The h Bar

Sir Cumference

12:02 AM

Howdy

Secret

12:18 AM

Bots have a culture, and we need to devote time to understand it

David Z

12:28 AM

@Hippalectryon Well, what I really said (or meant) was that I'd be interested in a bot, but probably not a fork of Chembot. Some other people in the room seemed more interested in that though.

Hippalectryon

@DavidZ What about I let the bot here for a test period with those arxiv commands and commutative graph commands for instance, and see how it goes ?

David Z

@Hippalectryon I'm okay with that. Not that it's really my decision, though I'm not entirely sure how the decision of whether to enable to bot should be made. A fairly safe route is to make a meta post asking whether to do it. Or you could just start the bot up and see how it goes.

Hippalectryon

@DavidZ In the chem room we went with the option of simply asking the room mods, since they had control over the room's guidelines

Also, I can add the room's mods as bot mods just as I did with the chem room mods (basically you can make the bot stop working for any period of time)

David Z

@Hippalectryon I guess that makes sense to do, if you do enable it... but I don't think us being bot mods or not is a major factor in whether most people will be okay with it. (Of course somebody needs to have control over the bot, but it matters little to me who it is.)

Hippalectryon

I mean, the only real problem I can see with the bot is that it might be used to "spam" the chatroom since I'll have removed the "funny" commands. But of course, it's up to the users to say whether they want to keep it or not

0celo7

12:39 AM

@ACuriousMind The $\hbar$

Sir Cumference

@0celo7 Then the joke is lost to most people

0celo7

@SirCumference We only want people who get the joke, clearly.

David Z

@Hippalectryon If you were to take that approach here, it would be up to the room owners, i.e. myself @ACuriousMind @rob @Qmechanic @dmckee and Manishearth. Like I said, I don't mind trying it out for, say, a couple weeks. But we can see what the others say. I do think this is not the sort of thing that really needs to be decided by the room owners; it makes sense to leave it to the community.

0celo7

And "the h bar" is not any better, really

anyone who knows what h bar is will know what $\hbar$ is

Sir Cumference

@0celo7 I think they would know what $\hbar$ is if they understand "The h Bar"

Saying it out makes it more obvious that this is a "bar"

0celo7

12:43 AM

That's your problem

puns should not be obvious

Sir Cumference

Au contraire, the best puns are the worst puns :)

Take my name for example

Hippalectryon

@DavidZ Ok what about this : I develop the bot's fork for the h bar, asking which commands the users would like and implementing them in chemobot's chatroom but not here. That way people can see how the commands work and test them, but it won't have any impact here. Then, according to how this goes, you guys decide whether it should be tested in this room.

0celo7

@SirCumference Your name reminds me of...I shan't say what it is out of fear of execution.

Sir Cumference

@0celo7 Well, now my mind's free to interpret what you were going to say...

David Z

@Hippalectryon Again, that sounds good to me. I mean, I'm not going to come right out and tell you "yes, do that"; it's up to the community. But all these are valid options.

Hippalectryon

12:46 AM

Well at least testing it in chemobot's chatroom won't annoy anyone :D

0celo7

@DavidZ Am I allowed to make rhymes of sexual innuendos?

@SirCumference Meh. It's medical. Circumcision.

David Z

@0celo7 Nobody can kill you through the internet, so stop talking about execution. Also, if saying something would get you suspended, there's a good chance alluding to the thing would also get you suspended. So if you think you shouldn't say a thing, don't allude to the thing either.

@0celo7 No

DanielSank

> Nobody can kill you through the internet

You sir, have not seen Ghost in the Shell.

David Z

And every day it gets harder to fight the urge to su to the user and freak people out.

DanielSank

...but you should, especially the series, because it's excellent.

David Z

12:49 AM

Not what you meant, I know, but it seemed appropriate :-P

@DanielSank I can tack it on to my list

0celo7

@SirCumference Well?

Do you agree or not?

DanielSank

So eh, how come so many users get capitalization wrong?

They say stuff in "In the theory of Quantum Mechanics,...".

Who's teaching people to do that?

0celo7

Lots of people capitalize fields

@DanielSank common knowledge

DanielSank

@0celo7 wat?

Field names are treated as proper nouns now?

David Z

@DanielSank I asked someone about that once, on reddit I think, and they said they thought physics was a proper noun. I'm not sure where they got that idea (and neither were they).

Hippalectryon

12:52 AM

DanielSank

@DavidZ Woah.

@Hippalectryon hahah, nice.

0celo7

I don't know what a proper noun is

Is it just one you capitalize?

DanielSank

A thing that you capitalize.

0celo7

@DanielSank Is that the definition or a theorem?

David Z

7

Q: Should names of scientific theories be capitalized?

I'd really like to safely write stuff like Special Relativity, Quantum Mechanics, Theory of Evolution without capitals; but I don't want to regret it, whence my question. Should the name of scientific theories be written with capitals?

somewhat relevant

DanielSank

12:54 AM

@0celo7 A proper noun is roughly a name of a person or place.

David Z

@0celo7 A property of proper nouns is that they should be capitalized, but that is not their definition. (At least, I've never heard of anyone defining them like that.)

DanielSank

It is the case that they are capitalized in English.

David Z

As with all other things in English, the rules are weird and at some point you will wind up having to memorize a list of exceptions (or perhaps more precisely, no reasonable set of rules can completely distinguish between common and proper nouns without individually classifying at least a few of them). Anyway, one of the rules goes something like this: academic fields are not proper nouns (e.g. physics, history) unless they are also the names of languages (e.g. English, Swahili).

0celo7

@ACuriousMind Oh my god

DanielSank

^ So how come so many people capitalize?

English (at least in the US) is supposed to be descriptive, not prescriptive. We actually don't have an official language correctness authority.

David Z

1:01 AM

@DanielSank I assume because they don't know that rule? To be fair, I didn't actually know it either until I looked it up precisely because of this issue, I'd just known from experience that you don't capitalize "physics".

0celo7

@ACuriousMind If $U-\{x\}$ were not simply connected, this would contradict $\Bbb R^2-\{x\}$ being not simply connected. Take a loop around $x$. If this were nullhomotopic in $U-\{x\}$, it would also be in $\Bbb R^2-\{x\}$. But we know that's not true.

@BernardoMeurer FUTURE DROPPING A SECOND ALBUM TOMORROW

DanielSank

Black Holes collapsing

It's not just field names.

I see "Electric Field" all over the place too.

Where is this coming from?

rob

@DanielSank Orthography is hard, and people who ask questions here are concentrating on something else.

I used to be a snob about that sort of thing but decided to quit.

DanielSank

Working for clarity and being a snob are not the same thing, sir.

I simply edit and move on.

Some times, if it's a new user or one with an obviously foreign name, I'll leave a comment.

rob

4

A: How to ignore a presenter's bad english?

So I'm a native English speaker, and I used to be kind of a snob about people whose spoken English was poor. I got over it. I remember the exact instant that I got over it, in fact. Here it is: I was an undergraduate, and I visited a seminar on a subject that interested me but that I didn't know...

DanielSank

1:13 AM

Orthography may be hard but it's also rather important.

rob

Not trying to imply you're a snob, but that I used to be one, and i'm more relaxed now.

0celo7

lol

DanielSank

@rob Well fortunately around here we can literally rewrite the author's words. This not only improves readability for others, but it actually helps the author learn to use better English!

rob

@DanielSank Truth

0celo7

@rob Wait, you got your PhD here?

I thought just UG

DanielSank

1:17 AM

@rob I look at one of the main functions of this site as an engine for making the physics community better at communication.

rob

@0celo7 Both degrees from the same school. There was a pretty girl involved --- staying at the same institution was a solution to the "two-body problem".

4

I should use the present tense there, because that pretty girl and I have been married now for fifteen years.

anonymous

@rob Pretty sweet story :D

0celo7

I'm tearing up.

rob

@0celo7 ... the dance floor.

0celo7

@DanielSank Have you heard of Hadamard matrices?

rob

1:44 AM

Hadamard matrix

In mathematics, a Hadamard matrix, named after the French mathematician Jacques Hadamard, is a square matrix whose entries are either +1 or −1 and whose rows are mutually orthogonal. In geometric terms, this means that each pair of rows in a Hadamard matrix represents two perpendicular vectors, while in combinatorial terms, it means that each pair of rows has matching entries in exactly half of their columns and mismatched entries in the remaining columns. It is a consequence of this definition that the corresponding properties hold for columns as well as rows. The n-dimensional parallelotope spanned...

0celo7

@rob I know what they are, I attended a talk on them.

The speaker mentioned Quantum Information Theory.

rob

@0celo7 What did you learn?

0celo7

Nothing, really. The talk was preparatory. Part two tomorrow.

The hadamard matrices lie along varieties is what I learned, I guess.

And that physicists are desperately looking for them in six dimensions.

rob

@0celo7 Sounds like a challenge in a four-dimensional spacetime :-)

0celo7

@rob yes. The analytsts in the audience had a good laugh at physicists too

The speaker said that the physicists were writing a bunch of equations that probably do not have solutions

He said the physicists use their "usual rudimentary methods"

rob

1:57 AM

I always think it's strange to refer to scientists as if we were a monolithic group. ("Physicists are desperately searching" vs. "There are physicists who are desperately searching.") No one's come into my office looking for Hadamard matrices.

... though looking in my office would be an unusually rudimentary method.

DanielSank

@0celo7 yes

@rob not that you know of...

0celo7

@DanielSank so these are actually useful things?

DanielSank

@0celo7 sure

0celo7

@DanielSank what for? The speaker was pretty cryptic

DanielSank

@0celo7 they show up in quantum algorithms.

0celo7

2:15 AM

@DanielSank are you being intentionally...this?

DanielSank

2:25 AM

@0celo7 eh?

Sir Cumference

@0celo7 That's what I was thinking

That or "Sir Cum", as some people online call me...

skill patrol

2:44 AM

T.M.I.

Sir Cumference

@D17 What's with your new name?

@skillpatrol That's true...rather that not be my nickname here

skill patrol

You could change your username to 2pi*r

Sir Cumference

@skillpatrol That's also my nickname :)

skill patrol

:)

Sir Cumference

3:00 AM

fduck

Admittedly, that was a mistake

0celo7

@SirCumference ...

@SirCumference disgusting

Sir Cumference

@0celo7 Huh?

0celo7

Language.

There are children here for pete's sake

Sir Cumference

I realize that was moronic...

skill patrol

(removed)

Sir Cumference

3:07 AM

Sigh...

anonymous

@SirCumference Which site is that?

skill patrol

What happened to your avatar? @dmckee

Sir Cumference

@anonymous Astro

@skillpatrol His avatar is the same

anonymous

Maybe that was real Shrek typing it :P

dmckee

Did something happen to my avatar. I still see the high-contrast, monocrome head-n-shoulders shot.

Sir Cumference

3:09 AM

@dmckee Nothing happened that I see

anonymous

@dmckee No.

Sir Cumference

@0celo7 Woah, I feel old

anonymous

Does the name of moderators appear written in blue ?

Wow. I never noticed it before !

dmckee

da-dum-da-dump

da-dum-da-dumb

D17

@SirCumference different shade of blue

dmckee

3:18 AM

I got the blues, baby!

D17

obe doesn't really mean anything it's just a shade of blue that I liked but i want to switch it up a bit, new name doesn't mean anything either xD

0celo7

@dmckee oh god

what happened to you?

@D17 Hello, welcome to the h Bar!

If you're here for JEE, please say so now!

D17

thx

no I'm not.

0celo7

@dmckee :

Sir Cumference

@D17 Speaking of which

Since you lost the astro design, I remade it

We still working on it?

@0celo7 Here's something hilarious you might've missed when you changed your avatar to that...zombie thing

D17

3:29 AM

@SirCumference yes

Sir Cumference

@D17 Cool

So I shared the design with other people, they all agreed it needed more than just blue

D17

waaa

Sir Cumference

Also, by "remade", I mean I drew over the PNG file of the background you sent me and made it into a vector

@D17 As a matter of fact...there's not much blue in space

I mean, blue stars are exceedingly rare

D17

ok

Sir Cumference

@D17 Also, here's your vector logo

gist: 0c56554efd73dab75025e2019b330c57, 2017-01-06 22:18:06Z

AstroLogo.svg

D17

3:33 AM

nice

Sir Cumference

So, let's think

The logo doesn't look too good as a favicon...

Even though I love it as a logo

D3075

tbh

i don't even like that logo

Sir Cumference

Huh...

D3075

the favicon should be a generic star

i think

Sir Cumference

So we're changing the logo?

D3075

3:35 AM

yes

Sir Cumference

@D3075 Like a five pointed one?

D3075

yes

does the favicon have to be the same as the one on in the banner

Sir Cumference

Hmm...will it really seem different from every other site/logo with a star?

@D3075 It'd certainly make sense. Every SE site does that.

After all, the favicon/banner icon symbolizes the site

Makes it unique

anonymous

@SirCumference A galaxy type symbol would suit it better perhaps

Sir Cumference

@anonymous That's what we've got so far

Full version:

anonymous

3:39 AM

@SirCumference Looks like a cartoon to me :P

Sir Cumference

anonymous

The theme is nice

The logo could be better

Sir Cumference

@anonymous Well, it's meant to differentiate us from all the other astronomy sites, in the same way as this site's Mexican hat differentiates it from every other site

anonymous

@SirCumference I get it. However, I suggest thinking of some alternative logos too before finalizing!

Sir Cumference

@anonymous Well yeah, we're still thinking :)

@anonymous Here was the last design

anonymous

3:43 AM

@SirCumference Wow! That is cool :D

Sir Cumference

@anonymous Thanks, but it still doesn't feel...StackExchange-like, at least to me :/

D3075

my design is shit ok

can we start again

it was just for a test i did it in 30 mins

Sir Cumference

@D3075 'Course

anonymous

@SirCumference Why?

Sir Cumference

@anonymous Too extravagant, maybe?

dmckee

3:45 AM

@0celo7 Strange that isn't even the gravatar that was associated with my account before I added my usual pic shortly after being elected moderator.

anonymous

Even scifi is like that. It looks cool to me!

D3075

@dmckee all the gravatars changed remember?

dmckee

@D3075 Only vaguely. I had my picture by then and was busy in "rel" life.

D3075

lol

Secret

[Esoterics] The more I read stuff in this branch of cultural phenomenon, the more I suspect these guys are basically treating as if reality is a desktop computer and they are the programmers. This is quite different from religion where the programmer is some supernatural entity, and science where we don't think of reality as a program nor us as programmers. Actually, I am not very sure where the scientific method fits in this programming analogy.

I guess we, science, are the debuggers...?

...given how our primary aim is to understand how the physics laws work and then using these models to predict the next step of what will happen

Sir Cumference

3:56 AM

@anonymous Hmm...can you test it for me, then give your opinion?

@D3075 Jesus, stop changing your name...

It's hard enough to keep track of people who regularly change their avatars, like @0celo7 or @ACuriousMind

anonymous

@SirCumference How will I test it?

Sir Cumference

@anonymous Well, do you have tampermonkey?

anonymous

@SirCumference I downloaded the extension..

Sir Cumference

@anonymous Neat. So just click here

And click "install"

anonymous

Done

then?

Sir Cumference

4:02 AM

Now check astro SE :)

anonymous

Where is the script?

Nothing is happening

Sir Cumference

@anonymous What'd ya mean?

Hmm...you on chrome?

0celo7

@SirCumference Fine.

Sir Cumference

@0celo7 No offense ._.

anonymous

I got a button there

0celo7

4:05 AM

@ACuriousMind please wake up

Sir Cumference

@anonymous Yeah, click that and check your extensions

0celo7

::algebraic topological bat signal::

@SirCumference hey if you make me an algebraic bat signal I will never make fun of you again

Sir Cumference

@0celo7 Uh...you have a sketch I can work with?

anonymous

@SirCumference It shows no script is running

Sir Cumference

@anonymous Screenshot?

Is "Astronomy SE design" there?

@D3075 Er, two questions

First, please remember to save your work

Second, can you perhaps be a bit more active?

It's been a month since we began this endeavor

anonymous

4:14 AM

docs.google.com/document/d/…

@SirCumference

Sir Cumference

@anonymous OK, click "Create a new script"

anonymous

okay

then?

Sir Cumference

Then click the tab "Installed userscripts"

anonymous

done

Sir Cumference

What do you see?

anonymous

4:16 AM

it is on

Sir Cumference

Yet it still doesn't work?

anonymous

yeah :/

Sir Cumference

Ooooohhh.....

I realized what I did wrong

All right, do Ctrl+F, and replace any "https" with "http"

Then save it with Ctrl+S

anonymous

Its working now

Except the logo is missing

Sir Cumference

@anonymous Are you sure there's no https links?

anonymous

4:21 AM

I changed them all

Using ctrl f

Ok the rest of it is working

it is nice

Sir Cumference

Thanks :)

anonymous

I will check and get back to you later

Sir Cumference

What's your opinion on the footer?

anonymous

Gotta go

Cya

Sir Cumference

All right, later

skill patrol

4:25 AM

Cya

dmckee

4:35 AM

@D3075 Only vaguely. I had my picture by then and was busy in "real" life.

skill patrol

So your avatar looks normal beside your message @dmckee

But in the top right hand corner along avatar row it is different

0celo7

@skillpatrol halp

skill patrol

What?

0celo7

If $U\subset\Bbb R^n$ open, what is the $(n-1)$-th singular homology of $U-\{x\}$?

skill patrol

Ask Ted

0celo7

4:43 AM

No

skill patrol

Why not?

How about BalarkaSen?

0celo7

asleep

skill patrol

He's in the math room now.

0celo7

@ACuriousMind $\mathrm{int}\, M\cap \partial M=\emptyset$. Proof: Let $x\in \mathrm{int}\, M\cap \partial M$. Let $U\subset M$ be a neighborhood of $x$ homeomorphic to $\Bbb R^n$. Let $H\subset U$ be homeomorphic to a half-ball with $x$ on the boundary. Let $V=U\cap H$. This is open in $M$, and in $U$, hence homeomorphic to an open set in $\Bbb R^n$.

But since $H\subset U$, we have $V=H$.

If this is true, then the $(n-1)$-th singular homologies of both must be the same if we extract $x$.

Since $H-\{x\}$ is contractible, we simply have $H_{n-1}(H-\{x\})=0$.

The claim is that $H_{n-1}(V-\{x\})\ne 0$.

The problem is that it's just some open set. But consider a sphere $S^{n-1}$ around $x$ in $V$. This is possible since $V$ is open in $\Bbb R^n$. Then $S^{n-1}\hookrightarrow\Bbb R^{n-1}-\{x\}$ is a homotopy equivalence.

However, this map is actually the composite $$S^{n-1}\hookrightarrow V-\{x\}\hookrightarrow \Bbb R^{n}-\{x\}.$$ By functoriality, the inclusion factors through $H_{n-1}(V-\{x\})$, and it must be nonzero. $\Box$

Yashas Samaga

5:09 AM

@anonymous @Koolman chat.stackexchange.com/rooms/54160/jee-preparation

0celo7

@ACuriousMind This actually gives a proof that $\pi_1(U-\{x\})\ne 1$ too.

Balarka Sen

If $U$ is homeom to $\Bbb R^n$ then $U - x$ is htpy eq to $S^{n-1}$. That is simply connected for big enough $n$ though.

@0celo7 You can't say anything whatsoever

0celo7

@BalarkaSen I can say that it's nonzero, see my wall of text.

@BalarkaSen $n=2$ in that case.

Balarka Sen

@0celo7 That I agree with.

It's just cuz there's a small ball around $x$ and removing that you have a homologically nontrivial sphere.

0celo7

I don't follow.

What's wrong with what I did?

Balarka Sen

5:21 AM

I just summarized your argument in a line.

Your work is fine

0celo7

@BalarkaSen I'm headed to bed, too much algebraic topology.

Balarka Sen

night

skill patrol

cya

anonymous

6:30 AM

@YashasSamaga Thanks for that. However, I prefer this room more. We can use that room occasionally while using heavy mathjax.

John Rennie

@ACuriousMind event horizons are globally defined iobjects i.e. you need to consider the entire spacetime to locate them. The Rindler horizon exists only for an observer who has been accelerating for an infinite time.

For what the Rindler horizon physically is see the last section of:

4

A: What is the proper way to explain the twin paradox?

Appendix - why the Rindler metric? After reading my answer you could be forgiven for feel a bit cheated because it all depends on my claim that the accelerating twin observes a spacetime described by the Rindler metric not the Minkowski metric and I did kind of pull this out of the air. It isn’...

anonymous

@YashasSamaga BTW I am not going to shift our discussions just to please a few people.

The Cryptic Cat

I am doing a mechanics course right now and I have a question that has been bothering me for quite a while.

Say i design an experiment in which i am using a system of blocks and applying forces. I perform the experiment in a specific way and repeat it. I get the same results every time I do it. Now if I got out a piece of paper and worked out using Newton's Laws what should happen, am I guaranteed to always get a unique answer to this question assuming of course that I don't forget any conditions.

@JohnRennie Could you help me out?

John Rennie

Basically yes, you will get a single solution.

There are a few few special cases like Norton's dome, but these are very much the exceptions.

There's a term for this type of time evolution that I forget, not being great on maths.

I think it's globally hyperbolic

@anonymous I've read back through last night's chat log, and basically my sympathies are with you. We sometimes get long intense conversations in this room and that's fine - that's just the way it happens sometimes.

anonymous

6:56 AM

@JohnRennie Ah, thanks for that :) I tried to explain my point to the few people who were complaining, in the most polite way possible. Some people like to build walls while I like to build bridges. Maybe that's what is wrong with me. Anyway, in case of increased peer pressure maybe I will have to follow what they say.

John Rennie

@anonymous there can be advantages to having your own room. For example you don't get distracted by conversations about food :-)

But I must admit I like discussing things here because other people may see the discussion and have something useful to contribute to it.

Once you move to a separate room no-one is going to see the discussion unless you invite them.

skill patrol

I tried to break it up to no avail :(

John Rennie

Anyhow, I've pinned skill patrol's post about the JEE Launch Pad room in case anyone is interested. I'll remove the pin in a day or so.

@skillpatrol I think in this case doing nothing would have been the best approach. You and ACM tried to help but I don't think that made things better.

skill patrol

Thanks for doing that @JohnRennie

Yashas Samaga

0

Q: Increase in mass of battery of my smartphone

The charge on my smartphone was zero. I charged my phone to its maximum capacity. How much mass $\Delta m$ did my mobile gained after charging the battery? Maximum capacity of the smartphone's battery: $2000mAh$ Weight of the smartphone with no charge: $200g$

electricity mass batteries

could that be off-topic?

skill patrol

7:05 AM

JEE Preparation

5

?

That^ is in PSE

?

The launch pad is in MSE

Yashas Samaga

oh I thought you asked me to ask about that off topic post there lol I was so confused.

skill patrol

7:07 AM

Not that it matters :-)

John Rennie

@YashasSamaga that seems a fair question

Yashas Samaga

That question needs to have that protection label I guess.

user400188

8:00 AM

So have a question I am planning to ask on Physics SE; but I am unsure what tag to use.

Kenshin

what's the question

Yashas Samaga

what's the question about?

Kenshin

ask here and i'll either tell you the answer or the tag

user400188

The topic of the question is quantum logic; which is not an existing tag: specifically, I want to know why it is necessary that the distributive law fails.

The question itself is about a page long (because i needed to include the proof that raised the question for me). As such it is somewhat unsuitable to ask in chat.

Kenshin

I think quantum mechanics could be used

DanielSank

8:05 AM

@anonymous That kind of rhetoric serves no purpose other than to 1) stroke your own ego, 2) annoy the people you're trying to "build bridges" with, and 3) Make otherwise disinterested people (like me) not really want to listen.

user400188

I'll give it a go, then write a note at the bottom suggesting the use of a new tag (quantum logic) that someone may add if they feel it is appropriate.

Kenshin

good idea

@user400188 "quantum information" is also a common tag to include quantum logic type questions

satyatech

Can any one tell me which area to consider?

user400188

I was wondering how long it would take you to move that question from Math chat to physics.

Consider adding a bit of context to the question though.

At least add that its a thermo dynamics one for instance.

Kenshin

@satyatech the first one on the left

satyatech

8:10 AM

Why can't I consider the second one any reason

Kenshin

the second one looks like VdP not PdV

satyatech

I mean can't isochoric work done be possible

Kenshin

even with isochoric work

the formula is still PdV

satyatech

How

Kenshin

work from first principles

satyatech

8:11 AM

dV =0

Kenshin

Work = Force.Displacement

use this equation to derive work in terms of V and P

satyatech

Displacement will be 0

As it is isochoric

Kenshin

if displacement is 0, then Work is 0

satyatech

Work done is PV

Kenshin

since work = force.displacement

no

work is not PV, work is force.displacement

PdV is derived from force.dispaclement which is more fundemental

gtg laterz

skullpetrol

8:12 AM

Cya

satyatech

Okk

user400188

@DanielSank Thank you for the formating edit.

John Rennie

8:30 AM

@satyatech work done is $$ W = \int_{V_1}^{V_2} P(V)dV $$ where the pressure $P$ is generally a function of volume.

anonymous

8:42 AM

@satyatech (a short proof) $W=\int F dx = \int \frac{F}{A} Adx = \int P dV$ as $P$ is the (perpendicular) force per unit area. $A$ is the area of cross section of the container (assuming it to be a regular container). So $Adx=dV$ where $V$ stands for volume.

Kenshin

@satyatech simply work is NOT change in pressure by change in volume. It is instead pressure by change in volume. Therefore it would never be VdP and only ever PdV

anonymous

@DanielSank Umm. I don't know what I should say. Sorry? No.Even my patience has limitations and it probably crossed the limits when some people are not only opposing but also vehemently disrespecting the science or physics topics I tend to discuss about. Someone gets to say "http://chat.stackexchange.com/transcript/message/35635872#35635872" and "http://chat.stackexchange.com/transcript/message/35635872#35635872". And when I say something in return that annoys you? Ok. Enough is enough.

user400188

I just realized that a significant proportion of questions with the tag "quantum-information" don't have an answer. It doesn't look good for my question at the moment.

Yashas Samaga

Is this on-topic?

0

Q: Is the radiation dose limits specified by the International Basic Safety Standards based on an experimental value?

The International Basic Safety Standards on the protection of radiation has specified the limitations on radiation exposure as for occupation and public exposure. Since there is no mention on the rationale of these values, I wonder if they are based on experimentally determined radiation dose.

radiation

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