Greatest Physicists #3 - James Clerk Maxwell

#3 - James Clerk Maxwell


James Clerk Maxwell is my favorite physicist. This site takes its name from a wise thing he once said: "In every branch of knowledge the progress is proportional to the amount of facts on which to build, and therefore to the facility of obtaining data." For all the volumes written about the philosophy of science, that sums it up pretty well. Is it built on observable facts and empirical data? If so, it's science. Otherwise it's not. Anyone, however, can come up with a clever thing to say. Almost no one in history has come up with as many brilliant contributions to the modern world as Maxwell. I'm going to let a few more brilliant men do some of the work for me, as whatever I say is not really going to cut it when describing this level of accomplishment.

From a long view of the history of mankind -- seen from, say, ten thousand years from now -- there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial insignificance in comparison with this important scientific event of the same decade.
- Richard Feynman

He was born in 1831 and had a fairly standard childhood. It was always clear he was a particularly bright child. By the time Maxwell was 16, he was enrolled at the University of Edinburgh, where he conducted experiments involving the polarization of light. No one yet new was polarization really was. For that matter, no one knew what light was either. After leaving Edinburgh, he went to Cambridge where he began to make a name for himself as a mathematician of considerable talent. He published his studies of the properties of certain curves and began his study of color and light. His work attracted great interest, he lectured at the Royal Society, and shot up the ranks and became the chair of Natural Philosophy at Marischal College in 1856. Natural philosophy was in those days the name for what we'd today call the physical sciences.

He set to work fulfilling his new responsibilities, and among his first accomplishments was a mathematical exploration of the properties of the rings of Saturn. He showed that there was really no possibility other than that the rings were composed of small independent particles orbiting the planet, and about a century later this was proved by the flight of the Voyager probes.

Most of Maxwell's fame very justifiably derives from his contributions to electromagnetism, but almost casually he made great advances in a number of other fields. There's thermodynamics in the form of the Maxwell-Boltzmann distribution and the Maxwell relations. There's some of the first real treatments of dimensional analysis. There's foundational papers in control theory. He took the first color photograph. You name it in physics; Maxwell may well have been involved.

Maxwell's equations have had a greater impact on human history than any ten presidents.
- Carl Sagan

Maxwell was the first to unify the theory of electricity and magnetism in one coherent whole by writing down these four equations, for each of which I'll give a very brief synopsis:

Electric charges create electric fields.

Magnetic charges would create magnetic fields if there were such thing as magnetic charges. But there aren't.

A changing magnetic field creates an electric field without the need for charge to be involved.

A changing electric field creates a magnetic field without the need for charge to be involved. Electric currents also create magnetic fields.

Now let me dispel some of the "physics legend" version of this story. Maxwell didn't write these equations in this modern form. He wrote them in a version which more or less wrote the curl operator in a less compact way involving each axis separately. Heaviside first wrote them in their modern form. And Maxwell didn't invent these equations individually, he only added the electric field term to the last equation.

That, however, was more than enough. With that modification he was able to find the wave solutions to this equation and deduce that electric and magnetic fields could mutually produce each other and propagate through space. He found that the theory predicted those waves would travel at about 300,000,000 m/s, which happened to be the speed of light. This let him make the bold inference that light is just electric and magnetic fields interacting in a particular way. As indeed it is.

The work of James Clerk Maxwell changed the world forever.
- Albert Einstein

Maxwell was ahead of his time. Unlike Newton's laws which require an absolute reference frame, Maxwell's equations keep the same form in every inertial frame. They don't even require modification to work with Einstein's special relativity. Maxwell wrote the first relativistic field theory and didn't even know it. Today we can express this more clearly (if you're familiar with tensor notation) by boiling down his four equations into two.



For all that and more, James Clerk Maxwell takes a well-deserved place among the pantheon of the true greats.

The list so far (click the category name for links):
3. Maxwell
4. Faraday
5. Feynman
6. Rutherford
7. Schrodinger
8. Dirac
9. Thomson
10. Pauli

Not-strictly-physicist honorable mentions:


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Actually you can also write the last equations without those indices. That makes them even more compact.

Sagan's quote is President-dependent. Adding Franklin Roosevelt and Bush the Lesser makes for a ponderous counterweight. Imploding the world's economy has been done, as has human slaughter at the same scale. The impossibility of Social Security and Medicare for 70 million US Baby Boomers added to global financial meltdown, energy supply contraction, the SOP remedial war pre-lost... and Enviro-whiner hegemony assassinating every engineering solution sums to way bigger stuff.

I wonder what the top ten living physicists would have discovered had they lived in different eras.

I also wonder how John von Neumann would have fared if he had been encouraged early in life to study theoretical physics exclusively.

The list so far (click the category name for links):

This article isn't in your Greatest Physicist category (and neither are your honorable mentions).

You have a touching affection for British physicists: Maxwell, Faraday, Thomson, Dirac is 4, I'm guessing Isaac Newton might make it into your top 2 so say 5 out of 10. And that's without counting Rutherford, who was born in New Zealand but did his big stuff in Cambridge. Does this indicate a bias (conscious or unconscious) on your side or is it an indication of excellence in British physics?

I wonder what names a similar list of a French or Italian physicist would have. Physics may be more culturally bound than a lot of physicists would like to think!

"You have a touching affection for British physicists"

I think it's because Britain has produced an inordinate amount of excellent physicists. If I were ranking great mathematicians, the list would be dominated by the French along with a couple of Germans.

#3, you're right. I stated that fairly inartfully. What I mean is that Maxwell's theory requires Lorentz transformation to shift between frames; Newton's theory does not.

#5, thanks for letting me know about the category problem, I'll get those links fixed in a little while.

A big part of why Britain has produced an inordinate amount of excellent physicists is because they have had conditions conducive to producing excellent physicists for longer than any other country. Britain has been among the world's top economic powers for most of the last 400 years, and politically stable from Newton's lifetime onward. Thus smart people with the ability to do physics were able to do so, during a period when there was much fundamental physics to be done. Compare with other countries like Germany (which only got its act together around 1870 and started falling apart again in 1933), Russia (the Soviet Union produced a number of top-notch theoretical physicists but not so many highly ranked experimentalists, and many of the former left after the Soviet Union collapsed), China (until recently too poor to have a significant science program, and has had many bouts of political instability in the last 200 years, though many Chinese have had productive scientific careers elsewhere), India (has produced a few good home-grown theoreticians like Bose, but again most of the productive Indian scientists work outside India), or the US (which only became a world economic power in the 1890s and only produced a handful of excellent physicists before the 1930s), to name a few.

By Eric Lund (not verified) on 19 Nov 2008 #permalink

I believe that Maxwell was responsible for writing down Faraday's Law in a mathematical way. Faraday didn't do mathematics, and only expressed his law as a relation between EMF and changing B -- at least as I understand the history. But since I haven't studied that history in detail, I'd appreciate any information about the origin of the equation in the form Maxwell used.


If you have never looked at Maxwell's equations without vectors (in our modern notation) and the vector operators, you really should see what a god-awful mess they were. Most libraries have his book in some form.

Uncle Al, I'm sure Roosevelt was President long before Sagan made that observation. (You are excused.) Might even have included Nixon. In any case, it remains true no matter what combination of Presidents you put together. Maxwell provided the first unified theory, stimulating an entirely new vision for what goals physics should have, and made possible the telecommunications system that Bush and Nixon were listening to! Without Maxwell, there would have been no Watergate break in to plant listening devices. Well, someone else would have done it eventually....

Oh, and Maxwell wasn't British. He was Scottish. ;-)

And don't forget Gibbs, the American who contributed significantly to vectors in the form we use them today.

I am so excited to find out who the next two are.

I love top 10 lists, but have never seen one on physicists. You next post should be on top 10 duets of the 70s ... Kiki Dee and Elton John's "Don't go breaking my heart" has to be up in top 5.

"In every branch of knowledge the progress is proportional to the amount of facts on which to build, and therefore to the facility of obtaining data."

Something to think on when people tell you memorizing facts is bad.

James Clerk Maxwell is my favorite physicist."

So how come he gets listed as #3?!!

On a serious note, it would be nice to have links from the current item back to the earlier ones which we may have missed.

Ian: that's what the category tags are for. You can see all of the relevant posts by clicking on the "Greatest Physicists" category tag at the top. (Though perhaps Seed should modify their template to make it more obvious that the category tags are clickable links.)

By Eric Lund (not verified) on 20 Nov 2008 #permalink

Before we find out if Einstein or Newton is #1 (have I spoiled it for anyone?) let me give my totally useless opinon that Newton is marginally the greater. He not only had to do the physics, he had to invent a new branch of mathematics to do it.

Einstein was a brilliant physicist, but he had help with the maths for general relativity.

However, I'd wouldn't object to a joint No. 1!!!

Another reason for British dominance in physics was its imperial and class system. This provided first-class educations to bright men from Wales, Scotland and Ireland, and the wrong parts of England, without matching job prospects at the highest levels of government. This prevented those bright men from being sidetracked into unproductive careers as Government ministers.

By Bob Hawkins (not verified) on 20 Nov 2008 #permalink

Since it's obvious who 1 and 2 would be, I've been waiting for #3 to pipe up.

There's a guy who built (AFAIK) the first effective quantum field theory, the first theory of weak nuclear interactions, elucidated the "bizarre" half of the spin-statistics theorem, got half the particles in the universe named after him, discovered transmutation of the elements, discovered slow neutrons, and initiated the first nuclear chain reaction.

For someone who won a Nobel Prize for his theoretical work, then carried out the experimental work that was the basis of the Manhattan Project, it's disappointing not to see Enrico Fermi anywhere on this list.

Personally I'd put him ahead of Schroedinger or Thomson for sheer awesomeness as a physicist.

By Andrew Foland (not verified) on 20 Nov 2008 #permalink

About the same time I read this, I got one of amazon's "you might be interested" emails, recommending Daniel Fleisch's "A Student's Guide to Maxwell's Equations." The reviews at the site are almost too good to be true, and I was wondering if you knew anything about it.

By Roger Sweeny (not verified) on 22 Nov 2008 #permalink

#2, Sagan may have meant 'greater' as in better, not larger. Suggesting there's a greater number of positive(or at the very least, benign)results that stem from Maxwell's contributions than from those of any ten presidents.

#14, He is #3 because the topic is 'greatest' physicists, not 'favorite' physicists.

Deep thinking does not necessarily require overlooking the shallow obvious.

Sam, it appears that YOU might be the one holding the prejudice or bias, and I think you just got called out on it, what is your response?

what about nikola tesla
even greater then faraday and maxwell

By Anonymous (not verified) on 17 Oct 2009 #permalink

James Clerk Maxwell is underrated, all the things engineers like Tesla and others did is based off the science from Faraday and Maxwell

"Maxwell's equations have had a greater impact on human history than any ten presidents" - Carl Sagan

As for changing the world, Maxwell transformed it

By theOneWithoutASecond (not verified) on 16 May 2010 #permalink