The h Bar

privetDruzia

20:00

if you derivate the potential energy you get force

so this is only in one way

Bernard Meurer

Why are people speaking klingon?

3

privetDruzia

the differential operator is not inversible

dmckee

Because they can?

FenderLesPaul

@privetDruzia yeah it is

you use an integral

privetDruzia

(sinx+6) ' = cos(x)

dmckee

20:01

@FenderLesPaul Which either yields a family of answers or requires the input of an additional fact (the boundary condition).

DanielSank

@BernardMeurer It's Russian spelled out horribly with Roman alphabet.

FenderLesPaul

I can equally well define potential energy by $U = -\int dx \cdot F(x)$ or force by $F(x) = -\partial_x U$

privetDruzia

and now the other way around

Mike Miller

@FenderLesPaul: Which is a right inverse to differentiation, but not an inverse.

privetDruzia

you don;t know the constant

FenderLesPaul

20:01

@privetDruzia the constant is an arbitrary shift in potential energy

it isn't physical

we only measure differences in potential energy

DanielSank

^ That

privetDruzia

mhm ok

FenderLesPaul

which is the boundary condition @dmckee mentioned

privetDruzia

wooow @DanielSank

DanielSank

@privetDruzia ?

Bernard Meurer

20:04

@DanielSank Ooooh, that makes more sense

privetDruzia

so u r in nanoelectronics I presume

based on u r profile?

DanielSank

@BernardMeurer :D I love Russian. It is the most beautiful language I know.

@privetDruzia You could say that.

privetDruzia

that seems really crazy, especially if you are working for google I guess.

I study electronics and IT for space applications

so it s quite close

in some way

DanielSank

It is rather close. We put our chips in an evacuated cryogenic chamber.

Bernard Meurer

@DanielSank Portuguese is enough trouble for me, let alone the German I was forced to learn. I've been considering using only grunts to prevent exhaustion from now on

DanielSank

20:07

In fact, our devices get considerably colder than space-bound devices :D

privetDruzia

I am reading your phd thesis right now, what advice would you give to someone whose dream is to pursue a PhD?

DanielSank

@BernardMeurer Heheh. Russian is wonderful, but don't ever try to express that you're going anywhere. The system of "motion" verbs is mind-boggling to say the least.

@privetDruzia You're reading my thesis?

Uh oh.

2

privetDruzia

yup

I am not a specialist, really. (Hence my questions about potential energy)

DanielSank

Ok, well, I'd like to ask you a small favor: if you find errors, please let me know.

privetDruzia

I am just very curious

DanielSank

20:08

I have a list of errata which I've been meaning to add.

I mean, I will actually fix the errors.

privetDruzia

hahahahah I will never find any, don't worry

DanielSank

oh ok

Bernard Meurer

@privetDruzia I've heard the first step to get a PhD is to give away your soul

privetDruzia

no problem, whenever u want

I am ready to do anything

FenderLesPaul

@ChrisWhite whaddup

dmckee

20:09

@DanielSank When I got the bound volumes back, I flipped one open to just marvel at this thing I had made.

DanielSank

@privetDruzia Advice? Well... if you want to do a PhD you basically have to pick a subject you like and study your ass off.

dmckee

And found a typo.

Arrrggggghhhhhhh!!!!!!!!!

DanielSank

@dmckee lolololol

That's why I never made any print copies.

privetDruzia

right now actually I am trying to find a way to publish a paper/abstract I wrote

related to space mechanics/engineering

DanielSank

I figured I'd let it go a year and see all the mistakes, fix them, and then do a pay-for-publish service thingy.

FenderLesPaul

20:10

I've always wanted to learn Russian

privetDruzia

pay-for publish?

DanielSank

@privetDruzia arXiv? Conference Proceedings?

FenderLesPaul

but it's very different from the languages I speak

privetDruzia

how much does it cost

?

FenderLesPaul

so I find it hard to learn

DanielSank

20:10

@privetDruzia You can send a pdf to some website and they mail you books.

dmckee

@DanielSank We were required to do five. Two for the library, and one for the department.

DanielSank

It's not super cheap.

dmckee

Apparently it was important that we own two bound copies ourselves.

DanielSank

@dmckee Oh yeah, I did those. Nobody will ever read them though ^^

dmckee

True, dat.

DanielSank

20:11

I even kept a signature page to use when I print my copy.

privetDruzia

conference: there are not that much conferences about the topic I am sudying
arXiv: I am having a look at it right now

DanielSank

@FenderLesPaul Yes, it's tricky. They do things that English and the Latin languages don't: noun declension.

privetDruzia

how does it work, do they keep sending u feedback so that u correct your paper and once it s good enough they publish it?

DanielSank

@privetDruzia Well, "they" are people I harass about giving me feedback.

privetDruzia

because you paid

mhm

DanielSank

20:12

@privetDruzia Oh no no no. You pay for the publishing, not editing.

yuggib

@0celo7 Urs Schreiber thinks that the cardinality of the reals is $\aleph_1$

privetDruzia

ok so it takes a lot of time before it gets published

DanielSank

If you want editing you'd have to pay an editor.

privetDruzia

oh even worse!

DanielSank

@privetDruzia It's up to you. I have been collecting feedback from my group members. I can buy hard copies whenever I want.

privetDruzia

20:13

so first you loose a lot of time waiting for them to find someone who is capable to give a good review/critics about your paper

FenderLesPaul

@DanielSank so I'm actually ok with noun declensions

DanielSank

@privetDruzia No no no.

FenderLesPaul

because I know Sanskrit and my first language is Hindi

privetDruzia

and then, as they ll always find something to say, you ll lose time correcting it etc...

FenderLesPaul

and Sanskrit does that as well

but for me Russian is really hard because of the verbs

also I can't pronounce shit haha

DanielSank

20:14

@privetDruzia I use my colleagues as editors. I wrote a lot of pedagogical stuff in my thesis: stuff that's very useful to graduate students. Therefore, I get a lot of feedback from them.

@FenderLesPaul Well, pronounciation is a personal issue. What's hard with the verbs for you? Is it the fact that there are so many irregular ones?

privetDruzia

ok and once you collegues tell it s ok, you send it to arXiv, so you don't waste any time?

DanielSank

Interestingly, Russian teachers like to claim that Russian doesn't have irregular verbs. "They all follow the rules, there are just a lot of rules".

privetDruzia

a lot of rules that just apply to one verb...

DanielSank

@privetDruzia For my thesis, I won't put it on arXiv. It's already on our group website so I don't really see a point of putting it on arXiv.

privetDruzia

like an irregular verb...

FenderLesPaul

20:15

@DanielSank yeah

DanielSank

Yeah what?

FenderLesPaul

the large amount of irregular verbs

makes it hard for me to learn it

languages are so much easier to learn in such cases when you're actually in an environment where it's used regularly

learning it in a class is just hard

privetDruzia

I am really new to al that stuff, it s been a month now I've been looking around on the internet (SE and reddit) for people willing and able to read my paper in order to receive some feedback. Found one person so far

What would be a good place for me to publish do you think?

(I ve heard researchgate is not OK)

DanielSank

@FenderLesPaul Yes absolutely.

As my Greek teacher said on the first day of class (which I missed): "There's only one reason to learn a language: love. Who is here for love reasons?"

FenderLesPaul

haha

DanielSank

20:18

I wasn't there, but I was dating a Greek at the time...

FenderLesPaul

I dated this girl who knew 4 languages

Chinese, French, Italian, and English

DanielSank

@privetDruzia I have no idea. What's the topic?

FenderLesPaul

it was one of the coolest set of skills I'd come across

DanielSank

@FenderLesPaul Yep, some people knew a lot of 'em.

FenderLesPaul

I wanna know more languages!

privetDruzia

20:19

attitude determination and control systems (for satellites)

DanielSank

My fiancee knows English, French, and and sort of do Italian.

@privetDruzia Surely there's a journal for such things.

FenderLesPaul

I took French for 6 years

and I still can't say anything

privetDruzia

how much time does it usually take between the first invoice of a paper and the publication?

DanielSank

Options:
1) Travel
2) Date someone who speaks it
3) Hang out with groups who speak it
4) Dedicate huge amounts of time in class

user54412

@FenderLesPaul spending the next 4-12 hours at the airport apparently

DanielSank

20:20

@privetDruzia There are no rules. It's entirely dependent on the field, the journal, and the content of the paper.

@ChrisWhite :(

FenderLesPaul

@ChrisWhite aww

DanielSank

@FenderLesPaul Wow, really? That must have been a crap class.

...or you don't like it?

privetDruzia

can it take a year or more? Or is this really exagerated?

FenderLesPaul

@DanielSank the teacher was just terrible

like wtf is this person doing terrible

DanielSank

@privetDruzia Again, it depends on the field, the journal, and the paper.

There are no rules.

It varies a lot.

privetDruzia

20:23

hmm ok so no certitudes anywhere

yuggib

@DanielSank in maths, a year would be short time

DanielSank

Correct.

privetDruzia

ok I ll continue looking and try to send my paper in a week or so

DanielSank

@yuggib wow

privetDruzia

tq)

yuggib

20:24

in math phys, we are more lucky and usually get away with 7/8 months on average

but once I got the paper refused after a year and a half with a crappy report

DanielSank

7/8 months is pretty long.

What journal are you thinking of?

yuggib

and a friend of mine in algebraic geometry got the paper refused after a year and a half because they couldn't find a referee @_@

ridicolous

ACuriousMind

@yuggib lolwut

That sounds as if he'd chosen the wrong journal

yuggib

believe me, it was one of the best math journals

and his paper was really good

ACuriousMind

Or is doing crazy stuff no one else understands...

user54412

20:28

@DanielSank the idea is that a math paper can be checked line by line for perfection, so they'll do just that.

DanielSank

@yuggib Wow, that's kind of funny.

@ChrisWhite Oh, we're talking math?

yuggib

@DanielSank the friend of mine didn't exactly used the words "funny"...

DanielSank

@yuggib Certainly not.

...but it is kind of funny...

yuggib

well, yes

more sort of ridicolous

user54412

Unlike experimental science where we can always retain doubt about the results anyway

user54412

20:32

Speaking of which a paper came out today that dedicated an entire appendix to refuting a paper of mine...

yuggib

nice guys...

DanielSank

@ChrisWhite If there's one thing I learned about academia/science in grad school, it's that when people get upset about your results it means you done good.

0celo7

20:50

@dmckee He apologized to the undergrads for his panicked emails. He won't be able to pay me for 2 weeks because he has to do the finances formally :/

But I do have a job now

dmckee

@0celo7 Well, that's something. The trick now is to figure out the summer. If your finances can stand it you might look seriously at the question of lab work for course credit.

0celo7

He said he can do 20 hours per week over the summer

But he said to look into a university funded research summer

Then I could get more hours during the spring

user116211

@Secret: well; I asked but the response was disaster:P So, you said, if I rewind at 50, the sequence would be 0 -10 -20 -30 -40 -50. Wouldn't that mean $v(50)= -v(0); v(40)= -v(-10)$ etcetera? But, I thought in time-reversal, $v(t)= -v(-t)$ that would mean $v(50)= -v(-50); v(40)= -v(-40)$, isn't it?

John Duffield

Can anybody give a succinct answer to this?

0

Q: What is a symplectic bundle?

AS THE TITLE SAYS: What is a symplectic bundle? I have googled this but only ended up with fiber bundles, but nothing was said about symplectic bundles? Those bundles appear when we deal with supergravity. Any intuitive answer is welcomed.

0celo7

21:07

@yuggib huh?

yuggib

he said that in a comment...

0celo7

is it wrong?

yuggib

let's say it is not right

0celo7

so what if he thinks the continuum hypothesis is right

he knows way more geometry/topology/etc. than you

notice "anal set theory" was not on my list of topics :)

Mike Miller

@JohnDuffield: Yes. Indeed, anybody could give a succinct answer to that.

guest

21:12

::makes popcorn::

yuggib

@0celo7 I am just saying that people doing geometry/topology/etc. should know set theory

John Duffield

@MikeMiller : please do before the question gets closed by a bunch of guys who can't.

Mike Miller

No, I'd rather see garbage questions closed.

0celo7

@MikeMiller so what is a symplectic bundle

John Duffield

@MikeMiller : bah, you can't answer it.

0celo7

21:13

bundle that is also a symplectic manifold?

Mike Miller

Without further context one would assume they mean to say symplectic vector bundle, which is a vector bundle in which each fiber has the structure of a symplectic vector space.

ACuriousMind

@0celo7 It's just a bundle that's fiberwise symplectic

0celo7

ah, ok

@yuggib is something like Arnold considered "mathematical physics"?

Mike Miller

There's not really a good reason to consider bundles of symplectic manifolds where the base has no extra structure.

ACuriousMind

@MikeMiller Doesn't mean physicists aren't doing it ;)

yuggib

21:17

@0celo7 in which sense?

0celo7

@yuggib the Italian sense

I'm just making a list of things I could possibly write a senior thesis on

Mike Miller

@ACuriousMind Why? In what context?

@yuggib: But the continuum hypothesis is more or less obviously true, my friend. :)

yuggib

yes, arnold is math phys

ACuriousMind

@MikeMiller Well, I don't know. I just meant I wouldn't exclude it.

yuggib

@MikeMiller many contemporary logicians consider it obviously false

:-)

0celo7

21:19

oh, they have a counterexample?

ACuriousMind

Logicians have a concept of "obvious"? oO

yuggib

ahahah apparently

0celo7

if it hasn't been proven, it's obviously false

yuggib

sadly, I don't remember in which book I read it

0celo7

once it has been proven, it's obviously true

Mike Miller

21:20

@yuggib Yes, but I am not a contemporary logician!

yuggib

it has been proven to be independent of ZFC

ACuriousMind

You're...a logician from the future?

Mike Miller

Therefore, because contemporarly logicians consider it obviously false, I consider it obviously true.

yuggib

@MikeMiller why?

what's your intuition?

I am genuinely curious

Mike Miller

That sentence was a joke, since one doesn't follow from the other.

0celo7

21:21

obviously $\mathbb{R}-\{0\}$ has cardinality $\omega-1$

yuggib

@0celo7 $\omega -1$ is not a cardinal ;-)

0celo7

@yuggib proof?

Mike Miller

In any case, I don't have any. I'm just being pointlessly contrarian.

It's great fun.

yuggib

@MikeMiller :-D

0celo7

when I do that I just get called a "troll"

Mike Miller

21:23

Alternatively: "Every second-countable manifold is either countable or cardinality $\Bbb R$. Everything that exists is a second-countable manifold. Therefore..."

0celo7

@ACuriousMind ugh one of your countrymen was supposed to send me an email

actually, two were

Germany is going down the Klo

no reliability anymore

yuggib

@0celo7 sum of ordinals or cardinals is defined, but not their difference afaik

but $\omega -1$ should be defined in surreal numbers

0celo7

@yuggib fine then $\omega+(-1)$

yuggib

@0celo7 $-1$ is neither an ordinal nor a cardinal

0celo7

ordinal is?

ACuriousMind

21:25

@0celo7 Maybe they were exiled from the fatherland because they aren't punctual enough to be true Germans :P

yuggib

sets that take ordering into account

0celo7

@ACuriousMind there's another German prof and he does functional analysis/operator theory

he might just be pedantic enough to write on time...

GBeau

@FenderLesPaul Michigan Ann Arbor, says email date was Jan 13

0celo7

I could have told you that

@yuggib wat

yuggib

ordinals are numbers that represent set together with their (well) order

so they're much more than the cardinals

FenderLesPaul

21:46

@GBeau oh that's the early admission one

anything for regular admission?

GBeau

@FenderLesPaul no I mean an additional one was added, today, that was dated from then

FenderLesPaul

right

but like any email sent out today for UMich?

GBeau

@FenderLesPaul the forum has one on Jan 21

FenderLesPaul

yeah I noticed that one

GBeau

@FenderLesPaul and an interview Jan 22

FenderLesPaul

21:49

yeah my friend also got an interview from UCSB

apparently it was mainly just to gauge how well they knew their own research

his is in AMO

Mike Miller

ams.org/mathscinet-getitem?mr=MR0154641

GBeau

I'm dreading possibility of an interview

not that I don't think I could do well, but like

that's so much pressure

k,,,,,lop90-

FenderLesPaul

:p

I'll take anything over silence haha

yuggib

@MikeMiller why?

Mike Miller

@yuggib Does it show the review or just the article title? The review is amusing.

yuggib

22:01

I have subscription

yeah it's amusing

Mike Miller

Similarly, though not physics

yuggib

I am surprised that cahiers de physique is indexed by mathscinet

:-D

I have to say that I am less caustic in my mathscinet reviews

also, I have not been assigned very shitty papers yet

Mike Miller

I tend to believe that such harsh reviews are not common.

source

yuggib

:-D

one of the infamous authors is from my alma mater

he did not have a very good reputation also there to be honest

Mike Miller

What do you study?

(Completely unrelated to previous discussion.)

yuggib

22:09

math phys/analysis

Mike Miller

More specifically?

yuggib

semiclassical analysis for infinite dimensional systems

non-linear systems of PDEs (but not too difficult stuff)

self-adjointness problems

Mike Miller

Ok, now I sort of understandish.

GBeau

@FenderLesPaul places that sent out on tomorrow, last year: UC SD, UC SB,

0celo7

@yuggib does it give you the paper too?

FenderLesPaul

22:17

@GBeau I've given up on UCSB I don't stand a chance

no amount of connections will help me haha

yuggib

@0celo7 no, it's too old and who knows the journal how ended up

0celo7

oh ok

I see the review too

GBeau

@FenderLesPaul so far schools have shown (overall, for the most part), consistent dates with when they sent out last year, down to the exact day

@FenderLesPaul but I have to convert the day to align to the day of the week, not the day of the month

so, Jan 27th last year is Jan 26th this year, because Jan 27th last year was Tuesday, and tomorrow, the 26th, is tuesday

and that conversion has been pretty accurate as far as predicting dates

FenderLesPaul

fuck I have to give a talk tomorrow haha

worst day to send out emails

GBeau

@FenderLesPaul Thursday the flood begins and doesn't stop until the season ends

FenderLesPaul

22:27

yeah

what does your methodology give for MIT?

0celo7

@ACuriousMind still no email .-.

"I'll email you the paper right away"

3 hours later...

ACuriousMind

"right away" from a prof means "if I remember" :P

0celo7

I have to give a summary of it in the next group meeting D:

0celo7

22:59

@ACuriousMind what's an appropriate amount of time before I remind him

ACuriousMind

@0celo7 I'd say that depends on when the next meeting is

FenderLesPaul

omg Joan Baez is coming here

in a couple of months

so excited

ACuriousMind

I have no idea who that is

Unless you mistyped and meant John Baez, the mathematical physicist :P

FenderLesPaul

no Joan Baez, she's a legendary folk artist

she's John Baez's cousin

ironically he's the unknown one compared to her

0celo7

@ACuriousMind Montag

ACuriousMind

23:12

then I'd wait till tomorrow at least, I think

GBeau

@FenderLesPaul 100 hours

until 5 pm west coast friday

DanielSank

23:39

Hi, everybody.

0celo7

@DanielSank hello

DanielSank

I'm reading your thing again.

FenderLesPaul

@GBeau for MIT?

GBeau

@FenderLesPaul no, until 5 pm on the west coast on friday

FenderLesPaul

ohh

do you know when MIT typically sends out stuff though?

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