The h Bar

12:02 AM

@Bass No...I'm pretty sure that's wrong. I'll come up with a specific counterexample when I get home.

@0celo7 note that I'm not talking about general Lorentz transformations. Just boosts along the $x$ axis. Then $(1,0,0)$ and $(0,0,1)$ are orthogonal regardless of the boost.

There's length contraction along $x$, which does not change the angle between the vectors.

TanMath

hey @PhiNotPi

stay away!

I will protect my friends at h Bar

@quartata hello!

RikerW

I think it was @quartata actually...

TanMath

@RikerW hey!

want to talk physics?

RikerW

Sure.

Actually, how does Brownian Motion relate to the law of refraction?

TanMath

12:09 AM

@RikerW what in particular?

RikerW

Really, that has puzzled me for a while.

TanMath

@RikerW brownian motion and refraction? i cannot see the connection...

Brownian motion is like random motion of particles...

RikerW

sites.fas.harvard.edu/~phys191r/References/a7/Clark1970.pdf

0celo7

@Bass But we're talking about momentum, which always picks up a time part because of the mass shell condition.

TanMath

hey @DanielSank

@RikerW do you understand everything in there?

RikerW

12:18 AM

Not all, but some.

DanielSank

@BernardMeurer Please take @CuriousOne's comments with a cup of salt.

He tends to assume the brain on the other end of the conversation is filled with false impressions, and then argues against them, some times.

Bass

@0celo7 yes but we're talking about 3-orthogonality, which has nothing to do with the time component

DanielSank

@CuriousOne remember our private chat a while back in which when you finally stopped assuming I was full of moronic falsehoods that you actually wound up having your mind changed on the topic at hand?

I hope you won't forget that.

ACuriousMind

@Bass: Answered your question, I guess you must've been reading flowery prose about helicity :P

Note that you should not try to think about some electron trapped in a potential as in your example in the question. The statement about Dirac spinors and their helicity is for a free fermion, not some poor sod you've trapped in your lab.

DanielSank

@CuriousOne What theorem is that?

0celo7

12:26 AM

@ACuriousMind "hole" is feminine in Slavic languages (maybe not all) (cf. Czech mother)

DanielSank

@BernardMeurer Pick a field where you do both.

:D

I get to do both. It's fun.

Bernard Meurer

Hahaha Daniel easy for you to say!

ACuriousMind

@0celo7 Aha.

Bernard Meurer

I'll be in Santa Barbara along february

I was wondering if perhaps you would mind me sending you an email

TanMath

@DanielSank could you send a message to Prof. Mohseni?

Stephen Wong

12:38 AM

hello,anyone here?

TanMath

@StephenWong I am...

ACuriousMind

Nope, no one here.

Danu

@BernardMeurer That's not just a German thing :P

Stephen Wong

过两天我有一个电动力学考试

TanMath

??

0celo7

12:40 AM

間浜様はたまさん

Stephen Wong

That's Chinese

ACuriousMind

Google says: "I have a couple of days electrodynamics exam".

0celo7

Yes. I'm Japanese.

Stephen Wong

I 'm Chinese

Secret

@0celo7 it is,
@StephenWong so what in electromagnetism you need help from?

ACuriousMind

12:40 AM

@0celo7 "Mahama like Ball's"?!?!

0celo7

@StephenWong I deduced this.

Stephen Wong

How to rivew? Should I do more problems ?

Danu

@CuriousOne I think he did a lot of LHC phenomenololololo, no?

0celo7

@ACuriousMind Now you know my fetish...

Stephen Wong

And read the textbook again?

Secret

12:42 AM

@StephenWong From my experience, usually the best way to prepare for electromagnetism exams is to do more problems (unless you have already do a lot of it throughout your semiester

Danu

@StephenWong Redo the problems you already did.

Secret

which in that case, ensure you understand the key concepts to be assessed

Danu

This is by far the most productive way to study for 90% of tests I've taken.

ACuriousMind

::Has flashbacks to ~~electromagnetism~~ solving PDEs with boundary conditions::

user54412

@0celo7 Things being lost in translation is your fetish?

Danu

12:43 AM

Of course, this assumes you already know the basic ideas well enough to get at least a passing grade.

Secret

I once remember I almost fail my electromagnetism exam because I focus too much on revising concept and not dong enough problems

Stephen Wong

get it

Thank you guys

Danu

@ACuriousMind Lol

You should do gauge/gravity duality

all the boundary conditions :P

0celo7

@ChrisWhite No.

ACuriousMind

I made a quick timeline of when other sites were updated (based solely on when the list on meta was edited). The endpoint is today, Jan. 8, and the first point is Apr. 14 of last year. — Chris White 7 mins ago

user54412

12:46 AM

;)

ACuriousMind

@ChrisWhite: What urgent thing did you have to procrastinate so that you made that chart ;)

Stephen Wong

I go to study, goodbye

user54412

I just spent 4 straight hours with a postdoc trying to figure out... boundary conditions, actually.

user54412

Needed a break.

ACuriousMind

This theorem about matrices of linear maps doesn't look correct. Brilliant title :D

Danu

12:49 AM

@ChrisWhite Woop-dee-dooooo

Secret

---
[elaboration of the pattern of my questions using this example]
http://www.sciencedaily.com/releases/2015/12/151223130234.htm

"We can describe what happens in stripe formation using this simple mathematical equation, but I don't think we know the nitty-gritty details of exactly what molecules or cells are mapping the formation of stripes,"

Describe what happens using this simple mathematical equation = The mathematics

nitty-gritty details of exactly what molecules or cells are mapping the formation of stripes = The physics

Danu

"state vectors are linear" = nonsensical

ACuriousMind

@Secret wat

You really need to work on your communication skills. Less text, more information!

Bernard Meurer

I think @DanielSank scared @CuriousOne away

user54412

Also, it's definitely a bug in the chat system that enables so much to be posted at once. (Apparently including explicit linebreaks removes the character limit.)

ACuriousMind

12:59 AM

@ChrisWhite That's because it's intended to hold quotes

They don't expect anyone to try an explicit linebreak in chat unless quoting

I looked for this once on meta.SE

That's also why it says "see full text" - they assume it's a chunk of text copy-pasted from somewhere else.

user54412

Bizarre feature to build into the system. Don't post too much (unless it's not your own words).

ACuriousMind

Yeah, I'm not saying it's a sensible feature, either.

Stephen Wong

What are the key points of Classical Electrodynamics ?

Secret

(Not sure if this applies to your uni) Pontying's Theorem, energy in electromagnetic fields, Maxwell equations, Electrodynamics in matter (displacement current, polarisation, magnetisation, bound charges, bound currents, electric and magnetic dipole moments), multipole expansion, electromagnetic wave (vacuum solution to maxwell equation), Solving possion and laplace equations. Anything else to add on that guys?

Secret

1:17 AM

Actually, the true reason I line break is just to make my text easier to read (because I too hate reading blocks of text). But you are right, in the absence of equations I tend to get wordy and still working on it to simplify my conversations

Kyle Kanos

Hi

ACuriousMind

@KyleKanos Hi! What happened to your profile pic?

TanMath

^

Kyle Kanos

@ACuriousMind It changed

ACuriousMind

@KyleKanos You haven't, evidently ;P

Kyle Kanos

1:23 AM

@ACuriousMind Never!

I got bored of the SNR. Felt like going old school JRPG

I tried Thor in there, but that just was goofy

0celo7

Hello @KyleKanos

ACuriousMind

I'd guess it's from Final Fantasy, but I have no actual idea.

Kyle Kanos

@0celo7 Hi Ryan

TanMath

@KyleKanos his name is Ryan?

Kyle Kanos

@ACuriousMind It's a good guess. But too broad because there's like 40 Final Fantasies

@TanMath No

TanMath

1:25 AM

@KyleKanos then why did you say "Hi Ryan"?

Kyle Kanos

I bought a house (sorta...it's a rent-to-own)

0celo7

@TanMath Don't be silly.

TanMath

@0celo7 huh?

0celo7

Ryan? Lol

Secret

---
http://www.sciencedaily.com/releases/2016/01/160105133132.htm
*Should read up on the Ising model, and check whether the relative size of the system is also important (because of how in large wells the bacteria don't form patterns)*

TanMath

1:26 AM

^ cool!

Kyle Kanos

So @0celo7's having a baby?

ACuriousMind

@KyleKanos Since I don't know anything about them, I can't get more specific

TanMath

wait, what??

now that is rubbish...

Kyle Kanos

@ACuriousMind Too bad. They're good games. Better than flaming skulls or something.

Unless there's a bad guy in FF$n$ that has a flaming skull, then it's okay

ACuriousMind

How dare you...?

Kyle Kanos

1:28 AM

Very carefully, that's how I dare

0celo7

Flaming skull?

Kyle Kanos

Yes

A piece of bone that is on fire

Secret

Before that I have a hypothesis: Perhaps phenomenon predicted by Ising model will arise whenever the system approximated a lattice and that the relative size of the particle and the lattice achieve a certain critical value...?

0celo7

@KyleKanos Yes, I am with child.

Kyle Kanos

Sorry to hear, gonna have to drop out now?

ACuriousMind

1:29 AM

@0celo7 One of my older profile pics, don't you remember?

0celo7

@KyleKanos Nope.

@ACuriousMind Something something brain eating amoeba.

Kyle Kanos

@0celo7 Living off gov't handouts?

CuriousOne

Hello, again... apologies, I had to step out.

Kyle Kanos

"Don't apologize, it makes you look weak" - Agent Gibbs

0celo7

@KyleKanos No. Parents.

Kyle Kanos

1:31 AM

@0celo7 You have parents? I thought you congealed in a lab

ACuriousMind

Jan 29 '15 at 0:46, by DanielSank

I see chat as an asynchronous communication protocol.

0celo7

@KyleKanos Do you go around hitting people or just quoting the man?

Kyle Kanos

@0celo7 Pretty sure that's the first time I've quoted him.

CuriousOne

Did it get a little rough in here while I was away?

0celo7

Sadly no.

CuriousOne

1:32 AM

OK... just first impressions.

0celo7

These guys don't know how to have real fun.

Kyle Kanos

I know how to have real fun, but my wife's out at a party

2

CuriousOne

I went to a party once...

Kyle Kanos

This is a re-gift your ~~crappy~~ unwanted Christmas presents party.

Not interested in going. Plus, someone's gotta be home in case one of the kids wake up

Also: 29 more Late Reviews before I'm the first to get all 6 Review Gold Badges.

ACuriousMind

---there's no badge for that, is there?

Kyle Kanos

1:40 AM

I'm pretty sure I get stock options

ACuriousMind

How exciting.

Kyle Kanos

Well the market's been tanking, down like 1000 points this week

Effing Chinese sell-off

David Z

@HDE226868 ok

Kyle Kanos

For some time I actually wondered if I'd hit 10k close reviews before hitting 1k Late Answers. But then they changed it to <50 rep

ACuriousMind

I've been waiting for the Suggested Edit badge for ages, I never seem to catch many things in that queue

Kyle Kanos

1:46 AM

I've been ignoring that queue...there's enough activity on that one

0celo7

Finally home.

13 hour day.

idk how you working people do it

Kyle Kanos

That's almost a normal workday

0celo7

@KyleKanos Why would you think that

HDE 226868

@DavidZ Thanks.

Kyle Kanos

@0celo7 Bill Watterson once said he always was under the impression that bully's congealed in gym floors...I've always been amused by that line & finally got to use it

0celo7

1:51 AM

Why are there two stars on "how is the spin defined again"

It turned out that the precise definition in terms of helicity was indeed the key

dmckee

@CuriousOne I actually got invited to a party with the Hunt Club once.

0celo7

@KyleKanos I'm a bully?

dmckee

Your basic evening do, except that you get introduced to The Colonel who is clearly retired but liked his uniform so much he has suits made to a similar cut and apparently doesn't have any other name.

Kyle Kanos

@0celo7 No...notice I said you congealed in a lab and not a gym floor. Make the inference aaaannnd.....??

0celo7

@KyleKanos ...I don't get it

ELIyourkid

Kyle Kanos

1:53 AM

Think more than 20 seconds on it

0celo7

or maybe your kids are smarter than me

that's entirely possible

Kyle Kanos

My girls are funny

Not sure how that translates to smarts

0celo7

funny like haha or funny like whoa

CuriousOne

@dmckee: I was just trying to make a joke... in reality I was never invited to a party. :-)

2

0celo7

@KyleKanos uh

lab bullies are congealed in labs?

I don't get it.

dmckee

1:56 AM

@CuriousOne Well, I was very much out of place. No one wanted to talk about nuclear transparency, the forward pion production form factor, or where to find tamales in Tidewater.

0celo7

@dmckee Are those acceptable topics at the average collection of physics PhDs?

Kyle Kanos

0celo7

@KyleKanos Nerd bullies?

dmckee

Well, they're all passe now, but they were reasonable hot at the time.

Kyle Kanos

0celo7

1:58 AM

@KyleKanos ok just tell me what you were getting at

dmckee

@0celo7 Before your time. Very much before you time, you poor, poor dear.

0celo7

don't call me "dear", old man

you're not my aunt

ACuriousMind

On the internet, nobody knows you're an aunt.

DanielSank

@TanMath You're doing that thing again. I already said I would. Just give me the message. You can find my email on my profile page.

0celo7

@ACuriousMind I'm an uncle!

Kyle Kanos

2:00 AM

I'm an uncle

0celo7

wtf

TanMath

@DanielSank can I send the message here?

dmckee

@ACuriousMind Beat me to it.

Kyle Kanos

Like 8 times over

0celo7

is @dmckee $\cong$ H. Kissinger

dmckee

2:00 AM

Of course not. I'm your aunt. I thought we'd established that.

Kyle Kanos

^ Truth

0celo7

@KyleKanos I think I'm only 2+2+2=6xuncle

Kyle Kanos

I can't do math

0celo7

unless I'm forgetting some of them

Kyle Kanos

That's not very uncle-y of you

0celo7

2:02 AM

well they're not very memorable

I only like two of them

(the ones that speak English)

@KyleKanos Oh, you're saying I'm a nerd. Well I'm not, so no wonder it took me so long to get it.

Kyle Kanos

Secret

2:30 AM

http://www.sciencedaily.com/releases/2016/01/160108083918.htm
http://arxiv.org/abs/1504.00333
https://journals.aps.org/prd/accepted/9c071Y13Qf01b540790037d706f539446ab0764e8

(You can ignore the misleading (as always) science daily title and jump straight into the paper via the 2nd-3rd likes above)

Hmm...
Does the frequency of the oscillation of the alternate current has to be quite high because of how as seen from the lab frame, the gravitational waves produced by the electromagnets will have a smaller frequency than measured from the rest frame of the electromagnet?

CuriousOne

@dmckee: I like to talk about politics and religion at parties. It's the European way.

DanielSank

@TanMath I already mentioned my email...

Secret

PS I have read through the entire paper, except don't have time to reproduce their calculations

If only G was larger, then we would have warp drives already from the result of that paper...

CuriousOne

A. Füzfa? That's sounds like a Hungarian name. Never trust Hungarian physicists, they always like to build bigger bombs.

TanMath

@DanielSank fine! it is better for me to send it here

Secret

2:38 AM

Well, the maths looks quite legit to me, at least just inspecting some of the orders of magnitude that results

CuriousOne

I do have an even cheaper experiment that will also cause a gravitational signal... park a truck full of iron next to LIGO. That ought to do it.

Secret

that will work, except it is less flexible than switching on or off an electromagnet

CuriousOne

You can ask the driver to move it forth and back a little. At ten bucks an hour the modulation is cheap.

Kyle Kanos

Stan Shunpike

How many different ways can temperature change? For example, heat and work are often listed as factors. What else?

ACuriousMind

2:42 AM

@KyleKanos The only thing better than that would've been an appearance of Jar Jar.

Stan Shunpike

@ACuriousMind hey! How r u?

Secret

On his idea to make a gravitational wave transmitter, would we expect there will be more interference than our electromagnetism based information transmission methods because the wave will be distorted very easily as LITERALLY any energy momenta on the planet will bend spacetime in its path

I kinda doubt a gravitational wave internet is feasible given all that interference and much more possibility for the information to be distorted during transmission

Kyle Kanos

@ACuriousMind Jar Jar is Snoke

ACuriousMind

@StanShunpike Hi! I'm fine, thanks!

@KyleKanos mind=blown

Kyle Kanos

Well that's the theory anyway

ACuriousMind

2:44 AM

I liked the Plagueis theory better

Stan Shunpike

I havent seen the movie

facepalm

I've realized my favorite part over time is John Williams music

Kyle Kanos

Your fault for going on the internet while not having seen the biggest movie of all time

Secret

3:08 AM

On closer thinking about this interpretation (and in fact how a wavefunction is commonly introduced in some introductory quantum text as "contains everything we can know about the quantum system"), it is tempting to associate this with the semiphilosophical idea that we are living in a simulation

The only question is then, does the fact that the formalism of a wavefunction (or in general a quantum state) works so well in modelling nature necessary implies nature is a simulation? If not, than how would a wavefunction like notion in a non simulated reality differ from a simulated one (where …

0celo7

3:23 AM

@ACuriousMind hmm

is Sidious not capable of killing someone for good?

Kyle Kanos

I'm about 95% sure that Snoke is really Gollum

ACuriousMind

@0celo7 Well, Plagueis was supposedly aiming to obtain power over life and death, so...perhaps he succeeded a little.

Kyle Kanos

And I commented to my wife in the theater about Snoke being Gollum without at all knowing that Andy Serkis did do both roles.

DanielSank

@KyleKanos Are we done with the Star Wars spoiler ban?

Kyle Kanos

@DanielSank There was a Star Wars spoiler ban?

DanielSank

3:28 AM

@Secret "The only question is then, does the fact that the formalism of a wavefunction (or in general a quantum state) works so well in modelling nature necessary implies nature is a simulation?" <-- No.

At least, I don't think so.

I'm not even sure what that means though.

@KyleKanos Sort of.

I asked people to not spoil, and it was starred.

Kyle Kanos

@DanielSank Oh.

<- not been in chat for like ~3 weeks

ACuriousMind

2 days ago, by Emilio Pisanty

Stan Shunpike

Is energy conservation in thermodynamics the same kind of conservation as in Noether's theorem?

DanielSank

Yah, and at this point if someone doesn't want it spoiled they should probably not internet at all.

Kyle Kanos

41 mins ago, by Kyle Kanos

Your fault for going on the internet while not having seen the biggest movie of all time

Still kinda annoying that almost every question over at SciFi is about TFA

DanielSank

3:31 AM

Meh.

To be expected.

Kyle Kanos

Of course, but half the questions are speculatory. Just wait 2 more years

Stan Shunpike

@0celo7 can ya help me on this one?

Kyle Kanos

(less than that, it's planned a May 2017 release, IIRC)

ACuriousMind

@StanShunpike Uh, why wouldn't it be?

DanielSank

@KyleKanos Oh come on, it's fun!

Kyle Kanos

3:32 AM

@StanShunpike No, Noether's theorem only applies to classical mechanics.

And nothing else

Especially not pseudo-science stuff like QFT

DanielSank

@KyleKanos Oh god, why would you say that.

Everyone, get on your flame-proof undies.

Kyle Kanos

@DanielSank Because I'm me.

Stan Shunpike

grabs fire extinguisher

DanielSank

@StanShunpike I got a laugh out of that. Thanks.

Stan Shunpike

If I understood correctly, you guys disagreed.

Was @KyleKanos fibbing?

Kyle Kanos

3:34 AM

I never lie

DanielSank

^ False.

Kyle Kanos

That's impossible to be false

DanielSank

^ False.

Kyle Kanos

Okay. Depends. What am I being claimed a fibber about?

DanielSank

@KyleKanos Nobody accused you of anything.

Kyle Kanos

3:36 AM

2 mins ago, by Stan Shunpike

Was @KyleKanos fibbing?

Stan Shunpike

That's a question not an accusation.

Kyle Kanos

Well good thing I said claimed and not accused

Stan Shunpike

I don't think a question is a claim either.

Kyle Kanos

I said a few things that might be construed as incorrect

Stan Shunpike

XD

Ah

DanielSank

3:38 AM

I vote we vote @KyleKanos out of office for lying.

We can do that?

Yes.

Impeachment on SE?

nods

Hmm

Well I disagree to your rules then

DanielSank

3:39 AM

@KyleKanos To bad, you're in accused-of-lying box. Your opinions count 1/3 when in the box.

Kyle Kanos

Well it's a good thing my opinions account for 99/2 when I'm out of the box

TanMath

in Discussion about linear response theory, 22 hours ago, by TanMath

@DanielSank what about the damped oscillator one?

Secret

(elaboration of question 1)
@DanielSank Wavefunction is "everything we can learn about the quantum system"-translation by you-> a quantum state is just a thing which represents the information available relative to a particular subset of the universe

Information in physics=what characterise and distinguish one system from another-> reminds of digital information on internet

Therefore wavefunction/quantum state works like digital information?

Therefore the fact that this model works really well in predicting quantum experiments suggest our world is somehow governed by something analogous …

Q2: how would a state in a non simulated reality differ from that in a simulated reality in a way that it can be experimentally detected? (because in a non simulated realty, there is nothing analogous to "bits" (I suppose...?)

0celo7

3:59 AM

@ACuriousMind well it was always implied it was power over everyone but himself

I was going to google something

Now I forgot what I was going to google

or was I going to get a drink

maybe make some popcorn

All I know is I alt tabbed out of AssCreed IV and got distracted by SE

now I have no clue why I alt tabbed

argh, I'm getting old

DanielSank

4:51 AM

@Secret Why does digital versus not digital matter?

@Secret Uh yeah. I claim the quantum state is information so your statement "information works like information" is definitely acceptable.

"Therefore the fact that this model works really well in predicting quantum experiments suggest our world is somehow governed by something analogous to digital information, hence our world acts like a simulation of sorts?"
^ I'm definitely not seeing that.

@Secret You're asking if it's possible to tell whether or not we live in a simulation. I think that's a definite "no".

Secret

actually, does a simulation need something that behave like bits to exist?
Is it possible to have a simulation that is not run on bits?

my confusion might be stem from thinking that a simulation requires digital information, or bits

but I am actually not very sure about that

0celo7

5:31 AM

GTA 5 - Bowling Bling (Hotline Bling Parody)

►

user54412

8:55 AM

A question is asked whose only flaw is being solve-my-work-for-me. It's closed instead for insufficient prior research, which of course isn't a valid close reason and doesn't apply anyway. It's nonetheless answered by the primary closer in the comments. An answer wants it opened because there is good physics there, and the asker leaves satisfied with an answer. What exactly is a reviewer to do with this mess?

Bass

9:59 AM

@ACuriousMind thanks for answering! I just saw that the whole potential thing was completely unnecessary. My question is just about how the spin 3-vector from NRQM transforms under Lorentz boosts.. gonna add an edit

Slereah

11:08 AM

Hm

The whole Haag–Lopuszanski–Sohnius theorem says things about the symmetries of a quantum theory

Basically internal + Poincaré + some susy stuff in 4D

Does that mean you can't have conformal symmetry

Bernard Meurer

12:19 PM

Morning folks

ACuriousMind

1:28 PM

7

Q: How does a SCFT avoid the Haag-Lopuszanski-Sohnius theorem?

According to the Haag-Lopuszanski-Sohnius theorem the most general symmetry that a consistent 4 dimensional field theory can enjoy is supersymmery, seen as an extension of Poincarè symmetry, in direct product with the internal gauge symmetry. But we know that conformal theories, having as a symm...

Someone else already wondered that ;)

alarge

1:56 PM

@Secret Well yes, you do have to approach the thermodynamic limit for most of the stuff to have a crisp meaning. en.wikipedia.org/wiki/Universality_(dynamical_systems) may also be of interest to you.

0celo7

2:26 PM

@ACuriousMind is the current $j^\mu$ or $J^\mu$

@ACuriousMind I remember you once saying you'd be up for putting bounties on questions once you hit a certain rep...I'd appreciate you considering placing one on this question of mine.

alarge

2:52 PM

Anybody code webstuff? Suppose I wanted to make an interactive physics simulation and have it on a website. In the olden days people used Java applets, but I'd prefer something that should work with a range of different devices and be relatively futureproof. Performance is not that much of a concern, but is always nice to have. What rechnologies would you use?

2

ACuriousMind

@0celo7 I'll consider it

@0celo7 wat

Physics Meta

0

Q: Downvote caused upvote

I just tried to down vote an answer. The vote count went up. I hit the down button again, and the count went up again! I'm afraid to try it again. FYI