Milliken's oil drop experiment and the electron

[steve_bank]

https://en.wikipedia.org/wiki/Oil_d...ychological_effects_in_scientific_methodology

'...In a commencement address given at the California Institute of Technology (Caltech) in 1974 (and reprinted in Surely You're Joking, Mr. Feynman! in 1985 as well as in The Pleasure of Finding Things Out in 1999), physicist Richard Feynman noted:


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 an electron, after Millikan. If you plot them as a function of time, you find that one is a little bit 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 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 close 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 ... [10][11]...'

How science works. Eventually truth prevails.

 

[skepticalbip]

That history does point out a rather insidious problem in measurement, experimenter bias. The same can be seen in early measurements of the speed of light. The problem being a combination of the experimenter believing they know the answer before the test and the extreme difficulty of making repeatedly accurate measurements.

A small, nit picking, correction to the description of the Millikan oil drop experiment - it actually allows for a measurement of the charge to mass ratio of the electron not just the charge. The mass must be accurately known to calculate the charge from the result of the test.

 

[steve_bank]

That history does point out a rather insidious problem in measurement, experimenter bias. The same can be seen in early measurements of the speed of light. The problem being a combination of the experimenter believing they know the answer before the test and the extreme difficulty of making repeatedly accurate measurements.

A small, nit picking, correction to the description of the Millikan oil drop experiment - it actually allows for a measurement of the charge to mass ratio of the electron not just the charge. The mass must be accurately known to calculate the charge from the result of the test.

That is what Feynman was talking about, confirmation bias. It can be subtle and creep up on you.

That is why experiments are independently repeated and discrepancies worked through.

 

[steve_bank]

https://archive.org/details/TheElectron

If you want to get a glimpse of a scientific investigation and analysis you can down load his book. I used to have a copy. Not a lot of math/

 

[bilby]

That history does point out a rather insidious problem in measurement, experimenter bias. The same can be seen in early measurements of the speed of light. The problem being a combination of the experimenter believing they know the answer before the test and the extreme difficulty of making repeatedly accurate measurements.

A small, nit picking, correction to the description of the Millikan oil drop experiment - it actually allows for a measurement of the charge to mass ratio of the electron not just the charge. The mass must be accurately known to calculate the charge from the result of the test.

That is what Feynman was talking about, confirmation bias. It can be subtle and creep up on you.

That is why experiments are independently repeated and discrepancies worked through.

Well, that's what's supposed to happen. And it does, in some areas. But many modern experiments are too expensive or too big to repeat. Nobody will fund a duplicate of CERN where they can re-test the detection of the Higgs, for example; It's just too damned expensive. The next big particle accelerator will be too busy doing cutting edge new research to justify its enormous cost, to even consider taking valuable time out to re-test a result that nobody expects will be falsified.

You can do the oil-drop experiment with a few bucks worth of equipment. So it got repeated a lot. But we are seeing less and less of that - which is particularly worrying in areas like biology, pharmacology, and medicine, where experiments are expensive and theory is necessarily vague. When you design a new molecule that looks like it might have a useful effect in some disease of other, it gets tested until it is approved, and then research moves on. If the initial approval is somehow in error - if the safety of the drug is less than was indicated, for example - it can take a lot of corpses piling up before anyone thinks to repeat the tests. If the effect is less noticeable, the testing may never be repeated. And then there are the drugs that failed to get approval - Some of which might actually be worth having and using, but none of which will be revisited to confirm that they really do casue unwanted side effects as indicated in the original trials.

A lot of what we think of as 'science' doesn't include the level of rigor that ought to be implied by the name.

 

[Peez]

Perhaps related:

The Relativity of Wrong

Peez

 

[steve_bank]

When cold fusion was announced it was refuted within 48hours, globally.

The point is truth outs in the long run science. It is as simple as that, evidenced by the last 200 years.

Not too far back there was Italian experiment to measre the speed of bosons. It was off. Problem was traced to an RF cable that was not properaly calibrated out for time delay.

No one says fallible humans produce infallible science. Science is an evolutionary process evidenced by history. Trial and error is partn o the process.

Someone designing a molecule for medical use will keep it proprietary.

I have a relative who works at Brookhaven. I got to walk part of the RHIC collider ring and through the measurement chamber before it went cryogenic. It is all one of a kind, so it relies on progressive experiential experience on one test bed. Real world science is never a black and white dichotomy.

'..A lot of what we think of as 'science' doesn't include the level of rigor that ought to be implied by the name. ...'

Sounds like you are making noise just to make noise. Ever run complicated experiments on which you have to make a decision of consequence?

 

[skepticalbip]

........snip...........

Sounds like you are making noise just to make noise. Ever run complicated experiments on which you have to make a decision of consequence?

Good point. Many people seem to assume that experiments always yield a digital readout of the final answer. If they did then that insidious problem of creeping confirmation bias would never be a problem. Back to the OP, the Millikan oil drop experiment is not one where a test is done and, poof, there is an answer. It is an extremely tedious experiment that must be done many, many times, each time getting a slightly different conclusion due to conditions and resolution. Results of the serious of tests will be a scattering of "data points" that the researcher must then decide which are relevant and which are outliers before doing the final calculation to determine the point of the experiment, the charge. This is a major point where unintentional confirmation bias creeps up on the experimenter.

 

[steve_bank]

Milliken's work is a good study in science and investigation.

In his time science was a loose association of peers. There were competing ideas to explain electricity. Quantum physics was years away from being established.

One theory was electricity being some kind of fluid. Ohm's Law and basic circuit theory was established, but what current was a mystery. Electricity was a tag for observed phenomena, like a meter deflection.

He was looking forward into the unknown. He had no a priori knowledge. Non of us ever have any a priori knowledge, that makes scince trial and error. To criticize for his niot being perfect is a lack of understanding what it is like.

He worked on his own without funding I believe.

These days simulations of experiments significantly reduces potential experimental errors. The internet provides gloabal peer review before starting an experiment. All he had was a slide rule, paper and pencil, and a very simple test bed. Pretty remarkable.

Similarly the number of decimal places for g has been pushed out over time.

 

[bilby]

When cold fusion was announced it was refuted within 48hours, globally.

The point is truth outs in the long run science. It is as simple as that, evidenced by the last 200 years.

Not too far back there was Italian experiment to measre the speed of bosons. It was off. Problem was traced to an RF cable that was not properaly calibrated out for time delay.

No one says fallible humans produce infallible science. Science is an evolutionary process evidenced by history. Trial and error is partn o the process.

Someone designing a molecule for medical use will keep it proprietary.

I have a relative who works at Brookhaven. I got to walk part of the RHIC collider ring and through the measurement chamber before it went cryogenic. It is all one of a kind, so it relies on progressive experiential experience on one test bed. Real world science is never a black and white dichotomy.

'..A lot of what we think of as 'science' doesn't include the level of rigor that ought to be implied by the name. ...'

Sounds like you are making noise just to make noise. Ever run complicated experiments on which you have to make a decision of consequence?

Sounds like you are annoyed that I don't wholeheartedly agree with your every word, and that you chose to ignore the explanation in my post that led me to that conclusion, in favour of cherry picking one line that pissed you off by contradicting your preferred narrative.

 

[lpetrich]

But many modern experiments are too expensive or too big to repeat. Nobody will fund a duplicate of CERN where they can re-test the detection of the Higgs, for example; It's just too damned expensive. The next big particle accelerator will be too busy doing cutting edge new research to justify its enormous cost, to even consider taking valuable time out to re-test a result that nobody expects will be falsified.

However, the CERN people have a way to avoid building more than one of the LHC. Have more than one experiment team. Different teams look at different beam-collision spots.