Feynman’s advice to W&M student resonates 45 years later (2020)
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Good conversations are so rare. It has been a long time, for me.
(I enjoy abstract conversations about optimistic directions for technology -- although it often involves invoking and talking about -- joking about, if possible -- all of the possible dystopias to avoid along the way. we seem to be dipping our toes into almost all of the latter nowadays, but I tend to believe that doing that also helps expose the nature of the problems more clearly for a wider audience. I also really enjoy bicycle adventures despite rarely being that well prepared for them. recently I spent an hour on a hill "modifying" a front rim to accept a Schraeder valve rather than a Presta valve after suffering a flat and bringing the wrong kind of spare innertube with me; typical)
Speaking of nightmares, my current pet dystopia is solar flare collapse. I'm generally highly, highly optimistic about what science and technology can accomplish, but this is the one thing that makes me doubt the future. It's led me to seriously consider taking on an organized survivalist/prepatory hobby, not only for the slight chance of societal collapse, but it sounds fun to systematize that sort of primitive-style safety net.
What's the model of Serfas pump you mention? That sounds like a good problem to be aware of.
I promise not to throw anyone's food out the window from here on out.
Is it appropriate or helpful to point out any of these issues? The book came out a couple years ago, and I imagine other people who know the author may have pointed them out already. I don't want to make him feel bad (no one likes the bearer of bad news), but if it were me I would want to be told so that future print runs and digital editions could be corrected. (The book is popular and will likely remain relevant for years or even decades.)
Perhaps I should shoot him an email from an anonymous email address?
You could mention that, and ask about the causality problem, why it seems backwards compared to the earlier description, and how you've not researched it yourself and would appreciate clarification. You can also mention that you've noticed some minor typos and ask whether they'd appreciate them for a future printing. I think it's safe to say authors would rather have mistakes not continue to be reprinted.
As I had seen so many versions of it, my chapter was the one on which I could do the less editing around -- I was absolutely tired of it. Lo a behold, the book gets published, I get a physical copy on my hands, and I start seeing typos and small mistakes around. Nothing too serious, but things that I would've fixed.
I know those mistakes are there. Only a handful of people have pointed them out. Those people have not only read the book, the followed it and questioned it. It's nice to be reached out, even if I already know what's wrong.
Only you can answer that question, as none of us here know them! Some people really appreciate it when you point out their mistakes (privately), others will hold a grudge against you for life.
It's just an email, don't overthink it. Don't write a rebuttal essay, just express what you are reading and why it doesn't line up for you and send it along. Maybe there's something you're missing or maybe this is a bit of manuscript that was revised a few times and now doesn't line up perfectly. It's no different than going to a friend and asking if they can make heads or tails from it. They wrote a book to share something they found interesting people asking questions and clarifications is what I would think to be one of the few true rewards.
Thanks HN!
"Arguments from authority carry little weight – authorities have made mistakes in the past. They will do so again in the future. Perhaps a better way to say it is that in science there are no authorities; at most, there are experts."
Reference:the above article
In my thirties, wanting to test out of college algebra, I bought some math software to do drills and refresh my rusty high school math and the software had errors. It was fine for my purposes because I recognized the mistakes, but I was also homeschooling and I told my kids it probably wasn't a good resource for them because it has too many errors, so it wasn't something they should use for math practice. They didn't know enough math to recognize the errors and would have learned wrong.
People make mistakes. This kind of scenario is always a possibility for an outsider with insufficient background knowledge to go "Wait ...that doesn't seem right." and, instead, just goes "But (famous expert) said it, so it must be true."
https://www.arnoldclark.com/newsroom/239-how-to-stay-safe-in...
Otherwise, as he goes on to point out, electrostatic shielding wouldn't be possible. What am I missing?
"I must have assumed it was grounded" doesn't make much sense either, because a charge inside such a conductor has no return path to ground. Either a current will flow outside the enclosed conductor -- in which case where's the return path? -- or it won't.
A thought exercise: consider a van de Graaff generator. In operation, it moves charge from the 'ground' at the base of the belt to the top sphere. It can do this because there's a hole in the top sphere for the belt to pass through. If I enclose the entire generator in an even larger metal sphere, seamless and unbroken, and run it from batteries, can I draw sparks from that sphere? My intuition says 'no,' so it's interesting if that's not the case.
That's what I'm asking. Are you're saying that yes, I can draw a spark from the exterior of a perfect, unbroken, hollow metal sphere containing a van de Graaff generator and some batteries, or otherwise detect that there's any electrostatic activity inside the sphere whatsoever?
(Actually I don't even see how a net charge can be produced inside such an unbroken conductor, thinking about it further. The VDG can only move charge around, it can't create a net imbalance inside the sphere. So the question becomes, what could? I have a feeling that while the corrected version of Feynman's statement is right in principle, it presumes a condition that can't actually exist in nature, like a magnetic monopole.)
I prefer to reason about the simplest cases but since you asked again: if the total charge inside an unbroken ungrounded conducting sphere is zero the field outside it will always be zero, no matter how many VdGs are inside it.
If the conductor is non-grounded then a charge outside the conductor is fully affected by charges inside the conductor but not the position of all the charges (since the divergence of the field through a closed surface will produce a scalar field that varies with distance to the point at which we are measuring the electric potential so the only thing that matters is how far from the closed surface we are (and assuming all charges are enclosed within the closed surface we can represent them as a net charge at the center of the closed conductor).
If the conductor is grounded you are then basically changing the flux with which we can calculate the electrostatic potential at a point outside the sphere (and therefore changing how an external charge will be affected by an internal charge)
> she felt comfortable... ...could question anyone, even Noble Laureates.
The idea that this is explained entirely by class does a disservice to people from more humble backgrounds who are capable of being confident. For example Feynmann himself has a large number of anecdotes about suddenly not caring who he was arguing with because thinking about the problem took over. Los Alamos with all the greatests physcists after Newton present, for example.
Putting class at the centre of everything really isn't vastly better than pretending it has no relevance and does not exist. The thing that should interest us more is where are the modest background geniuses coming from now? Is class distinction getting more important and becoming a stronger barrier now than in the 30s and 40s or from this story the 70s. US tuition fees and student debt would suggest it is worth looking at.
https://www.youtube.com/watch?v=Dkv0KCR3Yiw
He was the child of poor Jewish immigrants.
I've heard of "non-apologies," which are sneaky ways of sounding like one is taking responsibility and apologizing without actually apologizing or taking responsibility.
But this is the opposite-- Fenyman takes zero responsibility for having led the student astray, and in fact chastises the reader for appealing to his own authority. At the same time, he gives evidence for why he should not be trusted as an authority-- he goofed and doesn't even know why!
It's like a variation of an old one-liner comedy insult, something like: "I got news for you, we could both do better!"
Anyhow, I like it.
Your comment is very hilarious since Gauss's law is high-school physics. So Feynman would have clearly known how he goofed up.
Like if I wrote in an article or book chapter that 2 + 3 = 7. I’d know what the error was when it was pointed out to me. But I wouldn’t be able to imagine how in the world I made such an elementary goof.
And why would that make you less of an authority? I was replying to a comment that suggested that Feynman ought to be not trusted as an authority because he goofed. Please try to follow the discussion in the thread.
No one has the resources to verify the whole of science through first-hand experience so at some point you have no choice but to trust someone.
You don't have to "believe" the axioms. You can test them, by testing whether the experimental predictions derived from them are confirmed or not.
Because experiments show that it's correct.
> No one has the resources to verify the whole of science through first-hand experience
Courses in science commonly include actual experiments, either done by the professor while students watch, or done by the students themselves in labs, precisely to give the students first-hand experience in the scientific phenomena being studied in the course.
> at some point you have no choice but to trust someone
You may have to trust other people for first-hand observations of things you didn't observe yourself. But that isn't what's involved here. Here the student had a theoretical law whose consequences she was perfectly capable of working out for herself. She did not have to trust anyone for that.
In this particular case, the student even saw the problem with Feynman's statement: her letter says, in reference to the statement in Feynman's book that turned out to be wrong: "This was confusing, as it seemed to contradict all your previous statements." So why did she base her exam answer on the statement she found "confusing"? She should have thought it through for herself.
Another relevant details is that "the class was a survey course for non-majors".
>She also clearly refused to believe her professor when he explained the problem to her.
There's nothing in the letter to support this conclusion. But in any case, you can't coherently criticize the student both for believing Feynman and for not believing her professor! I thought the point was that she wasn't supposed to 'believe' anyone.
And yes, of course the student was hoping that Feynman might have turned out to be right after all so that she could get some extra points on the test. So what?
And he answered that question.
> I thought the point was that she wasn't supposed to 'believe' anyone.
I am presuming that her professor actually showed her why she was wrong, instead of asking her to take his word for it.
> And yes, of course the student was hoping that Feynman might have turned out to be right after all so that she could get some extra points on the test. So what?
You don't get it. Gauss's law is a very very elementary law (usually taught in high school). Her professor would have most definitely explained why he took off points from her exam. There are two explanations now as to why she included that PS: i) she didn't understand her professor's explanation, and hence also did not understand Gauss's law properly, ii) she was grade grubbing. I cannot sympathize with her for (i) since she most definitely did not make an effort to understand her professor's simple argument, yet she found the time to write a letter to Feynman. Also, W&M is a large research university with multiple physics professors and graduate students and it's unlikely that no one would have been able to help her with this. So she clearly didn't try hard enough to understand Gauss's law and that's not Feynman's fault. And I really cannot sympathize with her if it's case (ii).
b) William and Mary, although close to Thomas Jefferson lab, is not an R1
b) Also doesn't make any difference. I'm familiar enough with W&M to know that (i) it has a full-fledged graduate program and (ii) professors there collaborate extensively with JLab in both theory and experiment, though I admit that I don't know if that was the case when this student wrote the letter.
Even the beginner doesn't have to "trust" that calculus works. He can verify for himself that using calculus to manipulate equations in the theory yields predictions which are confirmed by experiment.
The main area where I see that "trust" would be required in science is reporting of raw data directly obtained from experiments that other people run. Yes, everyone else has to trust that the person who is reporting that data actually ran the experiment they claim to have run and recorded that exact data from that experiment in its entirety--that they didn't make up the data, or massage it, or cherry pick only certain runs, etc. That is why, when scientists are found to have violated this trust, the penalties are typically severe.
Other than that, though, you don't have to "trust" anything in science blindly. Whether a particular set of data is consistent with a particular set of theoretical predictions is something that can be verified independently. And since theoretical predictions are just mathematical derivations from certain stated axioms, those can also be verified independently. So no one ever has to just take someone else's word about those things.
The US educational system seems to regard some of the foundational elements of STEM will enormous trepidation (I've known US high school students headed for STEM majors at quality universities who haven't studied calculus for more than a year (typically just covering differentiation, not integration)). Combined with it's greater breadth of educational goals, both in grade school and even for a bachelors, it's not really surprising that there will be students (in the US at least) who begin college level physics without fully understanding the tools (or history) of the subject.
You always have to stop somewhere. Any given one of your assumptions may be verifiable in principle, but you won’t have the time and wherewithal to verify all of them. Science as it’s actually practiced is a huge pyramid of trust.
The verification issue comes about when you need to run the experiments yourself to prove that your equations don't just match with fudged data.
You can pretty much prove that calculus works from a purely logical basis (I might be using incorrect terminology here but you get the point, pure math is self-proving.).
Right, but it’s pretty clear from your use of terminology here that you personally haven’t studied the foundations of calculus deeply. Which is 100% fine. You understand roughly why it works and you trust that specialists have checked it out more thoroughly.
A lot of people on this thread keep pointing out that various things can be verified. But they are saying this precisely because they themselves have not verified the things in question and yet trust that it is possible to do so. The point is that this is perfectly reasonable in most contexts. You do not have to take on the burden of proving for yourself every mathematical theorem that you make use of.
There are shades between full formal verification of literally everything and then "trust the elders". You can know a little bit about a lot and use that as a sort of statistical verification because you're basically running a monte carlo sim to find holes in the logic, if you find no holes then you can reasonably assume that the rest is true and that's not based on trust.
It's a bit like having a 500-dimensional jigsaw puzzle, once you show that most of the pieces fit together the other ones have nowhere to go any more except to fit.
This particular incident had nothing to do with the validity of Gauss's law, which is nothing but a restatement of Coulomb's law in electrostatics, and something that has been extensively verified in experiments. Feynman's presentation of Gauss's law is crystal clear. The issue in question was an application of Gauss's law. Feynman likely goofed up (like most of us do) because he didn't think twice and went by his intuition. And he was absolutely right to criticize the student -- saying that something is written in famous book X written by famous author Y is completely irrelevant in science if you cannot make a good argument for why it is right. This is different from many social "sciences" where people often make such claims.
I think Feynman was getting on a favorite hobby horse about not trusting authority and reading the letter a little uncharitably.
Sure he did. He said he goofed.
> and in fact chastises the reader for appealing to his own authority
And he's right. In science, there is no such thing as appeal to authority. If the student thought her answer was right, she should have produced an argument for why it was right--and of course she couldn't because her answer was wrong. She should not have appealed to an authority.