Ohhhh, scratch my above comment. I thought Rob deleted NA's questionnaire, but it was Tech Droid's. Good luck to the three running!

@ZeroTheHero not to mention the 40/40 candidates score. I appreciate the support and an disappointed as well, but my actions are what led to the suspension (even f there was a level of misreading, it's my fault for not being clear about who the comment was intended) so I don't think we can necessarily blame SE CM for much

It seems strange that the system actually shows the nomination before CMs have a chance to deny it

Probably takes some additional coding that may not be worth it, given how infrequently elections are and how unlikely someone recently suspended would nominate themselves

@KyleKanos That's exactly it. There was some discussion about it in the mods-only chat room today.

Woot woot, I caused people to talk about me!

@rob I suppose I'm not the first who tried though, right?

@KyleKanos No, I think pretty much every election somebody tries. I know in particular of a couple during the last Physics election and I've heard of them on other sites.

The issue is that SE want to be able to make exceptions so that folks who've had baseless or accidental suspensions can run.

If they automated the logic of "can't suspend with recent suspensions," the exception-handling code for candidates who should be allowed to run anyway would be complicated.

At least that's how it was explained to me.

Given my POV, I'd say I was baselessly suspended. A Warning I almost surely deserved. But I'm not in power to make such distinction

You would think withholding nomination visibility from regular users while processing would be an reasonable feature if this happens in most elections :S

There's definitely a script that runs to see if you've been suspended to pop up the warning, there probably could be a "wait until response from SE" period, much like how there's a block to prevent you from answering protected questions

I'm thinking even just hiding it for regular users, as if it were similar to a deleted post, until a CM gives it the go-ahead, or similar to a pending edit "This nomination requires approval from community moderators, and will not be visible unless approved."

I thought about writing a Meta post about my removal, but I suspect the interested parties have been in chat to see it, so it might not be needed.

@JMac A good question for the Mother Meta would be what technical challenges stand in the way of this, and what fraction of network-wide elections have a user that has to be removed.

@KyleKanos I'd like to clarify this, but I'd rather not do it in chat --- if only because my attention is divided and I might have to suddenly disappear.

@rob Email is fine, if you want more time to respond & don't want to here.

@KyleKanos Whatever the decision, how it was implemented is absolutely upsetting. On a separate note, it would be good to have a meta post where are the scattered bits and pieces are collected.

@rob I'm going to write a question in the main meta for a status request to treat them similar to pending edits in these cases, to gauge what SE staff actually thinks about the feasibility/value

@JMac That's a good idea --- not least because it gives a sense of the size of the coding project involved.

@rob Yeah, exactly. If they've thought about it and just consider it too much expense, cool; but I haven't seen it asked so it seems worth a shot

A kind of a stupid change that would have made a difference in this case: if the nomination period had ended on a Tuesday instead of a Monday, then this drama wouldn't have played out in the last hours of the nomination period.

@ACuriousMind I don’t feel so lonely now.

Yeah, this was kinda a perfect storm of circumstances, Kyle's nomination on a weekend and the election ending on a monday just made the problem very obvious

Hi. I was thinking if we consider a particle on a ring then the size of the Hilbert space seems countably infinite if I think in terms of the eigen spectrum of the momentum operator but uncountably infinite if I think in terms of the eigen spectrum of the position operator. So, the kind of infinity of the size of the Hilbert space depends on the basis we choose to express it?

I see how the uncountably infinite version is bounded while the countably infinite version is not--and it basically represents that the Fourier modes of the former domain would be discrete and unbounded. But when I want to interpret it as the nature of the size of the Hilbert space, it "looks" awkward.

Is there a length or time that is so big that it breaks down our understanding of physics as we know it? (Like the opposite of the Planck length)

@AdrienDaBoss There was a Scientific American article about twenty years ago, from right after the discovery that the expansion of the Universe was accelerating, about what the very distant future would look like in such a universe. I remember on the logarithmic timeline, around 10^{100} years, the phrase "quantum tunneling liquifies matter."

@KyleKanos encourage you to write it & think will likely upvote it for 1, but the "angle" could be tricky. am personally interested in how it relates to the generally opaque/ sometimes heavy handed/ near-arbitrary suspension policy and how it can backfire aka mgt shooting self in the foot, for which there seems to be little-to-no existing discussion in meta, although theres very substantial bkg in the chat transcript. there is some precedent, 0celo7 on his case in meta has ~20 votes.

@rob Might be thinking of Dyson's Time without end paper. But it considers a ballistic universe not an accelerating one.

meta.stackexchange.com/questions/327495/… let me know if anyone sees room for improvement

@JMac nominations from suspended users should probably be more along the lines of "nominations from users who were suspended within one year of the election"

@KyleKanos changed to "previously suspended" because I'm lazy and it made my point, thanks

Roger Roger

@JMac not sure I would discuss “game of chicken”. Maybe “nominations were slow to come in”.

I don’t see as “playing chicken” someone who will reflect on the commitment and who might want to ask questions and/or generally stay tuned to the chat discussions.

why is it indicated under my chat avatar that my rep. is 23.7k whereas my actual user rep is closer to 21.5k?

@KyleKanos concept of a "baseless suspension" cannot make much sense unless there is some kind of semi detailed written policy but both mods + SE mgt resist that for misc reasons. "baseless suspension" might mean a mod acting in a completely arbitrary or clearcut unethical way wrt suspensions, but think thats rare & provocation can almost always be identified. think much more relevant issue everyone is missing is about commensurate response eg candidacy not rejected due to 1 day suspension etc

@Rishi I suspect that we are doing the election so that it will be clear that the users appointed them. Though like you I have little doubt of the outcome at this point.

NewAlexandria for moderator

Jesus I'm tired

I found it amazing how there are many SE elections underway with weird things happening, and then looking back, 18 days later, we Australia are going to have the most important election ever that will decide a lot of things

also with a lot of weird things expected to happen including small parties are going to win alot

If this world is a computer, it seems within these few months, there is a massive overload of glitches

@Rishi We were prepared: chemistry.meta.stackexchange.com/q/4402/7951

Is there a reason why it seems multiple SE elections are taking place this month?

usually its only one active roughly per month

ah that might explain why

well, I think the message is not explicit enough. He mentioned how the workload is less and how chemistry has less drama than other sites, but I don't think people will spontaneously made the connection about the situation in physics

This display is hooked up to an arduino. How is the display controlled when there are very few wires coming out of the display?

I mean, the arduino should be able to switch off an on every "pixel" of the display, but how does it do it when there are like 8 wires coming out only.

@NovaliumCompany your TV can display a picture with only one wire (the aerial lead)

oh.

also my monitor :P

right

Does the montior receive like RF cars do signals 1 and 0?

and refresh it like every x seconds?

It will probably use some form of serial protocol i.e. every frame is transmitted as a linear sequence of bits.

At least two of those wires will be for power, so that only leaves a maximum of six wires for the data.

Yep, for example every second the display receives 1001010100101001010101010... and updates the montior :P?

What about color then?

So like every display has a pre-established languages it should be talked to in order for it to work?

@NovaliumCompany colour images are made up from three monochrome images i.e. a red image, a green image and a blue image. So a frame of colour is transmitted by transmitting the three monochrome images.

@NovaliumCompany there are standards for image transmission that the monitors will conform to. For example HDMI.

But again, this whole sequence of ones and zeros are send through a cable and the display then interprets it?

@NovaliumCompany yes

The display has an already established language and the arduino library for example knows that language and how to convert the code into the language into the zeros and ones?

But why are there more than 2 wires then?

@NovaliumCompany don't know

Wow, this is the first time I catch you not knowing something. :D

@NovaliumCompany :-)

@NovaliumCompany A quick Googling suggests that the e-paper module uses the SPI interface

greetings

How come doesn't glue "freeze up" in it's package?

I mean, I have a glue that's in a liquid form, when I expose it outside of it's package, it hardens. Why doesn't it harden in the package?

@NovaliumCompany it does

if you ever had some glue for a few years in its bottle it will crystalize into a delightful mass

I'm guessing the reason it's so slow is just that it needs to react with air or something?

I mean, for a start

what glue do you mean?

Different glues may have different reactions

Superglue needs oxygen before it can start the polymerisation, for example

apparently superglue (cyanoacrylate) reacts to humidity

ok I misremembered, yeah it was humidity that facilitate the polymerisation

the water help the monomers to link together by chain polymerisation

Yes, water sets cyanoacrylate glue, more specifically, the hydroxide ion. en.wikipedia.org/wiki/Cyanoacrylate#Properties

Hi. Can some moderator please see if this question is still in the review queue or is it still closed even after the review?

from what principle do the coefficients of an operator product expansion come?

@NovaliumCompany see also chemistry.stackexchange.com/q/32784/7951

@ViniciusACP You can see yourself: physics.stackexchange.com/posts/470034/timeline

Thanks @Loong. So, what can I do about it? I know I can't simply delete and repost, so any suggestions?

(I've already fixed the question, I believe)

@JMac because it looks cooool

Hello

How to start a poll here?

XD Can it be done?

@AbhasKumarSinha I think most people would agree it doesn't really look cool to have the same letters repeated filling up a bunch of the chat...

@ViniciusACP If you think the question has been substantially improved after its close review, you can make a meta post pointing it out and asking if the community agrees. But if the community's response to your meta post is that your question stays closed, it may just be that your question isn't a good fit for our community.

But that might be a bias because I just got agitated by reading today's international political news

So I should go back and read some science

@AbhasKumarSinha Can you stop spamming

@rob In my view, the question is ok now. In relation to being substantially improved I have my doubts, since I only removed part of the questions from the post to narrow its scope. But I believe its not too broad anymore.

@ViniciusACP Complex current & voltage is a pretty broad topic. en.wikipedia.org/wiki/… I can't currently see your question, but I vaguely remember it. If you can ask a single focused question about a specific use of complex numbers in circuit analysis that should be ok, but a general question asking how complex current & voltage works is simply too broad.

@AbhasKumarSinha No, it makes you look like a child.

@PM2Ring my question isn't about complex current and voltage. Its about the meaning of complex capacitance and inductance.

I think the Wikipedia - operator product expansion does say what principles an operator product expansion is based on based on my impression of coming crossing it more than once.

@AbhasKumarSinha The SE chat system doesn't provide a mechanism for polls, but there are ways to run polls. I suppose if you have a good poll proposal the ROs may consider it. But frankly, I don't like your chances.

I think there is no generic principle to be invoked to get the structure constants in a Lie algebra; one just needs to calculate it case by case, but what about operator product expansions?

@PM2Ring L(jw) = L_real + j* L_imaginary and C(jw) = C_real + j*C_imaginary. (And, althought related, its not about complex impedance too)

I didn't find much information about it. I've looked in several places in the web and several books too.

I think some operators can be just Lie algebra, so maybe their operator product expansion may be based on structure constants in Lie algebra.

@KyleKanos Are you solving stochastic (P/O)DEs in your current work? If so... I am trying to solve a PDE that is something like d/dt Q = R(Q) + F(Q) where R is deterministic and F is stochastic, both on a 1D line in space. R is continuous in time, F is not continuous in time. Basically F() will mix up the 1D line at instants in time based on some pdfs.

Any suggestions on resources for how to tackle the problem would be helpful. I don't have the terminology to know what to look for really. We've always (as in the community for 30 years) just done it as a Monte Carlo simulation

I don't actually work on SDEs myself, but you can look into Euler Maruyama method for solving SDEs numerically

There's also the Milstein method

@tpg2114 Wilkie's Numerical Methods for Stochastic Differential Equations (arxiv:0407039) discusses Runge-Kutta methods as well.

Yeah Captain Obvious who just want to find a way to evade answering the question

Formulating questions so that it is impossible for any person of any belief system to evade the question except by saying "i don't know" is one of the hardest art to master

Exposure to politicians does really help me on improving that kind of project as politicians are extremely skillful at evading questions

Fun fact: When it came to formulating questions, the use of the word "everything" and "something" both allow a way to evade the question:

1. If one said everything and the reality is not everything, those people can evade the question by using the excuse that the premise is wrong and hence the question does not make sense

2. Eise if one said something or not everything, those people can also evade the question by giving a trivial answer

I have not find a way to patch this hole yet in Question Theory, but I do know that people who take these routes do not pay attention to the question and have no intention to answer, thus their comments are thus dismissed as irrelevant

Well at least it's a comment and not an answer. Though with an answer we could at least DV it.

yeah

@Secret I see my2cts' point. OTOH, his logic is spurious. Eg, pretty much everyone isn't the president of the USA, but that doesn't imply that what the president of the USA says or does is unimportant.

meta.stackexchange.com/questions/327495/… ... already status declined, but JNat's response feels like it totally missed the point, and at very least didn't even remotely address if it was feasible

@JMac interesting that they claim a suspended user is "ineligible" despite the fact that the language in the pop up window does not say they're ineligible & strongly implies quite the opposite

@PM2Ring hehehe.... No problem!

@Secret Sorry! :P

Where can I read on what happens when partially polarized light (eg. reflection of a glass) hits another sheet of glass?

Uh. I didn't phrase it well. I know what happens, but I need to understand how to calculate the reflected intensity after the 2nd glass.

Reviewers: please have a look at this answer and consider whether the edits after it was deleted make it acceptable. Vote or flag accordingly. Thanks!

@KyleKanos The old fights are over. If you had nominated, you had probably won. You as a mod probably wouldn't make the site worser. I probably hadn't voted for you, but hadn't voted also against you.

@Fermiparadox I think the effects are practically linear, so a simple 2x2 matrix multiplication says the result.

@peterh Could you point me at somewhere I can read more about it?

@Fermiparadox No :-( But I don't think that asking this question would result a closure because the lack of initial research.

@Rishi I would click "recommend deletion" and ask the OP for clarification in a comment.

@Rishi Yeah. It's saying that in vector notation, "r" is actually r in the i direction, and 0 in the j direction, initially; but over time those will change, even if the length of r is constant. It's not the best answer, but I get what they are trying to say

@peterh lol, thanks for the ringing endorsement.

I'm certainly a better option than the 3/40 candidate we do have, but who knows how compared to tpg & Chris

@KyleKanos The 3/40 is imho a blind try. A candidate with low reviewing activity but high physics skills is imho not a problem. I think the site requires to improve its image in professional circles.

@peterh I disagree: mod position is more about reviewing flags than being good at physics. I'd wager that a non-physicist could do just as good a job at moderating than a physicist.

@KyleKanos Spot on. The flags that actually require subject expertise to handle are rather rare.

However, I'd argue that moderators should have an understanding of what this community values, which is most easily demonstrated by them having a high reputation, but it's certainly not necessary.

@KyleKanos How is the PSE known in professional circles? I suspect, it is known, but it is considered as a primarily enthusiast site. Attracting many physicists would lead to a huge improvement.

Emilio was rather accurate when he said this in the election room, I think:

Honestly, I don't care how PSE is viewed by "professionals".

As long as the members view it with some level of esteem, I'm okay with just that

But note also knzhou relating his more positive experiences in the same discussion

@peterh The moderator would mostly be enforcing site and network policies; understanding physics has very little to do with that. Having a user who isn't familiar with the general atmosphere, let alone the rules, doesn't seem that beneficial, and would probably be pretty stressful for the mod

Presumably, though, such an "outsider" nominee would require on the job training, as it were, and could gain a sense of the community in relativity short time through that. But there's a lot of history on PSE that could prevent that (e.g., the dreaded homework policy)

@peterh I disagree. I expect that the question would attract downvotes & close votes because of the lack of prior research.

@PM2Ring Doing that would be bad. I think the site is not so bad. I remember my most top-voted question (https://physics.stackexchange.com/q/143166/32426), it was not closed and received very well, however anybody fighted for the survival of his question, can see, that most of its content serves only the goal to avoid its closure.

@Fermiparadox Do you just not know about the Fresnel equations or is there a reason they don't give the right result here?

@JMac Most mods tries to let the closure decisions to the community. Iron-fist actions are rare. But they have an above average effect to the site policies, and a significant freedom in applying them to induvidual cases. I think a mod being very good in physics, but not very experienced in handling flags, could create sometimes problems, but would shift the site to be more liked by other professionals.

@peterh I fundamentally disagree then. I think having moderators who are experienced in site policies and procedure shows much more professionalism than moderators who have little experience moderating, even if their physics experience is more limited. The notoriety of the moderators seems like an unlikely reason to change how much we draw professionals in. Moderators who are consistent, fair, and knowledgeable about site policies seems like a much more reliable way to attract and keep

professionals

@JMac Ok. I created a SEDE query: data.stackexchange.com/stackoverflow/query/1040366 It shows the percentage of the questions of the users, by the year of the posts and by their (current) reputation. It is not very well visible, but I think it shows that the high-rep users tend to ask lesser and lesser questions, as the years are going. I think, it is not a good phenomenon.

@peterh If you're posting some of the most advanced answers on the site, then what's the chance the site can answer your questions?

From the beginning I've had to bounty the majority of my questions to get a reply.

I bet most of @ACuriousMind's serious questions are still unanswered.

This is a consistent phenomenon that has existed basically since the inception of the site, cf. physics.meta.stackexchange.com/q/4571/50583.

Interestingly enough, different experts offer rather different explanations for their lack of questions

@peterh Completely irrelevant to what I was talking about as far as I can tell. The situation with experienced users and a lack of questions could have any number of explanations. I don't see what any of them have to do with getting moderators who aren't as familiar with the moderation of this site

@knzhou my four most recent questions have received a grand total of one answer that opens with an apology that it's just offering a hint :P

And honestly, when I have a question related to my research, I go to papers, or my advisor, or my office-mates. Phys.SE is pretty far down on the priority list.

I literally haven't asked a single question on PSE. I have nothing good to ask, but it doesn't mean I can't contribute

@knzhou I think most of physics research is so specialized that a large site such as this is a really inefficient way of communication for the rather small amount of experts that actually can engage with the technical details of such research

They have conferences for that!

Indeed

@ACuriousMind I wonder how the number of research grade mathematicians and the number of theoretical physicists compare. I wonder if the former is a significantly larger community and that's why Math Overflow works.

@JohnRennie Both MO's much narrower scope ("nothing below graduate level")and its history - being explicitly started by professional mathematicians for professional mathematicians, outside of the SE network - are the key factors here, I think.

Hey guys, I'm making a DIY plastic water pump and I was wondering does it matter how many propellers I have.

For example this one has 5, I have 1, does it affect the performance?

@NovaliumCompany Yes.

How?

And also why is the input pipe exactly at the center top?

depends on all the differences. going from a multi-blade propeller to a single blade propeller will definitely change the behavior, because that is what does the pumping

So I should add more propellers?

Instead of a single large one?

@NovaliumCompany seems like a centrifugal pump; which makes me even more skeptical that a single propeller (technically impeller) would work

Would more impellers make it pump faster and stronger or?

What exactly is the difference

The DC motor is spinning so fast that I don't think it matters that much?

Also are DC motors waterproof :P?

oh I don't know exactly. I could have taken a course specifically about pumps, but didn't. I should probably still know this, but I don't really know the relationships well. I just knew the easy answer that 1 blade vs 5 blades will definitely be different

oks

@peterh There is a well known, private, technical university near my new place of employment, and I've been adjucting there in the evenings this semester.

Some of the faculty there penetrated my secret identity, and they indicated that they consider Physics Stack Exchange a prime resource for their graduate students, and offered thanks to all those who keep it that way.

These are people with considerable experience with the resources that were available before Stack Exchange.

@NovaliumCompany Presumably so that it goes through as evenly between the blades as possible. It uses inertia and centrifugal force to push the fluid to the outside of the casing. If you aim right at the middle of the impeller, then it spreads out equally in the radial direction

@KyleKanos I think the moderation team needs some people who are familiar with the field at a high level. But I agree that most of the work is not at all technical in nature and an amateur or beginner could be a good mod.

@dmckee Thanks, it is good to know. But, I think, as the level of experience grows, so will be the questions of the potential PSE user harder and harder. And so will be it more important to get answers to their questions from professionals on the same field. However, also the skill grows to find the answers for themselves. I think, PSE should show for the top-level researchers, teachers of Universities and other hardcore people, that here they can get an answer more quickly and easier, than

@dmckee finding it by own research.

@dmckee My experience with other SE sites that answerers are targeting mainly the newbies, because their questions are easier answerable and they lead to quick rep growth. Asking a really hardcore question (really hardcore starts what can be answered by lesser than $\approx$ 100 people on the world) will result mostly crap answers or no answers, and not even bounties can help here.

@peterh But how do we show that if it's not necessarily true? I don't see how we could demonstrate that this is a resource to get answers to high level questions quickly and easily compared to self-research; when generally the high level questions aren't answered quickly or easily, but generally require you to put up bounties, be patient, and hope that someone knows how to and is willing to solve it

@JMac I think we can't show it, because it is not true. First it should be made true, then it should be shown.

@JMac Currently, if a physicist answers the question of another physicist, only a part of the other physicists will understand the answe. Thus he will get far lesser upvotes, than he could get for a simple answer to an enthusiast level question, extended with some pictures.

@peterh So how do you propose we actually resolve that?

@JMac However, I think the system actually contains the information, how hard a question is it. And it also contains the information, what is the actual skill level of most users. It doesn't even require private data (for example, induvidual votes). We only don't use it.

@JMac If User1 could answer User2's question with a positive score, then we can think that User2 might have a higher skill than User1. Do you know the elo rating system in the Chess?

@JMac If the database has a positively scored answer of user2 to the question of user1, we could create a potential between them. Roughly, a potential of $P(\rm{user1},\rm{user2})=\frac{1}{1+e^{-x}}$.

@JMac After that, the potential of the whole Q/A database should be minimized by gradient walking. The SEDE is incapable to do that, but it would be easy in any procedural language.

@JMac Of course a fixed parameter-less model would be preferred, and some boundary conditions should be also injected in the system. The result would be, that we would have a good estimation, what is the actual skill level of the induvidual users. Not only their activity.

@JMac Next step would be to increase the strength of the votes of the highly skilled users.

... I don't follow how that solves the issue of getting these contributions.

@JMac If you have a way to find the highly skilled users, you can also prefer them on various ways. For example, physicists could have an option to see only the posts of other physicists. Essentially, they would exist on a sub-site, which is a closed circle only from physicists. Another option would be to give a higher strength to their votes.

@peterh That doesn't seem like it would help. Either splitting up the community, or making it unfairly biased so that getting points gets you more points

@JMac No. Exactly no. Because this "skill level", which would be a different point than the reputation, could not be affected by writing more posts. More exactly, it would be, but only logarithmically. Just like if you play more chess game, your elo rating won't grow. It will only grow, if you win stronger opponents.

@JMac The "skill level" would only grow, if you answer questions of others with high skill level.

Physics is not a competition.

@peterh If User1 could answer User2's question with a positive score, then we can think that User2 might have a higher skill than User1 Sorry? I think if User1 can answer User2's question then User1 has a higher skill level than User2. And that really only applies to the topic of that question. In another topic, the situation may be reversed.

@PM2Ring Sorry, I wrote badly. Yes, I wanted to write what you estimated.

@ACuriousMind Tell that to the Bernoullis. :D

@PM2Ring They've merged into one super-Bernoulli in most people's minds, seems like a booby prize ;P

@ACuriousMind I was about to say, "it's all Bernoulli to me!"

@PM2Ring Yes, it might be also topic-dependent. That could be watched in tags.

@ACuriousMind And how about the reputation system, it is not enough competitive? And the rep system prefers much more quantity over quality.

@peterh Making the system even more competitive by introducing additional privileges - especially ones related to voting, and hence reputation itself - does not seem like an improvement to me.

Also, let's be realistic here: If you have any hope that SE will change the most fundamental aspect of their sites, that'll never happen. The reputation system as it is now is what these sites are built on and it will be that way until the servers one day go offline.

@ACuriousMind That I know, it is more a thought experiment to me. But I think it is an interesting thought experiment.

@peterh I would argue that the rep system actually is a pretty decent measure of the quality x quantity of answers provided. Someone contributing a lot of low quality responses probably wont do much better than someone answering questions well when they feel they have a good answer

@JMac "skill level" would be roughly a quality x log(quantity)

@ACuriousMind As far I know, in the academia, there is also some trickery about the different measurements of the publications. Impact factor and similars. I think, it is quite competitive for professional researchers.

@JMac think youre asking the right questions. suggest pro physicists (not nec those on the site, or even specifically those that arent) be asked about their attitudes on the site & how it could be more engaging. wonder if more could be done with creative uses of chat. maybe the pro physics community is smaller than the math community hence success of MO but not physics overflow. the general word for all this is outreach which seems is not often given attn...

@JMac I think an answer to JohnRennie's question worths much more than an answer to the question of a rep1 user. At least in the "expected value" of the worth.

@ACuriousMind True enough. I used to vaguely remember which Bernoulli did what, back when I was reading the history of mathematics & science, but that was several decades ago. And before my long-term memory became dependent on Wikipedia. ;) m.xkcd.com/903

@peterh I don't see how that helps either. Someone who contributes very well but rarely is probably just as useful as someone who contributes excessively, but with less effort in their posts, one person isn't helping as many people, but perhaps helps them more, while the other person helps more people, but maybe less completely. Rep measures that, I don't see why a log(quantity) metric added in would benefit us.

@peterh Your point being that because real life is competitive and many have an obsession with numbers pretending to measure someone's worth, this site must be like that, too?

@peterh Yes, one would expect on average that John Rennie would provide a better answer than a 1 rep user. He also has significantly more rep, so that is statistically what you would expect in this system. How does adding a new metric for site participation change this?

@ACuriousMind Prefering some people doesn't need to mean the opression of the others. I think the goal should be, that also professionals should get on the site what they want, and also the enthusiast-level people.

Reputation is sort-of competitive, but gamifying it works also because it does not stand for anything concrete. You can get it from 1000 okay-ish answers or from 3 really great ones, it does not pretend to measure that. It's fun to compete around because it is no implicit judgement of character if someone doesn't have that much rep. I would refuse to participate in a site that openly ranked the "skill" of its users, regardless of how much sense their determination of it makes. That's not fun.

@ACuriousMind I think, professionals want a more professional community. Enthusiast-level users want more freedom in asking questions. Putting some option for them to separate, could lead to a win-win situation.

Now it really sounds to me as if all you actually want is a mirror of the MO/math or TCS/CS split, but everywhere.

@ACuriousMind Yes, but without splitting the site. And it would be only an option.

Seems to be a distinction without a difference if you're effectively trying to create a two-class system of "skilled" and "non-skilled" users that don't really interact.

One major difference between modern researchers in mathematics & physics is that a solo mathematician can do cutting edge work, whereas in physics that's almost impossible if you aren't part of a team. Maths papers still have 1 or a small number of authors. Physics papers do not.

@PM2Ring Probably has something to do with the upfront costs of a physics lab compared to a ... math lab?

@ACuriousMind No, the "skill level" would be a continuous result, just like the rep or the elo rating. And it can be calculated by using only the public, available data.

@JMac don't underestimate the chalk costs :P

also, topologists need a steady supply of donuts

@ACuriousMind Btw, the two-class system exists. Low-rep people mostly ask, high-rep people mostly answers. And, what is imho quite bad, high-rep people tend to ask even lesser and lesser with the years. Sede query. Y coordinate is the percentage of questions posted by the given rep group in the given year.

@JMac Certainly. Few individuals in the world could even afford to pay the power bill at CERN. :) But also, it's not often possible to divide a maths problem up so that members of a team can work usefully on the different parts, unless you have lots of special cases to deal with, like the 4 colour map theorem, or the classification of finite groups.

@peterh Yes, you've already said that two hours ago. Nobody disputes that that's a fact.

But it's not so bad. The high-rep users are happy to answer questions, and there's a steady stream of new users (and the occasional high-rep exception to the rule) asking questions. Where's the problem?

@PM2Ring I think this is a non-negligible cultural aspect to this. I mean: the rate of publications are different, and thus the expectations about the rates of publications are also different.

@ACuriousMind I think there are two goals what could make this site great: 1) anybody is coming with any physics problem, he will get a good answer 2) hardcore, top-level researchers could share their knowledge with each other. | These goals are contradicting, the site politics is determined by mainly by a balance between them.

I've never asked a question on Physics or Mathematics, but I've learned a lot from reading the answers to existing questions. The same goes for SO, since whenever I have a coding question I can almost always find the info I need in existing answers. Although I do sometimes ask minor questions about a few software libraries in chat.

I might ask a Physics question one day, if I can figure out how to write it in such a way that it won't get closed as homework-like. ;)

@ACuriousMind I think a knowledge share between highly skilled professionals is few, and with the decreasing ratio of their questions, it will be even lesser with time.

Please guys... don't take the fun out of this site.

@PM2Ring Yeah, I've heard everyone on that site is terrible about homework questions

@peterh You still haven't explained what the problem is. Highly skilled professionals are smart people, they'll manage not being able to use an SE site as their best medium of communication.

I get it, you want a different site. What's unclear is why you seem to need everyone else to want it, too.

@ACuriousMind But if an SE site would be the best medium for their communication, wouldn't it be great?

... and in fact one can legitimately ask why you'd want to share your research ideas on a public website given the competitive nature of physics research...

@ACuriousMind No-no. I don't think that the SE would ever change. It is not really more like a thought experiment for me. Maybe I will make this little calculation, just to know, who are the really most hardcore guys. And I will be also sad a little bit, why the site won't help them more to find each other.

@ZeroTheHero That sounds reasonable. Also, in science it's possible (although not exactly always encouraged) to publish the results of research that culminated in a null result. In mathematics, that's almost impossible. I guess you can say "I tried proving the Riemann hypothesis by doing X, Y & Z, but it didn't pan out".

@PM2Ring The skill of outstanding researchers is to transform a null result into something positive. I was just in a meeting yesterday with a colleague and his student, trying to convince the student there is a difference between a negative result and a failed experiment.

There is a difference and an important distinction between the two.

anyways there no doubt in my mind there is an over abundance of “please-do-my-work” questions. Physics is more “process-driven” than other disciplines; the emphasis is less on the answer and more on the principles behind the answer. It does not mean answers are unimportant, but physicists emphasize “getting the physics right” over other aspects.

In this way PhysicsSE is unlike math or CS, where finding the correct substitution or the correct function can be a matter of experience, or just a matter of knowing the right trick. The (considerable, maybe impossible) challenge is to properly encourage new users to take their time, use the search feature, and do some lurking before posting.

@JMac My turn to write on Mother Meta.

@ZeroTheHero For sure! There's value in saying "That definitely does not work, don't bother going down that path again". OTOH, there's not much point publishing when all you can say is "our results are inconclusive, because our lab technique sucks, or we can't afford equipment that doesn't keep breaking down".

@PM2Ring dmckee just recently talked about how a large part of student labs is getting them to write something more useful about failed experiments than "we didn't measure it right because we're stupid" in the reports.

@rob good.

I once had a lab where my percent error was something like 300%, and I learned so much from that assignment because it forced me to critically analyze my procedure. Getting terrible results is usually a better learning experience than getting the expected ones (unless the discrepancy is just due to carelessness).

@ZeroTheHero I suspect that the bulk of those "please do my work" questions don't come from people who actually want to learn how to think like a physicist. They come from people who just want to learn how to pass physics exams. But I've said that before. :)

@PM2Ring we can agree on this.

We also shouldn't discount how many people are studying something else and are forced to take some physics class even if they don't really want to

Right but in all fairness high school physics can be like a 4-month long visit to the dentist.

I helped my niece last year and some of her problems were needlessly vicious...

and other were basically dumb memorization.

I can't blame students for not being interested.

Moreover I remember reading (that was many years ago) that something like 60% of physics teachers in UK high schools did not have physics as their primary field of study.

@HDE226868 Yes, indeed. (although sometimes, trying to come up with a better critical analysis than "both experimenters were hungover and the stroboscope made them nauseous" is pointless ;) )

And I guess there's more dumb memorization in physics courses that don't use calculus.

There were like biologists who were "voluntold" to teach physics.

@ACuriousMind "must repeat experiment with lower blood alcohol content to attempt to replicate results" would be a nice conclusion to that. :-)

i don't think I'd do a great job teaching biology, so I can sympathize with biologists having to teach physics.

(and we shall not explore the option of asking students if I actually do a great job of teaching physics)

Modern biology does a lot more number crunching, and manipulating big genome data, but traditionally, biologists have a reputation of not being strong mathematicians. So I wouldn't expect them to be enthusiastic at teaching physics, even at the high school level.

One of my nieces is in biomedical science, and so is her husband. If you want some DNA, or need to analyze mouse lung tissue, she's your girl, but don't ask her to solve a PDE. ;)

Intro bio was always the worst for me (and I never really got further than that). Too much focus on remembering things, and not enough focus on showing understanding. I get why bio starts like that, but I found it hard to do well in those courses, even if I felt like I learned a good deal

She's not a mathematics ignoramus, and did some pretty fancy statistical analysis as part of her thesis, but of course a computer handled the arithmetic.

@ACuriousMind i don't know on what intensity to use the power coefficients when the axis of the polarization of partially polarized light is not parallel to the glass surface.

@Fermiparadox The Fresnel equations are in terms of s-polarized and p-polarized light (perpendicular and parallel to the plane of incidence). All incident light can be split into s-polarized and p-polarized components.

If your light isn't purely s- or p-, then you just compute the reflections for the s- and p-polarized components separately and then add them together again

@ACuriousMind how do I compute them in the case above?

@Fermiparadox The Wiki page for the Fresnel equations has everything you need if you know the incident angle and the polarization. At what step are you unsure what to plug in?

How do you argue with someone that the speed of light is a dimensionless quantity if they think that basic mathematics itself (like 1 = 1) might be untrue in another galaxy?

Is there any simple explanation I can give (that doesn't get into primitive notions)?

@forest The speed of light is not a dimensionless quantity! It's a speed and so has dimensions of distance per time.

Oh then what is it, distance?

(yeah you're right, my brain is dead apparently)

Yeah looks like time and length.

@ACuriousMind In my argument, I was comparing the speed of light to pi, showing how if you change planck length, you also have to change planck time.

Just like changing radius requires changing circumference in a circle.

Does anyone else find the whole "my nomination being removed" is a bit ironic? Supposedly suspensions can cause drama during nomination process; however it wasn't until after my named was removed that drama ensued

@forest Sure, any system of units that fixes the speed of light at a specific value will have that

Modern SI units behave that way, too, since the definition of meter and second is based on a specific numeric value of the speed of light in these units

The bigger issue is the misconception that physics might "vary" based on location and that 1+1 might not be 2 if you move to the Andromeda galaxy.

The typical "we don't know that" argument. The kind I probably shouldn't be having but get sucked into anyway. And physics is not my strong suit. :P

@forest Those are two very different claims. Whether physical laws vary by location is at least in principle a claim about the real world that can be assessed through experiment. "1+1 = 2" is not a statement about the real world

@ACuriousMind I have no issue calculating the coefficients. My problem is I don't know how to break partially polarized light into s,p for arbitrary plane of incidence.

@Fermiparadox Ah! In what form do you have the polarization data given?

@Fermiparadox So you can compute the polarization of the light after glass 1 relative to its plane of incidence, and then re-express that vector relative to the plane of incidence for glass 2

Assuming you know how 1 and 2 are oriented to one another. If you don't, you're out of luck :P

@ACuriousMind hmm I guess I haven't fully grasped the concept of partially polarized light then. It's rather late so I'll go sleep and think about how to express it as vectors. 1 and 2 orientations are known. Thanks for the help, gn

(i mean, I don't have one vector, anyway, have to go)

With homework-dump questions like this, I'm so tempted to comment: "I can think of 4 reasons why someone would post such a blatantly off-topic question: ignorance, laziness, rudeness, or stupidity. What's your reason?". But that would be Unwelcoming... ;)

@JMac You misunderstood. I said, that an answer to John Rennie's question is probably more worthy, than an answer to the question of a rep1 user.