Shocking

Great pun!

I guess the established scientist’s weren’t all to amped up about the new theory

Ohm my!

So much tension !

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?

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.....

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! 🙂

Wow legends

72 years you say, so you must have heard of William Shockley

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 :-)

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.

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.😉😊

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

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😁

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.

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.

Thanks for the kind words Brian

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.

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.

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.

I'm so sorry. I had a teacher in college whose mantra was "Read the f___ing book!

Thanks. I always find it frustrating when biographies say “people believed x but famous scientist did not” without telling why.

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.

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 was also very happy that he was honored in his lifetime after all his struggles. Cheers Kathy

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.

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 ....

So many good puns… so little time

13:10 “..there was an engineer named Charles Wheatstone who bridged the gap..”

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.

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.

Thanks

George Boole’s work was tossed out as well as it had no practical use even if it could be proven to be true.

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.

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.

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.

Glad you liked it

Siemens is more commonly used outside Germany as well, at least in the Western world.

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.

So glad you liked it

Thank you

No doubt a terrific conversation starter!

Glad you enjoyed it!

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

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. 😉

Obviously I love physics history too.