-hunting horseback riders, or attractive members of the opposite sex.

The end result is that your brain has a kind of "built-in Google," in which just a few cues (key words) are enough to cause a full memory to be retrieved. Of course, similar things can be done in computers, mostly by building massive indices of stored data, which then also need to be stored and searched through for the relevant information (incidentally, this is pretty much what Google does, with a few twists).

Although this may seem like a rather minor difference between computers and brains, it has profound effects on neural computation. For example, a lasting debate in cognitive psychology concerned whether information is lost from memory because of simply decay or because of interference from other information. In retrospect, this debate is partially based on the false asssumption that these two possibilities are dissociable, as they can be in computers. Many are now realizing that this debate represents a false dichotomy.

Difference # 3: The brain is a massively parallel machine; computers are modular and serial

An unfortunate legacy of the brain-computer metaphor is the tendency for cognitive psychologists to seek out modularity in the brain. For example, the idea that computers require memory has lead some to seek for the "memory area," when in fact these distinctions are far more messy. One consequence of this over-simplification is that we are only now learning that "memory" regions (such as the hippocampus) are also important for imagination, the representation of novel goals, spatial navigation, and other diverse functions.

Similarly, one could imagine there being a "language module" in the brain, as there might be in computers with natural language processing programs. Cognitive psychologists even claimed to have found this module, based on patients with damage to a region of the brain known as Broca's area. More recent evidence has shown that language too is computed by widely distributed and domain-general neural circuits, and Broca's area may also be involved in other computations (see here for more on this).

Difference # 4: Processing speed is not fixed in the brain; there is no system clock

The speed of neural information processing is subject to a variety of constraints, including the time for electrochemical signals to traverse axons and dendrites, axonal myelination, the diffusion time of neurotransmitters across the synaptic cleft, differences in synaptic efficacy, the coherence of neural firing, the current availability of neurotransmitters, and the prior history of neuronal firing. Although there are individual differences in something psychometricians call "processing speed," this does not reflect a monolithic or unitary construct, and certainly nothing as concrete as the speed of a microprocessor. Instead, psychometric "processing speed" probably indexes a heterogenous combination of all the speed constraints mentioned above.

Similarly, there does not appear to be any central clock in the brain, and there is debate as to how clock-like the brain's time-keeping devices actually are. To use just one example, the cerebellum is often thought to calculate information involving precise timing, as required for delicate motor movements; however, recent evidence suggests that time-keeping in the brain bears more similarity to ripples on a pond than to a standard digital clock.

Difference # 5 - Short-term memory is not like RAM

Although the apparent similarities between RAM and short-term or "working" memory emboldened many early cognitive psychologists, a closer examination reveals strikingly important differences. Although RAM and short-term memory both seem to require power (sustained neuronal firing in the case of short-term memory, and electricity in the case of RAM), short-term memory seems to hold only "pointers" to long term memory whereas RAM holds data that is isomorphic to that being held on the hard disk. (See here for more about "attentional pointers" in short term memory).

Unlike RAM, the capacity limit of short-term memory is not fixed; the capacity of short-term memory seems to fluctuate with differences in "processing speed" (see Difference #4) as well as with expertise and familiarity.

Difference # 6: No hardware/software distinction can be made with respect to the brain or mind

For years it was tempting to imagine that the brain was the hardware on which a "mind program" or "mind software" is executing. This gave rise to a variety of abstract program-like models of cognition, in which the details of how the brain actually executed those programs was considered irrelevant, in the same way that a Java program can accomplish the same function as a C++ program.

Unfortunately, this appealing hardware/software distinction obscures an important fact: the mind emerges directly from the brain, and changes in the mind are always accompanied by changes in the brain. Any abstract information processing account of cognition will always need to specify how neuronal architecture can implement those processes - otherwise, cognitive modeling is grossly underconstrained. Some blame this misunderstanding for the infamous failure of "symbolic AI."

Difference # 7: Synapses are far more complex than electrical logic gates

Another pernicious feature of the brain-computer metaphor is that it seems to suggest that brains might also operate on the basis of electrical signals (action potentials) traveling along individual logical gates. Unfortunately, this is only half true. The signals which are propagated along axons are actually electrochemical in nature, meaning that they travel much more slowly than electrical signals in a computer, and that they can be modulated in myriad ways. For example, signal transmission is dependent not only on the putative "logical gates" of synaptic architecture but also by the presence of a variety of chemicals in the synaptic cleft, the relative distance between synapse and dendrites, and many other factors. This adds to the complexity of the processing taking place at each synapse - and it is therefore profoundly wrong to think that neurons function merely as transistors.

Difference #8: Unlike computers, processing and memory are performed by the same components in the brain

Computers process information from memory using CPUs, and then write the results of that processing back to memory. No such distinction exists in the brain. As neurons process information they are also modifying their synapses - which are themselves the substrate of memory. As a result, retrieval from memory always slightly alters those memories (usually making them stronger, but sometimes making them less accurate - see here for more on this).

Difference # 9: The brain is a self-organizing system

This point follows naturally from the previous point - experience profoundly and directly shapes the nature of neural information processing in a way that simply does not happen in traditional microprocessors. For example, the brain is a self-repairing circuit - something known as "trauma-induced plasticity" kicks in after injury. This can lead to a variety of interesting changes, including some that seem to unlock unused potential in the brain (known as acquired savantism), and others that can result in profound cognitive dysfunction (as is unfortunately far more typical in traumatic brain injury and developmental disorders).

One consequence of failing to recognize this difference has been in the field of neuropsychology, where the cognitive performance of brain-damaged patients is examined to determine the computational function of the damaged region. Unfortunately, because of the poorly-understood nature of trauma-induced plasticity, the logic cannot be so straightforward. Similar problems underlie work on developmental disorders and the emerging field of "cognitive genetics", in which the consequences of neural self-organization are frequently neglected .

Difference # 10: Brains have bodies

This is not as trivial as it might seem: it turns out that the brain takes surprising advantage of the fact that it has a body at its disposal. For example, despite your intuitive feeling that you could close your eyes and know the locations of objects around you, a series of experiments in the field of change blindness has shown that our visual memories are actually quite sparse. In this case, the brain is "offloading" its memory requirements to the environment in which it exists: why bother remembering the location of objects when a quick glance will suffice? A surprising set of experiments by Jeremy Wolfe has shown that even after being asked hundreds of times which simple geometrical shapes are displayed on a computer screen, human subjects continue to answer those questions by gaze rather than rote memory. A wide variety of evidence from other domains suggests that we are only beginning to understand the importance of embodiment in information processing.

Bonus Difference: The brain is much, much bigger than any [current] computer

Accurate biological models of the brain would have to include some 225,000,000,000,000,000 (225 million billion) interactions between cell types, neurotransmitters, neuromodulators, axonal branches and dendritic spines, and that doesn't include the influences of dendritic geometry, or the approximately 1 trillion glial cells which may or may not be important for neural information processing. Because the brain is nonlinear, and because it is so much larger than all current computers, it seems likely that it functions in a completely different fashion. (See here

for more on this.) The brain-computer metaphor obscures this important, though perhaps obvious, difference in raw computational power

HISTORY OF INDIA

Indian History - Important events

History of India . An overview : The people of India have had a continuous civilization since 2500 B.C., when the inhabitants of the Indus River valley developed an urban culture based on commerce and sustained by agricultural trade. This civilization declined around 1500 B.C., probably due to ecological changes.

During the second millennium B.C., pastoral, Aryan-speaking tribes migrated from the northwest into the subcontinent. As they settled in the middle Ganges River valley, they adapted to antecedent cultures.

The political map of ancient and medieval India was made up of myriad kingdoms with fluctuating boundaries. In the 4th and 5th centuries A.D., northern India was unified under the Gupta Dynasty. During this period, known as India's Golden Age, Hindu culture and political administration reached new heights.

Islam spread across the Indian subcontinent over a period of 500 years. In the 10th and 11th centuries, Turks and Afghans invaded India and established sultanates in Delhi. In the early 16th century, descendants of Genghis Khan swept across the Khyber Pass and established the Mughal (Mogul) Dynasty, which lasted for 200 years. From the 11th to the 15th centuries, southern India was dominated by Hindu Chola and Vijayanagar Dynasties. During this time, the two systems--the prevailing Hindu and Muslim--mingled, leaving lasting cultural influences on each other.

The first British outpost in South Asia was established in 1619 at Surat on the northwestern coast. Later in the century, the East India Company opened permanent trading stations at Madras, Bombay, and Calcutta, each under the protection of native rulers.

The British expanded their influence from these footholds until, by the 1850s, they controlled most of present-day India, Pakistan, and Bangladesh. In 1857, a rebellion in north India led by mutinous Indian soldiers caused the British Parliament to transfer all political power from the East India Company to the Crown. Great Britain began administering most of India directly while controlling the rest through treaties with local rulers. In the late 1800s, the first steps were taken toward self-government in British India with the appointment of Indian councilors to advise the British viceroy and the establishment of provincial councils with Indian members; the British subsequently widened participation in legislative councils. Beginning in 1920, Indian leader Mohandas K. Gandhi transformed the Indian National Congress political party into a mass movement to campaign against British colonial rule. The party used both parliamentary and nonviolent resistance and non-cooperation to achieve independence.

On August 15, 1947, India became a dominion within the Commonwealth, with Jawaharlal Nehru as Prime Minister. Enmity between Hindus and Muslims led the British to partition British India, creating East and West Pakistan, where there were Muslim majorities. India became a republic within the Commonwealth after promulgating its constitution on January 26, 1950.

After independence, the Congress Party, the party of Mahatma Gandhi and Jawaharlal Nehru, ruled India under the influence first of Nehru and then his daughter and grandson, with the exception of two brief periods in the 1970s and 1980s.

Prime Minister Nehru governed India until his death in 1964. He was succeeded by Lal Bahadur Shastri, who also died in office. In 1966, power passed to Nehru's daughter, Indira Gandhi, Prime Minister from 1966 to 1977. In 1975, beset with deepening political and economic problems, Mrs. Gandhi declared a state of emergency and suspended many civil liberties. Seeking a mandate at the polls for her policies, she called for elections in 1977, only to be defeated by Moraji Desai, who headed the Janata Party, an amalgam of five opposition parties.

In 1979, Desai's Government crumbled. Charan Singh formed an interim government, which was followed by Mrs. Gandhi's return to power in January 1980. On October 31, 1984, Mrs. Gandhi was assassinated, and her son, Rajiv, was chosen by the Congress (I)--for "Indira"--Party to take her place. His government was brought down in 1989 by allegations of corruption and was followed by V.P. Singh and then Chandra Shekhar.

In the 1989 elections, although Rajiv Gandhi and Congress won more seats in the 1989 elections than any other single party, he was unable to form a government with a clear majority. The Janata Dal, a union of opposition parties, was able to form a government with the help of the Hindu-nationalist Bharatiya Janata Party (BJP) on the right and the communists on the left. This loose coalition collapsed in November 1990, and the government was controlled for a short period by a breakaway Janata Dal group supported by Congress (I), with Chandra Shekhar as Prime Minister. That alliance also collapsed, resulting in national elections in June 1991.

On May 27, 1991, while campaigning in Tamil Nadu on behalf of Congress (I), Rajiv Gandhi was assassinated, apparently by Tamil extremists from Sri Lanka. In the elections, Congress (I) won 213 parliamentary seats and put together a coalition, returning to power under the leadership of P.V. Narasimha Rao. This Congress-led government, which served a full 5-year term, initiated a gradual process of economic liberalization and reform, which has opened the Indian economy to global trade and investment. India's domestic politics also took new shape, as traditional alignments by caste, creed, and ethnicity gave way to a plethora of small, regionally based political parties. 

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INDIAN PERSONALITIES

INDIAN EMINENT PERSONALITIES


                  BEAUTY QUEENS

	• Aishwarya Rai	• Priyanka Chopra
	• Diana Hayden	• Lara Dutta
• Sushmita Sen	• Yukta Mookhey

     
                      BUSINESSMEN

	• Azim H. Premji	• D. H. Ambani	• G. D. Birla
	• J. Tata	• J R D Tata	• N R N Murthy
	• Swraj Paul	• Sabeer Bhatia

  

                              DANCERS

• Alarmel Valli

• Mallika Sarabhai

• Anita Ratnam

• Sonal Mansingh

• Birju Maharaj

• Yamini Krishnamurthy

• Chitra Vishweswaran

• More...

       FILM PERSONALTIES    

	• Amitabh Bachchan	• Aparna Sen
	• Aishwarya Rai	• Dadasaheb Phalke
	• Gulzar	• Guru Dutt
	• Ismail Merchant	• Kamal Amrohi
	• M.N.Shyamalan	• Mira Nair
	• Nargis Dutt	• Priyanka Chopra
	• Raj Kapoor	• Satyajit Ray
	• Shabana Azmi	• more..

          LITERARY FIGURES

• Arundhati Roy	• R.K.Narayan	• Kalidasa
• Salman Rushdie	• Madavikutty	• Mirza Ghalib
• R. Tagore	• S. Bharati	• More...

                              MUSICIANS

	• Asha Bhonsale	• Pandit Bhimsen Joshi	• Lata Mangeshkar
	• Dr. Balamurali Krishna	• Ravi Shankar	• Pandit Hariprasad Chaurasia
	• Dr. L. Subramaniam	• Ustad Amjad Ali Khan	• S.Janaki
	• K.S.Chitra	• A.R.Rahman	• Ustad Bade Gulam Ali Khan
	• Lalgudi Jayaraman	• Dr. M.S. Subbalakshmi	• Yesudas
	• Mohammed Rafi	• Kishore Kumar	• More...

                        POLITICIANS                                             

	• A. B. Vajpayee	• Manmohan Singh	• Mahatma Gandhi
	• C Shekhar Azad	• Subash C Bose	• Rajiv Gandhi
	• Dr.Abdul Kalam	• Dr. B.R. Ambedkar	• K. R Gowri Amma
	• Jawaharlal Nehru	• Indira Gandhi	• More...

        SOCIAL REFORMERS

• Annie Besant	• Dr. B.R. Ambedkar
• Mother Teresa	• More...

                                PAINTERS

• M.F.Hussain

                    SPORTSPERSON

• Anju Bobby George	• Rahul Dravid	• Mihir Sen
• Gama Pehalwan	• Sourav Ganguly	• Prakash Padukone
• Karnam Malleswari	• Tenzing Norgay	• P.T.Usha
• Mahesh Bhupathi	• Dhyan Chand	• Sachin Tendulkar
• Milkha Singh	• Kapil Dev	• Sunil Gavaskar
• Pullela Gopichand	• Leander Paes	• More...

                           SCIENTISTS

• C.V.Raman	• S. Ramanujan	• Dr. S. Chandrasekhar
• Dr. H. Khorana	• Dr.H.J.Bhabha	• Shanti.S.Bhatnagar
• Meghnad Saha	• J.C.Bose	• Vikram.A.Sarabhai
• Shakuntala Devi

PERSONALTIESABROAD

• Amartya Sen	• Manoj Night Shyamalan	• G. D. Birla
• Sabeer Bhatia	• Ismail Merchant	•  more..
• Jagdish N. Bhagvati	• Swraj Paul