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Great scientiest of the world

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Georg Simon Ohm (1787-1854)

Using the results of his experiments, Georg Simon Ohm was able to define the fundamental relationship between voltage, current, and resistance. These fundamental relationships are of such great importance, that they represent the true beginning of electrical circuit analysis.

Unfortunately, when Ohm published his finding in 1827, his ideas were dismissed by his colleagues. Ohm was forced to resign from his high-school teaching position and he lived in poverty and shame until he accepted a position at Nüremberg in 1833 and although this gave him the title of professor, it was still not the university post for which he had strived all his life.

Ohm the Genius! the Mozart of Electricity ...

Ohm and corrosion monitoring

Ohm’s main interest was current electricity, which had recently been advanced by Alessandro Volta’s invention of the battery. Ohm made only a modest living and as a result his experimental equipment was primitive. Despite this, he made his own metal wire, producing a range of thickness and lengths of remarkable consistent quality. The nine years he spent at the Jesuit’s college, he did considerable experimental research on the nature of electric circuits. He took considerable pains to be brutally accurate with every detail of his work. In 1827, he was able to show from his experiments that there was a simple relationship between resistance, current and voltage.

Ohm was afraid that the purely experimental basis of his work would undermine the importance of his discovery. He tried to state his law theoretically but his rambling mathematically proofs made him an object of ridicule. In the years that followed, Ohm lived in poverty, tutoring privately in Berlin. He would receive no credit for his findings until he was made director of the Polytechnic School of Nüremberg in 1833. In 1841, the Royal Society in London recognized the significance of his discovery and awarded him the Copley medal. The following year, they admitted him as a member. In 1849, just 5 years before his death, Ohm’s lifelong dream was realized when he was given a professorship of Experimental Physics at the University of Munich. On July 7th,1854 he passed away in Munich, at the age of 65.

This belated recognition was welcome but there remains the question of why someone who today is a household name for his important contribution struggled for so long to gain acknowledgement. This may have no simple explanation but rather be the result of a number of different contributory factors. One factor may have been the inwardness of Ohm's character while another was certainly his mathematical approach to topics which at that time were studied in his country a non-mathematical way. There was undoubtedly also personal disputes with the men in power which did Ohm no good at all. He certainly did not find favor with Johannes Schultz who was an influential figure in the ministry of education in Berlin, and with Georg Friedrich Pohl, a professor of physics in that city.

Electricity was not the only topic on which Ohm undertook research, and not the only topic in which he ended up in controversy. In 1843 he stated the fundamental principle of physiological acoustics, concerned with the way in which one hears combination tones. However the assumptions which he made in his mathematical derivation were not totally justified and this resulted in a bitter dispute with the physicist August Seebeck. He succeeded in discrediting Ohm's hypothesis and Ohm had to acknowledge his error.

Michael Faraday (1791-1867)

Michael Faraday, the discoverer of electro-magnetic induction, electro-magnetic rotations, the magneto-optical effect, diamagnetism, field theory and much else besides, was born in Newington Butts (the area of London now known as the Elephant and Castle) on 22 September 1791. In 1805 at the age of fourteen Faraday was apprenticed as a bookbinder to George Riebau of Blandford Street. During his seven year apprenticeship Faraday developed his interest in science and in particular chemistry. He was there able to perform chemical experiments and built his own electro-static machine.

Faraday and corrosion monitoring

But, more importantly, Faraday joined the City Philosophical Society in 1810. In this society, which was devoted to self-improvement, a group of young men met every week to hear lectures on scientific topics and to discuss scientific matters. This is where Faraday would give his first scientific lectures.

For most of the 1810s and 1820s he worked under Davy's replacement as Professor of Chemistry, William Thomas Brande. However, between October 1813 and April 1815, he accompanied Davy, as his assistant, on a scientific tour of the Continent. Davy had been given a passport by Napoleon for himself, his wife, her maid and a valet. Faraday, very reluctantly, agreed to also perform this latter role. On the tour they visited Paris, Italy where they met the aged Volta, visited Vesuvius and Davy was able to decompose a diamond into carbon by using the Duke of Tuscany's great lens, Switzerland and Southern Germany.

The year was also the one when he made his first major contribution to natural knowledge. In 1820 the Danish natural philosopher Hans Christian Oersted had discovered electro-magnetism. This he announced in a paper written in Latin, but was quickly translated into the major scientific languages of Europe. It was immediately evident that Oersted had made a major discovery. What was clear was that Oersted had opened up a major field of scientific enquiry which was exploited by savants all over Europe. Faraday was part of this effort and on 3 and 4 September 1821 in his basement laboratory at the Royal Institution, he undertook a set of experiments which culminated in his discovery of electro-magnetic rotation - the principle behind the electric motor.

In the ensuing decade following this discovery, Faraday's opportunity for doing original research was severely circumscribed by his lecturing activiites, although he was able to liquefy chlorine in 1823 and discover bicarbuet of hydrogen, later renamed benzene by Eilhard Mitscherlich, in 1825. It was not until nearly ten years to the day after his discovery of electro-magnetic rotations that Faraday was able to resume his work on electro-magnetism, when he discovered on 29 August 1831, electro-magnetic induction. This is the principle behind the electric transformer and generator. It was this discovery, more than any other, that allowed electricity to be turned, during the nineteenth century, from a scientific curiosity into a powerful technology.

During the remainder of the 1830s Faraday worked on developing his ideas on electricity. He enunciated a new theory of electro-chemical action between 1832 and 1834 one of the results of which was that he coined many of the words now so familiar - electrode, electrolyte, anode, cathode and ion to name but five. In the later half of the 1830s Faraday worked on a new theory of static electricity and electrical induction. This work led him to reject the traditional theory that electricity was an imponderable fluid or fluids. Instead he proposed that electricity was a form of force that passed from particle to particle of matter.

Between 1830 and 1851 Faraday was Professor of Chemistry at the Royal Military Academy in Woolwich. During his tenure generations of officers of the Royal Engineers and Royal Artillery learnt their chemistry from him. He died at Hampton Court on 25 August 1867 and was buried in the Sandemanian plot in Highgate Cemetery five days later.

Michael Faraday, the son of a blacksmith

Michael Faraday, the son of a blacksmith, was born in London in 1791. He was apprenticed to a bookbinder and this contact with books gave him a love of reading. After becoming interested in science, Faraday applied to Humphry Davy for a job. In 1813 Faraday became his temporary assistant and spent the next 18 months touring Europe while during Davy's investigations into his theory of volcanic action.

Davy gave Faraday a valuable scientific education and also introduced him to important scientists in Europe. After Humphry Davy retired in 1827, Faraday replaced him as professor of chemistry at the Royal Institution. Faraday began to publish details of his research including condensation of gases, optical deceptions and the isolation of benzene from gas oils.

Faraday's greatest contribution to science was in the field of electricity. In 1821 he began experimenting with electromagnetism and by demonstrating the conversion of electrical energy into motive force, invented the electric motor. In 1831 Faraday discovered the induction of electric currents and made the first dynamo. In 1837 he demonstrated that electrostatic force consists of a field of curved lines of force, and conceived a specific inductive capacity. This led to Faraday being able to develop his theories on light and gravitational systems.

The government recognized his contribution to science by granting him a pension and giving him a house in Hampton Court. However, Faraday was unwilling to use his scientific knowledge to help military action and in 1853 refused to help develop poison gases to be used in the Crimean War. Michael Faraday died in 1867.

In 1813 Michael Faraday wrote about the lectures by Humphry Davy.

Sir H. Davy proceeded to make a few observations on the connections of science with other parts of polished and social life. Here it would be impossible for me to follow him. I should merely injure and destroy the beautiful and sublime observations that fell from his lips. He spoke in the most energetic and luminous manner of the Advancement of the Arts and Sciences. Of the connection that had always existed between them and other parts of a Nation's economy. During the whole of these observations his delivery was easy, his diction elegant, his tone good and his sentiments sublime.

Humphry Davy,letter to the royal institution in 1813

I have the honour to inform you that I have found a person who is desirous to occupy the situation in the Institution lately filled by William Payne. His name is Michael Faraday. He is a youth of twenty-two years of age. As far as I have been able to ascertain, he appears well fitted for the situation. His habits seem good, his disposition is active and cheerful, his manner intelligent. He is willing to engage himself on the same terms as those given to Mr. Payne at the time of quitting the Institution.

Michael Faraday wrote a letter to Benjamin Abbott while paying a visit to Rome (11th June, 1813)

A Lecturer should appear easy and collected, undaunted and unconcerned his thoughts about him and his mind clear and free for the contemplation and description of his subject. His action should not be hasty and violent but slow easy and natural consisting principally in changes of the posture of the body in order to avoid the air of stiffness or sameness that would otherwise be unavoidable.

Michael Faraday wrote a letter to Benjamin Abbott while paying a visit to Rome (1st May, 1814)

The things (in Rome) would affect anyone, and that mind must be dull indeed that is not urged to think & think again on these astonishing remains of the Romans when they appear in sight at every corner. The two things here most striking are the Coliseum and St. Peter's, and one is not more worthy of the ancients than the other is of the moderns. The Coliseum is a mighty ruin & indeed so is Rome & so are the Romans, & it is almost impossible to conceive how the hardy warlike race which conquered the globe has degenerated into modern, effeminate, idle Italians. St. Peter's appears to have been erected on the plan of some fairy tale, for every luxury, every ornament and every embellishment & species of embellishment have been employed in its erection. Its size is mighty, it is mountainous, its architecture elegant, its materials costly.

Michael Faraday, Address delivered at the Commemoration of the Centenary of the Birth of Dr Priestley (1833)

Dr. Priestley had that freedom of mind, and that independence of dogma and of preconceived notions, by which men are so often bowed down and carried forward from fallacy to fallacy, their eyes not being opened to see what that fallacy is. I am very anxious at this time to exhort you all, - as I trust you all are pursuers of science, - to attend to these things; for DR Priestley made his great discoveries mainly in consequence of his having a mind which could be easily moved from what it had held to the reception of new thoughts and notions; and I will venture to say that all his discoveries followed from the facility with which he could leave a preconceived idea.

Friedrich Von Raumer, England in 1835 (1836)

He (Michael Faraday) speaks with ease and freedom, but not with a gossipy, unequal tone, alternately inaudible and bawling, as some very learned professors do; he delivers himself with clearness, precision and ability. Moreover, he speaks his language in a manner which confirmed me in a secret suspicion that I had, that a number of Englishmen speak it very badly.

Charles Schoenbein, letter to Michael Faraday (4th April, 1840)

Please do not to overwork yourself and to manage a little your mental and physical forces, for your health and life are most precious to your friends in particular and to the scientific world at large. We cannot yet spare you and you must continue to be our leader for many years to come. You ought to listen a little to the entreaties of your friends and to grant to your mind and body some little rest. I am sure Mrs. Faraday will be of my opinion and confident she will not cease reminding you of it.

Michael Faraday, letter to Charles Schoenbein (13th November, 1845)

At present I have scarcely a moment to spare for any thing but work. I happen to have discovered a direct relation between magnetism & light also Electricity & light - and the field it opens is so large & I think rich that I naturally wish to look at it first. I actually have no time to tell you what the thing is - for I now see no one & do no thing but just work. My head became giddy & I have therefore come to this place (Brighton) but still I bring my work with me. When I can catch time I will tell you more.

Michael Faraday as a discover

Underneath his sweetness and gentleness was the heat of a volcano. He was a man of excitable and fiery nature; but through high self-discipline he had converted the fire into a central glow and motive power of life, instead of permitting it to waste itself in useless passion. Faraday was not slow to anger, but he completely ruled his own spirit, and thus, though he took no cities, he captivated all hearts.

Jane Pollack, Michael Faraday, St. Paul's Magazine (1870)

It was an irresistible eloquence which compelled attention and invited upon sympathy. There was a gleaming in his eyes which no painter could copy, and which no poet could describe. Their radiance seemed to send a strange light into the very heart of his congregation, and when he spoke, it was felt that the stir of his voice and the fervour of his words could belong only to the owner of those kindling eyes. His thought was rapid and made its way in new phrases. His enthusiasm seemed to carry him to the point of ecstasy when he expatiated on the beauties of Nature, and when he lifted the veil from her deep mysteries. His body then took motion from his mind; his hair streamed out from his head; his hands were full of nervous action; his light, lithe body seemed to quiver with its eager life. His audience took fire with him, and every face was flushed.

Alessandro Volta (1745-1827)

A century and a half after Galileo's death, something of scientific importance was to develop in Italy. Volta, a former high school physics teacher, found that it was the presence of two dissimilar metals, not the frog leg, that was critical. In 1800, after extensive experimentation, he developed the voltaic pile. The original voltaic pile consisted of a pile of zinc and silver discs and between alternate discs, a piece of cardboard that had been soaked in saltwater. A wire connecting the bottom zinc disc to the top silver disc could produce repeated sparks. No frogs were injured in the production of a voltaic pile.

Types of electromagnetics fields

However, regarding Galvani's biological experiments, Volta effectively rejected the idea of an "animal electric fluid". The Galvani vs. Volta debate was one of the most interesting episodes in the history of science, and was devoid of personal animosity, because Galvani and Volta were both gentleman and friends, and also had high scientific principles. In fact, Volta, who generously coined the term galvanism, wrote that Galvani's work "contained one of the most beautiful and most surprising discoveries." Upon demonstrating the workings of the voltaic pile to the French Academy of Science, he was made into a count of Lombardy by Napoleon Bonaparte, who had dominated that part of Italy.

The emperor of Austria made him director of the philosophical faculty at the University of Padua in 1815, 12 years before the day he was to die. The volt as we hear today, was named after Alessandro Volta in 1881 in honor and memory of him.

In a nutshell

Volta invented the so-called Volta’s pile (or voltaic pile); the electrophorus; an electric condenser; and the voltaic cell. The volt, a unit of electrical measurement, is named for Volta.

Main points:

1775 Volta devised the electrophorus, a device that produced a static electric charge.

1777 he studied the chemistry of gases, discovered methane

1779 he became professor of physics at the University of Pavia

1794 Volta married Teresa Peregrini, daughter of Count Peregrini; the couple had three sons.

1800 he developed the so-called voltaic pile, a forerunner of the electric battery

1810 In honor of his work in the field of electricity, Napoleon made him a count

1815 the Emperor of Austria named him a professor of philosophy at Padova.

1816 Volta's works were published in five volumes in Florence

1881 an important electrical unit, the volt, was named in his honor.

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Thomas Edison

Thomas Edison Born on February 11, 1847 in Milan, Ohio; the seventh and last child of Samuel and Nancy Edison. When he was seven his family moved to Port Huron, Michigan and Edison lived there until he struck out on his own at the age of sixteen. He had very little formal education as a child, attending school only for a few months. He was taught reading, writing, and arithmetic by his mother, but was always a very curious child and taught himself much by reading on his own. This belief in self-improvement remained throughout his life.