lol +1 ... But not you. I like you. You're nice. meta.stackexchange.com/a/9694/196374

Not physics related:

Recently was thinking about a crime fiction where a criminal is being lured into a place where the undercovers, posing as an acting team is setting up a trap in the form that the audience were told that the criminal and the acting team have collaborated on a production thus they are all actors. This result in everything said by the criminal to be considered an act, and thus a hidden recording device then collects the criminal evidence spoken by the criminal, allowing him to be persecuted

But then I started to wonder, such scheme really cannot work in practice, because the criminal can dismiss everything that is recorded during the act as part of the script of the act

morning

Ordered Krasnikov's book

my poor money

money is the thing which is the most worthy to sacrifice for whatever thing you want.

Today I dreamt of multiple scenarios.

one is I was in a group with a man for class presentation. It's strange the teacher gave us an article without real contents to make presentation about it. We were discussing on what we should present.

@Secret entrapment is a tricky business.

If I have some operator $\hat{C} = \hat{A} +\hat{B}$ acting on some wave function. Can they retrieve different eigenvalues of the function? Or does the act of one result in the other being determined?

that misalignment is hurting my eyes

@Blue When did you become a Moderator wtf? :D Congrats!

@Chair Surely you can see the difference between referencing the fact that the meme once existed, and using it indiscriminately in the wild? As the link you gave shows, it's context that makes the difference here.

Please don't fall for the all-too-common behaviour trap of ignoring any and all context when it comes to SE chat

@Chair ok, fair, but if you're making that joke in that tone five hours later after everybody has gone, then you should also think about how your text reads in isolation

@Chair no worries

You can make food yourself

It is not too expensive

u can learn

there are many videos on youtube

@Blue Try cooking at your university instead

huh look at that, wikipedia defines online chat as "informal conversation" en.wikipedia.org/wiki/Online_chat

@Chair your guys prior (in)formal conversation in here :P

@GodotMisogi We used to make fast icecream with liquid nitrogen. Does that count as cooking?

@ACuriousMind I used to dream of pouring liquid nitrogen on some of my professors, so I guess it does count

You seem to have an...adversarial relationship with academia :P

lol! o_O

Nah, I think it's just one of the consequences of my hobby of anointing objects

uhhhhhhh

not gonna ask

@ACuriousMind That was at my previous university. HKUST is safe from my vandalism

@GodotMisogi holy cow someone into fluid dynamics around here— other than me... —small )( celebration ensues :)

@vzn Really? Fluid dynamics is currently ruining my life

hello

But we just started studying chaos theory and stuff, so that's fun

I hav a question on optics

@GodotMisogi oh geez now that sounds more typical around here :|

@Blue is there a relation between aperture and focal length? and why is a large lens used as the objective for telescope while a small aperture lens is used as eyepiece?

@vzn Flow instability is pretty interesting, moreso than any of the other material I've studied in fluid dynamics

@GodotMisogi thats more like it :) chaos theory is awesome :) are you undergraduate? US?

@vzn Nope, PG student/researcher at HKUST

What about you?

@GodotMisogi what is PG? software engr here working in industry (java+dbs+big data etc)

Postgraduate, but I think the US terminology is 'Graduate'

phd not masters degree?

Oh, I'm doing an M.Phil, not a Ph.D

can anyone look into my question please

I can't imagine working here for 4 years

fluid dynamics for Msc.Phil? philosophy?!? weird exotic :P

@vzn ...you realize that the Ph in 'PhD' also stands for "philosophy", right?:P

← lol oh yeah, thx for reminder, maybe got mixed up on this before, cyber dejavu

@vzn An M.Phil is a master of philosophy in some field; mine is in Mechanical/Aerospace Engineering. It's like one research degree below a Ph.D, which is usually awarded as part of a Ph.D programme. My research is focused on amphibious aircraft design, so fluid dynamics being involved is quite natural and headache-inducing

@GodotMisogi ok yeah but what area of physics is not "headache-inducing"? :P

Quantum field theory

LOL, I kid

QFT is only headache-inducing if you expect it to conform to any sort of intuition :P

@GodotMisogi yaknow fluid dynamics is showing up more in stuff like QFT... trying a different angle, is there some area of physics you like more than what youre working in? btw think you might think of looking into this new thing called pilot wave hydrodynamics :)

@GodotMisogi dear lord, I lost hours to figure out what was going wrong before I knew how that worked

I'll take QFT over that any day!

← dabbled in python recently repl.it + scikit learn way cool :)

@vzn Conversely, computational fluid dynamics has a renormalisation group model for turbulence

@GodotMisogi dont know about that but this reminds me of one of my favorite posts by hossenfelder on similarity of renormalization to fluid dynamics singularities...!

@GodotMisogi Since renormalization group flow is really a generic model for viewing the change of physical theories as the scale changes, this is not surprising

Like many techniques "from QFT", it is neither intrinsically quantum nor intrinsically field theoretic

@vzn I've realised that I'm not smart enough to engage in research of fields I'm very interested in, so I'm working on things that I find interesting enough that also give me enough free time (and money) to learn about the things I'm really interested in on the side

@ACuriousMind Like Feynman diagrams?

@GodotMisogi Yup, they're also essentially a generic model for organizing certain kinds of perturbative sums

> Note that the nonlinearity of the quantum field equations directly translate into strong nonlinearities of the macroscopic effective equations (Navier–Stokes, Boltzmann, quantum BBGKY). ... Quantum field theory predicts – under the usual assumptions of statistical mechanics, which include local equilibrium – hydrodynamics and elasticity theory, and hence everything computable from it.

I like how I'm dominating the starred comments right now

we like fresh blood newcomers around here :P

@vzn I say the same thing to freshmen undergraduates I match on Tinder

@GodotMisogi lol! was recently asking someone else about their gf around here and then got dinged for that :P

@vzn Yes, because there's a world of difference between making a joke about oneself and asking others invasive personal questions out of the blue. The latter isn't funny.

uh oh now mod hammer out :(

@Blue Does anyone actually use that?

Something was bugging me recently about some paper I read by Freeman Dyson. I think it was about Feynman being able to derive Maxwell electrodynamics theory via the commutator from QM

@GodotMisogi huh would like to see that, never heard of it. huge feyman fan myself noticed you cited FLP earlier. (visited caltech 2016, still have hat) :)

fermatslibrary.com/s/feynmans-proof-of-the-maxwell-equations

@GodotMisogi interesting! lol speaking of "jokes"...

Is arhttps a secure protocol for pirates?

No, I just made a typo because the notification boxes were blocking my edit view

@GodotMisogi Link is fixed now

So if Newtonian mechanics + QM commutator ⇒ Maxwell's equations, shouldn't you be able to derive Lorentz invariance and obtain a relativistically invariant QM theory?

Oh, Dyson asks the same question at the end of the paper

@Blue Fish today:

@GodotMisogi not an expert on this stuff sounds like an ether theory to me o_O ... think its worth further look... it seems loosely-to-more related to some angles/ leads have been pursuing

@JohnRennie Do you like fish sticks?

Goujons you mean?

If so then yes I do like them

@Blue yes :-)

@JohnRennie Sure, but then I can't make the joke

@GodotMisogi OK, what do I have to say to set up the punch line? :-)

@JohnRennie What are you, a gay fish?

South Park jokes really don't translate well into real life

@Blue Looks like your theory is failing

@GodotMisogi Dyson himself points out in that article that it is remarkable that Feynman derived Lorentz invariant equations from Galilean invariant assumptions

@GodotMisogi @ACuriousMind Yup, I noted that here

@GodotMisogi this is what am reminded of, think there is some analogy to particles in a perfect gas. sound waves in a perfect gas follow a relativistic form, have noted this in here before. have been trying to expand on this idea for years.

@Blue The lack of your Ubuntu customisation irks me

why is the pizza in a bucket

@Blue Eat. Now.

@Blue Papirus icons, Adapta theme

@GodotMisogi what is the meaning/ significance of your name?

@vzn Godot is one of my favourite characters from the Phoenix Wright: Ace Attorney series. Misogi refers to Kumagawa Misogi, the greatest villain ever, from Medaka Box

I usually say Godot is from Waiting for Godot by Samuel Beckett to appear sophisticated/idiotic

@JohnRennie could you help me with finding the probability bit?

@GodotMisogi there is a semifamous existentialist play called waiting for godot... oops lol you just cited it... had weird cognitive dissonance on 1st hearing about it from high school teacher (long time ago!)... o_O also googling turns up this en.wikipedia.org/wiki/Misogi

The possible results are $\pm \sqrt 2$

@GodotMisogi That proof is strange. If you replace all mentions of "commutator" with "Poisson bracket", this would morph into a classical proof that all forces are of the form of the Lorentz force.

huh other cutting edge google news Capcom Teases Phoenix Wright: Ace Attorney Trilogy Release Date bleedingcool.com/2019/02/20/…

@ACuriousMind Ah, nice idea. And converting the vector terms in the Lorentz force into scalar and vector potentials?

@Blue You'd be great at parties

@GodotMisogi Yes, sure. But that can't be right - certainly not all Hamiltonians contain a vector potential!

@Blue good man. The end of the universe could happen at any moment, and you wouldn't want to spend your last few seconds regretting not eating the pizza!

Ah, wait, one of the very first steps can only be proven by expanding the commutator and explicitly differentiating, so the commutator->Poisson bracket trick doesn't work

@ACuriousMind again, sounds like an ether theory

Also, I think we're missing commutator rules for $\ddot{x}$ for this to actually work

Also, the commutation rule $[\dot{x}_j,\dot{x}_k] = 0$ seems to be missing, in contrast to what we have in actual QM

If we add it, then eq. (9) becomes $[x_j, F_k] = 0$ immediately. making the rest of the proof pointless as everything is just zero

It's not a deep insight that you can write zero as the curl of a (equally zero) H-field!

feynman refused to publish it and dyson speculates on the reasons/ thinking for that decision. nothing to see here folks, move along™

It's odd that Dyson didn't mention that - if you assume that the velocities commute, like they do in QM/under the Poisson bracket, then the $H$ is zero and the $E$ is curl-free.

Ah, the issue is that the momentum is not proportional to velocity if there's a vector potential. In that case, the velocities indeed do not commute

So the assumption that "there's a vector potential" is basically hidden in the assumption that $[\dot{x}_i,\dot{x}_j]\neq 0$

@Chair I don't think improving the titles of closed questions is a worthwhile use of time, unless that would lead to them being reopened subsequently

@Chair In general, we try to make titles on SE as descriptive of the question as possible. If this is really done, there would be no duplicate titles.

@Chair And you know what? Without an account here, I can't even view the closed question. I can only view its duplicate!

@Chair Basically when I click on it, I get redirected to the duplicate.

@Chair If it didn't, frequent dupe targets would not amass so many views - random internet searchers that don't know SE will not click on the dupe link when they find a closed dup, so SE does it for them ;)

@GodotMisogi am very far from expert on this stuff as is probably obvious, and its lucky ACM was around to analyze this more deeply, but am intrigued at least as much as you are... am forgetting how lorentz invariance is typically "derived" but it seems to show the momentum-position commutation relation some how is deeply connected to it or implies it. it reminds me of the doppler effect... anyway nice find, hope to get into it further somehow...

googling... oh wow von neumann considered the "doppler speed meter" analogy wrt QM commutation relation :o link.springer.com/chapter/10.1007/978-4-431-54493-7_2

→ 7 messages moved to Trash

Hi $\hbar$

Howdy

Imagine you have a great research idea with results, and you want to publish.

Would it be a good idea to share and discuss it with someone else (probably a senior researcher in the field or your advisor) before publishing?

Or just publish as the sole author?

@Blue yes, especially when the idea is a noticeable one.

@Blue What if he asked you to add him as a co-author? Especially when he gives you some feedback and ideas to improve the paper, but they are negligible compared to the original idea. In this case, you will end up sharing the credit with him without having gained as much.

But you couldn't tell beforehand

@Blue scholar.google.com/citations?user=ytm_89IAAAAJ&hl=en

@Blue I think so

@Blue it is quite common practice to do just this.

in many cases the name of big boss function as seal of quality on the paper; in some cases you want them to be co-author to raise the profile of your own work.

This can be extremely frustrating for students who feel - in some cases quite rightly - that the big boss didn't do much.

I am not in favour of this kind of practice but it would be contrary to my experience to suggest it is rare.

I guess people doing computing can produce papers easily on their own easily even when they are still junior research students.

In comparison, it should not be easy for people in quantum theories to produce papers on their own in junior years.

working out a paper in statistical mechanics should be easiest in theoretical physics if computing is not considered.

Hi, everybody.

I am very tired. I may go to sleep very soon.

Sleep good

I think I will make some dreams I can remember. When I wake, I may tell you what I dream.

I can usually remember my sentiments accompanying a dream far more than its detailed scenario.

@Mo_ To be honest, I increasingly find that people often panic about "sharing the credit" without having a real understanding of how people read author lists in their field

Having your PI / advisor / other senior researcher as co-author does not mean that people will think 50% as well of your contributions to science as they'd do for a solo paper

so

@Mo_ yes, absolutely.