The h Bar

Anonymous

12:04

Anonymous

Oh, now I understand :P

Balarka Sen

Right, that's it.

Anonymous

Thanks @BalarkaSen Wiki has a habit of making easy things look difficult :P

Slereah

Is there a specific name for the Lagrangian of a point particle

Balarka Sen

When I use the bumblebee analogy, I am thinking of particles moving along curves ("1 dimensional manifolds") in R^3. But note that you could think about particles moving along surfaces("2 dimensional manifolds") in R^3 too, like constraining an electron to move along a charged plate or something, maybe.

Slereah

12:06

In the same way as the Nambu-Goto action for strings

Anonymous

@BalarkaSen Yup, gotcha!

Balarka Sen

Basically think of all of this as a particle constrained (by some forces imposed on it, like you'd do it to keep electrons on a charged plate from not escaping from it) to move along it's trajectory (can be a curve, can be a surface), and the virtual displacement is the tangent vector to the curve/surface inherent to the curve/surface, coming from the constraint forces, independent of time.

This is basically what wikipedia wants to say.

Anonymous

@BalarkaSen Yes, as the trajectory would be independent of time.

Anonymous

I get it now :)

Balarka Sen

Okizay

Anonymous

12:10

For example the normal force would always be perpendicular to the tangent vector and the virtual work done would be 0

Anonymous

Thanks!

Balarka Sen

Yeah that sounds right.

some of physics is just mathematics with nonstandard terminology lol

and the rest of it is nonsense

Anonymous

@BalarkaSen well, be ready to be attacked by physicists now :D

Balarka Sen

Oh, this is the hbar not mathematics. Shit.

Anonymous

lol :D

Mithrandir24601

12:14

Yeah, I mean - if you think that the physics which isn't maths is nonsense, why are you on physics SE? :P

Secret

Don't worry, I am (half) a mathematician here lolollol

Specifically, I don't like hand waving problem solving unless I understood the method

Balarka Sen

@Mithrandir24601 I am here to chew bubblegum and kick ass. And I'm all outta bubblegum

Mithrandir24601

@BalarkaSen pulls out sword

user228700

@BalarkaSen Okizay? O.O

Balarka Sen

I'd give anything to exchange any action film for They Live, especially Kill Bill.

Mithrandir24601

12:30

Although I think I actually prefer this one or even this one. I'd better stop now before I waste my Saturday afternoon :P

user228700

Stupid coaching institutions. It's been a whole year and they're still sending me messages about JEE -_-

user228700

Hey @BernardoMeurer! :-) How'd the exam go?

Balarka Sen

i like those marshal arts fight sequences but absolutely nothing beats this

i think it's well recognized as one of the best fight sequences of the century

Anonymous

@BalarkaSen Nothing beats this (Caution: Watch it at your own risk :P)

PhyMan

@blue Exactly ;))

Everythings gone bananas

user228700

12:36

Is that the one with the banana gun?

PhyMan

yup

user228700

x'D A Telugu film, I see.

user228700

Haven't had anybody native to Telengana or A.P here... yet.

Balarka Sen

I am not watching that.

Mithrandir24601

@BalarkaSen I don't think I get the context to really appreciate it :/

user228700

12:39

@Avantgarde: I find myself disagreeing with something I said before:

user228700

May 13 at 5:33, by Kaumudi. H

@Avantgarde It's nice to look at pretty clothes but I can only handle it for about 5 minutes before I get really tired of walking around...on and on and on.

user228700

Nope. Even looking and deciding is exhausting.

Balarka Sen

@Mithrandir I recommend the film. Everybody should see it.

It's weird without the context, yeah. Two men fight themselves off like packs of dogs on urban lanes for some stereotypical goggles lol

Carpenter is a genius man

Mithrandir24601

@BalarkaSen Added to the list :)

Thanks

And now I'm off to get lunch...

user228700

Ugh, it really sucks that there isn't more than one girl around here more often.

user228700

12:43

Do people shop for a living? Is that a job? Shopping for people?

user228700

K thx (for ur wonderful responses) bai.

Balarka Sen

I don't like people.

I wanted to put that in scare quotes but I don't think I will.

PhyMan

@Kaumudi.H Yeah, I think so.... people may be shopping for others

Anonymous

@Kaumudi.H Isn't that what Flipkart/Amazon and other e-stores effectively do?

user228700

@BalarkaSen Yeah, no, I know :-P You've mentioned that before.

user228700

12:50

@blue No, they're online stores. I was wondering about people shopping for other people. I wasn't really wondering though; I was just frustrated at all this shopping I gotta do and was trying to vent that here but oh, well.

user228700

@PhyMan Worst. Job. Ever.

Anonymous

@Kaumudi.H Ugh, even I hate shopping at stores. I order everything online nowadays except when going out for dinner/lunch :P

Sid

@Kaumudi.H Easy. Get someone else to do your shopping.

Yeah, online shopping is easier.

user228700

@blue No, no, I find myself hating even online shopping!!!

Anonymous

@BalarkaSen That's similar to saying "I don't like water" :D

Sanya

12:53

@BalarkaSen that's very reasonable :)

user228700

Someone save me.

Balarka Sen

It's a false conclusion to believe I have mentioned it before. If I said that 2 months ago, that was out of a misplaced sense of misanthropy. What I said now is deeply influenced by the public works of Puncher and Wattman on existentialism and of their interpretation of an unearhtly being "God".

Even if I say the same things, they are different things the moment I say it.

user228700

@BalarkaSen ...that, wow, that is so true.

Balarka Sen

lol

Anonymous

12:54

@Kaumudi.H Pay me Rs. 10,000. I'll do the shopping for you. :P

Balarka Sen

I was just trolling

user228700

@BalarkaSen It's still true though, what u said.

Sid

@blue I didn't get that much money even by selling my books..

user228700

@blue Gosh, 10,000? Boi, if I had that much money, I wouldn't even be shopping right now, I'd be in effing Darjeeling.

Balarka Sen

Read "Pierre Menard, author of quixote" by Borges if you want to see similar ideas exploited in a fantastique fashion.

@blue yeh, and i'm fine without water

user228700

12:57

^ Sigh, one can never take u too seriously.

Mostafa

@JaimeGallego He seems to be alive

Sid

@Mostafa So, basically you are saying that people in London should go about searching for a guy to make him accept an answer in Tex.SE?

bolbteppa

Never understood the virtual displacement stuff, seems like 19'th century way of talking about moving between paths in a functional

user228700

YES YES YES (sorry for spamming but) YES Awesome_Tyme liked and replied to me tweet!

Ben Niehoff

amazing! It's still more or less the same people here!

Mostafa

12:59

@Sid That seems to be a serious concern of TeX.SE users

bolbteppa

Been gone for like 2 months mostly :p

Ben Niehoff

I've also been gone for at least 2 months :P

Balarka Sen

@BenNiehoff The entropy has increased, I suspect, though. Give it another 2 billion years and this would evolve into 4chan /b/

Ben Niehoff

does 4chan have a physics board?

Balarka Sen

I dunno

Slereah

13:01

It has a science board

/sci/

Mostafa

Did you guys know that men's life expectancy is around 7 years shorter than women's, yet men only receive 35% of health care and medical funding?

Sanya

@bolbteppa you usually try teaching classical mechanics to undergrads who struggle with differential equations ... so, it's a good idea not to go into functionals yet I think

Sid

@Mostafa Gender Discrimination!

Ben Niehoff

@Mostafa there is way more to healthcare than life expectancy

bolbteppa

I think 19'th century virtual work etc is far more confusing than a function of functions

Balarka Sen

13:02

I expect to die next Friday.

With a high probability.

Sid

@BalarkaSen Yeah, lack of water is fatal.

Mostafa

@BalarkaSen WHY

Anonymous

@BalarkaSen next Friday never comes

Sanya

@bolbteppa I have found a lot of people to be much more susceptible to esoteric explanations than to decent math, so it might be a question of perspective ... :D

bolbteppa

Heh I guess so

Anonymous

13:04

@Mostafa Women are considered to be "fragile"......(Nothing could be farther from the truth though :P)

Balarka Sen

@bolbteppa A virtual displacement is clearly simply a derivation on the tangent bundle of a differential 2-topoi.

Bernardo Meurer

@Kaumudi.H It was super hard!

3 hour exam, over 20 questions!

I wrote >20 pages

Mostafa

@blue Yeah, unfortunately. For example, men account for the majority of workplace injuries and fatalities (93%) because men are more likely to work in hazardous conditions.

bolbteppa

You can get from $F = ma$ to $F - ma = 0$ and then you can dot this with $dr$ to get $(F - ma).dr = 0$ and from this derive the Lagrangian, I think $dr$ is supposed to be a virtual displacement if you take this perspective, and you're supposed to give some hand-waving interpretation of it, but we all know it in terms of functionals naturally :p

Balarka Sen

Expect over 9000 on math, @Bernardo. How did it go?

Bernardo Meurer

13:06

@BalarkaSen I think I did okay, but I couldn't remember the argument-syntax for fgets or strtok so I couldn't solve that question

Because I use getline and strsep on my code because it's more modern and doesn't explode your computer if you screw up

Mostafa

@blue and also when a country is at war, men are usually expected to be soldiers

Balarka Sen

Fair enough. You're probably going to do just fine.

Bernardo Meurer

It's a bit silly that they expect you to know these things by heart on a written exam :/

bolbteppa

@BenNiehoff have you ever asked yourself why you can't just take a normal covariant derivative of a spinor, $\nabla \psi_{\nu} = (\partial_{\mu} \psi_{\nu} + \Gamma_{\mu \nu}^{\rho} \psi_{\rho})$?

Mostafa

All these happen while, for example, women are the initiators of domestic violence in 58% of all cases, and cause physical abuse in almost 50% of all cases, yet women only account for 6% of all criminal proceedings in such matters. @blue

bolbteppa

13:10

D'Alembert's principle

D'Alembert's principle, also known as the Lagrange–d'Alembert principle, is a statement of the fundamental classical laws of motion. It is named after its discoverer, the French physicist and mathematician Jean le Rond d'Alembert. It is the dynamic analogue to the principle of virtual work for applied forces in a static system and in fact is more general than Hamilton's principle, avoiding restriction to holonomic systems. A holonomic constraint depends only on the coordinates and time. It does not depend on the velocities. If the negative terms in accelerations are recognized as inertial forces...

Balarka Sen

eek I have to work

Sanya

@BalarkaSen yuck, on a saturday?

Anonymous

@Mostafa People would counter you by saying that during childbirth you would have to bear the pain of bones being crushed/broken...although that has been radically reduced by the discovery of C-section surgery. Anyhow, we nothing's gonna change till people become aware of the facts and the myths.

Ben Niehoff

@bolbteppa I'm not sure what you're asking...of course you can take spinor covariant derivatives, but you need the appropriate quantities defined in the spin bundle

Anonymous

@Mostafa Oh, I didn't know those percentages before. Hmm.

bolbteppa

13:13

In GSW they give this discussion of why you need spin bundles basicallly mathoverflow.net/q/121620/38721

Trying to flesh out the proof has taken days :p

Ben Niehoff

well, where else is a spinor to live, if not a spin bundle?

bolbteppa

If you could reduce reps of $GL(V)$ to reps of spinors then you could just take it's covariant derivative the way you'd do with a vector field, the inability to do this is why you can't just do that and why you need spin bundles, because you can't associate the connection coefficients to a spinor due the whole 2-1 nature

user685272

Welcome back @BenNiehoff nice to see you :-)

Ben Niehoff

It seems a bit bizarre to obsess over GL(N), since in physics we always work with manifolds equipped with a (pseudo)-Riemannian metric, and thus with structure group O(p,q), which always has spin representations

bolbteppa

They say "The most elementary formulas of gr for coupling of gravity to matter fields require that the matter fields form representations of $GL(V)$" so you basically have to end up doing this somehow (via local lorentz transforms)

Ben Niehoff

13:20

Of course, we often ignore the necessary detail that our manifolds be spin; I've only ever seen one paper that looks into this on some specific SUGRA solutions in order to conclude something useful about them

"local Lorentz transformations" are precisely the O(n-1,1) that I was just referring to

bolbteppa

Yeah

Ben Niehoff

I'm not sure what to make of matter fields being in irreps in GR...they must mean locally

because you don't have to have any linear global symmetries at all

bolbteppa

So far I've found a paper which cites this section as having already made an erroneous statement commonly cited in GR literature (but mostly correct), and that is another good point, what do they mean about irreps

Ben Niehoff

I mean, it sounds like they're trying to say "matter fields in GR are tensors" in some fancier-sounding way

except, of course, for the matter fields which are spinor-tensors :D

bolbteppa

haha

Ben Niehoff

13:28

yeah, that sounds like pretty backwards reasoning, to me

like saying that the desire to put spinors on a manifold requires that we impose a metric

in any case, they're only talking about linear transformations at a point

heather

@DanielSank lol, that's awesome

bolbteppa

I'm sure there's a safe way to say what they're saying :p

Ben Niehoff

I mean, to me it really sounds like they're saying "We'd like to put spinors on our manifold...and look, hey, this requires that we introduce the vielbein!"

which in fact is necessary, but not sufficient, as you also need to have a spin structure

bolbteppa

It's interesting that if you blindly take a partial derivative of a vector, but make it's basis local, you derive the existence connection coefficients without knowing any differential geometry
\begin{align}
\partial_{\nu} \mathbf{A} &= \partial_{\nu} (A^{\mu} \mathbf{e}_{\mu} ) = \partial_{\nu} A^{\mu} \mathbf{e}_{\mu} + A^{\mu} \partial_{\nu} \mathbf{e}_{\mu} = \partial_{\nu} A^{\mu} \mathbf{e}_{\mu} + A^{\mu} \Gamma_{\nu \mu}^{\rho} \mathbf{e}_{\rho} = (\partial_{\nu} A^{\mu} + A^{\rho} \Gamma_{\nu \rho}^{\mu})\mathbf{e}_{\mu}, \\

If you then simply apply this derivative to a spinor without deriving it you apparently get a contradiction

ACuriousMind

Great, my parents called while I was eating cereal and now it's all soggy :'(

Ben Niehoff

13:36

@bolbteppa I don't see why you would expect that derivative to apply to spinors anyway

bolbteppa

Which is stated in this theorem (which GR books have cited incorrectly for 50 years apparently)
https://i.sstatic.net/U0yXH.png

Ben Niehoff

earlier you gave a spinor with a spacetime index, which is actually a spinor-vector (a spin-3/2 object)

bolbteppa

Basically, if you be a dumb physicist and just apply random derivatives to random things you can derive the contradiction :p

Ben Niehoff

but let me just give you a plain spinor: $\epsilon$. What would you expect to work here?

bolbteppa

But

The cool thing

The very cool thing

If you copy the derivation of the covariant derivative I gave above including gamma's you get the spin covariant derivative:

physicsoverflow.org/31715/…

Ben Niehoff

13:38

@bolbteppa I don't understand this "theorem"...it seems to be obviously false.

bolbteppa

In the first answer to that question

This was stated in the 50's before spin connections so I guess it should be stated by specifying which connection they're using?

Sanya

@ACuriousMind should've continued to eat :o

bolbteppa

It's right in some context, this stuff is mind numbing at times tbh

ACuriousMind

@Sanya I definitely should.

Sanya

@ACuriousMind it's cereals after all and I think your parents could have taken it :D but maybe, if you mix in more cereals, the crispiness comes back?

bolbteppa

13:46

\begin{align}
\partial_{\mu} \gamma^{\mu} \psi &= \delta_{\mu}^{\nu} \partial_{\nu} (\gamma^{\mu} \psi) = \delta_{\mu}^{\nu} [\gamma^{\mu} \partial_{\nu} \psi + \partial_{\nu} \gamma^{\mu} \psi ] = \delta_{\mu}^{\nu} [\gamma^{\mu} \partial_{\nu} \psi + \omega_{\nu \rho}^{\mu} \gamma^{\rho} \psi ], \\
D_{\nu} \psi &= \gamma^{\mu} \partial_{\nu} \psi + \omega_{\nu \rho}^{\mu} \gamma^{\rho} \psi .
\end{align}

This GSW thing is just so confusing I should just skip it at this stage

Ben Niehoff

I mean, the spinor covariant derivative is $\nabla_\mu \epsilon = \partial_\mu \epsilon + \frac14 \omega_{\mu ab} \Gamma^{ab} \epsilon$, where $\Gamma^a$ are gamma matrices

ACuriousMind

@Sanya Well, the new ones will be crisp, but that won't save the soggy ones

Mostafa

@ACuriousMind Phone is invented for you to call others whenever you want, not the other way round. Don't forget that.

ACuriousMind

@Mostafa I'm not the kind of person that lets a phone just ring and doesn't answer it. I would have to be dying or something or that to happen.

Ben Niehoff

I'm not the type of person whose phone ever rings :P

mine is an internet device

Sanya

13:49

@ACuriousMind the mix might still taste better :o

ACuriousMind

@Sanya Hmmmmmm

You make a convincing argument

Hm, it's not as good as all-crispy cereal, but it's much better than the all-soggy abomination!

Ben Niehoff

the solution is to not pour liquid into your cereal

bleh

Anonymous

I eat cereal directly from the box

Anonymous

Much better :P

Mithrandir24601

@blue That's such a student-y thing to do... :/

Anonymous

13:53

@Mithrandir24601 Bringing a bowl...pouring milk...bringing a spoon...ugh...too much work :D

Mostafa

@BenNiehoff Are you using a 4G or LTE network?

@BenNiehoff on a 4G network everything (including calls) is IP-based. No traditional circuit-switched telephony.

It's all Internet.

Mithrandir24601

@blue I don't really like cereal either way :P

Anonymous

@Mithrandir24601 Even I don't like most cereals except this :P

Anonymous

These are really tasty ^ :P

Mostafa

13:57

@blue These are all true, still we see news like this almost every day:

Madrid cracks down on 'manspreading' on public transport

Mithrandir24601

@blue Erm... No thanks - I'll stick to my good ol' delicious porridge (occasionally with honey and cream :) )

Mostafa

Take care when you went back to Madrid ^ @AccidentalFourierTransform

Jaime Gallego

@Mostafa Wtf

ACuriousMind

@Mithrandir24601 Ewwwwwww

Mostafa

@JaimeGallego oh I forgot you're in Madrid too. Don't Manspread anymore please

Mithrandir24601

14:00

@ACuriousMind I thought so too, until I managed to get some proper pinhead oatmeal from Scotland. There's no comparison. I mean that in a literal way - it's a completely different thing to that horrid gruel-like stuff you buy in supermarkets

Ben Niehoff

ooh, neat, I happen to be in Spain at the moment

ACuriousMind

@Mithrandir24601 Hm. alright then, but I don't think I'm gonna import Scottish oatmeal to make porridge :D

@BenNiehoff Not in Belgium anymore, or just on a trip?

Ben Niehoff

I'm at a workshop in Benasque

it's in the mountains near France

Mithrandir24601

@ACuriousMind Yeah, I get that - I have difficulty getting Scottish oatmeal and I'm only in England :/

Ben Niehoff

my favorite type of oatmeal is what we call "rolled oats" in America...I think it might be similar to Scottish oatmeal, not sure

I know it was impossible to find in Cambridge :P

Mostafa

14:04

@JaimeGallego I think this solution kinda fits this big-list on MathOverflow:

99

Q: 17 camels trick

The following popular mathematical parable is well known: A father left 17 camels to his three sons and, according to the will, the eldest son should be given a half of all camels, the middle son the one-third part and the youngest son the one-ninth. This is hard to do, but a wise man helped ...

You add a box and the problem of the cat sitting on the nearby car is solved

Slereah

What's $\Bbb R^n \setminus \{0\}$ homeomorphic to?

Ben Niehoff

I was wrong! Rolled oats are pretty much the opposite of Scottish oatmeal. They're very coarse: chowhound.com/food-news/54417/…

Slereah

In 2D it's the cylinder but I'm not sure what it generalize to

I suspect $\Bbb R^{n-1} \times S$

Ben Niehoff

@Slereah S^{n-1}?

ACuriousMind

@BenNiehoff homeomorphic, not homotopic

@Slereah Other way around: $\mathbb{R}\times S^{n-1}$.

Ben Niehoff

14:10

ah, right

Slereah

Hm, I guess it makes sense?

Jaime Gallego

@Mostafa I don't think it is the same method, unless I'm missing something.

Slereah

It's basically spherical coordinates

Ben Niehoff

can't go losing dimensions with homeomorphisms, now can we?

ACuriousMind

@Slereah Indeed

@BenNiehoff No, sir, certainly not!

Slereah

14:11

Well I mean

The empty set is of dimension 1 and 2

And it is homeomorphic to itself

Ben Niehoff

Mathy people: what's the middle Hodge number of CP^n?

ACuriousMind

...I don't have any Hodge numbers memorized.

I think that may be something for @Danu

@Slereah wat

Many would not even allow the empty set to be a "space".

Slereah

Some do :p

The empty set is a manifold of every dimension

ACuriousMind

Yeah, that's precisely why you don't want to allow it. All it does is produce stupid counterexamples

Slereah

With the atlas $\{ \varnothing, \varnothing \}$

Ben Niehoff

14:16

the Wiki article claims the middle Hodge number is always 1, if you trust that...

Slereah

All of its non-existence open subsets are diffeomorphic to subsets of $\Bbb R^n$!

It's even smooth

It's the best manifold really

user228700

Anybody here (from India) have a subscription to Netflix?

heather

@Kaumudi.H hello =)

Anonymous

@Kaumudi.H Why? You can get a free one month subscription anyway

user228700

@blue ...why doesn't that seem to be working? >.<

user228700

14:24

@heather Hey! :-) How goes it?

Anonymous

@Kaumudi.H What isn't working?

user228700

@blue Netflix is asking me to pay upfront.

user228700

What is this 1st month free scheme you speak of? :-(

Sid

Huh, really?

user228700

Yeah.

Sid

14:26

There used to be one, I think

Anonymous

@Kaumudi.H For the first one month they won't charge you anything. You just need to enter your debit card details though and cancel it after 4 weeks.

2

Sid

Lol

user228700

@blue Huh.

heather

@Kaumudi.H well =) how goes it for you?

user228700

Same here :-) What have u been up to? You're on vacation, right?

Anonymous

14:27

Anonymous

You should be getting something like this ^

user228700

I do, yeah. Debit card, debit card, hmm...

user228700

I'll check it out further, thanks :-)

user228700

What? 18+? Everything is 18+? Wtf. (I am 18, but still)

heather

@Kaumudi.H I was for a bit, not any more

user228700

14:31

@heather Ah, OK...

Anonymous

I just turned 18 ;D

user228700

@blue Belated happy birthday! :-)

Sid

@blue Me too! Precisely 9 days ago.

heather

i've been reading a lot

user228700

@heather Textbooks?

heather

14:31

Ayn Rand in particular.

@Kaumudi.H yeah, those too - an abstract algebra book.

user228700

@heather Ayn Rand?!

user228700

What are u doing reading Ayn Rand?! What are u reading?

heather

sort of, she's a good writer

Sid

@heather Ayn Rand.. Great. Pretty good writer.. or so I have heard

heather

I've read Atlas Shrugged and the Fountainhead and some of the essays in the Capitalism book.

@Sid she is.

user228700

14:33

@heather Oh, all of 'em huh. What did u think?

Anonymous

@Sid Mine was one month back :P Belated Happy b'day to you too

ACuriousMind

Jun 7 at 22:11, by ACuriousMind

@Avantgarde philosopher who thought novels were a way of expositing her philosophy would be more accurate :P

heather

@Kaumudi.H not nearly all of them - there's another fiction book by her, "We the Living" that I might read. Also another book of essays. I thought they were pretty good - I'm still thinking about them.

ACuriousMind

:P

user228700

@ACuriousMind ^

user228700

14:34

@heather Huh. OK...

Sid

@ACuriousMind That is... a very accurate summary of her.

heather

i thought a lot of her ideas made sense, but i don't really know enough to make great judgments about some of them.

user228700

I am yet to read any of her books but I have heard overwhelmingly negative opinions about most of her books, which is why I'm still on the fence.

ACuriousMind

Also, one should note that most philosophers don't think very highly of objectivism.

(I don't either :P)

heather

huh. i didn't know that.

@Kaumudi.H they're very well written, I must say that.

Sid

14:37

She actually talks more about anti-communism in her books more than anything else. Exactly what ACuriousMind called expositing her philosophy

Also, Ayn Rand completely denounced all leftists, moderates during her time which makes her quite controversial

heather

is there a special meaning to "exposit" i'm not grasping here? it just means to explain something, or talk about something.

Sid

Nope. or Nothing that I intended apart from that

heather

just making sure.

bolbteppa

Think I see how to rewrite the covariant derivative as you wrote it

Sid

So,basically you either love her or hate her which pretty much decides whether you like her books or not

bolbteppa

14:42

(If you have a philosophy more suited to a fantasy book and then take social security after spending your life denouncing it, says a lot)

ACuriousMind

@heather No, it has no special meaning. I just happen to think that the lengthy parts that are really more about her worldview (thinly disguised as one of the characters holding it) are not good storytelling. If you want to teach people your philosophy, write a book on philosophy, not a novel. There's nothing intrinsically bad about a story being used to convey a particular viewpoint, but if one can feel that that is the primary purpose of the story, I can't really enjoy that.

Slereah

Are we talking about Ayn Rand

ACuriousMind

Apparently so

Abcd

Do electrons travel slowest in the 1st orbit because v is inversely proportional to n ?

ACuriousMind

@Abcd Electrons do not "travel slowest" anywhere because there is no classical motion in an atom. The electron has no "speed", just some quantum-mechanical average momentum/speed that doesn't really correspond to any motion

Anonymous

14:45

@Abcd In Bohr's model that's true I guess.

Abcd

@blue Yeah I was studying Bohr's model

Slereah

Please, we can totally define a speed

Just as the motion of the wavepacket

Abcd

@blue I think it should be fastest instead of slowest

I tried to edit my message but was late...

Anonymous

@Abcd yea

Slereah

though to be fair, electrons in orbit aren't in wavepacket going around

ACuriousMind

14:46

@Slereah I said it has a quantum mechanicall average speed. But it doesn't correspond to motion, not even like in a wavepacket, since the orbital is a stationary state

bolbteppa

$\rho^{\alpha} \nabla_{\alpha} = \rho^{\alpha} \partial_{\alpha}$? :(

Slereah

@bolbteppa what

Avantgarde

@Kaumudi.H I agree :D

bolbteppa

15:27

(Oh it's easy)

The Dark Side

15:47

^ (Covered traces of a failed experiment.)

Ignore.

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