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14:07

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I wrote a program that computes the fast insert_name_here transform of a matrix. I am at a loss of what its application is, what its proper name should be, and find an existing algorithm for it. I posted this question in Computer Science, and one of their members suggested it might be better serv...

discussion

Quill

14:24

Whoever just flagged that message; don't be childish, flags aren't toys

Vogel612

cooool. a reflag for the very same message again,...

@JohnDuffield watch the language, and tell others to do so too. please.

FWIW, @Flagger replies like this are probably in jest

that said reflagging the same message over and over is flag abuse, which is punishable by extended bans

yuggib

@Vogel612 they're probably not...

(if the flagged reply was the removed one)

Vogel612

yea the flagged one is the removed one.

yuggib

sadly, it's not just in jest

Vogel612

urk :/

damnit now I can't delete my message anymore

ACuriousMind

14:32

@KyleKanos Haha...at least one ranking in which I'm ahead of you!

Vogel612

I really like how all the room owners here are mods...

eh well. flag police out

yuggib

I salute you with this song

The Pogues - The Wild Rover

►

ACuriousMind

@Slereah It means cluster decomposition doesn't make sense ;P

yuggib

that was reminded by me by the word jest

John Duffield

@Vogel612 : please tell Kyle Kanos to do the same. Follow the link back, he called me a crackpot. I'm not.

Slereah

14:34

Well yes but I assume that experiments aren't really influenced by events at infinity, either

it is probably valid under some other demonstration, I suppose

Probably by the decay of gauge fields or some shit

Vogel612

@JohnDuffield how about just flagging them then instead of stooping to that level?

ACuriousMind

Well, I never really understood what's so great about cluster decomposition, sooo...no idea

But...what has it to do with ladder operators?

Slereah

Well apparently under pretty broad conditions if the Hamiltonian is written in ladder operators

Then you get cluster decomposition

John Duffield

@Vogel612 : I've tried that before, and got warned to stop flagging, then before I did anything else I got a week-long break.

Slereah

Which makes sense since that means the field is free!

ACuriousMind

14:37

@Slereah I thought it was just that if I examine a correlation function of localized operators and then send them apart, the amplitude factors into the product of their individual expectation values.

Slereah

Pretty much, yeah

ACuriousMind

I don't really see what that has to do with ladder operators

yuggib

@Slereah that's not an immediate consequence

Slereah

$S_{a+b+c+..., \alpha + \beta + \gamma + ...} = S_{a,\alpha} S_{b,\beta}...$

if sufficiently far

Well apparently it's easy to prove if you can decompose things into ladder operators

0celo7

Weinberg does not state it like that. He chants some alien ritual

ACuriousMind

14:39

@Slereah Well...that does mean it is necessary for the theory to have ladders in oder to have decomposition

@0celo7 Well, yes, it's Weinberg :P

Slereah

Weinberg is a tad dry, yes

Although after reading some Jaffe, I have warmed up to Weinberg

ACuriousMind

Haha

Slereah

I assume it is still valid even for interacting theories, though

ACuriousMind

@Slereah I think one often quietly postulates the validity instead of checking it

Slereah

Because I don't think the next galaxy influences results that much at CERN

I guess that has to do with the inverse square law form of the forces involved, though

yuggib

14:42

@Slereah ladder operators does not mean free theories (if it's Haag theorem you are thinking about)

Vogel612

@JohnDuffield depending on who told you that you shouldn't really care whether they like the flags or not. Offensive and insulting messages should be removed. If it doesn't happen with regular flags, I think your mods should be able to clean the mess up and hand out suspensions as necessary

Slereah

If the forces were $r^2$ instead of $r^{-2}$ I guess they'd be a bit more influential!

@yuggib Yeah I am exagerating a tad

ACuriousMind

@Vogel612 Mods told him to stop flagging. This whole situation is under observation from several mods (not only ours) and has been brewing for some time.

Slereah

Once brewed it will be delicious

Vogel612

@ACuriousMind hmm. okies, I'll just keep my head out of the line of fire

thanks for the heads up

ACuriousMind

14:46

@Slereah Eccch, I prefer a cold beer everyday

yuggib

@Slereah It would taste of stubbornness, with a hint of boredom

Slereah

But revenge is a dish best served cold

0celo7

Eccch is not an English expression

user54412

^^ I always have to stop and think if that's an original Klingon saying or not.

0celo7

You some kind of foreigner ::furrows brow::

ACuriousMind

14:49

@0celo7 Well, duh, Sherlock.

Slereah

The American WoodEch

►

@ChrisWhite Well it is from the Klingon poet Shakespeare

0celo7

@ACuriousMind What, I'm not British

Jiminion

Does anyone know about the LIGO gravitational wave rumors?

Slereah

Are the aliens finally coming

Or did a truck pass close by and set off the detectors

yuggib

i.space.com/images/i/000/018/937/original/…

or

Slereah

15:00

Ayyyy

0celo7

Lmao

yuggib

?

Slereah

Can you guess which one is most likely to be related to gravitational waves

yuggib

another type of alien

ACuriousMind

@0celo7 He's asking which of the aliens might be coming :P

@Slereah Illegal immigrant stampeding past the LIGO detector, obviously.

0celo7

15:02

Where is LIGO

ACuriousMind

No idea :D

Slereah

The border

probably

Louisiana, apparently

0celo7

What if an alien ship has a nonzero quadrupole moment but they can't be detected by any other means

user54412

And Washington

user54412

so Canadians perhaps

0celo7

15:03

We need to build a wall to the north

1) keep the damn Canadians out

2) let LIGO run in peace

Slereah

Canadians eh?

ACuriousMind

Speaking of which, what happened to Jim?

0celo7

Probably got his legs taken off by a mine at the border

yuggib

abducted by aliens

user54412

@Jiminion They've been brewing for a couple months:

user54412

15:06

Nov 12 '15 at 23:19, by Chris White

3 or 4 times in the last couple weeks I've heard rumors of LIGO having found something

Slereah

are they substantial rumors, though

yuggib

today everyone brews

0celo7

Who cares? Will this raise GDP

Slereah

Or were people like "Oh nevermind I accidentally stepped on the detector"

Jiminion

LIGO is at the Hanford complex in Wash. State (former nuclear energy facility)

What would detecting grav. waves mean?

0celo7

15:10

Do grav waves raise GDP

Slereah

not much

Just confirmations of GR

0celo7

Say, @ACuriousMind, how does Mass Effect actually work

Slereah

Also maybe doing some g waves astronomy

0celo7

So we won't ever have g wave cell phones

Slereah

Do you really want to have to rotate your cellphone to have quadrupolar momentum

0celo7

15:11

Put a spinning dumb bell inside

Slereah

might be a bit awkward to use

neutrino phone would be more practical

0celo7

Signal everywhere...

Emilio Pisanty

15:25

@CuriousOne and @Qmechanic Good catch on that 35th thing.

0celo7

15:41

Do we have the new design yet

Aaron Hall

Why have I been summoned?

ACuriousMind

...you have?

Mike Miller

i got beeped about an event

ArtOfCode

and me

ACuriousMind

@MikeMiller Ah, yes, chat session is starting soon

David Z

15:49

@0celo7 no

10 minutes to the chat session

Aaron Hall

The system is never wrong, I must be needed here - but for what?

David Z

Hi everyone, chat session time! Who's here?

I always ask that but I'm not sure what the point is given that you all were just talking about being summoned :-P

Terry Bollinger

Hellooo all...

Hey, is anyone familiar with any of the (likely very small) number of papers proposing alternative color charge scenarios for quarks, e.g. mixes of color and anti-color? Glashow mentions one at least, but that was like in the 1970s!

(This is called intentionally priming the pump with a physics question...)

David Z

16:05

Cool, I approve

Terry Bollinger

David Z, hello, happy New Year!

David Z

Same to you!

Terry Bollinger

I see some new (to me) icons. How are you folks? Happy New Year to you also.

Physics Meta

0

Q: Generalizing the homework policy

In our last chat session two weeks ago (sorry for the delay), we had a discussion about updating the homework policy and homework close reason. I'm making this post to summarize that discussion and solicit feedback on how to proceed afterwards. The current status According to the homework polic...

discussion scope homework

5

David Z

Anyway, not to take away from color charge, but we do have some other things to discuss today. There is ^^that

and also the rumor of a gravitational wave detection at LIGO: theguardian.com/science/2016/jan/12/…

Terry Bollinger

16:10

I hope the rumor proves true! I still recall Webb's fascinating and fully sincere "finding" back in... jeepers, the 1970s? I still find his data baffling. Reminds me also of the infamous Valentine's Day monopole finding, also decades ago.

user54412

So I've just heard rather specific rumors (yes, more than one).

Terry Bollinger

@DavidZ I still strongly favor "lazy is bad" with instantiations in (1) don't calculate for others, and (2) chide folks, nicely, when they don't bother to do a basic Google search first.

@ChrisWhite wow, that would be fantastic if they finally nailed something!

David Z

@TerryBollinger yeah, I think you were pretty consistent with that last time

Terry Bollinger

@DavidZ I like it because there are times where homework produces really profound misunderstandings of issues, and those seem like fair game here. Lazy is... well, lazy.

user54412

The nonspecific rumors: certain key LIGO people seem rather happy, and they've been inquiring about the timeline for getting into the next decadal survey (the place where astro makes a coordinated report to Congress to petition for funding).

Terry Bollinger

16:13

Hi @0celo7!

Happy New Year!

@ChrisWhite hmm. Funding timing always bugs me. String theory always comes up with fantastic new ideas shortly before funding decisions, they have it down to an art.

user54412

The more specific: 7 NS-NS mergers. Also, one very high sigma BH-BH event with not only inspiral but also ringdown.

David Z

That's very specific indeed

user54412

Of course, if I were directing LIGO I would intentionally spread all sorts of false rumors to different sources, thus diluting the truth with noise and tracking the leaks.

David Z

I just read in the Nature News article that LIGO has a group which can fiddle with the mirrors to fake a detection :-P

user54412

Yes, and they've done this before.

Terry Bollinger

16:19

@ChrisWhite what? are you suggesting that research sometimes includes game playing?? actually, the false rumor method is also great for tracking leaks...

@ChrisWhite did you have an online source for that deep-dive specificity?

user54412

@TerryBollinger no

user54412

it's not clear whether that should increase or decrease your belief in its credibility

Terry Bollinger

Anyone: Any rumors of actual publication anytime soon? They did say "months" of rumors, so perhaps the time is getting riper?

user54412

I also heard "end of January" thrown around...

user54412

But, even if that's more than a rumor, when has a publication ever obeyed a schedule?

Terry Bollinger

16:22

(we now have two Chris's, my brain is overwhelmed easily...)

@ChrisWhite all in all it sounds encouraging... what was that about funding, though? when is that deadline?

Bass

Hi guys, in case anyone's interested, I put the ChatJax script into a greasemonkey script, so I don't have to click on "start chatjax" every time. The script starts the ChatJax stuff automatically when I'm on the chat page. If anyone wants the script too just ask.

DanielSank

@Bass Post a link and I'll star it.

David Z

@Bass That would be nice if you could post it somewhere

Terry Bollinger

@DavidZ the danger in all of this is that this is very, very delicate detection work, and so many tiny things can go wrong. I appreciate that they are trying to validate. Just look at the last couple of years for examples of what can go wrong, e.g. superluminal neutrinos.

Bass

@DanielSank @DavidZ gonna put it in a gist and post the link.

Terry Bollinger

16:26

@Bass that would be great!

Can you post it somewhere?

David Z

Yeah, I do get the sense that people are being more cautious now. I would expect that that attitude is part of the reason LIGO has this "detection drill" procedure.

user54412

@TerryBollinger So every 10 years, the Important People in astro put together a report prioritizing all the upcoming proposed projects. The next will be released in 2020, but I'm not sure when they start writing it. You really don't want to have the case for your project be made in 2021.

Terry Bollinger

@ChrisWhite 2020 is a good date, hmm, it shows up more broadly in US federal in fact. That makes me feel better about the timing, too. It's "we have this fantastic finding!" exactly one month before the committee make the funding allocation that makes me nervous for any type of research. Years, no problem.

(just remembered to activate ChatJax...)

Happy New Year @JohnRennie!

David Z

Ironically no math yet

DanielSank

@DavidZ Thanks for the meta post.

Terry Bollinger

16:31

@DavidZ I noticed, a bit rare that.

John Rennie

@TerryBollinger And to you :-) Sorry I'm late!

Terry Bollinger

@JohnRennie, any rumors from your parts about the gravity wave possible finding?

David Z

@DanielSank you're welcome... it turned out to be quite tricky to wrap up the previous chat session into a meta post, but I figured better to get something up by the time we started today than to keep putting it off

Terry Bollinger

@DavidZ I meta post in a field once, it was holding up a fence...

David Z

*groan*

DanielSank

16:33

I think you did a good job. My previous post was a yes/no question but yours encourages folks to actually draft the new policy. Good next step.

John Rennie

@TerryBollinger I would guess there's one rumour and it's spread. I've seen comments all over the web, but I bet they can all be traced back to a single source.

Terry Bollinger

(sorry, that was good work you did!)

DanielSank

@TerryBollinger oh boy...

Terry Bollinger

@DanielSank Agree!

Bass

@DanielSank GreaseMonkey script to automatically activate ChatJax: gist.github.com/bassup/93f78c0fac2a7be25086

3

David Z

16:34

@JohnRennie Lawrence Krauss says he has independent confirmation, but I don't know what to make of that

Terry Bollinger

@JohnRennie rumor pedigree tracking is an interesting art in its own right...

Bass

Please give it a try to see if it works for you.

Terry Bollinger

@DavidZ I do like that Krauss is standing firm...

David Z

My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting.

Tweeted by LKrauss1 on January 11, 2016 at 3:46 PM

Interesting, the feedback he's getting on Twitter seems quite critical

Terry Bollinger

@DavidZ cool. Krauss has a reputation to maintain. Doesn't prove anything, but it does indicate he's seen something non-trivial.

DanielSank

16:36

For anyone else who was interested (I forget who they were):

Here's that python program that does Lorentz transformations

2

0celo7

Must be a chat session

David Z

yep

0celo7

Anyone here know how to DIY dentistry

I have a painful spot on my gums by my molars and want to check it out

DanielSank

^ Bad things are about to go down.

Terry Bollinger

@0celo7 got some good pliers??

0celo7

16:39

Not operate just see what it looks like

user54412

^ Famous last words

DanielSank

@0celo7 You could say that's a cavity in my knowledge.

0celo7

No I think it's a cut

I was at the dentist's last week and got an X ray

Bernard Meurer

@0celo7 I can get you a skype dentist appointment if you wish hahahaha.

David Z

This is not something that needs to be discussed in a chat session :-/

DanielSank

16:40

@BernardMeurer Are you by chance familiar with Scala?

user54412

@DavidZ Wow, the rage is real.

David Z

Yeah, that's the internet :-P

0celo7

@DavidZ you could build me a cool mirror to look back there

DanielSank

@ChrisWhite ::Eats popcorn::

user54412

I can only hope to one day be important enough to have the internet rage at me.

Bernard Meurer

16:42

@DanielSank I've heard of it and read some of the documentation but haven't really gotten into it. Was wishin to, functional programming seems beautiful

John Rennie

@0celo7 Not sure if this link will work ...

facebook.com/…

0celo7

I does.

I've never had a cavity or anything bad

user54412

why did I click that link?

DanielSank

ewwwwwwww

0celo7

But I think I got a cut on my gums

Terry Bollinger

16:43

@0celo7 speaking of mirrors, did you know that the electrons at that reflect light from metal are at the top of the Fermi sea, and hot enough to kill you with X-rays if they suddenly fell to ground?

0celo7

What

DanielSank

@0celo7 If it's worth ten bucks, just buy a mirror.

@TerryBollinger That's pretty cool.

er, hot

0celo7

How do I use that from my perspective

John Rennie

The endoscope I used was only about $10

Terry Bollinger

@JohnRennie yep, little mirrors on sticks are cheap and available at any pharmacy.

Our talk is resonating around a cavity. We have created a resonance cavity...

0celo7

16:46

I don't have a cavity!

DanielSank

@BernardMeurer For what it's worth, Scala's not just for functional programming. It fixes other annoying stuff from Java.

John Rennie

@0celo7 I imagine you have several cavities, just none in your teeth.

Terry Bollinger

@0celo7 I speak metaphorically! Sounds like you have a cut... or a lot more ominously, possibly an infected root, sorry but it's a possibility...

0celo7

@JohnRennie Nope

ACuriousMind

@0celo7 ...how do you speak, or eat, or breathe, then?

John Rennie

16:48

@TerryBollinger Is there a screaming noise? Yes - you may have an infected root. No - you don't have an infected root.

0celo7

@ACuriousMind Dunno, how do you

Terry Bollinger

@JohnRennie that's a nice binary!

0celo7

@TerryBollinger It could be a piece of popcorn exacting its revenge

ACuriousMind

@DavidZ: Feature the HW policy post, maybe? We want as much input on this as possible, right?

DanielSank

@JohnRennie Ever heard of a resorption? I had that. Zero pain. So weird.

David Z

16:49

Ah yeah, good idea

John Rennie

@0celo7 You don't have one of these then:

medical-dictionary.thefreedictionary.com/buccal+cavity

0celo7

Is getting your wisdom teeth out terrible

@JohnRennie no

Terry Bollinger

@ACuriousMind if it's kind of itchy-annoying, yep. A rubber pointy poker jobber can help.

DanielSank

@0celo7 meh

Terry Bollinger

@0celo7 depends. Oral surgery: yes. Regular extraction: no. Popcorn: Don't do anything drastic!

0celo7

16:51

Regular extraction?

I need my bottom two out and the doc recommended I get my top two taken out as well.

DanielSank

^ Separate chat room?

0celo7

@DanielSank uh, biophysics

DanielSank

lol

John Rennie

@0celo7 Or any of these?

Body cavity search

A body cavity search is either a visual search or a manual internal inspection of body cavities for prohibited materials (contraband), such as illegal drugs, money, jewelry, or weapons. Body cavities used for concealment include nostrils, ears, mouth, navel, penis (urethra and foreskin) or vagina, and rectum. It is far more invasive than the standard strip search that is typically performed on individuals taken into custody, either upon police arrest or incarceration at a jail, prison, or psychiatric hospital. Often the procedure is repeated when the person leaves the institution. Body cavi...

0celo7

Never had one of those either

David Z

16:54

@DanielSank if people were interested in talking about the replacement-homework-policy or gravitational waves, I would enforce that. But apparently not :-P

DanielSank

Ok, uh... I think we should rename the homework policy and modify the tag and close reason. Also we should modify our behavior.

John Rennie

@DavidZ The trouble is that the homework question is hard to chat about.

David Z

@DanielSank lol

John Rennie

I really want to sit down and write an answer to your question to help get my view straight.

David Z

@JohnRennie yeah, that's okay

DanielSank

16:56

Most of what I think is explained here.

John Rennie

There's the obvious aspect of not helping people cheat, and that stays the same.

DanielSank

So I'll focus on a related sub-issue here in this chat.

John Rennie

But apart from this I think my main concern is I don't want to be taken advantage of.

David Z

@JohnRennie ooh, right. Actually I forgot to include a section in the question about what our goals should be with the new policy, specifically those that carry over from the current policy.

Terry Bollinger

@0celo7 btw, I really liked your carbon nanotubes reponse!

John Rennie

16:57

If a beginner asks a simple question and I believe they really want to know then I'd probably answer

DanielSank

I think there's a lot of "off-topic" voting that goes on here because folks don't want to say that a question is too broad, or unclear.

David Z

@JohnRennie I think I know what you mean, but to be clear: in what sense don't you want to be taken advantage of?

Bernard Meurer

@DanielSank I was aware that it fixed a lot of things people hate about java, in addition to being functional. Why do you ask though? You think it could be an interest thing to learn?

0celo7

We were having such a nice discussion about teeth...

@TerryBollinger o.0 link

I know nothing about carbon nanotubes

DanielSank

@BernardMeurer I'm learning it. I like it. There are a few things I don't understand so I was checking the possibility for discussion on those things.

John Rennie

16:58

@DavidZ if someone is genuinely interested and don't know how a calculation is done then I'd probably be willing to show them

Terry Bollinger

@0celo7 it had some bite, didn't it? something to chew on?

0celo7

Wtf are you talking about

David Z

@DanielSank could be, although I wonder about the motivation for that. Why would people be reluctant to say that a question is too broad or unclear?

(I do know those close reasons themselves are not especially clear)

Bernard Meurer

@DanielSank I'll certainly pick it up then, I've been wanting to learn something functional for a while, and Lisp is giving me shivers.

John Rennie

@DavidZ If I think someone could work ouit the answer but they consider it easier to ask me then I probably wouldn't answer

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