Unveiling the electron with oil drops

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  • Опубліковано 15 кві 2024
  • Support the channel: ko-fi.com/jkzero
    Detailed presentation of the historic oil-drop experiment conducted by Robert Millikan and Harvey Fletcher, which determined the electric charge of the electron and established the electron as the first subatomic particle.
    Videos:
    The Birth of Quantum Mechanics • The Birth of Quantum M...
    Millikan tests Einstein's Light Theory • Millikan tests Einstei...
    Playlist: Quantum Mechanics • Quantum Mechanics
    References:
    ∘ J.J. Thomson, Cathode Rays, Phil. Mag. 44, 293 (1897) books.google.de/books?id=orp_...
    ∘ R.A. Millikan, The Isolation of an Ion, a Measurement of Its Charge, and the Correction of Stokes's Law, Phys. Rev. 32, 349 (1911) journals.aps.org/pri/abstract...
    ∘ R.A. Millikan, On the Elementary Electrical Charge and the Avogadro Constant, Phys. Rev. 2, 109 (1913) journals.aps.org/pr/abstract/...
    ∘ H. Fletcher, My work with Millikan on the oil‐drop experiment, Physics Today 35 (6), 43 (1982) doi.org/10.1063/1.2915126
    Credits:
    J. J. Thomson with his cathode-ray tube by pixel17.com under CC BY-SA 2.0 Deed creativecommons.org/licenses/...
    Crookes tube by D-Kuru under CC BY-SA 3.0 AT Deed creativecommons.org/licenses/...
    Cathode rays deflected in a magnetic field by M. Białek under CC BY-SA 4.0 Deed creativecommons.org/licenses/...
    Robert Millikan, public domain
    Albert Michelson, public domain
    Michelson interferometer, public domain
    Ryerson Physical Lab at UChicago, public domain
    Erich Regener by Regener family under CC BY 3.0 Deed creativecommons.org/licenses/...
    Wilson cloud chamber by Caltech, The Mechanical Universe • Episode 12: The Millik...
    Harvey Fletcher, public domain
    Magic Lantern by A. Niemimäki under CC BY-SA 2.0 Deed creativecommons.org/licenses/...
    Pocket watch by F. van Duns under CC BY-SA 4.0 Deed creativecommons.org/licenses/...
    Vintage atomizer perfume by A. Andriot & Vetiver Aromatics (vetiveraromatics.com) under CC BY-SA 3.0 Deed creativecommons.org/licenses/...
    Mist spray by K. Grabowska in Pexels www.pexels.com/video/a-person...
    Harvey Fletcher, public domain
    Oil-drop apparatus, public domain
    Fletcher-Millikan's setup for the oil drop experiment, public domain
    Bell Telephone Laboratories, Murray Hill NJ, public domain
    Harvey Fletcher by Karden-Kazanjian, Bell Telephone Laboratories Publication Department, courtesy AIP Emilio Segrè Visual Archives
    Fletcher conducts a hearing test on school children (1928), Bell Laboratories / Alcatel-Lucent USA Inc., courtesy AIP Emilio Segrè Visual Archives, Lillian Hoddeson Collection
    Technical Grammy adapted from A. Blumlein under CC BY-SA 4.0 Deed
  • Наука та технологія

КОМЕНТАРІ • 162

  • @felipemonteiro5877
    @felipemonteiro5877 28 днів тому +70

    Most channels spew out the theory and try to make the math palatable, however they always skim over the most important part: the experiments. Science is fundamentally about understanding the natural world through observation, experimentation, and analysis. Sincerely, thank you for looking at it more carefully. It's how we ask nature questions!

    • @jkzero
      @jkzero  27 днів тому +16

      I find most accounts of these stories to focus on the final result but I find the problems, the struggles, and the wild guesses fascinating and decided to share them here. Glad to find so many people moved by these stories and that don't shy away from some taste of the math behind.

    • @shimrrashai-rc8fq
      @shimrrashai-rc8fq 25 днів тому +2

      Also, what is more exciting and memorable? Some obscure "F = qv x B" stuff, or to actually SEE what that means in front of your very eyes?! Note also that human memory works on emotional valence and association: you are much more likely to remember those more mathematical concepts if you can actually interact with them in some tangible way.

    • @hedgehog3180
      @hedgehog3180 22 дні тому +2

      The experiments are also often the most difficult part epistemologically since that's where you try to figure out what exactly your hypothesis means in reality and how you can translate the real world into math and what exactly you can figure out from this experiment. I think the brilliance involved in designing experiments is similar to the feeling you get when you solve a really hard puzzle because you often need to really think outside the box.

  • @clarencegreen3071
    @clarencegreen3071 27 днів тому +18

    As an undergraduate assigned to "work" in the physics department as a dust-rag boy and gopher, I was fortunate to do the oil drop experiment at my leisure. I spent hours watching the tiny points of light move up and down, and sometimes suddenly change the rate at which they moved. With one droplet, I calculated the change in charge to be that of one electron. One electron, I say.
    This was at East Tennessee State University in the early 60s. I'm forever grateful to the faculty for allowing me the opportunity to use the equipment as I chose. They were Marvin H. Dickerson, John C. Whitson, and Austin Graybeal. Mr. Graybeal was like a grandfather to me, and I shall never forget him. Thank you, Sir!

    • @jkzero
      @jkzero  26 днів тому +1

      Thanks for sharing your experience, I was also lucky enough during my high-school years to get access to a fantastically well equipped physics lab and spent long hours reproducing experiments from a textbook, some of the most active years of learning by doing. Good times.

  • @ngudududlamini252
    @ngudududlamini252 29 днів тому +38

    This is my new favorite channel

    • @jkzero
      @jkzero  28 днів тому +6

      All right! Thanks for that and welcome to the channel! I am always curious to know what brings viewers to the channel, were you searching for something in particular or did the 'mighty algorithm' find you?

    • @ngudududlamini252
      @ngudududlamini252 28 днів тому +6

      @@jkzero I liked and followed you after i was recommended that video about a plane avoiding a nuclear blast wave.ever since then I've never missed a single video . Bro,I like your content I'll be supporting you If I had any means but I'm just a broke dude from south african township. But I'll support you by liking and commenting. I love science content 👌

    • @jkzero
      @jkzero  27 днів тому +5

      @@ngudududlamini252 thanks for sharing how you got here; and thanks for supporting the channel in other ways, your comments, likes, and sharing in other platforms is a great way to bring more traffic, no need to support financially, that is only for those who can. I appreciate the loyalty and I am glad you find the content of value.

    • @chillphil967
      @chillphil967 27 днів тому +3

      saying hello as well from detroit, Michigan! love the channel great content, watch every video :)

    • @jkzero
      @jkzero  27 днів тому +4

      @@chillphil967 greetings to the Motor City, thanks for watching

  • @CaptainCalculus
    @CaptainCalculus 28 днів тому +16

    One of my favourite experiments: right up there with the Cavendish experiment for fiendishness

    • @jkzero
      @jkzero  27 днів тому +2

      Dear Captain Calculus, tip of the hat for your continuous support. I had to search the meaning of the fiendishness. Academia is fertile soil for this kind of personalities.

  • @hsenagrahdeers5468
    @hsenagrahdeers5468 17 днів тому +2

    Why did it take me SO LONG to find this channel! Dr. Diaz, you are 3b1b of physics! Thanks for existing!

    • @jkzero
      @jkzero  10 днів тому

      Hi, I am glad you made it here. Thanks for the compliment, it means a lot. I am always curious to know what brings viewers to the channel, were you searching for something in particular or did the 'mighty algorithm' find you?

  • @AwkwardDemon
    @AwkwardDemon 24 дні тому +7

    The balance you maintain between theory, history, and narrative while going through these topics is seriously impressive, and I very much like your emphasis on the achievements and contributions of the greats who've been more-or-less overlooked by modern texts (like Fletcher).
    I'm looking forward to see what comes next!

    • @jkzero
      @jkzero  23 дні тому

      Thanks for your kind feedback. When I was a physics student I learned the solutions to the problems of the time but I remember that the lack of context and details was quite unsatisfactory. Now that I have time, I decided to dig deeper, read parts of the original papers, and I decided to share the details and found that the stories get even more fascinating. Millikan, round 2 is coming soon.

  • @nikospitr
    @nikospitr 29 днів тому +18

    love these vids.
    Thank you, it s something completely different and much more original and interesting than the usual "happy smile" pop science we are bombarded with, here at the internet.

    • @jkzero
      @jkzero  28 днів тому +4

      Glad you enjoy it! I am totally with you. When I was a physics student I learned the solutions to the problems of the time but I remember that the lack of context and details was quite unsatisfactory. I decided to dig deeper, read parts of the original papers, and I decided to share the details and found that the stories get even more fascinating.

  • @horacioguillermobrizuela4295
    @horacioguillermobrizuela4295 27 днів тому +15

    ¡Thank you so much! From now on I´ll refer to this experiment as "the Fletcher-Millikan Experiment"

    • @jkzero
      @jkzero  26 днів тому +3

      I think that is appropriate, it is true that the brain behind the design of this clever experiment was Millikan but the execution and hard work was Fletcher, he deserves his share of the credit and I thought it was important to highlight these stories because in the end all great scientists in our textbooks were human, and as such some of the best and the worst side of human nature shows up. I want to show the human side of things too so people understand that in academia there are situations like this.

    • @hedgehog3180
      @hedgehog3180 22 дні тому

      @@jkzero Recently in my country there was a scandal about professors being credited as authors on papers that were really completely the work of their students where the professors didn't really do anything other than offer assistance.

  • @shimrrashai-rc8fq
    @shimrrashai-rc8fq 25 днів тому +1

    I remember I saw this demonstrated for me in one of the physics courses I took at my first college. My mouth must have been hanging as I realized that electrons - these things you only usually read about - here they were, playing right in front of my eyes!

    • @jkzero
      @jkzero  25 днів тому +1

      Seeing those droplets go up and down is a very special moment, then reversing their motion by switching the polarity of the plates confirms that really they are suspended and moved by the electric field. This is really a fantastic experiment, a historic result, and a mind-blowing demo for students.

  • @erenerdem4657
    @erenerdem4657 29 днів тому +4

    Thanks for the series on concepts like that( especially quantum physics and calculus ideas underlying it). I want to find whether someone will found my quantum things before I announce them.

  • @santiospina4504
    @santiospina4504 28 днів тому +3

    I discovered your channel a couple hours ago and I'm simply in love. The historical details makes physics a lot more interesting.

    • @jkzero
      @jkzero  27 днів тому

      Thanks for watching and the positive feedback, make sure to check the other videos and welcome to the channel. I am always curious to know what brings viewers to the channel, were you searching for something in particular or did the 'mighty algorithm' find you?

  • @gametimewitharyan6665
    @gametimewitharyan6665 29 днів тому +3

    I have to read about this topic in the next chapter and I wanted to know about the details of the Milikan's experiments
    The video is a gold as always 🎉

    • @jkzero
      @jkzero  28 днів тому +1

      Great timing, I am glad you liked the video. It ended in a cliffhanger; follow up coming soon.

  • @ihmejakki2731
    @ihmejakki2731 28 днів тому +2

    Love the little trivia on old notation practices!

    • @jkzero
      @jkzero  27 днів тому +3

      you call it little trivial, I call it rant :D One things we always tell students is don't forget the units, and most of these old and historic papers show values with no units! I might have also included that rant because it tool me hours to confirm the units for Thomson's result.

    • @hedgehog3180
      @hedgehog3180 22 дні тому +1

      @@jkzero I had to use a physics textbook from the 80s recently and the author just skipped like half the steps in the derrivation of the Carnot efficiency without even making it clear. It was kinda maddening to try to reconstruct the derivation in a p,V diagram from scratch, but I assume he did this because most of the math needed for it wasn't part of high school curricula back then because of the lack of computers and CAS programs.

  • @sphakamisozondi
    @sphakamisozondi 28 днів тому +1

    Your channel needs to blow up. Your content and how you present it, is very interesting

    • @jkzero
      @jkzero  27 днів тому +1

      Thanks for the compliment, I hope to reach more people. For now I am happy with the appreciation of audience for the work and content. More coming soon.

  • @rayoflight62
    @rayoflight62 21 день тому +1

    Thank you for the Science, and the history of it.
    Greetings,
    Anthony

    • @jkzero
      @jkzero  21 день тому

      I am glad you liked the content, make sure to watch the other videos in this series, plenty of science, history, math, and drama. Thanks for watching!

  • @cewkins721
    @cewkins721 28 днів тому

    Great video! This is the first time i see an in depth explanation of this iconic experiment

    • @jkzero
      @jkzero  27 днів тому +1

      Glad you liked it! Making this video with this level of detail has been on my list since the beginning. I find it fascinating, simple, and insanely precise. Millikan was a jerk but his experiments were beautiful and made history. Millikan round 2 coming soon.

  • @kwastek
    @kwastek 27 днів тому +2

    I remember Millikan experiment from the lab when I studied physics. I love that you are able to see such fundamental things by doing experiments with your own hands.

    • @jkzero
      @jkzero  26 днів тому

      I love this period of physics history when tabletop experiments lead to such fundamental discoveries using cleverly designed experiments. For Millikan's case, all he used was Newton's second law and Stokes' law. Brilliant. New video coming soon: Millikan, round 2

    • @shimrrashai-rc8fq
      @shimrrashai-rc8fq 25 днів тому

      It would be very interesting to determine just how much science you can actually verify empirically on your own at different price points.

    • @hedgehog3180
      @hedgehog3180 22 дні тому

      @@shimrrashai-rc8fq You can calculate the charge of the electron using a handful of LEDs of various colors and a variable power supply which would be a lot cheaper than this experiment. We did that in our class and got a result of something like 1.7E-19 C so for such a simple experiment it works pretty well.

  • @fightingforcatalonia
    @fightingforcatalonia 29 днів тому +6

    eres el padre. Acuerdate de mi cuando seas un goat de youtube

    • @jkzero
      @jkzero  29 днів тому +5

      gracias; todos tus commentarios están publicados acá así que hay referencia para el futuro

  • @artemgorodilov2696
    @artemgorodilov2696 28 днів тому +3

    Just two weeks ago, did that experiment on physical laboratory course xDD.
    Nowadays, we're using cameras for capturing movement of oil drops on video, and then running them through python script, which'll get paths of individual drops by subtracting background from each frame on video and making drops look like a bright dot on a black screen. Then it'll fit them and obtain their velocities. Doing this for couple of voltages, plotting ionization level over charge, linear fit of all the stuff, and you reproduced magnificent 100 years old physics

    • @jkzero
      @jkzero  27 днів тому +1

      Fascinating what we can do today. When I look back at these old but remarkable experiments I can only imagine what they would think of our technology. Do you post your result anywhere public? I would be curious to see the results of the replication of this beautiful experiment.

    • @clarencegreen3071
      @clarencegreen3071 27 днів тому

      I'm impressed with the technology, but I cannot imagine that seeing a video of a falling droplet would evoke the same sense of connectivity as watching a droplet in real time with your own eyes. --Old guy (no smart phone)

    • @jkzero
      @jkzero  27 днів тому +1

      @@clarencegreen3071 glad to have you in the channel; I agree with you, same happens in astronomy, I see mind-blowing images from CCD cameras but navigating the dark sky through an eyepiece is another experience.

    • @artemgorodilov2696
      @artemgorodilov2696 26 днів тому

      @@clarencegreen3071 Sure, but I think you're still experiencing that kind of experiment vibe when you're doing it. Cuz in my experimental setup, I was looking in the chamber by that camera. The only thing is that camera was recording videos also, and so after it was more about physics and some kind of preciseness of the result. I suppose that giving calculation and analysis of data (in some basic way like getting velocities of an oil drops from video) is good to give to outsource, to think more about physics, rather than desperately trying to measure it by looking at each of thousands of frames and comparing drops positions by your own. (I'm lazy 21st century astrophysics student who consider all of that ML stuff and programming in physics as a main instruments of scientist)

  • @jitenderkumaryadav6513
    @jitenderkumaryadav6513 11 днів тому

    This is such amazing science content doing justice to the maths, the experiment, the sources and binding all of them in a very good storytelling. I love this!!

    • @jkzero
      @jkzero  10 днів тому +1

      I am glad you like the content and thanks for watching. I hope you come back for the follow up with Compton.

  • @abrikos1100
    @abrikos1100 29 днів тому +6

    Thank you for video, historical details are truly interesting

    • @jkzero
      @jkzero  28 днів тому +2

      Glad you like the video and thanks to you for watching. I find most accounts of these stories to focus on the final result but I find the problems, the struggles, and the wild guesses fascinating and decided to share them here. Glad to find so many people moved by these stories and that don't shy away from some taste of the math behind.

  • @Blu3B33r
    @Blu3B33r 28 днів тому

    I didn't know about this experiment before. Thank you for sharing

    • @jkzero
      @jkzero  27 днів тому +1

      glad you liked, thanks for watching

  • @franciscoaguero9028
    @franciscoaguero9028 29 днів тому +1

    Sos de lo mejor que vi jorge. Desde que vi el calculo de la masa critica me enamore del canal. Abrazo amigo!!!

    • @jkzero
      @jkzero  28 днів тому

      Gracias Francisco, se agradece el apoyo a la distancia. La verdad lo paso muy bien creando estos videos y me alegra haber encontrado una audiencia. Se viene pronto la continuación que, comeo menciono al final del video, Millikan no paró aquí. Como alguien diría: ¡esto no para, loco!

  • @karhukivi
    @karhukivi 21 день тому

    What makes this experiment all the more extraordinary is the apparatus was cobbled together from some things lying around like his wife's perfume spray and his son's telescope! There is a replica in the "Palais de la Decouverte" science museum in Paris The guide asked if anyone knew what it was for and nobody answered. Eventually I answered in my poor French and the guide asked me "are you a teacher?" so I replied "no, I'm a rubbish collector". It took them a few seconds to see I was joking!

    • @jkzero
      @jkzero  21 день тому

      "I'm a rubbish collector" that's a good one. Thanks for stopping by and leaving a comment.

  • @Brunoscaramuzzi
    @Brunoscaramuzzi 27 днів тому

    Keep posting that we will keep watching!!

    • @jkzero
      @jkzero  26 днів тому +1

      all right!

  • @zebo-the-fat
    @zebo-the-fat 9 днів тому +1

    Ohh... this brings back memories of physics classes at school (back in the dark ages!)

    • @jkzero
      @jkzero  7 днів тому

      many former researchers have written to me to mentions something similar, apparently these old experiments and stories are not only fascinating but also quite nostalgic

  • @Hans-ChristianSchwartz
    @Hans-ChristianSchwartz 20 днів тому

    The level of detail was awesome. And even better, it was understandable : )

    • @jkzero
      @jkzero  20 днів тому

      Thanks, I am glad you liked the video, make sure to check the others. I am always curious to know what brings viewers to the channel, were you searching for something in particular or did the 'mighty algorithm' find you?

    • @Hans-ChristianSchwartz
      @Hans-ChristianSchwartz 20 днів тому

      @@jkzero Yeah, wish I could say something profound, but the algorithm suggested you.

    • @jkzero
      @jkzero  18 днів тому

      @@Hans-ChristianSchwartz Thanks for sharing and I am glad the algorithm is working, I hope you find the other videos of interest too and welcome to the channel.

  • @johnned4848
    @johnned4848 28 днів тому

    Another great episode. Clear precise and fascinating. My only complaint is that I have to wait so long for the next one.

    • @jkzero
      @jkzero  27 днів тому +1

      I appreciate the compliment. I get the fun experience of releasing a video and I can start working on the next, the research, the writing, it is a great experience. Next one already in production, Millikan comes for round 2

  • @t850
    @t850 29 днів тому +5

    ...in the end ego prevailed. Sad and unfortunately not so rare, but fortunately truth wasn't lost to the history.
    As for the experiment it truly is genius. So simple yet astonishingly accurate. It's interesting how they've managed to notice charge quantization at this "macroscopic" level. I guess particle size was small enought that a small carge variation could have noticable effect on the result..:D

    • @jkzero
      @jkzero  28 днів тому +2

      Yeah, Millikan was a jerk (there are many other stories about him, this was not an isolated incident) but also brilliant designing simple and beautiful experiments reaching exquisite levels of accuracy and precision. There is a follow up video coming, as I said, Millikan was not done yet.

    • @t850
      @t850 28 днів тому

      ​ @jkzero ...it's ironical how we are tought to purchase science to expand our understanding of the universe (ourselves), but once it becomes a career it just becomes "currency" for social status improvement...

    • @jkzero
      @jkzero  27 днів тому

      @@t850 I am so happy since I left academia; so many things are wrong there

    • @t850
      @t850 27 днів тому +1

      @@jkzero ...whole system is upside down. Only thing that matters is production of scientific papers at any cost. It's not the curiosity that drives the scientific research but the quotas that scientists have to meet. Sad, but it is the truth.
      Even though you left academia, you still kept your enthusiasm high and math skills sharp. Put them to good use on the next video...;)

    • @jkzero
      @jkzero  27 днів тому +2

      @@t850 the only thing that I miss from academia is teaching, I loved that and my students liked my style. I always loved taking beyond the content, I liked to share the stories behind, the people, the historical context... I could not shut up about it, I guess this is how this channel started

  • @KALE18
    @KALE18 24 дні тому +1

    Thanks you for your advice

  • @ethanfletcher9635
    @ethanfletcher9635 23 дні тому

    It would make me so happy if there was ever a video on the Lorentz gamma factor. I never have figured out its derivation. Love these videos!

    • @jkzero
      @jkzero  23 дні тому

      Thanks for your feedback, I am glad you find the content of value. A video analyzing Einstein's original paper on special relativity is on my to-do list.

  • @alexandervoytov4966
    @alexandervoytov4966 28 днів тому +1

    I used to study fog formation back in 1980x with ultrasound. One of my point was a gravity shaping droplets. In theory there is an influence shaping droplets out of spheres. In practice with my instruments I didn’t see that. Spheres were a good assumption.

    • @jkzero
      @jkzero  27 днів тому +1

      Thanks for sharing your experience, it sounds amazing. Were you trying to make use of these deformed droplets in any way?

    • @alexandervoytov4966
      @alexandervoytov4966 27 днів тому

      @@jkzero That time I used to be a reseacher at area of fluorine chemistry as energy releasing with chemical reactions with hydrocarbons. I had created a hydrocarbon(kerosene, alcohol,etc) cloud first. The next step was to incert distributed fluoride powder into the hydrocarbon cloud to see the reaction. My milestone was to study droplets distribution by size inside the cloud with ultrasound generator. I used to develop some analytic model of such test. Droplets shape was a parameter. Droplets were smallest in the center of my cloud with some increase of size and decrease to vapour on the edge. 2 different models: 1. droplets have sperical shape, differen sizes; 2. droplets have gravitational shape, different sizes. Each model will reflect ultrasound little bit differently. Practically, sperical model described test well enough.

    • @jkzero
      @jkzero  27 днів тому +1

      @@alexandervoytov4966 Thank you so much for sharing your story, it sounds like fascinating industrial work. I recently was involved in a project studying droplet size distributions for sprays and agricultural applications but my work was mostly as a statistical modeler rather than your more hands-on experience. Great to have in the channel, thanks for watching and, again, for sharing your experience. I am glad my video brought back some good memories.

  • @GeoffryGifari
    @GeoffryGifari 29 днів тому +4

    Huh they used Stoke's law on drag force, which made it unnecessary to measure droplet radius with the microscope directly
    very clever

    • @jkzero
      @jkzero  28 днів тому +3

      the use of Stokes' law was inspired by early experiments at J.J. Thomson's lab; but yeah, Millikan took it to another level and achieved insane levels of accuracy and precision.

  • @fabienleguen
    @fabienleguen 28 днів тому

    High quality video on a poorly known (even by average scientists) milestone of science but yet very fondamendal. I felt the same jaw-drop moment after seeing your video on Planck derivation of his law. Only 700 views, your channel is clearly underrated ! I bet it will grow to an average of 10^5 views per vid / 10^6 subscribers in the near future. Keep it up and thank you very much for this very instructive content !

    • @jkzero
      @jkzero  27 днів тому

      Thanks for the positive feedback, I cannot complain about the audience, I reached 20k subscribers and I have been making videos only for a few months. I am glad you find the content engaging, I love this kind of stories and my intention is to be able to transmit what I feel with them.

  •  29 днів тому +7

    I learned a lot from this video! thanks
    One thing that is normally not mentioned, is that Townsend and Thomson measured the electron charge before MIllikan, and got the value 1E-19 C (which compares pretty well with Millikan's results).
    If the previous result was not so bad, why was the community did not accept it?
    In books, you can often find people saying that Millikan was the FIRST, but this is wrong.

    • @jkzero
      @jkzero  28 днів тому +8

      Great point! Thomson, Townsend, and Wilson had reported the value 10^{-19} C; however, their estimate used several assumptions and the uncertainties were quite large. The fact that they could observe droplet for very small amount of time (contrary to Fletcher-Millikan that could control their droplets at will) produced very unreliable results. They also assumed that each drop carried a single electron of charge; contrary to Millikan's idea of letting the droplets capture charges from the ionized air in any amount and then determine that the total charge was an integer multiple of e. The experiments of Thomson, Townsend, and Wilson were not less important, after all, they were Millikan's inspiration, but with Fletcher, Millikan designed a beautifully simple and insanely accurate experiment.

    •  28 днів тому +4

      @@jkzero Thank you! This answer really clarified a lot. I have always been confused by this!

    • @jkzero
      @jkzero  28 днів тому +1

      @ here is a brief and interesting article about the work of Thomson, Townsend, and Wilson and some comparison to Fletcher-Millikan www.nature.com/articles/131569a0.pdf

  • @Unique-Concepts
    @Unique-Concepts 27 днів тому +1

    I love this channel!

    • @jkzero
      @jkzero  26 днів тому

      thanks for watching

  • @NondescriptMammal
    @NondescriptMammal 24 дні тому

    Excellent presentation! Very interesting to have a history of this with such a detailed description of the experiment. I often wonder how exactly such experiments were done, but usually the details are glossed over or omitted altogether, and it is not easy to find such descriptions as this.

    • @jkzero
      @jkzero  23 дні тому +1

      When I was a physics student I learned the solutions to the problems of the time but I remember that the lack of context and details was quite unsatisfactory. Now that I have time, I decided to dig deeper, read parts of the original papers, and I decided to share the details and found that the stories get even more fascinating.

    • @NondescriptMammal
      @NondescriptMammal 23 дні тому

      @@jkzero It is greatly appreciated! You described my exact frustration at the lack of context and details. You do a great service with this work, in my opinion. The historic perspective you provide not only makes the subject matter more interesting, it brings deeper meaning to it as well.

    • @jkzero
      @jkzero  22 дні тому +1

      @@NondescriptMammal Millikan, round 2 coming soon

    • @NondescriptMammal
      @NondescriptMammal 22 дні тому

      @@jkzero I look forward to it! I also like how you give proper credit to the experimental physicists whose names are so often forgotten to history, while the theoreticians bask in all the glory. It is nice to see their contributions are not always overlooked.

  • @mrshodz
    @mrshodz 17 днів тому

    Great explanation. Keep it up.

    • @jkzero
      @jkzero  10 днів тому

      Thanks, the follow-up story is published now

  • @thecwd8919
    @thecwd8919 23 дні тому +1

    The original apparatus is stored at the Musuem of Science and Industry in Chicago.
    It's one of the cooler but less noticeable exhibits.

    • @jkzero
      @jkzero  23 дні тому +2

      I have visited this museum some years back. It is unfortunate that the Fletcher-Millikan apparatus doesn't look as impressive as it really is, it just look like an old pressure cooker. Its looks hides its historic relevance.

  • @KipIngram
    @KipIngram 5 днів тому

    Wow - this was a BRILLIANT experiment.

    • @jkzero
      @jkzero  5 днів тому

      oh yes, it was. When people talk about the oil-drop experiment they usually say "yeah, Millikan suspended an oil drop and set electrostatic force equal to weight, and bam, you get the charge" but the experiment was way more clever that that.

  • @feelthebluesgaming7630
    @feelthebluesgaming7630 27 днів тому +1

    Great explanation and storytelling! I appreciate this as a teacher because I always seek to explain the details, but it can be hard to find. Can you recommend a good source that includes the rigorous details of such experiments?

    • @jkzero
      @jkzero  26 днів тому

      Thanks, I'm glad you like the video and story. I miss teaching and this channel has been a way to do one of my favorite activities: talk about physics including historical aspects. I do not have a particular source, I like to read the original papers but sometimes they are too technical or use old-fashioned style that make them hard to read. In that case, a great source is papers in journals of history of science as well as teacher-oriented journals like the American Journal of Physics.

  • @ConnorMcCormick
    @ConnorMcCormick 28 днів тому +2

    Thanks!

    • @jkzero
      @jkzero  27 днів тому

      Thanks so much for supporting me to keep making these videos!

  • @jerrycornelius5986
    @jerrycornelius5986 24 дні тому +1

    Very interesting

  • @BritishBeachcomber
    @BritishBeachcomber 28 днів тому +1

    As a 10 year old, discovering science. I read it as *the Milkman experiment.*

    • @jkzero
      @jkzero  27 днів тому

      Milkman is a standard joke every time the oil-drop experiment is described

  • @aymanmansoori8936
    @aymanmansoori8936 27 днів тому

    Wow, I really did not have any idea that there was another scientist behind the measuring pf the charge of the electron.
    Even in school textbooks, only Millikan's name is mentioned.

    • @jkzero
      @jkzero  26 днів тому

      It is not surprising that Millikan appears with all the credit, firstly the story of Fletcher is quite unknown, plus textbook tend to simplify the stories for the sake of simplicity

  • @boazbrisker81
    @boazbrisker81 5 днів тому

    Great video 🙏🏻

    • @jkzero
      @jkzero  5 днів тому

      I am glad you liked the content and thanks for watching. I am always curious to know what brings viewers to the channel, were you searching for something in particular or did the 'mighty algorithm' find you?

  • @dziban303
    @dziban303 28 днів тому +1

    gracias

    • @jkzero
      @jkzero  27 днів тому

      de nada, gracias por la visita.

  • @johnm.v709
    @johnm.v709 27 днів тому

    Sir, - Electron model
    On 4 foot stone nearing completion.

  • @padraiggluck2980
    @padraiggluck2980 24 дні тому

    I read years ago that Millikan averaged ~900 measurements to get his famous result.

    • @jkzero
      @jkzero  23 дні тому

      In his 1911 paper, Millikan refers to hundreds of droplets but I could imagine a few extra hundreds for his final 1913 paper

  • @supreetsahu1964
    @supreetsahu1964 29 днів тому +3

    Did millikan really disprove any einstein work or was that a joke?

    • @jkzero
      @jkzero  28 днів тому +7

      The end of the video was intended as a cliffhanger but no joke. That was Millikan next goal: design another high-precision experiment to prove that Einstein's quantum theory was nonsense. You can guess the outcome of that experiment. A second part on Millikan coming soon.

    • @supreetsahu1964
      @supreetsahu1964 28 днів тому +1

      ​@@jkzero got it 👍

  • @hedgehog3180
    @hedgehog3180 22 дні тому

    0:41 We did that experiment in my physics class.

    • @jkzero
      @jkzero  21 день тому

      yeah, I remember doing that experiment to deflecting electrons to determine their mass-to-charge ratio

  • @GeoffryGifari
    @GeoffryGifari 29 днів тому +3

    huh... why would oil droplets survive longer in air anyway? surface tension of water droplets gets disturbed by air humidity? what about mercury (and it being conductive metal)?

    • @juanro22
      @juanro22 29 днів тому +4

      Water evaporates faster than oil, specially at those minuscule sizes.

    • @jkzero
      @jkzero  28 днів тому +6

      to see the droplets they use a powerful lamp, which quickly evaporated the water droplets; if you check Millikan's 1911 paper, section 13 is about other substances used. They experimented with different types of oil and got consistent results. Mercury was proposed in the early stages but not pursued mostly for its high density, which would force the use of extremely tiny droplets and in this limit Brownian motion would ruins the measurements.

  • @khiemgom
    @khiemgom 27 днів тому

    This is just a joke but are you taking inspiration from the a level course because all of your recent vids are somehow related to my physic a level paper lol. Thks for that ig

    • @jkzero
      @jkzero  26 днів тому +1

      I'm glad that the content in the channel is somehow aligned with your studies, I hope the presentation was clear and useful

    • @khiemgom
      @khiemgom 26 днів тому

      @@jkzero it was rlly helpful and definitely better than the handed down formula approach to teaching in the course book

    • @khiemgom
      @khiemgom 26 днів тому

      @@jkzero tho i have a question, how can the velocity of the drop be determined accurately

    • @jkzero
      @jkzero  26 днів тому

      @@khiemgom brilliant!

    • @jkzero
      @jkzero  26 днів тому

      @@khiemgom they had a graduated viewer so they could count the number of steps (a few millimeters) in a given time, they literally used hand-held stop watches, one each (Millikan and Fletcher) to crosscheck each other's measurements.

  • @empty-me
    @empty-me 17 днів тому

    wow

  • @gojosatoruisdead
    @gojosatoruisdead 21 день тому

    we got electrons oiled up before GTA 6.

    • @jkzero
      @jkzero  21 день тому

      I had to google the meaning of GTA 6 and now feel old

  • @gametimewitharyan6665
    @gametimewitharyan6665 29 днів тому

    9:12 I notice smth :D

  • @cfu11er
    @cfu11er 27 днів тому +1

    There's a wonderful episode (they all are, for those unfamiliar) of The Mechanical Universe dedicated to the Oil Drop Experiment
    ua-cam.com/video/sUc13Q8CF3s/v-deo.html

    • @jkzero
      @jkzero  26 днів тому

      thanks for sharing this; I took the image of the Wilson cloud chamber from that episode, it is in fact listed on the list of credits. And I fully agree: The Mechanical Universe is a fantastic series

  • @michaelrtreat
    @michaelrtreat 26 днів тому

    The politics of science at work.

    • @jkzero
      @jkzero  25 днів тому

      that's right, as most human endeavors egos and abuse of power play a role

  • @felipemonteiro5877
    @felipemonteiro5877 28 днів тому +2

    Quantum mechanics is beautiful, but the people behind it could be so awful.

    • @jkzero
      @jkzero  27 днів тому +3

      yeah, this is a human endeavor and as such the best and the worst of human nature appears. Nightmare dramas are not the exception in academia, I saw so much mistreatment of people and abuse of power that I am glad I am not part of that environment anymore. Leaving academia was one of the best decisions. Anyway, Millikan was a jerk and he was not done, next part coming soon so stay tuned.

    • @johnm.v709
      @johnm.v709 27 днів тому

      "Quantum Mechanics" - great

  • @KipIngram
    @KipIngram 5 днів тому

    Oh, leaving Fletcher off of the paper was a jerk move.

    • @jkzero
      @jkzero  5 днів тому

      Fully agree. I learned about this story after knowing about the other stories about Millikan so I didn't surprised me, but sadly this kind of behavior is quite common in academia.

  • @danamarcy5414
    @danamarcy5414 26 днів тому

    Millikin is a typical arrogant academic only interested in self agrandisement. Poor Fletcher the forgotten man. Bad Science. Dana Marcy

    • @brucemcpherson8832
      @brucemcpherson8832 26 днів тому

      Worse still he faked his results and then lied about it
      " Awkwardly, an examination of Millikan's private laboratory notebooks indicates that he did not in fact include every droplet for which he recorded data. He published the results of measurements on just 58 drops, whereas the notebooks reveal that he studied some 175 drops in the period between November 11th, 1911 and April 16th, 1912. In a classic case of cooking, the accusation goes, he reported results that supported his own hypothesis of the smallest unit of charge and discarded those contrary results that would have supported Ehrenhaft's position. And, to make matters very much worse, he lied about it. Millikan's 1913 paper contains this explicit assertion: "It is to be remarked, too, that this is not a selected group of drops, but represents all the drops experimented upon during 60 consecutive days, during which time the apparatus was taken down several times and set up anew." (Emphasis in the original). Thus, Millikan is accused of cheating and then compounding his cheating by lying about it in one of the most important scientific papers of the 20th century."

    • @jkzero
      @jkzero  25 днів тому

      unfortunately, this is a common behavior in academia until this day

    • @jkzero
      @jkzero  25 днів тому +1

      I am aware of these accusations against Millikan; however, for I have read, careful examination of the notebooks and experimental notes revealed that there was no misconduct and the removed data were scientifically justified.

  • @jonludwig8233
    @jonludwig8233 27 днів тому

    Thanks!

    • @jkzero
      @jkzero  27 днів тому

      Thanks so much for supporting me to keep making these videos!