The h Bar

Emilio Pisanty

4:00 PM

@DanielSank yeah, that's the core bit of the argument.

DanielSank

Plz add that to answer.

Or I can.

Wait a sec, we're in the middle of a scheduled chat session... talking about physics?

What has this site come to?

enumaris

hmmm

DoublyNegative

What're the normal discussion topics? (He says, before returning to lurk! :P)

enumaris

The perfect temperature to cook a steak to

DanielSank

...and other food related topics.

DoublyNegative

4:04 PM

Fair enough!

John Rennie

Mobile phones?

Why Windows/OSX/Linux (delete as appropriate) suck?

DoublyNegative

Ngl, slightly triggered at the way this chat thing cuts of the last letter of my name. Not enough of the name to make it clear that it's been cut off, just enough to make it look exactly as though I can't spell 'Negative'.

enumaris

I see the full name

DoublyNegative

Ah, so in that respect, something akin to your average internet chatroom - the never-ending argument over technology!

Ah well, just my Chrome deciding to wind me up, then! :P

Anonymous

@DoublyNegative That's probably the screen size messing up.

Emilio Pisanty

4:06 PM

@DanielSank done.

John Rennie

DanielSank

@JohnRennie But obviously BSD is better than all of those...

John Rennie

@DoublyNegative It sometimes shows your full name and sometimes doesn't.

(on Chrome 69)

Anonymous

It shows the full name for longer messages

DoublyNegative

Evidently! :P I mean, it makes logical sense that it would simply scale it for different screen sizes: just didn't on my screen because why not! :P

DanielSank

4:09 PM

@JohnRennie Sometimes it does and sometimes it doesn't. You can't explain that!

Emilio Pisanty

@DanielSank Here's the million-dollar question, though: in $$\sum_n \frac{⟨f|\mathcal{O}|n⟩ ⟨n|\mathcal{O}|i⟩}{\omega_i-\omega_n+\omega_p},$$ why do some terms contribute with a positive sign and some terms with a negative sign?

DanielSank

@EmilioPisanty Because reasons.

Emilio Pisanty

@DanielSank =P

DanielSank

Perhaps you prefer "Because quantum mechanics".

Emilio Pisanty

it's one of the greatest answers ever given by my PhD supervisor

"because resonance"

DanielSank

4:10 PM

Actually though, there is a good reason.

Emilio Pisanty

specifically, because oscillators driven below resonance are in phase with the driver, and oscillators driven above resonance are $\pi$ out of phase.

DanielSank

It's probably the same reason that the phase shift of a driven oscillator relative to the drive frequency flips over as the drive frequency crosses through resonance.

Jinx

Emilio Pisanty

@DanielSank well, you got it on your own

DanielSank

Well sh--. Can I have a professor position now?

Nick

@DanielSank only if you prove double spring pendulums work better in space.

John Rennie

4:11 PM

@DoublyNegative aaah, I think it truncates the name if there isn't room to put the name under the icon. So if you type a three line message, or three lines of sequantial messages, then it will show you name in full.

Emilio Pisanty

@DanielSank I can try and reconstruct my supervisor's CV as it looked like when he first got a professor position

I suspect you won't like it

DanielSank

@EmilioPisanty ?

@Nick Do I do something else?

DoublyNegative

That makes sense, I suppose, from a site design perspective. Thanks, John! :D

John Rennie

Here's a one line message

Emilio Pisanty

@DanielSank it includes things like this: scholar.google.co.uk/…

John Rennie

4:12 PM

Here's
a
three line message

DanielSank

@JohnRennie I see your full name in both cases.

@EmilioPisanty Looks legit.

Nick

@DanielSank Dig a hole to china but instead find oil to sell the arabs... idk, just do something. Maybe a funny dance. I'm sure you could get a few PhDs that way as well.

John Rennie

Nick

@JohnRennie here's just one.

Emilio Pisanty

@DanielSank oh, it's legit. It's just not the kind of paper that you stumble onto in the shower.

enumaris

4:14 PM

Fun beans

Nick

next, my most amazing message yet. It's called 'none'

DanielSank

@EmilioPisanty Not sure I've ever stumbled on a paper in the shower...

Anonymous

@JohnRennie Press Ctrl + "+" and start zooming in. When you get to around 150% it shows only "John" in the first case ;)

John Rennie

@DanielSank yes, because my name is short enough to fit on the left of the icon.

DanielSank

@Blue Jeez. I saw that message and read it as "C++" and almost had a panic attack.

Emilio Pisanty

4:14 PM

@DanielSank the idea for. you know what I mean.

that paper basically re-defined the whole field.

DanielSank

@EmilioPisanty ah

orly?

Anonymous

That is, if your name has a space in between, it will try to truncate smartly. But "DoublyNegative" doesn't have any space

Emilio Pisanty

@DanielSank what?

John Rennie

DanielSank

@EmilioPisanty Redefined the field. Neat.

John Rennie

4:15 PM

@Blue aha, yes!

DanielSank

Hey @EmilioPisanty, ever since you changed your avatar, I don't trust it's really you. Send me some tunes to verify your identity.

enumaris

I would like to down-star the message with a missing parenthesis on the right

let it be known that this is an official request

DanielSank

@enumaris I have often wished for down-star ability.

For grammar reasons...

enumaris

I also wish for it

Emilio Pisanty

@DanielSank don't mention this place. I had to ride on a cramped Paris metro for an extra hour yesterday due to a poor choice of outbound airport.

@DanielSank so... shiny-figure-from-latest-paper doesn't sell it?

DanielSank

4:17 PM

Heh

@EmilioPisanty Latest paper link plz.

Emilio Pisanty

@DanielSank arxiv.org/abs/1808.05193

enumaris

COBOL engineering has arrived

time to run away

DanielSank

@enumaris Where?!

@EmilioPisanty Oooooh: "...which we experimentally observe..."

Nice

enumaris

@DanielSank points at ACM

Emilio Pisanty

@DanielSank ;-)

check out figs. 3 c-f and S4

they're basically raw experimental data

ACuriousMind

4:19 PM

@enumaris Hmmmmmm?

Anonymous

@DanielSank Why don't you put a space between "Daniel" and "Sank"? Now that I've noticed it, I can't unsee it.....and that disturbs me :P

Emilio Pisanty

(which I helped analyze and contextualize only. I did not touch any of the hardware, for the good of the project.)

DanielSank

S5 is where it's at.

@Blue Because it's a username and usernames shall contain no spaces!!!

Emilio Pisanty

@DanielSank there's a lot to be said for S5.

I do wonder whether people will actually print them out

I have no way of tracking that, though

DanielSank

@Blue Realistically, because I grew up in the days where file names and user names etc. couldn't have spaces.

enumaris

4:21 PM

@ACuriousMind I'm gonna call you COBOL engineering from now on :D

DanielSank

@EmilioPisanty That's unfortunate.

Howdy, @ACuriousMind.

Emilio Pisanty

@DanielSank though it does have a download count

ACuriousMind

Hello, Dr @DanielSank

Emilio Pisanty

24 views and 11 downloads isn't bad at all, actually

particularly since a reasonable fraction of the views is probably me

Anonymous

@DanielSank I feel......lucky ;)

DanielSank

4:23 PM

I still get the heebie jeebies when people use spaces in file names.

That used to lead to some amount of pain.

Unix usernames are still no-spaces.

Does Windows allow spaces in usernames, @JohnRennie?

John Rennie

@DanielSank I agree with you about usernames. I believe Windows now allows usernames with spaces, but it still feels wrong. I have used a language (Algol 68) that allowed spaces in variable names, and that really took some getting used to.

ACuriousMind

@Blue Pragmatically, you can't put spaces in usernames because there's no logic to determine whether @Daniel Sank is supposed to be a ping of the user "Daniel Sank" or the message "Sank" directed at the user "Daniel"

DanielSank

@JohnRennie Eesh. How does such a language parse anything?

enumaris

by being very careful

lol

John Rennie

@DanielSank the language syntax is so precisely defined that there is never any ambiguity.

Emilio Pisanty

4:25 PM

@ACuriousMind that's... not how pings work.

Anonymous

@ACuriousMind Duh, just give an option to auto-convert it to @'Daniel Sank' . Even without the "auto" thing it'd work actually

DanielSank

@ACuriousMind Right, otherwise you'd need e.g. @(Daniel Sank) or similar.

John Rennie

Algol 68 was in many ways a lovely language, but it never graduated from being a research language to the real world of programming.

DanielSank

@Blue Or, duh, don't try to support it at all, which is often the best choice.

John Rennie

I think we need to distinguish between the username and the display name. The name with a space in is just a display name.

Emilio Pisanty

4:26 PM

John Rennie

I have no problem with display names containing spaces

enumaris

NO SPACES

Emilio Pisanty

@DanielSank if you do print them out, pls let me know =).

ACuriousMind

Parsing Algol must be almost as terrible as parsing ABAP :P

John Rennie

@ACuriousMind Algol 68. There were several versions of Algol of which the most popular (Algol 60 I think) was a much less structured language than Algol 68.

In fact it's very easy to parse because the syntax is so rigidly defined.

Emilio Pisanty

4:29 PM

@JohnRennie wait, there's languages-with-year-numbers where the year is 1960?

John Rennie

Algol 68 was developed at around the same time as C, which is a real dogs breakfast of a language, and which became more popular ... ?

Emilio Pisanty

I thought y'all were still using slide rules back then

ACuriousMind

@DanielSank Windows also allows non-ASCII symbols in usernames, notably umlauts. On one of my Windows machines I used my name with the proper umlauts as username. I ended up with about ten different "Users" directories because many applications mangled the umlauts into random garbage and created new directories with their own, mangled username. Lesson: Don't use everything Windows allows because a lot of non-Microsoft applications also need to handle your username

enumaris

The oldest programming language I've had to really work with was probably Fortran 77

It was annoying :D

John Rennie

ALGOL

ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages, originally developed in the mid-1950s, which greatly influenced many other languages and was the standard method for algorithm description used by the ACM in textbooks and academic sources for more than thirty years.In the sense that the syntax of most modern languages is "Algol-like", it was arguably the most influential of the four high-level programming languages among which it was roughly contemporary: FORTRAN, Lisp, and COBOL. It was designed to avoid some of the perceived problems with FORTRAN...

ACuriousMind

4:31 PM

@JohnRennie Ease of parsing and rigidity of the syntax are not directly correlated

Emilio Pisanty

speaking of which

enumaris

@ACuriousMind Can you provide a nice graph showing that?

Emilio Pisanty

this came in the mail this morning

enumaris

@ACuriousMind and, why are you in the wikipedia article on ALGOL?

"...was the standard method for algorithm description used by the ACM in textbooks..."

ACuriousMind

@EmilioPisanty Ah, are you preparing for a time travel and don't want to give away your game with a calculator?

Emilio Pisanty

4:35 PM

@ACuriousMind I was just curious about how these things work

John Rennie

When I was at school we still had to use slide rules in exams.

That was early to mid 70s, before electronic calculators became affordable.

My first calculator:

Sinclair Scientific

The Sinclair Scientific calculator was a 12-function, pocket-sized scientific calculator introduced in 1974, dramatically undercutting in price other calculators available at the time. The Sinclair Scientific Programmable, released a year later, was advertised as the first budget programmable calculator. Significant modifications to the algorithms used meant that a chipset intended for a four-function calculator was able to process scientific functions, but at the cost of reduced speed and accuracy. Compared to contemporary scientific calculators, some functions were slow to execute, and others...

ACuriousMind

@enumaris no one shall ever know

enumaris

"shall"

sounds pretty forceful bro

DanielSank

@EmilioPisanty i don't haz printer.

@ACuriousMind ugh

John Rennie

I think we have an HNQ candidate here. Five answers in an hour.

Emilio Pisanty

4:40 PM

@JohnRennie not a lot of votes, though

this one was in much the same situation and it didn't make the cut.

John Rennie

While I have the QM big guns here: if I Compton scatter a photon with a well known initial momentum off an electron, is the scattering angle randomly distributed?

Emilio Pisanty

@JohnRennie you mean this thread?

which btw @ACuriousMind could use some mod attention. see my flag.

ACuriousMind

@EmilioPisanty Already working through the flag queue :P

John Rennie

@EmilioPisanty I was thinking of that, though the OP is sufficiently confused that I'm not sure they know what they are asking.

Emilio Pisanty

@JohnRennie I mean, 'cause I ain't touching that one with a ten-foot pole if I can help it

@JohnRennie I assume the electron also has a well-defined momentum?

John Rennie

4:44 PM

But my question is more specific. If we scatter a photon off a stationary electron then the scattering angle and energy shift are correlated, but are they random i.e. if I repeat the exact same expt many times do I get a distribution of scattering angles?

I'm pretty certain the answer is yes but not 100% certain.

enumaris

Classically, would depend on impact parameter right

Emilio Pisanty

@JohnRennie yes

enumaris

so, randomized to the level that the impact parameter is randomized :D

QM wise, I'm sure it's always randomized cus of HUP

John Rennie

@EmilioPisanty so after scattering the photon and electron are ina superposition of all possible scattering angles (and therefore energy shifts)?

Emilio Pisanty

@JohnRennie yes

Semiclassical

4:46 PM

Randomized with what distribution, is the question

Emilio Pisanty

moreover, the photon and the electron are entangled.

enumaris

@Semiclassical when in doubt, choose Gaussian

Semiclassical

on the real line, sure

enumaris

if someone disputes you, just say you are repeating the experiment an infinite number of times and that's what you meant

Emilio Pisanty

@enumaris not particularly gaussian, no.

cf. above.

John Rennie

4:47 PM

@EmilioPisanty thanks, I was fairly certain that was the case but didn't want to say anything without being absolutely sure. Maybe I will attempt to post a sensible answer to Artur's question then.

Semiclassical

As a distribution on scattering angles, Gaussian doesn’t work so well

John Rennie

Or maybe not ...

enumaris

covers ears and shouts CLT

Emilio Pisanty

@JohnRennie that seems extremely ill-advised to me.

Semiclassical

If only because scattering angles aren’t distributed over all real values

Emilio Pisanty

4:48 PM

but to each his own.

@Semiclassical that.

you can try something like $f(x) = N \sum_n e^{-(x-2\pi n)^2/\sigma^2}$ if you really really really want to

but

Semiclassical

One guess would be the uniform distribution on angles, but that seems too naive

Emilio Pisanty

it will be a world of pain.

unless you really know your Jacobi theta functions

Semiclassical

Lol

Emilio Pisanty

in which case, you've already paid your world-of-pain dues, so go right ahead

$N(\sigma)$ is a fun function, though.

(assuming you normalize to unity)

John Rennie

@EmilioPisanty I have an (almost) complete optimism that I can improve anyone's grasp of physics. This might be a challenge though.

ACuriousMind

4:53 PM

@JohnRennie The proper description of the distribution of the outcomes of Compton scattering is the Klein-Nishina formula

John Rennie

@ACuriousMind wow 1928. The Dirac equation can't have been around long by then, let alone QED.

enumaris

fun beans

ACuriousMind

It was one of the first triumphs of QED, yes

Emilio Pisanty

@JohnRennie yeah, a bunch of things came in fast.

Semiclassical

@ACuriousMind which goes to the uniform distribution in the low-energy limit, nice

With the leading-order correction being to lower the probability to back-scatter, because of...reasons

Emilio Pisanty

4:59 PM

Can the center of electric charge, and color charge differ in a quark? — Anders Gustafson 3 mins ago

man, good question

no idea

is there a center of color charge in SU(3)?

Semiclassical

Hmm, why is it that electrons prefer not to back-scatter as the energy goes up

ACuriousMind

@EmilioPisanty There are form factors that appear in QCD processes much like form factors related to "center of charge" in QED processes. However I don't believe that you can usefully talk about a "center of color charge" because there's no useful classical limit of chromodynamics.

Emilio Pisanty

hmmmmm.

good point.

do you strictly need a good classical limit for "center of charge" to make sense?

enumaris

the dynamics of color

how fun

Emilio Pisanty

though I guess you can't even describe quarks in non-QFT-QM the same way you can with an electron

Zirc

5:10 PM

Hi, I'm just curious, but is there a pun in the title of this group? "The h Bar"?

Anonymous

@Zirc yes...

Zirc

is it the reduced planck's constant?

Anonymous

mhm

John Rennie

@Zirc no, this room is the reduced plank constant

The plank constant is three, as in thick as three short planks. We are only as thick as two short planks.

Emilio Pisanty

@Zirc It is. It is a very original pun, too.

Zirc

5:16 PM

oh okay, cool

Emilio Pisanty

5:34 PM

"it does not have a probabilitiy to "be at a particular point", can we say that probability, of photon being in any points, at any time are the same and equals zero? — Artur 6 mins ago

@ACuriousMind A contender for the comment that makes the least sense this week?

ACuriousMind

@EmilioPisanty Just a confused user & some language issues, I don't think that's worthy of scorn. You should see some of the stuff I delete :P

Anonymous

@EmilioPisanty Umm, I guess the concept of "probability of finding X at a particular point is zero but non-zero in a region" can be a bit confusing for beginners

Emilio Pisanty

@Blue that's not what that's about, though.

@ACuriousMind yeah, I know. But it still makes no sense.

@ACuriousMind maybe "It is not nonzero" would be better?

ACuriousMind

@Blue That's not the point. The photon doesn't have a probability to be at a point, nor in a region. It just has a probability to cross a surface.

Quantum relativistic reasoning about position is annoying

Emilio Pisanty

@ACuriousMind not if you listen to anna.

you just do Riemann-Silberstein and you're done.

right?

Anonymous

5:42 PM

@ACuriousMind I see. I didn't know that. Maybe you could add that exact sentence to your answer? Would make it much more clear

Emilio Pisanty

@Blue It's already discussed in that answer.

coniferous_smellerULPBG-W8ZgjR

can someone help me with English? I wrote an answer but the person doesn't understand what I mean by "requires two materials to manifest itself" when I am talking about the Peltier effect

to me it looks crystal clear, but to the native English speaker, it doesn't at all

I want to say that the Peltier effect requires two dissimilar materials to appear

Anonymous

@coniferous_smellerULPBG-W8ZgjR Replacing "manifest itself" with "occur" should be good enough I guess

coniferous_smellerULPBG-W8ZgjR

thanks for the tip @Blue

btw @Blue is it common to speak English in India?

coz someone told me Indian actually speak English, which I didn't know. I thought it was Hindi and English only as 2nd language

but the guy told me English 1st

Anonymous

@coniferous_smellerULPBG-W8ZgjR Hinglish is quite common. Fluency is not that common though.

coniferous_smellerULPBG-W8ZgjR

5:55 PM

so roughly what I thought then? Basically Hindi or some local language 1st and then English

Anonymous

@coniferous_smellerULPBG-W8ZgjR Yup

coniferous_smellerULPBG-W8ZgjR

thanks a lot

coniferous_smellerULPBG-W8ZgjR

6:06 PM

it is possible to see the statistics of a person such as total number of votes, upvotes and downvotes on questions and answers, but is it possible to get the stat of the number of votes people gave to that person

Anonymous

@coniferous_smellerULPBG-W8ZgjR You can deduce it from the Reputation tab

coniferous_smellerULPBG-W8ZgjR

but I need to take account bounties and stuff

Anonymous

If you notice a sudden -50/-100/... that's a bounty.

coniferous_smellerULPBG-W8ZgjR

oh right on that graph I see.... would take too long to analyze ana v's history

Anonymous

It also displays "Bounty" in that case

Anonymous

6:10 PM

@coniferous_smellerULPBG-W8ZgjR Not the graph. It's listed! Just sort by "time"

Anonymous

Why are you stalking anna v tho? XD

coniferous_smellerULPBG-W8ZgjR

not particularly on her but just curious coz I see many wrong answers from her that get massively upvoted but then sometimes some people like Emilio Pisanty notice it and downvote. I want the ratio of upvotes/downvotes and compare it with John Duffield, Arpad Szendrei and Hogler something

Anonymous

Yeah, anna v's answers are sorta weird

Emilio Pisanty

@coniferous_smellerULPBG-W8ZgjR you can look it up on the data explorer

coniferous_smellerULPBG-W8ZgjR

apparently she links to the paper about the wavefunction of photons as if it was mainstream but Emilio once said it wasn't a concensus or osmething like that

she basically spams this same link over tens of answers

Emilio Pisanty

6:16 PM

data.stackexchange.com/physics/query/393837/…

I haven't looked her up, but I would expect her answer-score distribution to look absolutely nothing like Duffield's

coniferous_smellerULPBG-W8ZgjR

right thanks a lot

but nothing like Rennie either ^^

I guess

Emilio Pisanty

@coniferous_smellerULPBG-W8ZgjR I think that's an extremely unfair characterization

Anna is an extremely valuable contributor in my books.

She just... learned QM in a different time.

coniferous_smellerULPBG-W8ZgjR

I see

Emilio Pisanty

For context, she's a retired particle physicist.

coniferous_smellerULPBG-W8ZgjR

yeah I know this

Anonymous

6:20 PM

@EmilioPisanty What's her full name? (in case you know)

Emilio Pisanty

I do often disagree with her, and overwhelmingly the cause is that she's posting along attitudes that were common in the seventies and which have since been paradigm-shifted, or simply that she's not aware of more recent developments.

@Blue I don't.

Anonymous

motls.blogspot.com/2012/04/…

Anonymous

> I started in experimental elementary particle physics back in 1965, where we were building a prototype spark chamber for cosmic rays using a magnetic field .

coniferous_smellerULPBG-W8ZgjR

unable to make your script work @EmilioPisanty

I enter the ID but no matter what I get Invalid column name 'Blue'. for example

Emilio Pisanty

@coniferous_smellerULPBG-W8ZgjR use the numeric id

Anna is 1492

John is 1325

data.stackexchange.com/physics/query/393837/… anna

Anonymous

6:29 PM

1 doesn't exist

coniferous_smellerULPBG-W8ZgjR

oh

Emilio Pisanty

data.stackexchange.com/physics/query/393837/… john

Anonymous

2 is the oldest member on the site then :D

coniferous_smellerULPBG-W8ZgjR

wait Emilio so this returns a histogram of her points per question, with a log y axis?

Emilio Pisanty

@coniferous_smellerULPBG-W8ZgjR basically

@coniferous_smellerULPBG-W8ZgjR as you can see, they're basically the same.

coniferous_smellerULPBG-W8ZgjR

6:33 PM

not exactly what I was looking for but hanks anyway. so I could basically create a script

Emilio Pisanty

The full posts and votes DB is open to public SQL queries

Or you can download the data dump and analyse it locally

(modulo some caveats, obviously)

coniferous_smellerULPBG-W8ZgjR

damn my stats suck

2 votes on my last 13 answers

vzn

lol did someone say paradigm shift? :P

coniferous_smellerULPBG-W8ZgjR

do you all guys understand godel incompleteness theorem

bolbteppa

7:09 PM

What attitude did people have in the 70's?

(Just got an insane book full of crazy papers from the 70's :p)

Secret

in Mathematics, 14 mins ago, by Secret

Behold the liouville numbers (well some of them) along with the rationals

zooming in and plotting at higher iteration

We can easily see how comeage it is as they all cluster near rationals

Each blue line you saw will become 10 lines for each level of zoom of $10^{n!}$

This goes countable levels deep thus each blue line is uncountably many lines

Another nice view showing their close association to the rationals. Magnification at least 2000x

danielunderwood

@ACuriousMind The answer is that it pings me?

Secret

Stay tuned as more irrational types were being plotted

whatever you cared or not

danielunderwood

Or you have magical mod powers and it pinged all Daniel* accounts

bolbteppa

@vzn "One of the main requirements imposed on quantum field theory is invariance of the theory to the Poincare group. However, only a fraction of the interactions satisfying this requirement is realized in nature. It is possible that these interactions, unlike others, have a higher degree of symmetry. It is therefore of interest to study different algebras and groups, the invariance with respect to which imposes limitations on the form of the elementary particle interaction" thoughts?

Emilio Pisanty

7:18 PM

Having said all of which

@coniferous_smellerULPBG-W8ZgjR "not a consensus" was a bit of a euphemism

3

A: Wave function of a photon?

There is no position operator for photons, so photons do not have a spatial probability density. Associated with a photon (in a laser beam, say) one has only a probability density of hitting any given surface crossing the beam at a particular point of the surface. See Chapter B2: Photons and Ele...

bolbteppa

No (position-space) wave function for the photon is an insanely interesting issue

ACuriousMind

@danielunderwood lol, sorry

Emilio Pisanty

See e.g. that answer for just how set the consensus is against the claims in Anna's answer

Handily dug up by ACM

danielunderwood

@ACuriousMind No worries. I saw that you mentioned me on my phone and wondered what it could possibly be lol

Is that one of your mod powers?

Anonymous

@danielunderwood I think @Daniel pings you because your name starts with that string

Anonymous

7:22 PM

@Daniel

danielunderwood

I feel like there must be restrictions on that or it could be abused

Either that or I'm the Daniel of SE

Anonymous

It has something to do with 1) The users who were active in the past 2 days and their name begins with the same string 2) User activity (?)

Anonymous

If there's Daniel1 and Daniel2 who are both active, then I don't know whom it will ping

danielunderwood

I mean I understand that it pings me because my name starts with Daniel...but say if I ping a...

The better question: am I the only person it pings? I guess it didn't ping Daniel Sank?

Anonymous

@danielunderwood Even Daniel Sank's username beings with Daniel. I'm trying to understand why that pinged you and not him

Anonymous

7:27 PM

@danielunderwood That's the real question

Anonymous

14

A: What are the rules for when chat messages appear in a user's inbox?

To use you as an example: @TonyMeyer, i.e. an exact match will cause a notification if you've been in the room in the past seven days. @Tony, i.e. a first name match (to be precise, a word boundary match) will cause a notification if you've been in the room in the past two days. @Ton will notif...

Novalium Company

Pff, my IQ is 130 and I still can't do the Dual-3-back game. Whyyy... Should I try to master the Dual-2-back and then move on the dual-3-back?

Sir Cumference

Howdy

danielunderwood

@Blue But both Daniel Sank and I should be a first name match, no?

Anonymous

@danielunderwood They must be using some distance measure between strings

Anonymous

7:33 PM

According to that, yours was the better match

danielunderwood

Yeah must be. Still kind of odd to me though

Anonymous

Either that, or it sorts based on activity

Anonymous

But it doesn't ping multiple users. At least we're sure of that

Novalium Company

@Blue youtube.com/watch?v=68ugkg9RePc

Anonymous

@NovaliumCompany lol

Captain Bohemian

7:50 PM

the same theme AdS-CFT correspondence can cover a diversity of topics; some look interesting probably due to my knowledge of the material therein while some look not that interesting maybe due of my lack of knowledge of material therein.

It's like I usually feel employing AdS-CFT correspondence to extract the information of the gravity more interesting than using it for the information of quntum field theory because I know better of the former.

vzn

8:17 PM

@bolbteppa not an expert on symmetry or group principles in physics but agree they must be deep. just ask Garrett Lisi :P

Captain Bohemian

I find the application of symmetry or group principles in physics particularly interesting though I may not know the material which only appears in group theory for mathematicians.

vzn

8:45 PM

@bolbteppa btw what ref is that?

rob

@Blue I think that's comments on the main site. Ambiguous chat pings do notify multiple users. Now that another Rob is a SO moderator, something like a third of my chat pings are replies to his messages.

Anonymous

@rob Umm, does he get those notifications too?

bolbteppa

@vzn fayllar.org/what-are-these-lectures-about.html ^

rob

@Blue I believe so. There was a discussion about it when he was elected.

Anonymous

@rob Then that's really a bug :P

ACuriousMind

8:57 PM

@Blue I'm not convinced there's a way around this: Pings that are not direct replies work by username, and usernames are not unique. How are such pings supposed not to ping multiple users if they share a name?

rob

@Blue No, I don't think so. There are restrictions on who is pingable in chat --- you have to have been in the room "recently."

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