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user507974
user507974
12:23 AM
There is apparently a security failure on the meta physics websites, my browser wants to block access due to a vulnerability, any mods want to investigate. I'm using Waterfox 44 in case you are wondering
 
 
5 hours later…
John Rennie
John Rennie
5:12 AM
@user507974 is this relevant?
1
Q: I can't follow links from the h bar chatroom to meta.PSE. What's going wrong?

DanuWhenever I click a hyperlink to meta.PSE (as posted by e.g. the "Physics Meta" bot) in the h bar, I get the following screen: When I choose to proceed anyways (bottom hyperlink), I get this: Note that the URL looks like this: Some other times, I just immediately get this screen: I do...

bug
 
John Rennie
John Rennie
5:25 AM
@barrycarter Yes. If the light is a video feed of a clock on Earth then as seen by you it shows a picture of a clock showing t \approx -8 years. Obviously it will show a slightly later time because during your acceleration some time elaspsed and you got nearer to the Earth.
 
Anthony
Anthony
@JohnRennie Are you there?
 
John Rennie
John Rennie
5:55 AM
@Anthony Hi Anthony
 
Anthony
Anthony
@JohnRennie Hey, is there much in the way of graduate thermodynamics?
It seems like a very... simple subject, but we're spending a lot of time on it in my undergraduate class. I suppose there are things to talk about, but it doesn't feel as rich or interesting as quantum mechanics...
 
John Rennie
John Rennie
I don't know the area well, but no I don't think much if any leading edge stuff is done with thermodynamics these days.
But it's an essential part of every physicist's toolkit. Thermodynamics crops up in sorts of unexpected places e.g. quantum field theory.
 
Anthony
Anthony
6:08 AM
Oh really?
Ugh physics is too hard
 
skill patrol
skill patrol
not to mention most of physical chemistry
 
John Rennie
John Rennie
@skillpatrol all the sciences really. Even biologists have to struggle with thermodynamics at times. but I don't think thermodynamics itself is an active area these days.
@Anthony the problem with undergraduate physics is that it's trying to build up the toolkit you'll need if you go on to study it seriously. So it has to cram in lots of stuff that can feel a bit like just learning lots of disconnected facts. The magic starts when you do your PhD :-)
 
Slereah
Slereah
@JohnRennie What about geometrothermodynamics
 
John Rennie
John Rennie
@Slereah Google, google, wow that actually exists!
Geometrothermodynamics
In physics, geometrothermodynamics (GTD) is a formalism developed recently by Hernando Quevedo to describe the properties of thermodynamic systems in terms of concepts of differential geometry. Consider a thermodynamic system in the framework of classical equilibrium thermodynamics. The states of thermodynamic equilibrium are considered as points of an abstract equilibrium space in which a Riemannian metric can be introduced in several ways. In particular, one can introduce Hessian metrics like the Fisher information metric, the Weinhold metric, the Ruppeiner metric and others, whose components...
 
Slereah
Slereah
It does sound made up, doesn't it
 
skill patrol
skill patrol
6:18 AM
no magician would be complete without a few rabbits in his toolkit ;-)
 
Slereah
Slereah
It is a rather odd theory
You can have the METRIC OF A PERFECT GAS
 
John Rennie
John Rennie
Though it seems more like a bored theoretician having fun than any serious attempt to drive the understanding of physics forward.
 
Anthony
Anthony
6:32 AM
@JohnRennie That's good to know... I was starting to become disenchanted :P
Thanks.
I'mma hit the hay now
night everyone
 
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
cya later
 
user116211
6:52 AM
WTF!!
 
user116211
Kyle Kanos retired!!!
 
user116211
 
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
rly?
 
user116211
Should we give him a farewell?
 
user116211
Any opinion @JohnRennie @dmckee @DavidZ @Danu and all others?
 
user116211
6:57 AM
Like posting a Thank you for your contribution, Kyle?
3
 
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
On meta?
 
user116211
I know Meta is not for that but atleast he deserves that.
 
user116211
And history has encountered numerous times when at Meta MSE, Congratulations on reaching 100k were posted...
 
user116211
No matter how, we do need to give him a good farewell....
 
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ :((
 
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
7:01 AM
Huge loss to this site.
 
user116211
Damn.
 
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
Sᴋᴜʟʟ ᴘᴇᴛʀᴏʟ
I think he was starting a new job.
 
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ He didn't choose any physics career, I remember.
 
John Rennie
John Rennie
7:18 AM
I would be surprised if Kyle wanted any fuss made of his leaving.
 
user116211
hmmm.... okayish.
 
Slereah
Slereah
Hello
 
user116211
o/
 
skill patrol
skill patrol
o/
Aug 17 '15 at 2:47, by Kyle Kanos
I'm moving about 200 miles, which would be out of state. It is a permanent position.
He was a great contributor to this chatroom
 
user116211
7:37 AM
RIP Kyle?
 
user116211
Hmm... no; I would expect to see him in future.
 
skill patrol
skill patrol
Work In Peace
WIP
 
user116211
WIP Kyle Kanos :'(
 
user116211
I can't even ping him.... damn.
 
skill patrol
skill patrol
he probably wants it that way
 
John Rennie
John Rennie
7:54 AM
Damn, I've run out of milk and I hate black coffee. Oh no, what am I going to do? I'll die of caffeine withdrawal symptoms!
 
user116211
@JohnRennie !!coffee
 
skill patrol
skill patrol
In the beginning, I found it extremely hard to give up coffee.
 
John Rennie
John Rennie
@skillpatrol why would you want to give up coffee? Are you insane? :-)
 
user116211
why, in the world, would one give up coffee?
 
user116211
@JohnRennie: Great men think alike
 
John Rennie
John Rennie
7:58 AM
@MAFIA36790 Fools seldom differ!! :-)
 
user116211
I consume 4-5 cups coffee per day.
 
John Rennie
John Rennie
I only drink coffee in the morning, but I use a pint mug :-)
 
user116211
Hahaha!
 
user116211
Then you are not an addict.
 
user116211
:P
 
user116211
8:01 AM
In fact my monthly coffee bill is more than the electricity bill ;(
2
 
skill patrol
skill patrol
not good
 
user116211
damn
 
John Rennie
John Rennie
Coffee is a comfort thing for me rather than a stimulant. I start work around 6 a.m. and it's cold and dark. A hot mug of coffee is a crucial morale booster.
 
skill patrol
skill patrol
One or two cups is ok.
 
user116211
:(
 
skill patrol
skill patrol
8:03 AM
Try cutting back slowly @MAFIA36790
 
user116211
!!gun @skillpatrol
 
skill patrol
skill patrol
:(
 
user116211
My lunch is coffee and three Oreos.... the most delicious thing in the world ;P
 
Slereah
Slereah
Breakfast here was chocolate waffle
 
skill patrol
skill patrol
The first step is to admit to yourself that you have an addiction :P
 
user116211
8:06 AM
No! I'm not addicted ;(
 
user116211
I just like it.
 
skill patrol
skill patrol
Fine then. No problem.
 
user116211
It's not like I would die without that.
 
user116211
@skillpatrol :))
 
skill patrol
skill patrol
:)
 
user116211
8:08 AM
@Loong: o/
 
Loong
Loong
@MAFIA36790 hi
 
skill patrol
skill patrol
o/
 
skill patrol
skill patrol
8:25 AM
hi @ChrisWhite
 
Qmechanic
Qmechanic
9:16 AM
2
Q: Lattice theory in mathematics and physics

user40780I have undertaken a project examining lattice model and trying to construct algorithm that could work on all lattice (in physical sense, or crystal structure). I notice there is a branch in mathematics called lattice theory which deals with ordering. I am wondering whether the lattice theory in...

crystals lattice-model graph-theory
Too broad?
 
David Z
David Z
9:56 AM
@Qmechanic Yeah, I kind of think so.
 
FreezingFire
FreezingFire
10:06 AM
Hello everyone again! I would like to request an answer to this question: http://physics.stackexchange.com/questions/252347/what-happens-to-the-electric-field-at-the-boundary-of-a-dielectric?noredirect=1#comment556435_252347. I want to know why the equation $V = -\int E.dr $ for calculating V doesn't work if the path of integration crosses from one dielectric into another!
Thank you very much! Any help would be appreciated! :)
 
user116211
10:51 AM
@0celo7: o/
 
user116211
@TheGhostOfPerdition: what's up?
 
TheGhostOfPerdition
TheGhostOfPerdition
11:11 AM
@MAFIA36790 how are you?
 
user116211
Life is going.....
 
TheGhostOfPerdition
TheGhostOfPerdition
@MAFIA36790 I'm sure you would have cleared JEE Mains , Congrats !!
 
user116211
@TheGhostOfPerdition okay, not good.... only 165
 
TheGhostOfPerdition
TheGhostOfPerdition
@MAFIA36790 c'mon that is great !!
 
user116211
o.O
 
TheGhostOfPerdition
TheGhostOfPerdition
11:14 AM
@MAFIA36790 so whats up then? when is Jee adv ?
 
user116211
I don't know ;P
 
TheGhostOfPerdition
TheGhostOfPerdition
:/
 
user116211
No, actually I'd have to take a decision.... whether I would leave for another year or go ahead with it... my father tells me to join.... damn, I don't want to think of all that....
 
user116211
I'm just reading like any other normal day; preparing for NEST.
 
TheGhostOfPerdition
TheGhostOfPerdition
"leave for another year"? why?
btw what is NEST?
 
user116211
11:17 AM
@TheGhostOfPerdition Hmmm... my senior scored 189 in 2015; he took one year leave.... and now he scored 223.
 
user116211
National Entrance Screening Test
The National Entrance Screening Test (popularly known as NEST) is an annual college entrance examination in India, conducted for admission into the National Institute of Science Education and Research (NISER), Bhubaneswar and the Center for Excellence in Basic Sciences (UM-DAE CBS), Mumbai. These two institutes use NEST as a sole criterion for admission to their undergraduate programs. Also, the Integrated Science Education & Research Centre (ISERC) of Visva Bharati University has been using the merit list of NEST for admission into its undergraduate program for the last 3 academic sessions. NEST...
 
TheGhostOfPerdition
TheGhostOfPerdition
@MAFIA36790 ah thats okay, if your goal is to do integrated MSC in physics, then it should be fine, bcoz people joining CSE or ECE would be in much larger number
 
user116211
@TheGhostOfPerdition Yeh.... I am completely determined about my career.... that would be physics, that's it.
 
TheGhostOfPerdition
TheGhostOfPerdition
@MAFIA36790 great !!! I think you should go ahead this year itself, I'm sure you'd do great ! you are already great
 
user116211
remove that... you are exaggerating ;(
 
user116211
11:23 AM
I still found problems when revising old things.... how I can be great :(
 
TheGhostOfPerdition
TheGhostOfPerdition
That itself is a sign of greatness, non-great people dont revise :D
 
user116211
WTF!
 
TheGhostOfPerdition
TheGhostOfPerdition
:D, What is the temperature there?
 
user116211
@TheGhostOfPerdition: Hmm... just see my question list... full of such questions that you can't expect after clearing the boards.... I asked a question on wave recently; I couldn't stop myself but now I feel stupid on why I can't understand....
 
TheGhostOfPerdition
TheGhostOfPerdition
@MAFIA36790 But you are one of the rare gems curious abt physics, and being curious is all that matters if u ask me :D
 
user116211
11:39 AM
I hate flattery....
 
user116211
@TheGhostOfPerdition: okay, I have to go for studies,; bye o/
 
TheGhostOfPerdition
TheGhostOfPerdition
hehe okay, my manager will also kick me if he sees me doing this ;) :D
 
skill patrol
skill patrol
cya later
 
user116211
@TheGhostOfPerdition hahahha....
 
Secret
Secret
@Slereah Well, think about it, everything is basically geometry of some abstract spaces if thought hard enough
 
skill patrol
skill patrol
11:50 AM
@Secret is arithmetic basically geometry :P
 
Secret
Secret
well, numbers live in sets, and sets do act like mathematical spaces in some context
 
FrancescoS
FrancescoS
Hi guys! Does anyone know what are the physical applications of the Tree Matrix Theorem in Graph Theory? What is the use of this theorem in Physics?
 
Secret
Secret
@barrycarter This stuff strongly reminds of en.wikipedia.org/wiki/Rindler_coordinates
 
yuggib
yuggib
12:09 PM
@FrancescoS why should the theorem be used in physics?
I can imagine that if it is used, it is used in a rather indirect way...
 
FrancescoS
FrancescoS
oh, I found that this theorem is used to compute feynman integrals
And it is used in a direct way!
 
John Duffield
John Duffield
12:35 PM
@MAFIA36790 : I look forward to reading that answer.
 
ACuriousMind
ACuriousMind
@yuggib: May I get a mathmatician's opinion on: "The laws of the probability calculus directly follow - by pure reasoning - from the laws of the classical logic."?
In my eyes, this is complete nonsense, otherwise probability theory would not need (e.g. Kolmogorov's) axioms.
 
yuggib
yuggib
@ACuriousMind let's say that probability theory follows directly from classical logic in the same way that every theory does:
 
John Duffield
John Duffield
@MAFIA36790 : where's your answer then? It isn't on Noah's question.
 
yuggib
yuggib
i.e. by choosing a suitable set of axioms in a first-order logic language with rules of inference
and then studying a (subset of) the propositions of the theory
 
ACuriousMind
ACuriousMind
Yes, I agree.
 
yuggib
yuggib
12:50 PM
for classical probability theory à la Kolmogorov you need as usual ZFC (in a theory with $=$ and $\in$ as special symbols). Then essentially probability is measure theory
But I think that the quote means otherwise
and I also interpret it as pretty unclear, and maybe wrong
where did you get it from?
@JohnDuffield I think he was just quoting Arnold Neumaier
 
ACuriousMind
ACuriousMind
-1
Q: Does QM unequivocally violate the law of bivalence?

user3293056I had heard that QM violates the law of bivalence. Does anyone claim that?

quantum-mechanics
I'm getting into a fight with Lubos again :P
 
yuggib
yuggib
:-D
I refrained from commenting on that question
because there are so many subtle things to say
 
ACuriousMind
ACuriousMind
Well, then the question should be phrased a lot subtler. As posed, I say it is non-sensical because it is not clear how QM is to be interpreted as a formal logical system here.
 
yuggib
yuggib
there is actually a logic theory derived from "quantum mechanics" (non-commutative von Neumann algebras) where the truth value is not just zero or one, but any orthogonal projection
 
ACuriousMind
ACuriousMind
ValterMoretti talks a bit about it here
But nothing forces me to use "quantum logic", I can just be content with the quantum probability map not being a classical probability and live happily within standard logic.
 
lucas
lucas
1:03 PM
Hello. May someone help me to know "wrt" meant?
 
ACuriousMind
ACuriousMind
@lucas "with respect to"
 
lucas
lucas
@ACuriousMind Thanks a lot.
@ACuriousMind Forgive me. May you explain these sentences too. "The orientation is found from the directional derivatives wrt x, y and z. Please consult the tutorials. This is not a website for providing tuition."
 
user116211
@JohnDuffield I just found the quote interesting,; that's why I posted it. I didn't say anything to you, did I?
 
ACuriousMind
ACuriousMind
@lucas I don't know how to explain those sentences, their meaning seems pretty clear to me. What about them do you not understand?
 
lucas
lucas
@ACuriousMind I cannot understand those mean.
-1
Q: Determination of resultant force

lucasAs we know, force is product of pressure and area as below:$$d\vec{F}=Pd\vec{A}$$ P is a scalar and orientations of the small force and small area are same. I have three questions (they are approximately same): 1) Can we prove existence of resultant force? Is this formula correct? $\vec{F_r}...

forces fluid-dynamics vector-fields
@ACuriousMind May you explain a little?
please
 
user116211
1:12 PM
@lucas You don't have to pray... he would if he wants.
 
ACuriousMind
ACuriousMind
Well, the sentence "orientation is found from the directional derivatives" is simply wrong. I don't know what an "orientation" of a vector is supposed to be, but the "orientation" of a surface is given by choosing which of the two opposite normal vectors for it you choose.
Also, your question is not really a physics question, it's a question of how a surface integral is defined - which any text that writes down a surface integral should tell you.
 
lucas
lucas
@ACuriousMind "the "orientation" of a surface is given by choosing which of the two opposite normal vectors for it you choose." it is true for plane surfaces.
 
ACuriousMind
ACuriousMind
True for any surface - curved surfaces also have a normal vector at every point (for instance for the sphere it is either the vector pointing radially outward or the vector pointing radially inward)
 
lucas
lucas
@ACuriousMind I know surface integral. But in my case, there is orientation Under the integral.
 
Jester Tran
Jester Tran
is trace($A$) = trace($A^*$)?
 
ACuriousMind
ACuriousMind
1:17 PM
@lucas You cannot define a surface integral of a vector field without choosing a orientation.
 
lucas
lucas
@ACuriousMind "curved surfaces also have a normal vector at every point" this is true. But how we can indicate a finite curved surface by a resultant vector?
 
ACuriousMind
ACuriousMind
Since you are essentially projecting the vector field onto the normal vector, then integrating the resulting scalar function.
 
lucas
lucas
@JesterTran What?
 
user116211
@lucas Are you not working with differentials first and then integrating?
 
Jester Tran
Jester Tran
@lucas matrices
 
ACuriousMind
ACuriousMind
1:18 PM
@JesterTran $\mathrm{tr}(A^\ast) = \mathrm{tr}(A)^\ast$, clearly.
 
Jester Tran
Jester Tran
@ACuriousMind is that a typo on the right hand side?
 
ACuriousMind
ACuriousMind
@lucas I don't understand the question. What do you mean by "indicate a finite curved surface"?
@JesterTran No. The trace of the conjugate is the conjugate of the trace.
This is completely obvious if you write down what the trace actually is and then use linearity of the conjugation
 
lucas
lucas
@ACuriousMind We can define a finite plane surface by its area and normal vector.
 
Jester Tran
Jester Tran
@ACuriousMind ok ty
 
ACuriousMind
ACuriousMind
@lucas Yeah, but for a curved one, you have to attach the normal vector to every point of the surface. You can't even say what a "normal vector field" is if you don't already have the surface.
 
skill patrol
skill patrol
1:22 PM
isn't this a lot more fun than fighting with lubos again :P
 
lucas
lucas
@ACuriousMind So, the answer of my main question is "no" in your opinion?
 
ACuriousMind
ACuriousMind
@lucas Uh, what is your main question?
 
lucas
lucas
0
Q: Determination of resultant force

lucasAs we know, force is product of pressure and area as below:$$d\vec{F}=Pd\vec{A}$$ P is a scalar and orientations of the small force and small area are same. I have three questions (they are approximately same): 1) Can we prove existence of resultant force? Is this formula correct? $\vec{F_r}...

forces fluid-dynamics vector-fields
 
ACuriousMind
ACuriousMind
@skillpatrol Not really. :P
@lucas I don't see a yes or no question there to which I could answer "no"
 
lucas
lucas
@ACuriousMind may you answer it now?
 
ACuriousMind
ACuriousMind
1:25 PM
No.
 
lucas
lucas
@ACuriousMind Thank you.
 
John Duffield
John Duffield
@MAFIA36790 : oh, OK. No probs.
 
ACuriousMind
ACuriousMind
@3075: You seem...blue today. ;)
 
3075
3075
@ACuriousMind I'm always blue.
 
ACuriousMind
ACuriousMind
@yuggib: "You may completely misunderstand how the axioms of probability follow from the underlying logic but that doesn't change the fact that they're directly derived." Well, I knew from the beginning this would go nowhere...
@3075 Yeah, but your profile picutre has gotten even bluer
 
3075
3075
1:38 PM
Well I am kind of sad.
I want to study orbifolds but idk in what context.
 
user116211
melancholic blue
 
Danu
Danu
1:49 PM
@ACuriousMind I don't think you really disagree with Lubos there
He just refuses to acknowledge the difference between "directly derivable from logic" and "derivable using logic, given an axiomatic structure"
 
ACuriousMind
ACuriousMind
@Danu Well, then I disagree with him, because that is a crucial difference!
 
Danu
Danu
I don't think it's that crucial---presumably he views the axioms as "obvious"
 
ACuriousMind
ACuriousMind
You can't claim that axioms are obvious in a question about formal logic.
And it is crucial, because he also says that "quantum probabilities are exactly the same probabilities as those of classical statistical mechanics", which is blatantly false.
Quantum probabilities arise from non-commutative probability measures, which are not classical.
He's wrong, and it is not a subtlety.
 
Danu
Danu
His statements about QM do seem wrong (I didn't read everything carefully), that's true.
 
yuggib
yuggib
2:12 PM
@ACuriousMind It's not quantum logic, it's quantum set theory ;-)
@ACuriousMind why do you argue with motl...it's not worth
 
ACuriousMind
ACuriousMind
Well, I didn't find anything interesting to answer when first scrolling through the latest questions, so I had to do something else ;P
 
yuggib
yuggib
anyways I'm writing right now a paper about the Bohr correspondence principle in a probabilistic way...i.e. showing how classsical measures are recovered from non-commutative measures in the limit $\hbar\to 0$
lots of fun
@ACuriousMind I see ;-P Anyways you can always ask him for a proof using only logic...within ZFC it may be not so hard to prove basic stuff about measure theory
 
ACuriousMind
ACuriousMind
@yuggib You mean...a classical limit without handwaving?
that does sound fun
 
yuggib
yuggib
of course it is
and yes, no handwaving whatsoever
it will be on arXiv in a month maximum
the title will be "Limit points of nets of non-commutative measures on deformations of Weyl algebras."
 
ACuriousMind
ACuriousMind
A net is a generalization of a sequence, right?
 
yuggib
yuggib
2:22 PM
yep
 
ACuriousMind
ACuriousMind
Well, that sounds nice. Do tell when it is out!
 
yuggib
yuggib
in the case the space of the Lagrangian is not separable ;-)
@ACuriousMind yeah of course
it's essentially finished
 
Danu
Danu
@yuggib Is there any use for "summable families" (the supposed generalization of (abs. conv.) sums)?
 
yuggib
yuggib
I think it's essentially a fancy name for $L^1(I,d\mu)$, where $I$ is the index set and $\mu$ some measure
but I never saw it used in that way
in the sense that there are plenty of uses of $L^1$, but I never saw $\sum_{i\in I}x_i$, where $I$ is not countable
I think that the motivation is that summability depends a lot on the measure you choose, and there are plenty of them
for uncountable sets
 
ACuriousMind
ACuriousMind
@Danu That's not a true "generalization" - if the series over a family is finite, the family was at most countable to begin with, i.e. it's an ordinary absolutely convergent series.
I'm not clear why some people introduce the concept at all.
Hm, it might be a generalization in some weird topologies...
 
Danu
Danu
2:38 PM
@ACuriousMind What do you mean by "the series over a family is finite"?
 
ACuriousMind
ACuriousMind
If the sum of the family is finite.
 
Danu
Danu
I mean, how did you define it
 
yuggib
yuggib
ok, I found a reference to summable families
 
ACuriousMind
ACuriousMind
@Danu In the positive reals: Supremum over all finite sums.
 
yuggib
yuggib
and it is Bourbaki TG III.37
 
Danu
Danu
2:40 PM
@ACuriousMind Right
 
ACuriousMind
ACuriousMind
But, well, you have to give the definition of the sum, since you called the family summable ;)
 
yuggib
yuggib
and yes, essentially is supremum over all finite sums, and it is defined for any abelian Hausdorff topological group
 
Danu
Danu
So you're saying this is not a generalization at all?
 
yuggib
yuggib
and an arbitrary index set
 
ACuriousMind
ACuriousMind
On the reals, no
Every family that is summable in this way is already countable.
 
Danu
Danu
2:41 PM
Hmkay
 
yuggib
yuggib
it is not the supremum, but a family is summable if the filter of finite sums converges
in the topology of the group
and a result is that if a family is summable in a commutative group on which the identity has a countable neighbourhood system, then the $x_i$ are different from zero only in a countable subset of the index set $I$
always scan bourbaki :-)
@Danu How's your PhD going?
do you have chosen an advisor?
 
ACuriousMind
ACuriousMind
I think he's a master's student, not a PhD student.
 
yuggib
yuggib
ah
thought he was on PhD
and you?
are you almost graduating?
 
ACuriousMind
ACuriousMind
2:59 PM
After two months of trying, I have finally managed to get someone to be my examiner in the oral exam one has to do here before starting a master's thesis :D
 
yuggib
yuggib
Ah
so your graduation is supposedly next fall?
 
ACuriousMind
ACuriousMind
@yuggib I'm...not sure. The thesis stage formally takes 1 year, but half of that year is supposed to be "preparation", and how this is done seems to vary a lot between different advisors
So it's going to be at the latest spring next year.
 
yuggib
yuggib
I see
but PhDs often start in autumn, so it may be a little bit inconvenient
or useful for a nice holiday ;-)
he is relatively well known in the community of math phys...but I don't know if he's a nice person (and I also don't know well his work)
(if you're looking for advisor suggestions)
 
ACuriousMind
ACuriousMind
3:14 PM
@yuggib I know him, he's nice with a very dry sense of humor. I'm not sure his stuff interests me, doing renormalization and bounding integrals are not exactly what interests me in QFT
 
yuggib
yuggib
I see, and it seems that he shifted heavily back to physics in the latest years
the last mathscinet indexed publication he has is of 2008
the problem is that not much can be done in QFT if you're not willing to allow a lot of handwavy and probably false stuff
 
ACuriousMind
ACuriousMind
Have you heard anything about Walcher?
 
yuggib
yuggib
no, I don't know him
but he belongs to a different community
 
ACuriousMind
ACuriousMind
Ah, well, you don't care about geometry, right? ;P
 
yuggib
yuggib
on one hand is that, on the other people like him or the ones that @Danu talked about a while ago are outside of the community of math phys that I know of
I would say that they are more on the HEP community
but that's just my personal opinion; and in germany it seems they're considered as "mathematical physics"
anyways it's mostly a matter of names
 
ACuriousMind
ACuriousMind
3:25 PM
Hm, well, he publishes in hep-th, not math-phys on arXiv
I think Salmhofer is the only one here who has written in math-phys in the past
 
Danu
Danu
@yuggib I'm doing my MSc, like @ACuriousMind said.
 
ACuriousMind
ACuriousMind
It's mostly cond-mat lately, though
 
yuggib
yuggib
yeah I see
but he's still editor of comm math phys that is the journal of math phys
@Danu ;)
 
skill patrol
skill patrol
Which took you longer to complete @yuggib your physics PhD or math PhD?
 
yuggib
yuggib
@skillpatrol I have only one PhD
in math
I have a MSc in physics
and Bachelor as well
 
skill patrol
skill patrol
3:28 PM
I see.
 
yuggib
yuggib
in my country anyways you can't have multiple PhDs and be paid in each one
you can have a second one, but without grants
(and therefore it is not something people do)
 
Danu
Danu
@yuggib Yes, I'm working with the professor who is working with Mayr on this mirror symmetry stuff
Her name is Brunner
 
skill patrol
skill patrol
Her? ;-)
 
yuggib
yuggib
I gotta go now sorry, see ya later ;-)
 
skill patrol
skill patrol
cya later
 
FreezingFire
FreezingFire
3:32 PM
Where can i request answers of other members? Will someone please guide me?
 
Danu
Danu
@FreezingFire "Ask a question" on the main site
 
ACuriousMind
ACuriousMind
@Danu I know that name! My bachelor advisor wrote a few papers with her.
 
Danu
Danu
@ACuriousMind :)
In Amsterdam, everybody knew who she was, too!
But she doesn't have a ton of citations or anything
 
ACuriousMind
ACuriousMind
Well, I don't know anything else about her, I just recalled it from looking through his publications.
 
Danu
Danu
Right
 
FreezingFire
FreezingFire
3:36 PM
@Danu I have, of course. I read a meta post that says you could request answers of specific users, but i don't know how to address them directly! And my question has been posted here: physics.stackexchange.com/questions/252347/… for two days... so i thought of asking an answer here or somewhere...
Is it okay to ask answers here?
 
ACuriousMind
ACuriousMind
@FreezingFire What meta post? Usually, you do not "request" answers from specfic people, you just wait until they run across your question.
And two days is not much time, this is not a site that is supposed to work in real-time.
 
Danu
Danu
@FreezingFire you can also put a bounty on your question to attract more attention
 
FreezingFire
FreezingFire
@ACuriousMind This meta post: meta.physics.stackexchange.com/questions/6586/…. I understand, but anyways, i thought of asking an answer....
@Danu I'll try that when the second day completes.....And so sorry, its still 18 hours to bounty.....means about only one day has passed....
 
ACuriousMind
ACuriousMind
@FreezingFire And where does that say that you can "request answers of specific users"?
 
FreezingFire
FreezingFire
Would you guys consider answering my question, perhaps? @Danu @ACuriousMind
 
Danu
Danu
3:41 PM
No, sorry.
 
ACuriousMind
ACuriousMind
I don't have the first clue about dielectrics.
 
FreezingFire
FreezingFire
@ACuriousMind I'm sorry, it was this link: meta.physics.stackexchange.com/questions/1159/…
@Danu @ACuriousMind Thanks anyways.
I'll probably place a bounty....
 
ACuriousMind
ACuriousMind
@FreezingFire Oh...that's a four years old list. I don't think anyone remembers writing an answer there :P
@FreezingFire Why the hurry?
It doesn't exactly look like a question of life or death to me, what is so urgent about it?
 
FreezingFire
FreezingFire
@ACuriousMind Well, not exactly hurry, i was worried that the question would be buried under newer ones, and no one really would look at it, so i thought requesting answers may help.....
 
John Rennie
John Rennie
Should we close:
-1
Q: Is 12-6 Lennard-Jones potential smooth confining potential?

kensaiiIt's obvious that 12-6 LJ is a 2-body potential. The potential $V$ is said to be a confining potential $V(\pmb{q}) \to \infty$ whenever $\pmb{q}_i \to \infty$ or $||\pmb{q}_i - \pmb{q}_j|| \to \infty$. This means that at finite potential energy no particle can escape arbitrarily far away. LJ 1...

newtonian-mechanics potential-energy molecular-dynamics
 
FreezingFire
FreezingFire
3:46 PM
@ACuriousMind Well, your comments tell me that an answer can take a long time, so i'll hope for the best! Thank you!
 
Danu
Danu
@JohnRennie Pretty obvious YES in my mind.
 
ACuriousMind
ACuriousMind
@JohnRennie I'm all out of votes, but yes. The user doesn't even attempt to look at what the LJ potential does for $r\to\infty$
 
John Rennie
John Rennie
That was my thought, but I'm a bit stuck for a reason. We don't have a this is a self answering question close reason :-)
 
David Z
David Z
A custom reason would be appropriate.
e.g. "I'm voting to close this question because it doesn't show any effort."
In practice a lot of people would just file that under low-effort homework-like
 
John Rennie
John Rennie
@DavidZ speaking of which, can you delete this answer:
0
A: Difference in time for clock in attic vs clock in cellar

HansAccording to Wiki: Gravitational time dilation, the clock in the attic ticks faster than the on in the cellar due to weaker gravitation at higher elevation. So C is right.

or shall I flag it and let the mods sort it out at leisure?
 
David Z
David Z
3:50 PM
I got it
I don't think the flag is really important when it's such an obvious case
 
 
1 hour later…
skill patrol
skill patrol
4:59 PM
 
AccidentalFourierTransform
AccidentalFourierTransform
5:43 PM
user image
2
I think I'm gonna use this image very often in the Late Answers queue...
 
user116211
6:02 PM
@0celo7: .... o/
 
Physics Meta
Physics Meta
6:46 PM
0
Q: Is Physics SE a good place to ask for textbook references?

AndrewI sponsor a high school astronomy club. Most of my students have completed AP Calculus BC and are ready for a calculus-based discussion of astronomical physics. I am searching for a source-book to use for discussions at club meetings. Is Physics.SE a good place to ask "What is an overview of appr...

discussion scope books resource-recommentation
 
 
1 hour later…
ACuriousMind
ACuriousMind
7:51 PM
@AccidentalFourierTransform You think the usual answers in there have such a straightforward path as that rocket? ;P
 
AccidentalFourierTransform
AccidentalFourierTransform
8:39 PM
@ACuriousMind yeah, more like this, right?
user image
2
 
ACuriousMind
ACuriousMind
Better :D
 
skill patrol
skill patrol
lol
 
skill patrol
skill patrol
9:00 PM
@ACuriousMind do you get an option of which language to take your oral exam in?
 
ACuriousMind
ACuriousMind
@skillpatrol I think formally it would have to be in English since that's the official teaching language, but I could probably take it in German.
 
HDE 226868
HDE 226868
9:35 PM
@KyleOman Thanks for offering the bounty.
 
 
1 hour later…
Alfred Centauri
Alfred Centauri
10:42 PM
@JohnRennie Me too. I bring the horses and mules in from the pasture 'bout 6, give them their breakfast, and then come inside to the sounds and smell of a still brewing carafe of coffee. I make a cup, with a dash of half-and-half, take a sip, check email and news, and start working physics problems.
 
 
1 hour later…
ACuriousMind
ACuriousMind
11:44 PM
Hmmm...should a close review go on for three weeks? (and it's not even finished yet) What's going on here? Has everyone skipped that one? Is it for some reason not shown to everyone? (I don't recall ever seeing it in the queue)
 

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