How the Oil Drop Experiment Discovered the Charge of the Electron

Robert Millikan and Harvey Fletcher were two physicists now known for discovering the mass and the charge of the electron. They did this through their famous "Oil Drop Experiment" in which they hovered electrically charged droplets of oil in a chamber with an electric field applied. This video covers the history of Millikan and Fletcher, and discusses some controversies that followed the experiment. Millikan won the Nobel Prize in Physics in 1923 for this experiment.

[@LiborTinka]

You can also make a video about Robert Mulliken and his contribution to chemistry (the concept of electronegativity) because both names: R. Mulliken and R. Millikan are easily confused - yet they both won the Nobel Prize except one was in physics (1923) and the other in chemistry (1966). I remember my confusion when studying the history of chemistry, knowing only about the 'oil drop guy' 🙂

[@RationalThinker118]

Nice idea! Thanks for the insight.

[@JanBruunAndersen]

I and my classmates did this experiment in gymnasium (college?) back in 1978 or so.

[@RationalThinker118]

Doing this in person must be an amazing experience!

[@RossMarsden]

I did this experiment for my second year Physics course at Auckland University, New Zealand. It was amazing and a privilege to repeat one of the greatest experiments in Physics. I passed the course.

[@JP-re3bc]

Looks like he was not a nice person.

[@ahbushnell1]

I did the experiment in a physics lab in college. Very interesting. We spent 9 hours taking data. We measured the speed of the drops for zero electric field. positive and negative. From that you can cancel out the drag of the drop going through the air. We got an excellent result. We also did E/M. great video.

[@RationalThinker118]

Thank you! 9 hours is a lot of data I bet.

[@mechez774]

Love the details of the experiments. 99.9% of videos just state determined facts without at all discussing the experiments. A notable exception is maybe the double slit experiment

[@RationalThinker118]

Thanks! I always want to include the science along with the history for sure.

[@alphalunamare]

I have yet to see a description of the double slit experiment that sits well with the average knerd. I mean, how accurate is the lasar gun shooting electrons at the two slits, and how small are the electrons compared to the slits? I can never get a conceptual mind picture of what is going on. Why? because people just accept it and don't bother to explain it other than from wave functions.

[@rgfrw]

I had read that among Fletcher's papers which you mentioned was a letter by Fletcher in which he stated that he, not Millikan suggested the use of oil drops rather than water. This would seem to make Fletcher a major contributor to the work rather than just a technician. The letter also discussed his conversation with Millikan in which Millikan said he, Fletcher, could be the sole author on another paper while Millikan was the sole author of the oil drop experiment.

[@RationalThinker118]

I was also thinking it could have been a possibility that the experiment's credit could've/should've gone solely to Fletcher... he should've at least been included for sure.

[@stevebabiak6997]

0:30 - spellcheck might have corrected “defeleted” into “deflected”

[@onradioactivewaves]

Great video

[@fredsalter1915]

6:42 I wonder who the young black man is in this image. Very interesting!

[@user-xy9ip4my3k]

Can you do a video On physics of startrek deepspace nine

[@glenmartin2437]

Thank you.

[@RationalThinker118]

Thank you for watching!

[@Ansh.917]

Make a video on maxwell 4 equations

[@bicivelo]

Love these videos. Liked and subscribed.

[@RationalThinker118]

Glad you like them!

[@bicivelo]

@@RationalThinker118 i love learning!! Thank you 🤓🤓

[@JxH]

"...mass to charge ratio..." I kept hearing *Master Charge* ratio (MasterCard until 1979).

[@dcbc9619]

I'm in, subscribed!

[@RationalThinker118]

Appreciate it so much!

[@philoso377]

Nice video and presentation. Are we nuts? Oil is oil and not electron.

[@RationalThinker118]

Thank you. Oil is oil but it has electrons! Extra electrons too when in the ionized chamber

[@philoso377]

@@RationalThinker118are we nuts? Oil composed of numerous molecules of atoms and electrons. That wouldn’t make it an electron.

[@purplerpenguin]

The oil is neutral, apart from one or more electrons acquired from the ionization.

[@mechez774]

@philoso377 Technically speaking I don't believe we are nuts. Most of us anyway. But nuts and seeds are a great source of healthy oils.

[@philoso377]

@@purplerpenguinare we assuming that when oil particle receive charge it become the oil particle itself plus one and only one electron? What make us think so? Electron = subatomic particles plus charge. Electron is a composition of two independent entities and not single. oil doesn’t need additional electron in order to be charged or carry charge.

[@GmodErki]

Have you considered making the music/ambience slightly louder in your videos? I know it's there but I can't hear it at all :')

[@RationalThinker118]

Sure I can adjust, I turned it down a while ago because people were saying it was too loud

[@dogcarman]

Oh please don’t. Loud music makes it very hard for non-neurotypicals like me to concentrate on the content.

[@lednique2742]

There's really no need to show stupid stock video of two guys in lab coats to accompany the mention of "scientists" in the video. This kind of stuff really detracts from an otherwise very informative video. From now on, please assume we know exactly what a scientist looks like!

[@RationalThinker118]

Well of course I don't assume you don't know what a scientist looks like... but thank you for the critique.

[@AntonioGuidetti-ww8rb]

en.m.wikipedia.org/wiki/Oil_drop_experiment read Controversy and Millikan's experiment as an example of psychological effects in scientific methodology

[@RationalThinker118]

Feynman put it brilliantly.