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.
Unfortunately he was a bit too optimistic there :)
The graph in the answer here https://hsm.stackexchange.com/a/5346 suggests that Feynman’s statement is a thick layer of interpretation over the actual data.
The actual data show numbers all over the chart before 1940 after which the number seem to stabilize.
The best I would be willing to say is that Millikan got a lower mean, may have been over-aggressive in discarding data for publication, and only after 1940 did we get more precise data.
Unfortunately he was a bit too optimistic there :)
Re: The charge on an electron.
The graph in the answer here https://hsm.stackexchange.com/a/5346 suggests that Feynman’s statement is a thick layer of interpretation over the actual data.
https://i.stack.imgur.com/WtmUj.png
The actual data show numbers all over the chart before 1940 after which the number seem to stabilize.
The best I would be willing to say is that Millikan got a lower mean, may have been over-aggressive in discarding data for publication, and only after 1940 did we get more precise data.