UK plus áéíóúÁÉÍÓÚñÑ for Spanish

and while I was there tinkering I added some goodies

@JohnRennie Yes, the problem I'm having is that I seem to have run out of existing models to use. I've already had them do it for Lennard-Jones and Morse, and Buckingham doesn't have a simple expression for the equilibrium separation. Those are basically the three I know of. So I was hoping someone knew another one that might actually be encountered in a realistic setting.

ħ ⟨ ⟩ ≤ ≥ ≠ ± §

⟨ and ⟩ are particularly useful

both in standard text and inside mathjax

even though @DanielSank hates me for it

oooh, also ¡ and ¿ for Spanish

↑ best punctuation mark not in the English language

@ChrisWhite Hah, no idea

Spanish just has those two

@EmilioPisanty I don't hate you for it, I just find it 1) ugly and 2) less useful than using mathjax macros.

But being able to mark the start of a question can be quite handy

@EmilioPisanty Agreed.

@DanielSank But it is a mathjax macro ;-). TBH I'm using it less nowadays, only on bigger posts. And never on other people's posts.

@ChrisWhite Hehehe, that's pretty good.

Actually used by any language?

@EmilioPisanty I just don't see a problem with using macros. I figure since they're supproted they're probably part of the mathjax spec.

Although I suppose if someone were to download the SE database and try to render the posts locally with TeX having macros defined inline would be no bueno.

I may need to reconsider my position.

@DanielSank Yeah, my reasoning is along those lines. Markdown is meant to be a language that displays nicely when rendered but is also human-readable at source level. MathJax support for e.g. ⟨⟩≤≥±≠° plus unicode greek letters is completely along those lines.

@EmilioPisanty Indeed.

Particularly since it's relatively straightforward to do the correspondence.

@EmilioPisanty If only I could type those damn unicode characters.

(Purist TeX objections to e.g. unary and binary ~ being different aside.)

Actually I think the situation is trickier than either of us is saying.

@DanielSank Yeah. The ones I can type I do. I don't think it's worthwhile to build a Greek keyboard though.

SE posts are not just markdown. They're close, but they're really markdown + mathjax.

The introduces a tension between what's purely correct and what's practical.

So yeah, vanilla markdown renderer will display some stuff right, but the equations will look like this:

$$i \partial_t \left \levert \psi \right \rangle = ...

@DanielSank Yeah. But MathJax ≶ TeX

@EmilioPisanty Indeed.

@ChrisWhite Not a punctuation mark, but in the running for best symbol ever:

math.utah.edu/~palais/pi.pdf

Oh, yeah, $\pi$ is a dumb constant.

The 2 pi symbol is usually written $\tau$

Should have been $2 \pi$.

@Slereah That is not "universal".

@Slereah Yeah, but $\tau$ is such a pale choice compared to three-legged-pi

I've seen the three legged pi more.

I've never seen this...mutant

yeah but tau is in unicode at least :p

@ChrisWhite I've never seen it used in anger.

@ACuriousMind and yeah, it very much looks mutant

Well before like the renaissance, there was little difference between astronomy and astrology

Hm, what odd symbols do I know

I once read a math paper that used hearts as symbols

Would it be mean to suggest that a post should be moved to Worldbuilding and given the [technobabble-based] tag?

Depends which post

Nah, my posts tend to be pretty boring mathy ones :p

I mean, they are full of technobabble, but I cleverly disguise them

@dmckee Yes. That doesn't mean it's not also appropriate.

I never tag any CTC question I have with time-travel

Link fixed. Down-voters please reconsider.

lol, no

And I don't know anyone who has

Most fraternities don't duel anymore

And of those who duel, only a few duel such that you might get scars

@ChrisWhite As an ex-sabreur I am compelled to point out that saber is simply more fun.

:)

@ChrisWhite I think the German Wikipedia is telling me the student fraternities chose the sabre because it's what the military used for its duels.

@ACuriousMind Pffft. Lame.

Oh, oops, I mean awesome!

@ChrisWhite Foil is awesome to watch though.

I have to admit that.

High level saber points are disappointingly short.

imdb.com/title/tt0075968/?ref_=fn_al_tt_1

↑ While we're at this

Awesome movie

@ChrisWhite the best kind of duel

Although I say

A proper gentleman duels with a lance

Hey everyone, we have a Q over on Crypto.SE about the maximal possible amount of orthognal states of a quantum "bit" (e.g. qutrits, qubits, ...). While this would certainly be interesting from a cryptographic standpoint and we may be able to answer it, do you guys here want it (and are chances high you can provide a good answer here)? The Q in question

@SEJPM There is no "maximal possible amount" of orthogonal states for quantum systems. It's just a question of how "large" a system we can engineer over which we can still exert the control required for using it in quantum information. I'm not sure if we want that question here - there's no physics to discuss that I can see.

@SEJPM @DanielSank May be able to help

> I'm not sure if you're aware, but these fraternities and their traditions are met with derision or disgust by a great majority in modern German society.

@ACuriousMind Where did Germany go wrong?

Weren't germans seen as pretty unmanly before WWII

@SEJPM It's probably easier for one of us to answer it over there and leave it at that. Unless it's actually off-topic on your end; it's not particularly on topic here.

TCS also takes quantum information questions, it may be a better home than here.

@EmilioPisanty that sounds like a reasonable course of action.

@0celo7 Nowhere. What's supposed to be wrong with that?

So if any of you want to answer it, feel free (as you always should on SE :)

@SEJPM Way ahead of you.

damn, too slow :)

@EmilioPisanty why restrict to separable spaces? ;-P

@yuggib Hence 'usually'

But if you can point me to a non-separable one used to describe an actual quantum system I'll change it.

@EmilioPisanty well, the algebra of canonical commutation relations is non-separable

it is not a Hilbert space however ;-)

@Slereah Abe Lincoln is said to have accepted a duel, and as the challenged party got to select the weapons. "Broadswords in a pit". At which point the Challenger demurred.

Just pick "Suicide vest"

It will deflate most conflicts

@DanielSank could you explain "write down the equations of motion in dimensionless form"?

Change the variables and constants so that everything is dimensionless

@TanMath Yes of course.

Suppose you have $i \hbar \partial_t |\Psi\rangle = H |\Psi\rangle$.

This equation has demensions on both sides.

$\hbar$ has dimensions of action.

$\partial_t$ has dimensions of 1/time.

Therefore, the left side has dimensions of action/time = energy.

Obviously $H$ also has dimensions of energy.

This is good. The dimensions match.

However, this is bad for numerics.

It's bad because you have absolutely no idea how big to make your time steps.

The best way to fix this is get rid of all the dimensions.

First step is divide everything by $\hbar$ so you get:

$i \partial_t |\Psi(t)\rangle = (H/\hbar) | \Psi(t)\rangle$

Now both sides have dimensions of 1/time.

@DanielSank make them $\epsilon$

You can already tell what to do at this stage. You get frequency scales from $H/\hbar$, so you can just pick your time step to be say 10x smaller than the largest frequency.

@DanielSank why not just set $\hbar=1$

@0celo7 Go away.

wtf

@TanMath moving on...

The other thing you can do is define a time step $\delta t$ and then write:

$\tau \equiv t/\delta t$

$\tau$ is now dimensionless.

So now you can write

$\partial_t \equiv (d/dt) = (1/\delta t) (d/d\tau)$

Then Schrodinger's equation is

$i (d/d\tau) |\Psi\rangle = (\delta t H / \hbar) |\Psi\rangle$

Here $\tau$ is your dimensionless time variable in your computer simulation.

$(\delta t H / \hbar)$ is dimensionless. You need this because the floating point numbers in your numerical simulation are just numbers. They too are dimensionless.

So now your only job is to choose $\delta t$ small enough that $(\delta t H / \hbar)$ is small enough to give small changes for each time step.

@0celo7 Meaningless post.

@DanielSank no

@0celo7 How is that supposed to help explain anything?

@0celo7 Yes. What's $\epsilon$? You just posted some random distracting comment without offering any information.

You do this all the time and I wish you'd stop.

@DanielSank epsilon is a small number obviouslt

I've never done that

now you're gonna get mad and block me

@TanMath in other words pick $\delta t$ such that $\delta t H / \hbar \ll 1$.

I have to do a minor surgery. Dammit, I'm so sad.

I'm scared too.

@3075 Dammit man

@3075 When's it going to be?

Tomorrow morning.

Oh wow that's quick

You know the name of what they're doing?

Idk the name but

They're basically putting a tube in my lung for a few days. To inflate it and remove the air that escaped.

So I'll have a damn tube inside of me for a few days while I'm conscious.

Right now I'm on oxygen otherwise I'll turn blue and become dizzy.

Lol

@BernardMeurer my new 3ds already has a damn scratch on the screen

how is that even possible

@0celo7 Crap materials

@3075 Hardcore man

Should be your lesson: Don't brush teeth

I think I've gone on long enough without working out

Time to work on my mooscles

I don't know if I should do local or general anesthesia.

Going to sleep is scary af

If you have to stay in the hospital a while, I'd say go general

You're gonna sleep like a baby for a bit

I'll be staying for 3 days at least.

The time I got general anesthesia I basically drifted in and out of sleep all day long

good times

So you awoke during your procedure?

No

I mean after the operation

I see

Did they use a mask or a needle to put you to sleep?

needle

How long did it take?

Don't remember

I think it was pretty short

Like under 10 minutes

Is it like falling to sleep normally?

I think so?

Or like getting knocked out randomly

Except much more abrupt

Ok

Well I've never been knocked out so who knows

Tho I had some local anesthesia too and it was also fine, really

Although I had to drag my limp arm back home afterwards :p

During the same procedure or a different one

different one

Though I'll say this

Avoid local anesthesia for dental work if you can

Personally it rarely works fine

but that's me

Yeah when I went to the dentist it hurt a lot and he had to apply it more than once

@ChrisWhite Why is web stuff such a major goof

I'm just trying to make a blog

and it works locally

but remotely this thing just blows up

@ChrisWhite I'm using Jekyll (a Ruby framework) and it works beautifully on my local server

I want to set this on fire

C masterrace?

Lol

I'm a Python peasant for life

Love the language

@ChrisWhite Is this working for you?

for fucks sake

God why have you forsaken me

what is wrong with TeX

Github is playing games with me

very funny

@BernardMeurer It's Michelle

@0celo7 I sent her a text, she didn't respond

But the 1-3 days waiting time is usual, and understandable

@0celo7 While it work reasonably well for basic markup it is a gobstoppingly difficult programming language. Too many different categories of tokens. A complex and mutable scheme for figuring which class a token goes in. The available primitives are, well, primitive. And a few other things that have slipped my mind for the moment.

And have you looked at the debugging?!?

And I say that as someone who uses it (to write documents, not to program in) constantly.

@dmckee I don't even know what a token is

@0celo7 An element of syntax. A keyword, identifier, operator, grouping symbol, end-of-statement symbol and so on.

You really have to read The TeX Book to disbelieve it.

Does it work now?

I don't know. What is it suppose to do. I see a blog with a picture and some text with links.

Is it pretty, with CSS and all, or is it ugly bare HTML?

@ACuriousMind @ChrisWhite How do you feel about the notation $M_p$ for the tangent space at $p$?

@ChrisWhite e.g. Cheeger & Ebin use $M_p$

Hawking & Ellis uses $T_p$ (no $M$)

@ChrisWhite Wait, are you saying you've only seen $T_p$ or $T_pM$

Plenty of white space, too. So I think your CSS is doing something.

I just don't know if it is what you want.

@ChrisWhite Huh?

@dmckee It works, thanks :)

@ChrisWhite Yeah I tried but I really wanted some fancy FX

I can't stop it, I like prettyness

Should I bring Abramowitz and Stegun back to school with me this time?

I'll second Chris about scripts. I flatly won't use site when I have to allow too many scripts to no obvious purpose.

Am I a noob if I don't know/care about scripts

@0celo7 No, I don't care about scripts either

Maybe we're both noobs though

Script me up

@ChrisWhite @dmckee Alright, I'll see what i can strip down

I have 16GB of RAM and a decent processor