Episode 12: The Millikan Experiment - The Mechanical Universe

Episode 12. The Millikan Experiment: A dramatic recreation of Millikan's classic oil-drop experiment to determine the charge of a single electron.
“The Mechanical Universe,” is a critically-acclaimed series of 52 thirty-minute videos covering the basic topics of an introductory university physics course.
Each program in the series opens and closes with Caltech Professor David Goodstein providing philosophical, historical and often humorous insight into the subject at hand while lecturing to his freshman physics class. The series contains hundreds of computer animation segments, created by Dr. James F. Blinn, as the primary tool of instruction. Dynamic location footage and historical re-creations are also used to stress the fact that science is a human endeavor.
The series was originally produced as a broadcast telecourse in 1985 by Caltech and Intelecom, Inc. with program funding from the Annenberg/CPB Project.
The online version of the series is sponsored by the Information Science and Technology initiative at Caltech. ist.caltech.edu
©1985 California Institute of Technology, The Corporation for Community College Television, and The Annenberg/CPB Project

[@usandmexico]

Robert A. Millikan is my inspiration. I don't ever expect to reach his greatness, but like him, a lack of support as an engineer has made me doubt, but not give up on, my ability as an engineer.

[@DarwinsChihuahua]

Don't forget about the bread particle called the "crouton".

[@marshacd]

A thousand thumbs-up!

[@baobaota8802]

DEADASS-

[@JMDinOKC]

And don't forget about the French clothing particle called the "bouton."

[@nagone11]

lol

[@powerdriller4124]

And what about that unit of fending off bugs in human cavities? The "condon" .

[@clarencegreen3071]

As an undergraduate, I was fortunate to be able to play around with a Millikan apparatus at my leisure, and I spent many hours "chasing drops." My approach was to find the charge on a particular drop, and my precision could be judged by how closely the charge I found came to an integral number of electronic charges. After observing one drop for a minute or so, and recording data, it suddenly began to act quite differently. I stuck with it and recorded more data. Subsequent calculations indicated that the drop had lost (or gained) ONE electron. At that moment I felt like I had witnessed something special and noteworthy -- to see the effect of a single electron.

[@kel-A-3414]

I have so many questions regarding this experiment. Why is there an inherent assumption that the charge comes from the electron. And that the value is the smallest possible unit of charge. I have watched multiple videos on this experiment and I still don't understand the basis/concept behind it. Can you please elaborate on what happens in the chamber? From what I gather, there are free-floating, ionized electrons and the droplets condense on them. Is that what is happening?

[@clarencegreen3071]

@@kel-A-3414 The droplets are formed by the atomizer above the chamber and then fall through a small hole into the chamber. They are not formed by condensation inside the chamber. J. J. Thompson, in 1897, determined that the electron carried a negative charge. At the time of the Millikan experiment, the electron was the only particle known to carry a negative charge. When it was determined that the oil drops were negatively charged, the assumption was that they had gained electrons. In the course of the experiment, the charges acquired by the droplets were found to be an integral number times a basic unit of charge. This was taken to be the charge on a single electron. It was assumed to be the smallest unit of charge because a smaller unit had never been observed. My suggestion is for you to search for articles describing the discovery of the electron, proton, and neutron. Important names are Thompson, Goldstein, Chadwick, and Rutherford, among others.

[@kel-A-3414]

@@clarencegreen3071 ohh ok. That makes sense. The part about how the charge was determined makes sense. The whole thing started bugging me when I found out quarks had fractional charges. And then it put into question the validity of the electron being the fundamental unit of charge. And if charge is quantized, how do u get "particles" with a fraction of something considered to be the smallest possible value. It just raises a lot of confusing questions. I guess I have to start afresh.

[@paulg444]

Regarding his notes, we have to recognize that as he is collecting data and analyzing it his mind is always ahead of what he has already published, so that his observations are in real time informing his mental model of the size of the electron. He knows where the preponderance of evidence is pointing and his notes are an honest representation of his thinking. That he expressed more confidence in his result a bit sooner than a court of law might accept is no fault of the scientist. His goal is not that of a prosecutor, it is to advance our understanding of nature.

[@westinthewest]

Wikipedia: ' The oil drop experiment was performed by Robert A. Millikan and Harvey Fletcher. ' It also seems that a deal was struck by Millikan to force Fletcher to relinquish authorship in exchange for his PhD, and the pulling of strings at Bell Laboratories. Perhaps we should be careful with the accolades, medals and prizes we bestow on each other, as it encourages motivations which might affect how an oil drop moves.

[@sphakamisozondi]

Also, it was, Fletcher's idea to use oil instead droplets of water. He experimented with dozens of different oils, and he found the one that would best fit the experiment.

[@brainstormingsharing1309]

Absolutely well done and definitely keep it up!!! 👍👍👍👍👍👍

[@sammiller552]

11:32 experiment starts to be explained here

[@sope4338]

remarkable simplicity and determination. little by little we can do allot.

[@universocalculado4639]

Robert Andrews Millikan foi um físico experimental exemplar . Quando eu me tornar físico e fizer algum experimento , eu já sei de onde tirar minha inspiração . Há eu aprendi uma fórmula nova , nunca tinha visto essa da força da viscosidade Fv = 6 . 3,14rnv .

[@openyoureyesandseethefutur3382]

was that Gilda Radner as a student in this video?

[@Tadesan]

Pers-ons..... Awwwwwwwweeee...... I learned something today!

[@abellizandro3550]

Thanks a lot

[@timwhite7127]

He neglected to mention that in addition to the -on suffix for units of a greater body of composition, that humanity, while containing the pers-on also has an unusual portion of units known as the mor-on.

[@daviddonkiv8112]

I am dead

[@kingvic7361]

This is what coronavirus is making me do

[@ayoubsbai6339]

ikr

[@shoopinc]

Not a bad thing at all

[@deborahfranza2925]

This guy's a riot

[@douglasstrother6584]

High-power vacuum microwave devices, like Travelling Wave Tubes, still go through a bake-out before pinch-off to clean-out the vacuum bottle.

[@sethgilchrist8436]

If you're noticing a large delay between the audio and the video, try a different browser. In Chrome, I get the Annenberg Media logo at the start of the video, which throws off the audio by ~16 seconds. In Microsoft Edge, the logo is shown at the end of the video and everything syncs perfectly. No idea why this works, but I just noticed it after suffering through like a dozen of these out of sync.

[@RM-gm7lu]

Cannot get enough...

[@rockets4kids]

Aah the days when every home had a particle accelerator in the living room...

[@SMD1999]

wonderfuk stuff :))

[@brendanburkhart9470]

Is anyone else experiencing a delay in the audio that doesn't line up with the visuals? It only a second or two but it throws off the big lab notebook reveal. I was trying to use this for a class of mine.

[@joelwong62]

Same. I don't remember the Annenberg Media intro from before, and I suspect it being edited in recently contributed to the whole audio delay.

[@geirtwo]

When I watch it the audio happens 16 seconds before the image, all the videos that have had this Annenberg logo inserted have been vandalized in this way. I was hoping these videos would stay relatively unnoticed here on youtube because in this world things that are this great tends to be destroyed. These are the episodes currently affected: 5, 7, 9, 10, 11, 14, 15 , 16, 17, 19, 24, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 40, 41, 42, 49, 50, 51, 52.

[@imtiazhassan6242]

I wish they showed what the oil drops looked like in the apparatus.

[@clarencegreen3071]

As I remember from doing the experiment almost 60 years ago, the droplets appeared as tiny points of light against a dark background. I could not tell that they were small spheres, sort of like looking at a bright star on a dark night. Sometimes if you were too aggressive with the atomizer, you would get so many droplets in the field of view that an individual drop was hard to distinguish. In that case, you could adjust the voltage and run the drops up and down until you cleared most of them out. It was great fun, actually, for a young kid at least.

[@kel-A-3414]

@@clarencegreen3071 can you please elaborate on what happens in the chamber? From what I gather, there are free-floating, ionized electrons and the droplets condense on them. Is that what is happening?

[@diamonddeuce2288]

Napolean Dynamite at 2:47

[@trevorburke9924]

4:49 Marks the Best 30 seconds of the whole video.

[@allannowak1406]

Trevor Burke electrons travel through things thats a jew concept

[@deanbaird]

Instructors: to keep students engaged while they watch this episode, consider using this question set. www.teacherspayteachers.com/Product/The-Mechanical-Universe-Episode-12-The-Millikan-Experiment-5070444

[@rakshitpuri4192]

"persons"

[@douglasstrother6584]

Physics: the Fall Back Career!

[@camilogangotena5059]

What do you mean? @Douglas Strother

[@douglasstrother6584]

@@camilogangotena5059 He had a greater interest in Greek, Literature and Mathematics before diving into Physics.

[@camilogangotena5059]

@@douglasstrother6584 Oh I get it! I was a bit concerned because I thought you meant physics in general! Haha. Thank you very much for the clarification and for that interesting fact! Best regards.

[@douglasstrother6584]

@@camilogangotena5059 You bet!

[@douglasstrother6584]

@@camilogangotena5059 He also did excellent measurements on the Photoelectric Effect.

[@openyoureyesandseethefutur3382]

gilda rader at 3:07

[@louiswonnell6042]

I was beginning to wonder if i was crazy, is that really her? She would have been alive, yes? If that isn't her it's the best clone possible.

[@avishekmukhopadhyay6086]

Correction: Marconi was not the first to make radio waves, it was indian scientist Jagadish Chandra Bose. Marconi somehow stole his idea and patented it before him.

[@reason827]

He discovered a fundamental law of physics.

[@profnerd7357]

Can someone explain me the "persons" joke?

[@goosew3266]

This is so annoying. Whoever put the Annenberg Media logo at the front of these videos really made a mistake. It throws the whole audio off the video. I have watched these lectures more than once, so I know there was not always this Annenberg Media introduction. Can someone please put it back to what it was?

[@paulgaskins7713]

27:08 ….not anymore in many fields

[@mikev4621]

The CRT was invented in 1897 - not quite "the middle of the 19th century"

[@cristinamariotta1210]

Millikan high school RAM 🐏 🙌 👌 😳 😎 😍 Long Beach School district 1956

[@razzdazzjazz92]

I always pronounce his name as Milkman

[@louiswonnell6042]

I think that person joke is a capital offense. If he's still alive today, arrest him.

[@powerdriller4124]

In these whinny snowflake Millenials´ times, a case can be brought up about that he was insulting humans (injuring their "self-estime") by comparing them with sub-atomic particles, with "the lowest of the low´s."

[@gordonpeacman2126]

Rutherford, a N.Z.was, who split the atom in 1917.....

[@421sap]

In Jesus' Name, Amen. God bless you!✨✝️

[@andyjones2457]

It's funny how Millikan used to be such an advocate for the scientific method, yet didn't publish a lot of results he gathered during this experiment, he's a bit of a hypocrite to be honest

[@JadeHare1]

Andrew Jones As every peer-reviewed papers, always the results are happy endings...crazy

[@dbappio]

DOO DO DOO *DOODO DOOOOOOOOOOOOOO*

[@Knaeben]

I thought the scientific method was to figure out what brings profit to your corporation and make sure you get those results.

[@addisonharris8062]

where my cbhs bois at