Michael Faraday FRS (/ˈfærədeɪ, -di/; 22 September 1791 – 25 August 1867) was a British scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, diamagnetism and electrolysis.
Although Faraday received little formal education, he was one of the most influential scientists in history. It was by his research on the magnetic field around a conductor carrying a direct current that Faraday established the basis for the concept of the electromagnetic field in physics. Faraday also established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena. He similarly discovered the principles of electromagnetic induction and diamagnetism, and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became practical for use in technology.
As a chemist, Faraday discovered benzene, investigated the clathrate hydrate of chlorine, invented an early form of the Bunsen burner and the system of oxidation numbers, and popularised terminology such as "anode", "cathode", "electrode" and "ion". Faraday ultimately became the first and foremost Fullerian Professor of Chemistry at the Royal Institution, a lifetime position.
Faraday was an excellent experimentalist who conveyed his ideas in clear and simple language; his mathematical abilities, however, did not extend as far as trigonometry and were limited to the simplest algebra. James Clerk Maxwell took the work of Faraday and others and summarized it in a set of equations which is accepted as the basis of all modern theories of electromagnetic phenomena. On Faraday's uses of lines of force, Maxwell wrote that they show Faraday "to have been in reality a mathematician of a very high order – one from whom the mathematicians of the future may derive valuable and fertile methods." The SI unit of capacitance is named in his honour: the farad.
Albert Einstein kept a picture of Faraday on his study wall, alongside pictures of Isaac Newton and James Clerk Maxwell. Physicist Ernest Rutherford stated, "When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time."
Michael Faraday, 1842, by Thomas Phillips
|Born||22 September 1791|
Newington Butts, England
|Died||25 August 1867 (aged 75)|
Hampton Court, Middlesex, England
|Known for||Faraday's law of induction|
Faraday's laws of electrolysis
Lines of force
|Awards||Royal Medal (1835 and 1846)|
Copley Medal (1832 and 1838)
Rumford Medal (1846)
Albert Medal (1866)
William Thomas Brande
Michael Faraday was born on 22 September 1791 in Newington Butts, which is now part of the London Borough of Southwark but was then a suburban part of Surrey. His family was not well off. His father, James, was a member of the Glassite sect of Christianity. James Faraday moved his wife and two children to London during the winter of 1790 from Outhgill in Westmorland, where he had been an apprentice to the village blacksmith. Michael was born in the autumn of that year. The young Michael Faraday, who was the third of four children, having only the most basic school education, had to educate himself.
At the age of 14 he became an apprentice to George Riebau, a local bookbinder and bookseller in Blandford Street. During his seven-year apprenticeship Faraday read many books, including Isaac Watts's The Improvement of the Mind, and he enthusiastically implemented the principles and suggestions contained therein. He also developed an interest in science, especially in electricity. Faraday was particularly inspired by the book Conversations on Chemistry by Jane Marcet.
In 1812, at the age of 20 and at the end of his apprenticeship, Faraday attended lectures by the eminent English chemist Humphry Davy of the Royal Institution and the Royal Society, and John Tatum, founder of the City Philosophical Society. Many of the tickets for these lectures were given to Faraday by William Dance, who was one of the founders of the Royal Philharmonic Society. Faraday subsequently sent Davy a 300-page book based on notes that he had taken during these lectures. Davy's reply was immediate, kind, and favourable. In 1813, when Davy damaged his eyesight in an accident with nitrogen trichloride, he decided to employ Faraday as an assistant. Coincidentally one of the Royal Institution's assistants, John Payne, was sacked and Sir Humphry Davy had been asked to find a replacement; thus he appointed Faraday as Chemical Assistant at the Royal Institution on 1 March 1813. Very soon Davy entrusted Faraday with the preparation of nitrogen trichloride samples, and they both were injured in an explosion of this very sensitive substance.
In the class-based English society of the time, Faraday was not considered a gentleman. When Davy set out on a long tour of the continent in 1813–15, his valet did not wish to go, so instead, Faraday went as Davy's scientific assistant and was asked to act as Davy's valet until a replacement could be found in Paris. Faraday was forced to fill the role of valet as well as assistant throughout the trip. Davy's wife, Jane Apreece, refused to treat Faraday as an equal (making him travel outside the coach, eat with the servants, etc.), and made Faraday so miserable that he contemplated returning to England alone and giving up science altogether. The trip did, however, give him access to the scientific elite of Europe and exposed him to a host of stimulating ideas.
Faraday married Sarah Barnard (1800–1879) on 12 June 1821. They met through their families at the Sandemanian church, and he confessed his faith to the Sandemanian congregation the month after they were married. They had no children.
Faraday was a devout Christian; his Sandemanian denomination was an offshoot of the Church of Scotland. Well after his marriage, he served as deacon and for two terms as an elder in the meeting house of his youth. His church was located at Paul's Alley in the Barbican. This meeting house relocated in 1862 to Barnsbury Grove, Islington; this North London location was where Faraday served the final two years of his second term as elder prior to his resignation from that post. Biographers have noted that "a strong sense of the unity of God and nature pervaded Faraday's life and work."
In June 1832, the University of Oxford granted Faraday a Doctor of Civil Law degree (honorary). During his lifetime, he was offered a knighthood in recognition for his services to science, which he turned down on religious grounds, believing that it was against the word of the Bible to accumulate riches and pursue worldly reward, and stating that he preferred to remain "plain Mr Faraday to the end". Elected a member of the Royal Society in 1824, he twice refused to become President. He became the first Fullerian Professor of Chemistry at the Royal Institution in 1833.
In 1832, Faraday was elected a Foreign Honorary Member of the American Academy of Arts and Sciences. He was elected a foreign member of the Royal Swedish Academy of Sciences in 1838, and was one of eight foreign members elected to the French Academy of Sciences in 1844. In 1849 he was elected as associated member to the Royal Institute of the Netherlands, which two years later became the Royal Netherlands Academy of Arts and Sciences and he was subsequently made foreign member.
Faraday suffered a nervous breakdown in 1839 but eventually returned to his investigations into electromagnetism. In 1848, as a result of representations by the Prince Consort, Faraday was awarded a grace and favour house in Hampton Court in Middlesex, free of all expenses and upkeep. This was the Master Mason's House, later called Faraday House, and now No. 37 Hampton Court Road. In 1858 Faraday retired to live there.
Having provided a number of various service projects for the British government, when asked by the government to advise on the production of chemical weapons for use in the Crimean War (1853–1856), Faraday refused to participate citing ethical reasons.
Faraday died at his house at Hampton Court on 25 August 1867, aged 75. He had some years before turned down an offer of burial in Westminster Abbey upon his death, but he has a memorial plaque there, near Isaac Newton's tomb. Faraday was interred in the dissenters' (non-Anglican) section of Highgate Cemetery.
Faraday's earliest chemical work was as an assistant to Humphry Davy. Faraday was specifically involved in the study of chlorine; he discovered two new compounds of chlorine and carbon. He also conducted the first rough experiments on the diffusion of gases, a phenomenon that was first pointed out by John Dalton. The physical importance of this phenomenon was more fully revealed by Thomas Graham and Joseph Loschmidt. Faraday succeeded in liquefying several gases, investigated the alloys of steel, and produced several new kinds of glass intended for optical purposes. A specimen of one of these heavy glasses subsequently became historically important; when the glass was placed in a magnetic field Faraday determined the rotation of the plane of polarisation of light. This specimen was also the first substance found to be repelled by the poles of a magnet.
Faraday invented an early form of what was to become the Bunsen burner, which is in practical use in science laboratories around the world as a convenient source of heat. Faraday worked extensively in the field of chemistry, discovering chemical substances such as benzene (which he called bicarburet of hydrogen) and liquefying gases such as chlorine. The liquefying of gases helped to establish that gases are the vapours of liquids possessing a very low boiling point and gave a more solid basis to the concept of molecular aggregation. In 1820 Faraday reported the first synthesis of compounds made from carbon and chlorine, C2Cl6 and C2Cl4, and published his results the following year. Faraday also determined the composition of the chlorine clathrate hydrate, which had been discovered by Humphry Davy in 1810. Faraday is also responsible for discovering the laws of electrolysis, and for popularizing terminology such as anode, cathode, electrode, and ion, terms proposed in large part by William Whewell.
Faraday was the first to report what later came to be called metallic nanoparticles. In 1847 he discovered that the optical properties of gold colloids differed from those of the corresponding bulk metal. This was probably the first reported observation of the effects of quantum size, and might be considered to be the birth of nanoscience.
Faraday is best known for his work regarding electricity and magnetism. His first recorded experiment was the construction of a voltaic pile with seven ha'penny coins, stacked together with seven disks of sheet zinc, and six pieces of paper moistened with salt water. With this pile he decomposed sulfate of magnesia (first letter to Abbott, 12 July 1812).
In 1821, soon after the Danish physicist and chemist Hans Christian Ørsted discovered the phenomenon of electromagnetism, Davy and British scientist William Hyde Wollaston tried, but failed, to design an electric motor. Faraday, having discussed the problem with the two men, went on to build two devices to produce what he called "electromagnetic rotation". One of these, now known as the homopolar motor, caused a continuous circular motion that was engendered by the circular magnetic force around a wire that extended into a pool of mercury wherein was placed a magnet; the wire would then rotate around the magnet if supplied with current from a chemical battery. These experiments and inventions formed the foundation of modern electromagnetic technology. In his excitement, Faraday published results without acknowledging his work with either Wollaston or Davy. The resulting controversy within the Royal Society strained his mentor relationship with Davy and may well have contributed to Faraday's assignment to other activities, which consequently prevented his involvement in electromagnetic research for several years.
From his initial discovery in 1821, Faraday continued his laboratory work, exploring electromagnetic properties of materials and developing requisite experience. In 1824, Faraday briefly set up a circuit to study whether a magnetic field could regulate the flow of a current in an adjacent wire, but he found no such relationship. This experiment followed similar work conducted with light and magnets three years earlier that yielded identical results. During the next seven years, Faraday spent much of his time perfecting his recipe for optical quality (heavy) glass, borosilicate of lead, which he used in his future studies connecting light with magnetism. In his spare time, Faraday continued publishing his experimental work on optics and electromagnetism; he conducted correspondence with scientists whom he had met on his journeys across Europe with Davy, and who were also working on electromagnetism. Two years after the death of Davy, in 1831, he began his great series of experiments in which he discovered electromagnetic induction, recording in his laboratory diary on 28 October 1831 he was; "making many experiments with the great magnet of the Royal Society".
Faraday's breakthrough came when he wrapped two insulated coils of wire around an iron ring, and found that upon passing a current through one coil a momentary current was induced in the other coil. This phenomenon is now known as mutual induction. The iron ring-coil apparatus is still on display at the Royal Institution. In subsequent experiments, he found that if he moved a magnet through a loop of wire an electric current flowed in that wire. The current also flowed if the loop was moved over a stationary magnet. His demonstrations established that a changing magnetic field produces an electric field; this relation was modelled mathematically by James Clerk Maxwell as Faraday's law, which subsequently became one of the four Maxwell equations, and which have in turn evolved into the generalization known today as field theory. Faraday would later use the principles he had discovered to construct the electric dynamo, the ancestor of modern power generators and the electric motor.
In 1832, he completed a series of experiments aimed at investigating the fundamental nature of electricity; Faraday used "static", batteries, and "animal electricity" to produce the phenomena of electrostatic attraction, electrolysis, magnetism, etc. He concluded that, contrary to the scientific opinion of the time, the divisions between the various "kinds" of electricity were illusory. Faraday instead proposed that only a single "electricity" exists, and the changing values of quantity and intensity (current and voltage) would produce different groups of phenomena.
Near the end of his career, Faraday proposed that electromagnetic forces extended into the empty space around the conductor. This idea was rejected by his fellow scientists, and Faraday did not live to see the eventual acceptance of his proposition by the scientific community. Faraday's concept of lines of flux emanating from charged bodies and magnets provided a way to visualize electric and magnetic fields; that conceptual model was crucial for the successful development of the electromechanical devices that dominated engineering and industry for the remainder of the 19th century.
Faraday also discovered that the plane of polarization of linearly polarized light can be rotated by the application of an external magnetic field aligned with the direction in which the light is moving. This is now termed the Faraday effect. In Sept 1845 he wrote in his notebook, "I have at last succeeded in illuminating a magnetic curve or line of force and in magnetising a ray of light".
Later on in his life, in 1862, Faraday used a spectroscope to search for a different alteration of light, the change of spectral lines by an applied magnetic field. The equipment available to him was, however, insufficient for a definite determination of spectral change. Pieter Zeeman later used an improved apparatus to study the same phenomenon, publishing his results in 1897 and receiving the 1902 Nobel Prize in Physics for his success. In both his 1897 paper and his Nobel acceptance speech, Zeeman made reference to Faraday's work.
In his work on static electricity, Faraday's ice pail experiment demonstrated that the charge resided only on the exterior of a charged conductor, and exterior charge had no influence on anything enclosed within a conductor. This is because the exterior charges redistribute such that the interior fields emanating from them cancel one another. This shielding effect is used in what is now known as a Faraday cage.
Faraday had a long association with the Royal Institution of Great Britain. He was appointed Assistant Superintendent of the House of the Royal Institution in 1821. He was elected a member of the Royal Society in 1824. In 1825, he became Director of the Laboratory of the Royal Institution. Six years later, in 1833, Faraday became the first Fullerian Professor of Chemistry at the Royal Institution of Great Britain, a position to which he was appointed for life without the obligation to deliver lectures. His sponsor and mentor was John 'Mad Jack' Fuller, who created the position at the Royal Institution for Faraday.
Beyond his scientific research into areas such as chemistry, electricity, and magnetism at the Royal Institution, Faraday undertook numerous, and often time-consuming, service projects for private enterprise and the British government. This work included investigations of explosions in coal mines, being an expert witness in court, and along with two engineers from Chance Brothers c.1853, the preparation of high-quality optical glass, which was required by Chance for its lighthouses. In 1846, together with Charles Lyell, he produced a lengthy and detailed report on a serious explosion in the colliery at Haswell, County Durham, which killed 95 miners. Their report was a meticulous forensic investigation and indicated that coal dust contributed to the severity of the explosion. The report should have warned coal owners of the hazard of coal dust explosions, but the risk was ignored for over 60 years until the Senghenydd Colliery Disaster of 1913.
As a respected scientist in a nation with strong maritime interests, Faraday spent extensive amounts of time on projects such as the construction and operation of lighthouses and protecting the bottoms of ships from corrosion. His workshop still stands at Trinity Buoy Wharf above the Chain and Buoy Store, next to London's only lighthouse where he carried out the first experiments in electric lighting for lighthouses.
Faraday was also active in what would now be called environmental science, or engineering. He investigated industrial pollution at Swansea and was consulted on air pollution at the Royal Mint. In July 1855, Faraday wrote a letter to The Times on the subject of the foul condition of the River Thames, which resulted in an often-reprinted cartoon in Punch. (See also The Great Stink).
Faraday assisted with the planning and judging of exhibits for the Great Exhibition of 1851 in London. He also advised the National Gallery on the cleaning and protection of its art collection, and served on the National Gallery Site Commission in 1857.
Education was another of Faraday's areas of service; he lectured on the topic in 1854 at the Royal Institution, and in 1862 he appeared before a Public Schools Commission to give his views on education in Great Britain. Faraday also weighed in negatively on the public's fascination with table-turning, mesmerism, and seances, and in so doing chastised both the public and the nation's educational system.
Before his famous Christmas lectures, Faraday delivered chemistry lectures for the City Philosophical Society from 1816 to 1818 in order to refine the quality of his lectures. Between 1827 and 1860 at the Royal Institution in London, Faraday gave a series of nineteen Christmas lectures for young people, a series which continues today. The objective of Faraday's Christmas lectures was to present science to the general public in the hopes of inspiring them and generating revenue for the Royal Institution. They were notable events on the social calendar among London's gentry. Over the course of several letters to his close friend Benjamin Abbott, Faraday outlined his recommendations on the art of lecturing: Faraday wrote "a flame should be lighted at the commencement and kept alive with unremitting splendour to the end". His lectures were joyful and juvenile, he delighted in filling soap bubbles with various gasses (in order to determine whether or not they are magnetic) in front of his audiences and marveled at the rich colors of polarized lights, but the lectures were also deeply philosophical. In his lectures he urged his audiences to consider the mechanics of his experiments: "you know very well that ice floats upon water ... Why does the ice float? Think of that, and philosophise". His subjects consisted of Chemistry and Electricity, and included: 1841 The Rudiments of Chemistry, 1843 First Principles of Electricity, 1848 The Chemical History of a Candle, 1851 Attractive Forces, 1853 Voltaic Electricity, 1854 The Chemistry of Combustion, 1855 The Distinctive Properties of the Common Metals, 1857 Static Electricity, 1858 The Metallic Properties, 1859 The Various Forces of Matter and their Relations to Each Other.
A statue of Faraday stands in Savoy Place, London, outside the Institution of Engineering and Technology. Also in London, the Michael Faraday Memorial, designed by brutalist architect Rodney Gordon and completed in 1961, is at the Elephant & Castle gyratory system, near Faraday's birthplace at Newington Butts. Faraday School is located on Trinity Buoy Wharf where his workshop still stands above the Chain and Buoy Store, next to London's only lighthouse.
Faraday Gardens is a small park in Walworth, London, not far from his birthplace at Newington Butts. This park lies within the local council ward of Faraday in the London Borough of Southwark. Michael Faraday Primary school is situated on the Aylesbury Estate in Walworth.
A building at London South Bank University, which houses the institute's electrical engineering departments is named the Faraday Wing, due to its proximity to Faraday's birthplace in Newington Butts. A hall at Loughborough University was named after Faraday in 1960. Near the entrance to its dining hall is a bronze casting, which depicts the symbol of an electrical transformer, and inside there hangs a portrait, both in Faraday's honour. An eight-story building at the University of Edinburgh's science & engineering campus is named for Faraday, as is a recently built hall of accommodation at Brunel University, the main engineering building at Swansea University, and the instructional and experimental physics building at Northern Illinois University. The former UK Faraday Station in Antarctica was named after him.
Streets named for Faraday can be found in many British cities (e.g., London, Fife, Swindon, Basingstoke, Nottingham, Whitby, Kirkby, Crawley, Newbury, Swansea, Aylesbury and Stevenage) as well as in France (Paris), Germany (Berlin-Dahlem, Hermsdorf), Canada (Quebec; Deep River, Ontario; Ottawa, Ontario), and the United States (Reston, Virginia).
A Royal Society of Arts blue plaque, unveiled in 1876, commemorates Faraday at 48 Blandford Street in London's Marylebone district. From 1991 until 2001, Faraday's picture featured on the reverse of Series E £20 banknotes issued by the Bank of England. He was portrayed conducting a lecture at the Royal Institution with the magneto-electric spark apparatus. In 2002, Faraday was ranked number 22 in the BBC's list of the 100 Greatest Britons following a UK-wide vote.
The Faraday Institute for Science and Religion derives its name from the scientist, who saw his faith as integral to his scientific research. The logo of the Institute is also based on Faraday's discoveries. It was created in 2006 by a $2,000,000 grant from the John Templeton Foundation to carry out academic research, to foster understanding of the interaction between science and religion, and to engage public understanding in both these subject areas.
Faraday's life and contributions to electromagnetics was the principal topic of the tenth episode, titled "The Electric Boy", of the 2014 American science documentary series, Cosmos: A Spacetime Odyssey, which was broadcast on Fox and the National Geographic Channel.
In honor and remembrance of his great scientific contributions, several institutions have created prizes and awards in his name. This include:
Faraday's books, with the exception of Chemical Manipulation, were collections of scientific papers or transcriptions of lectures. Since his death, Faraday's diary has been published, as have several large volumes of his letters and Faraday's journal from his travels with Davy in 1813–1815.
Faraday made some attempt to explain what was causing the vivid coloration in his gold mixtures, saying that known phenomena seemed to indicate that a mere variation in the size of gold particles gave rise to a variety of resultant colors.
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). The word was coined by William Whewell at the request of the scientist Michael Faraday from two Greek words: elektron, meaning amber (from which the word electricity is derived), and hodos, a way.The electrophore, invented by Johan Wilcke, was an early version of an electrode used to study static electricity.Electromagnetic induction
Electromagnetic or magnetic induction is the production of an electromotive force (i.e., voltage) across an electrical conductor in a changing magnetic field.
Michael Faraday is generally credited with the discovery of induction in 1831, and James Clerk Maxwell mathematically described it as Faraday's law of induction. Lenz's law describes the direction of the induced field. Faraday's law was later generalized to become the Maxwell–Faraday equation, one of the four Maxwell equations in his theory of electromagnetism.
Electromagnetic induction has found many applications, including electrical components such as inductors and transformers, and devices such as electric motors and generators.Farad
The farad (symbol: F) is the SI derived unit of electrical capacitance, the ability of a body to store an electrical charge. It is named after the English physicist Michael Faraday.Faraday's law of induction
Faraday's law of induction (shortly called Faraday's law throughout this document) is a basic law of electromagnetism predicting how a magnetic field will interact with an electric circuit to produce an electromotive force (EMF)—a phenomenon called electromagnetic induction. It is the fundamental operating principle of transformers, inductors, and many types of electrical motors, generators and solenoids.The Maxwell–Faraday equation (listed as one of Maxwell's equations) describes the fact that a spatially varying (and also possibly time-varying, depending on how a magnetic field varies in time) electric field always accompanies a time-varying magnetic field, while Faraday's law states that there is EMF (electromotive force, defined as electromagnetic work done on a unit charge when it has traveled one round of a conductive loop) on the conductive loop when the magnetic flux through the surface enclosed by the loop varies in time.
Historically, Faraday's law had been discovered and one aspect of it (transformer EMF) was formulated as the Maxwell–Faraday equation later. Interestingly, the equation of Faraday's law can be derived by the Maxwell–Faraday equation (describing transformer EMF) and the Lorentz force (describing motional EMF). The integral form of the Maxwell–Faraday equation describes only the transformer EMF, while the equation of Faraday's law describes both the transformer EMF and the motional EMF.Faraday's laws of electrolysis
Faraday's laws of electrolysis are quantitative relationships based on the electrochemical research published by Michael Faraday in 1834. They relate the amount of material produced at an electrode during an electrochemical reaction to the total charge passed or, equivalently, the average current and total time.Faraday (crater)
Faraday is a lunar impact crater in the southern highlands of the Moon. It was named after British chemist and physicist Michael Faraday. It lies across the southeast rim of the larger crater Stöfler, and the northwest rim of Faraday forms a wide rampart across the otherwise flat floor of Stöfler. To the east of Faraday is Maurolycus.
The rim of Faraday has been significantly overlain by subsequent impacts, most notably by an overlapping pair across the southwest rim and a crater across the northwest rim. There is a low central ridge running from the southwest to the northeast, nearly dividing the crater floor in half. The floor is nearly flat in the northwest half.Faraday Lectureship Prize
The Faraday Lectureship Prize, previously known simply as the Faraday Lectureship is awarded once every three years (approximately) by the Royal Society of Chemistry for "exceptional contributions to physical or theoretical chemistry". Named after Michael Faraday, the first Faraday Lecture was given in 1869, two years after Faraday's death, by Jean-Baptiste Dumas. As of 2009, the prize was worth £5000, with the recipient also receiving a medal and a certificate. As the name suggests, the recipient also gives a public lecture describing his or her work.Faraday Society
The Faraday Society was a British society for the study of physical chemistry, founded in 1903 and named in honour of Michael Faraday. In 1980, it merged with several similar organisations, including the Chemical Society, the Royal Institute of Chemistry, and the Society for Analytical Chemistry to form the Royal Society of Chemistry which is both a learned society and a professional body. At that time, the Faraday Division became one of six units within the Royal Society of Chemistry.The Faraday Society published Faraday Transactions from 1905 to 1971, when the Royal Society of Chemistry took over the publication.Of particular note were the conferences called Faraday Discussions, which were published under the same name. The publication includes the discussion of the paper as well as the paper itself. At the meeting, more time is given to the discussion than to the author presenting the paper as the audience are given the papers prior to the meeting. These conferences continue to be run by the Royal Society of Chemistry.In addition to its presidents, key figures at the Faraday Society included George Stanley Withers Marlow, Secretary and Editor of the society from 1926–1948,
and his successor Frederick Clifford Tompkins. Tompkins served as Editor until 1977, and as the President of the Faraday Division of the amalgamated Royal Society of Chemistry from 1978-1979.
Prior to the amalgamation, Tompkins received valuable assistance from D. A. Young, who became Editor as of 1977.Faraday cage
A Faraday cage or Faraday shield is an enclosure used to block electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material or in the case of a Faraday cage, by a mesh of such materials. Faraday cages are named after the English scientist Michael Faraday, who invented them in 1836.
A Faraday cage operates because an external electrical field causes the electric charges within the cage's conducting material to be distributed such that they cancel the field's effect in the cage's interior. This phenomenon is used to protect sensitive electronic equipment from external radio frequency interference (RFI). Faraday cages are also used to enclose devices that produce RFI, such as radio transmitters, to prevent their radio waves from interfering with other nearby equipment. They are also used to protect people and equipment against actual electric currents such as lightning strikes and electrostatic discharges, since the enclosing cage conducts current around the outside of the enclosed space and none passes through the interior.
Faraday cages cannot block stable or slowly varying magnetic fields, such as the Earth's magnetic field (a compass will still work inside). To a large degree, though, they shield the interior from external electromagnetic radiation if the conductor is thick enough and any holes are significantly smaller than the wavelength of the radiation. For example, certain computer forensic test procedures of electronic systems that require an environment free of electromagnetic interference can be carried out within a screened room. These rooms are spaces that are completely enclosed by one or more layers of a fine metal mesh or perforated sheet metal. The metal layers are grounded to dissipate any electric currents generated from external or internal electromagnetic fields, and thus they block a large amount of the electromagnetic interference. See also electromagnetic shielding. They provide less attenuation from outgoing transmissions versus incoming: they can shield EMP waves from natural phenomena very effectively, but a tracking device, especially in upper frequencies, may be able to penetrate from within the cage (e.g., some cell phones operate at various radio frequencies so while one cell phone may not work, another one will).
A common misconception is that a Faraday cage provides full blockage or attenuation; this is not true. The reception or transmission of radio waves, a form of electromagnetic radiation, to or from an antenna within a Faraday cage is heavily attenuated or blocked by the cage; however, a Faraday cage has varied attenuation depending on wave form, frequency or distance from receiver/transmitter, and receiver/transmitter power. Near-field high-powered frequency transmissions like HF RFID are more likely to penetrate. Solid cages generally attenuate fields over a broader range of frequencies than mesh cages.Faraday constant
The Faraday constant, denoted by the symbol F and sometimes stylized as ℱ, is named after Michael Faraday. In physics and chemistry, this constant represents the magnitude of electric charge per mole of electrons. It has the currently accepted value
This constant has a simple relation to two other physical constants:
NA is the Avogadro constant (the ratio of the number of particles, N, which is unitless, to the amount of substance, n, in units of moles), and e is the elementary charge or the magnitude of the charge of an electron. This relation holds because the amount of charge of a mole of electrons is equal to the amount of charge in one electron multiplied by the number of electrons in a mole.
One common use of the Faraday constant is electrolysis. One can divide the amount of charge in coulombs by the Faraday constant in order to find the amount (in moles) of the element that has been oxidized.
The value of F was first determined by weighing the amount of silver deposited in an electrochemical reaction in which a measured current was passed for a measured time, and using Faraday's law of electrolysis. Research is continuing into more accurate ways of determining the interrelated constants F, NA, and e.Faraday effect
In physics, the Faraday effect or Faraday rotation is a magneto-optical phenomenon—that is, an interaction between light and a magnetic field in a medium. The Faraday effect causes a rotation of the plane of polarization which is linearly proportional to the component of the magnetic field in the direction of propagation. Formally, it is a special case of gyroelectromagnetism obtained when the dielectric permittivity tensor is diagonal.Discovered by Michael Faraday in 1845, the Faraday effect was the first experimental evidence that light and electromagnetism are related. The theoretical basis of electromagnetic radiation (which includes visible light) was completed by James Clerk Maxwell in the 1860s and 1870s. This effect occurs in most optically transparent dielectric materials (including liquids) under the influence of magnetic fields.
The Faraday effect is caused by left and right circularly polarized waves propagating at slightly different speeds, a property known as circular birefringence. Since a linear polarization can be decomposed into the superposition of two equal-amplitude circularly polarized components of opposite handedness and different phase, the effect of a relative phase shift, induced by the Faraday effect, is to rotate the orientation of a wave's linear polarization.
The Faraday effect has applications in measuring instruments. For instance, the Faraday effect has been used to measure optical rotatory power and for remote sensing of magnetic fields (such as fiber optic current sensors). The Faraday effect is used in spintronics research to study the polarization of electron spins in semiconductors. Faraday rotators can be used for amplitude modulation of light, and are the basis of optical isolators and optical circulators; such components are required in optical telecommunications and other laser applications.Henry (unit)
The henry (symbol: H) is the SI derived unit of electrical inductance. If a current of 1 ampere flowing through the coil produces flux linkage of 1 weber turn, the coil has a self inductance of 1 henry. The unit is named after Joseph Henry (1797–1878), the American scientist who discovered electromagnetic induction independently of and at about the same time as Michael Faraday (1791–1867) in England.Homopolar motor
A homopolar motor is a direct current electric motor with two magnetic poles, the conductors of which always cut unidirectional lines of magnetic flux by rotating a conductor around a fixed axis so that the conductor is at right angles to a static magnetic field. The resulting EMF (Electromotive Force) being continuous in one direction, the homopolar motor needs no commutator but still requires slip rings. The name homopolar indicates that the electrical polarity of the conductor and the magnetic field poles do not change (i.e., that it does not require commutation).Institute of Physics Michael Faraday Medal and Prize
The Michael Faraday Medal and Prize is a prize awarded annually by the Institute of Physics in experimental physics, one of the Institute's Gold medals. The award is made "for outstanding and sustained contributions to experimental physics." The medal is gold and accompanied by a prize of £1000 and a certificate.Michael Faraday Memorial
The Michael Faraday Memorial is a monument to the Victorian scientist Michael Faraday. It is located at Elephant Square in Elephant and Castle, London, England.Royal Institution
The Royal Institution of Great Britain (often abbreviated as the Royal Institution or Ri) is an organisation devoted to scientific education and research, based in London.
It was founded in 1799 by the leading British scientists of the age, including Henry Cavendish and its first president, George Finch, the 9th Earl of Winchilsea. Its foundational principles were diffusing the knowledge of, and facilitating the general introduction of, useful mechanical inventions and improvements, as well as enhancing the application of science to the common purposes of life (including through teaching, courses of philosophical lectures, and experiments).
Much of the Institution's initial funding and the initial proposal for its founding were given by the Society for Bettering the Conditions and Improving the Comforts of the Poor, under the guidance of philanthropist Sir Thomas Bernard and American-born British scientist Sir Benjamin Thompson, Count Rumford. Since its founding it has been based at 21 Albemarle Street in Mayfair. Its Royal Charter was granted in 1800.Royal Institution Christmas Lectures
The Royal Institution Christmas Lectures are a series of lectures on a single topic each, which have been held at the Royal Institution in London each year since 1825, missing 1939–42 because of the Second World War. The lectures present scientific subjects to a general audience, including young people, in an informative and entertaining manner. Michael Faraday initiated the first Christmas Lecture series in 1825. This came at a time when organised education for young people was scarce. Faraday presented a total of nineteen series in all.Royal Society of London Michael Faraday Prize
The Royal Society of London Michael Faraday Prize is awarded for "excellence in communicating science to UK audiences". Named after Michael Faraday, the medal itself is made of silver gilt, and is accompanied by a purse of £2500.The Chemical History of a Candle
The Chemical History of a Candle was the title of a series of six lectures on the chemistry and physics of flames given by Michael Faraday at the Royal Institution in 1848, as part of the series of Christmas lectures for young people founded by Faraday in 1825 and still given there every year.
The lectures described the different zones of combustion in the candle flame and the presence of carbon particles in the luminescent zone. Demonstrations included the production and examination of the properties of hydrogen, oxygen, nitrogen and carbon dioxide gases. An electrolysis cell is demonstrated, first in the electroplating of platinum conductors by dissolved copper, then the production of hydrogen and oxygen gases and their recombination to form water. The properties of water itself are studied, including its expansion while freezing (iron vessels are burst by this expansion), and the relative volume of steam produced when water is vaporized. Techniques for weighing gases on a balance are demonstrated. Atmospheric pressure is described and its effects demonstrated.
Faraday emphasizes that several of the demonstrations and experiments performed in the lectures may be performed by children "at home" and makes several comments regarding proper attention to safety.
The lectures were first printed as a book in 1861.
In 2016, Bill Hammack published a video series of the lectures supplemented by commentary and a companion book. Faraday's ideas are still used as the basis for open teaching about energy in modern primary and secondary schools