The h Bar

Trivial, even

user84215

Yes.

1:43 PM

Does anyone know reading a screw gauge?

Total scale reading= Main Scale reading+ Circular scale reading.

( no zero error)

So 2 + 0.56 = 2.56. Anything wrong?

Looks ok to me.

@skullpatrol Thank you so much sir.

Thanks for asking :-)

Do you have a couple more minutes to check a Vernier scale too?

I can try.

1:51 PM

I did like 3.4 + 4*0.01

Main Scale reading+ VSR * Least count, the last being mentioned

@PrathyushPoduval @WrichikBasu You people too kindly give a look to above,

Vernier scale

A vernier scale is a visual aid that allows the user to measure more precisely than could be done unaided when reading a uniformly divided straight or circular measurement scale. It is a scale that indicates where the measurement lies in between two of the graduations on the main scale. Verniers are common on sextants used in navigation, scientific instruments used to conduct experiments, machinists' (or jewelers') measuring tools (all sorts, but especially calipers and micrometers) used to work materials to fine tolerances, on theodolites used in surveying, and in absolute encoders to measure...

23 hours ago, by John Rennie

@SirCumference How on Earth would I know? I struggle to understand how many of the people I meet from day to day manage to tie their own shoelaces.

Why on Earth were the stars removed on this

A mod decision, no doubt.

Perhaps, they felt "shoe laces" were being discriminated against :P

@skullpatrol Now let's play the waiting game for this to be unstarred

:-D

Anonymous

2:02 PM

@skullpatrol Maybe JR himself unstarred it...;p

Anonymous

I don't think mods would do that

Perhaps.

Anonymous

@JohnRennie It's getting downloaded....seems like a huge download...78% now

Well, on a happier note, what have y'all been up to?

Anonymous

2:05 PM

@Blue Sounds fun

Anonymous

Yeah! This slow laptop drives me crazy sometimes

Anonymous

Too much junk

Q: Time in a black hole does it stop?

I don't think windows 10 is going to help the problem

Anonymous

2 hours ago, by John Rennie

When you do the W10 install I would completely wipe the disk. Don't try to upgrade th W7 install or it will inherit all the stuff that'scurrently making W7 slow.

Sid

@the denizens of the hbar, would the following question be a good fit in Physics.SE?

-2

Does time stop in a black hole since photons orbit sphericaly around it and not within .?do photons get absorbed in a black hole or do they just circle outside it's no enter zone?

Anonymous

2:08 PM

@Sid Pretty sure that has been asked several times over here

Anonymous

Just search in the main site

Anyone remember obe?

Anonymous

Sure...why?

Anonymous

@SirCumference

@BalarkaSen Any Bowie songs you'd recommend?

@Blue Good times...

Anonymous

2:11 PM

@SirCumference Yeah...he left due to some personal reason iirc :/

@Blue Remember Mafia too?

And Obliv?

And Bernardo...

@SirCumference Haha, hard question. Do you like 60s/70s Bowie more or 90s Bowie more? There's also the Berlin era which is mostly experimental.

I could suggest something randomly if you want

@BalarkaSen I'm a bigger fan of 60s/70s

You listened to anything from Diamond Dogs?

@BalarkaSen Huh, not yet

2:15 PM

Ok, here's two suggestions: "Rock n roll suicide", and "Sweet Things". The first is from Ziggy, second is from DD

Well, I've heard Rebel Rebel

@BalarkaSen K, thanks :)

@BalarkaSen going to a Navier-Stokes seminar tomorrow

There should be a drinking game for when "there exists a constant C" is said

no idea about that stuff

lol

What about the 80s?

70s-80s is the Berlin era

Anonymous

2:20 PM

@SirCumference Yes, all of them. :)

Anonymous

Bernado hasn't really left

@Blue I dunno. Some of them aren't really as catchy/moving as some of his biggest ones like Starman and Space Oddity

Anonymous

He's been busy after shifting to SB

@SirCumference Wow, I thought you were talking about Bowie recommendations

Anonymous

@Blue self-ping

Anonymous

2:22 PM

wow...it works :D

I find a lot of his 90s and post-90s work moving but in a different way. (Think about "Sunday")

@skullpatrol And we arrive at 23 minutes!

We new that was coming pal.

@Sid No, because it is a) not really clear what it is asking and b) stuff (matter and photons) falling into black holes has been discussed here at several questions already.

Let's face it, we're not wanted around here @SirCumference

At least by "the powers that be."

2:29 PM

@skullpatrol Please don't make such blatantly wrong allegations.

If the "powers that be" actively didn't want you here, you would not be talking here right now.

So stop it with the overblown dramatization

@ACuriousMind From our perspective it seems like posts are randomly unstarred for no reason

Not ours in particular, but other people's

Sid

@ACuriousMind then, it's good that Puzzling mods know more than me about Physics.SE :P

@SirCumference So? That's "this particular post is maybe not a good fit for the starboard" not "you're not welcome here".

@ACuriousMind That was skull's claim. I've been complaining about this

See @Blue john is not here.

2:35 PM

I mean, the star buttons might as well be reserved for mods. They decide what's a "good fit" anyway.

@BalarkaSen today I'm going to "group actions on large scale spaces"

They decide who is a "good fit" for their room.

@SirCumference I think the ratio of unstarred posts to all posts is small enough that that's not an accurate representation of the situation. Sometimes people say things which are not outright delete-worthy but also not good to have on the starboard (I'm not the one who unstarred JR's post but I imagine that's because it might look unwelcoming to new users if there's a prominent message about most people being stupid in it). How you get from that to "only mods effectively star things" is beyond me.

@ACuriousMind That's not what I'm saying. My point is that the mods effectively decide what belongs on the starboard, not us. Why even let us star when it'll be removed a few minutes later due to some arbitrary criteria that no one seems to get?

@SirCumference Why even let people vote on posts if mods can unilaterally delete any post?

2:42 PM

@ACuriousMind Because mods don't generally remove posts people like. The starboard is literally all the posts that have been liked.

Let it go @SirCumference you're gonna end up banned.

@SirCumference Well, we generally don't remove starred posts either.

@skullpatrol I think the mods here are more civil than that...

don't test them

@skullpatrol I resent the implication that he might get banned for politely expressing his opinion. Please take your agitation elsewhere.

2:43 PM

@ACuriousMind There's a difference between removing posts with 15 downvotes and removing stars on liked messages

resent?

Bye

Is it not up to people to express their opinions on posts?

@SirCumference Sure it is! That's mainly what the reply function is for! I know that most rooms use the starring feature like a "like" button (and there's mostly nothing wrong with that), but actually that's not even what it was intended for, cf the faq entry on stars

(what's the starboard?)

@CooperCape That thing you're on now

2:45 PM

@CooperCape The list of the messages with stars to the right of the screen (unless you're on mobile)

ahh that thing

@ACuriousMind And if 3 people find it interesting, why should mods determine whether it's a good fit for the starboard?

@SirCumference For instance, as I said, the starred message may be funny, but it may also look unwelcoming to users who didn't get the context. In that case, it's conducive to a welcoming atmosphere to remove it. Moderators/ROs are the ones whose task it is to make these decisions. If you disagree that such moderation should happen, you're of course free to, but that's how SE chat works.

@ACuriousMind Are the opinions of the majority of non-mods really that irrelevant?

Back

What part of "starboard" didn't you understand @CooperCape

2:53 PM

what it was...

and then why there seems to be a discussion stemming from it...

star + board

@SirCumference Yes and no. If there is a general feeling that too many messages get unstarred and that's a bad thing, then we would take that under consideration. But you won't change the fact that such unstarring might happen, only its frequency.

Anonymous

@skullpatrol What?

I mean I just trust that mods are doing their mod stuffs well soo...

@ACuriousMind Many of us have been trying to lower it's frequency. I don't know how many more people need to complain before it becomes noticeable.

2:55 PM

You thought john removed the stars @Blue but he's not here

Anonymous

@skullpatrol He is currently not here. But he might have removed them when he was present. Are you sure the message was unstarred when he was not present? Anyway...this is too trivial an issue

Agreed @Blue

Let's drop it @SirCumference

"trivial"

@SirCumference Sorry, but "many of us" is plainly not the impression I've gotten. Complaints about this are rather infrequent (I can't recall you ever bringing this up before), and we also get the occasional request to unstar something.

Searching for variants of "starred", "stars", "remove stars" and "unstar" in the transcript affirms my opinion that there hasn't been overwhelming dissatisfaction about how the star board is curated, and on balance about as many "why did you unstar that?" as "please unstar that" type of comments.

how goes the preparation for your thesis defence? @ACuriousMind

@ACuriousMind What seems to be the issue here?

@BalarkaSen We will begin the talk by giving a brief refresher on the basics of large scale geometry. Let G be a group that acts on X and let $(X,\mathcal{X})$ be a large scale space. Then we will show a construction of a new large scale structure, $\mathcal{X}_G$ that is $\mathcal{X}$ with the addition of uniformly bounded sets so that each function $h_g$ that sends $x$ to $g\cdot x$ is

close to the identity map. We will end the talk with the proof of the following theorem: Let X be a discrete bounded geometry metric space and let $\mathcal{X}$ be the large scale structure induced by the metric on X. Let G be an amenable group that acts on X by coarse equivalences. If $(X,\mathcal{X})$ has property A, then $(X,\mathcal{X}_G)$ has property A.

3:06 PM

@0ßelö7 If you really want to know, just read the transcript. How's the poster coming along?

@ACuriousMind I sent it to the printer

waiting to hear back from them

How many equations vs how many pictures does it have? ;)

@ACuriousMind I can email it to you

it has three pictures

Also, I read something about exploding stars, I hope that's on there

@ACuriousMind it is!

3:07 PM

People looove exploding stars

I discovered something really neat

it's not a dynamical explosion, sadly

Anonymous

What poster?

Anonymous

Some presentation ?

and I'm not really sure how to interpret the answers. Need to do a lot more work

@0ßelö7 What's a large scale space?

3:10 PM

@0ßelö7 How is it an explosion if it isn't dynamical?

I'm guessing this has to do with coarse geometry

@BalarkaSen no clue

@BalarkaSen yeah

@ACuriousMind read the poster!

email it to me too

@0ßelö7 nice bait

@BalarkaSen bait?

3:13 PM

Trout or salmon?

add "shoe laces" to that list

@0ßelö7 Fine, send it :)

@ACuriousMind dunno how

@0ßelö7 If $f(z) dz \otimes d\bar{z}$ is a conformal metric on my Riemann surface is there an easy way to see the Gaussian curvature is $K = \Delta \log f$ (modulo factors I forget)?

or do I have to do the coordinate computation now

@BalarkaSen There are formulas for the curvature of conformal metrics

Now would be a good time for you to prove them

formulas relating the curvatures of $g$ and $e^fg$

I'll try it out

maybe not now though

3:18 PM

@SirCumference I removed the stars because having slept on it I thought it was rather bitchy and not a comment to be proud of.

@BalarkaSen The usual reference is an appendix in Wald, "General Relativity"

(same formulas for any signature)

Thanks

@JohnRennie All right, I apologize to @ACuriousMind, but I legitimately find myself wondering "why did my post lose its stars" from time to time

@SirCumference what happened?

@CooperCape There's a starboard waiting in the sky...

3:20 PM

loool

@ACuriousMind Steam doesn't work on my laptop anymore so if you sent it to me there I won't see it until tonight

@SirCumference if stars are removed then accuse me first as I'm the most aggressive destarrer. If I would feel embarrassed for a visitor to this room to read something on the star board I will usually destar it.

What about my "shoe lace" comment? @JohnRennie

@0ßelö7 My email is: (initial of my first name) + . + (my last name) + @gmx.de (spell umlauts as ae,oe,ue)

That was obviously sarcastic humour @JohnRennie and not offensive.

3:24 PM

(it's not a secret but I would prefer the string not to be searchable)

@skullpatrol I removed the stars on your and Sir's message because I thought that whoever unstarred JR's comment did that to avoid drawing more attention to it, which was what these two comments were also doing.

So delete it.

Shufflepants

any chance I could get more eyes on https://physics.stackexchange.com/questions/354419/is-the-expansion-of-the-universe-really-evidence-against-the-universe-being-insi
to confirm it's not a duplicate?

@ACuriousMind Jewliger doesn't have umlauts tho

Move it to the trash.

@skullpatrol I don't unstar posts just because I'm bored. As I said, I do it when I feel the post would be offputting to new members. Even then I do it rarely - on average less than once a day.

3:28 PM

can someone please tell me what was unstarred??

In that case I was unstaring my own post so I didn't think it would be controversial.

Ok. Case closed.

@0ßelö7 ¯_(ツ)_/¯

we will never be rid of these stars

yesterday, by John Rennie

@SirCumference How on Earth would I know? I struggle to understand how many of the people I meet from day to day manage to tie their own shoelaces.

3:30 PM

I liked that comment

you would

quick someone star it...

@skullpatrol do you want to fight?

@BalarkaSen It was funny at the time, but it is bitchy

Come at me @0ßelö7

3:31 PM

@skullpatrol I will defend the maiden Balarka's honor

IN AN OPEN FIELD

@JohnRennie Depending on how you interpret it! I genuinely struggle to tie my own shoelaces, so I am surprised to see so many people being able to do it around me

@BalarkaSen this

Her highness?

I am so smart and and constantly thinking about partial differential equations that I can't be bothered to think about tying them

2

I tie my shoelaces about once a month :P

3:32 PM

@ACuriousMind oh jesus

hipster alert

Thongs?

I don't think I've untied mine since I bought them...

@0ßelö7 "I'm so smart and and" :P

@0ßelö7 I'm not leaving them untied the rest of the time, I'm just wearing shoes I can get into/out of without untying the laces

3:33 PM

jk, I wear sandals

@SirCumference what?

I don't need them shoelaces

@0ßelö7 "and and"

@SirCumference so?

it's clearly not a serious comment

I know, that's why I starred it

3:34 PM

@BalarkaSen Oh, during the Mayweather-McGregor event there was a fight where one of the boxers was apparently not stupid and took a class on elliptic PDE in college

he lost, badly

@CooperCape Want to see a magic trick?

Leave the starring to the experts :P

@ACuriousMind that's pretty sad

When doing rock paper scissors, ask the other person the color of their shirt first. Then they will always pick scissors

Anonymous

@BalarkaSen You are allowed to wear sandals to school? If it were my school we'd be kicked out :P...college is a different story though....we can even go bare feet

3:36 PM

this is just illegitimate facts.

@0ßelö7 lol

@CooperCape It's truth, try it

I won't have any human contact until Friday morning... (fortunately)

Anonymous

Let's play online rock paper scissors @CooperCape :D

@Blue yeah i walk my school rocking those sandals

3:38 PM

yoo bluey what colour;'your shirt?

(I care this is not tactics...)

"I'm blue da ba dee da ba dae"

Anonymous

@CooperCape blue..of course :'D...

do you wear sandals with long pants

-_-

okay okay

I choose rock...

3:39 PM

@ACuriousMind no idea if that will get to you

@0ßelö7 yes

$$>!choose scissors$$

@BalarkaSen oh wait, you think Gromov is a handsome man

@0ßelö7 got it :)

Anonymous

I have a gigantic collection of blue t-shirts

Anonymous

3:39 PM

Lol

Anonymous

@CooperCape I choose pApeR

Why can't you post a picture of your poster here? @0ßelö7

SodiumBromate Bluey... you chose scissors.

@skullpatrol it has my phone number

user228700

Hi, everyone :-)

3:41 PM

Hi

well... sodium hydrogen bromate

Hi :)

user228700

What's up?

öperweiner

imgur.com/15drKGc

Nothing much, you?

user228700

3:42 PM

@SirCumference Holed up in my hostel rooom, as per usual :-P

öperweiner

it's correct right?

Mr. Xcoder

I smell... mechanics!

@0ßelö7 He looks quite cool

@Kaumudi.H Your roommate any better?

user228700

@SirCumference I think so. She switches off the light at 11 PM, which is definitely an improvement! :-)

user228700

3:43 PM

How's college?

@Kaumudi.H Pretty good, classes start tomorrow

@BalarkaSen he doesn't look human

user228700

@SirCumference Ooh, nice! :-) Are you excited?

@Kaumudi.H Kinda. I'm taking Spanish but I dunno how well that'll go

@0ßelö7 evidently you don't have much background in slavic beauty

user228700

3:45 PM

@SirCumference Oh, wow, why?

Can't you cover your phone number? @0ßelö7

@skullpatrol No

@Kaumudi.H I'm not a native speaker

user228700

Right, no, I meant to ask why you're taking Spanish.

why not

3:46 PM

@Kaumudi.H Mexico

user228700

@BalarkaSen Oh, hi, there! :-)

spanish language literature is really rich

ohi

@ACuriousMind Soooooocles are confusing.

Can you read Spanish @BalarkaSen?

user228700

@BalarkaSen Wadup?

3:47 PM

nah

@Kaumudi.H Well I enjoy learning it and am decent at speaking

Who knows how it'll go

user228700

@SirCumference Nice! :-) Good luck! I hope it goes as well as you hope it will (:-P)

@Kaumudi mixing math with memes

@ACuriousMind So something I proved, is it true? Let $A$ be a unital ring, and consider module $U,V$, and $f\in\mathrm{Hom}_A(U,V)$. If $S\subset U$ is simple (semisimple), then so is $\phi(S)$?

user228700

@BalarkaSen (Y)

3:49 PM

@0ßelö7 I have no idea what a "soooooocle" is

@ACuriousMind It's me saying socle dramatically

I don't know what that is either

El'endia Starman

My question in the Math.SE main chat room quickly got buried. Maybe you guys can help me figure this out? (It's a math question in a physics context.)

in Mathematics, 14 mins ago, by El'endia Starman

Hey guys, I'm trying to work through and understand this: http://www.aoengr.com/Dynamics/LagrangianMechanicsPendulum.pdf . The part that's tripping me up is the first half of the third page, where apparently $\frac{\partial{L}}{\partial{\theta}} \left( \frac{1}{2} m l^2 \dot{\theta}^2 \right) = 0$ and $\frac{\partial{L}}{\partial{\dot{\theta}}} \left( m \cdot g \cdot l \cdot (1 - \cos{\theta}) \right) = 0$. I don't understand why you can do that.

Like a support for a plinth thing @ACuriousMind

@ACuriousMind Oh no

@ACuriousMind I literally took this course because you said you knew all of the stuff in the introduction

3:50 PM

@0ßelö7 It is very possible that I know what it is but not the English name

@ACuriousMind Söcle

(lol)

El'endia Starman

To be clear, I understand that when you're working with partial derivatives, you can treat variables other than the one you're deriving with respect to as constants. What's tripping me up is that $\theta$ and $\dot{\theta}$ count as different variables in partial derivatives?

@ACuriousMind $\sum\{S\subset U:S\text { is semisimple}\}$

@Kaumudi.H so what's going on in your end of the world

hanging in college

user228700

3:53 PM

See:

user228700

11 mins ago, by Kaumudi. H

@SirCumference Holed up in my hostel rooom, as per usual :-P

user228700

The rest of our college had Onam celebrations today but first years were entirely exempted from the event. Hence, we got a holiday.

It's past 18:45 anyway isn't it? They chain you up at 18:45 :-)

iseewhatyoumean.winrar

user228700

@JohnRennie Sigh. Way past 18:45, I'm afraid; It's 21:25 over here.