The h Bar

0celo7

4:00 PM

can I propose a topic

user228700

What screens what?! I'm very confused about screening effect now, dang it :/

David Z

@0celo7 what is it?

0celo7

Teach 0celo7 how to Word

John Rennie

@Kaumudi Shush, physics chat now. Physics only!

David Z

@0celo7 nah, I'm vetoing that. Plenty of time outside the session.

OK, let's get started.

0celo7

4:01 PM

wtf

David Z

Welcome to our biweekly chat session, everybody!

Please keep unrelated discussion until after we've finished with the topics on the agenda

Terry Bollinger

The topic is...?

John Rennie

If we're short of things to talk about I have a suggestion but I fear it won't be popular.

0celo7

just because I present a gruff, manly exterior doesn't mean I don't have feelings...

David Z

Today we don't really have much of an agenda:

1. Intro, welcome newcomers, site questions (10m)
2. Recent physics developments (20m)
3. Quick overview of meta stuff and whatever (5m)
4. Open discussion

ACuriousMind

4:02 PM

@JohnRennie Does it contain the words "home" and "work"? :P

David Z

@JohnRennie we are, as a matter of fact

John Rennie

OK, I'll contain myself until step 4

David Z

For now, who is new to chat sessions, to the chat room, or to the site?

0celo7

@rob Shouldn't you be teaching?

David Z

Yay @rob you made it for a moment :-)

0celo7

4:03 PM

Omg are you texting in class?

user228700

I'm new to the sessions! I've never been here for one of these before...

David Z

Everyone welcome the new mods before rob has to go :-P

0celo7

Hello @ACuriousMind @rob

John Rennie

@DavidZ how far do we have to bow? :-)

0celo7

I've heard terrible things about @ACuriousMind but I hope everything works out all right

:)

David Z

4:03 PM

@JohnRennie that's up to them

Terry Bollinger

I'm behind, the new mods are?...

0celo7

@TerryBollinger : @ACuriousMind @rob

David Z

@Kaumudi well how about that, you've been here so much I would never have guessed. Welcome to the chat session! We do this every couple of weeks to get people together and discuss issues of importance to the community, if there are any.

Terry Bollinger

Sounds good.

David Z

Anybody else new?

user228700

4:04 PM

Okay, cool!

David Z

This is also a good time to ask basic questions about how to use the site, if you have any

(we don't have to stick too closely to the schedule because there's no major topic of discussion today)

DanielSank

I'd like to mention bookmarking in chat.

4

Two people in the last week expressed surprise when I used it :D

It's not obvious how to do it when you're actually in a chat room.

How to do:

1) On top right of screen, click the "info" link.

2) Click "view transcript"

3) You're now looking at the room's history. You can navigate by day and time.

4) On the right is a button "bookmark a conversation". It's pretty self explanatory from there.

David Z

There's also "room" > "create new bookmark"

PhyMan

hey everyone!

DanielSank

You can see all conversations from the screen you get to after step 1, by clicking the "conversations" tab.

David Z

4:08 PM

Hi @PhyMan

DanielSank

@PhyMan Hello.

@DavidZ Oh, wow! I didn't know that!

David Z

@PhyMan you new to these parts? (by which I mean chat)

Slereah

Hey look who's back

DanielSank

Ok, never mind, everyone, use @DavidZ's way.

Much easier.

0celo7

@JohnDuffield Hey!

PhyMan

4:09 PM

yeah i am @DavidZ

DanielSank

Well, it's easier if you're trying to bookmark a recent conversation.

Slereah

isn't he banned until kingdom come

0celo7

349 days left

David Z

@Slereah Suspended from posting in chat, yes. No need to dwell on it.

@PhyMan welcome!

Slereah

I say let's forbid his dwelling!

DanielSank

4:10 PM

Oh come on.

0celo7

@JohnRennie Crikey!

David Z

@PhyMan Hope to see you in more of the chat sessions in the future

OK, let's move on to recent physics developments. What's been happening in the world of physics lately?

PhyMan

I didnt know these things existed until now

user116211

Researchers road-test powerful method for studying singlet fission

David Z

I hear there was a Nobel Prize announcement...

PhyMan

4:11 PM

Whens the next one?

user116211

@DavidZ yeh ;)

David Z

@PhyMan We have them every two weeks

Secret

Mystery of the cold spot deepens

Slereah

I won the nobel prize

PhyMan

okay

vzn

4:12 PM

Oct 13 at 23:00, by vzn

Gravitational Waves May Permanently Alter Spacetime / pbs

Slereah

I think it was peace

0celo7

What does that even mean @vzn

user116211

Oct 4 at 13:01, by MAFIA36790

BREAKING NEWS #NobelPrize in Physics 2016 to David Thouless, Duncan Haldane and Michael Kosterlitz https://t.co/5jw75GIjRv

Tweeted by NobelPrize on October 4, 2016 at 9:47 AM

PhyMan

Does anybody have any good resources on gravitational lensing?

Secret

That alien megastructure proposed star mystery is even stranger than we thought

David Z

4:13 PM

@PhyMan let's keep that until we get to open discussion later

Slereah

I think Straumann has a chapter on it?

DanielSank

@PhyMan That's a pretty general question! You want a textbook or what?

0celo7

@Slereah Do you have that book?

PhyMan

yeah textbooks fine @DanielSank

Slereah

I do

vzn

4:13 PM

@0celo7 lol thought you werent into the gravitational wave stuff :P

DanielSank

@PhyMan Ok, will ask my secret source.

0celo7

@Slereah proof?

@DanielSank Your wife is not secret

David Z

@Secret yeah, I keep hearing about that

PhyMan

I'm just trying to solve a problem i'm stuck at related to it @DanielSank

0celo7

Well

At least I hope she's not @Secret

Slereah

4:14 PM

oh wait

David Z

Y'all are lucky we don't have real topics to talk about today :-P

Slereah

Did I have Straumann when I took that photo

user116211

@Slereah WoW!

DanielSank

@PhyMan I'm no expert, but I asked my wife for a recommendation.

user116211

Do you stack books like that and make a fort?

DanielSank

4:15 PM

(via email)

PhyMan

and?

Slereah

yes

user116211

;)

Mark Mitchison

I would actually be curious to discuss the topological matter Nobel. Does anybody here actually use the work of Kosterlitz, Thouless or Haldane?

Secret

Any updates on any particle stuff, so far the only thing I have seen are sterile neutrinos searches still empty?

Mark Mitchison

4:15 PM

I guess not otherwise there would be a bit more related activity on the site

DanielSank

@MarkMitchison Hi! Good to see you.

0celo7

@MAFIA36790 are you more impressed by his book collection than mine?!!

Mark Mitchison

@DanielSank Hi Daniel!

vzn

@MarkMitchison would like to learn more also, isnt it related to a "hybrid" state of matter? apparently with wider/ mounting applications

David Z

@MarkMitchison probably not. We're kind of dominated by QFT and fundamental particle physics (if anything), where topological things are... less relevant, I guess

I'm not actually sure what the prize research was really about. I didn't get to read much about it.

@Secret Yeah, nobody's finding any new particles AFAIK

Slereah

4:17 PM

there's plenty of topology in QFT

user116211

@0celo7 I am seeing no Bourbaki in his stack ;/

0celo7

I know some topology

Mark Mitchison

@DavidZ Really? I thought that topological aspects of QFT were rather important in research these days.

0celo7

^they are

Not sure what David is talking about

David Z

@MarkMitchison but less so in fundamental particle physics, that I know of

That's my point

Mark Mitchison

4:18 PM

I suppose that the difference is that the Nobel was for low-dimensional states which wouldn't arise in particle physics

i.e. one or two spatial dimensions

vzn

@MarkMitchison is there any connection to the so-called "mesoscale"? read a paper on that by famous physicist, trying to remember his name

Terry Bollinger

Speaking of topology, is it OK if I give a link to my elaboration of the 1979 Glashow cube for organizing fermions and (my addition) organizing color and anti-color charges? It's for a paper I'm working on...

David Z

Topological QFT is very important in large-scale highly ordered systems, I'm just saying that's not the sort of thing we seem to get a lot of questions on.

ACuriousMind

@MarkMitchison cc @DavidZ topology is very important also in high-energy QFT for phenomena like instantons, domain wall and magnetic monopole

Slereah

We mostly get boring questions

ACuriousMind

4:19 PM

That's not exactly particle physics, but it is HEP

Slereah

A domain wall is just a state with lots and lots of particles!

Mark Mitchison

@ACuriousMind RIght but those phenomena are relevant for HEP in three spatial dimensions, right?

Secret

@DavidZ chat.stackexchange.com/transcript/message/32991763#32991763

David Z

@ACuriousMind hm, I thought those were more niche topics (and only moderately high energy)

@Secret what are you looking at me for? ;-) @TerryBollinger sure, why not

Mark Mitchison

@DavidZ More importantly, we don't really have many experts to answer such questions. David Bar Moshe and Urs Schreiber give excellent answers on topological issues in QM but I'm not sure they're still active?

ACuriousMind

4:21 PM

@MarkMitchison Yep

David Z

@MarkMitchison Yeah, I haven't seen them around in quite a while

Secret

@DavidZ just want to refer terry's message for you, because I am interested in his, but only a mod can answer that question

ACuriousMind

@MarkMitchison DBM appears whenever someone asks about Berry phases ;)

Mark Mitchison

ha

0celo7

Urs is probably tied up in @ACuriousMind's basement o.o

he's extracting knowledge

David Z

4:22 PM

hm :-/

0celo7

I should head to class

David Z

Well, in the interest of keeping things moving along... did anyone read about the Nobel research in any detail?

Even a good pop-sci article?

0celo7

don't cause too much trouble while I'm gone

Terry Bollinger

Nothing profound, but I was pleased how smoothly the usually messy color relationships show up (RGBQ=0 covers.. a lot!). Chained vectors predict baryons and mesons, too, which is something Glashow did not mention in his cube:
https://goo.gl/ZFtNNF

ACuriousMind

@DavidZ I would struggle to name a part of theoretical HEP/QFT investigations that's not currently niche ;)

David Z

4:23 PM

@ACuriousMind a fair point

user116211

Oct 5 at 18:16, by MAFIA36790

28

Q: Topology and the 2016 Nobel Prize in Physics

I was very happy to learn that the work which led to the award of the 2016 Nobel Prize in Physics (shared between David J. Thouless, F. Duncan M. Haldane and J. Michael Kosterlitz) uses Topology. In particular, the prize was awarded "for theoretical discoveries of topological phase transitions an...

0celo7

@MAFIA36790 I will pile my books on the floor in one giant stack and take a picture

you will be impressed

user116211

@0celo7 Make sure it looks like a fort or a castle.

user116211

@0celo7 ;))

0celo7

No it will look like a tower

user116211

4:24 PM

@0celo7 Good!!

user218912

@0celo7 and then it will fall over and damage your books.

David Z

@MAFIA36790 that helps. Surprisingly readable for MO content.

Terry Bollinger

@Slereah Domain walls and solitons, essentially how to resolve conflicting domains -- fun stuff, that...

user116211

Yeh, that MO post is good.

Slereah

Domain walls are nice because they allow large static violations of the NEC

Although not that large

IIRC it's basically the same kind of effect as the Casimir effect

Secret

4:26 PM

@TerryBollinger So you mean in chi space a given color charge is a superposition of two others?

Slereah

Not sure what would be the violation of the NEC from some Higgs domain walls

0celo7

@bl00 good point

user116211

@0celo7 You should use stack holder.

David Z

Let me take advantage of this lull in the conversation to move to our next (and last?) topic: I just want to give a quick overview of meta-type stuff to think about over the coming weeks.

As many people know, we're in the midst of a long-term project to replace the homework-like close reason with something(s) else. We'll return to this more in the future; for now, let's think about this featured meta question:

12

Q: What are the goals of this site?

This discussion question is inspired by this post on the current homework policy question. The main question is What are the goals of this site? Some things to think about when answering: What is it we want this site to represent? What are the ideals to which we should hold all of the conten...

discussion featured scope content-level

There was some discussion about that before the election. What I'd like to do now that the election is over (though not literally now) is come to some consensus on the answer.

Again, just something to think about.

Terry Bollinger

@Secret I'm very cautious to say much more than the figure and labels provide a surprisingly effective mnemonic both for fermion charges and for finding legal baryons. Garrett Lisi pointed out some mappings of my figure into his model for me, but that just made me realize I need to get much deeper into some aspects of symmetry groups that I don't feel I understand well enough.

John Rennie

4:32 PM

> come to some consensus on the answer

What's a consensus?

Secret

i see

Terry Bollinger

Oops, looks like we moved on to site issues, sorry.

David Z

@JohnRennie Something that almost everyone can agree on. Basically, a compromise (though it need not be a compromise if everyone thinks similarly to start with).

John Rennie

Clearly not a term physicists use :-)

DanielSank

I don't want to derail this conversation, but I do have an opinion about this:
I think that question is way to broad to be useful. That post came out of the effort to clean up the homework policy, and as such I see it as an unfortunate diversion.

David Z

4:32 PM

@TerryBollinger no worries, we'll go back

DanielSank

(I know I should use the meta to find out if others agree; I haven't put in the effort to write the post yet.)

vzn

@DanielSank somewhat agreed, have been chatting with heather, asker of that question, shes a middleschooler interested in coding etc

David Z

@DanielSank we've got time to go over this more

There are also some mother meta posts that people might want to be aware of. They're featured in the community bulletin box.

DanielSank

Anyway, I think that we can fix the biggest problems in the homework policy without having to solve the impossible problem of coming to a community consensus on the purpose of the site.

David Z

163

Q: A proposed philosophy of question migration

We spend a fair amount of time talking about question migrations between sites. These conversations happen internally, publicly and semi-publicly in the network-wide moderator chat room. In the interest of reducing the time we collectively spend discussing it, let’s see if we can formulate a cle...

discussion featured migration

104

Q: Let's Plan The Second Iteration Of The Stack Exchange Quality Project!

In case you missed the first one, check out the se-quality-project tag. The quality project isn't one that we plan to ever finish, it's perennial and kicks in every 18 months or so after we've had ample opportunity to observe the efficacy of our previous efforts, changes in how people use our sit...

discussion featured se-quality-project

DanielSank

4:35 PM

We do not all agree on the purposes of the site. I don't think we necessarily even should all agree.

I'm sure there is common ground, and it's worth finding it and even writing it down, but I don't really see that as an important or necessary element of fixing the homework policy.

David Z

And the last thing worth mentioning is probably the recent election, which (almost?) everyone knows about by now

DanielSank

I'll leave a link to what I think we should do to fix the homework policy, and note that it's been edited since it was originally posted.

David Z

25

Q: 2016 Community Moderator Election Results

Physics's third moderator election has come to a close, the votes have been tallied, and the 2 new moderators are: They'll be joining the existing crew shortly — please thank them for volunteering, and share your assistance and advice with them as they learn the ropes! For details on how th...

discussion featured election

vzn

Homework, the Endless Saga™

David Z

That's all I've got for now. Open discussion time! You can talk about the homework policy or the Nobel research or whatever

...or whatever @JohnRennie wanted to suggest?

John Rennie

4:38 PM

@DavidZ let me get this over with quickly because you'll all disagree ...

vzn

nobel research seems to have connection to transition points in materials... does it have any connection to spin glasses? (where transition point(s) are highly studied, & even some deep connections to CS)

John Rennie

but I think we need a companion site where we allow homework questions

More precisely where we will help people work through problems and worked examples.

David Z

Physics Forums isn't good enough?

John Rennie

The way the SE works is a million times better than Physics Forums.

0celo7

Physics forums is terrible

ACuriousMind

4:40 PM

@JohnRennie You mean, where other people will help people work through problems and worked examples, right?

John Rennie

Physics Forums is littered with people who think they know more than they do and outright cranks.

0celo7

half the threads end with OP saying, "oh I figured it out"

and no explanation

ACuriousMind

That's the problem - you need to find the answerers for that site.

David Z

@JohnRennie For conceptual Q&A, yes. But for homework help, I'm not so sure.

vzn

"forum" the 4-letter word on SE... o_O

John Rennie

4:41 PM

@ACuriousMind well I'm finding it surprisingly fulfilling helping with problems in the chat room

David Z

Still, the idea of a physics homework site isn't the craziest thing. There have been proposals to that effect on Area 51

John Rennie

I think that if i believed an OP was genuinely interested I'd be willing to devote some time to a Physics Education SE

ACuriousMind

@JohnRennie Yes, because you enjoy the direct and positive response you get in chat, and because the people in chat tend to be much more willing to learn than the average person seeking help on the internet

John Rennie

I think any such site would have to require that OPs made an effort.

Secret

The process of solving of some homework problems is actually itself interesting, because some common problems have solution pathways that actually makes one to think

John Rennie

4:43 PM

No-one is going to enoy just doing people's homework for them

David Z

@JohnRennie they might if it's interesting enough homework

ACuriousMind

@JohnRennie And then you'll have a community continually warring over "how much effort is enough?"

John Rennie

My thought is that we need an SE whose aim is teaching physics

David Z

@ACuriousMind To be fair, we continually fight about that here, and this site still works

0celo7

@ACuriousMind my QM prof said "vectors are defined by how they transform under rotations"

What the hell does that mean

John Rennie

4:44 PM

And I think doing worked examples is an important part of the teaching process

2

Terry Bollinger

@JohnRennie makes more sense than just doing homework.

0celo7

What even is a rotation if we don't have a notion of vectors?

David Z

@JohnRennie Well, ostensibly our aim here is also teaching physics. So it would be important to clarify just how this new site's contribution to teaching physics would differ from what we do here.

John Rennie

@DavidZ the current homework policy (which I wholeheartedly support) really limits our ability to teach physics.

Terry Bollinger

@DavidZ teaching is... different, harder.

ACuriousMind

4:46 PM

@DavidZ Yes, but my impression was that John wanted to solve our continual problem. In this case, by exporting it to a new site

Secret

I think in such framwork, Physics Edu SE will differs from PSE in that the latter is more conceptual based understanding of physics, while the former will focus more on cultivating users the ability to solve problems via worked examples and thinking methods

Terry Bollinger

You have to get into the mind of the questioner.

John Rennie

@DavidZ If someone posts a question from a physics book we close it as homework, when the whole point of textbooks including problems is that they are an important aid to learning.

@ACuriousMind you make it sound like I mean the new site to be a rubbish dump, and I don't.

But I do anticipate it would clear out some of our unwanted questions here.

Terry Bollinger

@Secret what I'm doing in my Xi space model is treating electric and color charges as non-orthogonal components of a single anisotropic 2-sphere of charge, with electric being the non-orthogonal part and quantization allowing only certain vectors to exist. It still surprises me how well it works as an organizing principle. But yes, it's just linear superposition, with Q as an unexpectedly useful "helper" to distinguish between acceptable combos of color charge as seen in actual particles.

John Rennie

But ...

David Z

4:48 PM

@JohnRennie Well, yeah. After all, if we do the question, we are the ones who are learning, not so much the asker. But that's not the point here.

John Rennie

No new SE site is going to get off the ground without a group of people who really believe in it

David Z

@JohnRennie It could be seeded with like-minded contributors to this site

Terry Bollinger

@DavidZ you are both proposing a "physics teaching" site?

David Z

This is all John's idea

John Rennie

Well I'd be willing to be in the group getting it started, and finding 40 sample questions would just be a matter of exporting our homework tag :-)

But I fear I'm in a minority of one

ACuriousMind

4:49 PM

@DavidZ Finding those is what Area 51 is for, isn't it?

David Z

If there are enough people who want to set that site up, go for it. I personally would not be interested in participating, though. (Well, I think. I'd have to see how it goes.)

@ACuriousMind yeah, but it tends to go better if you have a decent-sized group interested from the start

ACuriousMind

@JohnRennie I think you're not, look at how many people post explicit answers to homework questions. However, look at how many people post explicit answers to homework questions without any pedagogical value whatsoever

Terry Bollinger

@JohnRennie are you planning to propose an Area 51 group? Or checking interest first?

ACuriousMind

So I kind of fear you'll go in there having this idealized notion of teaching people how to do problems by example, and you'll get a site filled with people just wanting their homework done and others giving it to them.

John Rennie

@TerryBollinger There is no point in starting an area 51 proposal without first getting together a core group of committed people.

@ACuriousMind well that's kind of what happened to the math SE, but it hasn't been fatal.

I still see lots of good answers explaining methods without just typing out the answer

Even though yes there are people who just post answers to homework, presumably to show they can.

David Z

4:54 PM

@JohnRennie well, there is some point. You can start the proposal and have it serve as an "anchor" - a central source of information and a place to register interes

John Rennie

@DavidZ without at least three supporters a proposal is deleted in three days ...

David Z

@JohnRennie oh I didn't know that. Well, never mind then. Still, having three supporters shouldn't be too hard.

John Rennie

> having three supporters shouldn't be too hard.

Really?:-)

Terry Bollinger

@JohnRennie surely you can get 3 supporters? You are a very apt vetting point.

ACuriousMind

@JohnRennie Well, it's not been fatal in the sense that it didn't die as a site from that, but I absolutely don't like visiting math.SE (and I know several others who feel the same).

John Rennie

4:56 PM

@ACuriousMind yes, I agree, and if that happened here I would be most upset. But the whole point of the new SE would be to help with problems.

Most of us here would have little to learn from it and probably wouldn't visit it.

@DavidZ: could we use a meta post here for recruiting for a new proposal?

David Z

Sure

It's been done before, I believe

Terry Bollinger

@JohnRennie devil's advocate: What exactly would a physics teaching site add that is not already in existence elsewhere?

John Rennie

@TerryBollinger The way the SE rep system works is very good at identifying the answerers who know what they're talking about.

And the answers that are good.

The problem with the Physics forum is that you get answers that are total bollocks and the student won't necessarily be able to spot this.

David Z

Anyway, not to cut off the discussion but our time for the chat session is up. So see everyone in two weeks!

John Rennie

The big advantage of the SE system is the reliability of the answers.

Terry Bollinger

5:01 PM

@JohnRennie yes, that is what I like most about the SE incentive system (vs Wikipedia, which can end up assassinating true experts more often than supporting them).

John Rennie

OK, the impression I get is that no-one thinks the suggestion is completely silly, though by the same token you aren't all beating on my door. Is that a fair summary?

David Z

Seems like it from my perspective

0celo7

Yes

Terry Bollinger

@Secret if you are still there, the origin of the figure was to remove "noise" in the original rishon (parton) model, which led to three axes, which turned out to be isomorphic to color charge axes. In short, my goal for a paper with that figure is mainly that the source of the ordered rishon triple structure is simply the color charges of the strong force.

Secret

ok

DanielSank

5:07 PM

@JohnRennie Why do that as an SE site?

John Rennie

@DanielSank because I like the way the SE system works.

DanielSank

But for teaching?

John Rennie

And it's free ;-)

DanielSank

Yes but could you give an example of a good Q&A on that site?

John Rennie

A good Q would be an exercise from a textbook where the OP shows they've attempted to tackle it but haven't hit on the correct strategy and got stuck.

Terry Bollinger

5:11 PM

Later all. @JohnRennie I'd volunteer but I'm not a physicist by training, so I don't know if you'd want me, and I would not feel the least bit bad if you don't. But I like teaching and I think I'm better at most than trying to Khan the concept sequence (get at the kernel of the idea and avoiding throwing noise at the questioner).

0celo7

@JohnRennie cough JD cough

John Rennie

@TerryBollinger If the mods are happy with the idea I'll work up my idea into something tangible and post it in the Meta with a call for volunteers.

Secret

and a good A might be the various strategies on how to break down the problem, such as the various physical intuition employed, what in the problem or working steps that can advise the next step in the solving process, IMO

as well common mathematical tools in simplifying the problem(...not sure about this last one?)

John Rennie

@0celo7 I think the voting system has worked reasonably well in that case.

DanielSank

@JohnRennie I see.

0celo7

5:14 PM

@JohnRennie he has like 6000 rep

John Rennie

@0celo7 and lots of visible downvotes i.e. there is hardly an answer of his that isn't downvoted. Not perfect but better that it would be in the physics forums.

In the absence of perfection I'll happily take second best.

Shing

The voting system practically compel me to think twice before asking or answering. That's the up side of SE I think

Terry Bollinger

@JohnRennie John, if such a call comes up I'll very likely respond, but only for answering questions where I'm confident I'm accurately reflecting the parts of physics I know well.

Shing

Although sometimes I have seen silly questions or okay answer get high upvote. but that doesn't bother me.

John Rennie

@TerryBollinger thanks terry. The hard bit will be getting things moving. I think if we can get the site going we should be OK. If nothing else we could migrate the unwanted questions from here.

Shing

5:18 PM

but on the other hand, freedom to express what I think is always some upside of physics forum. I would say it is hard to compare apple to orange in general.

Emilio Pisanty

0

Q: Using sansmathfonts on the arXiv

I am writing a paper that uses the sansmathfonts package, and I am trying to upload it to the arXiv. Unfortunately, this runs me into the error LaTeX Error: This NFSS system isn't set up properly. and no pdf file is produced on the remote compile (though it compiles perfectly well on my mac...

fonts sans-serif arxiv math-fonts

sigh

David Z

@JohnRennie well, like I said, it's fine to post on meta about this. (Disclaimer: it's fine with me, but if the community reacts harshly, I'm not going to override that.) Beyond that, you're out of the domain in which the mods have any power.

Shing

Both sites requires a good number of "good guys" to make it great.

the more the better.

David Z

OK, I'm off to sleep, or something... ttyl

John Rennie

@DavidZ there would certainly be no competition between the sites - rather the reverse I would have thought - so the worst I anticipate is disinterest.

Danu

5:27 PM

50

Q: Should zero be followed by units?

Today at a teachers' seminar, one of the teachers asked for fun whether zero should be followed by units (e.g. 0 metres/second or 0 metre or 0 moles). This question became a hot topic, and some teachers were saying that, yes, it should be while others were saying that it shouldn't be under certai...

units conventions notation dimensional-analysis

Perhaps the least interesting HNQ ever?

HDE 226868

@JohnRennie I could have sworn there was a proposal on Area 51 within the past year that got decent support, but it wasn't quite enough. (I'm not saying it couldn't succeed a second time.)

Danu

@JohnRennie Who's going to invest their time in that?

John Rennie

@Danu I would. The question is who else is going to invest their time in that?

Danu

Fair enough :P

You're one of few

0celo7

@JohnRennie I volunteer in 60 years when I retire

Can you wait until then?

John Rennie

5:34 PM

Absolutely. Who else is going to explain how to saw up cerium in a pure oxygen atmosphere at 1700C?

Anyhow, reassured that my idea won't be instantly dismissed out of hand I'm going to settle back with a beer and think about it (for several seconds, then I'll get stuck into my next book :-).

Terry Bollinger

I like the cerium in O2... :)

0celo7

@JohnRennie Not me. Whoever did that is probably dead :(

Shing

what level are those Q?

undergrad?

0celo7

What Q?

Shing

homework question

never mind. I thought you were talking about answering more homework questions.

the chat is kind of too long, I am not sure what is exactly going on here

0celo7

5:41 PM

@JohnRennie I will help you if I can get mod powers

NeuroFuzzy

@Shing Me neither.

Shing

@NeuroFuzzy you are not alone then lol

Anyway, I can help, if it is about needing more people answering homework. but I am afraid I can only help undergrad physics.

btw I am good at EM & CM, but not QM or SM (I can try though)

0celo7

Oh god someone just asked if SO(3) is abelian

How do you know what abelian means but not that SO(3) isn't????

HDE 226868

Ah, here's one incarnation of the idea:

Nov 4 '14 at 16:42, by Kyle Kanos

7

Physics homework questions

Proposed Q&A site for students needing help and hints for physics problems and questions either experimental, conceptual or calculational and people who need help to understand a concept in physics or have questions about some concepts taught in class or physics books.

Currently in definition.

0celo7

Nothing there @HDE226868

HDE 226868

5:48 PM

@0celo7 Yes, I had pointed out earlier that it failed.

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