The h Bar

0celo7

12:18 AM

@FenderLesPaul watcha up to

DanielSank

Are list questions allowed?

I've never been clear on this.

The question which caused me to ask is this one.

ACuriousMind

@DanielSank Old meta discussion is here

They waffle a bit around the topic, but I believe by now it is somewhat consensus that list questions are disallowed - leaving a comment "This seems like a list question" and voting to close as too broad has never really gotten any disagreement that I would have noticed.

Stan Shunpike

12:33 AM

That was my understanding as well

@ACuriousMind

ACuriousMind

There's also this in the dont-ask page: "your answer is provided along with the question, and you expect more answers: “I use ______ for ______, what do you use?”"*

The question you linked already presents a way to solve the problem.

I now anticipate that you will point out that one could avoid that point by essentially making the question worse by omitting the method cited, @DanielSank ;)

DanielSank

12:59 AM

@ACuriousMind Well, yeah. Criteria which can be subverted by removing information from the question are bad criteria.

ACuriousMind

1:36 AM

25

Q: What should be a formal greeting when you meet someone in a toilet?

Assume the following situation. You're in an office in Vienna. It's time around lunch and normally one greets each other with "Mahlzeit". You go to a toilet and suddenly meet your boss there. How should one properly greet in such situation (as you can't just silently ignore him/her)? Most of usu...

SE truly is a wonderful place.

0celo7

haha German.SE

...I've never greeted anyone with Mahlzeit...

ACuriousMind

The questions about Du vs. Sie are also funny, especially when they have to state there's this range where neither knows what to call the other and both just awkwardly dance around it :D

0celo7

While keeping silent, nod your head and smile (but not too much). :) — Daniel Jan 30 '14 at 15:48

ACuriousMind

@0celo7 It's more common in the South, and also mostly with working people around lunch

0celo7

Well I did not work in Germany and was not in the South, so...

You should get BF4.

Just throwing that out there.

ACuriousMind

1:42 AM

Not much of an FPS player, remember?

0celo7

Yes, but I need more people who play BF4.

Everyone at home is LoLing all the time.

And most of my old BF3 buddies are still on console or have moved on.

I think Hardline killed a lot of fans.

Wow. Dr. Feire's homework: 3., 4. (a), (b)

no page

nothing

0celo7

2:01 AM

@KyleKanos what's up? (or down)

Kyle Kanos

Moving soon :)

Thursday soon

0celo7

damn that's quick

you ready to be quantized?

I'm ready

NDA and everything?

Yep

2:03 AM

how much can you say?

can you even say that?

Kyle Kanos

Well I'm surely not allowed to give specifics

I can't discuss company policies, procedures, markets, sources, decisions and a host of other business related things

Not sure that I'd ever discuss that sort of thing with not-coworkers

0celo7

Not sure that I'd want to hear that either

But can you tell us, in loose terms, what you are quantizing?

Kyle Kanos

I'm not actually quantizing anything; I'm a quantitative analyst.

0celo7

quantizing = quantitatively analyzing

Kyle Kanos

The business world just abbreviations quantitative analyst to quant

0celo7

2:13 AM

I know.

So do you have a rough idea of what kind of data you will be working with?

Kyle Kanos

Loan rates

0celo7

That does not sound appealing tbh...but you enjoy that kind of stuff?

Kyle Kanos

There's stochastic calculus, algebra & statistics involved

And a bit of programming

So it's some pretty cool stuff

0celo7

Stochastic calculus has always seemed mysterious to me

Kyle Kanos

Fortunately, one is often trying to eliminate the stochastic part (either by taking an extra derivative or making assumptions of the variables such that it cancels entirely) so the "random" bit is rather minimal

0celo7

2:24 AM

Taking an extra derivative?

Kyle Kanos

Well yeah, it's all PDEs with some Brownian noise

But I'm no expert on it, still working through some of the kinks

Probably should prioritize that over GR :/

0celo7

Lol you're reading GR?

Kyle Kanos

I've still not completed Ch 7 of Franklin's book (Schwarzschild metric)

Physics Meta

0

Q: Why are questions or answers allowed to be down voted without comments?

As a middle aged newbie on this site at first I was enthusiastic about it. I studied physics years ago and wanted to refresh my understanding and learn more and maybe even contribute to the community here. Than I noticed it is very common that answers and questions are allowed by the system to b...

feature-request

obe

@PhysicsMeta ::gets down voted without comment::

Kyle Kanos

2:40 AM

I downvoted & commented

Anthony

I have the dumbest question.

Why do surfaces only exert normal forces?

Just because?

Kyle Kanos

This question might be useful to you @Anthony:

2

Q: Normal force: up or down?

The normal force obviously always has direction perpendicular to the surface of contact, but I'm a bit confused about its sense: is it going 'up' or 'down'? I've seen articles on the web that describe the normal force as going either way. My own reasoning would tell me that since force of fricti...

classical-mechanics forces

Anthony

I think I have a different problem- If a ball bounces at a table at an angle, why is it that the table cannot just push back at the ball at that same angle?

Kyle Kanos

Well what's normal to a flat surface?

Anthony

Not an arbitrary angle- but again why are surfaces required to exert forces in normal directions? Did that question really answer that?

Kyle Kanos

2:49 AM

Well think of the symmetry

Anthony

Oh, I'm probably thinking about this backwards. We more or less define surfaces to exert normal forces.

Thanks for putting up with me lol

Kyle Kanos

3:07 AM

Hmm, this seems excessively harsh to me:

GNU is a three-letter self-referenced acronym meaning: GNU's Not Unix. STFW ! (Search The F***ing Web!) — perror 7 hours ago

user54412

3:36 AM

So I always thought pronouncing the thing "ga-nu" was just CS types diplaying some sort of mass illiteracy. Turns out it was the illiteracy of some 80s kids show producers behind it all.

Kyle Kanos

3:48 AM

I've heard some people pronounce it "ga-nu", I say it "gnu"

obe

4:43 AM

where is everyone.

Stan Shunpike

8:17 AM

@ACuriousMind So building off our discussion yesterday, what then is a "gauge field"?

John Duffield

12:06 PM

@dmckee : there's crystal clear evidence that there's inappropriate voting being directed at me. I refer to the hard scientific evidence and to the papers, and I get downvoted, see for example this. This is not a case of "many people think I'm wrong". It's a case of malice from people who don't know as much physics as me, and can't bear to be corrected.

ACuriousMind

@StanShunpike Ah, that is...an interesting question! In our discussion so far, there is no need to have "a gauge field".

In fact, in the generality of "superfluous coordinates" I've spoken of, there is no such that as a gauge field, in general.

The significance gauge field arises from the need to construct a gauge-invariant action: The motivating case is that we have one field which transforms under a gauge transformation as $A \mapsto A + \mathrm{d}\chi$, and some other matter field $\psi$ that transforms as $\psi\mapsto\mathrm{e}^{\mathrm{i}\chi}\psi$.

We want to write the kinetic term for the matter field. If it's a scalar, that would just be $\partial^\mu\psi\partial_\mu\psi$. But if you now do the gauge transformation, and the $\chi$ is not constant, the product rule hits us and the kinetic term is not invariant!

John Duffield

@ACuriousMind : I'm afraid Bosoneando doesn't understanding electromagnetism and is "clinging to ignorance". Google on Duffield Bosoneando Stack Exchange for examples.

ACuriousMind

Therefore, to restore gauge invariance, one must make these terms somehow "vanish". It turns out that the correct way to make them vanish is to replace $\partial_\mu \mapsto \partial_\mu - \mathrm{i}A_\mu$ (don't hold me accountable for the sign! ;) )

In this way, the gauge field $A$ appears in every derivative of fields that transform under the gauge transformation. Even if you had not started with $A$, but only with the transformation of $\psi$, you would have had the extra terms, and would have to introduce something to cancel them to get an invariant action. That something would've been exactly the gauge field $A$ again, and the transformation law $A\mapsto A + \mathrm{d}\chi$ follows then from the form of the terms we want to cancel.

@KyleKanos It's ad nauseam, not ad nauseum :P

Rigor

12:28 PM

rigorously speaking, of course :P

ACuriousMind

@Rigor Your face! I like it! :D

Rigor

Thanks master.

I'm trying to crop it at gravatar

Danu

@KyleKanos What company are you working for?

Rigor

Are you the CIA :P

Amazing, even the mini OED misspelled it @ACuriousMind

ACuriousMind

OED?

Rigor

12:37 PM

Oxford English Dictionary

ACuriousMind

That I cannot believe :P

Rigor

They spelled it as ad nauseaum at the top of the page and then spelled it correctly in the definition entry

Danu

@Rigor That's terrible.

Rigor

It's only the minidictionary

But still...

...finding typos in the OED is rare.

Danu

@Rigor This is really awesome

0celo7

12:46 PM

Your avatar is not rigorous enough

Rigor

My master should be given all the credit. @Danu

ACuriousMind

@Rigor He linked the Euclid game, in case you can't see.

Your master has nothing to do with that.

0celo7

This master thing is going to get old :P

ACuriousMind

@0celo7 Yes, I am going to get old, not even I can stop the passing of time :P

Rigor

Yes master

Darth vader - yes master!

►

0celo7

12:54 PM

@ACuriousMind Do your thesis on aging.

"Spacetime topology in string theory"

Kyle Kanos

@ACuriousMind Same thing

0celo7

(I'm not kidding, doing HE style work in string theory would be amazing)

Rigor

0celo7

ANTS

DUDE THERE ARE ANTS

Rigor

:D

18 mins ago, by Rigor

...finding typos in the OED is rare.

We should saviour this moment.

0celo7

1:04 PM

Omg are there ants reading the dictionary

ACuriousMind

What ants?

0celo7

Put on your glasses!

ACuriousMind

Do you mean the black dots in the background that are probably part of the pattern of the table?

0celo7

No, they're ants.

Rigor

The specks on the desk.

ACuriousMind

1:05 PM

I see you have been training an ant army. Very good, Rigor, I shall use their power to invade the food storages of my enemies!

Danu

@Rigor Savor?

ACuriousMind

@0celo7 I have no idea if such a thing is possible

yuggib

Well OED is not and never will be a reliable source for latin...

Rigor

@Danu sorry I went with auto spell :P

Danu

How ironic ;)

Rigor

1:08 PM

13 mins ago, by Rigor

Darth vader - yes master!

►

Raider fans love darth

He's our leader of the dark side of sports

0celo7

@ACuriousMind Duh, that's why it's called research :P

ACuriousMind

:O

yuggib

Quidquid id est, timeo britannos et latinos vocabulos scribentes

ACuriousMind

mind = blown

0celo7

What does a MS thesis have to be at UH?

Research or a review or what?

Causality in String Theory

You know you want to do it

ACuriousMind

1:14 PM

Something like research

0celo7

@yuggib I recognize those words...

Trouble is, I learned Latin in Germany, and my German isn't 100% anymore :(

Rigor

@yuggib what is the most reliable source?

0celo7

So the L -> G -> E chain isn't great

@ACuriousMind I haven't seen you come up with any bright ideas...

I've given you two ideas.

ACuriousMind

D'oh

0celo7

I agree with some of that.

ACuriousMind

1:17 PM

I wanted to edit, not delete :D

Rigor

Lol

0celo7

Tsk.

ACuriousMind

@yuggib Oh god, my Latin is rusty... "Whatever it is, I fear the Britons, even when they write Latin words"?

0celo7

Idget what the "whatever it is" means

Rigor

You should fear us.

ACuriousMind

1:19 PM

@0celo7 It's a bit awkwardly phrased because @yuggib just modified a famous quote :P

Rigor

We are THE nation.

0celo7

so is "et" "even when"

I thought it was "and"

or does that thing out front modify

the other option is to tell me to go home

I'm bad at Latin

Rigor

English is tough

yuggib

@ACuriousMind Exactly, quoting Laoocon in Virgil's Aeneis ;-)

ACuriousMind

@0celo7 et can mean "and", but it is also able to mean "also, even"

0celo7

1:22 PM

@yuggib I left the year before we read that

ACuriousMind

The when comes from the fact that I chose to interpret the participle construction britannos...scribentes temporally

Writing the et between britannos and latinos is a mean red herring because one might think it just means "British and Latin words"

0celo7

-2

Q: Singularity in the context of the Quantum mechanics

In the TV program , Professor Michio Kaku had told that singularity can be defined as the rotation of the neutron . I'm searching whether the insist was right or wrong . How does the quantum mechanics or string theory define the singularity ?

quantum-mechanics quantum-field-theory singularities neutrons

F*cking Kaku.

I have a new policy of censoring

Rigor

Good policy

0celo7

@ACuriousMind yes, that's how I translated it

ACuriousMind

@0celo7 But then the scribentes is left hanging, so you know it's wrong ;)

0celo7

1:25 PM

@ACuriousMind exactly

5 mins ago, by 0celo7

I'm bad at Latin

:D

yuggib

@Rigor cultura.va/content/cultura/it/collegamenti/accademie-pontificie/… (on the top there is the english version as well ;-) )

0celo7

.va?

forgive my ignorance, what is that

yuggib

vatican's city :-D

0celo7

huh, cool

Rigor

@yuggib thanks for sharing

yuggib

1:27 PM

I cannot imagine a more standard reference for the latin language

despite the religious bias...

@ACuriousMind I agree that's a mean red herring...even if not on purpose ;-P

ACuriousMind

The ancient Romans didn't do that on purpose, either, and yet they managed to produce a lot of those :D

0celo7

42 close votes D:

ACuriousMind

Yeah, the counter has been unusually high for a few days now

Probably @Jim is slacking off again :P

0celo7

working on it

:(

wow I only have 500 close votes

ACuriousMind

You and Neuneck just dropped the pending flags from 58 to 41, not bad

Kyle Kanos

1:45 PM

How can a car, which is a man-made object, move faster than a man? — babou yesterday

ACuriousMind

Sometimes SE is so deep.

Rigor

:-/

0celo7

@KyleKanos I thought that was a legitimate question at first

ACuriousMind

2:01 PM

@0celo7 The compiler question or the car question?

0celo7

@ACuriousMind car

I don't know anything about compilers

Jim

2:38 PM

@ACuriousMind usually a good bet

yuggib

@Jim Your code is always compiling

Jim

@yuggib I have a better excuse. I don't have a job

^ 100% good reason to be slacking off

yuggib

no one can object on that...

Stan Shunpike

4:23 PM

@ACuriousMind So, are gauge fields related to why we call photons and gluona "gauge" bosons?

0celo7

@StanShunpike Yes.

The SM itself is a "gauge theory".

Jim

I gauge this to be an appropriate line of questioning

Stan Shunpike

Hahaha

@0celo7 so are bosons gauge fields?

0celo7

Serious question time: should I tell any professors I want to work with about my SE account?

@StanShunpike NO

We have gauge bosons $\subset$ bosons

Huy

@0celo7: Why do you want to tell a professor?

0celo7

4:30 PM

@Huy It helps me stand out from the crowd.

Huy

I don't know if they'll sacrifice time to look at some student's online profile on a physics "forum".

0celo7

probably not

Jim

You could tell them, but be careful about it

0celo7

but on off chance

I won't bring it up, but I could put it under "interests" or something on my resume, no?

Jim

I didn't tell my supervisor because I couldn't see how saying "Hey, so this is what I was actually doing instead of working on my project" would be at all a good thing

Huy

4:33 PM

^ +1

0celo7

I would put it along the lines of: "I'm curious about how things work and also I can do more math than the average freshman"

Jim

Yeah, in your case, it's more impressive than detrimental. But just remember that in the future, they'll know about it and will be able to catch you spending time on here when you should be working

0celo7

I should be working right now :P

Reading about ODEs...

kinda boring

Huy

What course are you doing ODEs in?

0celo7

OK something died in the dorm

this is bullshit

someone took a shat somewhere

this is not a normal smell

Huy

4:36 PM

Sounds delicious.

0celo7

what course? you mean book?

Huy

No, course. :D

0celo7

idk what you mean then

am I missing something

@Huy OH

Literally "ODE (honors)"

FenderLesPaul

hi

0celo7

stop distracting me

FenderLesPaul

4:49 PM

no

0celo7

why

college advice needed: what do if my roommate has been in the bathroom for 50 minutes and I need to go

Huy

renting an own flat solved such issues for me

0celo7

no monies

also why the hell has he been in there for so long...

Huy

I see a relation between your question and your statement earlier that someone took a shit somewhere

0celo7

no that was in the hallway

Huy

4:54 PM

maybe that's the answer to your question then

Jim

@0celo7 1) Hold it in and do a dance. 2) find a bathroom elsewhere. 3) wet yourself and when he comes out scream "See! That's what happens! This is all on you!"

0celo7

@Jim 1) is what I'm doing 2) meh 3) interesting...

@Huy I like the clacking noise

Huy

me too

don't you have public bathrooms at uni or so?

brb gotta get me some dinner

0celo7

We do but far away for nice ones

I'd have to walk all the way over to the hill

Jim

I forgot, 4) pick the lock and barge in saying it's a bathroom emergency. 5) Designate an emergency toilet for use in emergency situations only and then pick an object to pee in

0celo7

4:57 PM

not pee

Jim

6) cork

0celo7

haha

user54412

5:11 PM

private bathrooms for freshmen? oh how we spoil our youth

0celo7

technically I'm a sophomore thank you very much

Jim

sounds like he has an apartment style dorm

0celo7

we're the only dorm that gets them

"honors living and learning community"

user54412

you're missing out on all the progressive awkwardness I had of having co-ed bathrooms and showers

0celo7

ok that's not a thing here

Jim

5:14 PM

I had those too, there was never anything awkward

0celo7

we're the only building that even has men and women on the same floor

ok this is getting strange

what if he had a heart attack

user54412

21

Q: What's the best way to dispose of a body in the backcountry?

Suppose you needed to dispose of a large carcass for one reason or another while in the backcountry... what would be the best way to dispose of it in the woods so that it wouldn't be discovered? You always hear stories of people burying bears that they've had to shoot, but I can't imagine digging...

leave-no-trace garbage-disposal

Jim

I don't think he's in the backcountry

0celo7

It's not like I killed him

Jim

@0celo7 Can't you shout and ask him what's taking so long?

0celo7

5:20 PM

@Jim considering

Jim

@0celo7 That's not the way I'm going to tell it to the police

0celo7

You're Canadian, i.e. no credibility

Jim

we're polite and nice and honest. Our reputation makes us very credible

user54412

I've done some serious thinking on a toilet. He might just be solving a really hard problem.

Jim

or playing a game on his phone

after an hour, you really should have already asked

user54412

5:24 PM

tell him there's an internet chat room eager to hear his status

Jim

0

Q: Friction between two bodies placed one above another

I'm recently facing a bit confusion regarding the friction between two bodies. Suppose there's two bodies, one placed on another. There is frictional force $ f $ between the base body and floor and frictional force $ f' $ between the two bodies. Let the upper body is pulled with a force $ P $ gre...

newtonian-mechanics forces friction free-body-diagram

^ I believe that's called sex

FenderLesPaul

if someone is in a bathroom for 50 minutes

and not showering

I wouldn't want to go inside for a day

0celo7

@0celo7 T does depend on the metric. It's related by the Field Equations. T is equal to G divided by k. I would suggest thinking through your comments a little more. — Horus 3 hours ago

D':

Jim

he's right. When I want to figure out T, I usually do so with an equation that is 60-80% metric terms

0celo7

cf. my response

FenderLesPaul

5:29 PM

While his statement is correct his reasoning is just flawed

0celo7

cf. my second comment

I think that is a good analogy

FenderLesPaul