This woman is a total unicorn. She understands history, she understands mathematics, she understands the science, she reveals the true scientific process, and she’s able to teach it. you don’t need many people like this to absolutely change the world and my God she’s doing it basically for free Thank you. Incredible.

Having done my honours degree at Edinburgh University 1991 995 and studied in the JCBM (James Clerk Maxwell building) and covered electromagnetism as part of my engineering degree , I was never happy with my comprehension of electric voltage ( potential difference). Years later I went back to source and read the same papers you are quoting and had my eureka moments. It still remains sad to me that coming from the home of JCM I had to figure all this out by myself years later. I reckon I'm probably the only one in a class of 100 students who ever did this ? I always intended to explain Maxwells ele tromagnetics in the way Maxwell first formulated it as it is brilliantly 'simple'. Glad to see that you have done this so well. Thank you.

I appreciate this video. I am writing this note from the steps of maxwells home in Aberdeen Scotland at 129 union street in Aberdeen Scotland ..as a coincidence!

Hi Kathy, I am an EE. I have never seen this concise and accurate history ever presented by anyone. Thanks!

Whasnt Farady and spectacular mind. Such insgight. I love your direct delivery. No circumlocution or repetition. Very clear and focused.

Feynman's lectures are great for people who already know physics. Seeing it for the first time? Depends on the student.

Heaviside is the only reason we understand Maxwell now - before Heaviside, there were 20-21 equations with as many unknowns. Heaviside reformulated these into the 4 recognized equations we use today. Heaviside was treated very unfairly, and from my recollection, this was due to his Operational Calculus. His response to their accusation that he didn't prove, mathematically rigorously, that this method worked, was along the lines of: "Just because I don't know understand how my body digests my breakfast, doesn't mean I shouldn't eat it.". BTW - it works. His efforts, along with Charles Proteus Steinmetz (almost not allowed into the USA b/c of his dwarfism), are the sole reason electricity is engineerable. Heaviside eventually go so fed up with the criticism from the British establishment, that he stopped writing. He did something like painted his fingernails and removed all the furniture from his house, and gave up...

You are the person who makes history an interesting subject because other historians focus more on politics and wars, but you focus more on physics. ❤

You are phenomenal Kathy, the research you put into your work is astounding. Thanks for putting this all together and presenting it in a fun and comprehendible way.

Hey, you don't need a REASON to mention Feynman - it's always a good thing. The man is a top hero of mine.

This is great - I just taught an intro class in E&M and leaned in a bit on the historical aspects, but there are many here I was not aware of! Great work here.

Round 2: I am watching this video again. It is an amazing synthesis of the why and how Maxwell came to his equations. Keep going Kathy. You have a very special gift in the way your explain physics. Thank you,.

One really important part of this history is the complementarity of Maxwell and Faraday. Both were geniuses but in their own ways. Faraday was a genius of experimentation and Maxwell of theory. These two were the perfect compliment of each other.

I bet the comment section is all STEM professionals. I’m Petroleum and I can’t thank Kathy enough. Your presentation is addictive. Thank you!

My wife gave the three-volume set to me for Christmas several years ago. She gave me "Feynman's Tips on Physics" a couple of Christmases later. They are my most cherished Physics books, even more than all my textbooks.

Thank you for bringing O. Heavyside into discussion of Maxwell's Equations.

Never before have I had such dry equations be brought to life with such nail-biting drama and cliff-hanging excitement. Thanks so much for this!

Kathy, I have said it before but I can't say it enough; thank you a million times for all the wonderful videos you produce and all the time and energy you put into your work. Everyone enjoys your channel and it is so needed. As you say science needs context and you are filling that void. God thank you sooo much.

It's a good introduction to a long tradition in physics, taking someone else's brilliant idea, and turning it into brilliant math. Minkowski is another classic example. I've heard Einstein quited as saying that by the time Minkowski got done with it, he barely understood his own theory.

I am an electrical engineer so of course I studied electrodynamics and Maxwell's equations. The video was very detailed and and exact. The graphics were very helpful. But I found that the discussions and derivations went by a bit too quickly. This is a subject that really needs a slower step by step derivation plus seeing and deriving it by writing the equations. But I know that you really don't want to stretch this out into too many videos so I understand why you went at the pace you did. For me as a young undergrad, the epiphany was realizing that based on these equations the speed of light through a vacuum is a function of mu-zero and epsilon-zero ie physical constants based on static measurements!!! A group of us made T Shirts with Maxwell's Equations with the words "Let there be light!" a the bottom!

- One of the things that needs to be mentioned is that the differential equations are a condensed (shorthand) form of the integral equations. If one misses that fact, one might find the equations difficult to relate to real problems. - I've heard people describe Maxwell's writing as equivalent to vector equations, but in a more awkward notation. I now see why that was said. I've never been told about Heavyside's contribution! This was a wonderful lecture.

It is an absolute necessity to go through the history to understand the development, if included in syllabus it will really put colours in the repulsive textbooks, we all have gone through hours of memorization before truly convincing ourselves through understanding, that process might be more forgiving and seeing the leaders of the fields to fumble and try and fail might give courage. Another masterpiece, thank you.

Fascinating to this old physicist. It seems I have used the equations for 40 years without knowing their real origins.

Crazy, my home tutor was just telling me about it. I'm gonna finish high school in a month (high school is 9th and 10th grade here) and he was just letting me know about some stuff I'm gonna learn in 11th and 12th grade starting from next month and this was the first thing he talked about. Basically, he went: "At present, you know Coulomb's Law right? You can solve problems with it as well. But what if, I had a metal plate, which is obviously a conductor, and insert 4 positive charges into it? The same charges would repel each other so each charge would try to maintain the best distance it can from the other three within the allotted space inside the metal plate. Now, what if I bring a point of negative charge near the plate? Of course, it will be attracted to the positive charge of the plate. But can you, at your level, measure the force it will be attracted with?" I replied, "Well, I can measure the force for each positive charge according to their distance from the negative charge and then add up the vectors." But he said, "Good idea, but in reality the number of charges won't be 4, but in the millions. What will you do then?" I could not answer. Then he said, "This is when Coulomb's Law stops working, and this is the point from where your new grade will start. This is the the point when physics has to advance, and we have to hand it over to the hands of a new boss. Do you know his name?" "No, I don't think so." "Gauss. Remember it, because when you'll understand Gauss' Law, you'll stop depending on good ol' Coulomb." Then he proceeded to show me the equation and say some stuff about loop integrals that flew over my head but nevertheless, I was very excited to learn about it. It all just happened an hour ago too lol. What a coincidence that my favorite physics KZfaqr would talk about it so soon! Thanks!

I really like the way this shows how the thinking evolved and, in particular, how the meaning of the equations and constants gradually became more closely linked to the phenomenon being modelled.

A brilliant exposition, but as a non-mathematician there was some heavy going and much scrolling back. How lucky we are to have someone who knows the subject inside out and can also express it so lucidly and with such enthusiasm.

What a simpathy and pleasure in teaching physics. Wish you were a professor of Mine. Congratulations.

Based on this video lecture, I purchased the kindle version of the book: "Lightning Tamers". This lecture was, to me, worth the purchase price of the book.

Kathy has given us a wealth of knowledge worthy of any college course for FREE! A masterful job to say the least.

Maxwell is also a top hero of mine - maybe even above Feynman. The degree to which Maxwell's work has impacted the world we live in is just impossible to overstate. Just look around you, and electromagnetic phenomena, under our mastery, is EVERYWHERE. It's hard to even imagine life without it now.

Thank you for your excelleant work again on history of the Physics/Maths for important discoveries/inventions in these areas. Maxwell equations for fluid-dynamics/heat-transfer/electricity/magentism/etc are one of the least understood by majority of engineering students (as most of them are not exactly aware about the equations that are used in textbooks). Your excellent series on these topics gives students/learners about how these equations are derived in first place and amounts R&D was being done in non-internet-era (with limited sources of information/equipments) and still those pioneer scientists have succeeded in their discoveries/inventions despite all odds in those times with so many iterations(that sometimes span over couple of years). It also reminds how lucky we are in this modern internet-era to get these information at finger-tips. Wish you great success in your endeavours and your book sales. Also I wish that most of the universities and colleges also teach the history/stories behind these discoveries/inventions (so that students/learners can understand better )

Faraday and Maxwell, the experimentalist and the mathematician, bound together over their love of electricity, changed the world forever.

Thank you Kathy! I am a high school Physics teacher and have longed for videos like this to give my students to understand the historical developments in Physics. Great videos!

The torsion balance is really a marvellous invention. It's so simple, but yet precise enough to measure even the very weak gravitational constant (this was first done by Cavendish in 1798) and even the yet most precise measurement of the gravitational constant was done with a torsion balance.

Kathy, you have done an outstanding job transporting our imagination back to 19th century and allowing our minds to grapple along with Maxwell the scientific questions about electricity as viewed through glimpses of primary publications and contemporaneous discourse. Viewers should not expect to learn Maxwell's equations from the lecture or use it as a substitute for a textbook. Instead the lecture delights, enriches, and deepens, our appreciation of the Maxwell equations. Feynman recommended that , and you have done a marvelous job taking up Feynman's challenge, which reflects truly your deep love for both physics & history. Well done!

My grandmother was born in 1868. Just three years after the American Civil War. The war that Fiineman thought was insignificant compared to Maxwells equations. That hasn’t been all that long ago. Look at what has been discovered. My mother, her youngest daughter, told me she was offered a scholarship to the University of Arkansas. That just didn’t happen to women back then. Her father refused it. He didn’t think women needed an education. A lot has changed since then.

After Newton and Einstein, Maxwell should be regarded as one of the greatest scientists. I really enjoyed your chronological history of Maxwell's equations that now a day are integral part of technology.

If only every lecturer had Kathy's articulate, charismatic and enthusiastic delivery, along with her brilliantly organised and researched unfolding of events, then physics would be more popular than reality TV. Thank you Kathy!!

Not gonna lie. When I saw your slide listing the 5 parts, I got hopeful for a 5-video series on this. Excellent work!

Great video Kathy! Am looking forward to the rest of this series!

Thank you Kathy for another wonderful video. As an EE grad (1981) we were taught Maxwell's equations. But digging in, and understanding them deeply were graduate courses. Your videos have brought me a much deeper understanding of them. It's great to see how they grew and changed over time and its much easier to see what they mean when seen from this historical context.

Thank you Kathy for presenting this historic physics lesson. Very well done!

I will likely never get a tattoo, but if I do, 100% chance it will be Maxwell's equations. Beautiful timeless perfection. Celebrate genius and mental effort.

I have acquired a fondness for Faraday and Maxwell since we have initiated a TMS program (Transcranial magnetic stimulation). Your teaching has illuminated an amazing time. It is remarkable that these men just intuited these relationships. Keep it up!

A grain is a unit of measurement of mass and is equal to exactly 64.79891 milligrams. It is nominally based upon the mass of a single ideal seed of a grain. Not a grain of sand, which is a tiny fraction of a milligram. Great video. Love your stuff.❤

Well you did it again, you have blown me a way. I love the lucidity with which you present the subject.

It's amazing how Faraday thought of light related to electromagnetic lines of force.

way back in the 70´s as a Physics teacher's assistant I came by I guess one of the first books compiling Feynman's lectures now I see there is a collection of them. I wish I had that chronological way of studying physic as you do in your outstanding lectures, would love to hear from you how did Lord Kelvin came up with his "thunderstorm" machine, same with mr wimshurt´s high tech contraptions even to our times

If you haven’t seen it already, please read “Oliver Heaviside: Sage in Solitude” by Dr. Paul J. Nahin. It is a wonderful historical account of Heaviside. I was fortunate to be able to take classes from Dr. Nahin when I was in undergraduate engineering at UNH. He’s a fantastic story teller and gifted author…

15 minutes in, I’ve already spent almost three hours within this video - thanks to rewinding mercilessly, pausing and reading nearly all the text attached to the video, the normal Internet rabbit hole tangents, and my favorite - cracking open my Ohanian Physics text from 1989! Incidentally, with not a little help from Kathy, the Ohanian makes considerably more sense now as to when I was 19. This channel is bad for my sleep hygiene.

Fascinating video again Kathy

Thank you. As a chemist, I took engineering physics. Many times I was lost in the mathematics. It is a struggle to understand electromagnetism. Thank you for the assistance. A old retired chemist.

This was really good! I wish we had more of this historical motivation in my physics degree. Looking forward to future parts!

Kathy, thank you for your video. Being an EE DSc, I cannot help being less than passionate about Maxwell's equations

Havent studied electric theory in years ...now my head hurts.Thanks Kathy

Kathy, that is an amazing tour de force of scientific virtuosity. You have done all the heavy lifting. I sense much love in this. Love for the subject and love for the students. This is really great work!

I’ve been waiting for a KZfaq video on the history of Maxwell’s equations. We are lacking the historical basic measurements driving most of physics. So much missing from physics textbooks.

Amazing! I'm very excited for this series!

IIn our present time , we don´t have time to going deep , We just took for grant what many genius made with very hard work. History came to shows that there is no miracles , just hard work. Thanks teacher.

Thank you for the video Ms. Kathy! Maxwell was a genius on the par of Einstein. His equations were too difficult to be grasped by any scientist at the time, and Heaviside provided a viable description accessible to many. You can learn Maxwell equations, but understanding the real meaning of how energy propagate thru empty space - is quite a task, which requires some dedication at the beginning.

excellent video, anxious for the next of the serie :)

14:19 - the slickest edit I've ever seen. :) Thank you so much for this fantastic video Kathy, you're a treasure!

Thank you so much for doing these videos. Most of us have studied these things from the theory side but it is so much fun and I think important to learn the history also and you do a great job presenting that.

I'm so looking forward to the next video already!!!

I loved watching those lectures. His style of teaching was amazing, just like yours.

Had to pause at 2:47. You are truly a gem Kathy. I have Feynman's lectures and consider them to be the best material there is. Throughout your videos, I know that you are the most suitable person to take this challenge of doing a series of videos and succeed. Best wishes, Erik. I wish I had a teacher like you. I had to find out all the beauty by myself years after "formal education" age. Anyway, I am humbly grateful and hope that your channel, your excellent videos, will be the source (among other) for people in their curious "young" years, to find here. I wish all this was available during my years of University, and I mean other channels on YT, not just yours. EDIT: I am grateful for understanding the English language, for having access to the Internet and living a care-free life in peace, freedom and prosperity in central Europe. I am pretty privileged, I know.

Many years ago I bought that set of books, inside the box there you find the tape recording, cassettes, the popular variety of tapes were C60 aahh... these tapes are kind of behind the times, not the books.Thank you for all these videos!

Very nice. I look forward to the rest of this series! Heaviside is one of my intellectual heroes, so it is always exciting to see him get some credit for his work on Maxwell's equations 🙂

I’m really enjoying your videos; I especially like the way you (for want of a better word) often “deconstruct” abstruse concepts and the degree to which you contextualize STEM subjects historically! Great stuff 👍

Wonderful to see you back Ms. Kathy with a fascinating subject. Congrats on the 100k subs too.

Just started watching the video and I already love it!

Your work is gold! Thank you

hey Kathy just stumbled upon this video and learned about your channel. God bless you, great work

Thank you Kathy, this was great, I enjoyed every minute of it. Really looking forward to the next one, Quaternions, Heaviside etc.

Kathy, I love your videos, they are so good!!!, you put all your heart to share this wonderful physic world. thanks so much for your work, you are absolutely AMAZING!!

So glad i got this channel recommended

Reading his actual text (26:33) cleared up my understanding of his displacement current. It is a transient! I had assumed it was a steady state current. Thank You for a GREAT video!!

Excellent breakdown.

Absolutly brilliant😀😀 I’m an economist with interest in innovation. The creative process that you describe have far reach beyond physics.

She is a treasure ! Thank you Kathy!

Hi Kathy. Have been looking forward to these videos. I hope you get the time to tie the four Maxwell equations together at the end of this series by talking about the electromagnetic tensor. Specifically how to get the Maxwell equations from the EM tensor always seems to me a lot like pulling a rabbit from a hat using only first derivatives. This rabbit/ hat way of writing the Maxwell laws in an unbelievably compact form was never covered in my own undergraduate physics course. I suspect they decided that the unit already had too high of a failure rate and adding in even more mathematics would not have worked out so well. I do not share that particular view, I think it is absolutely beautiful and I wish more students had the pleasure of seeing what looks like an empty hat and then seeing the rabbit emerge. This is undoubtedly a lot to ask of you. For one thing, history aside, for the most compact form of writing out the derivatives would require a discussion of Einstein notation and possibly a discussion on the geometric meaning of the Bianchi identity (and what an identity even is) but I think the payoff might be worthwhile if only because it demonstrates just how compactly Maxwell's equations can be written when you get them into another form and, moreover, how the four Maxwell equations can be doubly paired and in a way you might never suspect, by a complementary set of operations involving only first derivatives of *E* and *B* field terms, in Cartesian coordinate form, with respect to space and time. Either way, thanks. Your work is wonderful and, as always, your passion is infectious.

Excellent Presentation!

Thank you so much for this incredible video. it is so well thought out, clear and captures your attention from start to finish!

hi kathy , i am begining my journey in physics and your videos are really very much helpful , if i will do some groundbreaking discovery discovery in physics in future then surely your lectures will be an important part of it

What a wonderful video. I appreciate the energy and intelligence you bring to the table. Subscribed.

I love your videos, Kathy

Great video. I love how you explain everything.

I Can't wait for the next episode !!!

Can't wait to devour this series ... thanks a lot !!

Wow! It's fantastic point of view on the way of learn sciene. So easy and relaxed to talk about the logic of physical processes. I listen with pleasure and great interest. Thank you. Live and develop in a happy life )

Fantastic Kathy!

I'm pretty old now, but back in my twenties, it was a primary goal of mine to develop an appreciation of Maxwell's genius. Now I have a place to start. Thank you!

Just wonderful Kathy!

So at this point here when the Blacksphere has used all the E available the fields lose strength and your disc galacty change the shape of the galacty changes do to the loss of strength the equator of the sphere loses its strength perfect perfect I knew it. You have made me very happy today Kathy thank you.

I think your videos are amazing. Thank you for what you do.

This was great because there's SO much to get our teeth into - (I actually don't have any teeth but that won't stop me trying) - There are questions I've always wanted to ask but never dared - and STILL daren't - even though I've seen other people ask the same question and get rather, err, unusual answers that sounded rather like they didn't know either but merely did their best to pacify the enquirer. Well this video, if I watch it a FEW times more, sounded like it probably contained the answer to our question, if only I can stay focused when it gets more involved. In the meantime I thank you for painting a really good picture of how all these discoveries came about - the nearest thing to being there. Thank you.

Congrats on getting to 100k! My wife and I love your videos! I studied physics in undergrad, but my professors never spent much time putting discoveries into context or explaining how many failed hypotheses are explored on the road to each great discovery. Your videos humanize the great scientists as well as the process of science, which makes a career in science seem much more attainable. Anyways, thanks and congrats.

“Di…2…2 electrics…” as lightbulb goes off. Thank you, Kathy.

Great lecture,

- ANOTHER FANTASTIC VIDEO - as always :) - Having a formal education in electrical engineering, and being a self-taught math teacher (by nature/profession), and a lover of history, your subject matter, and presentation are richly appreciated. - Now, as for quaternions, I've also been a 3D animator, where me initial exposure to quaternions arose (for rotations). And, I've heard that Maxwell's Equations were originally written in the form of quaternions - so, I was excited to get the details of exactly why/how... only to find I will have to wait for your next heroic effort! So, I await in giddy antici...pation :) ...