The h Bar

Sir Cumference

12:00 AM

Sorry for my ignorance

Danu

Perhaps you should try to check out Mukhanov's book on cosmology

chapter 3

Sir Cumference

Er, any quick explanation?

Danu

Don't remember :)

"quick explanation" + physics = bad times

ACuriousMind

@SirCumference Because the light cone doesn't care how fast things are moving now

Sir Cumference

I know

ACuriousMind

12:05 AM

The Hubble sphere looks at where things are now. The light cone looks at whether or not the spacetime distance between us and that event is timelike or not.

Sir Cumference

So we can see the objects beyond the Hubble sphere based on what they looked like when they were within the Hubble sphere?

ACuriousMind

Only if the Hubble parameter is constant you can infer from the distance now that they must always have been receding faster than light. But it isn't constant, so there is a priori no relation between the Hubble sphere and the light cone

@SirCumference Yes.

Sir Cumference

THERE WE GO

Dang, it should've been so simple

Can't believe I didn't realize it

Eventually, won't we be unable to see those objects?

ACuriousMind

Eventually, yes. Why is there a "but" there, does that contradict anything?

Sir Cumference

What are you talking about?

ACuriousMind

12:10 AM

Being in this chat has made me realize why many chats do not allow editing :P

Sir Cumference

Anyways, back to my question. When objects go beyond the point when we won't be able to see them, will their gravity still affect us?

ACuriousMind

@SirCumference No, because they will be outside our light cone.

0celo7

@user36790 Ok, finished AC Rogue. One of the shortest ACs!

Sir Cumference

Dang, all this makes sense now!

Thanks a lot

0celo7

@user36790 I don't really know how to rank Rogue.

I think they made some important tweaks to the mechanics of 4.

The story was ok, it could have been longer.

Hmm, I take that back.

Like ME2, once you get to thinking about it, the story is based on stupidity.

0celo7

12:37 AM

20 minute credits

OK Ubisoft!

Just end already holy crap

Physics Meta

12:51 AM

0

Q: Has the "soft-question" tag become a bad idea?

I took a quick peek at the newest 'soft-question' questions when I noticed something particularly disturbing, most of them are marked either as [closed] or [duplicate]. There were so many that I thought it worth the while to bring it to mention. I suggest looking through the first 10 pages of t...

user507974

@0celo7 lol, but how would they give credit to all the people who copy pasted code from one project file to another?

0celo7

@user507974 The engine and most of the assets are taken directly from 3 and 4.

@user36790 Yeah, the story was crap.

Nice idea, but poorly executed.

And there should have been a twist.

Haytham should have murdered Shay.

user507974

@0celo7 the apples really have cookies in them all along

0celo7

1:07 AM

@user507974 Interesting theory

There are no Apples in Rogue

So it doesn't work

0celo7

2:01 AM

@BernardMeurer ikr

@BernardMeurer wtf

Bernard Meurer

@0celo7 What?

0celo7

7 hours ago, by Bernard Meurer

@FenderLesPaul Yeah he is, he's bloody useless

Bernard Meurer

@0celo7 Couldn't help it

0celo7

@BernardMeurer I do so much nice shit for you and this is what I get

Stalking and instults?

Bernard Meurer

I display love that way

0celo7

2:15 AM

@BernardMeurer (a) eww, gay (b) I don't want that kind of love

Bernard Meurer

@0celo7 Rebecca gives you the other kind already

0celo7

@BernardMeurer Dude

wtf is up with this trackpad

on my old laptop

Bernard Meurer

2:33 AM

@0celo7 Dunno, what are the symptoms?

user116211

@ChrisWhite: Let's standardize with o. Vote up if you agree.

user116211

Was I expected to see this only?

user116211

If so, then yes, it's pretty clear to me.

0celo7

@BernardMeurer Check snap

Ignore dirt

user116211

@ChrisWhite: Also, I'm also able to see Duffield's answer

0celo7

2:35 AM

It's been rotting for the past 9 months.

Bernard Meurer

@0celo7 Who are you saying stop to?

And I don't see what's wrong with it

0celo7

@BernardMeurer That's probably my roommate

You don't see that it's stuck out of the frame?

Bernard Meurer

@0celo7 The one that watches porn?

0celo7

@BernardMeurer What?

@BernardMeurer According to Google the battery is swelling.

Bernard Meurer

@0celo7 Very logical

user116211

2:49 AM

@0celo7: You finished Rogue?

0celo7

@user36790 Yes.

user116211

@0celo7 Then really it is the shortest. I never could have completed the AC in such a short time.

0celo7

@user36790 Yup. It's not like I no-lifed it either.

user116211

@0celo7 I would prefer to play Mortal Kombat then;/

0celo7

3:16 AM

@user36790 Huh?

It was a good game.

I might continue playing -- I haven't even come close to exploring all of the world

0celo7

3:32 AM

@ACuriousMind Oh my god I found a video of me from the fifth grade

My German was so good :'(

user116211

@0celo7 What video?

user116211

@0celo7 Is it better than 4?

0celo7

@user36790 No, I liked 4's story better.

user116211

@0celo7: Have you played AC chronicle?

0celo7

I don't think so.

Bernard Meurer

3:41 AM

Something horrible just happened

user116211

@BernardMeurer What?

Bernard Meurer

I made a bash code that performs the same task as my python code. But in less lines

How can this be? Where did I fail?

0celo7

@BernardMeurer The trackpad is still growing

Bernard Meurer

@0celo7 That shit's blowing up

0celo7

Yes.

user116211

3:44 AM

@0celo7 read the novel; it was nice but didn't know it was turned into game.

Bernard Meurer

@0celo7 What do you think of (this code)[github.com/bemeurer/pip-upgrade/blob/master/pip-upgrade.sh] ?

0celo7

404

Bernard Meurer

github.com/bemeurer/pip-upgrade/blob/master/pip-upgrade.sh

And this one github.com/bemeurer/pip-upgrade/blob/master/pip-upgrade.py ?

user116211

@0celo7: The game has 3 mini-series: China; India; Russia.

user116211

Assassin Shao Jan was trained by Ezio!

user116211

3:50 AM

We get Arbaaz Mir from India.

user116211

Far better looking than Connor.

user116211

And finally the Bolshevik Revolution in Tsar's Russia.

0celo7

@BernardMeurer what am I looking at?

ask my sister

user116211

But the storyline is below the par.

user116211

I made a shot as the price was lower than AC Rogue.

Bernard Meurer

3:53 AM

She knows code. I wan't that to be clear even for someone who doesn't

you're looking at a code that get's the output of a command "pip list -o" (list outdated packages)

filters all the garbage out to only keep the package names

and upgrades all the packages

Read them comments

0celo7

I'm busy

Bernard Meurer

@user36790 Do you mind giving me a hand?

user116211

@BernardMeurer Man, I'm studying, sorry ;/

user116211

Inorganic Chemistry , I hate it.

Bernard Meurer

Sigh, I'll go ask my code review AI then

user116211

3:58 AM

@BernardMeurer: Froth floatation Process, wanna read it?

Bernard Meurer

Sure, have you got a pdf?

user116211

@BernardMeurer WTF?

user116211

Okay, then comes Bessemerisation process to produce blister copper, you wanna read it?

0celo7

@ACuriousMind I now have proof I was in Germany.

user116211

Froth flotation

Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing industries. Historically this was first used in the mining industry, where it was one of the great enabling technologies of the 20th century. It has been described as "the single most important operation used for the recovery and upgrading of sulfide ores". The development of froth flotation improved the recovery of valuable minerals, such as copper- and lead-bearing minerals. Along with mechanized mining, it allowed the economic recovery of valuable metals from much...

0celo7

4:02 AM

Unless there's some other Ryan who lived in the Pfalz with my voice but eunuch-level

user116211

@BernardMeurer: This process is used to extract Hg.

user116211

Why the hell you want to read it?

Bernard Meurer

@user36790 Quit spoiling dude! You just ruined the end of the paper

0celo7

@BernardMeurer Remember that ashy girl who had a crush on me

I have a picture

I have all the pictures now

Bernard Meurer

@user36790 I like reading :p

user116211

4:04 AM

@BernardMeurer I'm suffering a lot and you want a pdf?

Bernard Meurer

@0celo7 The crazy one?

0celo7

@BernardMeurer no

forget it

user116211

@BernardMeurer When will our country's syllabus maker understand not everyone has to study these craps?

Bernard Meurer

NO

@user36790 Yeah if you have a pdf :)

user116211

@BernardMeurer: You like inorganic chem??

Bernard Meurer

4:06 AM

Better than organic I do

But I also like leprosy better than organic chemistry

user116211

@BernardMeurer chem.mtu.edu/chem_eng/faculty/kawatra/…

Bernard Meurer

Thanks, I'll definitely take a look at it

user116211

@BernardMeurer Don't look; it's darn depressing

user116211

I can't even remember those shitty metallurgy craps.

Bernard Meurer

@user36790 Assembly is depressing

user116211

4:10 AM

I could only remember Harbey Process, that's it.

user116211

Why do we need to study these industrial chem?

user116211

There is nothing but cramming reactions and vomiting it in exam sheets; that's it. They are over.

0celo7

@BernardMeurer youtube.com/watch?v=KwX46eNDd2s

Found this in my old music

0celo7

5:13 AM

@ACuriousMind Tfw 10-yo me knows the word for "rape" in German

wtf

user116211

@0celo7 o.O

0celo7

oh man 10yo me was profane too

No one will ever see these videos

Bernard Meurer

@0celo7 The best pic of you is that one passed out on the grass

0celo7

That never happened

user116211

@0celo7 it's not unholy.

0celo7

5:19 AM

@user36790 wha

user116211

@0celo7 10 yr old is nothing. I've classmates who are accustomed to this even before.

user116211

And it's natural.

user116211

5:46 AM

@DavidZ: You liked the recent font change?

David Z

@user36790 I definitely like that we have a serif font now, so that the math matches body text better

user116211

@DavidZ it's enchanting ;D

user116211

@DavidZ I can gaze at it for hours; they are so beautiful.

user116211

Prior to that, the look was horrendous.

David Z

I'm not really a fan of the specific font they chose, but it's good enough

Bernard Meurer

5:58 AM

Everyone should just use Wingdings

user116211

@BernardMeurer 3?

Bernard Meurer

I'm a purist, Wingdings 1

user116211

o.O

Slereah

8:17 AM

Guys

I rechecked my Gromm and Jaffacake

Do the axioms of QFT actually specify a direction of time?

There's the reflexion positivity axiom that deals with time reversal, is that the one that implies it or...

Danu

I want to say that there is no arrow of time on the microscopic level (hence my earlier statement about it having to do with entropy)

Slereah

Well yes, but

Particles are on a specific small group of the Lorentz group, no?

Danu

But I understand we need to get retarded Green functions somehow

Slereah

With momentum in the future light cone

Danu

Well, idk

You know that Feynman propagators (the one we usually work with in non-thermal qft) are time-symmetric

I'd bet my money on there not being any arrow of time in regular QFT

Slereah

8:21 AM

yeah

Hm

Maybe this should be a SE question

Danu

Moretti has been posting really nice answers to QFT axiom questions

user116211

@Danu I want to be Moretti ;D

Danu

I don't like the stuff he's most into

user116211

@Danu He is a mathematical physicist, right?

Slereah

8:37 AM

Hey @valter-moretti what's up with that thing I said

Danu

@Slereah Do you want him pinged? I can ping him if you'd like.

Slereah

Ping away

Danu

(I'm not going to ping him if you don't really have anything to say to him)

Secret

8:55 AM

arxiv.org/abs/1509.02749

Asymmetry is the way to go...?

NB "...?" is not a question

Slereah

Oh well

I suppose I'll make a question when I get home

Check the books before just in case

innisfree

@secret interesting. If you tell it you haven't performed any experiments, will it tell you to do eg Bell type ones?

GPhys

glances up "Perpetual motion machine"

The titles of questions in the news feed give me high blood pressure.

Slereah

It is quite a red flag

Red flag topics are like

Perpetual motion

Interpretation of QM

Quantum gravity

Time travel

Hm, what else

Entanglement also gets a lot of odd questions

FTL travel

Black holes

yuggib

@user36790 you want to be italian?

Danu

9:06 AM

lol

user116211

@yuggib damn lol

yuggib

@user36790 also be careful not to become the wrong moretti...

user116211

@yuggib huh?

yuggib

en.m.wikipedia.org/wiki/Nanni_Moretti

user116211

@yuggib remove m

user116211

9:15 AM

@yuggib i thought some darn ISIS guy :P

yuggib

Birra Moretti

Birra Moretti was an Italian brewing company, founded in Udine in 1859 by Luigi Moretti. In 1996 the company was acquired by Heineken International. The brewing plant in Udine was sold to the newly formed Birra Castello S.p.A.; Moretti is now a brand of Heineken. == Brands == There are six beers under the Birra Moretti brand. Birra Moretti is the main brand, a 4.6% abv pale lager launched in 1859; followed by La Rossa, a 7.2% strong dark lager or doppelbock. Other brands include Baffo d'Oro, Doppio Malto and Sans Souci. == See also == List of Italian companies Heineken brands#Birra Moretti �...

you have plenty of Morettis

user116211

@yuggib: remove m from the link.

yuggib

what?

ah I see

user116211

@yuggib The links you are giving are mobile compatible...

user116211

Now, check this guy:

user116211

9:17 AM

Ted Kaczynski

Theodore John "Ted" Kaczynski (/kəˈzɪnski/; born May 22, 1942), also known as the "Unabomber", is an American anarchist and serial killer. Between 1978 and 1995, Kaczynski engaged in a nationwide bombing campaign against people involved with modern technology, planting or mailing numerous homemade bombs, ultimately killing a total of three people and injuring 23 others. He is also known for his wide-ranging social critiques, which opposed industrialization and modern technology while advancing a nature-centered form of anarchism. Kaczynski was born and raised in Evergreen Park, Illinois. While...

yuggib

for one is too late...

user116211

^^^ the genius who bombed??!!

yuggib

9:39 AM

@user36790 there are also evil geniuses...

Slereah

9:50 AM

My favorite thing about Kaczynski is that one time, I was reading a math paper

And it mentionned Kaczynski

And it was like "Ted Kaczynski, known among other thing for his work on [math things]"

skull petrol

10:10 AM

another notorious Ted

murderpedia.org/male.S/s/streleski-theodore.htm

Theodore Streleski

Theodore Landon "Ted" Streleski (born 1936) is an American former graduate student in mathematics at Stanford University who murdered his former faculty advisor, Professor Karel de Leeuw, with a ball-peen hammer on August 18, 1978. Shortly after the murder, Streleski turned himself in to the authorities, claiming he felt the murder was justifiable homicide because de Leeuw had withheld departmental awards from him, demeaned Streleski in front of his peers, and refused his requests for financial support. Streleski was in his 19th year pursuing his doctorate in the mathematics department, alternating...

Slereah

10:44 AM

Hm wait

I seem to recall specifically that AQFT cannot work in non-time orientable spacetimes

Which means that a time orientation might be necessary?

Might be related to the time slice axiom?

Secret

I am not sure. Skim reading the paper suggest they feed the program with a target state (e.g. something called GHZ) and ask the program to came up elements that can produce this state

So I guess you need to at least have some goal in mind for it to work...?

user116211

11:01 AM

I didn't get this:

user116211

2

Q: Twisted partition function in conformal field theory

$%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%$

conformal-field-theory partition-function

user116211

Why is he doing so?

yuggib

he added an image

either he does not know how to type latex on SE, or does not know how to type latex at all

user116211

No, I edited it; check revisions:

user116211

physics.stackexchange.com/posts/239224/revisions

user116211

11:05 AM

I removed the pic, wrote the equations in mathjax; but he rollback to the image.

user116211

Why?

yuggib

T__T

don't know

I can reroll back again to the one with forumlas

user116211

@yuggib do it but he will again re-roll it.

yuggib

I did it, and added a comment ;-)

let's see

user116211

That's it; deleted.

yuggib

11:15 AM

some people are strange

user116211

He has some problems, I think; he knows LaTeX; as he by himself wrote his first equation using Mathjax.

yuggib

who knows...also, he probably wrote the latex file and complied it in pdf form to produce the pic

user116211

@yuggib But why? It's like killing a mosquito with an atom bomb ;/

yuggib

@user36790 more or less...that was also the comment of my PhD advisor concerning how I solved a ODE problem with the implicit function theorem on Banach spaces :-þ

user116211

@yuggib Great men think alike ;P

yuggib

11:22 AM

(he said "cannon" instead of "atom bomb")

@user36790 indeed

user116211

@yuggib it was looming in my mind.

Danu

12:57 PM

Anyone who feels like helping me out in some subtle construction in algebraic topology:

0

Q: A technical detail in the construction of a covering space: Is the projection $p$ continuous without assuming semilocal simple connectedness?

I am studying the construction of a covering space with prescribed characteristic subgroup. For simplicity, I will outline the case where the characteristic subgroup is trivial (i.e. we're dealing with the universal cover). Note that the following is very similar, but not identical to the section...

algebraic-topology covering-spaces fundamental-groups

0

A: Has the "soft-question" tag become a bad idea?

Upvote this answer if you think soft-question should be burninated (i.e. all instances removed, and making it unavailable for future askers), or downvote it if you think that that's a bad idea.

Let's burninate soft-question

New hobby: Going through "famous questions" and VTCing the off-topic ones.

Danu

1:16 PM

@DavidZ What do you think about the answers here. Solutions to homework question?

Should they be deleted according to the current policies?

Really checking out the famous questions list is really bad for one's believe in the usefulness of this site, hahaha

user116211

@Danu I really don't think this is hw. This is one of the problems faced by a novice who starts physics without stern grasp on calculus.

yuggib

journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.160505

Danu

@user36790 Like... homework? :P

(you don't have to agree with me)

user116211

@Danu yeh ;)

yuggib

^^ Poll: good or bad physics? In my opinion it is mostly a recreational topic, but nice

user116211

1:26 PM

@Danu: Gave my vote to burn that soft tag; but nullified by a simultaneous downvote ;/

John Duffield

@user36790 : which answer to which question? This answer to this question? That hasn't been "rotting" for nine months.

user116211

@JohnDuffield yes, I was talking about this.

user116211

@JohnDuffield Who said rotting?

Danu

lol

user116211

John Duffield

1:38 PM

@user36790 : Ocelo7 said something about rotting here maybe he was talking about something else.

user116211

@JohnDuffield Oh! here he comes.

user116211

@JohnDuffield If you're not sure, then please don't impose something of someone to someother without understanding that something.

John Duffield

I don't like the serif font. It looks old fashioned.

user116211

@JohnDuffield at least it is better than the prev

John Duffield

I beg to differ. I like lean clean sans-serif fonts.

@user36790 : like, impose what?

0celo7

1:42 PM

@JohnDuffield What?

John Duffield

What's been rotting for nine months?

0celo7

My old laptop.

user116211

@JohnDuffield you think nine month rotten....

John Duffield

@0celo7 : OK noted.

0celo7

@JohnDuffield Uh, ok?

user116211

1:43 PM

@0celo7 duffield thought something else, I guess.

John Duffield

Yep. So what's all this stuff about imposing something without understanding it?

user116211

@JohnDuffield oogh! You imposed that nine month on me for what reason?

John Duffield

@user36790 Huh? A passing comment is not some imposition.

user116211

@JohnDuffield OOOkkkay! You win. I surrender. All my fault.

user116211

Don't ping again on this.

John Duffield

1:51 PM

@user36790 : Good, do you surrender on the electromagnetic field too?

@user36790 : oops, too late.

0celo7

I would ask what EM thing, but we'd probably get banned.

user116211

@JohnDuffield Victory is yours; argument with you is futile. You Win!!

yuggib

proof by exhaustion...

2

David Z

@Danu agreed with user36790, it's not a homework question - though it is low-effort.

Danu

@DavidZ Alright.

John Duffield

1:58 PM

@0celo7 : the EM thing in his question, where he said since the charges are moving, they would create magnetic field B. The point to note is that motion is relative: you don't create a magnetic field for an electron just because you moved. In similar vein you don't create a magnetic field for the electron by moving it.

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