The h Bar

12:12 AM

I exactly agree with what Qmechanic says about the different kinds of metrics, that the spacetime metric is not the only one useful and used in physics. And yep theoretical physics can be quite mathematical, nothing bad about this ;-)

tpg2114

2:53 AM

Since I'm in that in-between stage where I can retag questions without verification but can't edit questions without verification, is it better (on new questions) to retag and then edit? That way at least the retag is visible until the edit is accepted...

David Zaslavsky

Yeah, I guess that seems right

tpg2114

@DavidZaslavsky I don't know enough about Ising spins to know whether questions on visualizing them would be on-topic or not (obviously software-recommendation isn't)

It looks like it's just a graph of +1/-1 designating spins?

David Zaslavsky

Yep

Ising model

The Ising model (; ), named after the physicist Ernst Ising, is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables that represent magnetic dipole moments of atomic spins that can be in one of two states (+1 or −1). The spins are arranged in a graph, usually, a lattice, allowing each spin to interact with its neighbors. The model allows the identification of phase transitions, as a simplified model of reality. The two-dimensional square-lattice Ising model is one of the simplest statistical models to show a phase transition. The Ising...

The topic is definitely physics-y enough to be on topic here

tpg2114

But the concept of "visualize a graph with a variable at each node" isn't at all, and that's all this boils down to it seems

It doesn't matter what the variable is per se

David Zaslavsky

Good point

tpg2114

3:07 AM

I could be missing something about how visualization might help study the results that only physicists might know

David Zaslavsky

I guess this is part of why recommendation questions are off topic, that you can often reduce the requirements to some other set of requirements that have nothing to do with your site

@tpg2114 it's possible. Ising models are not my specialty, and so I wouldn't know, but I imagine there are programs which can display various computed parameters based on the states of the spins

And perhaps even evolve the spins over time according to some specific model

tpg2114

That's possible, but those wouldn't fall in the visualization category, at least in my book. I think closing that question was correct, but I'm still not sure how I feel about software questions in general

David Zaslavsky

Oh, indeed, I do agree that that question was appropriate to close

tpg2114

Are you enjoying the lovely PA winter weather by the way?

I grew up outside of Philly, almost everybody from my school ends up at PSU. I went south to get out of the crappy winters

David Zaslavsky

Well, I'm at home with my family, so it's upstate NY winter weather, but yes, very much :-)

I actually like this kind of weather

I want my winters to have proper amounts of snowfall

tpg2114

3:13 AM

I'm at Georgia Tech... Atlanta weather is much more my style

David Zaslavsky

Fair enough ;-) I guess it's pretty nice there this time of year?

tpg2114

Comparatively yes. It was in the 70's up until last week... We had severe storms, tornados south of us, last night

Now it's 25 and windy, but it will only last a few days and get back up to 50's/60's

David Zaslavsky

ick :-( 25 Fahrenheit?

That's colder than it is here...

tpg2114

We usually get one bad winter storm... last year we had a storm in Jan that dropped about an inch of ice

And the 3 snow plows for the state of GA couldn't keep up, we were iced over for like 2 weks

David Zaslavsky

wow

Of course an inch of ice is nothing to sneeze at, even in the northeast

tpg2114

3:17 AM

Yeah, ice is way worse than snow.

That's usually what happens here, we rarely get snow but ice storms happen each year

I've been down here 8 years now... I don't miss snow, that's for sure

David Zaslavsky

No complaints about that, it means more for me ;-) lol

Actually it hasn't even snowed much recently, not that I can remember anyway. This storm we're having right now is one of the biggest in a few years

tpg2114

Yeah, I think two years ago there was another big one, at least in SE PA

This was the first year I didn't go home... My mom wasn't happy, but I managed to avoid the crappy weather at least

David Zaslavsky

Kind of worked out, in a way

tpg2114

I thought so...

1

Q: Element of area in 4-dimensional space-time

How would you proof that $$ \mathrm {Tr} (\mathbf{S\cdot \bar S })=0$$ where $\mathbf S$ is an element of area delimited for the 4-vectors $\mathbf u$ and $\mathbf v$ given by $$S^{\alpha \beta}\equiv u^\alpha v^\beta-u^\beta v^\alpha$$ and $$\bar S^{\alpha \beta}\equiv \frac{1}{2}\epsilon^{\alp...

Does that fall under homework too?

David Zaslavsky

Hmm... well, I can see the argument for saying it would, but I wouldn't put that tag on it. It just doesn't read like a homework question to me

tpg2114

3:23 AM

I didn't think so either, but it also seems like something that would be in a textbook somewhere

David Zaslavsky

Could be, but I could also see it coming up in a different context - maybe the OP wants it for research, or is just curious.

When it comes to applying homework, it's hard to define exactly what reads like a homework-like question, but you know it when you see it, once you've seen enough of them

tpg2114

Yeah, usually any time a number appears... or "Please help!"

David Zaslavsky

Well those are the obvious ones ;-)

tpg2114

It could be a full-time job just policing/editing questions

David Zaslavsky

yeah

this is why I've wasted so much time on this site ;-)

tpg2114

3:32 AM

Me too... rep is hard to earn 2 points at a time though

While waiting for fluid dynamics questions to come through

David Zaslavsky

yeah... I feel like there could be a lot more good fluid dynamics questions on the site, but I don't know how to encourage people to ask them

tpg2114

Maybe it's just not that interesting to the people here. Not all of us can like everything :)

David Zaslavsky

3:47 AM

True. But that just means we can use more people who are interested in fluid dynamics :-)

tpg2114

It's interesting to watch the evolution of people doing work who need help:

0

Q: Calculational method for determining surface tensions from photograph of menisci?

How can I get from a photograph of a liquid surface to a value for the surface tension.

optics fluid-dynamics experimental-technique

1

Q: Why does water make a liquid film?

Cut a narrow slit in a thin sheet of opaque material. Immerse the sheet in a liquid, such as water. After removing the sheet from the liquid, you will see a liquid film in the slit. The question is: why does water make a liquid film and not stay where it was originally?

fluid-dynamics surface-tension

-3

Q: In my experiment what kind of formula will be written?

Cut a narrow slit in a thin sheet of opaque material. Immerse the sheet in a liquid,such as water. After removing the sheet from the liquid, you will see a liquid film in the slit. Illuminate the slit and study the resulting pattern. In my experiment what kind of formula will be written? mg=2Fs i...

fluid-dynamics surface-tension

"How do I measure", "Why does it happen", "How do I model"

David Zaslavsky

Yeah... no complaints here though

well, if the questions are good

They probably look at me the same way on scicomp.SE

tpg2114

I jump from SciComp to Stats to here enough that it's harder to track my work progress :)

David Zaslavsky

Somebody should write an app for that (lol)

Of course there's always this

tpg2114

I can't tell you how many times I've seen a question on one of those three sites and go "Oh, I can answer that!" and it turns out to be from somebody working downstairs in my lab...

David Zaslavsky

3:59 AM

@tpg2114 cool :-)

Exactly once, I think, I've seen a question posted by someone I know

tpg2114

stackexchange.com/users/343965/frenchkheldar

He works downstairs

David Zaslavsky

4:25 AM

nice

David Zaslavsky

4:36 AM

@tpg2114 Sorry to run off, I got busy... nice chatting with you though :-) Good night!

tpg2114

Have a good night!

Physics Meta

6:20 AM

0

Q: Are community members disciplined over abusing other community members elsewhere using links to this site?

Suppose a community member uses another site to abuse another community member, but using links to this site, such as to posts and profiles etc. Should that member be brought to the attention of the moderators?

discussion

Sklivvz

9:52 AM

0

A: Are community members disciplined over abusing other community members elsewhere using links to this site?

I think you should absolutely report it, but keep in mind that, as David says, mods can only take action for whatever happens on the site and not for what happens outside. That said, it is obvious that people having arguments off-site is likely to have consequences on-site, and any warning is us...

I have no clue whatsoever why @david and @manish would discourage people from trying to help... :-/

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