Ohm's Law: History and Biography
Vložit
- čas přidán 22. 08. 2021
- A biography of high school teacher Georg Ohm. How Ohm wrote his law, why it was hated and how it become accepted in scientific communities.
Links:
My mailing list:
kathylovesphysics.ck.page/wel...
My Patreon Page:
www.patreon.com/user?u=15291200
The video about Faraday where I mention Wheatstone's fear of public speaking:
• What is Light? How Far...
As usual, a big thank you to the fabulous Kim Nalley for singing "electricity" and some background music. www.kimnalley.com
Karl Christian von Langsdorf to Johann Ohm (1804) found in “Obituary notices of deceased Fellows: George Simon Ohm” Proceedings of Royal Society of London (Jan 1, 1856) vol. 7 p. 599
According to Jungnickel, C and McCormmach, R Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, Volume 1 (1990) p. 52
Ohm, G “Ueber Elektricitätsleiter” Journal für Chemie und Physik (herausgegeben von Dr. Schweigger u Dr. Meinecke) vol 44 (1825) p. 12
Poggendorf letter to the editor quoted in Schagrin, M “Resistance to Ohm’s Law” (Feb 4, 1963) American Journal of Physics vo. 31 No. 7 p. 542
Schagrin, M “Resistance to Ohm’s Law” (Feb 4, 1963) American Journal of Physics vo. 31 No. 7 p. 545
Ohm, G “Bestimmung des Gesetzes…” Journal für Chemie und Physik vol. 46 (1826) p. 25 translated and found in Schagrin, M “Resistance to Ohm’s Law” (Feb 4, 1963) American Journal of Physics vo. 31 No. 7 p. 543
Georg Ohm in 1826 translated and quoted in Appleyard, R Pioneers of Electrical Communication (1968) p. 199
Jungnickel, C and McCormmach, R Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, Volume 1 (1990) p. 53
Quoted and translated by Tyndall, J “Reports on the Progress of the Physical Sciences” London, Edinburgh and Dublin Phil. Mag. [Forth Series] (May 1852) p. 322
Schagrin, M “Resistance to Ohm’s Law” (Feb 4, 1963) American Journal of Physics vo. 31 No. 7 p. 540
Found in Lloyd William, T Physics, the pioneer science (1959) p. 668
Dr. J. Lamont “Obituary notices of deceased Fellows: George Simon Ohm” Proceedings of Royal Society of London (Jan 1, 1856) vol. 7 p. 600
According to Jungnickel, C and McCormmach, R Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, Volume 1 (1990) p. 57-8
Sturgeon, W “Description of an Electro-magnetic Engine” The Annals of Electricity, vol. 1 (October, 1836) p. 78
Jacobi, M “On the application of Electro-magnetism to the moving of Machines” (April 1835) The Annals of Electricity, Magnetism, and Chemistry (Oct 1837) p. 422
“On the translation of Foreign Scientific Memoirs” British Association for the Advancement of Science Report of the Annual Meeting vo. 10 (1841) p. 446
Bowers, B Sir Charles Wheatstone FRS (2001) p. 102
Taylor, R Scientific Memoirs Selected from The Transactions … vol. 2 (1841) p. 401
Copley Medal 1841 “George Simon Ohm” The Royal Society royalsociety.org/grants-schem...
Wheatstone, C “The Bakerian Lecture” (June 15, 1843) Philosophical Transactions of the Royal Society vol. 133 p. 303
Found in Alois, K Christianity and the Leaders of Modern Science (1911) p. 132-3
Dr. J. Lamont “Obituary notices of deceased Fellows: George Simon Ohm” Proceedings of Royal Society of London (Jan 1, 1856) vol. 7 p. 602
Report of the British Association for the Advancement of Science (1865) Foldout between p. 348 and 349
If you would like to know more and how Ohm and the rest fit in the history of electricity check out my book: "The Lightning Tamers" by Kathy Joseph amzn.to/3I7N4mq
It’s shocking that Ohm would have had resistance to his theory.
Shocking
Great pun!
I guess the established scientist’s weren’t all to amped up about the new theory
Ohm my!
So much tension !
Dear Kathy, I am 72 and a retired mathematics teacher in Germany.
I love your videos and your engaging way to illuminate physics to us historically.
My native language is German.
I assure you that it is not so important to pronounce the German names correctly.
Keep up the good work. You enrich all who want to learn. Thank you!
Thank you so much and especially thank you for forgiving my bad pronunciation I am trying it’s just very difficult for me for some weird reason.
@@Kathy_Loves_Physics The easiest and fastest way is to use Google translate's text to speech function. Just type in It is fairly accurate or german words, so I highly recommend you to chekc it out. Love your videos!
Ja, wohl. However Kathy also has a habit of mispronouncing many less common English words. (I'm American and I assume from her accent that Kathy must be North American. There are differences in pronunciation between British English and North American, but that's not the issue. ) I agree, Kathy's videos are fascinating and worthwhile. I'm a 71 Electrical Engineer, and enjoy her elucidations of the history and personalities.
@@Kathy_Loves_Physics Many "science type" people (my wife is one) have an immense vocabulary that they learned at an early age from reading, not from listening. They will thus have invented their own pronunciations of certain words in English and other languages. My wife, a chemist, had to learn German so that she could read Beilstein (the famous compendium of organic compounds). Her pronunciation of German is atrocious, scheußlich, grauenhaft. I, on the other hand, learned German poetry and songs, and put much effort into correct pronunciation. Now as I learn Spanish I find it very easy to pronounce it correctly, to the point that I am asked, "How long did you live in Mexico?" (Never been there!) Now I must put that kind of effort into grad, div, curl and Maxwell's equations that I never learned well so many years ago.
Davide?
My father taught me Ohms Law on a long car journey we undertook when I was about 12 years old in 1952. I've used it all my life as an electronics engineer. It's so simple and elegant and I can't believe how it was denigrated by Ohm's contempories. Thanks for another excellent and entertaining lecture/video.
The part of Oersted’s discovery that I love is that he was a classroom teacher, as I was for 40 years. He was going to demonstrate to his students the prevailing theory of the time that Electricity and Magnetism were two entirely different phenomena with no connection to each other. Didn’t quite work out the way he expected!
He was a high school teacher but it didn’t go down exactly like that I was actually trying to link electricity and magnetism for eight years I think at the time. I have a video about him of course, you should check it out
@@Kathy_Loves_Physics you were trying to do that?
:D
Electricity and magnetism are two separate phenomenon that influence the ether in very similar manners but are distinctly separate after all magnetism is structural and is produced by the structure of the compound, electricity is motion of the etheric fluids derived from luminoferous ether.
@@sebastianstewart6894 ether isnt a thing, I have to disappoint you
@@lugyd1xdone195 yeah, SS is seeing the ether bunny.....
"Wheatstone was a bridge between the tinkerer and the scientist" Very suitable for the inventor of the Wheatstone Bridge. Max Plank famously said that science advances one funeral at a time.
I never knew that quote, I love it. (I also am a big fan of Max Planck, I’ve made think five videos about him and I’m planning a book about him and his influence).
@@Kathy_Loves_Physics Max Plank was the first famous physicist to champion Einstein, I am given to understand. Just discovered your channel. Possibly nothing interests me as much as the history of science. The flat Earthers have gotten me thinking about how a layman can prove a spherical Earth to a skeptic. Not easy at all. The common description of ships disappearing over the horizon only proves the curvature of sea level.
"...Charles Wheatstone who bridged the gap..." had me genuinely laugh out loud.
was looking for this... and I am not disappointed... Great pun hahaha
Yep, I paused the video and came looking for the comments! 🙂
72 years old with many years in electronics - I am impressed. Great presentation!
Wow legends
72 years you say, so you must have heard of William Shockley
Mam, I am a high-schooler from India. This was the very first video that I had watched in your channel an year ago when we had Ohms' law in our syllabus and I was mesmerized! My book does not talk about history but your videos do! This makes me love physics even more. Been binge watching your videos ever since, Thank you mam!
Why didn't I have teachers like you in school? You are a brilliant educator and story teller.
Who's keeping humanity from learning the nature of the Universe?
A school is not a place for telling stories. The history of science is an amazing part of knowledge, but there is no room for it in syllabuses. It's better to teach schoolkids how to use Ohm's law than to tell them how it was disapproved and appreciated years later. One day is only 24 hours long, kids spend several hours at school, so this time should be used effectively.
Fortunately, we have Kathy and YT, so those who want learn about the development of science, can click whenever they want and listen at their convenience. One remark here: schoolkids should not watch Kathy's videos in classrooms :-)
Wow, such a good story. I always assumed Ohm's Law was one of the first well established facts of electricity, just because of its simplicity. I won't take that law for granted any longer!
OHMS LAW IS SIMPLE ON DC ,,,, on AC THE THINGS BECAME UGLY because in DC you work with R , on AC you work with Z ,,,, IMPEDANCE ,,,, not RESISTOR
@@lesstime1678 - Ohm's law is simple with AC, but who was the one that figured out it was simple?
Ambient temperature C/F is a factor of conductivity and resistiviity.
@@jrstf Ohm’s law is actually a bit more complicated with AC than DC. With DC, except for the moment of turning power on or off, the resistance to current flow, and thus the current, is steady because the voltage is steady. With AC, specifically with sine waves (where voltage and current vary in proportion to sin(2•pi•f•t), where f = frequency in cycles per second, or Hertz (Hz), and t = time), there are three factors other than voltage that affect current: resistance, inductance (the effect of a changing magnetic field on the conductor from which it is generated, which “resists” changes in current), and capacitance (the effect of an electrostatic field to “resist” changes in voltage). The latter two create an effect called “reactance,” which like resistance is measured in ohms, but they cannot be simply added!
A theoretically pure inductor has a reactance that varies with frequency, XL = 2•pi•f•L, where L = inductance in henrys (after Joseph Henry). This inductive reactance restricts the AMOUNT of current, but it also causes the graph of current vs time to LAG the voltage by 90 degrees, or 1/4 cycle. So current is at a negative maximum when voltage is crossing zero from negative to positive, going from negative to positive when voltage is at its positive peak, at its negative peak when voltage is crossing zero from positive to negative, and crossing zero from positive to negative when voltage is at its negative peak. Therefore, resistance and inductive reactance are added as 2-d vectors (aka phasors, which are not Star Trek weapons) phased 90 degrees apart, with the phasor sum being the diagonal, having BOTH intensity and phase angle (between zero and 90 degrees (or -270 degrees). For this reason, actual inductors (if capacitive reactance is insignificant) produce a resultant “resistance” with a phase angle between zero and 90 degrees. And the higher the frequency, the more reactance, while resistance remains steady (except for “skin effect,” which keeps current from flowing in the interior of a conductor at higher frequencies).
A capacitor, on the other hand, does the opposite: ignoring the resistance of actual capacitors, the CAPACITIVE reactance causes current to change 90 degrees AHEAD of voltage, and restricts the flow of AC in a way that is INVERSELY proportional to the frequency (actually, current doesn’t REALLY flow across a capacitor, since it is an open circuit, but the electrons in each plate can “feel” the attraction or repulsion from the opposite plate, so variations in current flow can pass through). This capacitive reactance XC, also measured in ohms, is at a phase angle of -90 degrees, or 270 degrees, and its magnitude is 1/(2•pi•f.C), where C = capacitance in farads (after Michael Faraday).
So to combine resistance and reactance in series (or in the same component, known as “parasitic” resistance, capacitance, and inductance), to get the phasor value Y, aka “impedance,” just sum up the values AS PHASORS: Y^ = R^(0 degrees) + XL^(90 degrees) + XC^(-90 degrees) AT A SPECIFIC FREQUENCY. To combine these values in parallel, add their reciprocals in mhos (or siemens). The reciprocals have unique names: the reciprocal of resistance is “conductance,” the reciprocal of reactance is “susceptance,” and the reciprocal of impedance is “admittance.”
Note that at low frequencies, inductive reactance is smaller (for DC, it’s zero) and capacitive reactance is larger (at DC it’s infinite!), so the current is small and lagging behind voltage; at high frequencies, inductive reactance is higher, and capacitive reactance is smaller, so the current is small and leading the voltage. At some in-between frequency, inductive and capacitive reactance cancel out, and the current is at a maximum and in phase with the voltage. This is called RESONANCE, for a series resonant circuit. Note that the voltages across the inductor and the capacitor are MUCH LARGER than the power supply voltage, and are 180 degrees out of phase with each other!
A common mnemonic to remember these phases is the phrase “ELI the ICE man,” meaning “E (an alternate symbol for V) in an L (inductor) leads I (current intensity), while I in a C (capacitor) leads E.”
One reason Edison distrusted AC was the more complex math; he was, after all, a self-educated genius tinkerer!
@@colmcillegardner2144 - That is true but is not related to Ohm's Law.
This is the most detailed and beautifully presented story about Ohm's law I've ever heard. Thank you for your hard work.
Thanks
WELL SAID...I TOTALLY 2ND THAT!!!
@@Kathy_Loves_Physics I love the way you explain a lot with your hand gestures 👍👍I tried going into portrait mode to see more.😉😊
A bit sad, but ended happily. What tickled me is that Mr. Ohm had fans & superfans that kept promoting his theory. So glad he was vindicated when he was still alive, and even showed his appreciation publicly.
Anyone who learns science history should hate how scientism adepts distort science, pretending stories like this (or Boltzmann's, which did NOT end happily) never happened because science is Temple of Purity where everything and anything is always rationally analized on its own real value
Great video. I love Ohm's law. It can be succinctly summarised as it takes 1 volt to push 1 amp through 1 Ohm. That really helped my understanding of circuitry and current flow without the need to use a multimeter. I was heartened to hear that Ohm's law first gained widespread use in my country England whereby it had been dismissed on the mainland previously. Really interesting video!!
Just goes to shows how difficult it is for scientists to sometimes be accepted in their own time and yet be praised after they are dead. Artists seem to be in that same league. Ohm’s law is so ubiquitous today as EE’s we hardly give it any notice. That is a shame for Georg Ohm and also Tesla who created the ground work for high voltage transmission lines across vast distances, Thank you Mr. Ohm for your contribution.
Well: No engineer thinks about ohms law in practice, as it is to intuitive, obvious and simple to call out as such.
But many calculation have a result or and input in ohm - so his name is honored a lot.
Tesla on the other hand got the short stick, but that makes him the hero of all nerdy underdogs.
Worse yet, as we see in todays cov id crisis, politics plays a huge role in science. Something that should not be the case. It's sad that science was one of the first casualties of the pandemic.
well, artists are a bit different.
When they die, they can no longer produce more pieces, so the price starts to go up.
@@1pcfred he would have been financially rewarded properly had he not completely surrendered his rights to electricity royalties from westinghouse
@legg The unit of magnetic field strength is the Tesla.
Great video! I can appreciate the effort that went into producing this. I didn't know a lot of this history, thanks.
Do you like mashed potatoes?
@@glennasaurus81 it's all about the milk when talking mashed potatoes
Not milk. Heavy cream! and about a pound of butter!!
@@mashedpotatoes5323 Yes with plenty of countrylife butter and some full cream milk. 😋 😋 😋
Wow! EEVblog is here too! Love you channel too😁
That was thoroughly fascinating. I remember taking electronic classes in high school and unaware that this would require all the Algebra I learned in middle school. Thanks for putting this up! Marvelous story.
My high school Physics teacher was Ken Ohm and his version of Ohm's Law, given with a huge smile, was "Sit down and shut up!" Thank you for this fascinating story.
I'm so sorry. I had a teacher in college whose mantra was "Read the f___ing book!
Thank you for presenting Ohm's story.
I often fail to appreciate the trials and tribulations of early scientists doing fundamental research.
Asking the right questions, performing the right experiments, and crunching the data into a usable equation.
So many thing can go wrong in the process because there is no path to follow.
and everything without Scopes and digital multimeters
And the materials! My god, it had to be hard to acquire and construct all of that during that time.
Brilliant video. And "Wheatstone bridged the gap...." is especially brilliant!
Thank you, very interesting! I have been an electrical engineer and chairman of an IEEE society but never knew Ohms story until now.
Thank you Kathy for this edifying and scholarly presentation! I have always been fascinated by history of our human quest for truth.
My favorite teachers have been those who explain both science and the human context of its course.
Thanks for the kind words Brian
In germany we call conductivity Siemens (S) but Werner von Siemens wasn’t very well liked in the English-speaking world so they tried to avoid his name by using mhO as the unit
I'm pretty sure in the electronics world, they do use the Siemens. Even if the scientists chose not to. Just like they use j rather than i in complex maths. Lower case i means something else to electronic engineers. Incidental current.
Maybe because because his name sounds like semen.
Originally conductivity was mhos and I remember using it with vacuum tube design in the late 60s/ early 70s. In 1971, the 14th General Conference on Weights and Measures approved the addition of the siemens as a derived unit. The unit Siemens took a while to catch on and I first started seeing it in textbooks in the late 70s. My preference is mhos as the name is self explanatory for the inverse of ohms.
@@AndrewHalliwell I heard both Siemens and Mhos defined for conductivity in the electrical engineering courses I took in college. The way it was described was that Mhos was an antiquated term later replaced by Siemens.
I have a bachelor's degree in electronic engineering . Got it over 50 years ago. They did not cover any of the history that you covered..
I found it very informative. Thanks !
and very formative ... I d have seen EE the way I like to be taught::: from the beginning..
I feel the same. After more than 50 years finally I heard the history behind.
@@billferner6741
They lie & edit everything.
@@greggstrasser5791 a general statement without any details you made. Stop it, please.
@@billferner6741
If you don’t already know, you’re part of the problem. Go get your booster shot.
One of the things I most loved about physics class in middle school was how my teacher re-created the environment in which these major discoveries were made. The fascination of the up-to-then unknown. The extremely limited resources and tools they had to use, and how they used each others results and discoveries to make their own.
You have that same gift of bringing it back, and added the political shenanigans that made or broke scientists.
I am teacher in the electrical field and have studied the field all of my life and to date still active in the electrical industry. I for one think you and your team have done a marvelous piece of work as well as the many other presentations I have seen you produced. Your research, presentation, expression is most enlightening. Super terrific job !!!
Thank you. I would thank my team but I have no team (aside from a friend who sings the intro song).
you are truly amazing !! thank you so much for all of your videos
@@b.m.2392 hey... we're all in the field... the electromagnetic field... I'll show myself out.
Wonderful dissertation on ohm. Used his formula all my working life but never knew how it was derived, I just took it for granted. Now that I know the story it makes the discovery much more profound.
I’ve been shocked at how many times looking into the history of something I felt like I understand inside and out made me understand it in a deeper way. Glad you feel the same way.
But it currently has power.
@@1SnuffySmith Lmao, please there's the door!
I know, I know...even I'm cringing at what I typed.
One thing lost in this entire narrative is the battle going on between engineering and scientists. Georg Ohm being a commoner AND a practical engineer was not given the same respect as some scientists. His ideas would be summarily dismissed by the wealthy and independent scientists.
Interesting. Maybe, she'll cover that next. I always love hearing about the ways human behavior is so similar to petty fights that occur today.
Seems to be the case throughout history and is even common today. I'm not surprised it took interventions of engineers and soldiers making surprising new inventions that worked to finally sway the scientific community. One the sayings goes, "Scientists spend most of their time trying to prove things impossible. Engineers make the impossible work.
Hedy Lamar is another scientist that may not have gotten the traction she deserved if it wasn't for the US Army and US Navy being heavily interested in her works on radio signals that led to Frequency Hopping Spread Spectrum. That technology makes modern day communications possible. And due to her being a film actress, 'pretty face', and self taught would have likely been dismissed otherwise.
Ohm was a PhD of Mathematics by education and not an engineer. After his PhD he worked as a lecturer of maths and physics at university for 3 semesters and then became a teacher of maths and physics
@@taemien9219 What Lamar did was tinkering and inventing, or "engineering", rather than "science". Since you are talking about this distinction and how the former "guild" could sway the latter to take new discoveries seriously, the example of Hedy Lamar's technical inventions really does not fit here. There was no new physics she discovered, no new theories the scientific community had to be convinced of through her inventions. The FHSS concept she and her co-inventor developed is "just" a very practical technique which is now in use everywhere in wireless communications.
And from what I read I don't get the impression that she gained a lot of traction for this short "side-hustle" as an inventor until near the end of her life. The Navy's interest in her work was rather passive. Lamar and Antheil presented it to them to assist in the war effort. But they couldn't quickly put it to practical use during WWII anymore. The Navy then only picked it up 20 years later when the patent had expired, which then established its use for later applications. Two or three years before her death she and her co-inventor for their frequency hopping technique received a prize for their work and were honoured for it, since it was to be used now in Wifi and Bluetooth etc.
Lamar and Antheil's concept and later developments based on it are very useful and put to good use today, sure. But to say that it "makes modern day communications possible" is a huge hyperbole, I think. It's not an overly sophisticated concept, no truly groundbreaking discovery, but just one quite robust and practical technique among potentially many similar ones. And work on related concepts was also done by others. To assume no one else would have come up with a comparably useful solution to the problems it solves by the time there was explicit demand for it seems unlikely.
TL;DR - Honour where honour is due and all, but Hedy Lamar received most recognition for her pretty face.
@@epajarjestys9981 In the public maybe. But the honor is given to her in classes within Army Satcom. Especially in subjects you won't see in civilian college institutions.
Given I'm an Electrician & Electrical Engineer, I love your videos, as I'm a big believer in non rope learning, you filled in many boxes for me after 30+ years. My eldest son's studying Elect Eng now, Ill also be showing him your videos. Thank you for your effort.
It's a little mind boggling to realize that basic laws of physics were controversial when they were first discovered (discovered, not written!) Something like Ohm's law would have eventually been found to be true regardless of what the royalty of the scientific community said, but the soap-opera-like behavior of some scientists makes you wonder how they managed to achieve their positions in the scientific world.
That's why I don't understand why some people believe that scientists are some special type of people, who seek truth only. We are all humans and are affected by greed, lust for glory. And we should not exclude politic's influence on science. That's why some people don't trust some "science backed" claims related to climate change and coronavirus.
Ohm's law is not a basic law of physics. It applies to some materials at some range, but it is not like maxwells equations which are a basic law of science.
True, but they were limited by their knowledge and own experimental equipment as demonstrated with the batteries.
Part of challenging the status quo depends on a belief in yourself, regardless of what the everyone else believes.
Once demonstrated and explained properly, I'm sure most would agree, though those who disagree might further their own experiments until they came to the same conclusions, (or discovered something new!).
@@andik70 I don't think Ohm was fully aware of what he had just discovered. I am an electrician and electrical engineer, and I couldn't believe how some scientist could doubt Ohm's law. Kathie showed me where the source of the problem was.
They measured the magnetic forces without knowing exactly what the origin of these forces was, they only knew that they were related to electricity. For this reason, they might have admitted the idea that the electric current might not depend on the "voltage of the source" at all.
I was convinced that it was obvious to the early electricity researchers that voltage caused current to flow, and Ohm's discovery was that the relationship between voltage and current was approximately linear ... and I was wrong. They may have been convinced that the "source" was the source of the electric current. They didn't have the instruments to measure it as accurately as we do today, they didn't know that their "electricity sources" had "internal resistance". Today we know Thevenin and Northon's theorems about substitude voltage sources and current sources. They had no idea about it then.
It should be remembered that then the electric current was measured by measuring the force deflecting the magnet in the field generated by the flowing current (today we call such an instrument magnetoelectric) but there were no voltmeters. The first voltmeters used the ohm law to convert the value of the current flowing through the ammeter into voltage. It was not possible to discover Ohm's law by using a voltmeter constructed according to Ohm's law.
So I think Ohm's fundamental discovery is that the electric current is an EFFECT of the voltage, and its value depends on the physical parameters of the circuit.
@@warvariuc you should apply the same standard to any conclusion not only the ones you prefer for whatever reason. Because it is always more reasonable to abide by a generally scientifically backed consensus than any other notion. Especially if one can’t really understand the subject. To me the important part is always to know when my posture is based on stubborn refusal to admit wrongness no matter how reasonable was at the time with the data available.
btw. Great Work: the Internal Resistance of the battery, and batteries in series adding more total resistance , which sent them making wrong conclusions - versus OHMs thermocouple power supply - is a great insight ! Thank you for all these amazing details
Thanks. I always find it frustrating when biographies say “people believed x but famous scientist did not” without telling why.
I'm very sad that Ohm was dissed nearly up to day.
I'm living in Cologne all my live. In the late 60th our school ( ... the teachers) discussed to name the school formerly only known as "Realschule für Jungen Ehrenfeld". BUT - (during that time everybody who was a teacher got a job) we had many teachers for German ( .. and history or geography) but only one teacher for science (he was the only to teach biology, physics and chemistry).
This teacher first thought of "Siemens" school - he hoped of some sponsorship we could really use. Then his strong whish was "Georg Simon Ohm Schule" - most of the pupils loved. He argumented that he was a teacher in Cologne, that no school was named after him before and due to Ohm's law it would be really honoable.
But he was driven down by all that ugly German teachers - the school became "Eichendorff Realschule".
I hate this up to day.
Well... at least they didn’t name it after a BS artist like Einstein.
Well, Cologne eventually got its "Georg-Simon-Ohm-Schule" in 1982. So that's a bit of a happy ending.
Why do you disrespect Einstein, @@greggstrasser5791?
@@KenJackson_US he’s saying it “tongue-in-cheek.” After all, if the academy is going to disregard a pioneer in the field like Ohm, may as well go all in and disregard another pioneer…
@@KenJackson_US He was just a HUGE fraud, dude.
Thank you for this video. I am a diagnostic technician in the automotive industry and teach at a local vocational college. Intimately familiar with Ohm's law and never have heard the history of Ohm and his discoveries covered elsewhere. I think this will be useful for teaching electricity to students in the future as what is in the textbooks we use always start with "this is an atom... here are the shells... blah blah blah..." and you've lost them. This is way more interesting than the part that has nothing to do with how it was discovered or how they will use that information to test electrical circuits. I've found over the years that there is a huge deficit in the average mechanic/technician on how to test circuits using voltage drops and that my students excel in the 'real world' because we pound that in until it is second nature. I want my students to be able to calculate everything in a series/parallel circuit and know WHY it works. Thanks again.
Working in my industry where we take all the this for granted, it's so great to know the history of the people who did all the ground work from scratch. Thank you so much for you videos 🙂
Thanks
@13:10, you make a sly reference to Wheatstone ("...who bridged the gap..) which you later detail at 15:15. That was priceless.
Just a bit of background about Ada Lovelace. She was the daughter of Lord Byron. She was a math genius in her own right, didn't care for nor respect her poet father. The symbol for the cryptocurrency, Cardano, is ADA. And 0.000001 ADA is a Lovelace. Today, ADA is quoted many times every day, and her father not as much anymore.
Wow ....
I never thought that ohms law had to face huge resistance:)
So many good puns… so little time
13:10 “..there was an engineer named Charles Wheatstone who bridged the gap..”
I love hearing about the original experiments used to come up with these formulas, or details like that they thought of voltage as "tension".
I find that a decent understanding of the history of a formula makes it far easier to understand. Today they're often just thrown at us with too little context, making them appear arbitrary or magical, when they're actually easy to understand when you see the original measuring setup in its historical context.
Great presentation. Ohm's law was one of the many laws I had to memorize in high school radio shop class. I did have a teacher like Kathy in high school in the '50s. He was a retired RCA engineer that made electronics fun.
When I was young, and learned Ohm's law, I learned the reciprocal unit (conductance) as the mho, however nowadays a mho is called a siemens.
Sorry to be a pedant Timothy, but “cycle per SECOND” is now known as hertz 😉
@@timothystockman7533 Sorry to be pedantic again (!) Timothy, but one could never say that the ACTUAL UNIT itself is IRRELEVANT notwithstanding the fact that in everyday engineering parlance, it was abbreviated to “cycles” for convenience. It was NOT cycles/minute or cycles/hour, but cycles/second, so yes, it is entirely relevant.
Just as, for example a 27k resistor or a 10u capacitor are both abbreviated, the actual units are still “ohms” and “farads”.
Your original point was that the old term for conductance, “mho” is now “Siemens”, which is of course absolutely correct.
I was stressing that, strictly speaking, “cycles per second” is now Hertz, not “cycles”, regardless of how it was abbreviated amongst electronic engineers and technicians.
The deeper you get down the rabbit hole, the more interesting it get's. When I learned that stuff in the 1980s we uses siemens, never heard of mho before.
And now I just found out that there was even an unit of resistance called "Siemens mercury unit" that was defined in 1860, which was then superseded by ohm (Ω) in 1881. And it seems that even publications that name the unit siemens sometimes use ℧ as the symbol when there could be mix-ups because of the letter S.
Thanks not correct. Conductance is the inverse of resitance. Suspentance is the inverse of Reactance and Admittance is the inverse of impedence which is the Mho that is now called Siemens.
@@jeffreydove2036 Of course, you mean Susceptance not Suspentance ....
Thank you for this excellent video. For many of us that work in the electrical world, we take things like Ohm's Law as fact and think well that's relatively easy, straight forward and obvious. Did not know how much work and troubles that one person had to go through to get his ideas accepted. That must have been so disheartening to Mr. Ohm to know he was correct, yet the scientific community at the time did not accept his work. Glad that Mr. Ohm got to see is work accepted and recognized as time progressed.
I am a retired electronics engineer. I find your stories fantastic as I only learnt the theory but not the history so is very enlightening. Looking forward to more.
This is great. I've been a EE for 30+years. My interests are science and history. When they are combined....
Keep it up I'm now a subscriber.
Thanks Kathy for presenting such an interesting and entertaining account of the history of Ohm and his discoveries! It's fascinating to see how such a fundamental and frequently referenced law was at one point in time considered completely wrong by the scientific community. I honestly felt a wash a relief knowing that Ohm was vindicated during his lifetime and was able to regain a bit of his self confidence and pride as a pioneering scientist. So much of what we know today is built upon the shoulders of others who overcame many challenges to discover something remarkable. Thanks for all your hard work!!
I was also very happy that he was honored in his lifetime after all his struggles. Cheers Kathy
Kathy, thanks so much for this. Ohm, Wheatstone and the countess Ada Lovelace! That last one had me crying with joy! What an amazing tale that all EE's should know.
My study of electricity and electronics started in 1975. Today in 2022 my memory is pitiful, but I still remember the excitement I felt on learning Ohm's Law. It helped so many things make sense.
Enjoyed this video, thanks. Only wish we'd have heard if - was it Pohl? - ever ate crow for having caused Georg Ohm so much grief.
Just discovered your content today and have binging on it for hours. This is GOOD STUFF!
As a fellow fan of history and the history of technology, I thought I already knew a lot about these topics, but was delighted to be further educated. Thank you.
Another great presentation, and a bit of important history I never learned in engineering school. Thanks Kathy!
I realize belatedly that Ohm's first name is pronounced wrong in this video Georg is not George! Sorry about that.
It’s better than the way you pronounced Marconi’s first name😂, great vid, keep em coming, yes to Wheatstone 👍
I understand it might be too much work, but I guess I talk for must of us. Thank you for your replies. 🌹
@@theklaus7436 you are welcome. I like replying to nice people
While we are on the subject, Rutherford is pronounced ru-their-furd 😀
@Science Revolution, really, dude? Have you made this observation from space? You realize that the ocean is made of water -- right? And that it doesn't have to maintain the same level everywhere, depending on the force(s) acting on it -- right?
Have you measured the thermal cycling of the landmass? If you do, you'll find that your idea on the matter are nonsense.
But hey, in these post-modern times, whatever you want to believe is your personal truth, so hey, gratify yourself.
How you put together the history of stuff I pretend to know gives me so much insight. It's difficult for me to listen to all of your back catelog in a row because I get lost in it while I'm trying to work. The social relationships and chronology of discovery has really deepened my understanding and I can't thank you enough.
Thank you!
Really nicely done, Kathy! I'm a physicist as well and always enjoy your videos. I love what you bring together: you bring a lot of perspective and tell a story well.
Ohm's law is probably the simplest and more intuitive of all of electromagnetic theory. It is almost unbeleivable from our point of view that if could had so much opposition back in the time. But, as always, you are able to present the facts in their historical context. They didn't even know that batteries had internal resistance, no wonder nobody could come up with Ohm's law before Ohm, who was the first to make controlled and precise measurements, even resorting to Seebeck effect in place of batteries as a steadier source of electricity. Brilliant video, thank you!
A book that describes the opposition to new ideas is The Structure of Scientific Revolutions by Thomas Kuhn.
@@c_b5060 Kindle is wonderful
Another book is The Cosmic Serpent.
I like how you stated that Wheatstone "bridged the gap". Brilliant!!! Also, Mhos was never adopted as an official unit for conductivity. The official SI unit is Seimens (S) named after Ernst Werner Siemens.
Your channel represents something I have always wanted but didn't knew it. Thank you!
Kathy, thank you for sharing your passionate love for physics and electricity with us! While I didn't study anything in the hard sciences, I've always enjoyed learning about them, and your joy for the subjects you cover is absolutely infectious! Your videos always brighten my day, and I want you to know that :D
What an interesting video. I'm a physics teacher and teach the subject without really knowing the history of much of it. Watching this made me want to know more of the historical background, the development and the people involved.
Those laws are the Zenith of European science: Ampère was French, Volta Italian, Watt British and Ohm german...
Got this video randomly recommended. Super interesting topic, and very well presented. I was completely drawn into your lecture.
This channel is one of my favorite new finds on CZcams. Dinner-time stories just got more interesting :)
This was extremely interesting. It's just so easy to ignore how messy was the genesis of the subsequently distilled theories we read about in textbooks.
Also, how long it took to get agreement across nations!
I recently watched a valuation of an restored antique Ohmeter on a TV show (Bares für Rares) where the expert could date the model to 1898, as the omega symbol on the dial was first officialised in Germany that year, 40 years after your date for Britain. it was a beautiful hardwood box, but more in your tinkerer's category. It used the earth's magnetic field as a constant source. That meant it needed to be aligned in the magnetic field to calibrate the readout.
Thiis is anecdotal, the expert could have been wrong, the dials added later during restoration, for example. But decades to cross the North Sea and further decades for the symbol to return are a long time, in any event.
I have a masters of science in electrical engineering, and designing circuits for 40 years, and I have never heard this story. Hard to believe they gave him so much grief. Great job!
George Boole’s work was tossed out as well as it had no practical use even if it could be proven to be true.
Great video, your enthusiasm for the subject is infectious!
I work as an Electronic Engineer for a company that services X-Ray , Ion Mobility, and Mass Spec products. Ohm's Law is the core of everything I do every single day. Voltage is current x resistance is a formula I use every day just like how our lungs pump oxygen into our blood. Thank you for this video. I had no idea he went through this. I now have even more respect
Great stuff! Seems so simple today, but it wasn't in the day. I love all the images you found to illustrate this video.
Thanks
Ohm my goodness! You put a lot of work into researching this. Well Done!
What a video. You have done a marvelous job. Linking so many dots from the history
Thanks so much for your series Kathy. Brilliantly explained and throughly entertaining. As a physics student one hears all these names and uses their ideas but I've never their development as being so intertwined and connected. It really creates a deep appreciation of just how physics/science evolves and ideas change from their intial forms into the equations and formulae that we use today. Excellent - thank you.
I read somewhere about Ohm's biography and how he was been 'ridiculed' due his mathematics ( as maybe, he simply wanted to show off), unknowingly that a simple relation of E = IR (or V=IR) is good enough to prove that his discovery made the world of Electronics ( on both Analog and Digital versions) an amazing phenomenon of the modern time. Great video. I love it!
Very interesting you have rekindled a once almost obsessive interest in the invention of electricity and the scientists involved. Looking forward to watching more from your excellent channel.
this is awesome thank you for taking the time to do this ,,
OK, this is the most underrated CZcams channel.... love it!!!
Another great video. I find it amusing that Kathy speaks about tension with quotation marks, as in my native language, we literally use the word tension when we spak about voltage. In German they use the word Spannung (tension) as well. Also, I hope Kathy will eventually make a video about Ada Lovelace (and Babbage). Another interesting person to cover would be Margaret Hamilton and her work at NASA.
In the US voltage is rarely called tension except in one case: The tall long-distance electric transmission lines, running at hundreds of kilovolts, are commonly called "high tension lines." I'm quite sure that people do not realize they are using a synonym for voltage, because after questioning a random sample (a handful) of people, most thought they were called that because the the wires were tightly stretched.
In Spanish you can find books that prefer "tension" (tensión) or "voltage" (voltage). Older books tend to use the former. Newer books mostly stick to voltage as they most of the time are translations of books in English, but do make a mention that "tension" is also a valid term.
Fascinating! Thank you for sharing your knowledge.
Love it. VERY easy to understand your explanations. Thank you.
I stepped into a goldmine. I love physics history, and you my good ma'am have earned a subscriber.
I love these kinds of videos. Modern science is complicated. By loolking at the past it makes it easier to understand. Its also amazing how much these scientist were able to discover with the equipment they had. I do not think basic measurements such as the metre were standardised by than as well. great work. keep it up. one thing that would be great is to give the terminology these scientist used and what they meant by those terminology and how we understand these terminology now.
Your videos are so beautifully detailed, thank you for your careful and in depth research.
Thank you for sharing this delightful and inspiring story.
It is so horrible that a brilliant man like Mr. Ohm whose work is literally used constantly all over the world was not able to prosper by his work! Everyone who works with electricity in any capacity owes George Ohm a serious debt; alas all we can do is remember his contribution and celebrate his legacy.
Great Video, I learned a lot!
Some fun facts:
The german word for voltage is "Spannung" which directly translates to tension, so here we still call voltage tension.
Also at least in Germany the unit for conductivity is "Siemens" and not mho.
Siemens is more commonly used outside Germany as well, at least in the Western world.
So happy to have stumbled on this channel. I majored in EE because I needed an engineering major to fulfill my ROTC scholarship. The Wheatstone Bridge was my first breadboard project. I made a digital thermometer using a thermocouple and an op-amp. I graduated in the top half of my class… barely. Keep going, Kathy. 👍
Hey Kathy, stumbled across your video, and I love the way you deliver these documentaries! Subscribed!
Wow, so interesting thank you for putting this together.
So glad you liked it
I am currently recreating the apparatus, used by Ohm to derive his law, for my daughter's PHD. It's been an interesting path trying to decide why some of the features in the diagram (which you only show a small part of) were the way they were. We think some of the design shows the apparatus re-used some parts from previous pieces of apparatus to save costs. Her biggest issue is that using mercury is no longer allowed to be used the way Ohm used it for health and safety reasons.
I assume you substitute the mercury with a Gallium alloy?
I would assume, that Ohm used a mercury alloy, as solid metal touching liquid metal always leads to an exchange, so "over time" the mercury had to become an alloy.
@@sarowie She has already ordered some gallium. What Ohm did was to coat the copper of his apparatus with varnish where it went into the mercury then filed the end of the bars before dipping them in the mercury in small cups (he had the cups on a platform that was raised into position and locked there). This gave a constant area of clean copper when it was immersed in the mercury. This was because there was no industry producing a means of making good connections in electrical circuits and he was trying to reduce the experimental variables as much as possible.
I enjoy your giving the history of electrical knowledge. You have wonderful clear way of conveying information.
Thank you so much for this historical perspective on Ohms Law, Kathy! I studied computer electronics in the early 1980's and I'm retired now. I am also a fan of history and thoroughly enjoyed your video! I look forward to watching more of your videos!! - Tom
That was a really interesting and informative lesson on someone that has made such a massive impact on our modern world. Thanks for that.
Glad you liked it
I have always loved the simplicity of Ohm's law and it is one of the move beloved tattoos I have. It is literally part of me.
No doubt a terrific conversation starter!
OUTSTANDING!! You are a great speaker and foster unusual interest.
Kathy, Thank you very much for your nicely presented video detailing the story surrounding Ohm’s Law. I’ve used Ohm’s Law regularly over a 30 year career and never knew this very interesting story. I also kind of like how you speak with your hands. I look forward to more interesting stories regarding various illuminaries whose work I greatly admire. Ed
Great video - Wheatstone Bridge is at the core of how most modern electronic weight scales work (known as a " strain gauge load cell" in the industry) - so while not at the level of Ohm's laws it has neat modern relevancy.
Great piece of science history. As a retired EE Ohms law pervades all of electronics. I had not realized it initially met with so much skepticism, probably should not have come as a surprise given how early his work was.
I was surprised how much resistance there was too, if you don’t mind the pun.
@@Kathy_Loves_Physics Fortunately, Ohm conducted himself professionally at all times, and eventually scientists came around to his way of thinking. 😉
I love what you did at ~13:10 when you talked about Wheatstone "bridging" the gap between the tinkers and scientists.
As soon as you said that, I chuckled and said, "That was nice!"
I enjoyed this. Thank you. I'm an electrical engineer by profession, and it was fun to think about how people might have thought electricity worked before it was well understood.
Taking electrician classes at night and the first thing the teacher covered was Ohms law. Fascinating stuff from a brilliant mind.
Another excellent presentation. However, let me point out that in today's world, the old unit of conductance (Mho) has been replaced by Siemens, symbol upper case "S."
I'd like to hear about Wheatstone's bridge and it's applications.
Thanks for keeping us current about Ohm! 😊
Outstanding presentation Ma’am. You’ve earned a subscription!
I really like your videos! There is one thing you can improve though: can you put the sources in the description of your videos? Sometimes there are topics and stories I would like to know more about, and not always I can find good sources.
Good Idea!
@@Kathy_Loves_Physics I see you did that already, that's amazing! Thank you so much!!
@@lorenzobarbano8022 of course, thanks for reminding me
Yes, "mho" appears in some texts, mostly in older American ones. To my knowledge the International System of units uses Siemens instead for the conductivity.
Just found your channel and this video was super interesting! Awesome job and keep up the amazing work.
Such a simple and beautiful equation....! Thanks for your great work Kathy.