The h Bar

:D

It's all good in da hood.

By the way, @DanielSank, did that number include area code? I never know

@BernardMeurer Yes.

12:41 AM

Alrighty, awesome. Maybe I get into UCSB and then me, you, and @FenderLesPaul can be bffs and go for strolls on the plentiful daisy fields as we sing and jump

@BernardMeurer Perhaps.

I gotta quit reading books to my cousin. They're making my imagination weird

How old is your cousin?

@BernardMeurer The problem with going for strolls in and around UCSB, is that many of the best walking routes take you past the lagoon or the slough. Either way you might be in for a rather strong odor (depending on the recent weather).

I like to walk so I just got used to it. Used to know all the path around the lagoon and out near campus point. Also where you could scale the cliffs if you (a) had misjudged the tides of (b) the campus police might misconstrue your presence on the beach near a party as "minor in possession".

Not that the latter applies to you, but it applied to me for a while.

12:59 AM

@guest five or so

Hahahaha thanks for the tips @dmckee; what about daisy fields tho?

Isn't reading to him or her considered home schooling?

@BernardMeurer The Chancellor's Lawn sometimes has dandelions. Does that count?

2:08 AM

@DanielSank quantum gravity

I'll be working with a person in KITP (ideally Don Marolf)

@FenderLesPaul I believe you wanted to ping DS there. (Use the little arrow! :P)

Oh oops

my bad

2:42 AM

@FenderLesPaul So you're definitely coming here?

@DanielSank The only school I'd consider over UCSB is Princeton if I get in

which basically means yeah I am coming there

@FenderLesPaul I guess Princeton is a good option because of your subfield?

yeah

@FenderLesPaul Screw that. Surfing.

Haha totally

2:54 AM

Friend of mine used to bring a big wheely black board to the beach and do his QFT homework.

Try that in Princeton.

To be straight for a moment - KITP is pretty neat. There are a lot of conferences and people going through there all the time.

If you don't mind I'd like to give you two bits of advice:

1. wherever you go, make sure there is more than one person you'd be interested to work with.

2. Make sure you go somewhere that the students are happy.

By the way, assuming your user name reflects your interests, if you do come here you have to teach me to play rock guitar, and I'll teach you classical.

@DanielSank Thanks for the advice! I really appreciate it :)

as for people to work with, yeah that's one reason UCSB was my top choice

Yes, item #1 is important.

since there are around 4 or 5 people I'd love to work for

That's good.

mainly Don, Gary Horowitz, Joe Polchinski, and David Bernstein

2:59 AM

Good for you. Those are all excellent researchers and nice people.

I'm told the students are happy there; a friend of mine who graduated from Cornell 2 years ago is there now working for Joe and loves it

And yeah I would love to teach you rock guitar haha that sounds dope

Yeah, UCSB is pretty good on the grad student happiness scale.

:3

This sounds dumb, but sunshine really does help.

Yeah I'd imagine

3:00 AM

Princeton is obviously an awesome department too.

Don't get me wrong.

Hehe

5:49 AM

WAIT

@DanielSank Are you into classical?

@BernardMeurer Yes.

That's my favorite piece of music. ^

I haven't played in years though, so I'm pretty terrible at the moment. It's on my todo list to play more and regain my former glory.

user54412

6:19 AM

@FenderLesPaul Well then, looks like you, me, and @DanielSank will have to meet up in person, since we're all gonna be there ;)

7:59 AM

So, would anyone else prefer if we taught radians in school instead of degrees?

user116211

8:27 AM

@SirCumference: We were taught radians prior to trigonometry ; our book had a dedicated chapter on circular measure problems.

Sadly, most kids aren't

My elementary school math teacher didn't know what a radian was...

It blows my mind

user116211

It was included in our std.x syllabus; it still is.

user116211

@SirCumference: WTF!!

You're the minority

user116211

@SirCumference: Nay!!

8:29 AM

Yay, I'm afraid

I've never met one person who was taught radians before degrees

user116211

@SirCumference: Add to the bonus, we were taught centesimal system also ;)

In fact, why on Earth are we taught degrees? They're useless and arbitrary

user116211

@SirCumference: Won't say such but yes much less useful than the radian ...

You don't think they're arbitrary?

Let me ask you this: why are there 360 degrees in a circle?

There could have been 480, or 173, or 91004

They're baseless

At least radians have an exact, indisputable definition

user116211

@SirCumference: why on Earth, are we taught Newtonian Mechanics? They're useless in the long run! We could have learned Hamiltonian Formalism, then Special Relativity ;P

8:34 AM

Oh boy, you missed a long conversation

I argued against teaching Newtonian mechanics

Newtonian vs Relativistic physics

Jan 29 at 0:01, 1 hour 1 minute total – 213 messages, 8 users, 4 stars

Bookmarked Jan 29 at 1:03 by Sir Cumference

user116211

@SirCumference: Jaws dropped!!!

So yeah, an hour long conversation...

But I can understand Newtonian mechanics. GR and QFT are too complicated to teach most high school students

And Newtonian mechanics gives good approximations at non-relativistic speeds

user116211

Yet things like degrees and script handwriting are useless

Why are we teaching this?

user116211

@SirCumference: even if we are taught, there must be at some point, we need to be taught circular measure and it's good to get this topic included in the syllabi of our country.

8:38 AM

Degrees?

But why not radians?

They're infinitely better

exaggeration

But you know what I mean

user116211

@SirCumference:We are consuming degrees from std.iv days. But at last in std.ix, we got to learn the circular measure; some intricate problems and yeh we excel at it and from that day, we hardly face degree in our curriculum. come to Ind;P

I know, but we shouldn't even be teaching degrees

They should just die out

user116211

@SirCumference: They are indeed arbitrary but can't be useless! If it gets abolished, then so do Imperial system of measures.

Imperial is different but isn't necessarily worse

Crap

user116211

@SirCumference: Yes. Not worse.

8:43 AM

But degrees are just nonsensical

user116211

Worst!!!

They have no base

user116211

Agreed.

user116211

9:37 AM

@BernardMeurer: Heard Coldplay's Hymn for the Weekend?

user116211

10:43 AM

@SirCumference: Scientific fact: If you took all the veins from your body and laid them end to end, you would die.

user116211

Splendid!! The most interesting fact, I've ever known.

12:44 PM

@SirCumference Imperial is necessarily worse

1:10 PM

@DavidZ are you around?

Listening to your song now @user36790

user116211

@BernardMeurer: Imperial sucks!!

@BernardMeurer I suppose so

@DavidZ If someone is a partner in a company, could one say they are self employed?

I have no idea

user116211

@BernardMeurer: where is our 10yr old 0celo??

1:23 PM

@user36790 Banned for the weekend

@DavidZ darn it

user116211

@BernardMeurer: WTF!! Why?? When???

user116211

Okay! no reason

@user36790
Why: None of our business, he was doing something wrong
When: A day ago, or so

user116211

@David Z: Can I ask you a question?

@user36790 Never ask that, just ask the question :p

user116211

1:26 PM

...........

@user36790 No. No questions allowed. In fact for asking that one you go directly to jail, do not pass go, do not collect $200 :-P

Seriously though, (1) yes (2) I do agree with Bernard's advice

user116211

:O

user116211

Okay, let you take an isolated gas system in a container of volume $V$; $N$ and $E$ are number of particles and energy of the system-both are fixed. During the equilibrium, what would be its entropy?

user116211

Of course, equilibrium would be dominated by the macrostate which has the max. multiplicity.....

user116211

1:31 PM

So, should I write the entropy of the system at equilibrium as $S=\ln \Omega(E,V,N)\;?$

user116211

But the fundamental Postulate (ergodic hypothesis) says that all microstates having the same $E$ are equally likely at equilibrium....

$S = \ln\Omega$, don't forget the log

sneaky :-P

Indeed, it is engraved on his tomb stone :P

user116211

So, when the system has all its particles at the left half of the container, that is the macrostate would be $(E,V/2,N)$, then won't the entropy at equilibrium be $S= \ln\Omega (E,V/2,N)\;?$

It's not at equilibrium in that state, though.

Or to put it more precisely: in order for a system to be at thermal equilibrium in the macrostate $(E, V/2, N)$, then external conditions should be such that it will stay in that macrostate.

(I think... this is not exactly my specialty)

user116211

1:41 PM

@David Z: Then why is it that the postulate says all microstates having the same energy are equally likely at equilibrium?

Not sure I see where you're going with this

user116211

:(

I mean, how does the particles all being in the left half of the container imply that some microstates are more likely than others? (which is what it seems like you're saying)

user116211

Okay what does actually the fundamental postulate say?

user116211

The microstates, no matter what the volume may be, all have same energy, IMO, are all equiprobable over long time scales.

1:49 PM

Right...

user116211

:)

user116211

The problem is with the word equilibrium in the postulate....

Are you thinking about an infinite time scale?

user116211

No, finite but greater than the interaction time between the particles.

user116211

The system is isolated and all the microstates whether they belong to the macrostate $v/2$ or $V$ all have the same energy and all would occur equally likely....

user116211

1:55 PM

But since, the macrostate with $V$ has the greatest multiplicity; it would dominate....

@BernardMeurer Murica.

user116211

Now, won't I call that macrostate $V$ the only equilibrium condition? I thought so, but the postulate tells there can be other microstates which occur at the equilibrium that correspond to macrostate $V/2$; now won't I call the later fluctuation?

@user36790 Yes, which reflects the fact that the fraction of the time in which all particles are in the left half of the box is exceedingly small

user116211

:)

Or, wait.

user116211

1:58 PM

:/

I just noticed you're talking about macrostates with different volumes. I think that's wrong. The macrostate is always $(E, V, N)$.

Or at least, we represent the system by a macrostate parametrized by $(E, V, N)$.

As long as we do so, the resulting model exhibits thermal equilibrium.

user116211

Then you consider the particles confined to the left-corner of the volume of the container $V$?Won't that be $V/2$?

If the particles are all in the left half of the box at some particular moment, you can represent the system at that moment by a macrostate parametrized by $(E, V/2, N)$, but the resulting model does not exhibit thermal equilibrium - and in fact is not very useful because it very quickly ceases to be valid.

user116211

Yes, that corresponds to the macrostate $V/2.$

@user36790 Yes, I'm saying that, in the model of a gas in a box of volume $V$, even if all the particles are in the left side of the box at some moment, you should still consider the gas to be in the macrostate $(E, V, N)$

user116211

2:02 PM

Enlightenment!!

In a sense, a macrostate represents a whole collection of possible microstates. You can't look at a single microstate (i.e. a single list of positions and velocities) and say "this corresponds to the macrostate X" because a given microstate can be part of many macrostates, depending on how the system is defined.

user116211

@DavidZ: You are Buddha!!

user116211

Spelling sucks!!!

Ah, well, good if it makes sense

Though again, this is not really my area so I'm not 100% sure of all that

2:19 PM

@ChrisWhite yay!

Yes we must meet up!

2:29 PM

@BernardMeurer Also, the imperial system has a base. Yes, that base is the metric system, but it's an imaginable distance. Most children can imagine a foot as actually being an average foot length.

Degrees are not at all helpful. They are so arbitrary that they have no redeeming qualities.

If I ask you to draw one degree on the spot, you probably couldn't.

Damn Babylonians

@ACuriousMind Wait, was it the Babylonians or the Sumerians?

@SirCumference Doesn't matter, both had the sexagesimal system

The Sumerians came earlier, but for some reason the Babylonians are blamed more often for it

Oh really?

Love how ya use "blamed" instead of "credited"

Nowadays, everyone's using the decimal system (except for those people who think we'll actually start using base-12)

So there's no use for degrees

user116211

Stress must also be given on Centesimal system. It has many benefits ...... well none!

user116211

2:45 PM

@DavidZ: So, a microstate can correspond to more than one macrostate?

Then there's also the pi vs tau argument

@user36790 Yeah, I think so. That doesn't mean you should start thinking of a system as being in multiple macrostates at the same time.

If we use tau, we can't have things like pi day or $e^{pi*i}=-1$

It's not like quantum states.

user116211

@DavidZ: Gotcha. Let me read a bit...

user116211

2:59 PM

@DavidZ: To each microstate there corresponds exactly one macrostate. :__O__ Check this pdf: ls.poly.edu/~jbain/physinfocomp/lectures/…

@user36790 This is true if your notion of macrostate is "equilibrium configuration given by energy, temperature, particle number" and you already assume that equilibrium configurations have uniform probabilities for their microstates, since you can compute energy, temperature and particle number for any given microstate.

user116211

3:16 PM

@ACuriousMind: So, who is correct? David Z or that pdf?

@user36790 Both, within their assumptions.

For DavidZ, a macrostate may be a collection of microstates that's not necessarily in equilibrium or uniform, and then you can't associate microstate<->macrostate uniquely.

user116211

@ACuriousMind: Got it.

user116211

@ACuriousMind: Thermal equilibrium doesn't exist at the level of microstates.

Reference https://www.physicsforums.com/threads/meaning-of-equiprobability-principle-in-statistical-mechanics.254543/ Do you believe it?

@user36790 Of course. Equilibrium is a statement about the probability distribution over the microstates not changing in time - that doesn't make sense for a single microstate since of course a single microstate changes in time.

3:45 PM

@user36790 for a given definition of the system (and its surroundings). That's what the PDF omits. (Rightly so, because it's usually understood)

Q: If you play more than one music track at once on a computer, does the sound heard get louder?

6:25 PM

0

Say you are using a computer and have multiple Youtube videos playing music (or any other video) at the same time, does the sound produced by the computer's speakers (or a pair of headphones) become louder than just playing one video? I.e. does the amplitude of the sound waves from multiple video...

Is this about physics at all?

user54412

Was wondering

@Danu Yes; the physics of out-of-topicness

user54412

I want to give the question the benefit of the doubt, though. The whole computer stuff could just be their way of saying they are comparing one sound source to two sound sources.

The question is essentially: Does my computer produce two separate sound waves when I play two videos?

I was ordered a Feynman tips on physics.

6:32 PM

@ChrisWhite Like I said in the comment I just wrote, the engineers designed the system to mimic two physical sources when you overlay things, so you could argue it on that basis. But I don't really like it for physics.

I did so as you advise - I learn from Landau and Feynman lectures but I use school books to learn to class test.

user54412

Well I'm not going to go out of my way to defend the question. It's either off topic or unclear.

That's funny. Though I continue to use English traditional units occasionally in class to emphasize the difference between dimensions and units. On the other hand I don't test the students on that wrinkle.

What are your opinions about Feynman tips on physics? Is this really helps to understand Feynman lectures and helps in solving Feynman exercises?

user54412

7:11 PM

Wait, you're seriously telling someone with no money to take on credit card debt for what is ultimately the university's purchase?! This is the most laughably stupid advice that could be given. — Chris White 17 secs ago

user54412

Was that too mean?

I think "stupid" might be a little much, but I approve of the sentiment. I also have to say that StrongBad often rubs me the wrong way. I try not to engage with him.

@ACuriousMind Despite you not reminding me, I finally got around to answering Arnold Neumaier's question.

0

A: Bohr on wholeness?

After an extended search through my copy of Pais' biography Niels Bohr's Times, I believe I have found what exactly what you are referring to. There were multiple times in his life when Bohr wrote about the definition of the word phenomenon. On pages 431-433 of my copy of Pais' book, Bohr's thoug...

@dmckee Btw, do you agree that that question should really be moved to HSM (as long as OP wouldn't object)?

user54412

@dmckee He's rubbed me wrong before too. I'll just delete that and move on to happier thoughts.

That said, I think of the interest paid on university purchases in the way I imagine that business types think of other "costs of doing business". There is a point of fairness but it is not worth losing a chance over.

7:18 PM

@ChrisWhite kinda funny

What branch of academia does StrongBad work in?

@Danu Seems reasonable to me. It's really about finding a primary (or at least secondary) source. That's historian work, right?

Where can I ask about mind hacks?

^ Lifehacks?

@Danu Oh. Sorry. :/

@dmckee Yeah, that's what I thought.

@ACuriousMind It's alright.

Finding it was a hassle!

7:21 PM

I can't ask about it on lifehacks because this question is marked off-topic.

Question was "How to control emotions?".

You'll want Jedi.SE for that.

2

You could check the rules on Cognitive Sciences. But there may not be a Stack Exchange for that.

And I certainly can't help you.

Worldbuilding? :P

user54412

Buddhism?

Sure. Ten years of steady meditation should help a bit...

user116211

7:23 PM

There is a proposal on MindHacks at Area 51;you may supoort this so that it may become SE: area51.stackexchange.com/proposals/91791/mindhacks

user54412

@Danu I figured it was about controlling one's own emotions, not instituting a police state that controls the thoughts of the populace :p

I would like ask about mind hacks, emotions, feelings and social.

user116211

Or you can ask Trump how he deals calmly with his vast following fans....

But I don't know where can I ask.

Do you know any service about mind hacks?

I am, by the way, disappointed in you guys' lack of appreciation of my above-posted answer! Took me more research than most physics answers! I guess you barbarians are not interested in history ;)

7:26 PM

@Danu Correct

user116211

Google it; there is no such thing till now at SE.

@hubot I don't even know what a "mind hack" is supposed to be

A trick to try to help with some cognitive task. Mnemonics. Mind palaces. Etc, etc, etc.

user116211

@Danu: ACM ceates history:P

HDE 226868

@Danu Correct

7:28 PM

@user36790 Have you and @BernardMeurer instated a fanclub? :P

@HDE226868 Et tu, HDE?!

::collapses of daggers to the heart:: (in case nobody got the reference)

HDE 226868

@Danu Hey everyone, I killed Caesar!

user54412

historical reference?

@ChrisWhite Unless they did a [Star Trek|Simpsons|Furturama|South Park|...] episode on it.

user116211

Vandal Savage killed Caeser ;/

They probably did.

7:31 PM

@HDE226868 Making it even more clear for the really dense? ;)

@dmckee Definitely

HDE 226868

@Danu Nah, I just wanted to say "I killed Caesar."

@dmckee simpsonswiki.com/wiki/Julius_Caesar#References

Figures.

BTW, If you get a chance to read the man's dispatches from Gaul, do it.

@dmckee I have read (parts of) the original, in Latin.

How 'bout that? ;D

::bows head in monoli^WAmerican shame::

7:40 PM

@dmckee D'aww

What did I do now @Danu?

user116211

@BernardMeurer: Liked the hymn?

8:04 PM

People and social are harder than Landau exercises.

8:19 PM

How to be clarify?

8:32 PM

@user36790 It's too pop-like to me, it just doesn't appeal somehow. I think I'm not into vocals mostly as well, prefer just instruments

9:30 PM

I'm grading the first midterm for my algebra/trig second semester class today. Some observtions.

* Many of these students have poor communications skills.

* Some of the ones who had other professors for the first semester didn't get Newton's 3rd law hammered into their heads hard enough.

* They are at once deeply attached to questions written with numbers instead of symbols and not actually very good at doing anything with numbers but putting them into their calculators.

Those are all a bit frustrating, but the last one makes me despair.

I let them use calculators, because there 10-25% percent who are completely helpless without them (*), but using them prevents them from actually remedying their innumeracy.

(*) My first adjunct semester I banned calculators on tests and went to great trouble to rig the questions to only have easy computations: simple ratios, one or two digits sums and differences and so on. I learned that more than a fifth of the class couldn't extract the square root of 25 by hand. And this at a first tier public research university.

9:45 PM

@ACuriousMind @DanielSank @DavidZ @dmckee @ChrisWhite @0celo7 and other 3k+ chat regulars. Some time ago I mentioned the possibility of having a regular (say, weekly) "Answer the Unanswered" aka "Cleanup" session where we all go around on the site and link questions (to the chat) that should be answered, closed, etc. that were asked during the last week.

I remember that the proposal was quite well-received. Are (some of) you up for actually doing something like this?

[The idea was stolen from TeX - LaTeX, where the session is curently ongoing]

I might pitch in if I was free and noticed it going on. I'm not going to be a regular at it. "Real" life is to hectic these days.

What was the average grade on the midterm?

@Danu I'm mostly unable to cast close votes because I run out of them every day as it is, and I already answer what I want to answer. I'm not sure what benefit this would have

@guest The current one or the historical one where they couldn't do grade school math?

Current please :)

9:51 PM

I'm still marking them. It'll probably be around 80% because I've learned how to write an exam that doesn't crush everyone in the room.

Students do complain that the test components are tough on their grades, but that's backwards: the other components are designed to give them a buffer against the tests.

So you give two "mid"terms?

I give six midterms and drop the worst. High frequency feedback and low stakes are both good for both student moral and learning.

How much weight do you assign to the final exam, if you don't mind me asking?

The physics majors have to be content with three exams, however. Because I expect them to be able and resilient. And because I need the class days badly.

@guest 25% in the intro classes (even weighting for homework, labs, midterms as a group and final). And the final is cumulative, but it is open-book.

Open notes too?

user54412

10:03 PM

@Danu not against it

Not in the intro class. For the upper-division all my tests are take-home anyway so they are open-resources.

I do let the intro students re-do any single page on each midterm. Not because I care about their grade that much but to encourage them to go back and learn whatever it was they didn't get at first.