Wednesday, December 16, 2009
Guglielmo Marchese Marconi
Guglielmo Marchese MarconiMarconi is a Nobel laureate physicist from Italy. He is best known for his invention of Radio and he first introduced wireless telegraph system. He was born to a landowner father Giuseppe Marconi and his mother was Annie Jameson. He was very interested to science form his early life. He initially started working on electromagnetic wave or radio waves invented by Heinrich Hertz. Then after a long research he could figure out such a technology to communicate without wire. After his invention, he marketed this equipment for the commercial purpose and at that time he got a competitor free market in the U.S.
Aristotle
Aristotle is the Great philosopher who had a vast knowledge in different disciplines. Studying different subject he contributed a lot in each of those subjects. He contributed in physics, poetry, zoology, logic, rhetoric, politics, government, ethics, and biology. This laurel Greek philosopher was born in Stagira in 384 BC. His father Nicomachus was a physician to the king Amyntas III of Macedon’s court and it is believed that their ancestors also held this position. Earlier in his life he was taught by his father at home and the medical knowledge he got from his father led him to investigate natural phenomenon later on. At the age of 18 he admitted in to the young Greek aristocracy run by Plato, another Great Greek philosopher, and Aristotle became the most favorite student of Plato.Thomas Elva Edison
Thomas EdisonEdison is the great inventor who has over 1000 patents and his inventions are in various fields used in our daily life. In his early life he was thought to have a learning disability and he could not read till he was twelve and later he himself admitted that he became deaf after pulling up to a train car by his ears. He first could able to turn the attention of the world after inventing Phonograph. His one of the most popular invention is the Electric Bulb. He also developed the telegraph system. His invention of carbon telephone transmitter developed the carbon microphone which was used in the telephoned till 1980. He also became a prominent businessman and his business institution produced his inventions and marketed the products to the general people.
Sir Jagadish Chandra Bose
Sir Jagadish Chandra BoseHe was the first renowned Bengali scientist who had an important contribution in the invention of Radio and microwave optics. He was born in Mymensingh in Bengal which is the current Munshiganj District in Bangladesh. He studied in Hare school in Kolkata and then he got his B.A. in Science degree from Calcutta University. Then he went to England and got a B.A. degree from Cambridge University and a B.Sc. from London University. After coming back to the country he started teaching Physics in the Presidency College at Kolkata. In his teaching career he had to prove his quality and talent as he was the first Indian to teach Science at the college. In 1894 he started to research on Radio wave to make wireless communication equipments. At the same time Italy’s Marconi also was researching on this project. He first invented "iron-mercury-iron coherer with telephone detector" and he is the first person to use a semiconductor junction to catch the radio waves. It is said that his work on millimeter wavelength made him 50 years ahead. Considering such things it is said that he was the real inventor of Radio but due to his less seriousness towards patent and the communication gap made Marconi to be regarded as the inventor of Radio.
After that he contributed in plant where he could make some vital theory of ascent of sap. In this research he showed that some living cells in the endodermis junction are the reason for the ascent of sap.
Theory of Relativity
Theory of RelativityEclipse of 1919 bearing testimony that the light of stars is indeed deflected by the sun as the light passes near the sun on its way to earth. The total solar eclipse allowed astronomers to -- for the first time -- analyse starlight near the edge of the sun, which had been previously inaccessible to observers due to the intense brightness of the sun. It also predicted the rate at which two neutron stars orbiting one another will move toward each other. When this phenomenon was first documented, general relativity proved itself accurate to better than a trillionth of a percent precision, thus making it one of the best confirmed principles in all of physics.
Space / Time / Perception
Einstein said that physical objects are not in space, but these objects are spatially extended. In other words, space does not exist, but only the perception of space. This observation by Einstein is quite profound as it extends way beyond objects in space because it can be applied to what artists call perspective. If you look at a painting that has perspective you will swear up and down and sideways that you are looking into space because the space that your mind sees has been spatially extended but doesn’t physically exist. In other words, you can’t walk into that painting. Spatial extensions are also done with light and shadow.
In general, perspective in painting is built by using triangles or combinations of triangles (squares / rectangles ) and light and shadow. In a more abstract sense, perspective is how you view the world. Here your perspective is generally based on life experiences / culture / beliefs. Your mind, after considering what you see, draws ( spatial ) conclusions. Once again space doesn’t exist.
Labels: Perspective, Space, Time
Tuesday, December 15, 2009
John Dalton
John Dalton
The theory that all matter is made of very small particles called atoms which cannot (by chemical means) be broken down into smaller units is not well established. It is, however, little more than a hundred and ninety years since John Dalton first propped his atomic theory.
Philosophers of former civilizations, in particular the Greek thinker, Demokritos (460 – 370 B.C.) had notions that all matter was made of some kind of elementary particles or atoms. So the concept of atoms was by no means new, but it fell to Dalton to develop the idea. By defining in more detail what he understood by atoms, Dalton cleared the way for those chemists who followed him to gain a better idea of the constitution of chemical substances and of the mechanism of chemical reactions.
Dalton included in his theory some important new ideas. He said that the atoms of any one element are identical in all respects and in particular they have exactly the same mass. Furthermore, different elements have atoms of different mass, the mass of its atoms being a characteristic of each element. Dalton also stated that when chemical combination occurs, small whole numbers of atoms join together.
Except for the slight modification which became necessary when isotopes were discovered, this theory is still accepted today. The various points are, however, more familiar as the basic chemical laws of Conservation of Mass, Constant composition and Multiple Proportions.
I was during the first decade of the nineteenth century that Dalton arrived at his atomic theory. At the time it was virtually impossible to make accurate measurements because the apparatus available was still quiet primitive. It is all the more remarkable; therefore, that Dalton’s theory has withstood the test of time. Although he carried out a whole series of experiments to test the various parts of his theory, the experimental errors involved were so large that he could not claim to have proved it conclusively.
Another valuable contribution which Dalton made to chemistry was his idea for representing chemical compounds visually. A distinctive circular symbol was used to denote the atoms of each element – hydrogen was a circle with a dot in the middle, while a circle with one vertical line through it denoted a nitrogen atom.
John Dalton was born of a Quarker family at Eaglesfiled, a small village in the English Lake District. In 1776, when only ten years old, he entered the service of Elihu Robinson, a wealthy Quaker, who taught him mathematic. In 1781, after a brief spell of teaching in the village school, he joined his brother who was a master at a school in Kendal.
It was during this period that he commenced a journal of meteorological observations which he kept up for the remainder of his life. He also collected butterflies and amassed a vast number of dried plants.
In 1793 he moved to Manchester. At first he taught mathematics and natural philosophy at New College, but after six years he resigned. Thereafter he devoted his life to research which he financed by giving private tuition.
The theory that all matter is made of very small particles called atoms which cannot (by chemical means) be broken down into smaller units is not well established. It is, however, little more than a hundred and ninety years since John Dalton first propped his atomic theory.
Philosophers of former civilizations, in particular the Greek thinker, Demokritos (460 – 370 B.C.) had notions that all matter was made of some kind of elementary particles or atoms. So the concept of atoms was by no means new, but it fell to Dalton to develop the idea. By defining in more detail what he understood by atoms, Dalton cleared the way for those chemists who followed him to gain a better idea of the constitution of chemical substances and of the mechanism of chemical reactions.
Dalton included in his theory some important new ideas. He said that the atoms of any one element are identical in all respects and in particular they have exactly the same mass. Furthermore, different elements have atoms of different mass, the mass of its atoms being a characteristic of each element. Dalton also stated that when chemical combination occurs, small whole numbers of atoms join together.
Except for the slight modification which became necessary when isotopes were discovered, this theory is still accepted today. The various points are, however, more familiar as the basic chemical laws of Conservation of Mass, Constant composition and Multiple Proportions.
I was during the first decade of the nineteenth century that Dalton arrived at his atomic theory. At the time it was virtually impossible to make accurate measurements because the apparatus available was still quiet primitive. It is all the more remarkable; therefore, that Dalton’s theory has withstood the test of time. Although he carried out a whole series of experiments to test the various parts of his theory, the experimental errors involved were so large that he could not claim to have proved it conclusively.
Another valuable contribution which Dalton made to chemistry was his idea for representing chemical compounds visually. A distinctive circular symbol was used to denote the atoms of each element – hydrogen was a circle with a dot in the middle, while a circle with one vertical line through it denoted a nitrogen atom.
John Dalton was born of a Quarker family at Eaglesfiled, a small village in the English Lake District. In 1776, when only ten years old, he entered the service of Elihu Robinson, a wealthy Quaker, who taught him mathematic. In 1781, after a brief spell of teaching in the village school, he joined his brother who was a master at a school in Kendal.
It was during this period that he commenced a journal of meteorological observations which he kept up for the remainder of his life. He also collected butterflies and amassed a vast number of dried plants.
In 1793 he moved to Manchester. At first he taught mathematics and natural philosophy at New College, but after six years he resigned. Thereafter he devoted his life to research which he financed by giving private tuition.
Johannes Kepler
Johannes Kepler
Johann Kepler (1571 – 1630) was a German astronomer and mathematician to whom scientists owe a great debt. It was he explained the way in which the planets move in our solar system. Earlier, Copernicus had shown that the planets travel around the Sun (and not, as thought, round the Earth) Galileo was able to confirm this by observation through his telescope.
Another important name in early astronomy was Tycho Brahe (1546 – 1601) who, although he did not accept Copernicus’s theories, spent much of his life in developing accurate measuring instruments and in compiling astronomical tables on the movements of the planets.
In 1600 Kepler was appointed Brahe’s assistant at an observatory in Prague. When Brahe died the following year, Kepler continued his work on the tables. When these were completed he had more information on the behavior of the planets than anyone had possessed before. With this knowledge, he was able to interpret their movements and to produce three basic laws by which they moved.
Kepler noted first that planets move round the Sun in an oval or elliptical path. Secondly he said that a line between a planet and the Sun swept out equal areas in equal times. In other words the nearer a planet is to the Sun, the faster it travels. His third law demonstrated that planets nearer the Sun have a shorter year than those further away from it.
These were by no means the only contribution made to astronomy by Kepler. He studied, for example, the passage of comets and the star explosions called novae. But his real achievement lay in his laws, which lad open the way for the great discoveries of Isaac Newton about gravity and motion.
Johann Kepler (1571 – 1630) was a German astronomer and mathematician to whom scientists owe a great debt. It was he explained the way in which the planets move in our solar system. Earlier, Copernicus had shown that the planets travel around the Sun (and not, as thought, round the Earth) Galileo was able to confirm this by observation through his telescope.
Another important name in early astronomy was Tycho Brahe (1546 – 1601) who, although he did not accept Copernicus’s theories, spent much of his life in developing accurate measuring instruments and in compiling astronomical tables on the movements of the planets.
In 1600 Kepler was appointed Brahe’s assistant at an observatory in Prague. When Brahe died the following year, Kepler continued his work on the tables. When these were completed he had more information on the behavior of the planets than anyone had possessed before. With this knowledge, he was able to interpret their movements and to produce three basic laws by which they moved.
Kepler noted first that planets move round the Sun in an oval or elliptical path. Secondly he said that a line between a planet and the Sun swept out equal areas in equal times. In other words the nearer a planet is to the Sun, the faster it travels. His third law demonstrated that planets nearer the Sun have a shorter year than those further away from it.
These were by no means the only contribution made to astronomy by Kepler. He studied, for example, the passage of comets and the star explosions called novae. But his real achievement lay in his laws, which lad open the way for the great discoveries of Isaac Newton about gravity and motion.
Benjamin Franklin
Benjamin FranklinAlthough he is chiefly remembered as an American statesman, Benjamin Franklin also made several valuable contributions to scientific knowledge. Born in 1706, the fifteenth child of a poor Boston family, he was mainly self taught, although he did attend the local grammar school for a while.
At the age of 12 he was apprenticed to a printer and five years later he left his home town for Philadelphia where he continued to practise his trade. By 1729 he had set p his own successful printing house and bought the Pennsylvania Gazette.
Soon after this he entered upon a career of public service, first as clerk to the general assembly of Pennsylvania. In 1751 he was himself elected to that body and from 1753 to 1774 he was deputy Postmaster-General for the North American colonies.
On a number of occasions Franklin visited England to negotiate with the British Government on behalf of the colonists. It was in the course of his voyages to England that he carried out a series of experiments to discover the nature and course of the Gulf Stream. This is a warm ocean current which flows from the Gulf of Mexico along the East coast of North America and then turns eastwards across the Atlantic from a point off the coast of Newfoundland. In plotting this current Franklin made regular determinations of the temperature at various depths in the ocean.
The nature of thunder and lightning had interested scientists and philosophers for centuries, but it fell to Franklin to investigate the nature of lightning experimentally. He had prepared a child’s kite with a wire spike attached to it. Near the other end of the string to which the kite was attached, he secured a key. He released the kite as a thundercloud passed overhead, and was soon able to draw a large electric spark from the key. This could have been very dangerous, had he not held the kite-string with an insulator. As the rain soaked into the string, thus increasing its electrical conductivity, electricity flowed freely down the string and was found to have the same properties by friction. The success of this experiment suggested the use of lightening conductors to protect tall buildings.
Another contribution which Franklin made to the study of electricity was to establish the existence of positive and negative charges.
Although it is not certain whether he invented them Benjamin Franklin was certainly the first person to describe bifocal spectacles. Previously, if anyone required lenses of different powers for reading and for seeing distant objects, two separate pairs of spectacles were required. However, this was avoided by having two half lenses cemented together. The lower half-lens gave suitable magnification for reading, while the upper half was less powerful and was used for focusing on objects further away.
Franklin was too much concerned in politics to devote much time in his later life to science. He helped draw up the Declaration of Independence, and shortly before his death in 1790, he was campaigning for the abolition of negro slavery.
Louis De Broglie
Louis De Broglie
During the last three hundred years scientists have spent a great deal of time discussing and investigating the nature of light. In the seventeenth century Sir Isaac Newton believed that light rays consisted of streams of very small particles. This Corpuscular Theory persisted for many years through Christian Huygens, a contemporary of Newton, had the notion that light might be transmitted by vibrations (i.e. waves) in the ether.
However, at the beginning of the nineteenth century Thomas Young carried out his famous interference experiments. His observations could be explained only by assuming that light is transmitted as waves and not as a stream of particles. Furthermore the Wave Theory seemed to account for all experimental observations made at that time, and it appeared that this theory had replaced the Corpuscular theory for all time.
Then at the end of the nineteenth century it was found that under certain conditions electrons were liberated when light feel on a surface. The Wave theory could not explain this photoelectric effect. This startling new discovery left physicists with a serious dilemma. The photoelectric effect could best be explained by reverting to Corpuscular Theory, although almost all other evidence pointed to light’s being a form of wave motion.
These were some of the theoretical problems which faced physicists when Louis De Broglie, a young Frenchman of noble birth, came on the scene. In a thesis published in 1922, when he was only thirty years old, he suggested that light could behave either as a wave or as a steam of particles, but not both at the same time.
He argued that if light which was normally a form of wave motion could take on a corpuscular (particle) form, then small particles such as electrons could also have wave-like characteristics associated with them. However, he had to wait five years for the evidence. Then in 1927 two Americans, Clinton J. Davisson and L.H. Germer working at the Bell Telephone Laboratory succeeded in diffracting (bending into shadows) a beam of electrons using a crystal as the diffraction grating.
De Broglie’s dual theory can be applied to any moving particle whatever its nature. The wavelength of the ‘de Broglie’ wave (the wave associated with the particle) is found by dividing the momentum of the particle into Planck’s constant.
During the last three hundred years scientists have spent a great deal of time discussing and investigating the nature of light. In the seventeenth century Sir Isaac Newton believed that light rays consisted of streams of very small particles. This Corpuscular Theory persisted for many years through Christian Huygens, a contemporary of Newton, had the notion that light might be transmitted by vibrations (i.e. waves) in the ether.
However, at the beginning of the nineteenth century Thomas Young carried out his famous interference experiments. His observations could be explained only by assuming that light is transmitted as waves and not as a stream of particles. Furthermore the Wave Theory seemed to account for all experimental observations made at that time, and it appeared that this theory had replaced the Corpuscular theory for all time.
Then at the end of the nineteenth century it was found that under certain conditions electrons were liberated when light feel on a surface. The Wave theory could not explain this photoelectric effect. This startling new discovery left physicists with a serious dilemma. The photoelectric effect could best be explained by reverting to Corpuscular Theory, although almost all other evidence pointed to light’s being a form of wave motion.
These were some of the theoretical problems which faced physicists when Louis De Broglie, a young Frenchman of noble birth, came on the scene. In a thesis published in 1922, when he was only thirty years old, he suggested that light could behave either as a wave or as a steam of particles, but not both at the same time.
He argued that if light which was normally a form of wave motion could take on a corpuscular (particle) form, then small particles such as electrons could also have wave-like characteristics associated with them. However, he had to wait five years for the evidence. Then in 1927 two Americans, Clinton J. Davisson and L.H. Germer working at the Bell Telephone Laboratory succeeded in diffracting (bending into shadows) a beam of electrons using a crystal as the diffraction grating.
De Broglie’s dual theory can be applied to any moving particle whatever its nature. The wavelength of the ‘de Broglie’ wave (the wave associated with the particle) is found by dividing the momentum of the particle into Planck’s constant.
Louis Victor De Broglie was born as Dieppe in France in 1892. His elder brother Maurice the sixth Duc de Broglie, was also a physicist of some note. Louis was at first interested in history and literature, but after serving in the French army during World War I he took up physics.
In recognition of his contribution to the advance of theoretical physics, Louis de Broglie was awarded the Noble Prize in 1929. Since 1928 he has been Professor of theoretical physics at the University of Paris where he had previously received his training.
Blaise Pascal
Blaise Pascal
Mechanical aids to calculating, such as the abacus or counting frame have been used for thousands of years. The first real calculating machine (i.e. one where the result or total could be read off directly) was devised by Blaise Pascal in 1642. Pascal originally designed it to help his father in his work of adding and subtracting money. Several machines were built using the same principle. The one described here is dated 1652, and the original is to be found in the Conservatoire des Arts et Metiers in Paris. A copy can be seen in the Science Museum, London.
Pascal’s machine embodies many of the principles still used in calculators. It consists of a box containing six sets of pinwheels and cylinders. Each cylinder bears the figures 0-9 around its edge, and is so arranged that only one figure – equivalent to of the circumference – can be seen through the sighthole at any given time. The pinwheels are connected to the six horizontal dials (rather like a telephone dial and marked from 0-9) at the front, so that when the dial is turned, the corresponding pinwheel and the cylinder turn with it.
To follow the method of using the calculator, suppose that the operator wishes to add together the numbers 2, 5 and 3. With a stylus or peg he turns the right hand dial anticlockwise from where the figure 2 is marked round to 0. The dial moves in the opposite direction to the dial on a telephone and it does not spring back to its starting position when the peg is removed. This action turns the pinwheel and hence the cylinder of a revolution from 0-2. The operator now repeats the process, this time ‘dialling’ 5. The pinwheel turns the cylinder a further of a revolution, so that the total registered there is 7. Once again he dials a number, in this example number 3. The pinwheel moves through of a turn, as does the cylinder. Because the cylinder is marked in tenths, however, and ten units have been added (2+5+3), this brings it round to 0 again. A trip-mechanism within the calculator, however, ‘carries’ the figure 1 to the cylinder immediately to the left, i.e. it turns the next wheel of a revolution, from 0 to 1. There are six cylinders altogether, which represent (from right to left) single figures, tens, hundreds, thousands, ten thousands and hundreds of thousands respectively. The adding of the singlefigures 2,5 and 3 gives 0 in the single figure cylinder and 1 on the tens cylinder, thus producing the answer total 10. With the six cylinders sums can be added up to a total of 999,999. In face the model described has two sets of numbers on the ‘dials’ and the cylinders, the second set running in the reverse direction (i.e. from 9-0 instead of 0-9). The latter can be used for subtraction, and are covered up on the cylinders by a sliding strip of metal when not in use.
Some of Pascal’s machines were designed for adding livres, sous and deniers (the contemporary French equivalent of our pounds, shillings and pence), and may be regarded as the forerunners of modern cash registers.
Although his invention of the calculating machine is important, Pascal is not thought of primarily as an inventor. His work ranged over physics, mathematics and philosophy. Born at Clermont-Ferrand in 1623, Pascal became interested in mathematics at an early age. He is reputed to have worked out for himself at the age of 12 many of the geometrical ideas of Euclid. He constructed his first calculating machine before he was 20. A few years later he was able to show, by experimenting with barometers, that the pressure of the atmosphere decreases with altitude.
Pascal’s machine
Pascal is remembered nowadays, some 300 years after his death, through Pascal’s Law of fluid pressure and Pascal’s Triangle. The law of fluid pressure which resulted from his work on hydrostatics underlies the action of hydraulic jacks, hydraulic presses and similar machines. Pascal’s Triangle is a well known pattern of numbers which is used in the studies of chance and probability.
The extent of Pascal’s work is all the more striking in view of the fact that he suffered form poor health all his life and that he was only 39 when he died in 1662.
Sir Isaac Newton
Isaac Newton, SirThe English mathematician and natural philosopher Sir Isaac Newton (1642-1727) made many important contributions to the study of physics, even apart from his famous laws of motion and gravity. It has been said that his studies in light alone would have placed him amongst the front rank of scientists.
About 1666 he passed sunlight through a triangular glass prism and obtained the spectrum of colours. The sunlight was dispersed (split up) by the prism into its component colours, spread out on the paper.
This is the same effect as in the rainbow (where the raindrops act as prisms). Although theories of the rainbow had been put forward at least half a century before this, Newton cleared up the subject by passing the spectrum back through another prism and producing white light once more. This was final proof that white light is made up of all the colours in the rainbow or spectrum.
Another experiment in the same field was carried out using a colour wheel. This is a disc, painted in the colours of the spectrum, which can be spun round rapidly by turning a handle. The somewhat surprising result is that when it is turned rapidly, the disc apparently changes colour and becomes completely white. “White” light is thus shown to be made up of all colours in the rainbow.
About 1666 he passed sunlight through a triangular glass prism and obtained the spectrum of colours. The sunlight was dispersed (split up) by the prism into its component colours, spread out on the paper.
This is the same effect as in the rainbow (where the raindrops act as prisms). Although theories of the rainbow had been put forward at least half a century before this, Newton cleared up the subject by passing the spectrum back through another prism and producing white light once more. This was final proof that white light is made up of all the colours in the rainbow or spectrum.
Another experiment in the same field was carried out using a colour wheel. This is a disc, painted in the colours of the spectrum, which can be spun round rapidly by turning a handle. The somewhat surprising result is that when it is turned rapidly, the disc apparently changes colour and becomes completely white. “White” light is thus shown to be made up of all colours in the rainbow.
Anton van Leeuwenhoek
Anton van Leeuwenhoek was born in the town of Delft, Holland, in 1632. He had a rather unusual background for a scientist, beginning in the cloth trade in Amsterdam, and then becoming City Chamberlain of his native town. He became interested in the making of microscopes, however, and used them enthusiastically in his studies almost until his death in 1723.
The Microscopes
Leeuwenhoek’s microscopes were not at all like those seen in present-day laboratories. They had only one small lens, almost spherical, mounted between metal plates. Such a lens, although difficult to produce, gave considerable better magnification than any other microscope of the time. Leeuwenhoek did not invent the microscope (Galileo, often credited with the invention, is known to have used one some fifty years previously). His achievement lay rather in his skill in setting and grinding the lens more accurately than had been possible before.
Blood and the Circulation
One well-known study by the Dutch scientist was concerned with the circulation of the blood. William Harvey had made the great discovery of the circulation about 1616, but there remained the problem of how blood from the arteries was actually transferred to the veins to be returned to the heart. Leeuwenhoek’s work, together with that of another microscopist, Marcello Malpighi, showed that it passed through tiny tubes we now know as capillaries. In other studies Leeuwenhoek examined the structure of the skin, hair, teeth and the eye, observed minute creatures (now called Protozoa) in pond water, identified the eggs and pupae of ants and considered a host of other biological subjects.
Observation of Bacteria
Leeuwenhoek’s greatest success came, however, when he examined the tartar from hi own teeth. To his great surprise he saw that there were in the tartar ‘a large number of “little beasties” moving about in a highly amusing way’. The largest of them, he noted, ‘showed the liveliest and most active motion, passing through the saliva as a fish of prey darts through the sea’. This was almost certainly the first observation of the tiny plants called bacteria which are so important in our lives as agents of decay and disease.
This Dutch scientist was by no means the only pioneer in the use of the microscope. Robert Hooke, Nehemiah Grew, Marcello Malpighi and Jan Swammerdam were amongst the most famous early workers, opening a vast new field of research into the world of creatures too tiny to see with the naked eye.
Charles Darwin
Charles Darvin
It is probably true to say that no scientific publication during the nineteenth century started a bigger storm of general protest and argument than a book produced in 1859. It was called The Origin of Species by Means of Natural Selection by a biologist called Charles Darwin. The book put forward the scientist’s ideas on the evolution of plants and animals from simple forms by a process of a slow, gradual change. It was a rather revolutionary idea, for before that time the vast majority of scientific workers accepted the belief that all living things were created in their present form. Even today there are a great many people who feel that Darwin’s theory is not completely acceptable.
Charles Robert Darwin was born in Shrewsbury in 1809. After attending Shrewsbury School and training for medicine at Edinburgh University, he went to Cambridge to take a degree with the idea of finally being ordained as a priest. In fact, however, on leaving Cambridge in 1831 he took up a quite different career. Darwin had long been interested in natural history and his big chance came when Captain Fitzroy of H.M.S. Beagle offered to take him on his official surveying voyage around the world. The tour lasted for about five years (1831-6), during which time Darwin found a great deal to interest himself.
On the Galapagos Islands, off the west coast of South America, for example, he saw birds which showed marked differences in structure from those on the mainland. This gave him the idea that perhaps the differences between the conditions there and the mainland were at least partly responsible for the ways in which the birds differed. Could it be, he asked, that only those animals and plants best suited to their surroundings could survive in the fierce struggle for existence? He found plenty of evidence that this may have been so. Over the millions of years which the Earth has taken to develop, quite startling differences in plants and animals could result. Ancient, primitive creatures such as the dinosaur died out because conditions were no longer right for them. Other animals – the giraffe, for instance – can survive in conditions where the only food to be found is high above ground, because their long necks enable them to reach it. Smaller species would have much greater difficulty in finding food in such places, if they could not climb trees, and would tend to die out. Reasoning in such ways, Darwin came to the conclusion that plants and animals have reached their present state by what he called Natural Selection, the weeding out by Nature which leaves only those animals best fitted for their conditions. Because conditions vary from place to place and have varied over the course of time, a vast range of animal and plant types has appeared and tried to live. Sometimes they have become extinct; sometimes they have survived to reproduce their kind.
It is a complicated theory, not easily described, and difficult if not impossible to prove conclusively without seeing all the links in the chain of developing plants and animals throughout history. Nor was it absolutely new, for other scientists before Darwin had sought to explain the variety and the similarities between creatures by various means. Darwin’s real achievement lay in looking at the problem in a systematic and scholarly way, putting his case before the public in a way which could be understood. (A fuller explanation of evolution will appear in later articles.)
Charles Darwin died in 1882. His tomb is in Westminster Abbey in London.
Biography Of Einstean
Albert Einstean
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(Born March 14, 1879, Ulm, Württemberg,
Ger.—died April 18, 1955, Princeton, N.J., U.S.) German-born physicist who developed the special and general theories of relativity and won the Nobel Prize for Physics in 1921 for his explanation of the photoelectric effect. Einstein is generally considered the most influential physicist of the 20th century.
(Born March 14, 1879, Ulm, Württemberg,
Ger.—died April 18, 1955, Princeton, N.J., U.S.) German-born physicist who developed the special and general theories of relativity and won the Nobel Prize for Physics in 1921 for his explanation of the photoelectric effect. Einstein is generally considered the most influential physicist of the 20th century.
Education
Einstein's parents were secular, middle-class Jews. His father, Hermann Einstein, was originally a featherbed salesman and later ran an electrochemical factory with moderate success. His mother, the former Pauline Koch, ran the family household. He had one sister, Maja, born two years after Albert.
Einstein would write that two “wonders” deeply affected his early years. The first was his encounter with a compass at age five. He was mystified that invisible forces could deflect the needle. This would lead to a lifelong fascination with invisible forces. The second wonder came at age 12 when he discovered a book of geometry, which he devoured, calling it his “sacred little geometry book.”
Einstein became deeply religious at age 12, even composing several songs in praise of God and chanting religious songs on the way to school. This began to change, however, after he read science books that contradicted his religious beliefs. This challenge to established authority left a deep and lasting impression. At the Luitpold Gymnasium, Einstein often felt out of place and victimized by a Prussian-style educational system that seemed to stifle originality and creativity. One teacher even told him that he would never amount to anything.
Yet another important influence on Einstein was a young medical student, Max Talmud (later Max Talmey), who often had dinner at the Einstein home. Talmud became an informal tutor, introducing Einstein to higher mathematics and philosophy. A pivotal turning point occurred when Einstein was 16. Talmud had earlier introduced him to a children's science series by Aaron Bernstein, Naturwissenschaftliche Volksbucher (1867–68; Popular Books on Physical Science), in which the author imagined riding alongside electricity that was traveling inside a telegraph wire. Einstein then asked himself the question that would dominate his thinking for the next 10 years: What would a light beam look like if you could run alongside it? If light were a wave, then the light beam should appear stationary, like a frozen wave. Even as a child, though, he knew that stationary light waves had never been seen, so there was a paradox. Einstein also wrote his first “scientific paper” at that time (“The Investigation of the State of Aether in Magnetic Fields”).
Page: 2
Einstein's education was disrupted by his father's repeated failures at business. In 1894, after his company failed to get an important contract to electrify the city of Munich, Hermann Einstein moved to Milan, Italy, to work with a relative. Einstein was left at a boarding house in Munich and expected to finish his education. Alone, miserable, and repelled by the looming prospect of military duty when he turned 16, Einstein ran away six months later and landed on the doorstep of his surprised parents. His parents realized the enormous problems that he faced as a school dropout and draft dodger with no employable skills. His prospects did not look promising.
Fortunately, Einstein could apply directly to the Eidgenössische Polytechnics Schule (“Swiss Federal Polytechnic School”; in 1911, following expansion in 1909 to full university status, it was renamed the Eidgenössische Technische Hochschule, or “Swiss Federal Institute of Technology”) in Zürich without the equivalent of a high school diploma if he passed its stiff entrance examinations. His marks showed that he excelled in mathematics and physics, but he failed at French, chemistry, and biology. Because of his exceptional math scores, he was allowed into the polytechnic on the condition that he first finish his formal schooling. He went to a special high school run by Jost Winteler in Aarau, Switz., and graduated in 1896. He also renounced his German citizenship at that time. (He was stateless until 1901, when he was granted Swiss citizenship.) He became lifelong friends with the Winteler family, with whom he had been boarding. (Winteler's daughter, Marie, was Einstein's first love; Einstein's sister Maja would eventually marry Winteler's son Paul; and his close friend Michele Besso would marry their eldest daughter, Anna.)
Einstein would recall that his years in Zürich were some of the happiest years of his life. He met many students who would become loyal friends, such as Marcel Grossmann, a mathematician, and Besso, with whom he enjoyed lengthy conversations about space and time. He also met his future wife, Mileva Maric, a fellow physics student from Serbia.
Independent scholar and special relativity
After graduation in 1900, Einstein faced one of the greatest crises in his life. Because he studied advanced subjects on his own, he often cut classes; this earned him the animosity of some professors, especially Heinrich Weber. Unfortunately, Einstein asked Weber for a letter of recommendation. Einstein was subsequently turned down for every academic position that he applied to. He later wrote,
I would have found [a job] long ago if Weber had not played a dishonest game with me.
Einstein's parents were secular, middle-class Jews. His father, Hermann Einstein, was originally a featherbed salesman and later ran an electrochemical factory with moderate success. His mother, the former Pauline Koch, ran the family household. He had one sister, Maja, born two years after Albert.
Einstein would write that two “wonders” deeply affected his early years. The first was his encounter with a compass at age five. He was mystified that invisible forces could deflect the needle. This would lead to a lifelong fascination with invisible forces. The second wonder came at age 12 when he discovered a book of geometry, which he devoured, calling it his “sacred little geometry book.”
Einstein became deeply religious at age 12, even composing several songs in praise of God and chanting religious songs on the way to school. This began to change, however, after he read science books that contradicted his religious beliefs. This challenge to established authority left a deep and lasting impression. At the Luitpold Gymnasium, Einstein often felt out of place and victimized by a Prussian-style educational system that seemed to stifle originality and creativity. One teacher even told him that he would never amount to anything.
Yet another important influence on Einstein was a young medical student, Max Talmud (later Max Talmey), who often had dinner at the Einstein home. Talmud became an informal tutor, introducing Einstein to higher mathematics and philosophy. A pivotal turning point occurred when Einstein was 16. Talmud had earlier introduced him to a children's science series by Aaron Bernstein, Naturwissenschaftliche Volksbucher (1867–68; Popular Books on Physical Science), in which the author imagined riding alongside electricity that was traveling inside a telegraph wire. Einstein then asked himself the question that would dominate his thinking for the next 10 years: What would a light beam look like if you could run alongside it? If light were a wave, then the light beam should appear stationary, like a frozen wave. Even as a child, though, he knew that stationary light waves had never been seen, so there was a paradox. Einstein also wrote his first “scientific paper” at that time (“The Investigation of the State of Aether in Magnetic Fields”).
Page: 2
Einstein's education was disrupted by his father's repeated failures at business. In 1894, after his company failed to get an important contract to electrify the city of Munich, Hermann Einstein moved to Milan, Italy, to work with a relative. Einstein was left at a boarding house in Munich and expected to finish his education. Alone, miserable, and repelled by the looming prospect of military duty when he turned 16, Einstein ran away six months later and landed on the doorstep of his surprised parents. His parents realized the enormous problems that he faced as a school dropout and draft dodger with no employable skills. His prospects did not look promising.
Fortunately, Einstein could apply directly to the Eidgenössische Polytechnics Schule (“Swiss Federal Polytechnic School”; in 1911, following expansion in 1909 to full university status, it was renamed the Eidgenössische Technische Hochschule, or “Swiss Federal Institute of Technology”) in Zürich without the equivalent of a high school diploma if he passed its stiff entrance examinations. His marks showed that he excelled in mathematics and physics, but he failed at French, chemistry, and biology. Because of his exceptional math scores, he was allowed into the polytechnic on the condition that he first finish his formal schooling. He went to a special high school run by Jost Winteler in Aarau, Switz., and graduated in 1896. He also renounced his German citizenship at that time. (He was stateless until 1901, when he was granted Swiss citizenship.) He became lifelong friends with the Winteler family, with whom he had been boarding. (Winteler's daughter, Marie, was Einstein's first love; Einstein's sister Maja would eventually marry Winteler's son Paul; and his close friend Michele Besso would marry their eldest daughter, Anna.)
Einstein would recall that his years in Zürich were some of the happiest years of his life. He met many students who would become loyal friends, such as Marcel Grossmann, a mathematician, and Besso, with whom he enjoyed lengthy conversations about space and time. He also met his future wife, Mileva Maric, a fellow physics student from Serbia.
Independent scholar and special relativity
After graduation in 1900, Einstein faced one of the greatest crises in his life. Because he studied advanced subjects on his own, he often cut classes; this earned him the animosity of some professors, especially Heinrich Weber. Unfortunately, Einstein asked Weber for a letter of recommendation. Einstein was subsequently turned down for every academic position that he applied to. He later wrote,
I would have found [a job] long ago if Weber had not played a dishonest game with me.
Stephen Hawkins
Stephen Hawkins
Stephen Hawking, world-renowned physicist and author of the novel A Brief History of Time, was born precisely 300 years after the death of Galileo, on the 8th of January 1942. His parents' house was in north London, but Hawking was born in Oxford as his parents were worried about the dangers of the Blitz. When he was eight, his family moved to St. Albans, a town about 20 miles north of London. When he was older, Hawking attended his father's alma mater, University College at Oxford. Though his father wanted him to study medicine, Hawking opted for physics (his preferred subject, mathematics, was not offered). After three years, during which his intellect allowed him to put in comparitively little effort, he was awarded a first class honours degree in Natural Science.
After recieving his degree, Hawking at first attempted to continue his studies at Oxford, however he quickly grew bored of astronomy, and since at the time Oxford was not pursuing research into Cosmolo...
After recieving his degree, Hawking at first attempted to continue his studies at Oxford, however he quickly grew bored of astronomy, and since at the time Oxford was not pursuing research into Cosmolo...
Monday, December 14, 2009
Sunday, December 13, 2009
William Herschel
William Herschel
William Herschel lived at a time when interest in astronomy was running high. There was still very much to be learned about our vast universe, the positions and behaviour of its many stars, planets etc. and many astronomers were busily amassing information.
At the time, there were available several excellent designs of telescopes, all theoretically good. But the problem lay in converting theory to practice. It was not easy to make a good telescope with the simple tools and techniques available. William Herschel’s name takes its place in history as the man who made some of the finest telescopes of his age and plotted large sections of the sky using them.
For Herschel, astronomy was a hobby. It grew into an obsession and in the end completely dominated his life. He was not a scientist by training, but a musician, Director of Music at the City of Bath, engaging artists for concerts and composing music to be sung and played.
Louis Pasteur
Louis Pasteur
He is one of the most famous contributors in the medical science. He first introduced the germ theory of diseases. This is regarded as the base of today’s microbiology. He found out some of the notion of the microbe and he could find out that the viruses were not detectable through microscope. Another important contribution of Pasteur is to protect harmful microbes in a way called “Pasteurization” where harmful microbes are destroyed by hitting the food. He is undoubtedly the most influential scientist in medical science.
He is one of the most famous contributors in the medical science. He first introduced the germ theory of diseases. This is regarded as the base of today’s microbiology. He found out some of the notion of the microbe and he could find out that the viruses were not detectable through microscope. Another important contribution of Pasteur is to protect harmful microbes in a way called “Pasteurization” where harmful microbes are destroyed by hitting the food. He is undoubtedly the most influential scientist in medical science.
Tuesday, January 27, 2009
Yella Pragadala Subbharao
He was born to a poor niyogi brahmin family in Bhimavaram of the Old Madras Presidency, now in West Godavary District, Andhra Pradesh. He passed through a traumatic period in his schooling at Rajahmundry (due to the premature death of close relations by disease) and eventually matriculated in his third attempt from the Hindu High School, Madras. He passed the Intermediate Examination from the Presidency College and entered the Madras Medical College where his education was supported by friends and Kasturi Suryanarayana Murthy, whose daughter he later married. Following Gandhi's call to boycott British goods he started wearing khadi surgical dress; this incurred the displeasure of M. C. Bradfield, his surgery professor. Consequently, though he did well in his written papers, he was awarded the lesser LMS certificate and not a full MBBS degree.
Subbarao tried to enter the Madras Medical Service without success. He then took up a job as Lecturer in Anatomy at Dr. Lakshmipathi's Ayurvedic College at Madras. He was fascinated by the healing powers of Ayurvedic medicines and began to engage in research to put Ayurveda on a modern footing.
A chance meeting with an American doctor, who was visiting on a Rockefeller Scholarship, changed his mind. The promise of support from Satyalinga Naicker Charities and Malladi Charities, Kakinada and financial assistance raised by his father-in-law, enabled Subbarao to proceed to the U.S. He arrived in Boston on October 26, 192
Subbarao tried to enter the Madras Medical Service without success. He then took up a job as Lecturer in Anatomy at Dr. Lakshmipathi's Ayurvedic College at Madras. He was fascinated by the healing powers of Ayurvedic medicines and began to engage in research to put Ayurveda on a modern footing.
A chance meeting with an American doctor, who was visiting on a Rockefeller Scholarship, changed his mind. The promise of support from Satyalinga Naicker Charities and Malladi Charities, Kakinada and financial assistance raised by his father-in-law, enabled Subbarao to proceed to the U.S. He arrived in Boston on October 26, 192
Satyendra Nath Bose
Satyendra Nath Bose was born on New Years day, 1894 in Goabaganin Kolkata. His father was an accountant in Indian Railways. Satyendra Nath
popularly known as Satyen Bose, did his schooling at Hindu School, Kolkata,
and then joined Presidency College. He excelled in academics throughout his
education – Intermediate, B.Sc. and M.Sc. with applied mathematics. His
teacher at the Presidency College was Jagadish Chandra Bose - whose other
stellar pupil was Meghnad Saha. Bose took his B.Sc. examination in 1913 and
his M.Sc examination in 1915. He stood first in both the examinations, the
second place going to Meghnad Saha.
He worked as a lecturer of physics in the Science College of the
University of Calcutta (1916-21) and along with Meghnad Saha, introduced
postgraduate courses in modern mathematics and physics. He derived with Saha, the Saha-Bose equation of state for a nonideal gas. In 1921, Bose left Kolkata to become a Reader at the Dakha University. It was during this period that he wrote the famous paper on the statistics of photons. It was named Bose statistics after him and is now an integral part of physics. Paul Dirac, the legendary physicist, coined the term boson for particles obeying these statistics. Apart from this he did theoretical work on the general theory of relativity and also experimental work on crystallography, fluorescence, and thermoluminescence.
Bose spent about 10 months in Paris in 1924, doing research with Madame Curie and Louis de Broglie. Later he went to Berlin where he met Einstein. He returned to Dhaka in 1926 and became Professor. Shortly before Independence, Bose returned to Kolkata to become the Khaira Professor of Physics, a post he kept till 1956. He was elected Fellow of the Royal Society in 1958, and the Government of India named him a National Professor and awarded him the honor of Padma Vibhushan.
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