The h Bar

experimentX

11:28 AM

Hi ... anyone here?

is magnetic force a conservative force?

Manishearth

1:10 PM

@experimentx don't even ask

IIRC it can be either

It does no work on charges, so it can be both. In the case of currents, though, it can do work.

I think

In case of currents/dipoles, IIRC it is conservative.

Manishearth

2:15 PM

Conservative force

A conservative force is a force with the property that the work done in moving a particle between two points is independent of the path taken. Equivalently, if a particle travels in a closed loop, the net work done (the sum of the force acting along the path multiplied by the distance travelled) by a conservative force is zero. A conservative force is dependent only on the position of the object. If a force is conservative, it is possible to assign a numerical value for the potential at any point. When an object moves from one location to another, the force changes the potential energy ...

See the mathematical description, bottom part

Manishearth

3:54 PM

crickets

David Zaslavsky

@Manishearth hey, I'm here :-P

John Rennie

I got a message saying "chat starting now". What are we chatting about? The weather is rubbish here in the UK!

David Zaslavsky

Anything, really

New developments in the world of physics, or anything about the site, or whatever people want to share...

...even the weather...

John Rennie

OK, at the risk of being excessively serious, do we regard the Physics SE as primarily a teaching resource, a research resource, or some mixture of the two. I ask because this affects what questions we allow and how we answer them.

Manishearth

@john in Bombay we're getting intermittent rain, which is bad--the humidity makes the atmosphere oppressive, and the less quantity of rain doesn't manage to cool it down. Arrrrgh

@john Mixture. Note that the primary goal isn't to help the asker, rather it is to help as many visitors as possible

David Zaslavsky

4:00 PM

@Manishearth yeah, that seems accurate

Manishearth

@david I think it's time we use the custom feed user option and have Crickets post all the meta.phy.se questions :P

David Zaslavsky

I'd like to always try to increase the research aspect of the site

@Manishearth hm, I'm ambivalent, you could change that if you like though

@JohnRennie Anything in particular that prompted you to ask?

Ron Maimon

I think it should be a mix, but with an eye to upvoting the serious questions more, and leaving the elementary questions with only a few upvotes. This counteracts the natural tendency of people to upvote stuff that sounds familiar, which is the reason research is difficult--- new things always sound stupid regardless of whether they are right or wrong.

Manishearth

Yeah. More expert qs is good. Too many novice qs, and you scare away the experts. Partially why TP.SE was created--though I don't think we have that many novice qs.

John Rennie

Well, there's the vexed issue of homework questions

Nic

4:03 PM

@RonMaimon I've wondered about the best use of the question votes, this seems like a good idea

Manishearth

@david That was a joke, but we could mess around with the feed user for the heck of it :P

@ron hmmm, I don't really think so, but that's just me.

Nick Kidman

Weather is boring here.

David Zaslavsky

I pretty much always upvote research-level questions

Manishearth

15

Q: When should I vote?

I have seen a few questions here on Meta Stack Overflow that cover parts of this, but they are often too local, and none of them seem to cover all the relevant scenarios. I will break it up into multiple parts in order to make this more specific: When should I vote on a question: ...

^^Shameless self plug

John Rennie

My college used a tutorial system where grad students would sit down with you and go through your work. Sometimes they had to solve the question for you, if it was just too hard, but you'd learn a lot by treating it as a worked example.

Nic

4:04 PM

@JohnRennie I think homework questions can be useful, where there are 'canonical' type questions investigating common phenomena

Manishearth

@Ron Oh, questions. I think we should use the same rubric as with normal questions, basically the "research effort" thing. Of course, most research level questions will probably be of that form..

John Rennie

The recent question about handling acceleration in SR would have made a marvellous blog post, but here it ends up closed and ignored because it's a homework question.

David Zaslavsky

@JohnRennie yeah, exactly. Feel free to turn it into a blog post if you like.

John Rennie

It seems to be that a really thorough article would be interesting reading for anyone interested in learning SR.

David Zaslavsky

This isn't the place for blog posts, though (despite what some other sites are trying to do).

Manishearth

4:07 PM

@david no self answers. Here? :(

John Rennie

@DavidZaslavsky: I don't have a blog, and if I did I would post articles there as no-one would read them. I take your point tht this isn't a blog posts, but many of the answers here are effectively blog posts.

David Zaslavsky

Well, I'm not going to say they're not allowed, but I feel like posting a self-answer is not in the spirit of the site.

John Rennie

I reckon I could make a successful blog by just stealing Ron's more discursive answers! :-)

David Zaslavsky

Oh, I don't know about that :-P

Yes, a lot of answers could become blog posts, but here, they start out as answers. They're things that get written because they are useful to someone else, not because of idle curiosity.

John Rennie

Well yes, but not if we think i's a homework answer ...

Nick Kidman

4:09 PM

btw. I've come to the point where I can know the poster of an answer by the first four words

David Zaslavsky

True

Nick Kidman

anna: "That's an interesting question!" (3 pages follow)

Manishearth

@john You could edit that post to a non-HW and have it reopened.. I think.

Nick Kidman

Lubos: "You completely misunderstood XXX!"

Manishearth

@nick you can tell it's Terry when it's "10 pages follow". He has unleashed himself on chem as well, I just sit back and watch :P

David Zaslavsky

4:11 PM

Basically the idea behind the homework policy is that the vast majority of people with physics questions are students who want an easy route to getting their homework done. It's in our interest to make it absolutely clear that they cannot get that kind of help here, because otherwise, we'll be flooded with homework questions.

Manishearth

@Nick and any thermodynamics post, on Phy or Chem, has a 50% chance that it's you :P

Nick Kidman

you mean question or answer?

David Zaslavsky

Sounds like one could make a cartoon with the different answer styles :-P

Nic

Am I allowed to ask what happened to Georg?

Nick Kidman

Yeah, I can also tell Rons answers from the length to number of bold headlines to seperate sections ration

Manishearth

4:13 PM

@nick I think both. All your qs on chem are thermoD, seen quite a few such qs on Phy as well. I remember you answered my first question on SE :)

Nick Kidman

ratio*

lurscher

hi everyone

Nick Kidman

@Manishearth: Is that so? I hope you accepted it! :D

Ron Maimon

There are a few questions that crop up from time to time that I think are annoying, like anything that doesn't have a positive formulation "what lies beyond the seventh dimension?" etc. I wish there was a way to ask for positivistically meaningful questions right off the bat, although it seems to be happenning anyway.

David Zaslavsky

@Nic you can ask, but I don't actually know... as far as I know he just left

@RonMaimon all we can do is downvote and/or vote to close the bad ones

Nic

4:15 PM

@DavidZaslavsky fair enough. He seemed quite a regular then disappeared!

John Rennie

I suspect many of the questioners are school kids who have just been watching the latest Michio Kaku documentary, and they don't necessarily realise their question is silly.

Manishearth

My answers generally start with a "I have no clue what I'm talking about, comments appreciated" header :P

Colin McFaul

@Nic, I just saw Georg on Chem.se yesterday.

Manishearth

@john yeah. Popsci questions, all from a half-understanding of SR/etc

David Zaslavsky

@JohnRennie true; the thing is, this is meant to be an expert-level site. Not that you have to be a practicing research physicist to participate, but the audience we primarily want to cater to is not people who have only watched a pop-sci documentary.

Manishearth

4:18 PM

@nick you answered in the comments :P

@colin Yep, Georg is alive and well on Chem

David Zaslavsky

@Manishearth @NickKidman never too late to fix that!

John Rennie

I find there is an enormous interest in the glamorous aspects of physics from my non-physicist drinking buddies. I suspect these massively outnumber the practising physicists.

David Zaslavsky

(by the way, PSA: let's try to avoid answering things in comments...)

Ron Maimon

There is an issue with bounties and research level questions. With some questions, like notably "prove that the hammock potential goes to a free field at long distances". One knows the answer immediately, but proof requres a tremendous amount of work, and when you post a proof you worked hard on, get a "+1" or even "+2" (like that ever happens! You usually get +1 for a correct technical post, or sometimes 0 because nobody understands it, or -1 because somebody thinks its wrong)

David Zaslavsky

@JohnRennie Probably true.

Ron Maimon

4:20 PM

When I answer in comments, I usually vote to close. If the question can be answered in comment, this means that the question isn't really up to snuff.

David Zaslavsky

There are places like Reddit's /r/askscience and Physics Forums which are better locations for the pop-sci-type questions.

John Rennie

My point is that whether we like it or not, a large number of site members will be looking for something like the popsci programmes but with greater depth.

Nic

@DavidZaslavsky +1 to that

Ron Maimon

Anyway, regarding the bounties, Erdos used to give actual bounties for proofs, and made them permanent. I think that a permanent bounty is a useful thing, to make hard research problems worth answering and give them attention.

David Zaslavsky

@JohnRennie Well, now, what do you mean by greater depth? That might be what makes the difference between a good question and a too-elementary question

@RonMaimon yeah, I believe you can do that with bounties

lurscher

4:22 PM

can you? i thought bounties were always of one week of duration

Manishearth

@ron in this case, it was answered in a huge back-and-forth between me and Nick. It may be worthwhile for me to go back and incorporate all my comment clarifications to the question

John Rennie

Well for example I think we can do a lot to improve understanding of GR beyond the ball rolling on a rubber sheet analogy, and I think a lot pf people are interested in this.

Manishearth

@david remember that there's the advertising side of bounties. Just like an ad company won't let you keep an ad up till you get results, ithe duration is always fixed.

@john Eg me. Though I'll have it in my second year, and I probably won't have the time to teach it to myself now, so I shall wait.

David Zaslavsky

@lurscher I think you have to wait a week to award it, but you can definitely place a bounty with the intention of rewarding a specific, existing answer

Ron Maimon

I think this site should just answer nontrivial questions correctly. That automatically makes it different from pop-sci on say, television, which creates fictional questions that nobody really asks and answers them incompetently and sensationalistically.

Nick Kidman

4:25 PM

We should introduce a female quota

Manishearth

@nick ?

David Zaslavsky

@Manishearth this is true. Though personally I'm not such a fan of that use of bounties, since the one time I used one it was ineffective.

twistor59

Upvote for Nick's suggestion

Manishearth

Similar discussion that a CSE mod had pointed out:

0

Q: Females on Christianity.SE

I have this feeling that this site is male dominated which is normal but I think women patronage is too low if I'm right. First of all I'll want to know the ladies currently using this site. Let's acknowledge them. And if anyone agrees with me, let's put up something that attracts the ladies to a...

discussion users

David Zaslavsky

@twistor59 (star?)

John Rennie

4:27 PM

I think the site should answer all questions correctly. OK some questions will be so trivial you can't do anything useful with them, but an apparently trivial question may simply mean the OP doesn't know how to phrase their question properly.

Manishearth

@david yeah, it's much more useful on SO.

Ron Maimon

John; I agree--- I meant you don't have to answer "How many joules is an eV".

Manishearth

@john that's what comments are for--clarification.

David Zaslavsky

@JohnRennie This is where the close-edit-reopen cycle comes in

Manishearth

That too

Ron Maimon

4:29 PM

I don't like "close edit reopen" too much--- it's not a cycle in practice, only in propaganda. It's just "close the idiotic or repeat questions by political sledgehammer" (which is useful to some extent, don't get me wrong), but call it by its proper name--- a smack on the cheek.

John Rennie

@RonMaimon: <grin/> Mind you I answered someone who asked how to convert the Higgs mass to kg, and got a dozen upvotes for it!

David Zaslavsky

@NickKidman Seriously though, if there is something keeping women off the site, then it would be great if we can do something about it

John Rennie

I agree with Ron, when a question is closed that feels like it's in the dustbin.

David Zaslavsky

@JohnRennie It shouldn't. That's not the purpose of closing.

Well, not always... admittedly in some cases a question is just beyond repair, and then it should feel like it's in the dustbin.

Ron Maimon

That's only propaganda. That's what it's for, but nobody is allowed to say it. In practice, what fraction of closed questions are reopened? I would guess 1 in 20.

Colin McFaul

4:31 PM

When it gets reopened, it shows up again at the top of the recently modified questions.

twistor59

@DavidZaslavsky I think if I were new to the site and got my first question closed, I would be disheartened

Manishearth

My policy on chem is to comment on posts I close, and include a "if you can edit it so that blah blah, I'll be happy to reopen it".

2

Ron Maimon

Why not wait to close then until the edits are not made?

John Rennie

The only, and therefore presumably intended, effect of closing a question is to stop anyone from answering it. That seems to me like saying "this question isn't worth answering".

David Zaslavsky

@JohnRennie And when a question is closed, it's true that in its current form it's not worth answering. That's why it gets closed.

Colin McFaul

4:33 PM

How long should we wait for the edits to not be made?

lurscher

that is the best you can do. also if the person does a meaningful edit it proves that he cares somewhat. i think close a question is like a test, if you dont pass it, probably there was no much good in the question anyways

Ron Maimon

David, we know the party line, that's not the practical impact of closing.

David Zaslavsky

@RonMaimon you can't wait until something doesn't happen

Ron Maimon

Yes you can. Use common sense.

David Zaslavsky

Common sense says you can't wait until something doesn't happen.

Ron Maimon

4:34 PM

I sometimes just make the required edits myself, and ask the OP if this is ok.

lurscher

the close is more like 'are you willing to put a bit of extra effort in the question, and we'll reopen'

2

Manishearth

Damn, gtg. Talk to you folks later.:)

David Zaslavsky

@Manishearth See you later

Ron Maimon

I disagree. This is not how closing works on other sites. The purpose is political sledgehammering. It is wrong to say something is for one purpose, when in practice it is a political tool of shutting people up. You need to shut people up.

David Zaslavsky

@RonMaimon Well, it's how it's supposed to work.

twistor59

4:35 PM

As a matter of interest, approx what fraction of closed questins DO get reopened?

Ron Maimon

I don't agree. How it works is how it works.

David Zaslavsky

@twistor59 I can try to figure that out

Most of the ones that get edited by the OP do get reopened.

Ron Maimon

On other sites, like philosophy, it's around 1-5%. I know, because I have questions on non-physics sites closed like crazy.

Why not just make an edit yourself and ask OP for permission?

Colin McFaul

In some cases, I agree that that is a good idea. In some cases, I can't figure out what the OP is even trying to ask.

Nick Kidman

Philosophy.SE is terrible

Ron Maimon

4:38 PM

Well, then, slap the OP! But be aware it's a slap.

twistor59

@ColinMcFaul yes, some require instant dismissal, but some are redeemable

Ron Maimon

phil.SE is terrible in the exact same way academic phil is terrible.

twistor59

@RonMaimon "slap" icon required

David Zaslavsky

hm, it got quiet suddenly...

lurscher

@RonMaimon, the problem with editing yourself is that it does not help the OP in most circumstances. People need to make a conscious effort to try to do better questions

moderators should not be question nannies

i mean, they sometimes could do that

but they should not be expected to do it every time

the ball should be on the OP

thats is my opinion

Colin McFaul

4:47 PM

it's also a repeated game. If a uses never learns how to ask a question, then we'll always need someone else to edit their questions for them.

making them rewrite it themselves helps them learn how to ask a question.

twistor59

Hmm I was just thinking: do we want to increase site traffic? Is that the aim? in which case a more gentle close policy would be appropriate. Or do we want to increase the mean quality? In which case the reverse would be true.

David Zaslavsky

@twistor59 I'd say quality is more important. Yes, we want to increase traffic, but not at the expense of question quality.

By the way 8% of closed questions get reopened.

twistor59

@DavidZaslavsky I would too. I think it's the quality that really distinguishes this site from, for example, physicsforums, where there's a lot of drivel discussed. Ah 8% - interesting. I would say that doesn't sound too bad - that sounds like about the right number of rescuable questions that you'd expect, no?

lurscher

we want to increase the traffic, but not any traffic, we want to increase the amount of qualified traffic

if there is no quality, the traffic will be irrelevant

3

David Zaslavsky

@twistor59 yeah, could be worse. It's kind of piqued my curiosity - I want to check into the editing statistics of these posts now.

or, well, later :-P

Anyway, while we're all here: a quick reminder about tag cleanup efforts which are still ongoing

(I know I forget about this just like everyone else)

twistor59

4:53 PM

@lurscher I think part of the problem is that quality people are sometimes too embarrassed to ask questions for fear of looking dumb

2

lurscher

yes that is a problem

David Zaslavsky

@twistor59 this is true, which is why I always try to leave happy helpful comments on questions that I close

2

Q: Tag cleanup--[light]

Chat link, Another one I'm currently retagging all questions tagged light to visible-light and/or electromagnetic-radiation Since editing them all at once will flood the main page, I'll keep track of them here, and slowly work my way through them. Feel free to help! (try to do maximum 5 at...

discussion cleanup

8

Q: How should we go about retagging the salvaged posts?

UPDATE from D.Z.: I'm hijacking Manishearth's question to organize the tag cleanup effort, because most of the links are already posted here. Here's how this is going to work: whenever you have time and feel so inclined, go through the lists below and pick out a few questions (maybe no more than...

discussion site-salvage retagging

interesting, apparently a query string prevents oneboxing...

So, interesting developments in the world of physics?

When we had our last chat session the discovery of the Higgs boson had not yet been announced

twistor59

I must go and hit the road now. Before I go, though, I'd just like to point out that I think this is an extremely useful physics resource. There is information available here that's very difficult to find anywhere else, at least in this form. So although we're talking about improving things here, it's not like it's grossly broken - from my POV it works very well.

Bye for now

David Zaslavsky

@twistor59 good to know some people are happy

Bye!

This reminds me: we could do a community self-evaluation or whatever it's called... on some other sites, what happens is we the community team picks a random selection of recent questions and we check whether the information in the answers is better, on par with, or worse than what you get from Google

It may help identify ways we can improve the site

Anyway, our hour is (past) up, so thanks everyone for participating! See you back here in two weeks! (Or earlier if you like)

Nick Kidman

5:16 PM

In the StackExchange FAQs it says most traffic should come via search engines, but stack exchange never comes up if I google something.

Also, somehow the tag button to see related tags doesn't work for me (for at least several months), somebody knows why?

David Zaslavsky

@NickKidman huh, not sure

Can you make a meta post about that, with screenshots if possible?

@NickKidman regarding Google... honestly, only Stack Overflow itself has the clout to appear near the top of search results for most common searches in the subject area, and even then, not always

However we do get a majority of our traffic from Google, according to the site analytics

Nick Kidman

this is what I get when I click any tab

heat in that example

Manishearth

Btw, I have a script that lets you vent on other users harmlessly

Would that count as a slap?

Nick Kidman

vent?

Manishearth

1sec

github.com/Manishearth/Manish-Codes/blob/master/StackExchange/…

Nick Kidman

5:29 PM

tl;dr?

Manishearth

Use Raw link on chrome (or FF with greasemonkey) to install

Nick Kidman

wat does it do?

Manishearth

Adds a "punch user" button.

Nick Kidman

... not gonna ask any furthere

Manishearth

The button summons Commander Keen, who attacks the user for you on your screen :p

Nick Kidman

5:31 PM

(that rimes)

I write poems.

about physics too.

Manishearth

Cool! Havr any good ones? :D

Nick Kidman

Sure. Not english though

Manishearth

Kk. :\

What do you do, exactly? (research topic/etc)

Nick Kidman

I'm a rapper

Manishearth

Really? Nice :)

Thermodynamics is just a hobby?

Nick Kidman

5:39 PM

I find it funny that you associate me with thermodynamics.

I'm going to brows and see what are my most answered/questioned topics

Manishearth

Well, that's where I've seen you :)

David Zaslavsky

@NickKidman ah, I see

Try this: click on "QUESTIONS" and then select "newest"

Nick Kidman

28
quantum-mechanics × 19
10
general-physics × 3
18
mathematics × 3
9
soft-question × 9
12
thermodynamics × 13
9
quantum-field-theory × 7
10
temperature × 6
7
special-relativity × 4
10
spacetime × 4
7
gauge-theory × 3

David Zaslavsky

The site remembers whether you're browsing newest or featured questions (or some other category)

Nick Kidman

ah, works thanks ;)

Manishearth

5:41 PM

@nick hmm, why have I not seenyou post on the other tags? :p

David Zaslavsky

Cool :-P and I just noticed you can also just click on "newest" above the tag wiki excerpt (in case it ever happens again)

Nick Kidman

@Manishearth: I don't know, neighter of my most rated question in answer or question on my profile pic have to do with thermodynamics

Manishearth

Strange :S

Nick Kidman

I actually like to view profiles

Manishearth

:)

David Zaslavsky

5:44 PM

By the way, some statistics in case anyone's interested: (if my query is correct) there are 802 instances of questions being closed on this site. Of those 43 were edited and reopened, 28 were reopened without editing, and the remaining 731 were never edited and never reopened.

...though looking at that, I'm not sure it is exactly correct... still, probably roughly accurate.

Nick Kidman

what is the number here, 74.3k for example?

AlanSE

hiii

David Zaslavsky

@NickKidman if it's the number I think you're thinking of, it's total reputation across the network

Nick Kidman

you missed the party

David Zaslavsky

@AlanSE hi :-)

Manishearth

5:46 PM

Hey there :)

Nick Kidman

I think it's all the reputation you ever got or something.

AlanSE

oh wow, this was a hot chat at noon when it was supposed to start :-P

Nick Kidman

what?

Manishearth

@nick yep. The network flair shows sum of all rep on sites where rep >200. Chat rep is sum of all rep, period. Chat badges are parent site badges

Nick Kidman

@AlanSE people were talking about how to improve the site quality and when to close and reopen questions. No solution was found, but problems were estabished

network flair?

AlanSE

5:50 PM

okay then... good talking with you all

Manishearth

I find it strange that one can get 10k chat privs (view frozen/deleted rooms, handle spam/offensive flags) pretty easily--earn some rep on one site, create accounts on all 81 sites and use the assoc bonus

@nick profile>flair

Nick Kidman

fun fact: 1 \in (0,3), where (0,3) is the ordered pair containing the numbers 0 and 3.

Manishearth

@nick this is a per-site flair:

David Zaslavsky

@AlanSE see you later

Manishearth

This is network flair:

(pay no heed to the username)

@alan cya

Nick Kidman

5:53 PM

ManishEarth wants more what?

experimentX

Hi

@Manishearth what is IIRC

Nick Kidman

Hi Experiment

experimentX

Hi NickKidman

Nick Kidman

fun fact 2: quotes: ITER was originally an acronym for International Thermonuclear Experimental Reactor, but that title was eventually dropped due to the negative popular connotations of the word "thermonuclear", especially when used in conjunction with "experimental".

2

David Zaslavsky

@experimentX IIRC = "if I remember correctly"

experimentX

5:57 PM

oh ..

Nick Kidman

Have you heard of the paper, that shows that there is no solvable 16-clue sudoku?

experimentX

all right thanks ... guys

Nick Kidman

cu

Manishearth

@nick waffles. One of the devs, whose username was waffles, left. This was to acknowledge him. (keeps in tune with the waffle meta meme as well) , Network flair copied over the most-recently-changed username :/

experimentX

cu

Manishearth

6:06 PM

@nick hmm, nope. Sounds interesting

Nick Kidman

fun fact 4:

some of my favorite (paper) titles

>Hodge's general conjecture is false for trivial reasons
>You Could Have Invented Spectral Sequences
>A minus sign that used to annoy me but now I know why it is there
>How not to prove the Poincare Conjecture
>Ramanujan's association with radicals in India
>Is the null-graph a pointless concept?
>Everybody knows what a Hopf algebra is
>On O_n
>Free rings and their relations
>Six standard deviations suffice.
>The importance of being straight
>The homotopy category is a homotopy category

2

(math papers, that is)

Manishearth

Ima gonna google those when I have time :P

I know of the monster group, tho :)

Nick Kidman

but do you know...

(pic out random interesting group)

Rubik's Cube group

In the mathematics of the Rubik's Cube mechanical puzzle, the Rubik's Cube group is a group that corresponds to the set G of all cube moves on the Rubik's Cube with the group operation • being the concatenation of cube moves. With the solved position as a starting point, there is a one-to-one correspondence between each of the legal positions of the Rubik's Cube and the elements of G. Cube moves An original 3×3×3 Rubik's Cube consists of 6 faces, each with 9 colored squares called facets, for a total of 54 facets. A solved cube has all of the facets on each face having the same color....

Manishearth

Ah, that one. I know nearly nothing in group theory, but some digging on a question of mine did reveal thr Rubik group

must learn group theory

Nick Kidman

I see

(and it's cute that you think one can just write down the order of the monster group in decimal notation ;)

regarding rapping, I love the song "Simple Group (of order two)"

Manishearth

6:16 PM

OIC, that's only a baby monster :p

Hmm, will check out.

Nick Kidman

►

Manishearth

Not now, though. On mobile at night, dont want to dig for earphones

Bokmarked :)

Nick Kidman

Is there a reasonable idea why SU(3) worked out for QFT? Is there something special about that group?

(no pun intended)

David Zaslavsky

:-P

You mean for the strong interaction? I don't know that there's anything particularly special about it. As far as I know it could just as well have been, say, SU(4). But I'm not 100% sure.

It just turns out that SU(3) matches reality.

Arnold Neumaier

SU(3) was small, hence easy to discover. Easier structure tends to be found earlier.

Nick Kidman

6:27 PM

@ArnoldNeumaier yes, that's true, but by now people have investigated groups like blabla32 in detail, right?

Or let's put it another way: Is there a reason not to think more bosons would be reasonable to show up?

Arnold Neumaier

yes, but verifying SU(5) or SO(10) (which might be grand unification groups) is a much harder job than verifying SU(3),

and at lower energy there are fewer particles, hence only smaller groups are easily visible.

Nick Kidman

mhm, yeah, I guess I'm okay with a "this is what we are capable of handling and good if it works" argument

Nick Kidman

7:23 PM

Is the parameter t in (q(t),p(t)) in \Gamma of statistical mechanics always taken to be the time? Or do people also use the whole formalism for some structures which are pretty different from the mechanics framework. After all, I think peole say that all the things don't really depend on the equations of motion, they only want some ergodic principle to be justified.

kηives

10:48 PM

I quite naive about coupling theories together, and even more about unification, but could SU(5) coupled to LQG possibly change the proton decay rate for the better? i guess a similar question is could SU(5) on a lattice affect the proton decay rate?

I'm*

Transcript for