The h Bar

MartianCactus

1:00 PM

in a staight conductor carrying electric current, shouldnt there be infinite number number of field lines?

user116211

3 Who Studied Unusual States of Matter Win Nobel Prize in Physics

MartianCactus

as concentric circles originatre out of every point?

originate*

user228700

@0celo7 What was unclear about those sentences..?

0celo7

I don't know anything about Indian standardized tests

So I fail to see what that statement means

s.harp

@0celo7 I would have said that for an action of the symmetry group on the Hilbert space via $\tau_g$ that $\alpha_t\circ\tau_g=\tau_g\circ\alpha_t$ where $\alpha_t$ is the time evolution. But to be honest an analogous statement is already there in classical mechanics, where one does say symmetry breaking occurs.

user228700

1:01 PM

@0celo7 Right. Do u want me to explain?

MartianCactus

anser ma questions

0celo7

@MartianCactus not with that attitude

Sir Cumference

@0celo7 Oh yeah that's true

0celo7

@Kaumudi yes please

user116211

BREAKING NEWS #NobelPrize in Physics 2016 to David Thouless, Duncan Haldane and Michael Kosterlitz https://t.co/5jw75GIjRv

Tweeted by NobelPrize on October 4, 2016 at 9:47 AM

user116211

1:02 PM

@0celo7 I blame those digital papers.

0celo7

@s.harp To me, symmetry breaking means that you have a symmetry in the Lagrangian/action, but it is not realized on the level of the EoM.

Danu

→ 5 messages moved to Trash

0celo7

I think saying the symmetry acts on the space of states is exactly what that means.

MartianCactus

whats not with that attitude? @Oce

0celo7

(or symmetry of the Hamiltonian I guess)

MartianCactus

1:05 PM

in a staight conductor carrying electric current, shouldnt there be infinite number number of field lines?

as concentric circles originatre out of every point?

s.harp

@0celo7 I am sort of frustrated with the treatment of the topic in the literature I am reading. In classical mechanics one has exactly the situation you mention, a symmetry of the Hamiltonian will also be a symmetry of the eom via $\tau_g\circ\alpha_t=\alpha_t\circ\tau_g$, but for example in the double well potential one says the symmetry is broken, because if one looks at the behaviour the the system near the ground states one sees no trace of the symmetry.

This is not a very satisfying definition, but it could be that they understand it that pertubation theory around the groundstates doe…

MartianCactus

originate*

Farcher

@Heather Many thanks for your suggestion.

user116211

Lumo is apparently not so happy with the present awardings of the Noble Prize: Thouless, Haldane, Kosterlitz win the 2016 Nobel in physics.

user116211

> Just to be sure, the work by these three men is very closely related to the quantum Hall effect and the 1998 prize was for the (fractional) quantum Hall effect. Two prizes for that kind of stuff is arguably one too many.

user116211

1:14 PM

> So Barry Barish is probably happy that the Nobel committee has waited with the LIGO. (The January 31st deadline for the nomination could have been the reason that delayed the Nobel prize for LIGO, after all.)

user116211

The deadline maybe the reason indeed.

user116211

> Most of the journalists who were asking questions to Duncan Haldane – who was on the phone – were stupid and obnoxious females who asked questions like "where are the devices based on your work, Sir" and "why the hell did you do something as boring as physics that youth is increasingly uninterested in".

user116211

Dumb journalists ;P

user228700

@0celo7 OK. Two exams called JEE MAINS and JEE ADVANCED are considered the holy grail of exams in India. (JEE=Joint Entrance Examination)The scores on the first exam are taken as a standard benchmark for admission into many colleges here. MAINS is conducted for 3 hours and has 90 multiple choice questions, with a marking scheme that awards +4 marks to correct answer and -1 for the wrong answer.

user228700

If one clears the cutoff on this exam, one becomes elligble to write ADVANCED, which consists of two papers, conducted for 3 hours each, on the same day. The pattern of questions in this paper is entirely different and also, mostly extremely difficult. I should mention, at this point, that there is "reservation" of seats in colleges for different sections of our society; the cutoff for communities that used to be below the poverty line are marginally lower than for a "better off section".

0celo7

1:16 PM

Sounds like the SAT

user228700

People that belong to the " general" category have it worst because these people need to score much more to secure a seat in these colleges. So, in ADVANCED, if a student belonging to the general category obtains a rank below 2000, then he/she can join one of the IITS(Indian Institute if Technology). The people who did well in MAINS but not in ADVANCED, can join smaller colleges, called NITs(National Institute of Technology).

0celo7

Jesus never mind

user116211

@0celo7 yes; but the question level is higher.

user228700

And smaller colleges decide the merit if the student based on the marks obtained in the "boards"=final exams of 12th grade and also the marks obtained in MAINS. This is how students join engineering colleges. There are similar tests for admission into medical colleges, called AIPMT(All India pre medical test) and NEET(This has been introduced just this year; dunno its full form).

user228700

@MAFIA36790 Oh oh, SO much higher.

user228700

1:17 PM

@0celo7 Are u effing kidding me?! It took me 10 minutes to type all that on my mobile!

0celo7

@Kaumudi what?

@Kaumudi ok, good to know

user228700

@0celo7 You said " Never mind".

0celo7

what about people who don't want to do engineering or medicine?

@Kaumudi Yeah, never mind my SAT comment.

user116211

@0celo7 JEE covers general line too.

user228700

@0celo7 Yes, very good question. Thing is, not many parents encourage anything other than the sciences.

0celo7

1:19 PM

Don't you have a surplus of STEM workers then?

user116211

What is Barry Barish that Lumo frequently used?

0celo7

In America we keep pushing STEM but there aren't enough STEM jobs.

user116211

@yuggib: o/

user228700

There are some other highly prestigious institutions for research in pure science and these are the IISc(Indian Institution of Science) and IISER(Indian Institute for Scientific Research).

yuggib

@MAFIA36790 \o

user228700

1:20 PM

@0celo7 No, we don't have enough jobs. It's a terrible situation, really.

user116211

Barry Barish deserves a LIGO Nobel prize, too

user116211

Gotcha.

user116211

Lumo is awesome in reporting news ;))

user228700

@0celo7 Yes, exactly. There are hundreds of thousands of engineering graduates who are jobless at the moment, in my country.

user228700

BTW, you're allowed to take these exams only twice. I've taken them once already and didn't do that well even though my finals were awesome. So, I've taken the year off to prepare properly and write these exams again, next year.

0celo7

1:24 PM

Jesus

that's mucho crazy

user228700

@0celo7 Mucho? What do u mean?

user116211

@0celo7 THIS IS INDIA

0celo7

@Kaumudi do they not teach you spanish in Inidia?

user228700

@0celo7 Are u kidding me? LOL. No, they don't!

0celo7

well, it's a PhD level spanish word

means "very"

...I think

user228700

1:26 PM

@0celo7 Googled it. Yep, it means "very".

user228700

Anyway, all this is only the tip of the terrifyingly huge iceberg. There are institutions here, to which kids as young as 10 go, to start preparing for these exams.

0celo7

@Kaumudi You know in America we joke about you guys and school

the jokes don't do it justice

user228700

The competition is fierce. Close to 12,00,000 people write MAINS. About 1,00,000 people qualify for ADVANCED and finally, 10,000 people make it into IIT.

user228700

@0celo7 I see. Well, it's no joke to the students here. About 30 students as young as 14 commit suicide every year due to the pressure of performing well in a place called Kota here, which is the hub of the coaching institutes that coach u to ace these exams.

user228700

The number 30 might seem small but it's 30 families that die along with these children.

user228700

1:31 PM

It's effed up.

user116211

I never went to those coaching stuffs; they are bleh....

user228700

Yeah, clearly, I'm a little passionate about this. I've been struggling with all this crap for close to three years now.

user228700

@MAFIA36790 Not all of them are bleh but yes, self study works sooo much better for some people, like u and me. I did, however, attend FIITJEE in 11th and 12th and it was terrible. Hence this dropping a year.

0celo7

India is a strange place. People eating bricks, ridiculous standardized tests, etc.

user228700

EIC Outrage: Student Suicide Capital

►

user116211

1:35 PM

Good. I couldn't remain confined to the limited contents 11th and 12th standard books offered. That's why I never go to those coaching stuffs. I have some very good books that made my years ;))

user116211

@0celo7 Dude, don't narrow the country on this basis.

Secret

Why You Can Never Reach the Speed of Light: A Visualization of Special Relativity

►

user228700

@0celo7 I'd argue that every place with humans is a strange place, one way or another. The competition is crazy here, but America is pretty effing weird to us too, when reduced to the steorotypes associated with it. I mean, seriously, binge drinking. Why the hell is that a thing?

user116211

They have Trump. He will make US great again!!

user228700

@MAFIA36790 I'm not nearly educated enough on this subject to make intelligent comments.

Secret

1:40 PM

user116211

Anyways, my library has Bredon; but someone has already borrowed it. I'd have to wait then...

Secret

HK has similar shit going on. On average every March is suicide month

user228700

@Secret HK?

Secret

Hong Kong, my birth country

user116211

Hong Kong.

user228700

1:47 PM

@Secret Oh, that sucks, aargh! >.<

user116211

2:15 PM

0

Q: What is the Nobelprize 2016 about?

What are the achievements of this year's Nobelprize winners? What was their work about and what is/was novel about it? Disclaimer: This question is designed to give a thorough understanding of what the topic of this year's Nobelprize is about. The answer should give reference to most cited pape...

user116211

Too broad?

Jim

@MAFIA36790 Yes

Sanya

@MAFIA36790 too broad, very very very lazy

I mean, we should all be able to read a few articles and then come back with specific questions

but just dropping a few lines? come on ...

Shing

2:30 PM

I always support equality in rights for different genders... but face it, different genders are not equal... I still don't understand why male has to bear 90 % of the content during a conversation when he is picking up the girl..

user116211

Lumo is anti-feminist.

user116211

^^ Just a fact.

s.harp

@Shing how is this related to the chat? And I think your statement about conversations is not something that is generally applicable...

Shing

male has to bear 90 % of the content during a conversation, otherwise, the girls will feel bored, and just leave...

my books say, and I have experimented it... so true

it is about picking up girls

not general conversation

user218912

lol

s.harp

2:37 PM

So you think it is true wherever you are from, would you say it is true also in Namibia, France or the Philippines? Do you think it is also true for people 20 years older than you? Do you think the expertise of your book and your experiments can apply here?

And why am I even talking about this...

Shing

I am from Asia

not sure for those older than me around 20 years

never tried it

maybe I will try it someday

Qmechanic

@MAFIA36790 : Yes. The answers are e.g. given in the press releases on the Nobel web page.

user116211

@Qmechanic yeh; read at Lubos' blog.

user218912

@Sanya can you explain to me how interactions work in qft please?

user218912

last time my prof just added a negative $\beta\phi^4$ potential energy term to the free klein-gordon lagrangian and said it produces interactions.

user218912

2:44 PM

didn't explain why

s.harp

@IceLord I think that seeing how terms in the Lagrangian influence hte calculational rules of QFT (and so also seeing how interactions arise) is the main part of a first semester QFT course, so it is likely your professor will come back to this

unless you are doing an experimental particle physics course, in that case god help you

Sanya

@IceLord if you look at the Feynman diagrams, you can see that that term allows for vertexes in which two $\phi$'s go in and two go out - that's the reason there can be interaction through this term

but I'm really not the best person to ask about QFT ... so there will surely be people with better explanations around

user116211

@IceLord Shouldn't you go in office hours and ask your prof to explain?

Sanya

@MAFIA36790 do people really do that? :O

user218912

@s.harp okay, if you say so.

user218912

2:49 PM

@Sanya we didn't learn feynman diagrams yet.

user218912

@MAFIA36790 no because apparently he will explain in the future.

user116211

@Sanya ¯_(ツ)_/¯

user116211

@IceLord okay.

Slereah

Anything not quadratic produces interactions

Since free particles only happen for a gaussian measure

0celo7

3:06 PM

Proof?

Slereah

That's kind of the definition of free particles?

0celo7

But why?

You have to prove it

Slereah

You don't have to prove a definition

Hm, what would be a provable property of free particles

The dispersion relation, I guess?

How to express the freeness of particles through the dispersion relation

0celo7

what's a dispersion relation?

Slereah

The relation between the momentum and energy

Also interactive fields tend to decay

But then again that's not always true

Since there are soliton solutions

Maybe we could say that eigenstates of momentum of free fields don't disperse?

Not sure if that's generally false for interactive fields, though

0celo7

3:15 PM

@Slereah $E=mc^2$

Slereah

Sorry, we don't accept Einstein and the evidence here

ACuriousMind

@Sanya I think the American idea of the proper usage of professor's office hours is a bit different than ours

Shing

3:31 PM

@ACuriousMind what's it like in German?

ACuriousMind

@Shing Many professors don't even have regular office hours, it just says "by appointment" on their webpages and they'd not discuss questions about exercises or class material with you, since that's the TAs' job.

Shing

@ACuriousMind Are students encouraged to ask questions during lectures or after lectures?

ACuriousMind

Yes

You can typically see several students asking the lecturer questions in the break or afterward

David Z

20 minutes until our special chat session in the election room

Shing

3:47 PM

@ACuriousMind I see, thanks for answering.

Danu

hi

Self-Made Man

youtube.com/playlist?list=PLXy7t-HW0AY4qSAIPnscT-QAXFD-bXQ5V

I hope this lecture series will help you to understand solid state physics.

0celo7

@ACuriousMind most of my classes don't have TAs

Sanya

4:04 PM

@ACuriousMind that needs to be it - thanks :)

Danu

Special election chat session starting now in the dedicated chat room.

Emilio Pisanty

Testing for bold here so it won't muck up the moderator chat

↑ excellent, **bold** does actually work.

Danu

4:20 PM

@DavidZ Should I ask questions specifically aimed at rob in the current session, or later on?

David Z

@Danu hm, good question. Probably later. The only reason to do otherwise is that if we can put together a transcript on meta, it will only include questions from the chat session by default - though I have to imagine that's not hard to change.

Danu

OK.

Terry Bollinger

Ah, the dangers of having two chat windows up at once... Has anyone seen any good higher-dimensional geometric interpretations of SU(3)? Easy enough to find such stuff for SU(2), but I've not seen much for SU(3). (I assume this is OK to post here? Or has the idea of hbar chat for physics been overtaken by pure admin?)

Slereah

SU(3) is starting to be a bit high dimensional to be well represented

Let's see if it's homeomorphic to something

wikipedia doesn't list incidental isomorphisms for SU(3)

Danu

@DanielSank perhaps refrain from cluttering with non-question posts in the election chat.

(not sure---just my kneejerk reaction)

DanielSank

4:26 PM

@Danu Oh, sorry.

Yessir.

Terry Bollinger

I've already searched a lot farther than Wikipedia. It's not that there aren't excellent books & lectures on SU(3) out there, it's just that most of the SU(3) stuff seems to shy away from even trying to link into more geometric interpretations. Maybe Clifford stuff has something...

Slereah

I don't think SU(3) is the Clifford group of something?

Terry Bollinger

(Er, am I even supposed to be asking questions here? Has hbar also been taken over for election stuff also?)

@Slereah I don't either, which is why I've not looked it up.

Slereah

I'm sure there's some math paper somewhere about accidental isomorphisms of SU(3)

DanielSank

@EmilioPisanty Puns are offensive?

wut?

Emilio Pisanty

4:32 PM

@DanielSank Can be regarded as. Inappropriate, at the very least.

Slereah

SU(3) is already 8 dimensional, though

DanielSank

@EmilioPisanty TIL

Slereah

I don't think you'll find a relatable geometric interpretation

Danu

@EmilioPisanty I find this questionable :P But okay

David Z

Anything will offend somebody

DanielSank

4:33 PM

@DavidZ Hmmmm, let's test that:

David Z

@TerryBollinger it's definitely still okay to discuss physics here ;-)

DanielSank

Cute puppies

Danu

DISGUSTING

HOW DARE YOU

David Z

cat people

DanielSank

LOL

Danu

4:33 PM

KITTENS ARE THE ONLY

^^^

DanielSank

@DavidZ HAHAHAHAHA

Slereah

wikimedia.org/api/rest_v1/media/math/render/svg/…

Not overly informative

DanielSank

Hmmmmmmmm......

Emilio Pisanty

@DavidZ That's sort of the point. Anything will offend somebody, but playing fast and loose will offend more people. And offense caused by someone with formal authority is qualitatively different.

DanielSank

Ok... Newton's second law!

David Z

4:34 PM

@EmilioPisanty indeed

Sir Cumference

All right, my test is in 45 mins

Any tips?

Slereah

Succeed

Obliv

@sirC don't forget your pencil

Sir Cumference

@Obliv I got the point ;)

Pun definitely intended

Terry Bollinger

@Slereah thanks; nice to have at least one serious responder here. I'm abandoning ship for now. Too many insider jokes and not much physics here these days. Hi @ManishEarth, nice to see your name again.

ManishEarth

4:40 PM

o/

Obliv

@slereah in general does wave speed of a longitudinal wave depend on its amplitude of displacement? It's not clearly stated but I interpreted $v = \sqrt{\frac{B}{\rho}}$ to be that way since $B = \frac{\Delta P}{\frac{\Delta V}{V}}$ where if the displacement of the material is rather large $\Delta V$ is large. Then if the pressure difference associated with this change in volume is small, $\Delta P$ is small so isn't it somewhat dependent on amplitude? It's more of a natural amplitude

Danu

@TerryBollinger We're all in the moderator election chat room now!

ManishEarth

I'm around, I just don't say anything :)

Danu

There's an election going on!

Obliv

in reaction to the change in pressure, though.

s.harp

4:42 PM

@TerryBollinger does this go in the direction you are looking for?
http://mathoverflow.net/questions/69352/topology-of-su3

Terry Bollinger

@Danu yes, I gather @ACuriousMind is running, and I have zero idea why that is polarizing? Far too many conversations of which I know nothing. I'd like to think the overall focus is still primarily on physics? :)

Danu

@SirCumference Talk here

DanielSank

@Danu thanks for keeping the mod chat clean.

Danu

@TerryBollinger There were a few users that were very vocally opposed to his nomination.

@SirCumference stop talking in the mod election chat room.

Sir Cumference

@Danu Oh...

crap

Danu

4:44 PM

jeez :P

Sir Cumference

Sorry :/

Danu

@TerryBollinger I personally, and I think almost all high-rep users agree, think ACM is the best candidate.

But there have been a lot of "turbulences" lately, in the chat room etc. It's all a rather long story.

Obliv

yeah nvm to what I said earlier amplitude and the displacement of the fluid due to the change in pressure is different.

Terry Bollinger

@s.harp ah, nice, thank you s.harp! Yes, that is the kind of interpretation direction I'm looking for. I am an oddity in that I have toolkit of translations, scans, and rotations that make me surprisingly comfortable with assessing n>3 geometric relations, so I find it appealing to translate, or at least try.

David Z

@SirCumference Next time see if you can get the hint faster ;-) I was about to kick you out

Danu

4:46 PM

^

Sir Cumference

@DavidZ D:

David Z

(it will be quite a while until our next mod election, I guess)

Sir Cumference

I'm horrendously slow, I guess

Say, what ever happened to Chris White?

DanielSank

@DavidZ Because it depends on site growth?

@SirCumference He left. Don't start this again.

Terry Bollinger

@Danu Well ACM certainly knows physics and speaks well on issues -- understands questions -- so I hope that counts for quite a bit. Much of human contention is noise that needs to be filtered out over the long term.

Danu

4:47 PM

I think Alfred's answers are rather unsatisfactory. It seems he's not going to be (i) on meta (ii) in chat much at all...

Sir Cumference

@DanielSank Well, was kind of hoping to get some insight. Seems kind of taboo here.

DanielSank

@Danu Neither is Qmech or Manishearth.

Danu

@TerryBollinger Yeah, we agree on that :) I was mostly asking the question because I think it's something that some of the opponents really want to see answered.

David Z

@DanielSank yeah, pretty much. I'm just extrapolating from the 4-year interval between our prior election and this one. Obviously, if we have a couple people step down from the job, there will be another election at that time.

Danu

@DanielSank And I think that's a bad thing.

DanielSank

4:48 PM

@Danu Me too. In fact I want to ask why they're still moderators.

But I don't want to piss anyone off.

ManishEarth

@DanielSank (I used to be, but meta/chat tires me now)

Danu

@DanielSank QMechanic is extremely active/useful on the main.

DanielSank

In particular, I question moderator-ship being a life sentence. I know this has been discussed elsewhere already.

Danu

Like, way beyond anyone else on some aspects.

Sir Cumference

So, uh, kind of getting a bit worried I'm pissing off the high-rep users/mods

DanielSank

4:48 PM

@Danu Yes, he tags all the things.

Sir Cumference

Sorry then

ManishEarth

My schedule has been hectic since I'm working from a weird timezone, but in Novemberish I should have time to regularly participate again. Not posting, but doing more mod-things

sorry about the intermittent absences :)

Danu

But @ManishEarth---I have to say I'm not sure how much moderation work you're getting in... I mean no offense, of course.

DanielSank

@ManishEarth Right, but see this is why I don't like moderatorship being permanent.

David Z

@SirCumference what, about Chris? Nobody knows anything to tell you.

DanielSank

4:49 PM

What's the rationale?

Sir Cumference

@DavidZ All right then

Danu

lol @ManishEarth is making the users write an entire essay with that question :D :D

DanielSank

@Danu Yeah... I would just link to my meta post.

Essay done :D

user218912

@Obliv nice profile pic :)

Obliv

thanks @iceL it cut off the bottom but whatever.

user218912

4:53 PM

finally someone else with a blue profile pic.

user218912

idk what you people have against blue.

Obliv

hah knew you were going to say that

Terry Bollinger

@s.harp, @Danu, again, thanks! You both gave me the kinds of leads I was hoping for. Hey, it's @dmckee, hi! Anywho, heading off now, I'll look for election results. All, especially those agin @ACuriousMind, from my "just the physics please" perspective he or she is a pretty good candidate (I presume nothing!), I hope you will stay open to the option, but then I don't know the details.

David Z

@TerryBollinger you should probably vote, at least ;-)

Danu

(he)

@TerryBollinger He's the #1 candidate for most of us :)

Terry Bollinger

4:55 PM

@DavidZ good point, I will... quick link? Sorry to be so naive...

David Z

physics.stackexchange.com/election

Terry Bollinger

@DavidZ thank you sir!

David Z

no problem

Danu

The election chat was overall a pretty satisfying experience, to me. I'm happy we had one :)

I have now made up my mind about who to vote for, also.

0celo7

@Danu I could tell.

Danu

4:59 PM

@0celo7 Yeah? Could you also tell who I voted for?

user218912

ACM

0celo7

@Danu From what I read, I think I know who you're not voting for. ACM is a given, of course.

But I wasn't following the whole thing.

Obliv

@0celo7 whens ur nuclear test

0celo7

Even I voted for ACM.

@Obliv three hours ago

Obliv

oh that's pretty early. how did it go

0celo7

5:10 PM

Good.

I made a wild ass guess on the bonus and got it right

It was: would Chadwick have discovered neutrons if he used a Eu source instead of Rd?

There was a lot of superfluous info that was supposed to distract you

But that was the basic question

Obliv

yes

user218912

Idk what tablet to buy for reading/taking notes.

0celo7

@Obliv explain

Obliv

do I have to? it's quite trivial. Anyway, in the definition of intensity of a wave given by $I = \frac{P}{A}$ where $P$ is the power, what exactly is this power?

user218912

@0celo7 I forgot the details of the experiment.

Obliv

5:15 PM

I know the definition, time rate change in energy. But, energy of what? The wave? Is that usually constant if the wave speed is constant?

0celo7

The answer is in fact no because Eu doesn't alpha decay, and they used alpha transmutation to discover neutrons.

Obliv

[citation needed] @0celo7

user218912

@0celo7 LOL

0celo7

Why is that funny?

@Obliv Wikipedia.

user218912

so basically it's a trick.

0celo7

5:17 PM

Yes it was a trick question

They gave a table of half lives to confuse the test taker

Obliv

I have an idea. The power is the change in the amplitude of the wave as that would change the maximum & minimum KE/PE so that the total energy of the wave increases/decreases.

0celo7

Those are irrelevant

user116211

@ManishEarth \o/ waiting for that.

user218912

should I buy an ipad pro or a samsung note for writing.

Obliv

@iceL you can get a much cheaper tablet specifically for drawing/writing I think

user218912

5:19 PM

@Obliv like what?

Obliv

example: amazon.com/Wacom-Bamboo-Connect-Tablet-CTL470/dp/B005HGBEYS

user218912

that doesn't have a screen.

Obliv

Is it meant to? You said for writing.

user218912

you know how much space that will take up if I bring it to a lecture with my laptop?

Obliv

Just bring a notebook

yeesh

user218912

5:20 PM

my hand writing is so bad I can't read it myself.

0celo7

That's a sign of psychosis

user218912

mostly because it's too small and the ink spreads on the paper so it looks like a smudge.

user218912

@0celo7 ...

Terry Bollinger

@s.harp after looking over you link I'm going to thank you a second time. Not only does your link discuss the issue in detail, one of the answers also explains why there is a break in the ability to create diffeomorphisms to spheres as one moves from SU(2) to SU(3). That's why I was not having any luck finding such materials. Nice!

Obliv

@iceL your first problem was using a pen to take notes?

Just use a pencil

user218912

5:22 PM

I don't like pencil.

user218912

I only write in blue ink.

Obliv

of course you do. You probably only eat blue foods too

user218912

there aren't that many.

0celo7

@ACuriousMind I understand the WKB thing.

0celo7

5:40 PM

@IceLord pencil is superior.

user218912

no because it can be erased.

0celo7

Exactly

user218912

do you want someone to erase all your ideas?

0celo7

Yes because they're probably wrong

MartianCactus

so I need to get some terms clear...1 ampere is when 1 coulomb of current travels from the starting point of the circuit(the negative terminal) to the ending point of the circuit(positive terminal) in 1 second?

user218912

5:49 PM

wow low self-esteem. @0celo7

user218912

@MartianCactus ampere is just coulomb/sec, and current is not measured in coulombs.

MartianCactus

yes but it IS measured in amperes right? @IceLord

0celo7

Wtf how do you know that

Did you read Jackson?

MartianCactus

??

user218912

@0celo7 I am reading it, yes.

MartianCactus

5:54 PM

please explain

user218912

@MartianCactus yes

0celo7

@IceLord wow

MartianCactus

oh sorry, 1 coulomb of charge

user218912

@0celo7 well actually I'm reading notes that are following jackson, it's from a new course at my university.

user218912

I don't read old books...

MartianCactus

5:55 PM

dont think about terms before writing them :P

so..am I right on what I said?

user218912

yes.

MartianCactus

oh, ok

and the same goes for 10coulombs/10sec

user218912

@MartianCactus yes, the edited one is correct xD

user218912

you can also define coulomb in terms of amperes.

user218912

just the reverse of that, so 1 coulomb is the amount of charge carried by 1A of current in a second.

Obliv

5:58 PM

@iceL I don't think the original statement was correct? I could be wrong but isn't it the amount of current that passes through any point in the circuit through a given time interval?

MartianCactus

so if we get 1 coulombs in the first 6 sec and 9 coulombs for the last 4 sec...then the current for all 10 sec will still be 10amp but the current for the first 6 sec will be 1/6amp and the current for the last 4 sec will be 9amp

user218912

@Obliv yeah but isn't that the same as what he said just more generalized?

MartianCactus

isn't that right?

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