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The Man Who Changed Everything: The Life of James Clerk Maxwell
This is the first biography in twenty years of James Clerk Maxwell, one of the greatest scientists of our time and yet a man relatively unknown to the wider public. Approaching science with a freshness unbound by convention or previous expectations, he produced some of the most original scientific thinking of the nineteenth century -- and his discoveries went on to shape the twentieth century.
246 pages, ebook
First published October 17, 2003
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Displaying 1 - 30 of 77 reviews
February 24, 2017
The most important physicist, I didn't really know anything about.
Times Literary Supplement editorial of 1925, preserved in Trinity College Library, sums it up by saying that Maxwell was ‘to physicists, easily the most magical figure of the nineteenth century’.
CAST OF CHARACTERS from the ebook
Maxwell’s relations and close friends
Blackburn, Hugh: Professor of Mathematics at Glasgow University, husband of Jemima.
Blackburn, Jemima (née Wedderburn): James’ cousin, daughter of Isabella Wedderburn
Butler, Henry Montagu: student friend at Cambridge, afterwards Headmaster of Harrow School and, later, Master of Trinity College, Cambridge
Campbell, Lewis: schoolfriend, afterwards Professor of Greek at St Andrews University
Campbell, Robert: younger brother of Lewis
Cay, Charles Hope: James’ cousin, son of Robert
Cay, Jane: James’ aunt, younger sister of Frances Clerk Maxwell
Cay, John: James’ uncle, elder brother of Frances Clerk Maxwell
Cay, Robert: James’ uncle, younger brother of Frances Clerk Maxwell
Cay, William Dyce: James’ cousin, son of Robert
Clerk, Sir George: James’ uncle, elder brother of John Clerk Maxwell
Clerk Maxwell, Frances (née Cay): James’ mother
Clerk Maxwell, John: James’ father
Clerk Maxwell, Katherine Mary (née Dewar): James’ wife
Dewar, Daniel: James’ father-in-law, Principal of Marischal College, Aberdeen
Dunn, Elizabeth (Lizzie) (née Cay): James’ cousin, daughter of Robert Cay
Forbes, James: friend and mentor, Professor of Natural Philosophy at Edinburgh University, afterwards Principal of St Andrew’s University
Hort, Fenton John Anthony: student friend at Cambridge, afterwards a professor at Cambridge
Litchfield, Richard Buckley: student friend at Cambridge, afterwards Secretary of the London Working Men’s College
Mackenzie, Colin: James’ cousin once removed, son of Janet Mackenzie
Mackenzie, Janet (née Wedderburn): James’ cousin, daughter of Isabella Wedderburn
Monro, Cecil James: student friend at Cambridge, afterwards a frequent correspondent with James, particularly on colour vision
Pomeroy, Robert Henry: student friend at Cambridge who joined the Indian Civil Service and died in his 20s during the Indian Mutiny
Tait, Peter Guthrie: schoolfriend, afterwards Professor of Natural Philosophy at Edinburgh University
Thomson, William, later Baron Kelvin of Largs: friend (and mentor in early stages of James’ career), Professor of Natural Philosophy at Glasgow University
Wedderburn, Isabella (née Clerk): James’ aunt, younger sister of John Clerk Maxwell
Wedderburn, James: James’ uncle by marriage, husband of Isabella
Note: The list shows those of Maxwell’s relations and close friends who are mentioned in the narrative, and two more who are included to explain relationships. His work colleagues and associates are not listed here, apart from Forbes, Tait and Thomson.
Times Literary Supplement editorial of 1925, preserved in Trinity College Library, sums it up by saying that Maxwell was ‘to physicists, easily the most magical figure of the nineteenth century’.
CAST OF CHARACTERS from the ebook
Maxwell’s relations and close friends
Blackburn, Hugh: Professor of Mathematics at Glasgow University, husband of Jemima.
Blackburn, Jemima (née Wedderburn): James’ cousin, daughter of Isabella Wedderburn
Butler, Henry Montagu: student friend at Cambridge, afterwards Headmaster of Harrow School and, later, Master of Trinity College, Cambridge
Campbell, Lewis: schoolfriend, afterwards Professor of Greek at St Andrews University
Campbell, Robert: younger brother of Lewis
Cay, Charles Hope: James’ cousin, son of Robert
Cay, Jane: James’ aunt, younger sister of Frances Clerk Maxwell
Cay, John: James’ uncle, elder brother of Frances Clerk Maxwell
Cay, Robert: James’ uncle, younger brother of Frances Clerk Maxwell
Cay, William Dyce: James’ cousin, son of Robert
Clerk, Sir George: James’ uncle, elder brother of John Clerk Maxwell
Clerk Maxwell, Frances (née Cay): James’ mother
Clerk Maxwell, John: James’ father
Clerk Maxwell, Katherine Mary (née Dewar): James’ wife
Dewar, Daniel: James’ father-in-law, Principal of Marischal College, Aberdeen
Dunn, Elizabeth (Lizzie) (née Cay): James’ cousin, daughter of Robert Cay
Forbes, James: friend and mentor, Professor of Natural Philosophy at Edinburgh University, afterwards Principal of St Andrew’s University
Hort, Fenton John Anthony: student friend at Cambridge, afterwards a professor at Cambridge
Litchfield, Richard Buckley: student friend at Cambridge, afterwards Secretary of the London Working Men’s College
Mackenzie, Colin: James’ cousin once removed, son of Janet Mackenzie
Mackenzie, Janet (née Wedderburn): James’ cousin, daughter of Isabella Wedderburn
Monro, Cecil James: student friend at Cambridge, afterwards a frequent correspondent with James, particularly on colour vision
Pomeroy, Robert Henry: student friend at Cambridge who joined the Indian Civil Service and died in his 20s during the Indian Mutiny
Tait, Peter Guthrie: schoolfriend, afterwards Professor of Natural Philosophy at Edinburgh University
Thomson, William, later Baron Kelvin of Largs: friend (and mentor in early stages of James’ career), Professor of Natural Philosophy at Glasgow University
Wedderburn, Isabella (née Clerk): James’ aunt, younger sister of John Clerk Maxwell
Wedderburn, James: James’ uncle by marriage, husband of Isabella
Note: The list shows those of Maxwell’s relations and close friends who are mentioned in the narrative, and two more who are included to explain relationships. His work colleagues and associates are not listed here, apart from Forbes, Tait and Thomson.
May 11, 2016
Maxwell was perhaps the greatest physicist of the 19th century. Every civilized person should know that he formulated the (relativistically-correct!) field equations for electromagnetism. What I hadn't realized was that he practically had to invent vector calculus himself -- "div, grad, curl and all that' are substantially Maxwell's handiwork. He also made huge contributions to statistical mechanics and many other fields -- he showed that Saturn's rings could only be stable if they were composed of small solid particles, instead of being liquid or solid. He also was the first person to really understand the color well enough to explain why there are different primary colors for pigment and light.
The part that was interesting about the book, though, was the portrayal of Maxwell the man. Unlike many scientists, he was a thoroughly admirable person -- "a perfect Christian gentleman" as his contemporaries put it. Friendly, thoughtful, caring, literary, and the object of near-universal admiration.
He had a long correspondence by postcard with two other Scottish physicists (Tait and William Thompson). Thomson was T, Tait was T', and some other scientist they didn't respect was T'' --because he was a second-order quantity. Apparently nerd humor has not improved with time.
The part that was interesting about the book, though, was the portrayal of Maxwell the man. Unlike many scientists, he was a thoroughly admirable person -- "a perfect Christian gentleman" as his contemporaries put it. Friendly, thoughtful, caring, literary, and the object of near-universal admiration.
He had a long correspondence by postcard with two other Scottish physicists (Tait and William Thompson). Thomson was T, Tait was T', and some other scientist they didn't respect was T'' --because he was a second-order quantity. Apparently nerd humor has not improved with time.
January 28, 2017
Maxwell is probably as close to a hero as any man who has ever lived. Thus, from my perspective, any accurate biography of Maxwell deserves five stars merely for content. This book ably presents a short history of the great man. However, I am disappointed by the way in which the book was written. The author has chosen to follow the secularist agenda (as can be guessed since the book was recommended by the magazine – New Scientist), by relegating anything religious or spiritual to the irrelevant/private sphere. Thirty years ago, I read several biographies of Maxwell and was struck by (and encouraged by) his life that incorporated both his science and his Christianity in balance, something that I have endeavoured to do myself. Unlike many at his time, Maxwell refused to get sucked into the science vs faith controversies that appears following Darwin, and as this book pointed out was a friendly associate of Huxley. He believed that neither could operate without the other. Note also, that my assertion is very evident from a simple internet search. Getting back to this book: all aspects of Maxwell’s faith were downplayed as being irrelevant to the story. And this, I believe, misrepresents James Clerk Maxwell.
October 27, 2016
As the author admits, James Clerk Maxwell deserves to be recognized in the pantheon of Newton and Einstein. Newton unified all theories of mechanics (eg. Copernicus, Galileo, Kepler, etc); Maxwell unified all theories of electricity, magnetism and optics (eg. Faraday, Gauss, Ampere, Coulomb, etc). No small feat since it involved the novel concept of the “field” (now the basis for all fundamental theories), as first suggested by Faraday. Einstein, of course, was Einstein.
His theory (known as “Maxwell’s Equations”) predicted light was an electromagnetic wave as well as the existence of other invisible waves in empty space like xrays, radio frequencies (RF; the basis of all “wifi”) and microwaves (but don’t blame him for the “microwave oven” ;)---even Maxwell had a hard time believing they might be real. The equations also strongly presaged Relativity---the speed of light was independent of inertial frame, which was a key clue for Einstein and his Theory of Special Relativity.
In addition to the aforementioned, he founded statistical mechanics (and came eerily close to quantum mechanics, before it was accepted that “atoms” exist), theory of color vision, and the renowned Cavendish Laboratory; his Treatise “Electricity and Magnetism” stands with Newton’s “Principia” as one of the most profound books in the history of physics. Not to mention that he was a great human being: he was loved by his students, always humble and generous, loved animals, and was “a most perfect example of a Christian gentleman”. I was already familiar with his science, I read this mainly to understand his creative process better and get to know Maxwell the person. In that I was not disappointed.
As the author states: what is “more remarkable is that he is so little known to the public. Everyone has heard of Newton and Einstein but Maxwell is almost unknown outside professional circles”. Without his “Maxwell’s Equations”, modern physics and technology would not exist. He indeed “changed everything”.
His theory (known as “Maxwell’s Equations”) predicted light was an electromagnetic wave as well as the existence of other invisible waves in empty space like xrays, radio frequencies (RF; the basis of all “wifi”) and microwaves (but don’t blame him for the “microwave oven” ;)---even Maxwell had a hard time believing they might be real. The equations also strongly presaged Relativity---the speed of light was independent of inertial frame, which was a key clue for Einstein and his Theory of Special Relativity.
In addition to the aforementioned, he founded statistical mechanics (and came eerily close to quantum mechanics, before it was accepted that “atoms” exist), theory of color vision, and the renowned Cavendish Laboratory; his Treatise “Electricity and Magnetism” stands with Newton’s “Principia” as one of the most profound books in the history of physics. Not to mention that he was a great human being: he was loved by his students, always humble and generous, loved animals, and was “a most perfect example of a Christian gentleman”. I was already familiar with his science, I read this mainly to understand his creative process better and get to know Maxwell the person. In that I was not disappointed.
As the author states: what is “more remarkable is that he is so little known to the public. Everyone has heard of Newton and Einstein but Maxwell is almost unknown outside professional circles”. Without his “Maxwell’s Equations”, modern physics and technology would not exist. He indeed “changed everything”.
August 2, 2017
Nice little biography. Doesn't ever get too technical about Maxwell's work. Gives you a good overview of his contributions to science.
February 12, 2022
It's difficult to imagine people complexly when theyre alive, even harder for those dead. This book does a great job of showcasing not only Maxwell's genius but also his humanity.
October 26, 2021
The Man Who Changed Everything
Almost all, if not all, of modern physics as we know it can trace its roots to the contributions made by this one man: James Clerk Maxwell. The public's perception of "genius" is easily that of Newton or Einstein; but what about the man - who is sadly rarely understood outside of professional circles - whom Einstein, the public's genius, considers to be the genius?
Who was the man that paved the way forward for Einstein's theory of relativity? Quantum mechanics? Where would we be without the prior knowledge to have Radio? Refridgerators? Television - even colour Television? Microwaves? Photography? Thermodynamics? Understanding the Stress & Strain of properties for construction? It all started with Maxwell.
Many in the profession consider his achievements to be on par with that of Einstein and Isaac Newton. When asked if he stood on the shoulders of Newton, Einstein replied, "No, I stand on Maxwell's shoulders".
James Clerk Maxwell was himself a modest man born in Edinburgh to a minister. His keenness for questions and answers, complimented by his vision at such a young age, allowed him to reach the level of having written his first scientific peer-reviewed paper by age fourteen to do with his work on geometry and ellipses, spoken out at the Royal Society of Edinburgh by a professor of University of Edinburgh because he was too young. By sixteen, he had a few awards of recognition under his belt while attending Edinburgh Academy, and went to the University of Edinburgh, where during his studies he would experiment on the effects of magnetism and polarised light, borrowing prisms even from William Nicols himself, that would eventually lead him to discover photo-elasticity - the changes of an object through forces of pressure, leading to permanent deformation of the object.
This was not all: during his time, whilst focused on the properties of electromagnetism, he managed to explain something that no other leading scientist of his time, nor of any time for over 200 years, ever could; even while there was an ongoing open competition from Cambridge University's most prestigious prize, Adams Prize, had been around for two years - to explain the nature of Saturn's rings. His groundbreaking work was the only entrance in the entirety of the competition's event, and was commended for it.
His understanding of colours and how colours mixed together in the retina to give us the different hues was also a fascination of Maxwell that led to our first colour photograph, a tartan ribbon; his work on the kinetic theory of gases via viscocity and diffusion led to the Maxwell-Boltzmann distribution Law; on his work for electromagnetism and how they work, became Maxwell's Equations; His analytical survey for the public's perception of colours through his colour box was one of the first of any scientific statistical survey study; He discovered the nature of the forces of magnetism and introduced the idea of the electromagnetic field; he was also a pioneer of the control theory.
He was also a humble man, and an apolitical man. In his time as a teacher he tried to ensure that the students could think for themselves, critically. He also criticised the inventors and scientists of his time who would cover up their mistakes in published articles and papers, arguing that the mistakes were part of the long-process - something he would understand, as some of his papers were marked with mathematical errors, but that didn't stop him from changing the World!
Almost all, if not all, of modern physics as we know it can trace its roots to the contributions made by this one man: James Clerk Maxwell. The public's perception of "genius" is easily that of Newton or Einstein; but what about the man - who is sadly rarely understood outside of professional circles - whom Einstein, the public's genius, considers to be the genius?
Who was the man that paved the way forward for Einstein's theory of relativity? Quantum mechanics? Where would we be without the prior knowledge to have Radio? Refridgerators? Television - even colour Television? Microwaves? Photography? Thermodynamics? Understanding the Stress & Strain of properties for construction? It all started with Maxwell.
Many in the profession consider his achievements to be on par with that of Einstein and Isaac Newton. When asked if he stood on the shoulders of Newton, Einstein replied, "No, I stand on Maxwell's shoulders".
James Clerk Maxwell was himself a modest man born in Edinburgh to a minister. His keenness for questions and answers, complimented by his vision at such a young age, allowed him to reach the level of having written his first scientific peer-reviewed paper by age fourteen to do with his work on geometry and ellipses, spoken out at the Royal Society of Edinburgh by a professor of University of Edinburgh because he was too young. By sixteen, he had a few awards of recognition under his belt while attending Edinburgh Academy, and went to the University of Edinburgh, where during his studies he would experiment on the effects of magnetism and polarised light, borrowing prisms even from William Nicols himself, that would eventually lead him to discover photo-elasticity - the changes of an object through forces of pressure, leading to permanent deformation of the object.
This was not all: during his time, whilst focused on the properties of electromagnetism, he managed to explain something that no other leading scientist of his time, nor of any time for over 200 years, ever could; even while there was an ongoing open competition from Cambridge University's most prestigious prize, Adams Prize, had been around for two years - to explain the nature of Saturn's rings. His groundbreaking work was the only entrance in the entirety of the competition's event, and was commended for it.
His understanding of colours and how colours mixed together in the retina to give us the different hues was also a fascination of Maxwell that led to our first colour photograph, a tartan ribbon; his work on the kinetic theory of gases via viscocity and diffusion led to the Maxwell-Boltzmann distribution Law; on his work for electromagnetism and how they work, became Maxwell's Equations; His analytical survey for the public's perception of colours through his colour box was one of the first of any scientific statistical survey study; He discovered the nature of the forces of magnetism and introduced the idea of the electromagnetic field; he was also a pioneer of the control theory.
He was also a humble man, and an apolitical man. In his time as a teacher he tried to ensure that the students could think for themselves, critically. He also criticised the inventors and scientists of his time who would cover up their mistakes in published articles and papers, arguing that the mistakes were part of the long-process - something he would understand, as some of his papers were marked with mathematical errors, but that didn't stop him from changing the World!
April 14, 2022
A thorough gentleman.
Basil Mahon Quotes
"People who knew Maxwell have left us with more than his scientific achievements. We have a picture of a man who was the kind of friend everyone would love to have: generous, considerate, brave, genial, entertaining and entirely without vanity or pretense. The friend who knew him best described his character having "A grand simplicity": he was the same all the way through and the same to everyone.
James own reflections on his life were typically self-effacing.
"What is done by what I call myself is, I feel, done by something greater than myself in me.
I have been thinking how very gently i have been dealt with. I have never had a violent shove in all my life.
The only desire which i can have is like David to serve my own generation by the will of god, and then fall asleep."
Basil Mahon Quotes
"People who knew Maxwell have left us with more than his scientific achievements. We have a picture of a man who was the kind of friend everyone would love to have: generous, considerate, brave, genial, entertaining and entirely without vanity or pretense. The friend who knew him best described his character having "A grand simplicity": he was the same all the way through and the same to everyone.
James own reflections on his life were typically self-effacing.
"What is done by what I call myself is, I feel, done by something greater than myself in me.
I have been thinking how very gently i have been dealt with. I have never had a violent shove in all my life.
The only desire which i can have is like David to serve my own generation by the will of god, and then fall asleep."
April 23, 2025
“The influence of James Clerk Maxwell runs all through our daily lives. His electromagnetic waves bring us radio and television and provide the radar that makes safe air travel possible. Colour television works on the three-colour principle that he demonstrated. Pilots fly aircraft by control systems which derive from his work. Many of our bridges and other structures were designed using his reciprocal diagrams and photoelastic techniques.
Even more significant is his influence on the whole development of physical science. He started a revolution in the way physicists look at the world. It was he who began to think that the objects and forces that we see and feel may be merely our limited perception of an underlying reality which is inaccessible to our senses but may be described mathematically.”
Albert Einstein once remarked that, for his scientific work, he stood on the shoulders of Maxwell rather than on Isaac Newton. Indeed, the blurb on the cover of the book is a quote from Einstein concerning Maxwell: “Once scientific epoch ended and another began with James Clerk Maxwell.” In this biography, Basil Mahon introduces to the incredible character and genius of Maxwell,as well as his extremely diverse scientific interests and accomplishments. In the final chapter and end notes, there is also a helpful discussion on Maxwell’s precise influences on Einstein’s general and special theories of relativity. I will say that there is one major drawback to this book. Unlike Walter Isaacson’s excellent biography on Einstein, or Bird and Sherwin’s biography on Oppenheimer, Mahon is not simply a biographer writing about the life of a scientist. Instead, Mahon himself is a scientist writing a biography on Maxwell. In light of this, some of Mahon’s descriptions of Maxwell’s experiments and discoveries are extremely difficult to understand, and Mahon often goes into painstaking detail to describe the experiments or discoveries, even though the content is lost on readers such as myself who are not scientists by profession. Other than that, this book captures very well the life and character of Maxwell—a life that was unfortunately cut very short by sickness. Maxwell was also an extremely devout Christian. I conclude with this quote from Maxwell’s doctor about the person of Maxwell:
“I must say he is one of the best men I have ever met, and a greater merit than his scientific achievements is his being, so far as human judgement can discern, a most perfect example of a Christian Gentleman.”
Even more significant is his influence on the whole development of physical science. He started a revolution in the way physicists look at the world. It was he who began to think that the objects and forces that we see and feel may be merely our limited perception of an underlying reality which is inaccessible to our senses but may be described mathematically.”
Albert Einstein once remarked that, for his scientific work, he stood on the shoulders of Maxwell rather than on Isaac Newton. Indeed, the blurb on the cover of the book is a quote from Einstein concerning Maxwell: “Once scientific epoch ended and another began with James Clerk Maxwell.” In this biography, Basil Mahon introduces to the incredible character and genius of Maxwell,as well as his extremely diverse scientific interests and accomplishments. In the final chapter and end notes, there is also a helpful discussion on Maxwell’s precise influences on Einstein’s general and special theories of relativity. I will say that there is one major drawback to this book. Unlike Walter Isaacson’s excellent biography on Einstein, or Bird and Sherwin’s biography on Oppenheimer, Mahon is not simply a biographer writing about the life of a scientist. Instead, Mahon himself is a scientist writing a biography on Maxwell. In light of this, some of Mahon’s descriptions of Maxwell’s experiments and discoveries are extremely difficult to understand, and Mahon often goes into painstaking detail to describe the experiments or discoveries, even though the content is lost on readers such as myself who are not scientists by profession. Other than that, this book captures very well the life and character of Maxwell—a life that was unfortunately cut very short by sickness. Maxwell was also an extremely devout Christian. I conclude with this quote from Maxwell’s doctor about the person of Maxwell:
“I must say he is one of the best men I have ever met, and a greater merit than his scientific achievements is his being, so far as human judgement can discern, a most perfect example of a Christian Gentleman.”
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September 23, 2024Maxwell föddes 1831 i Edinburgh i en familj av den lägre adel (gentry) - inte vansinnig rik, men tydligt upper class. Han växte upp på landet i Glenlair, undervisades - som sig bör - hemma tills han var 10. Då kom han till Edinburgh. Han var en glad, men blyg unge.
Med 14 skrev han en uppsats om hur man man med enkla medel kan rita ellipser, men även hur man beräknar de. Hans lärare var så imponerade att de lät publicera artikeln. När han var klar med skolan med 16 började han plugga på Edinburghs universitet med tanke att bli advokat; att bli forskare eller vetenskapsman fanns inte på kartan, för det var inget yrke som gav pengar eller ens anseende, forskare var på den tiden entusiastiska amatörer som hade en inkomst från annat håll.
Men efter tre år, med 19, växlade han till Cambridge och hamnade så småningon i Trinity College. Där fick hans intellektuella nyfikenhet utlopp.
Tuffast av alla ämnen i Cambridge var matematiken (Isaac Newton, men även Charles Babbage var bärare för traditionen), men alla studenter hade även latin och grekiska. Slutproverna (för en bachelor) hade / har namnet Tripos; exempel finns på nätet. Ett omdöme om Maxwell från den tiden:
It is not possible for that man to think incorrectly on physical subjects; in his analysis, however, he is far more deficient.
1854, efter fyra år, tog han examen i Cambridge. Av studiekamraterna beskrivs han (så som tidigare) som glad, vänlig, hjälpsam och smart. Han fick ett jobb som bachelor-scholar vid universitet, men han fick tid att ägna sig åt egna studier och experiment. Ämnen som intresserade 23-åringen var bl a elektricitet och magnetism å ena sidan och å andra sidan, syn och färg.
Han började läsa Coulomb, Ampère och Faraday. De hade beskrivit fyra effekter:
1. Electric charges attract or repel one another with a force inversely proportional to the square of the distance between them: unlike charges attract, like ones repel
2. Magnetic poles attract or repel one another in a similar way but always come in pairs: every north pole is yoked to a south pole*
3. An electric current in a wire creates a circular magnetic field around the wire, its direction depending on that of the current
4. A current is induced in a loop of wire when it is moved towards or away from a magnet, or a magnet is moved towards or away from it, the direction of the current depending on that of the movement
1856 slutade han i Cambridge och fick en anställning som professor i natural philosophy i Aberdeen. Sitt första arbete där var om Planeten Saturnus, där han bevisade att ringen består av stenar i olika storlek. Sedan tog han åter upp arbetet med färgerna. Han gifte sig med Katherine May Dewar.
1861 fick han sluta i Aberdeen och gick istället till King's College i London.
Han återtog arbetet med elektromagnetiska fält. Sin vana trogen jobbade han med analogier. Han behövde förklara de fyra effekterna som han hade observerat tidigare (se ovan) och han lyckadas att hitta en modell som forklade några av effekterna. Arbetet publicerades 1861 som On Physical Lines of Force, i två delar. 1862 kom del tre och fyra, där har lyckades förklara alla effekterna: elektriska och magnetiska krafter kan existera utanför fysiska objekt, dvs som energi i utrymmet mellan dem.
Det nya och banbrytande var upptäckten att elektrisk ström kan finnas i "tomma utrymmen". Och att ändringar av det elektriska fältet fortplantar sig som vågor, vilket också gäller för ändringar i det magnetiska fältet. Upptäckten var kort och gott elektromagnetiska vågor. Det är s k tvärgående vågor: partiklarna rör sig i rät vinkel mot vågens riktning. Genom matematiska beräkningar kunde han bestämma att det är samma vågor som ljus. I Maxwells ord: Vi kan knappast undvika slutsatsen att ljuset består av tvärgående vågformer av samma medium som är orsak till elektriska och magnetiska fenomen.
Maxwells samtida hade svårt att fatta, framför allt för att all vetenskapligt tänkande förutsatte alla fysikaliska fenonem hade mekaniska orsaker; det gällde bara att hitta dem. Vågor som fortplantar sig genom det tomma rummet var en idé som var hårt att svälja. Idag anser vetenskapshistoriker att Maxwells publikation var unik i sitt sätt.
På grund av historiska anledningar fanns dt olika begrepp och mått enheter för magnetism, statisk elektricitet och elektrisk ström. Men nu hade det visat sig att de tre hänger ihop. British Association for the Advancement of Science gav Maxwell i uppdrag att skapa en standard. Han gick vidare än själva uppdraget och passade på att förslå vissa klargöranden: massa. längd och tid skulle få benämningen M, L och T, så att hastighet kan definieras med L/T, acceleration med L/T² och kraft ML/T² (eller MLT-²). Systemet används än idag.
Det var i denna period som Maxwell arbetade med vad som skulle - än idag - betraktas som hissnande i sin djärvhet, originalitet och vision: A Dynamical Theory of the Electromagnetic Field och som publicerades i sju delar. Först beskrev han elektriska och magnetiska effekter, sedan förutsade han existensen elektrisk ström och elektromagnetiska vågor, i båda fallen med hjälp av modeller och analogier. Nu försökte han förklara alla elektromagnetiska fenomen matematiskt och avstå från en modell - med andra ord: . han nöjde sig med att "matematiken stämde" och var inte beroende av att hitta en modell eller en anlogin i verkliga livet för att förklara processerna.
Han utgick ifrån att elektromagnetiska fält håller energi som motsvarar mekanisk energi, dvs elektrisk ström och magnetiska fält bär på kinetisk energi. Elektriska fält har potentiell energi, som en spänd fjäder. När elektrisk ström flödar genom en ledare händer inget, men vid isolerade material utövas en kraft som kan jämföras med en mekanisk kraft. I andra avseenden är elektromagnetiska system inte alls jämförbara med mekaniska, som när linjära elektriska krafter inducerar cirkulära magnetiska effekter (och omvänd). De flesta av värdena visade sig vara vektorer, fem stycken närmare sagt; en däremot var skalar (endast ett numeriskt värde). Maxwell kunde härleda fyra ekvationer som kopplade ihop alla värden. Även utbredning av ljus kunde förklaras med samma ekvationer from the laws of dynamics. Ekvationerna har idag benämningen "Maxwells ekvationer":
* div E = 0 (1)
* div H = 0 (2)
* curl E = -(1=c) δH=δt (3)
* curl H = (1=c) δE=δt (4)
E är den elektriska styrkan i en given punkt (och en vektor), H är den magnistiska kraften (och även den en vektor). δH=δt och δE=δt är ocksp vektorer och anger förändringshastigheten (?) för H och E. Konstanten c är förhållandet mellan de elektromagnetiska och elektrostatiska laddningsenheterna. Div är ett mått på kraftens tendens att riktas mer utåt än inåt (div större än noll), eller mer inåt än utåt (div mindre än noll). Curl, å andra sidan, mäter kraftens tendens att rotera, runt punkten och anger riktningen på axeln som den roterar runt.
Ekvationerna skrivs också i en annan notation (t ex i wikipedia). Försöker man översätta de i vardagsspråk (enligt google translate):
* Ekvation (1) säger att den elektriska kraften i ett litet område runt vår punkt har i genomsnitt ingen inåt- eller utåtgående tendens. Detta innebär att det inte finns någon elektrisk laddning.
* Ekvation (2) säger detsamma för den magnetiska kraften, vilket innebär att inga enstaka magnetiska poler finns: de kommer alltid i nord=sydlig par i alla fall.
* De två första ekvationerna antyder också de välkända lagarna för statiska fält: att krafterna mellan elektriska laddningar och mellan magnetiska poler varierar omvänt med kvadraten på avståndet som skiljer dem åt.
* Ekvation (3) säger att när den magnetiska kraften ändras, skapar den en cirkulär elektrisk kraft runt sig själv. Minustecknet betyder att känslan av den elektriska kraften är moturs sett i riktningen för den magnetiska kraftens förändringshastighet.
* Ekvation (4) säger att när den elektriska kraften ändras, skapar den en cirkulär magnetisk kraft runt sig själv. Avkänningen av den magnetiska kraften är medurs när den ses i riktningen för förändringshastigheten för den elektriska kraften.
* I ekvationerna (3) och (4) förbinder konstanten c rymdvariationen (curl) för den magnetiska kraften till tidsvariationen (δ=δt) för den elektriska kraften, och vice versa. Den har dimensionerna av en hastighet och, som Maxwell riktigt drog slutsatsen, är den hastigheten med vilken elektromagnetiska vågor, inklusive ljus, färdas.
Varje förändring i antingen de elektriska eller magnetiska fälten sänder en kombinerad tvärgående elektromagnetisk våg genom rymden med en hastighet som är lika med förhållandet mellan de elektromagnetiska och elektrostatiska laddningsenheterna.
Maxwell var den som - efter flera experimentella bevis - la fram det matematiska beviset. Och allt byggde på en briljant tanke: tanken att elektriska strömmar existerar i tomma rummet och idén om displacement current.
Samtiden hade svårt att förstå Maxwells teori. Först när Hertz 20 år senare genom experiment påvisade elektromagnetiska vågor, fattade folk.
1865 gav Maxwell upp sin post i Kings College och drog sig tillbaka till Glenlair för att av med bördan av att undervisa. Han vill fortsätta experimentera med färgseende, med sin teori om gaser och med elektromagnetiska fält. Han var 35 år, hans fru Katherine var 42, de hande inga barn och skulle inte heller få några. Han beskrevs som en trevlig man, med humor och som var kvick and skämtsam. Han stannade i sex år i Glenlair, publicerade massor under tiden, bl a en bok, The Theory of Heat 1871 och förberedde Treatise on Electricity and Magnetism. Men han hade tid (och pengar) att med sin fru göra "the grand tour", dvs en längre resa till Italien.
1866 kom On the Dynamical Theory of Gases, där han rättade några fel i pappret från 1860. Sedan ville han genom experiment fastställa hastigheten av elektromagnetiska vågor.
I The Theory of Heat finns hans berömda "Maxwells demon", som han som djup religiös person aldrig kallade så. Med hjälp av tankeexperimentet försökte han utmana termodynamikens andra huvudsats: En liten varelse bevakar förbindelsen mellan två behållare fyllda med gas. Varelsen öppnar dörren åt det ena hållet när en molekyl i den ena behållaren, med högre värme, närmar sig och släpper in den till den andra behållaren. Och vice versa. På så sätt borde så småningom den ena behållaren bli varmare och de andra kallare. Entropin minskar, och bättre än så, en evighetsmaskin skulle kunna byggas med hjälp av principen. Varför kan det inte stämma? Maxwell förklarade så här: För det första handlar andra huvudsatsen om "mängden av molekylerna", inte enstaka; med andra ord: det handlar om en statistisk lag. För det andra behöver varelsen (demonen) ha oändligt med information om enstaka molekylernas position och hastighet och detta hela tiden. 50 år senare bevisades att dessa kontinuerliga mätningar ökar entropin. Diskussion om Maxwells demon sparkade igång skapandet av informationsteorin.
Ett arbete handlar om regulatorer (On Governors) och blev senare startpunkten för modern kontrollteori. Ett annat On Hills and Dales gav upphov till topologi och meteorologi.
1873 kom Treatise on Electricity and Magnetism, huvudverket. I boken börjande Maxwell att använda en annan notation för vektorerna - kvaternion, som består av en skalar del (ett nummer eller värde) och tre delar för vektordelar (för de tre riktningarna x, y och z) - kvaternioner är svåra att förstå och så småningom blev de ersatta att vektoranalys. Samtidigt introducerade Maxwell curl, divergence och gradient (egentligen använde han convergense som blev ersatt av sin motsats). Alla tre används fortfarande idag (som curl, div och grad). Curl och div beskriver two kinds of space variation of vectors, medan grad står för the direction and rate of change of a scalar quantity in space.
1871 blev han erbjuden uppgiften att starta ett nytt forskningslabb i Cambridge - Cavendish laboratoriet; efter lite tveksamhet tog han jobbet. Hans invigningstal som professor handlade om den yttersta betydelsen som experiment har och att det inte alls var "färdigforskat". 25 år senare skulle en efterträdare till honom hitta elektronen, i Cavendish labb (JJ Thomson).
I denna veva fick han i uppdrag att publicera Henry Cavendishs arbeten om elektricitet, som var några decennier gamla - inte något som han såg framemot, men gjorde i alla fall. De publicerades 1879, bara veckor innan Maxwell själv avled.
Allt arbete med labbet och med publiaktionen av Cavendishs texter och mång andra uppgifter som ingick i jobbet gjorde att hans eget forskande blev lidande. Men han fortsatte med Treatise och försökta bearbeta boken. Han förutsåg att elektromagnetiska vågor utövar ett strålningstryck på ytan som de träffar, t ex solljudet på jorden. Värdet är så litet, att det är svårt att mäta, men 1900 lyckades Lebedev. Den kraften ser bland annat till att stjärnor inte kollapsar under sin egen gravitation.
Så småningom blev han klar med Cavendishs papper. Han tillbringade fyra månader per år i Glenlain, trivdes med arbetet, labbet var klart och fungerade över förväntan, och han själv hoppades nu kunna återuppta forskningen lite mera seriöst. Men då fick han cancer. James Clerk Maxwell dog 1879.
He started a revolution in the way physicists look at the world. It was he who began to think that the objects and forces that we see and feel may be merely our limited perception of an underlying reality which is inaccessible to our senses but may be described mathematically.
Med 14 skrev han en uppsats om hur man man med enkla medel kan rita ellipser, men även hur man beräknar de. Hans lärare var så imponerade att de lät publicera artikeln. När han var klar med skolan med 16 började han plugga på Edinburghs universitet med tanke att bli advokat; att bli forskare eller vetenskapsman fanns inte på kartan, för det var inget yrke som gav pengar eller ens anseende, forskare var på den tiden entusiastiska amatörer som hade en inkomst från annat håll.
Men efter tre år, med 19, växlade han till Cambridge och hamnade så småningon i Trinity College. Där fick hans intellektuella nyfikenhet utlopp.
Tuffast av alla ämnen i Cambridge var matematiken (Isaac Newton, men även Charles Babbage var bärare för traditionen), men alla studenter hade även latin och grekiska. Slutproverna (för en bachelor) hade / har namnet Tripos; exempel finns på nätet. Ett omdöme om Maxwell från den tiden:
It is not possible for that man to think incorrectly on physical subjects; in his analysis, however, he is far more deficient.
1854, efter fyra år, tog han examen i Cambridge. Av studiekamraterna beskrivs han (så som tidigare) som glad, vänlig, hjälpsam och smart. Han fick ett jobb som bachelor-scholar vid universitet, men han fick tid att ägna sig åt egna studier och experiment. Ämnen som intresserade 23-åringen var bl a elektricitet och magnetism å ena sidan och å andra sidan, syn och färg.
Han började läsa Coulomb, Ampère och Faraday. De hade beskrivit fyra effekter:
1. Electric charges attract or repel one another with a force inversely proportional to the square of the distance between them: unlike charges attract, like ones repel
2. Magnetic poles attract or repel one another in a similar way but always come in pairs: every north pole is yoked to a south pole*
3. An electric current in a wire creates a circular magnetic field around the wire, its direction depending on that of the current
4. A current is induced in a loop of wire when it is moved towards or away from a magnet, or a magnet is moved towards or away from it, the direction of the current depending on that of the movement
1856 slutade han i Cambridge och fick en anställning som professor i natural philosophy i Aberdeen. Sitt första arbete där var om Planeten Saturnus, där han bevisade att ringen består av stenar i olika storlek. Sedan tog han åter upp arbetet med färgerna. Han gifte sig med Katherine May Dewar.
1861 fick han sluta i Aberdeen och gick istället till King's College i London.
Han återtog arbetet med elektromagnetiska fält. Sin vana trogen jobbade han med analogier. Han behövde förklara de fyra effekterna som han hade observerat tidigare (se ovan) och han lyckadas att hitta en modell som forklade några av effekterna. Arbetet publicerades 1861 som On Physical Lines of Force, i två delar. 1862 kom del tre och fyra, där har lyckades förklara alla effekterna: elektriska och magnetiska krafter kan existera utanför fysiska objekt, dvs som energi i utrymmet mellan dem.
Det nya och banbrytande var upptäckten att elektrisk ström kan finnas i "tomma utrymmen". Och att ändringar av det elektriska fältet fortplantar sig som vågor, vilket också gäller för ändringar i det magnetiska fältet. Upptäckten var kort och gott elektromagnetiska vågor. Det är s k tvärgående vågor: partiklarna rör sig i rät vinkel mot vågens riktning. Genom matematiska beräkningar kunde han bestämma att det är samma vågor som ljus. I Maxwells ord: Vi kan knappast undvika slutsatsen att ljuset består av tvärgående vågformer av samma medium som är orsak till elektriska och magnetiska fenomen.
Maxwells samtida hade svårt att fatta, framför allt för att all vetenskapligt tänkande förutsatte alla fysikaliska fenonem hade mekaniska orsaker; det gällde bara att hitta dem. Vågor som fortplantar sig genom det tomma rummet var en idé som var hårt att svälja. Idag anser vetenskapshistoriker att Maxwells publikation var unik i sitt sätt.
På grund av historiska anledningar fanns dt olika begrepp och mått enheter för magnetism, statisk elektricitet och elektrisk ström. Men nu hade det visat sig att de tre hänger ihop. British Association for the Advancement of Science gav Maxwell i uppdrag att skapa en standard. Han gick vidare än själva uppdraget och passade på att förslå vissa klargöranden: massa. längd och tid skulle få benämningen M, L och T, så att hastighet kan definieras med L/T, acceleration med L/T² och kraft ML/T² (eller MLT-²). Systemet används än idag.
Det var i denna period som Maxwell arbetade med vad som skulle - än idag - betraktas som hissnande i sin djärvhet, originalitet och vision: A Dynamical Theory of the Electromagnetic Field och som publicerades i sju delar. Först beskrev han elektriska och magnetiska effekter, sedan förutsade han existensen elektrisk ström och elektromagnetiska vågor, i båda fallen med hjälp av modeller och analogier. Nu försökte han förklara alla elektromagnetiska fenomen matematiskt och avstå från en modell - med andra ord: . han nöjde sig med att "matematiken stämde" och var inte beroende av att hitta en modell eller en anlogin i verkliga livet för att förklara processerna.
Han utgick ifrån att elektromagnetiska fält håller energi som motsvarar mekanisk energi, dvs elektrisk ström och magnetiska fält bär på kinetisk energi. Elektriska fält har potentiell energi, som en spänd fjäder. När elektrisk ström flödar genom en ledare händer inget, men vid isolerade material utövas en kraft som kan jämföras med en mekanisk kraft. I andra avseenden är elektromagnetiska system inte alls jämförbara med mekaniska, som när linjära elektriska krafter inducerar cirkulära magnetiska effekter (och omvänd). De flesta av värdena visade sig vara vektorer, fem stycken närmare sagt; en däremot var skalar (endast ett numeriskt värde). Maxwell kunde härleda fyra ekvationer som kopplade ihop alla värden. Även utbredning av ljus kunde förklaras med samma ekvationer from the laws of dynamics. Ekvationerna har idag benämningen "Maxwells ekvationer":
* div E = 0 (1)
* div H = 0 (2)
* curl E = -(1=c) δH=δt (3)
* curl H = (1=c) δE=δt (4)
E är den elektriska styrkan i en given punkt (och en vektor), H är den magnistiska kraften (och även den en vektor). δH=δt och δE=δt är ocksp vektorer och anger förändringshastigheten (?) för H och E. Konstanten c är förhållandet mellan de elektromagnetiska och elektrostatiska laddningsenheterna. Div är ett mått på kraftens tendens att riktas mer utåt än inåt (div större än noll), eller mer inåt än utåt (div mindre än noll). Curl, å andra sidan, mäter kraftens tendens att rotera, runt punkten och anger riktningen på axeln som den roterar runt.
Ekvationerna skrivs också i en annan notation (t ex i wikipedia). Försöker man översätta de i vardagsspråk (enligt google translate):
* Ekvation (1) säger att den elektriska kraften i ett litet område runt vår punkt har i genomsnitt ingen inåt- eller utåtgående tendens. Detta innebär att det inte finns någon elektrisk laddning.
* Ekvation (2) säger detsamma för den magnetiska kraften, vilket innebär att inga enstaka magnetiska poler finns: de kommer alltid i nord=sydlig par i alla fall.
* De två första ekvationerna antyder också de välkända lagarna för statiska fält: att krafterna mellan elektriska laddningar och mellan magnetiska poler varierar omvänt med kvadraten på avståndet som skiljer dem åt.
* Ekvation (3) säger att när den magnetiska kraften ändras, skapar den en cirkulär elektrisk kraft runt sig själv. Minustecknet betyder att känslan av den elektriska kraften är moturs sett i riktningen för den magnetiska kraftens förändringshastighet.
* Ekvation (4) säger att när den elektriska kraften ändras, skapar den en cirkulär magnetisk kraft runt sig själv. Avkänningen av den magnetiska kraften är medurs när den ses i riktningen för förändringshastigheten för den elektriska kraften.
* I ekvationerna (3) och (4) förbinder konstanten c rymdvariationen (curl) för den magnetiska kraften till tidsvariationen (δ=δt) för den elektriska kraften, och vice versa. Den har dimensionerna av en hastighet och, som Maxwell riktigt drog slutsatsen, är den hastigheten med vilken elektromagnetiska vågor, inklusive ljus, färdas.
Varje förändring i antingen de elektriska eller magnetiska fälten sänder en kombinerad tvärgående elektromagnetisk våg genom rymden med en hastighet som är lika med förhållandet mellan de elektromagnetiska och elektrostatiska laddningsenheterna.
Maxwell var den som - efter flera experimentella bevis - la fram det matematiska beviset. Och allt byggde på en briljant tanke: tanken att elektriska strömmar existerar i tomma rummet och idén om displacement current.
Samtiden hade svårt att förstå Maxwells teori. Först när Hertz 20 år senare genom experiment påvisade elektromagnetiska vågor, fattade folk.
1865 gav Maxwell upp sin post i Kings College och drog sig tillbaka till Glenlair för att av med bördan av att undervisa. Han vill fortsätta experimentera med färgseende, med sin teori om gaser och med elektromagnetiska fält. Han var 35 år, hans fru Katherine var 42, de hande inga barn och skulle inte heller få några. Han beskrevs som en trevlig man, med humor och som var kvick and skämtsam. Han stannade i sex år i Glenlair, publicerade massor under tiden, bl a en bok, The Theory of Heat 1871 och förberedde Treatise on Electricity and Magnetism. Men han hade tid (och pengar) att med sin fru göra "the grand tour", dvs en längre resa till Italien.
1866 kom On the Dynamical Theory of Gases, där han rättade några fel i pappret från 1860. Sedan ville han genom experiment fastställa hastigheten av elektromagnetiska vågor.
I The Theory of Heat finns hans berömda "Maxwells demon", som han som djup religiös person aldrig kallade så. Med hjälp av tankeexperimentet försökte han utmana termodynamikens andra huvudsats: En liten varelse bevakar förbindelsen mellan två behållare fyllda med gas. Varelsen öppnar dörren åt det ena hållet när en molekyl i den ena behållaren, med högre värme, närmar sig och släpper in den till den andra behållaren. Och vice versa. På så sätt borde så småningom den ena behållaren bli varmare och de andra kallare. Entropin minskar, och bättre än så, en evighetsmaskin skulle kunna byggas med hjälp av principen. Varför kan det inte stämma? Maxwell förklarade så här: För det första handlar andra huvudsatsen om "mängden av molekylerna", inte enstaka; med andra ord: det handlar om en statistisk lag. För det andra behöver varelsen (demonen) ha oändligt med information om enstaka molekylernas position och hastighet och detta hela tiden. 50 år senare bevisades att dessa kontinuerliga mätningar ökar entropin. Diskussion om Maxwells demon sparkade igång skapandet av informationsteorin.
Ett arbete handlar om regulatorer (On Governors) och blev senare startpunkten för modern kontrollteori. Ett annat On Hills and Dales gav upphov till topologi och meteorologi.
1873 kom Treatise on Electricity and Magnetism, huvudverket. I boken börjande Maxwell att använda en annan notation för vektorerna - kvaternion, som består av en skalar del (ett nummer eller värde) och tre delar för vektordelar (för de tre riktningarna x, y och z) - kvaternioner är svåra att förstå och så småningom blev de ersatta att vektoranalys. Samtidigt introducerade Maxwell curl, divergence och gradient (egentligen använde han convergense som blev ersatt av sin motsats). Alla tre används fortfarande idag (som curl, div och grad). Curl och div beskriver two kinds of space variation of vectors, medan grad står för the direction and rate of change of a scalar quantity in space.
1871 blev han erbjuden uppgiften att starta ett nytt forskningslabb i Cambridge - Cavendish laboratoriet; efter lite tveksamhet tog han jobbet. Hans invigningstal som professor handlade om den yttersta betydelsen som experiment har och att det inte alls var "färdigforskat". 25 år senare skulle en efterträdare till honom hitta elektronen, i Cavendish labb (JJ Thomson).
I denna veva fick han i uppdrag att publicera Henry Cavendishs arbeten om elektricitet, som var några decennier gamla - inte något som han såg framemot, men gjorde i alla fall. De publicerades 1879, bara veckor innan Maxwell själv avled.
Allt arbete med labbet och med publiaktionen av Cavendishs texter och mång andra uppgifter som ingick i jobbet gjorde att hans eget forskande blev lidande. Men han fortsatte med Treatise och försökta bearbeta boken. Han förutsåg att elektromagnetiska vågor utövar ett strålningstryck på ytan som de träffar, t ex solljudet på jorden. Värdet är så litet, att det är svårt att mäta, men 1900 lyckades Lebedev. Den kraften ser bland annat till att stjärnor inte kollapsar under sin egen gravitation.
Så småningom blev han klar med Cavendishs papper. Han tillbringade fyra månader per år i Glenlain, trivdes med arbetet, labbet var klart och fungerade över förväntan, och han själv hoppades nu kunna återuppta forskningen lite mera seriöst. Men då fick han cancer. James Clerk Maxwell dog 1879.
He started a revolution in the way physicists look at the world. It was he who began to think that the objects and forces that we see and feel may be merely our limited perception of an underlying reality which is inaccessible to our senses but may be described mathematically.
August 2, 2019
The normally irascible Isaac Newton remarked in 1676 …….. If I have seen further it is by standing on the sholders [sic] of Giants. In turn, Einstein, when told that he had done great things because he stood on Newton's shoulders; Einstein replied: No I don't. I stand on the shoulders of Maxwell.
The influence of James Clerk Maxwell runs all through our daily lives. His electromagnetic waves made possible ALL forms of wireless communication. Colour TV and mobile phone screens work on the three-colour principle that he demonstrated. Pilots and astronauts fly their craft by control systems which derive from his work. Bridges and other structures were designed using his reciprocal diagrams and photoelastic techniques.
Maxwell started a revolution in the way physicists look at the world. He introduced statistical methods in physics. His droll molecule sized creature, Maxwell’s Demon, was the first example of the thought experiment so frequently used by Einstein and memorably by Schrodinger with his famously lamentable cat. At Cambridge he set up the Cavendish Lab where the electron and the atomic structure were discovered by Thomson and Rutherford later on.
His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as the 19th-century scientist having the greatest influence on 20th-century physics. His contributions to the science are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein. In the millennium poll—a survey of the 100 most prominent physicists—Maxwell was voted the third greatest physicist of all time, behind only Newton and Einstein. On the centenary of Maxwell's birthday, Einstein described Maxwell's work as the most profound and the most fruitful that physics has experienced since the time of Newton.
Maxwell's A Treatise on Electricity and Magnetism: Vol. 2 is probably, after Newton'sThe Principia: Mathematical Principles of Natural Philosophy, the most renowned book in the history of physics. It is said that if you trace every line of modern physical research to its starting point you come back to Maxwell.
Maxwell achieved all this in a short span of life – he died at the age of 48.
So why is he not as well-known as Newton and Einstein or even Schrodinger, Planck or Bohr? Apparently he was painfully modest (laid back in today's argot) and never strove to promote his work; nor was there anyone who did it for him. Most importantly many of his ideas were way ahead of their time. Physicists recognized his work later, once experimental proof became available.
An engrossing book indeed.
The influence of James Clerk Maxwell runs all through our daily lives. His electromagnetic waves made possible ALL forms of wireless communication. Colour TV and mobile phone screens work on the three-colour principle that he demonstrated. Pilots and astronauts fly their craft by control systems which derive from his work. Bridges and other structures were designed using his reciprocal diagrams and photoelastic techniques.
Maxwell started a revolution in the way physicists look at the world. He introduced statistical methods in physics. His droll molecule sized creature, Maxwell’s Demon, was the first example of the thought experiment so frequently used by Einstein and memorably by Schrodinger with his famously lamentable cat. At Cambridge he set up the Cavendish Lab where the electron and the atomic structure were discovered by Thomson and Rutherford later on.
His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as the 19th-century scientist having the greatest influence on 20th-century physics. His contributions to the science are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein. In the millennium poll—a survey of the 100 most prominent physicists—Maxwell was voted the third greatest physicist of all time, behind only Newton and Einstein. On the centenary of Maxwell's birthday, Einstein described Maxwell's work as the most profound and the most fruitful that physics has experienced since the time of Newton.
Maxwell's A Treatise on Electricity and Magnetism: Vol. 2 is probably, after Newton'sThe Principia: Mathematical Principles of Natural Philosophy, the most renowned book in the history of physics. It is said that if you trace every line of modern physical research to its starting point you come back to Maxwell.
Maxwell achieved all this in a short span of life – he died at the age of 48.
So why is he not as well-known as Newton and Einstein or even Schrodinger, Planck or Bohr? Apparently he was painfully modest (laid back in today's argot) and never strove to promote his work; nor was there anyone who did it for him. Most importantly many of his ideas were way ahead of their time. Physicists recognized his work later, once experimental proof became available.
An engrossing book indeed.
June 13, 2014
El libro relata no sólo la vida de Maxwell sino también explica someramente los vericuetos que tuvo que superar este gran científico en cada uno de sus impresionantes logros. Hasta ahora las 4 ecuaciones del electromagnetismo eran para mi algo como magia negra, me resignaba a pensar que Maxwell era un iluminado y que, como a Moisés, un día Dios le dictó la forma final de las ecuaciones que llevan su nombre. Me sorprendió el ingenioso modelo mecánico que inspiró y llevó al formalismo que se usa hoy en día, por fin comprendí la razón de ser del término “corriente de desplazamiento”.
Adicionalmente, el libro muestra amenamente la parte humana del científico, su afición a la poesía, su religiosidad, su sencillez, todo esto sólo incrementó mi admiración hacia James Clerk Maxwell, que además de un gran físico fue sin duda una gran persona. Hubiera deseado que el libro contuviera en apéndices información un poco más técnica para aclarar mejor los experimentos y logros teóricos que se mencionan en el libro.
Adicionalmente, el libro muestra amenamente la parte humana del científico, su afición a la poesía, su religiosidad, su sencillez, todo esto sólo incrementó mi admiración hacia James Clerk Maxwell, que además de un gran físico fue sin duda una gran persona. Hubiera deseado que el libro contuviera en apéndices información un poco más técnica para aclarar mejor los experimentos y logros teóricos que se mencionan en el libro.
July 22, 2021
The author puts forward the notion that James Clerk Maxwell is perhaps the most underappreciated figure in the history of Science and he goes on to make a pretty good case. I have had a layman's interest in modern (17th Century forward) science all my life. The name James Clerk Maxwell has popped up in many other books, but often as only the author of Maxwell's Equations which were never explained, but only described as the basic equations of electro-magnetism and so the foundation of modern physics. This biography is an excellent introduction to a man definitely underappreciated. There may be other, better explanations of the work of Maxwell, but if you are looking for a readable introduction to the man, I highly recommend this one. Warning: There is definitely a possibility that this volume with inspire you to browse through "A Treatise on Electricity and Magnetism", which according to Mahon is also a pretty readable book.
June 3, 2011
I mean, read this book, whoever you are, what ever you do. The man, the (victorian) times, the things that were happening, the intellectual challenges and the beauty of the then found solutions or at least the attempts to find them, and as it all came together to be one of most interesting episodes in human history, portrayed in the life of James Clerk Maxwell made this, one of the most pleasing books to ever have crossed my eyes. The best part is to find a most generous, interested and interesting personality behind it all. I mean, read this book... [I didn't tell you that Maxwell is a longtime personal hero of mine. But I would do the same review had the book been about William Thomson or Oliver Heaviside. Not my fault that Maxwell was The Man and the book is about him (=]
April 13, 2024
Half the formulae you're taught in undergrad chemistry come from this man; it's true that they are not properly credited and that we generally under-credit Maxwell in comparison to the other cultural paragons of science (Einstein etc). But this book reads somewhat slowly, because of the filler: Maxwell's poems, holidays, stories about his friends and his jokes (none of which are particularly good) broke the flow for me. Some may find this a more human account of a larger than life figure, I just found it boring. For good scientific biography see Jimmy Soni's book about Claude Shannon.
February 20, 2008
I got this book for Christmas and loved it. It's amazing to read about how much of our current understanding of science we owe to this incredible man.
October 15, 2018
I get a kick out of learning how human knowledge evolves. Particularly scientific knowledge. This biography by Basil Mahon gave me the level of biographical detail that I like for a person that made contributions is so many areas. It was not overloaded with math, nor with detail about Maxwell’s personal life, making for a fairly short biography presenting a compact description of the his many accomplishments. There is little math notation in the book but his wave equations were presented for the reader to see their simplicity and elegance. There is much discussion of the interrelationships of other scientist’s findings with Maxwell’s thinking and Maxwell’s profound influence on the scientific advances surging ahead by leaps and bounds. Maxwell built many mechanical models to demonstrate his concepts. His leadership of the Cavandish laboratory at Cambridge resulted in its resurgence and opened the door for the great Earnest Rutherford to follow in that installation in the tradition of experimentation using models. Maxwell also applied mathematical techniques. Perhaps the best known is his works on electromagnetic waves and how his equations defined basic properties of light—opening the door for Einstein to define the relation of mass to energy with the simple equation, e=mc2.
A theme that runs through the book is how little recognition Maxwell received for his work, in comparison with Einstein, Newton, and Darwin. Maxwell’s contributions were of the quality of these Olympian scientists. He wrote papers and books of a scientific nature but was a humble person who did not seek publicity. He was busy with many things such as managing his large Scottish estate, and contributing to the religious and educational life of his community. His energetic life came to an early end at age forty eight because of stomach cancer. By all accounts he lead a well-ordered, busy life that Mahon portrays in a young-adult, always-admiring style that I felt lacked the gravitas of a major biography. For example: he refers to Maxwell as “James.” Also the book would have benefited by a good copy edit to get rid of numerous small errors. On the other hand the Notes at the end of the book were an added benefit for the serious science reader. I rated it four stars for presenting what I was looking for: clear definition of Maxwell's powerful impact on the evolution of science.
A theme that runs through the book is how little recognition Maxwell received for his work, in comparison with Einstein, Newton, and Darwin. Maxwell’s contributions were of the quality of these Olympian scientists. He wrote papers and books of a scientific nature but was a humble person who did not seek publicity. He was busy with many things such as managing his large Scottish estate, and contributing to the religious and educational life of his community. His energetic life came to an early end at age forty eight because of stomach cancer. By all accounts he lead a well-ordered, busy life that Mahon portrays in a young-adult, always-admiring style that I felt lacked the gravitas of a major biography. For example: he refers to Maxwell as “James.” Also the book would have benefited by a good copy edit to get rid of numerous small errors. On the other hand the Notes at the end of the book were an added benefit for the serious science reader. I rated it four stars for presenting what I was looking for: clear definition of Maxwell's powerful impact on the evolution of science.
December 11, 2022
This is an excellent view into the life of James Clerk Maxwell. It begins with his childhood and his fascination with the why of everything. It is easy to see how such a curious mind blossomed into the unimaginable intelligence he was to become.
The chronological journey is effectively arranged and conveyed. Details begin with his education in various schools. We learn of opportunities along the way, largely due to Maxwell 's insatiable curiosity and phenomenal efforts in discovery/ experimentation/ thinking.
Second, we learn of Maxwell's purity in intent. He was just consumed with improving/contributing to the world.
Some of Maxwell's deficiencies were also described. He was at best an average teacher. His lectures were not effectively focused and he would be drawn off to tangents--very interesting diversions but not usually relevant to the class being taught. Furthermore his mathematical calculations often contained errors. Since these mistakes were not uncommon, one wonders how much more and more quickly he could have reached his conclusions without the numerical mistakes.
Next, we learn of his compatriots in the scientific community. Maxwell worked extraordinary well with almost everyone he ever met. The one disgruntled relationship was near the end of Maxwell's life, and Maxwell would almost certainly have smoothed that confusion/misunderstanding if he had lived long enough to contact the disgruntled party.
Additionally, Mahon details lightly the relation between James and his wife. It appears there is confusion about the role/significance Maxwell's wife played in his life. Without a doubt, his wife was someone Maxwell cared very deeply for, and Maxwell exhibited this love actively. Mahon suggests the conflicting reports regarding Maxwell's wife could be traced to some sources being more critical in judging than should be practically applied.
Finally, Maxwell's death briefly concludes the book. It is a very concise wrap-up of a life actively lived and generously expended.
This is a good, shorter (186 pages) summary of his life. The text flows smoothly. The notes are interesting but nothing is compelling or detailed enough to merit reading to find some fascinating detail not covered in the main text. Ultimately a great, relatively detailed overview of the scientific life of James Clerk Maxwell.
The chronological journey is effectively arranged and conveyed. Details begin with his education in various schools. We learn of opportunities along the way, largely due to Maxwell 's insatiable curiosity and phenomenal efforts in discovery/ experimentation/ thinking.
Second, we learn of Maxwell's purity in intent. He was just consumed with improving/contributing to the world.
Some of Maxwell's deficiencies were also described. He was at best an average teacher. His lectures were not effectively focused and he would be drawn off to tangents--very interesting diversions but not usually relevant to the class being taught. Furthermore his mathematical calculations often contained errors. Since these mistakes were not uncommon, one wonders how much more and more quickly he could have reached his conclusions without the numerical mistakes.
Next, we learn of his compatriots in the scientific community. Maxwell worked extraordinary well with almost everyone he ever met. The one disgruntled relationship was near the end of Maxwell's life, and Maxwell would almost certainly have smoothed that confusion/misunderstanding if he had lived long enough to contact the disgruntled party.
Additionally, Mahon details lightly the relation between James and his wife. It appears there is confusion about the role/significance Maxwell's wife played in his life. Without a doubt, his wife was someone Maxwell cared very deeply for, and Maxwell exhibited this love actively. Mahon suggests the conflicting reports regarding Maxwell's wife could be traced to some sources being more critical in judging than should be practically applied.
Finally, Maxwell's death briefly concludes the book. It is a very concise wrap-up of a life actively lived and generously expended.
This is a good, shorter (186 pages) summary of his life. The text flows smoothly. The notes are interesting but nothing is compelling or detailed enough to merit reading to find some fascinating detail not covered in the main text. Ultimately a great, relatively detailed overview of the scientific life of James Clerk Maxwell.
November 1, 2020
I had heard of James Clerk Maxwell many times -- in my high school physics courses, college and graduate studies courses, and as a professor -- but I never truly understood his impact or relative place in science. Mahon's The Man Who Changes Everything: The Life of James Clerk Maxwell provides a holistic view of Maxwell in natural philosophy (i.e., physical science), his relationship with contemporaries, and his personal life journey.
Maxwell was simply an amazing mind and human - a once-in-a-generation individual that so completely and thoroughly revolutionized a particular area of science that they cannot be ignored. What makes Maxwell even more remarkable is that he touched so many areas of physics and chemistry with his fundamental theories and mathematical functions, providing the bedrock for the advancement of physics for those that followed him (e.g., Einstein, Hertz, Marconi, Plank). Ironically, most of society outside the domains of physics and chemistry know nothing about Maxwell.
This book is well-written and edited and, hence, can be quickly read. Brief notes are provided at the end of the book for each chapter, though I would have appreciated a bit more detail in these notes to better flesh out the topic being discussed. Also included is an excellent bibliography and index.
Maxwell was simply an amazing mind and human - a once-in-a-generation individual that so completely and thoroughly revolutionized a particular area of science that they cannot be ignored. What makes Maxwell even more remarkable is that he touched so many areas of physics and chemistry with his fundamental theories and mathematical functions, providing the bedrock for the advancement of physics for those that followed him (e.g., Einstein, Hertz, Marconi, Plank). Ironically, most of society outside the domains of physics and chemistry know nothing about Maxwell.
This book is well-written and edited and, hence, can be quickly read. Brief notes are provided at the end of the book for each chapter, though I would have appreciated a bit more detail in these notes to better flesh out the topic being discussed. Also included is an excellent bibliography and index.
December 17, 2022
Very worth reading, especially if, as I did, you have never heard of James Clerk Maxwell, "Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the 'second great unification in physics' where the first one had been realised by Isaac Newton." (Wikipedia) I stumbled upon his contributions to science here: https://youtu.be/UlbCx-s3Jwg Thank you, thank you, Bruce Fummey!
In addition to being a genius celebrated by Einstein, Clerk Maxwell was a funny, kind, and decent man, which I suspect, since he was more interested in discovery and collegiality than in fame, is why he isn't better known.
Highly recommended, although the scientific stuff doesn't seem as readily accessible to me as it was claimed. But as I mentioned, I am not a math/science person, so your results may differ.
In addition to being a genius celebrated by Einstein, Clerk Maxwell was a funny, kind, and decent man, which I suspect, since he was more interested in discovery and collegiality than in fame, is why he isn't better known.
Highly recommended, although the scientific stuff doesn't seem as readily accessible to me as it was claimed. But as I mentioned, I am not a math/science person, so your results may differ.
May 29, 2022
"It is sometimes said, with no more than a slight overstatement, that if you trace every line of modern physical research to its starting point you come back to Maxwell".
I think the biggest issue with the book is the fact that Maxwell never had the reverence that Einstein or Feynman had- he was too early. This meant that a large part of who he was(and not what he accomplished) is still unclear.
This book does a brilliant job at telling us how profoundly Maxwell impacted science, but you never really understood who he was as a person. Most of the pre-Einstein physicist make an appearance, and you are truly left astounded by how many different fields Maxwell had pathbreaking impacts in. But that basically is all this book accomplished.
Read this book to pay tribute to the most influential physicist after Newton and Einstein. If you want to know how physics evolved in the 1800s or how Maxwell was as a person, I'd recommend looking elsewhere.
I think the biggest issue with the book is the fact that Maxwell never had the reverence that Einstein or Feynman had- he was too early. This meant that a large part of who he was(and not what he accomplished) is still unclear.
This book does a brilliant job at telling us how profoundly Maxwell impacted science, but you never really understood who he was as a person. Most of the pre-Einstein physicist make an appearance, and you are truly left astounded by how many different fields Maxwell had pathbreaking impacts in. But that basically is all this book accomplished.
Read this book to pay tribute to the most influential physicist after Newton and Einstein. If you want to know how physics evolved in the 1800s or how Maxwell was as a person, I'd recommend looking elsewhere.
February 21, 2025
This was a curious reading experience--between the typeface and the style itself it felt like something that might have been written a hundred years ago, though it seems to have been published in 2004. It's a very straightforward and brief biography of an enormously consequential person whom the author persuasively argues hasn't recieved his fair share of appreciation and fame. Honestly the nature of many of his discoveries were a little impenetrable to me. This was a fascinating time for science, really a bridge between the "natural philosophy" of Newton's time and the advanced theoretical physcis of Einstein. And I guess Maxwell's generation was probably the last where a single scholar could make important contributions is so many widely different fields.
March 4, 2025
Maxwell is fascinating and underappreciated -- not only a model of scientific genius but of genius in general. Maxwell had not only scientific curiosity but also philosophical care for the way discovery is approached, and this fused with a poetic and passionate spirit to produce a truly singular mind. He seems to have revolutionized everything he touched, and yet the layman will rarely include him on their list of great minds of the past. Reading about his life has motivated me to read some of his work directly, but also just to get out there and start applying myself more. I think I need less "you still have plenty of time to figure things out" and more "James Clerk Maxwell had revolutionized science three times by the time he was your age" in my life.
June 19, 2022
James Clerk Maxwell's name is not as well known as Newton or Einstein, but that is largely because of Maxwell's modesty and the fact that his ideas were so far ahead of their time that, by the time they were proven, credit was often given to the experimenter who proved it. Yet, his work was so broad and deep that there is no aspect of science untouched by him. This book tells the story, not only of a scientist driven by curiosity but of a full human being - one who was a generous friend, driven by kindness - a deeply devoted Christian, driven by love for the Lord - and an exceptional mentor, driven by a desire to see the world's understanding of science advanced.
April 16, 2020
I like physics and I am so fascinated about Maxwell's contributions and discoveries. His undying thirst for knowledge and understanding how things work made him such an icon in the world of physics and math. One of the stories told in this book was that he spent lengthy hours reading books and other resources for him to gather all knowledge and assemble them in pieces. It really needs hard work and effect to achieve something. His story is so amazing. Very inspiring. Great book. Its an easy read.
November 8, 2017
The great genius, Maxwell, still doesn't get his due!
Maxwell is wellknown to students of science, but not quite a fashionable name to be dropped in social circles. This book tries to tell us how great he was and why he should be as widely name-dropped as Newton/Einstein/Hawking etc.
Though the book is thoroughly enjoyable (finished reading it in 3 suitings, great!), It hasn't the mettle to become a bestseller.
Let somebody write a bestseller on Maxwell! Please!
Maxwell is wellknown to students of science, but not quite a fashionable name to be dropped in social circles. This book tries to tell us how great he was and why he should be as widely name-dropped as Newton/Einstein/Hawking etc.
Though the book is thoroughly enjoyable (finished reading it in 3 suitings, great!), It hasn't the mettle to become a bestseller.
Let somebody write a bestseller on Maxwell! Please!
April 19, 2020
Worth reading
Well researched and written. Worth reading.
The Kindle version could be more carefully transcribed, small editing concerns like: all the * comments throughout the book are collected at the end on sequential pages that are not numbered, the fonts change in the middle of words, many dates contain spaces in the middle of the number for the year ...; minor publishing blemishes in a book that deserves better.
Well researched and written. Worth reading.
The Kindle version could be more carefully transcribed, small editing concerns like: all the * comments throughout the book are collected at the end on sequential pages that are not numbered, the fonts change in the middle of words, many dates contain spaces in the middle of the number for the year ...; minor publishing blemishes in a book that deserves better.
January 16, 2025
an introduction to JC Maxwell, for the scientist
The book covers the life and work of James clerk Maxwell. The author includes many details and descriptions of Maxwell’s experiments and theories that will be interesting for the amateur or professional scientist. Stories about his life, often in the words of his friends gathered from letters, outline an amiable and admired friend.
The book covers the life and work of James clerk Maxwell. The author includes many details and descriptions of Maxwell’s experiments and theories that will be interesting for the amateur or professional scientist. Stories about his life, often in the words of his friends gathered from letters, outline an amiable and admired friend.
January 30, 2019
A neat insight on the life of Sir James Maxwell, the scientist who revolutionized the way we observe the physical world with his creative interpretations and imaginative thinking.
This book focuses on two cornerstones of James life:
His scientific personality, as well as his personal life as a real gentleman with a
loving personality and utmost kindness.
I recommend it to everyone.
This book focuses on two cornerstones of James life:
His scientific personality, as well as his personal life as a real gentleman with a
loving personality and utmost kindness.
I recommend it to everyone.
October 31, 2024
Maxwell was clearly remarkable and apparently a delightful person, and the mystery of his lack of fame remains. Boring book about an interesting person, overly descriptive, and not particularly insightful in illuminating neither the genius of his theory (fields are hard to visualize and the book doesn’t help) nor the reason for his lack of notoriety.
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