i never like any of weird al's parody songs

Let me just google masala rice ...

@BalarkaSen Me neither

Hmm, looks like a pilaf to me

They just seem... average and way too musical with not very interesting parody content.

@Kaumudi.H Learn how to make kitchuri rice - it's delicious!

my favorite satirical musician is tom lehrer but of course he's a god

And nutritious.

4. claim it was all your own work :-)

Ooh, potato rice

@JohnRennie Should I care about my exams even if I am transferring and they will have no further importance whatsoever?

@BernardoMeurer Yes, caring is what makes us cool dudes not scrubs

@JohnRennie But I am a scrub :P

It's your self respect at stake!!

I have no self respect

What are you talking about?

When you transfer to SB how do they determine your final grade when you graduate? Do they take into account your first year grade at the previous university or are you starting from scratch?

@JohnRennie I'm starting from scratch

I could transfer credits but I'm not interested

I want to retake the classes to get better grades

So do you have to do the full course - another 4 years?

Yep

So I basically wasted one year here

Well, not fully wasted, I learned a lot

But it won't be on my curriculum

But I'm okay with this because I'm young still

@BernardoMeurer I was about to say it wasn't wasted :-)

a waste of money :P

@user685272 True dat

everything is a waste ultimately

@BalarkaSen Oh shut up

:P

Define: waste

Hi @Semiclassical welcome :-)

@JohnRennie My point is: I have 5 subjects this semester: Computer Architecture, Programming, Mulivariable Real Analysis, Mechanics and Waves, Management

I have already passed Computer Architecture and Programming

I don't even have to go to my final and I will still pass

Management is ez, so I'll figure it out

Now, Mechanics and Analysis is a whole other deal, I am SCREWED in those

I'd have to go full crazy like I did last semester now to even stand a chance at passing

But I question: Is it worth it?

Learning to "go full crazy" is a useful skill, I guess.

In the short term.

@BernardoMeurer Yes

I just don't want to go super sayan for a month again. Last time I ended up depressed, overweight, and exhausted

@JohnRennie Hmhmm

That's what we do

Then, learn from your mistakes

as well as your successes

Do whatever that makes you happy. If you feel the need to learn multivariable real analysis, learn and not for the finals because they don't matter (that's what I extract from your comments).

If you don't, whateva

@JohnRennie You are right, that is what we do

But this being my suggestion, hear this with caution even though I do not suggest with caution

eh. Do whatever will make you happy works once you've done enough other stuff to survive.

^

apparently he'll survive if he fails the other two exams

so

I could fail all my exams and it wouldn't matter

curriculum-wise

anyway I think it's common human right to continue proceeding along the path of fiery death and destruction if he feels happy about that

so i won't argue

@BalarkaSen What do you mean?

@MetaEd Howdy

@BernardoMeurer Howdy yerself!

Welcome :-)

@BernardoMeurer Then you should just take it easy on multicalc. Learn whatever that makes you feel like learning it. Do you have any interest at all about this stuff?

You might end up learning more if you don't exhaust yourself down for a month on that exam.

@BalarkaSen I hate analysis with a passion, I really, really hate it

It's the thing I least like studying after Chemistry

(My fiery death and destruction comment was a reply to SemiC, not you)

@BernardoMeurer The most painful part of retaking a course is attending the lectures again.

What is on your syllabi

@BalarkaSen Oh boy brace yourself

Topology and continuity in Rn, Differential calculus in Rn, Taylor series and extrema, Multiple integration, Inverse and implicit function theorems, Differentiable manifolds, Integration in scalar fields on manifolds, line integrals in vector fields, Integrating on vector fields over manifolds

That's pretty hardcore. That's more than I did in first year mathematical methods for physicists.

That's one goddamn semester

Sounds more like a course for 2nd year mathematics majors.

Or extremely clever 1st years

I'm a first year computer engineer

Yeah, I know.

@BernardoMeurer ^

here is a lecture series I like, if it helps. It covers more than what's in your syllabus and more rigorously but he does lots and lots of examples

maybe casually look at whatever

@BalarkaSen Nice! Thanks!

Wait, they do it in two semesters?

That's not fair!

:P

Ted also has a book, but it's expensive and does not exist on internet. Maybe you can find it in your university library or something. It's where I learnt multicalc.

@BernardoMeurer You people do it in one semester?

Yes

That's too much.

@BalarkaSen What's the name of the book?

We do all of that I mentioned here in a single semester

Even though the rigor level of your course is probably not of Ted's course.

It's bananas, it's just too much stuff

"Mutivariable Mathematics: Linear Algebra, Multivariable Calculus and Manifolds"

It's the only true book on multivariable calculus I actively like.

Holy cow, 200 bucks

Yeah, nope

it is expensive

@BernardoMeurer Ask him here to give you a free copy:

Not a great idea.

@Mostafa That's not respectful to his work IMO

@JohnRennie Okay, here is my conclusion

I cannot aptly manage my time to pass both physics and analysis

If it's first year it probably means like Thomas or Stewart calculus and is just using the word manifold?

However, my Physics professor is literally the worst professor I have had in my life, while the analysis one is quite good

So I will focus on passing analysis, in respect to the good prof

Lots of good videos online man

Those Shifrin videos are good

if you need any help let me know

@bolbteppa My bibliography is spivak's calculus on manifolds

@BalarkaSen Thanks man :)

For first year comp sci/eng maths???

@BernardoMeurer Go, go, go!

And Vector Calculus by Marsden, Tromba, Freeman

@bolbteppa My university is crazy man

and I do CEng, not CS

@JohnRennie Sounds reasonable?

Slow editing

@bolbteppa But yea, this is first year, lol

Yeah it looks more like Marsden since it has Taylor expansions and stuff

@BernardoMeurer yes, that seems like a good option. Those math skills will serve you well in the future.

@JohnRennie I will just cover the physics syllabus with Daniel once I'm in SB :P

Cool guys! I'll order a pizza to celebrate

@BalarkaSen For starters I get really confused when changing order of integration/ fubini's theorem

@Bernardo Ah?

What is it that confuses you?

@ACuriousMind why do we not consider compactification on a torus anyway

Is it because we tried and the mass scale is wrong?

@Slereah Well, you can compactify on a torus. The result looks nothing like the standard model, though

And the main aim of string phenomenology is to understand compactifications that produce the features of the Standard Model like (Chiral) fermions or (non-Abelian) gauge fields

Too bad

What does string theory look like on the torus

Is it anything familiar?

Well, it just gives a very boring and plain SUGRA in 4d, I think

Although you do get string effects - at special values of the radii, you should see an enhancement of the gauge symmetry to SU(2), I guess

Is bosonic string theory even very hard to solve?

What does it mean to "solve" it?

It's free CFTs on a Riemannian 2 manifold

That's almost the simplest possible thing

@Slereah No, it's not. The string partition function crucially is not the partition function of any single CFT.

You can say that there are CFTs living on the worldsheet, but string theory is not a QFT

How do you compute quantities, then?

What quantities?

The scattering amplitudes are given by the string partition function/S-matrix with the appropriate vertex operators inserted

You could conceivably insert other operators to get their expectation values

Isn't that just a path integral of riemannian cfts?

@Slereah No, the sum over worldsheet topologies is something you will not see in any CFT

Well yeah but individually, a single topology is a CFT, right?

Yes, the individual terms are basically the expectation values of the vertex operators in the respective CFT

I guess the hard part might be the interpolating topology between strings

There's a lot of them

I'm reasonably sure these amplitudes have been computed to a few orders somewhere

Probably yeah

Riemannian 2D has a lot of nice features

But at some point, computing higher orders of something you do not expect to have anything to do with something observable becomes pretty pointless

For spinors, if you begin from a quadratic form $Q(x,x) = \eta_{\mu \mu} x^{\mu} x^{\mu}$ over $\mathbb{R}$ and try to factor it as the square of a linear form, $\eta_{\mu \mu} x^{\mu} x^{\mu} = (p_{\mu} x^{\mu})^2$, both $p_{\mu} x^{\mu}$ and $- p_{\mu} x^{\mu}$ could have been used, similarly over $\mathbb{C}$ we could have scaled it by $e^{i\theta}$, I guess this links to projective representations?

@Slereah Did you see my email dawg?

Yeah

I'll look into it this week end

@Slereah God bless your beautiful french soul

Who's the crazy man starring everything

@JohnDuffield Hello darkness my old friend

What say hbar?

physics.stackexchange.com/review/suggested-edits/178701

Insignificant improvement isn't an option.

@TheDarkSide 1. We do not reject edits for being "too minor" anymore. 2. Even if we did, I consider proper spelling of multiple words not insignificant.

@ACuriousMind That's what I wanted to check.

@TheDarkSide The worry about insignificant edits has always been that authors can use them to bump their post and get unfair attention. I've never been convinced this was an issue, and in this case it isn't the author doing the editing.

If someone has taken the time and trouble to go through a post and tidy it up, even if it's only minor tidying, it seems churlish to reject their edit.

I don't disagree with that.

But there is a +2 for a suggested edit below 2k rep.

I think people should earn that +2.

Shrug :-)

Well, we can disagree on certain things.

Are people really that desperate for rep that they'd be willing to edit a thousand questions to reach the lofty heights of 2K rep? :-)

You can only get 1k rep total from editing, iirc

@JohnRennie Can't comment on specific cases, but I'll reason as follows:

@TheDarkSide Considering how easy it is to write completely wrong answers that look authoritative and earn some upvotes, people farming rep through well-intentioned copy editing does not strike me as something we should prevent

Certain features, participating in chat, commenting etc. have a certain (small) rep requirement, which exists by design.

There are multiple ways of getting over it.

This is an easier alternative.

@ACuriousMind So, back to square 1, why did we have the "too minor" option earlier?

@TheDarkSide for fear that authors would abuse it to bump their posts.

@JohnRennie We (the mods) see it once or twice a year, so I wouldn't call it a big problem. At least half of the time a quite word suggesting they do fewer more comprehensive edits is enough.

@JohnRennie There are multiple ways of going around that anyways. We can have well-intended multiple edits after every 1 hr or so. That'll do the job.

Also, how about socks?

@JohnRennie author edits to their own posts were never reviewed in the first place

(Responding in general, not a specific accusation.)

:: Assuming good intentions ::

@TheDarkSide That's what I would call a 'blue pencil' edit, but he's taken care a a bunch of minor problems at once so I consider it a nicely done job.

@TheDarkSide Well, because we didn't want to bump posts just for a single apostrophe or the like. I wouldn't have rejected this edit as too minor even back then

@dmckee and @ACuriousMind - Yes, I concur that this case is borderline even by some stringent criteria. That's why I consulted before doing anything with it.

And missed the bus in the process

:)

@ACuriousMind Do author edits to their own posts bump the question? If so I should start leaving deliberate typos in my answers :-)

@JohnRennie Yes :P

@JohnRennie I think yes.

I'll remember that for the next time I answer a question on generic relativity

I find it strange that there are still hidden easter eggs for you on PSE !!

@TheDarkSide you overestimate the degree to which I care :-)

@JohnRennie :)

I think the vast majority of contributors here do so in good faith, so I'm not too fussed about the very few takers of the piss.

@JohnRennie I was curious, did you ever get a resolution to the energy question re: de Sitter space you had yesterday? (not that I'm not in a position to understand the answe)

@Semiclassical No.

mmkay.

I suspect it's all down to what you mean by energy.

Would not surprise me.

With that metric there appears to be a potential energy much like a gravitational potential energy, and I think that makes the total energy constant.

The physical meaning of the apparent potential energy is somewhat dubious, but as I say it depends on what you label as energy.

Right.

Alas, this is a problem where I can't do much more than smile and nod :/

But thanks for filling me in.

Our GR experts tend not to visit the chat room, and I'm not sure I can make the question coherent enough to post on the main site. Maybe I'll try to make it a bit more focussed and post it.

sure.

My knowledge of GR caps out at the conceptual level, which is a pretty low bar.

(I went down the condensed matter route, which doesn't really care about GR)

@JohnRennie According to data, the highest number of the suggested edits for a user is 417.

Are you calling me not a GR expert

Also, @TheDarkSide ranks rather high (18th) on the list ;)

@Slereah well you haven't answered my question :-)

You don't appear on the top 20 list of GR answerers, though you are at number 9 of the GR askers.

I'm not very high on the list of gets answers to his GR questions!

Bonjour.

What's your opinion of Penrose's latest book? @Slereah

Which one

Is it another crazy book

About quantum consciousness

The one you ordered.

I haven't ordered any Penrose book recently

I was thinking about developing an app to determine whether a watermelon is good or not based on analyzing the sound it makes when tapped...turned out there's already one:

play.google.com/store/apps/…

I don't know how it works though

I read iOS 10 is coming out soon

deepak chopra with quantum healing tho

@JohnRennie The only thing that I could think of is that it's got something to do with an implicit 'some of the co-ordinates are functions of time' or something, but that's one of those extremely wild guess moments

Hi!

When minimizing a function of the form $f(\vec{x}) = \frac{1}{2} \| \vec{r(x)} \|^2_2, \quad \vec{r(x)} \in \mathbb{R}^m$, the $\frac{1}{2}$ is put in front of the function because if we derive $\| \vec{r(x)} \|^2_2$ a $2$ comes down and cancels the $\frac{1}{2}$, right?

@Mostafa Negative charges go from low to high potentials because the electric field is defined wrt positive charges.

So yeah, the suggested edit is wrong.

@JaimeGallego I rejected it but someone who seems to be a more knowledgeable physicist than me had it approved :)

Oh well, anyone can be mistaken from time to time.

well, it's been rejected now :)

(not me - I don't have the rep :P )

Does it really work? ^

It works for my cat

You can also place documents nearby, and it's guaranteed they will sit on them provided they're important enough.

$P(\text{cat ignoring document}) \propto \frac{1}{\text{Importance of document}}$

That's a lousy equation tho, k times the right side can't exceed 1.

@JaimeGallego very interesting!

@JaimeGallego if $\text{importance of document}$ belongs to $\mathbb{R}_{>0}$ you can't find a coefficient that keeps $P \leq 1$ for all $\text{importance of document}$s.

How are you gonna deal with that?

It's similar to a non-normalizable state. Maybe others who know more QM can help

$P(ignore) = \frac{1}{1+e^{x-5}}$ with $x \in [0, 10]$

Good old logistic functions

Plus it defines more realistic behavior, some do sit on worthless papers :P

@Mostafa When the cat got into a box, we used to grab a marker, scribble "I am homeless, please give me food" on a paper, and put the sign in front of her

$P(\text{dead chat}) \rightarrow 1$