The h Bar

Danu

21:00

@ACuriousMind You should leave that as a comment if not as an answer.

0celo7

Just ignore 90% of what I say

TanMath

ok... I guess that means no

bye then!

ACuriousMind

@0celo7 Huh? I already replied yesterday to your AssCreed question

0celo7

@ACuriousMind Welp

uh

Danu

@ACuriousMind AssCreed, nice.

0celo7

21:00

AssCreed?

You couldn't find a better name :P

ACuriousMind

That is the natural abbreviation!

0celo7

@ACuriousMind Well what about my Steam save question!?

You're my only hope, Google failed me

Danu

Why not AssAssCreed ;D

0celo7

Lock-Up_ RAW Booty Warrior FLEECE JOHNSON

►

Danu

@0celo7 [no offense intended] Can you please stop talking about Steam-related stuff? :P

0celo7

21:01

He lives by the AssCreed

ACuriousMind

@0celo7 Ah, I forgot to reply to that. In general, every game saves where it likes. I think delete local content will mostly not delete saves. Best way to find the location of saves is googling the game name + "save location".

@Danu On it

0celo7

@Danu No

I'm sure if Einstein were around he'd use Steam

Also Maxwell, Newton, etc.

@ACuriousMind Huh, first google hit for that gave me what I need, thanks

Danu

^fail

0celo7

@Danu bully

Danu

Are we holding this conversation... again?

0celo7

21:06

Yes

John Duffield

@Danu: here you go. "Eine Krümmung der Lichtstrahlen kann nämlich nur dann eintreten, wenn die Ausbreitungsgeschwindigkeit des Lichtes mit dem Orte variiert."

0celo7

What is "Ausbreitungsgeschwindigkeit"? I know what "geschwindigkeit" is and I think I know what the first part is, but what do they mean together

The spread of a null geodesic congruence?

ACuriousMind

@0celo7 It's "the speed with which something spreads"

Danu

Geschwindigkeit womit es sich ausbreitet

0celo7

@Danu No shit

@ACuriousMind Ok, so exactly what I thought

ACuriousMind

21:09

Something in this case being "light".

Danu

@0celo7 You said you didn't know the word.

0celo7

@Danu I do know the words

Forget it

Danu

After understanding my sentence you should be able to understand the word.

If you knew the sentence, you should've known the word.

0celo7

@Danu I did know the word!

Danu

"What is "Ausbreitungsgeschwindigkeit"?"

0celo7

21:11

@Danu It's the speed of spread of my ignorance

Danu

@0celo7 Hey, we don't deal with infinite things here ;)

0celo7

@Danu I've tried to renormalize it

Danu

@0celo7 I'm afraid it's an essential singularity.

0celo7

But Weinberg just confused me

Danu

In other news, there is a different Weinberg, who wrote a book on advanced QFT.

I feel bad for the guy.

0celo7

21:12

but you don't feel bad for me

wow

bully

John Duffield

A computer translation by Systrans yields "A curvature of the rays of light can enter only if the propagation speed of the light with that varies places.”

Danu

Hahaha, nice

John Duffield

Babylon gives you "A curvature of the light rays can only occur if the propagation velocity of light with the places varies."

0celo7

what are you trying to prove

John Duffield

Google gives you "A curvature of rays of light can namely only occur if the velocity of propagation of light varies with the place".

DanielSank

21:18

@TanMath You have a weird habit of mentioned problems that you have and saying things like "I have a question" rather than just *asking the $*^@( question. Just ask.

I know python, I understand something about open quantum systems.

If you just ask the question you might get an answer. If you keep saying "I wish someone knew something to help me..." you won't get anything useful.

2

This is a website for physics questions and answers. Just post your question and everything will be sparkles and butterflies.

0celo7

If a scholarship app asks for my extracurricular activities should I withhold something if I think it is politically "not liked by many people"?

TanMath

@DanielSank i have code...I have an article... the code describes the phenomena in the article. the code doesn't produce the right results. Can you revirw it? do you want a picture of the result?

here is the article:

arxiv.org/pdf/0807.0929v2.pdf

DanielSank

I'm not going to read an article for you :)

That's way too much work.

If you want to ask a question about how to model something, then just do that.

Danu

@TanMath I think that perhaps you should try to be a bit more independent.

TanMath

@DanielSank i already read it... I am wondering why the code does not work

0celo7

21:21

@Danu pls prove 1+1=3 pls

I need help :(

DanielSank

@TanMath You still haven't given us any conceivable way to help you.

TanMath

@Danu I am already independent... This is a project I am doing all by myself no professors, no fellow classmates, nothing!

John Duffield

@0celo7 : that some people will claim something isn't mainstream even though it is. That's where this little conversation started. Some people will also do a runner when cornered.

TanMath

@DanielSank I knew this was too much to ask from you... I guess the question would be, "can you look at the result and figure out where I might have gone wrong?

0celo7

@JohnDuffield wait, who disagreed that the coordinate speed of light varies

Anthony

21:26

@DanielSank Did you see my reply?

0celo7

@JohnDuffield how are you defining this speed in the first place

Anthony

In any case, for a single qubit the normal gates are $X,Y,Z,H$ right? These form a universal gate set?

DanielSank

@Anthony Maybe. You need entangling gates too though.

Anthony

What's the definition of an entangling gate?

Mike Miller

Gate you always get your shoelaces stuck in

Anthony

21:29

@MikeMiller MIKE

DanielSank

@Anthony Do you know what an entangled state is?

If not I think you may need some more basic stuff before getting into generating cat states.

Anthony

Just one that you can't write as a tensor product of two pure states, or something like this, right?

DanielSank

Yes.

0celo7

TIL hot water freezes faster than cold water

John Duffield

@0celo7 : anna v for one, see the comments here. I'm sure I could dig up plenty of other people, but I have to go I'm afraid.

TanMath

21:34

@DanielSank ?

John Duffield

@0celo7 : I'm defining the speed like Einstein defined the speed. Go and follow the references. Now I really must go.

Anthony

@DanielSank But so again, what is an entangling gate?

DanielSank

21:52

@TanMath If you want a code review post it on the site or to the code review SE site.

@Anthony A gate that produces an entangled state.

I think if you're unfamiliar with this you may want to visit the basics before getting into cat states.

TanMath

@DanielSank but I am not sure if it is appropiate with the level of physics involved and whether or not the problem is with the physics...

DanielSank

Stop pussyfutting around and try

HDE 226868

@0celo7 Votes obey rules of mathematics found elsewhere only in The Hitchhiker's Guide to the Galaxy.

TanMath

@DanielSank what?????

Slereah

Ah, topological hooey

ACuriousMind

21:56

Best kind of hooey

0celo7

22:17

@HDE226868 What's that

@Slereah what is this

HDE 226868

The Hitchhiker's Guide to the Galaxy

The Hitchhiker's Guide to the Galaxy is a comedy science fiction series created by Douglas Adams. Originally a radio comedy broadcast on BBC Radio 4 in 1978, it was later adapted to other formats, and over several years it gradually became an international multi-media phenomenon. Adaptations have included stage shows, a "trilogy" of five books published between 1979 and 1992, a sixth novel penned by Eoin Colfer in 2009, a 1981 TV series, a 1984 computer game, and three series of three-part comic book adaptations of the first three novels published by DC Comics between 1993 and 1996. There were...

I'm referencing the good ship Bistromath.

Slereah

It is from Sam and Max

HDE 226868

Sort of.

0celo7

@HDE226868 what

@Slereah why do people always reference these obscure things

HDE 226868

@0celo7 hitchhikers.wikia.com/wiki/Bistromath

Technology in The Hitchhiker's Guide to the Galaxy

The fictional universe of The Hitchhiker's Guide to the Galaxy series by Douglas Adams is a galaxy-spanning society of interacting extraterrestrial cultures. The technological level in the series is highly advanced, though often unreliable. Many technologies in the series are used to poke fun at modern life. == Sirius Cybernetics Corporation == Most of the technology mentioned in the series are products of the Sirius Cybernetics Corporation, a decidedly inept company which designs and manufactures a wide range of robots and labour-saving devices, such as lifts, automatic doors, ventilation systems...

0celo7

22:20

jesus

why do people write Wiki articles on things no one has ever heard of

HDE 226868

People have heard of them. You simply haven't.

ACuriousMind

...under which rock do you live that you don't know the Hitchhiker's Guide?

HDE 226868

Douglas Adams was the patron saint of science fiction parodies.

0celo7

@ACuriousMind dunno

I think I've heard of it

didn't know it was a thing

@ACuriousMind but haven't we already established that I live under a rock

ACuriousMind

@0celo7 Its size never ceases to astound me :P

0celo7

22:28

I have never seen Lost

My parents have the box set around here somewhere...

Danu

Now that

is something people won't really be weirded about by :)

0celo7

huh?

Lost was hugely popular back in the day, wasn't it?

ACuriousMind

@0celo7 Yes, but it is not something often quoted, mimicked, or otherwise referred to.

0celo7

@ACuriousMind ok

what is?

i.e. what should I watch

ACuriousMind

While I can't imagine how many puzzling things you've heard about towels if you don't know Hitchhiker's Guide ;)

0celo7

22:33

Can't say I've ever heard of a puzzling towel before.

HDE 226868

Now that someone besides 0celo7 is in the room, I'll re-ask my question from yesterday:

20 hours ago, by HDE 226868

Is anyone familiar with the "modulus of precision" of a Gaussian distribution?

It came up relating to a velocity distribution.

ACuriousMind

@HDE226868 Is that a strange way to speak about its standard deviation? :P

(that means: "No, I'm not familiar with that" ;) )

0celo7

@HDE226868 see ACM doesn't know either

It's a made up term

HDE 226868

@ACuriousMind I don't think so.

Danu

So what is the definition?

HDE 226868

22:41

No idea. It's just used in one of a series of papers as the name of one variable and is never explained again (although I'm only on the third of at least five).

Mike Miller

@Slereah: I liked seasons 1 and 2 better.

HDE 226868

> The velocity distribution of the other stars is taken to be isotropic and Gaussian, with modulus of precision $j$. The independent variable $x$ is a scaled velocity,$$x=jv$$

King (1965)

ACuriousMind

@HDE226868: Have a look at this

I believe your "modulus of precision" is just the inverse of the variance, i.e. $1/\sigma^2$, perhaps with some pre-factor.

Here's another Wiki article that has "precision" as the inverse of the variance.

Danu

I found it here

> MODULUS (in the Theory of Errors). In his first theory of least squares based on the normal distribution and presented in Gauss’s Theoria Motus Corporum Coelestium in Sectionibus Conicis Solem Ambientum (1809) Gauss used a measure of precision ("mensura praecisionis observationum" (p. 245) which he denoted by h: the reciprocal of h is √2σ, where σ is the standard deviation. Both h and its reciprocal have been called the modulus [...]

ACuriousMind

@Danu That's a reference to the "Precision" Wiki article.

Danu

22:51

@ACuriousMind I know.

But this is the precise quote from the reference :P

HDE 226868

@ACuriousMind I had looked there, but I didn't think it could be that simple.

@Danu I love that site!

Thanks, guys.

0celo7

23:06

@ACuriousMind What's your top 3 list of things a sub-rock-dweller should watch

@ACuriousMind $g_{ab,cd}=R_{abcd}\cdots$ cannot hold because the LHS is not a tensor but the RHS is

is this not a simpler explanation?

Danu

well

he says explicitly he doesn't care about what is in the dots

so it doesn't have to be a tensor

0celo7

it has to be a Riemann tensor

or a Ricci tensor

Danu

I think the other agrument is better

ACuriousMind

@0celo7 Top 3 to get references or Top 3 to watch something good? Also, my tastes are probably a bit too SciFi/Fantasy-heavy

0celo7

otherwise what ACM says is wrong

Danu

23:11

Didn't he say it can be anything?

0celo7

then ACM's is wrong

it could be $R_{abcd}+$something not involving curvature

ACuriousMind

@0celo7 Now that you say it, that is more straightforward, yes

@Danu Well, they accepted my answer, so I guess they really meant "a polynomial in components of $R$" by "anything" :P

Danu

yup

0celo7

I added an answer

yolo

Now, one can do a normal coordinate expansion of $g_{ij}$ to all orders...and taking derivatives of this would give $g_{ij,kl}$ in terms of Riemann and friends

but its not a polynomial in R

DanielSank

@TanMath I mean just ask your question.

Post the code.

Give the people whose help you want some possible avenue of helping you.

0celo7

23:19

@ACuriousMind The first.

I already have a mega list of good stuff to watch

(still making my way through a 300 episode Skyrim lets play)

(yes, I am addicted to Skyrim)

ACuriousMind

@0celo7 Hmmm. Okay. Then one item on the list is everything by Monty Python ( not-so-obligatory early xkcd ).

0celo7

I've watched one or two of those. They're OK.

ACuriousMind

I'm not really sure what to pick for the other two things...

0celo7

@ACuriousMind I don't get that one.

First time I haven't understood an xkcd in a long time.

Holy Grail? I watched that.

But my memory is too poor to be able to remember quotes like that.

ACuriousMind

@0celo7 Well, apparently you know no people who have the irritating tendency to turn a conversation into a Monty Python quote-fest, then

0celo7

23:24

@ACuriousMind I can confirm this...

HDE 226868

@ACuriousMind That happened in the Teachers' Lounge once, when everyone was pissed off at the folks in the C++ Lounge.

0celo7

Are there people like that? Or is xkcd man making this up

ACuriousMind

@0celo7 There are people like that. Trust me.

0celo7

Yeesh

ACuriousMind

If there's more than one of them at a party, the challenge is to get them into the same room, have everybody else leave, then close the door.

Emilio Pisanty

23:27

Hey folks, here's a puzzle

Why does this user have 6 reputation?

tjsb55

6

support

Given that on the main site,

tjsb55

1

they have 1 rep?

ACuriousMind

That's very strange

HDE 226868

Caching?

Emilio Pisanty

@HDE226868 Could be. Like an upvoted but deleted answer on main which has yet to propagate to the meta rep?

0celo7

Probably one of @DanielSank 's puppets

He messed up the coding

HDE 226868

@EmilioPisanty That's my bet (well, it would be a question, for +5).

Emilio Pisanty

23:29

@HDE226868 Yeah, it makes sense, good catch.

No firm evidence for it unless a mod can confirm the deleted question, but if the meta user drops down to 1 after a day or so then that'll tell what's going on.

0celo7

Emilio Pisanty

(nudge, nudge, @mods)

0celo7

@ACuriousMind Nice paint circle

HDE 226868

@EmilioPisanty Caching is always the answer.

Emilio Pisanty

@HDE226868 Indeed it seems to be

0celo7

23:34

@HDE226868 why does AC4 run so slow on my laptop

HDE 226868

> We really aggressively cache... basically everything.

@0celo7 What's AC4?

0celo7

@HDE226868 AssCreed 4 Black Flag

HDE 226868

Yeah, no idea what that is.

0celo7

remove the last "l" and the title is a whole lot more fun

TanMath

@DanielSank i will write a code review post...

0celo7

23:36

@HDE226868 oh, so caching is not the answer

wait

you're a teenage male American and you don't know what Assassin's Creed is?

We played that in middle school for Pete's sake

in a small German village!

HDE 226868

And people wonder why the juvenile delinquent system is so full. . .

0celo7

???

HDE 226868

Nothing quite like showing a bunch of kids how to shoot stuff in a game.

0celo7

Oh jesus

ACuriousMind

@0celo7 I'm very proud of that, thanks!

0celo7

23:37

You STAB people

0537

It's a big difference.

0celo7

it's a game about STABBING and SLICING fools

although in later installments there are guns and crossbows

ACuriousMind

In case you didn't know, freehand circles are a tradition for meta posts.

0celo7

@ACuriousMind Does any Lie group admit a canonical Riem. metric by using the Killing form of the Lie algebra

ACuriousMind

@0celo7 Only if the Killing form is non-degenerate, i.e. only for semisimple Lie groups.

0celo7

23:47

@ACuriousMind tries to remember Uh, are those the "standard" ones?

ACuriousMind

Yes

0celo7

@ACuriousMind if $G,H$ are Lie groups, is $G\rtimes H$ also a Lie group

@ACuriousMind Well, let's try $G\times H$ first. I know it's true in that case.

(call this one $K$) Is it possible to write the canonical metric on $K$ in terms of those on $G,H$

ACuriousMind

@0celo7 Yes, iff the twisting map (or whatever you call the $G\to \mathrm{Aut}(H)$ belonging to the semidirect product) is a Lie group homomorphism.

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