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vzn
vzn
12:04 AM
hi all just found this googling. anyone used it? looks very interesting. looking for doc/ papers that use it etc
in toy models of QM, 5 mins ago, by vzn
qutip QuTiP : Quantum Toolbox in Python
 
T Abraham
T Abraham
@alarge u seem very stubborn not to join my chatroom, huh?
 
usukidoll
usukidoll
rawr
 
T Abraham
T Abraham
@usukidoll ???
 
usukidoll
usukidoll
hi
 
T Abraham
T Abraham
@usukidoll what was that roar for?
 
usukidoll
usukidoll
12:16 AM
nothing
meow
 
T Abraham
T Abraham
@usukidoll hiss...
 
dmckee
dmckee
@TAbraham I'm not sure how to say this, but the odds are that alarge doesn't want to join your chat room at least in part because you keep pinging him in chat when he has already said he's busy with something else. Seriously.
7
People come and go in chat. They are not always available. You have to live with that.
 
T Abraham
T Abraham
@usukidoll this room isn't for cats (unless its Schrodinger's cat, lol!)
@dmckee lol..
 
usukidoll
usukidoll
don't be mean I'm sick in real life
 
T Abraham
T Abraham
@usukidoll u calling me ?
 
usukidoll
usukidoll
12:29 AM
ya
 
dmckee
dmckee
It's a week for being sick around here too. Six professor's in my building canceled classes today.
 
usukidoll
usukidoll
wow
 
T Abraham
T Abraham
@usukidoll it was a joke...plus this room is for physics, not animal noises...
 
usukidoll
usukidoll
and supposedly this year's flu shot sucks
 
T Abraham
T Abraham
@usukidoll that's offensive..
 
usukidoll
usukidoll
12:30 AM
so I took mathematical physics last semester...pdes.
 
dmckee
dmckee
The building houses three departments--about 35 profs.
 
usukidoll
usukidoll
stop picking a fight with a math major fool
 
dmckee
dmckee
So that's nearly 20%.
 
usukidoll
usukidoll
flu season is crazy
 
T Abraham
T Abraham
@usukidoll u talking to me...
 
usukidoll
usukidoll
12:31 AM
omg
YEAH WHY!
 
T Abraham
T Abraham
@usukidoll calm down..
 
usukidoll
usukidoll
>:O
 
T Abraham
T Abraham
@usukidoll bye. I don't want to talk to an angry "math major fool"...
 
usukidoll
usukidoll
-.-
go play minecraft ^^
 
T Abraham
T Abraham
@dmckee usukidoll is getting offensive.. as the mod, I hope u can do something about it...
 
usukidoll
usukidoll
12:35 AM
?
 
dmckee
dmckee
If I do something about it, it will be done to two people.
Now would be a good time to decide that the internet doesn't need "winning".
 
T Abraham
T Abraham
@dmckee ?
 
usukidoll
usukidoll
eeyup eats m&ms
 
Richard
Richard
What's all this hullaballoo? We'll have no trouble here.
 
usukidoll
usukidoll
nothing just .... nothing
 
J. Musser
J. Musser
12:38 AM
All the flagging!
Stappit
 
Richard
Richard
So much flagging.
 
3ventic
3ventic
watches as 10k users pass by
 
user61230
I joined this room two minutes ago and I'm already the second from the last person in the list.
 
Richard
Richard
Shouldn't you all be talking about physics and whatnot instead of abusing each other?
 
J. Musser
J. Musser
abuses Richard
 
T Abraham
T Abraham
12:39 AM
@Richard which is what I am trying to say..
 
Sabre Tooth
Sabre Tooth
I got the flag too? and I am not a mod nor room owner? how?
 
J. Musser
J. Musser
runs and hides
 
user61230
As a moderator, I'm going to have to ask you to stop that abusive behavior, @J.Musser.
 
J. Musser
J. Musser
@SabreTooth Because you've got over 10k combined rep
2
 
Sabre Tooth
Sabre Tooth
aaaaah
 
J. Musser
J. Musser
12:40 AM
@Emrakul :)
 
Richard
Richard
@J.Musser - Flags pop up for power users. They're pretty rare which is why we've all piled in to see what's happening
 
dmckee
dmckee
As with the sites, we rely on high rep users to do the heavy lifting on the moderation.
 
Sabre Tooth
Sabre Tooth
this is fun
when do I do the maniacal power mad laughter?
 
J. Musser
J. Musser
Those flags were mostly invalid anyways...
 
Richard
Richard
@SabreTooth - It's like taking a little holiday in someone else's villa
 
user61230
12:41 AM
@J.Musser :P
 
dmckee
dmckee
And I'd like to call your attention to a comment I posted a couple of days ago to the effect that almost all our users and no trouble and how wonderful you all are...
 
J. Musser
J. Musser
Which wouldn't count me... hibernates
 
T Abraham
T Abraham
what's happening?
 
user61230
Nice room ya got here. Would be a shame if somethin' were ta happen t'it, eh, @dmckee?
 
Sabre Tooth
Sabre Tooth
so, where is the beer?
 
T Abraham
T Abraham
12:43 AM
@SabreTooth u think being a mod is fun?
 
dmckee
dmckee
@Emrakul But I'm sure you'd be willing to sell me a ... insurance policy, eh?
 
Danu
Danu
Yoyoyo
 
T Abraham
T Abraham
@Danu hello danu..
 
user61230
@dmckee Mm. Ya got that one right.
 
Richard
Richard
Peace out, Physics dudes.
 
Sabre Tooth
Sabre Tooth
12:43 AM
@TAbraham wouldn't know
 
Danu
Danu
Peace in
 
user61230
Peace everywhere. Really, can't we just have peace everywhere? That'd be nice.
 
dmckee
dmckee
I happen to have coastal real estate for sale not far from Pheonix. And a couple of bridges in New York.
 
Danu
Danu
Nice, but too boring for the human race to be satisfied
now, I will go back to sleep
 
T Abraham
T Abraham
@Richard physics is fun.. that's why this was created (actually not) so we shouldnt be talking bad about each other..
 
Sabre Tooth
Sabre Tooth
12:45 AM
piece of what.... oh wait...
 
T Abraham
T Abraham
@Danu wait, u were sleeping?
 
Danu
Danu
oh, back to sleep... not what I meant
I'm not quite sober
 
T Abraham
T Abraham
@Emrakul exactly...
 
Sabre Tooth
Sabre Tooth
catch ya
 
ACuriousMind
ACuriousMind
@J.Musser @tpg2114 See, I told you that's why you saw the flags
 
T Abraham
T Abraham
12:47 AM
@ACuriousMind wait... you need to have over 10k combined rep?
 
J. Musser
J. Musser
@ACuriousMind I already knew that.
What's new
falls back into hibernation
 
ACuriousMind
ACuriousMind
@J.Musser I knew that you knew, I just wanted to link the comment for tpg to read. Could have gone about that craftier, perhaps...
 
J. Musser
J. Musser
@ACuriousMind lol, didn't even see that ping in there :) /me adjusts glasses
 
T Abraham
T Abraham
so if I have 1000 rep in each my account and have 10 accounts, I can moderate?
 
ACuriousMind
ACuriousMind
@TAbraham You see chat flags, nothing else
 
user61230
12:53 AM
@TAbraham You get access to some moderation tools in chat.
 
T Abraham
T Abraham
@ACuriousMind ah..thanks..
@Emrakul ah.. thanks..
Anyway, back to physics:

 Plants and Quantum Mechanics

To examine different aspects of a theory on plants and their r...
@dmckee lol..
bye friends...
 
tpg2114
tpg2114
1:22 AM
@dmckee Don't steal my real estate!
@ACuriousMind Wow, I wonder where the 20 flags that appeared and very rapidly disappeared before I could view them came from
And also, I left for like 10 minutes and fun stuff happened... lame
 
Mark Mitchison
Mark Mitchison
@dmckee I think it is as simple as the following. A plane wave of momentum $h/\lambda$ is not able to resolve spatial structure that varies over distances of much less than $\lambda$. Rather, one sees merely the average over a distance $\sim\lambda$. I do not know of any rigorous proof of this, however it is intuitively fairly obvious I hope. It is also borne out by my experience of the theory of quantum probes in general (not necessarily coherent beam scattering).
I guess the idea is that it is not possible to create non-negligible interference effects between two scattered wave where the scattering centres are separated by $d \ll \lambda$. (I am thinking in a sort of Bragg scattering picture here).
 
Kyle Kanos
Kyle Kanos
1:42 AM
Whoa. @Richard from SciFi.SE fame came into my chatroom. As did a few other famous people from across the network. WTF happened!?
 
David Z
David Z
@KyleKanos you have a chat room? :-P
 
Kyle Kanos
Kyle Kanos
@DavidZ I'm in here like 18/7, so I'm pretty sure it's mine ;)
 
David Z
David Z
works for me
 
ACuriousMind
ACuriousMind
@KyleKanos Flags were cast. The locusts came.
2
 
Kyle Kanos
Kyle Kanos
Seems that way. But doesn't really look like anything was done
 
J. Musser
J. Musser
1:46 AM
We looked at the flags - most of which were invalid
Why do I still have this tab open
 
Kyle Kanos
Kyle Kanos
@J.Musser Because you're being drawn now to the dark side of the SE network: physics
Coooooontriiiiiiiiiiiiiiiibuuuuuuuuuuuuuttttttttttttteee!
 
ACuriousMind
ACuriousMind
This is the h bar, not a black hole :P
 
J. Musser
J. Musser
@KyleKanos I'm not a physicist.
 
Kyle Kanos
Kyle Kanos
I do not see the problem ;)
 
J. Musser
J. Musser
Ok, here's my question:
5
Q: Why does the majority of smoke leave when flames appear?

J. MusserWhen I burn wood, paper, or other plant matter, where there is a flame, there generally isn't too much smoke, but it I blow the fire out, smoke starts billowing up. It billows thicker and thicker as the material gets hotter, and suddenly a flame springs up. At the same moment, the smoke dissipate...

thermodynamics everyday-life plasma-physics combustion
There, I contributed.
 
Kyle Kanos
Kyle Kanos
1:50 AM
Bam
My psychological warfare works with temporal oddities :)
 
J. Musser
J. Musser
I don't know much science other than biology.
Actually have three bountied unanswered questions on Biology.se if y'all are interested
 
Kyle Kanos
Kyle Kanos
Well, biology is applied chemistry, which is really applied physics ;)
 
J. Musser
J. Musser
 
dmckee
dmckee
2:05 AM
@KyleKanos I've steadfastly refused to post this on my office door. I feel it's the mathematicians' duty.
But I have posted:
 
Kyle Kanos
Kyle Kanos
We've been forced to remove our "decorations" like those :(
 
dmckee
dmckee
@KyleKanos Bummer. I just have to keep the window clear.
 
Kyle Kanos
Kyle Kanos
I work on the 1st floor of the building, which (supposedly) is where all the "important people" will pass when coming to see the Dept Chair (if that even happens)
 
dmckee
dmckee
Alas, a substantial fraction of SMBC's are NSFW.
 
Kyle Kanos
Kyle Kanos
Those on the 2nd & 3rd floor seem to be exempt
 
T Abraham
T Abraham
2:09 AM
Right now, I really need @alarge or @MarkMitchison ...
 
dmckee
dmckee
@KyleKanos I always wonder who these "important people" are who (1) don't understand academic culture and (2) simultaneously care how the little people get their jollies as long as they turn out the [whatever it is these guys want from us].
I've met people who fit either criteria, but none who meet both.
 
Kyle Kanos
Kyle Kanos
Yeah, I've never seen anyone from the dean/president/bigwig office come to my building
 
dmckee
dmckee
The dean comes to our building lunch.
And he meets with each search committee once, sometimes in our building.
But then my school has ~6000 students, so this is not a big place.
 
T Abraham
T Abraham
hey @vzn ?
 
Kyle Kanos
Kyle Kanos
I think my undergrad was around 5 or 6k students
And I seem to recall meeting the dean, totally not knowing who she was, and acting like it was no big deal while discussing my undergrad research at poster session
After she walked away, my advisor was like, "Whoa you handled that pretty well."
I was, "handled what"
 
dmckee
dmckee
2:15 AM
Nice.
 
vzn
vzn
lol its like "PHB" in dilbert. pointy headed boss
 
Kyle Kanos
Kyle Kanos
I haven't read Dilbert since I stopped getting the newspaper last year
 
T Abraham
T Abraham
@vzn please join my chatroom if u're available...
 
Kyle Kanos
Kyle Kanos
My wife never understood it
 
vzn
vzn
& that xkcd strip would be world famous if only they hired an illustrator :p
 
Kyle Kanos
Kyle Kanos
2:18 AM
@vzn Uh, I'd argue that it is world famous
 
T Abraham
T Abraham
@vzn their illustrations are good...
@KyleKanos yep..
 
vzn
vzn
re not being allowed to hang up cool stuff. recall that myself. "someone" ripped down all my cool collection once yrs ago ... actually it was also a science lab & a PHB :(
 
T Abraham
T Abraham
@vzn lol...BTW h stands for haired...
 
vzn
vzn
TA congrats on creating a room. not many do it. now comes the hard part.
 
T Abraham
T Abraham
@vzn u mean having members? why don't u join? or are u jealous? lol!
 
vzn
vzn
2:23 AM
xkcd also has a strip on the collatz problem. :) the guys a genius geek who unf also draws like one. maybe he could join up with watterson or something.
so KK wondering why you want to get out of the wonderful world of science/ academia into the wonderful world of finance....?
have you guys heard of larry gonick? hes great too. "illustrated guide to physics". old/ great...
"newspapers"... a dying phenomenon...
 
Kyle Kanos
Kyle Kanos
@vzn I guess my years in grad school have basically shown me that I don't really want to be in academia (not a lot of fun in grading, course prepping, & failing 90% of research proposals). So that really leaves industry
I have a brother in the finance industry who's been telling me for years that he can get me a job in the company, so I'm listening to that advice
 
vzn
vzn
afaik even sr scientists have trouble getting grants/ research proposals funded. is that what youre talking about? science is cool, but yeah, it has its limitations... went thru similar "career path" (so to speak) myself somewhat...
you might be interested to read about doyne farmer. very interesting character. similar story also.
there are some real hardcore scientists working in finance... long list...
 
Kyle Kanos
Kyle Kanos
The quant department at the bank I'd be working at is entirely PhDs in STEM fields
 
vzn
vzn
just remember every occupation has its hassles/ stress etc....
 
Kyle Kanos
Kyle Kanos
@vzn I have no doubt of that
 
vzn
vzn
2:33 AM
some quant finance jobs are real pressure cookers... but it will also be clear from the outset typically...
 
Kyle Kanos
Kyle Kanos
I think the pressure level depends on where and what your modeling.
 
vzn
vzn
defn have wished all my life that science had more cachet in this world...
 
T Abraham
T Abraham
@vzn u coming?
 
Kyle Kanos
Kyle Kanos
A few people I know who went to hedge funds made bank, but were stressed like crazy
The bank I'd be working at, in the few times I've visited it, I've not really seen many stressed people
 
vzn
vzn
exc recent book on subj "the quants" by patterson. read it few mos ago, really riveting.
hes got a new book on "dark pool" on my to-read pile.
 
T Abraham
T Abraham
2:38 AM
now why are u ignoring me?
 
vzn
vzn
two other interesting/ near legendary characters in finance: thorpe/ simons. both with sci bkgs
 
Kyle Kanos
Kyle Kanos
@vzn I'll try to remembering the books for the future
Right now, there's too much on my plate (the aforementioned Lewis book, Hull's Finance book, and Schreve's Discrete Stochastic Calculus plus that whole "writing my dissertation" thing)
 
vzn
vzn
heh right.
& maybe we would all do better in our fields spending less time in chat. :p
theres so much good writing on the quant field now, used to be more rare, tons of great refs now.
lately getting urge to work again on my own quant prj some more... long todo list...
 
T Abraham
T Abraham
@vzn what's it about?
 
vzn
vzn
looks for trends in stocks. using statistics/ machine learning techniques.
 
T Abraham
T Abraham
2:47 AM
@vzn ooo...so interesting.. you could get rich with that idea ! lol...
 
Kyle Kanos
Kyle Kanos
@TAbraham That's more or less the goal of quantitative finance....
(to find new ideas to make money for banks/companies/yourself)
 
vzn
vzn
there are very large hedge funds that make billions on quant-type analysis yes.
havent heard of too many "small shops" though.
there are some amazing deep connections between physics/ finance also, relatively new field "econophysics" or "phynance" etc
 
T Abraham
T Abraham
3:16 AM
@alarge u there?
 
 
1 hour later…
alarge
alarge
4:30 AM
@vzn, a lot of the quant buy side
boutique shops, where the money and the stress is, are rather small. The least stressful place is probably in model validation, so middle office of a large bank. With the new regulations and all those are hiring a lot, but quants often view them as deadends, career wise. Well, traditionally at least.
 
T Abraham
T Abraham
@alarge hello!
@alarge lol.. I know you're ignoring me..
 
alarge
alarge
That said, some of the best known physic Ist-turn-quants worked in risk management (derman), I think.
@TAbraham I am not ignoring you, I simply have nothing to say.
 
vzn
vzn
5:07 AM
derman, "my life as a quant," another great book on my to-read pile :)
there are certain types of quant jobs that have been around ages, maybe the model validation, but there are newer edgier types emerging within last ~2 decades.
 
alarge
alarge
@vzn I imagine the golden age of the math crunching quant is over, as stuff's becoming more computational (like machine learning, HFT). I don't think the econophysics stuff has really even convinced academics yet (but do add Sornette's book to your list)
 
 
4 hours later…
Gaurav
Gaurav
9:35 AM
@tpg2114 After going through the conversation transcript from yesterday, I think I've understood your argument. I have come to finally agree with you on that until evidence points to a dire problem in the way downvotes are cast, the benefit of doubt should be given to the present scheme of function.
@tpg2114 Please don't think my purpose to be here is to waste your time. I genuinly want to see something better for the site, and i felt putting my view across would be a good start for that.
And I'm really as less argumentative in real life as I am on the h bar. :)
 
 
4 hours later…
Danu
Danu
1:12 PM
Is there any real reason why it is conventional to call operators $f: X\to \mathbb{R}$ where $X$ is a Banach/Hilbert space functionals rather than the usual functions, which seems to be used only when $X$ is Euclidean space? I'm asking because I've realized that no such special word is used int he context of manifolds
...although, of course, one can argue that we're really working on Euclidean space when considering functions on manifolds
 
ACuriousMind
ACuriousMind
@Danu I think it is because the Banach/Hilbert spaces often are themselves already real functions, and someone thought that one should call functions of functions functionals.
 
Danu
Danu
Often, but not always, right?
 
ACuriousMind
ACuriousMind
Right
 
Danu
Danu
I guess my argument for the case of functions on manifolds suffices
I'm studying for my DiffGeo final :\ It's tuesday
had MQM yesterday, it was hell
 
Sabre Tooth
Sabre Tooth
boo
 
Danu
Danu
1:18 PM
...this again? :P
 
ACuriousMind
ACuriousMind
@Danu As expected, then? :P
 
Danu
Danu
Not at all, @ACuriousMind
much worse
 
ACuriousMind
ACuriousMind
I've got AlgGeo on Tuesday. Way too many weird definitions
 
Danu
Danu
It was an oral exam
and my entire exam was on a detail he'd spent less than 10 minutes on in the lecture
 
ACuriousMind
ACuriousMind
Uh...what?!
 
Danu
Danu
1:18 PM
:\
 
Sabre Tooth
Sabre Tooth
@Danu eh?
 
ACuriousMind
ACuriousMind
That sucks
 
Danu
Danu
namely, how to rigorously define Schwarz space, the space of tempered distributions and hte Fourier transform
-_-
 
Gowtham
Gowtham
@Danu they really like to do that , dont they ?
 
Danu
Danu
It felt really unfair
(I must admit that I didn't know this stuff properly)
It's just so irrelevant to what we'd been doing the entire course long
 
JamalS
JamalS
2:19 PM
@Danu Why don't you mention that to them?
 
ACuriousMind
ACuriousMind
@JamalS If they ask a question like that, it is pretty evident they don't care
 
JamalS
JamalS
Good point
 
 
1 hour later…
vzn
vzn
3:31 PM
alarge interesting assertion but from my pov it appears that its a new golden age of quants. yes centered around HFT/ML & large hedge funds etc & other stuff we cant fully imagine right now (eg bitcoin!). yes much more "computational" although thats a tricky distinction to make. (years ago it was mostly spreadsheets, now more code-oriented/ algorithmic.) there is quite a bit of interesting analysis of quant role in 2008 crash but from my pov its largely a red herring.
yes econophysics is a very young science but yet quite valid & maybe will help sort out a lot of the bogus science that has permeated "the dismal science" for long ages. re quants, you seem well read in the area, do you have some connection to the "biz"?
its a shame that there are some highly political questions re macroeconomics such as taxation/ regulation etc that likely have quantifiable scientific analysis/ answers but are subject to so much ... misconception and near propaganda ...
 
alarge
alarge
@vzn I agree: Quants want to blame quants, traders blame traders (see e.g. Das' Traders, Guns and Money), and so on. I suppose it makes one seem more influential than what one actually is.
As for the golden age of quants, I think the industry, like many other fields of science, are moving away from causation to correlation. Example: big data doesn't really explain anything, nor does it rely on physics-like postulates, but rather you correlate a lot of data and make predictions based on those links rather than on some mental/mathematical model/theory. This is to say that the skills required of the quants of today are different from those of Derman et al.
Econophysics is indeed young, and largely ignored among economists. In some sense the physicists entering the field are reinventing the wheel in many ways, which is not seen all that useful.
And I don't think taxation/regulation etc. can really be easily quantified. They are inherently political. Unlike physics, economics is not set in stone and as you change policies, the underlying "laws", too, change.
It is in this sense that physics is the easiest of the sciences: It allows for rather exact mathematical modeling, and once you have figured something out, it's not going to change (sure, you'll get better models but the original model itself will not lose precision as time goes by).
 
vzn
vzn
3:59 PM
some disagreement. money is a complex energy system subject to laws although that is still somewhat misunderstood. legislation/ legal laws adjust the energy dynamics of the system. ie parameters so to speak.
re causation vs correlation, big data. indeed a key part of future trends. however, my suggestion would be that big science is extremely interested/ focused in carefully isolating the difference between correlation/ causation like never before.
what changes somewhat is the scale. one can isolate real causation across many variables whereas before that was not so practical.
agreed, still a lot of speaking-separate-languages going on between econophysics/ economics. think econophysics has some very fundamental/ groundbreaking insights to offer & has done so already.
there are some basic energy laws of money roughly like F=ma probably now mapped out but not widely known/ embraced/ appreciated.
re "physics as one of the easiest of the science" ofc it is also one of the most fundamental & hardest too :)
reinventing discovery by nielsen has some things to say re impact of big data.
 
alarge
alarge
@vzn I somewhat disagree. This view can help in looking at some minute details of some subsystems (e.g. this), but the whole thing is based on human designed infrastructure, and I think in the macroscale this approach won't be of so much help (and things keep on changing, too).
@vzn I actually have this book on my bookshelf (and on that note, also the quantum information book by the same author), but have not managed to read it yet. A friend of mine was influenced by the book a lot and decided to write one paper in an open collaboration kind of way. I think about 20-30 people joined in on the effort.
 
vzn
vzn
4:21 PM
hi alarge studying collaborative science quite a bit for years re nielsen, polymath etc, also planning to blog on it in awhile, can you cite that collab science paper?
actually think that econophysics may be more applicable/ observable wrt macroeconomics than microeconomics! law of large numbers etc... have to dig up a paper on that, its been years since reading it....
think it was far more substantial than appreciated....one of those key papers that cant be recognized except on long hindsight....
basically it compared large economic systems to a thermodynamic gas behavior & finds ideal-gas-law like dynamics in std economics eqns.
individual economic agents are like energy particles that exchange energy/ momentum.
 
alarge
alarge
@vzn That is what one would intuitively think, yes, but I think it's false. The landscape depends so much on the institutions (like, say, the rise of shadow banking).
@vzn This is so idealized that I think it is largely useless. It's a fun model for a physicist, but I think these sort of models is why econophysics is ignored by economists.
Rather than agent based modeling I think it is behavioural finance that has really garnered a lot of interest in the past couple of decades.
There are maybe some universal "truths" in finance. Sornette has, for example, used the idea of fluctuations near phase transitions to predict stock market crashes. This has of course been used for fish populations etc. in the past, so it is not in a sense exactly a new idea.
But I believe that they have predicted several of the busts in the past 10 years or so.
But I think seeing scaling laws (something Mandelbrot first applied to finance, I think) is still far away from any sort of explanation.
Anyway, I think self-propulsion/active systems is poorly understood in physics, too, so I doubt we'll be seeing anything very useful in finance/economics for quite some time, either.
 
vzn
vzn
5:18 PM
yes the ubiquitous scaling laws in finance still seem poorly understood & maybe some theories will emerge to explain them.
the trick to macroeconomic econophysics models is that someone has to fit the data. the eqns are there but the data fitting is not so much. think this will be done at some pt & be groundbreaking/ paradigm shifting because theory/ data will mesh quite well at larger scales (law of averages).
am digging up old refs, maybe will blog about some of this at some pt.
 
DanielSank
DanielSank
@Danu: Fortunately once you pass your grad courses nobody cares what your grades are ever again.
 
vzn
vzn
as for econophysics "predicting" crashes, think that is an unrealistic/ unattainable goal except in general. think it will not show much more success than existing economics in this regard. its quite like "predicting" earthquakes. quite based on physical laws but nearly impossible to pinpoint.
predicting stock crashes is quite similar to predicting declines in stocks, an inherently "nearly-pure" random walk.
 
alarge
alarge
5:36 PM
@vzn Sornette et al have had quite a few successes, and there are similar stories from other fields. The idea is, in short, that near a phase transition the system starts to oscillate more (think, for example, metastable Ising model), and from these you can make predictions. It is not at all the same thing as predicting declines in stocks.
I think that the papers you posted are interesting, but I think of little real world value. The models are extremely idealized, and seem for example to gloss over liquidity, something that can be argued to have played a big part in the previous financial crash.
 
Iota
Iota
Check this out: tdoaps- the dreams of a physics student. A new webcomic that hopes to teach physics using comics. You can check it out here: medium.com/@tdoaps & twitter.com/tdoaps & facebook.com/pages/Tdoaps/1634335246802519 & instagram.com/tdoaps
More coming soon
Please like/follow
 
Sofia
Sofia
5:54 PM
@DanielSank Danny, you probably are good at such things as I have problems with. I have a stupid problem with Lienard-Wiechert potentials: a charge moves with constant velocity. Such a charge shouldn't radiate. But in the formulas of the electric and magnetic field appears the vector position of the charge, and it changes in time. So I get that both the electric and magnetic field depend on time. Someone told me that if E and B depend on time, I got e.m. waves. Is that true?
 
tpg2114
tpg2114
6:20 PM
@KyleKanos and/or @ChrisWhite Do you guys use immersed boundary methods at all? The idea is to represent interfaces (walls, or more likely in your cases phase changes) with something like a levelset that cuts through cells arbitrarily
 
Kyle Kanos
Kyle Kanos
@tpg2114 I'm vaguely aware of the immersed boundary method, but I do not use it
 
tpg2114
tpg2114
Bummer, okay
I understand the idea, but unfortunately (as always) the devil is in the implementation details
 
Kyle Kanos
Kyle Kanos
BTW: You'd be proud of me
I'm writing a code to read in some *.curve files
Using OOP-ish C++
 
tpg2114
tpg2114
Congrats! Branching out!
What are curve files?
 
Kyle Kanos
Kyle Kanos
It's for plotting lines
The format is # variable on the first line, followed by, e.g., position value for as many as you have
You can write multiple values in a single file by repeating e.g., # rho \n 0.0 10.0 \n....\n # px \n 0.0 5.3 \n ... and so on
VisIt reads it natively, so most of my 1D lines are done in that format
 
tpg2114
tpg2114
6:31 PM
Ah, okay
 
Kyle Kanos
Kyle Kanos
The curve files, in this case, contain the radial averages of my fluid variables
I'm going to make synthetic spectra of the photon spectrum from these files
 
tpg2114
tpg2114
Sounds interesting
My advisor just emailed me, he wants my PhD proposal in 10 days
I guess I need to start writing
Quickly
 
Kyle Kanos
Kyle Kanos
My proposal was 20 pages
Including a title page & reference page
So 18 pages of content (with loads of images too)
 
tpg2114
tpg2114
He said my introduction is supposed to be 20 pages. Then objectives another 5 pages. Then preliminary results should bring me closer to 50
 
Kyle Kanos
Kyle Kanos
Wow
 
tpg2114
tpg2114
6:36 PM
But a lot of it hinges on finishing this damn immersed boundary thing
 
Kyle Kanos
Kyle Kanos
Much more than I needed!
 
tpg2114
tpg2114
So I can get some preliminary results
My boss sucks. That's all I will say about that.
 
Kyle Kanos
Kyle Kanos
I recall some of your complaints before
 
tpg2114
tpg2114
It's gotten slightly better
Only because almost everybody quit
And so now I'm the only one with a clue of how things in the code/lab work
 
Physics Meta
Physics Meta
6:58 PM
0
Q: Reestablishing the "Thank you" policy of Physics.stackexchange

seuser32111This question is for deciding the "Thank You" policy of Phys.SE and meta.Phys.SE. Currently a user isn't allowed to say "Thank you" in his/her question. So, Upvote this question if you want that any user should not able to say "Thank you" in his/her question. Downvote this question if you w...

feature-request scope policy
 
Kyle Kanos
Kyle Kanos
7:18 PM
Would it be ironic of me to remove the "thanks" aspect to that Meta post (doing other edits too)??
 
user54412
@tpg2114 Alas no. I could see how they could be useful in certain situations, but most of the time boundaries are nicely aligned with cells. After all, there aren't many oddly-shaped walls with weird properties floating around in space.
 
DanielSank
DanielSank
7:42 PM
@Sofia This topic is not fresh in my mind. I would have to review my textbooks to help you with this.
 
ACuriousMind
ACuriousMind
@KyleKanos It would conform to established policy, at least :P
 
Kyle Kanos
Kyle Kanos
It's also an awfully phrased "question"
 
tpg2114
tpg2114
@KyleKanos I thought the same thing
 
Kyle Kanos
Kyle Kanos
The two choices should be independent answers
 
tpg2114
tpg2114
@ChrisWhite It can be used for gas/liquid interfaces too!
@KyleKanos Agreed, but I also don't really care enough to change it. Once the voting works out for a few days, just post an answer that says "Based on the vote count, it appears the community supports X"
Also, somebody bit on the migration map!
11
Q: Is there a map of migration pathways?

tpg2114While in chat lamenting a really bad question that was migrated to a site because 3 people voted for it elsewhere, we got to wondering: Is it possible to see a map of all the migration pathways in the vote to close lists? I know moderators can move things anywhere, but what can the normal close...

discussion vote-to-close migration
Absolutely no idea how the query works. It's pretty nuts looking
 
Kyle Kanos
Kyle Kanos
7:52 PM
@tpg2114 Cool!
 
tpg2114
tpg2114
The visualization is kinda cool, although hard to make sense of with so many variables (and the dataset is a really small subset because otherwise it wouldn't make the visualization)
 
Kyle Kanos
Kyle Kanos
@tpg2114 It should be an "vote on an answer below!" with the two options more clearly stated there (e.g., the emphasis on "not" and the up/down vote)
 
tpg2114
tpg2114
@KyleKanos I agree with you, but not enough to actually do anything about it. That's all I was saying
 
Kyle Kanos
Kyle Kanos
Yeah, I'm doing it now
:/
And I felt like being ironic since I was changing stuff too, so I erased the thank you ;)
 
Sofia
Sofia
8:14 PM
@DanielSank : this is my problem too. It is a longer time since I learnt such things than when you learnt them. And the teacher was a bad one ( a conceit fellow by whom all the students were idiots). Also, we learnt this topic superficially, without exercises, only the proof of the formulas and "good bye".
 
DanielSank
DanielSank
8:33 PM
Do you have Griffiths's EM book?
 
innisfree
innisfree
I'm writing an answer to a question, in which I want to link to an important paper (the discovery of the W-boson). As far as I know the paper is under copyright (behind a paywall at Physics Letters), but the Princeton university webpage hosts a PDF copy of the paper. What's the policy on linking to papers in this way? I guess it's forbidden?
 
ACuriousMind
ACuriousMind
@innisfree I think linking to copyrighted material in that way is forbidden, since the CC-something-something license under which all posts are published on SE requires all sources to be similarly "free".
 
Kyle Kanos
Kyle Kanos
@innisfree I'd provide the PhysLetter link or a DOI or whatever is similar. If they're a student, they can get it while on campus anyway. If not, they could get it if they so choose
 
innisfree
innisfree
That's a shame. I find it very annoying that such important papers are copyrighted. I'd like them to be available to everyone, in as many languages as possible.
 
Kyle Kanos
Kyle Kanos
It could also be that the Princeton page is hosting a rough draft and not the final copy
 
innisfree
innisfree
8:46 PM
No, it looks like the real thing, the header reads "PHYSICS LETTERS"
 
Kyle Kanos
Kyle Kanos
Ugh....reading bobie's edits just make me want to dive right into that "tar baby" of my own and delete it all
He/She just seems to have a vendetta against us for closing questions
It just doesn't make any sense
@innisfree I've seen preprints with official looking headers
 
innisfree
innisfree
Well, it would cost me $40 to find out if it matches the copyrighted version!
 
Kyle Kanos
Kyle Kanos
Totally worth it ;)
 
Sofia
Sofia
@KyleKanos can you tell me why I was punished? On an old question that I answered in the past I had a long discussion with Mark Mitchison. Unfortunately I forgot to introduce there a reference better than the one which was given in the post. I noticed that now and I made the change. And I was punished with 2 points. It's not just. 2 points are not big deal, it's only not just.
 
Kyle Kanos
Kyle Kanos
@Sofia Well -2 comes from someone downvoting one of your posts.
 
ACuriousMind
ACuriousMind
8:54 PM
@Sofia If the people downvoting you don't leave a comment, it is impossible for anyone else to tell you what they considered wrong/not useful about your posts.
Unexplained downvotes are something we all have to live with
 
Kyle Kanos
Kyle Kanos
And at some point, something you'll ignore as an ill effect
Hopefully it will probably still drive you to correct your post assuming there was something wrong)
 
Sofia
Sofia
@KyleKanos : How could someone downvote a closed question?
 
Kyle Kanos
Kyle Kanos
@Sofia Closing a question only means that new answers cannot appear. Votes still count on those closed ones
 
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