The h Bar

So we have on the agenda: Book policy; Homework policy and clarifications in concept and question; Re-eval list policy?; Improve experience posts; recent physics. Right?

ManishEarth

4:05 PM

New members derailing the discussion. Usually we do that on our own.

ShuklaSannidhya

But H = U + pV right? And U = q - pV. So H = q... always... wait what?

tpg2114

In no particular order

ManishEarth

@tpg yep

David Z

@tpg2114 Yeah, sounds about right.

tpg2114

Knock out the easy ones first? Books and re-eval list?

David Z

4:06 PM

9

A: Reevaluating the book policy

See my answer here for the rationale behind this policy Note that this will require some community members to commit to curating the book questions by adding the banner, flagging+commenting on bad answers, etc. This can't go through unless we get enough people who are willing to patrol fo...

tpg2114

Along with

ManishEarth

(a) do we need more volunteers?

tpg2114

4

Q: Please volunteer for help editing recommendation questions

Recently, the book policy has been reevaluated, and Manishearth's proposal how to change it seems to be well enough accepted. What is still missing for the new book policy to become reality, is some people, who are willing to help with editing the new incoming questions and controlling the answe...

I think we have enough who have volunteered to give it a go. If it doesn't work for lack of effort, it implies there's lack of desire to have book questions and we just change the policy again

David Z

Honestly, this doesn't strike me as something specific people need to volunteer for. Whatever curation is needed is something that can be expected of the whole community, just like with homework questions.

ManishEarth

(b) do we need a point b?

@david hmm, true

tpg2114

4:09 PM

I think what we have is close enough to workable that we should just give it a shot and see how it pans out

Arc676

@ManishEarth If you make a point B, shouldn't you be asking if we need a point C?

David Z

i.e. just as much of the community now flags/comments on complete answers to homework questions, much of the community could flag/comment on trivial answers to resource recommendation questions.

ShuklaSannidhya

Hmm... so chat sessions are for meta discussions not for physics...

That sucks.

David Z

The one other thing I object to is that we don't wikify questions anymore.

@ShuklaSannidhya no, not necessarily

ManishEarth

We need to train the community to the chanhe

David Z

4:10 PM

Usually they're about physics, but when we have meta discussions, those tend to take priority.

tpg2114

@ShuklaSannidhya Only when we have large amounts of meta to deal with

@DavidZ As in we should make more questions CW?

ManishEarth

...which is why I wanted a couple of folks to set an example

David Z

@tpg2114 No, as in we should remove the last sentence of the proposed policy which recommends flagging questions for CW.

ShuklaSannidhya

5 mins ago, by ShuklaSannidhya

But H = U + pV right? And U = q - pV. So H = q... always... wait what?

ManishEarth

@shu we're currently meta-overwhel me d

David Z

4:11 PM

The design of this book policy is such that it's not such a bad thing to be gaining rep from the answers posted.

ManishEarth

@shukla don't forget your differentials

Yeppers

ShuklaSannidhya

@ManishEarth my differentials ?

tpg2114

@DavidZ I view CW as less of a rep thing than a "This question isn't a normal Q&A question and should be dynamic like a wiki"

But I can see how that's just a matter of perception

ManishEarth

@shu writw it as dH=....

David Z

@tpg2114 Well yes, that's arguably true, but then the SE people realized that questions which fit that criterion to be marked CW really just shouldn't be on the site in the first place.

ManishEarth

4:13 PM

dU=q+pdV. Not the same for H

tpg2114

@DavidZ Which is how we arrived at the current "lists and lists-of-books are not on-topic"

ManishEarth

Well, plus or minus

tpg2114

I think if we made it CW it indicates that it's different... but I'm really not that adamant about it either way really

ShuklaSannidhya

TIL, ~~I suck~~ My book sucks at thermodynamics.

ManishEarth

@davidz not exactly, it's " most cw questions ..."

Cheese knife.

David Z

4:14 PM

@tpg2114 Yeah. And I still maintain that questions which are intended to collect a list of answers (like, one answer per, well, answer) shouldn't be allowed.

ManishEarth

@tpg a banner that we edit in should make it dofferent

David Z

The whole point of the new book policy is to explain a way to have resource recommendations that doesn't wind up with them just becoming lists.

ManishEarth

@david I'm p retty unsure of that now, there are really nice list qs on tex and mma

tpg2114

True. I'm just thinking of in-between cases where there is a countably finite set of books, like 2-3

ManishEarth

Im going to have a closer look later and determine so me objetv criteria foe good list

tpg2114

4:16 PM

But any individual person may only know 1 of them

David Z

@ManishEarth IMO those are a misuse of the SE model though.

They technically shouldn't be allowed.

tpg2114

So a CW encourages people to make a single answer with all of them while not-CW makes it more likely to get a handful of answers where no one is the answer

ManishEarth

I dunno... they seem to work. And these usually have multiple points per ans

tpg2114

@DavidZ Is it harder to make a post CW or to un-CW it?

David Z

@tpg2114 Well... I guess so. Actually, CW is supposed to be for things that are intended to be community-editable.

@tpg2114 Neither one is particularly hard, IIRC

tpg2114

4:18 PM

@DavidZ Right, so the top answer would be edited rather than new answers added to keep a "master" list

ManishEarth

@tpg easier to make cw because users can trigger it

ShuklaSannidhya

Seriously guys, do you find Meta more interesting than Physics? :|

tpg2114

Let's try it the least-work way first then. Don't flag to make it CW unless we see it's a problem

ManishEarth

Usually we discuss physics

David Z

@tpg2114 yeah, pretty much

tpg2114

4:18 PM

And then we can go back in and make CW a requirement if we need it

ManishEarth

Yeah that works

David Z

@tpg2114 That works with what I've been saying ;-)

tpg2114

@DavidZ Yup, just conceding the point :) I'd rather give it a go and let the community decide the finer details of the framework than put the extra work up front if it may not be needed

David Z

OK, so, are we resolved to remove the CW requirement?

tpg2114

Works for me

David Z

4:21 PM

The other thing I'd like to do is to edit in some examples of the kind of answers we're looking for, for resource recommendations. I happen to know of one because I wrote it, but we should be able to find a couple more.

ManishEarth

Yep

Crazy Buddy

Phew... Back from family crowd :D

tpg2114

Sounds good

ManishEarth

What we can do is inaugurate the policy with a question

(any ideas as to which topic)

Arc676

Where would I ask a question not relevant to the current conversation if none of the other chat rooms have active members (except asking a question)

David Z

4:23 PM

@Arc676 Oh, you can still ask it here

ManishEarth

You can still ask here

Parallel convo is ok

tpg2114

@Arc676 Just don't be surprised to see it interwoven with other conversations

ManishEarth

Heh

Arc676

The site on which I learned to draw feynman diagrams has "exercises" to practice, but there are no solutions. One of them was to have a single muon decay into photon and an electron. How would I do this?

tpg2114

@DavidZ So is the next topic whether we should re-evaluate lists in general? We sorta touched on it

Crazy Buddy

4:24 PM

@Arc676 We have pings..!!! We can reply for specific msgs (though you can't really expect an answer from anyone, which is also based on your question) :D

ManishEarth

I assume neutrinos are involved

Crazy Buddy

Alright members, we don't allow list questions... Right?

David Z

@tpg2114 Yeah, but first let's double-check that we are set on the book policy: remove the bit about CW, edit in a couple of examples, and then convert it to faq?

Arc676

@CrazyBuddy "List questions"?

ManishEarth

Not yet, no

tpg2114

4:26 PM

@DavidZ Aye, works for me.

David Z

@Arc676 It doesn't. A muon decays into a neutrino, and antineutrino, and an electron. There will be a virtual W boson involved.

Crazy Buddy

I'm still confused with the book policy. If some equivalently book question arises, we can use the CW. Can't we?

ManishEarth

I think @asheeshr on Reverse Engineering has managed to make them work

Sklivvz

Ugh list questions are really bad

David Z

@CrazyBuddy for now there will be no CW'ing of anything

Crazy Buddy

4:27 PM

@Sklivvz Yeah, but most of the betas have at the start itself o_O

@DavidZ Alrighty then :)

Flavin

@Arc676 From en.wikipedia.org/wiki/Muon#Muon_decay: "Certain neutrino-less decay modes are kinematically allowed but forbidden in the Standard Model. Examples forbidden by lepton flavour conservation are: $\mu^- \rightarrow e^- + \gamma$"

Sklivvz

@CrazyBuddy we are not a beta site :-)

tpg2114

@Sklivvz I second that. And I also think it diminishes the level of things. Lists aren't very conceptual or intellectual typically

Arc676

@DavidZ Could you have a muon decay into a neutrino and emit a W- boson, which decays into an anti-neutrino and an electron, and then have the two neutrinos interact, or would this violate causality?

Crazy Buddy

@Sklivvz We were... That's how book question came in. Right? o_O

David Z

4:28 PM

I am also opposed to list questions, in the sense of "post your favorite X, one per answer"

ManishEarth

@tpg they can be, and that's something we can capture

Sklivvz

resource questions are sometimes better, if voting makes sense

ManishEarth

Oh, "favorite" qs suck

Crazy Buddy

@DavidZ Me either... I try to close all such questions...

David Z

@Arc676 No, that could happen, but it would be exceptionally rare because neutrinos are so weakly interacting.

tpg2114

4:29 PM

@DavidZ I'm opposed to the "What experiments show X" though since it's a potentially huge list that needs constant revision as time evolves

ManishEarth

But what about qs like "what are some things a newbie should know about mathematica/tex?"

("common pitfalls")

Sklivvz

if you ask what are the best books on the Higgs mechanism, it's sort of fine because the list remains valid in time, but if you ask what are the best academic articles on a cutting edge topic, the question needs constant maintenance.

ManishEarth

That question is awesome on both sites

Sklivvz

in general the SE model works best for tertiary information

Crazy Buddy

What I meant by an equivalent "book" question is... some CW post planned by the community (say chat)

David Z

4:30 PM

@tpg2114 Hm... well, you could make that argument about a lot of questions here. Things do get out of date. If the question is phrased as "what is the experimental evidence for X?" then I think it's okay, even though it will get out of date over time.

Arc676

@DavidZ So the two neutrinos (also shown in the muon decay diagram from @Flavin's message) can interact WITHOUT violating causality?

ManishEarth

@skli see my meta book policy proposal, nothinb to do with "best"

Sklivvz

@ManishEarth what about it? can't it be a tag wiki?

David Z

@ManishEarth I'm opposed to that kind of question. If we want to say that they're generally forbidden but a few specific exceptions will be allowed on a case-by-case basis, I'd be okay with that.

@Arc676 Yep... don't take the Feynman diagram too literally.

ManishEarth

It's not just asking for recs. It asks for more

Have a look at it (there are two, one with rationale one with policy)

tpg2114

4:32 PM

@DavidZ I think that example is okay because usually there aren't huge breakthroughs all that often. But "list of experiments" could change daily as incremental changes to experiments only provide incremental verification or something.

ManishEarth

In 5 mins ill be able to link

Arc676

@DavidZ What do you mean too literally? On a different topic, does time HAVE to go in a certain direction, or can it be either horizontal or vertical?

David Z

@tpg2114 Well yeah, if it's just "what are some cool experiments I should know about?" or something like that, I'd definitely put that as off topic.

Sklivvz

The point is that we have questions like stackoverflow.com/questions/121243/…

tpg2114

But I think the subtlety is not terribly relevant since we agree on lists being off topic :)

Sklivvz

4:33 PM

(which I asked by the way)

you can't navigate the questions, etc. etc.

voting is pointless

David Z

@Arc676 I mean that just because a Feynman diagram shows interaction A happening to the left of interaction B, doesn't mean that interaction A literally has to happen at an earlier time than interaction B. And time doesn't have to flow in any particular direction.

Sklivvz

there is no way a new answer can emerge if late

Crazy Buddy

@Sklivvz Yeah, that's right. It starts working like meta :)

tpg2114

So it looks like the majority of discussion here is anti-list

Arc676

@DavidZ So as long as I indicate the time axis I can have time go from bottom to top, top to bottom, left to right, or right to left?

tpg2114

4:35 PM

But really we are just trying to decide if it's worth looking at re-evaluating right?

David Z

@Arc676 Yep. But either left-to-right or bottom-to-top is conventional. You might confuse people if you make a different choice.

ManishEarth

Yes

tpg2114

My vote on that question is that it never hurts to evaluate policies but I personally wouldn't put too much effort into it

Arc676

@DavidZ Right

tpg2114

If only because it doesn't seem like it will change, but people not here may have other opinions

ManishEarth

4:36 PM

I think a good forage around the network for examples of successful and unsuccessful, good and bad lists would help

Also a talk with the mods of the sites that allow 'em

tpg2114

Full steam ahead if you want to :)

ManishEarth

OK, i'm on a keyboard now. Prepare to face Manish 2.0!

....who has nothing to say at the moment :o

David Z

OK, so if we could back up for a moment: for examples of good answers to book questions, I have 1 2 3 4 5 6

thoughts?

ManishEarth

I like #1

tpg2114

I think they are good

Crazy Buddy

4:42 PM

@DavidZ: So, the answering fellas write reviews about their experience with the books. Right? :D

ManishEarth

#2, not so much but still good

David Z

We don't need all of them of course, just a couple examples to put into the book policy

@CrazyBuddy Not necessarily. It's more like, giving a short description of the merits and pitfalls of each book.

ManishEarth

#5 is awesome

#4 is borderline but okay

Crazy Buddy

@DavidZ Oh, that too - yeah :)

tpg2114

@DavidZ Which means it needs to be "Books I have actually read" as opposed to "Books I found by typing your terms into my library"

ManishEarth

4:43 PM

exactly

among other things

tpg2114

Which might want to be stated clearly somewhere

David Z

@tpg2114 Mostly that would be ideal, but sometimes you can characterize a book based on its reputation. I wouldn't say you need to have read the book, but you need to be familiar enough with it to describe it.

ManishEarth

@Sklivvz Start here (rationale, and why it will work), end here

15

Q: Reevaluating the book policy

Related: Good list, bad list Currently, book-request questions more or less have a blanket ban on this site. I'm seeing if this can be changed, to allow for a relaxed book policy that permits book requests with some constraints. If there is consensus on this, we can convert this to a meta-f...

discussion feature-request policy book

tpg2114

@DavidZ That's fair.

ManishEarth

that will be faqed when we're finished

David Z

4:46 PM

So, #1, #5. How about #6 as a third example?

ManishEarth

Yep

this is about resource requests, not just book requests, so that works too

Feel free to edit it into the meta post linked above, obviously

David Z

Indeed, I'm about to do that

tpg2114

So are we on to the other elephant in the room, homework?

Crazy Buddy

BANNNN..!!!

Anonymous

@tpg2114 I don't explain it here because I'll again be accused of violating "Be Nice", etc.

ManishEarth

4:49 PM

Looks like Sklivvz is off fixing bugs

@DIMension10 you can discuss it politely. But off topic.

Crazy Buddy

@DIMension10 Then, be nice :P

Sklivvz

oh i just broke the main site. that bug was nothing

ManishEarth

@Sklivvz howwwww??

Arc676

@DavidZ I forgot to ask earlier, but to summarize: for a muon to decay into an electron and a photon, is it possible to have the muon emit a W- boson, decay into a electron-neutrino, then have the W- boson decay into an electron and an electron anti-neutrino which interacts with the before-mentioned neutrino to annihilate into a Z boson, which then decays into an electron pair, which annihilate into a photon?

Sklivvz

meta.stackoverflow.com/users/811/shog9?tab=votes&sort=all

Crazy Buddy

4:51 PM

@ManishEarth Now, aren't you black? (your \mu is black) Wait... First, is that you? :D

tpg2114

I actually had a dog eat my French homework back in high school once. I got yelled at for lying to the teacher and being completely insulting by using such an unoriginal excuse

ManishEarth

@CrazyBuddy nope

@Sklivvz we can't see that, dummy

Sklivvz

this -> meta.stackoverflow.com/users/current?tab=votes ?

ManishEarth

yay broken stuffs!

tpg2114

At any rate, I think the rehash of @ManishEarth that @Nathaniel posted makes the most sense for homework. Change it from "Yes but only if you show some work and ask about a concept" to "No, but if you can ask about a particular concept"

4

Crazy Buddy

4:53 PM

@Sklivvz Nopesey...!!!

ManishEarth

stray quotation marks?

Sklivvz

you need to go on your user on meta.so and click on votes

ManishEarth

@tpg2114 agree. because it was my idea, and I'm not schizophrenic on meta like you :P

David Z

@Arc676 Not quite, if I understand what you're saying. The muon decays into a W- boson and a muon neutrino, then the W- boson decays into an electron and an electron antineutrino. The electron antineutrino and the muon neutrino won't directly annihilate, but they could interact via the exchange of another W boson.

ManishEarth

@Sklivvz @CrazyBuddy replaced it with a universal link

tpg2114

4:54 PM

@ManishEarth You don't know me well enough yet, but I'll debate any side of any topic whether I agree or not. All sides deserve representation :)

ManishEarth

true. So do I, but I usually do it inside one answer :P

Arc676

@DavidZ So with this interaction with the W boson, how could these two neutrinos annihilate each other, or is this not possible? Because the tutorial asks that the final state also includes a photon

tpg2114

But then what does voting mean? This way people can choose which of my multiple personalities they like or don't like

ManishEarth

@tpg2114 oh no, when I do this I form an internal dialogue with it and display it. I eventually come out on one side, but the other points all get mentioned

But this works too

David Z

@Arc676 They can't actually annihilate each other directly.

Arc676

4:57 PM

@DavidZ So does this mean that it's impossible for this process to have a photon in the final state?

ManishEarth

OK, one sub-point regarding homework

Dilaton pinged me about in on MSO chat, and I feel it deserves some thought

David Z

@Arc676 The only way I can think of for a muon to decay into an electron plus a photon, and nothing else, is muon -> muon neutrino + W-, then W- -> electron antineutrino + electron, then the muon neutrino would have to oscillate into an electron neutrino, then the electron neutrino and electron antineutrino could exchange a W boson and convert into an electron and positron, then the electron and positron annihilate to produce a photon.

That's incredibly unlikely.

ManishEarth

in Tavern on the Meta on Meta Stack Overflow Chat, 5 hours ago, by Dilaton

@Manishearth I hope Physics SE will not really go closing or even deleting all the nice advanced technical questions about CFT, ST, etc as tpg2114 wants to. For example the questions asked by user 26143 are very valuable for all people who are studying these topics at an advanced level, and he always gets immensely nice answers by Trimok and others.

Sklivvz

@ManishEarth fixed now

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