4 ms·

Perhaps we can spare future generations of physics undergrads from the monotony of examining falling oil drops through a microscope.

mhh__ 6y ago
Do undergrads even cover it? The fraud/bias aspects of the experiment are interesting
- mannerheim 6y ago
  We reproduced the experiment in one of my laboratory courses. I don't remember if the controversial aspects of Millikan's data collection were discussed; whether it could even be called fraudulent seems somewhat debatable. But interestingly, Feynman had a quote about Millikan's successors[0]: > We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off, because he had the incorrect value for the viscosity of air. It's interesting to look at the history of measurements of the charge of the electron, after Millikan. If you plot them as a function of time, you find that one is a little bigger than Millikan's, and the next one's a little bit bigger than that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher. > Why didn't they discover that the new number was higher right away? It's a thing that scientists are ashamed of--this history--because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong--and they would look for and find a reason why something might be wrong. When they got a number closer to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that. We've learned those tricks nowadays, and now we don't have that kind of a disease. A classic example of herding[1]. 0: https://www.lockhaven.edu/~dsimanek/cargocul.htm https://www.lockhaven.edu/~dsimanek/cargocul.htm 1: https://fivethirtyeight.com/features/heres-proof-some-pollsters-are-putting-a-thumb-on-the-scale/ https://fivethirtyeight.com/features/heres-proof-some-pollst...
  - selimthegrim 6y ago
    He also probably took more credit to himself than he deserved - https://en.wikipedia.org/wiki/Harvey_Fletcher https://en.wikipedia.org/wiki/Harvey_Fletcher
    - mannerheim 6y ago
      Having had to reproduce the experiment myself, I would certainly have offloaded that work on a grad student if I could have.

mhh__ 6y ago

Do undergrads even cover it? The fraud/bias aspects of the experiment are interesting

mannerheim 6y ago
We reproduced the experiment in one of my laboratory courses. I don't remember if the controversial aspects of Millikan's data collection were discussed; whether it could even be called fraudulent seems somewhat debatable. But interestingly, Feynman had a quote about Millikan's successors[0]: > We have learned a lot from experience about how to handle some of the ways we fool ourselves. One example: Millikan measured the charge on an electron by an experiment with falling oil drops, and got an answer which we now know not to be quite right. It's a little bit off, because he had the incorrect value for the viscosity of air. It's interesting to look at the history of measurements of the charge of the electron, after Millikan. If you plot them as a function of time, you find that one is a little bigger than Millikan's, and the next one's a little bit bigger than that, and the next one's a little bit bigger than that, until finally they settle down to a number which is higher. > Why didn't they discover that the new number was higher right away? It's a thing that scientists are ashamed of--this history--because it's apparent that people did things like this: When they got a number that was too high above Millikan's, they thought something must be wrong--and they would look for and find a reason why something might be wrong. When they got a number closer to Millikan's value they didn't look so hard. And so they eliminated the numbers that were too far off, and did other things like that. We've learned those tricks nowadays, and now we don't have that kind of a disease. A classic example of herding[1]. 0: https://www.lockhaven.edu/~dsimanek/cargocul.htm https://www.lockhaven.edu/~dsimanek/cargocul.htm 1: https://fivethirtyeight.com/features/heres-proof-some-pollsters-are-putting-a-thumb-on-the-scale/ https://fivethirtyeight.com/features/heres-proof-some-pollst...
- selimthegrim 6y ago
  He also probably took more credit to himself than he deserved - https://en.wikipedia.org/wiki/Harvey_Fletcher https://en.wikipedia.org/wiki/Harvey_Fletcher
  - mannerheim 6y ago
    Having had to reproduce the experiment myself, I would certainly have offloaded that work on a grad student if I could have.