The h Bar

David Z

12:15 AM

@skillpatrol my issue with that is, if it's a resource recommendation, what resource is it recommending? As I understand it, the asker already has the books and is just asking how to use them. That's not resource-recommendation in my view.

dmckee

12:30 AM

@skillpatrol It's an input tool---a device that records your drawing as input to the computer---not a tablet in the sense that you mean when you refer to an ipad. But they're not going to stop calling them that: Wacom was selling "tablets" for two decades before the ipad came on the scene.

They do make them now with their own OSs and high res screens, but that's a little out of by budget.

@ChrisWhite The only question I'd have is does the OP mean "proper" in the technical sense or does he just mean "correct"? In the latter case he has presumably heard a garbled version of "gravity is a non-inertial pseudo-force in GR" and is trying to sort out the clash with his previous Newtonian learning.

David Z

@gonenc kind of looks like it could be Inkscape (or an equivalent like Illustrator), though done by someone with a considerable amount of skill. But only Floris can tell you for sure.

DanielSank

1:11 AM

Huzzah! Didn't die in Yosemite.

dmckee

@DanielSank So you know rule #1: no selfies with the animals.

Saw a mom encouraging her son to "Get closer to him [a moose!], dear." once.

There isn't enough facepalm in stock for that. But the rangers showed up with dart guns and rifles and made them stop before anyone got dead.

Hmmm .. than might have been Yellowstone.

DanielSank

1:56 AM

@dmckee Oh... my..... people are stupid.

Sometimes I am sad that we think it's better to shoot the moose than let it hurt someone.

It's not the moose's fault that some people are fantastically stupid.

dmckee

@DanielSank My impression was they'd fire the darts first.

But if it charged, there wouldn't really be enough time. Sad.

DanielSank

Moose are really really big, as you know.

Darts? I dunno....

dmckee

@DanielSank Hypodermic darts. Presumably big doses, too.

DanielSank

I mean, certainly protecting the child seems like the right thing to do, but still...

I guess. What drug can drop a moose in short order though? Sheesh. I mean those things are BIG.

Musta been like a liter of sleepytime drugs.

(Should also nail the mom with one of those...)

dmckee

@DanielSank On the nature shows they slow down and get drowsey in a few tens of second. Which wouldn't do anything in the event of a charge. I assume that was what the rifles were for.

DanielSank

2:00 AM

That is really amazing.

David Z

@DanielSank that was my thought

DanielSank

I just really feel bad when people do stupid things and animals get hurt for it. Not their damn fault.

Sorry, I'm on tilt because of an NPR story I heard on the drive back. A lady was dogsledding the North American arctic and ran into a female polar bear with cubs.

She said she was ready to shoot it if it hurt her dogs. I just.... kill three polar bears because you went out joy riding and ran into someone else's back yard and appeared to threaten her children?

Gross.

I mean I get it, but still.

DanielSank

2:26 AM

Anyone here understand noise really well?

skill patrol

4:08 AM

Good point @DavidZ

thanks for the info @dmckee :-)

NeuroFuzzy

4:27 AM

@RajeshD :D your wish came true!

Rajesh D

4:50 AM

@NeuroFuzzy : Did not get it. What is it?

my comment getting starred!

John Rennie

6:09 AM

@ACuriousMind Non-nerds refer to the box containing the computer as the hard drive and the screen as the computer. When you first start doing end-user support this confuses the hell out you :-)

Actually I used to use my UPS for ripening fruit. I put the fruit in a closed box and left it for 48 hours on the UPS, where the constant 40ºC would ripen it beautifully.

Sadly I've switched to a more efficient UPS that doesn't generate enough waste heat to ripen fruit, though it has substantially reduced my electricity bill.

3

@gonenc I use Google Draw. It's a bit basic, but it's free and with a bit of practice can do pretty good illustrations.

NeuroFuzzy

8:55 AM

@RajeshD Yes. Your comment "hope this gets starred"!

ACuriousMind

9:25 AM

@JohnRennie Oh, I see! That's indeed confusing

@DanielSank Isn't the point of noise that it's unintellegible sound? ;)

Pandya

10:04 AM

When you rub your hands heat is generated by friction right? I think when you do something/anything heat generates/releases (Another/Every form of energy transfers at some extent to heat energy). I am looking for opposite of it!

ACuriousMind

@Pandya Heat means the flow of (mostly thermal) energy in physics. You mean thermal energy.

Also, it sounds like you are looking for a fridge ;)

Pandya

@ACuriousMind We have to continuously supply electrical energy in order to run fridge.

ACuriousMind

And you have to keep rubbing your hands to keep producing thermal energy, where's the difference?

Pandya

see once you start/trigger burning of fuel, then it continuously gives heat-energy from chemical energy. I am thinking if there any process that can absorb heat once you trigger it (not supplying work continuously)

Is there any special matter/process which has negative heat potential or say it requires/absorb heat in order to continue itself?

Ask me if this violates second law?

ACuriousMind

I'm not convinced the question is well-posed. Take a large block of a cooled-down material. It naturally "absorbs the heat" from its surroundings until it is at thermal equilibrium. This essentially does what you want, but it's not even a process.

skill patrol

10:26 AM

The so called zeroth law says it is impossible. Heat only travels from hot to cold.

Pandya

@ConstantineBlack Can you give some example of endothermic process that may be useful in day-to-day use?

Icosahedron

3:55 PM

@Pandya Endothermic chemical reactions?

That is only one of many endothermic processes, read about more examples here.

@skillpatrol This is not fully phrased.

Physics Meta

5:02 PM

0

Q: Finding which user was removed

I just lost 55 reputation because a user was removed. I know that there is not much that I can do about this, but is there anyway that I could see which user was removed?

discussion

T Abraham

6:27 PM

Should my question be a physics one instead of in the math SE?:

0

Q: Numerical integration with matrices

I have a matrix integration problem. It is based on the first integral under the section, "energy transfer efficiency and transport time" in the article, environment-assisted transport. There is a function, $\rho(t)$ that is the most important in calculating the integral but is a time-dependent m...

integration matrices improper-integrals

ACuriousMind

7:00 PM

@TAbraham No, it's fine where it is, I think.

skill patrol

@ACuriousMind Hi pal :-)

ACuriousMind

Hiya

skill patrol

what did you think of my attempted answer to Pandya's question?

ACuriousMind

@skillpatrol Well, the zeroth law is a statement about thermal equilibrium. It seems to me that we were not considering necessarily equilibrated systems here

skill patrol

true

@ACuriousMind btw, how do you like/dislike my new name?

ACuriousMind

7:15 PM

@skillpatrol I don't feel strongly either way :P

skill patrol

:P

Danu

7:45 PM

Hi all

skill patrol

hi pal

ACuriousMind

@Danu Is it me, or have your visits become rarer?

You're not gonna disappear like Phonon, are you? :P

Danu

@ACuriousMind No worries, I won't.

Like I said, I'd been very busy with that talk I was preparing

More generally, exams are approaching

skill patrol

sensitive ones usually disappear

ACuriousMind

@Danu What time span does "approaching" mean to you?

I know people who call two months "soon", I know those who say a week's plenty of time

Danu

8:01 PM

@ACuriousMind I'm getting scared about my "Riemannian Geometry" course

(read: Course on Chern-Weil theory)

We're getting to the point where my lack of topological knowledge is becoming inexcusable

skill patrol

I guess it depends on your time management perspective.

Danu

@skillpatrol What do you mean by that?

skill patrol

He asked what "time span"...

ACuriousMind

@Danu Your lack of topological knowledge has always been inexcusable :D

0celo7

@ACuriousMind What is the cover of QoGS supposed to be, anyway?

Danu

8:03 PM

@skillpatrol I was replying to your earlier comment.

6 mins ago, by skill patrol

sensitive ones usually disappear

skill patrol

oh, sorry I did use the arrow :(

ACuriousMind

@0celo7 Not the slightest idea

Danu

@ACuriousMind Yo' momma has always been inexcusable!

0celo7

I am officially a high school graduate now.

I have my diploma and everything.

HDE 226868

@Ocelo7 Nice!

Danu

8:05 PM

Congrats

I remember those days

TIME TO GET REKT AYE MATE

0celo7

Thanks!

Danu

or something along those lines :)

0celo7

I graduated yesterday, I'm currently not feeling well.

skill patrol

@Danu sensitive users can be sensitive to the point of constantly deleting their accounts and disappearing, no?

0celo7

Too much reking.

My sister's graduation gift to me was my first flask.

Danu

8:07 PM

@skillpatrol That comment seems very unrelated to what I was talking about. Were you talking about something different?

@0celo7 Why'd you need a flask? You can walk around with booze out on the streets now :P

[woops, USA lel]

ACuriousMind

@Danu lol

skill patrol

19 mins ago, by ACuriousMind

You're not gonna disappear like Phonon, are you? :P

Danu

@skillpatrol Right, but you probably know I'm not sensitive :P Nor was/is Phonon

Also, the disappearing in this context was more like "stop showing up" than "delete account"

skill patrol

ok

Danu

@0celo7 Had some good parties?

I went to my ex-gf's little sister's high school graduation (in the US) last summer. Was kinda fun!

Mostly fun-ny though

HDE 226868

8:11 PM

@Danu How so?

Danu

@HDE226868 So overly official and pretentious :D

HDE 226868

@Danu Ah, that makes sense.

skill patrol

was it "dry"

ie nonalcoholic

HDE 226868

All of my final exams are over, save one final project. The thing is, two out of four days of testing remain for everyone who had fewer APs and an unluckier exam schedule. I'm in for two of the most boring days of the school year. Although turns out that my calculus teacher plays backgammon, so that could lead somewhere interesting.

Danu

@HDE226868 Drinking is fun alone, too.... sometimes :P

ACuriousMind

8:15 PM

@Danu: Have you given your talk yet?

HDE 226868

@Danu I feel like there's ice pops or something on the last day, if I remember last year correctly. You cannot get much further away from drinking that that. Which is all good with me; alcohol is decidedly uninteresting.

Danu

@ACuriousMind Yush

@HDE226868 Ah... okay

HDE 226868

@Danu What can I say, I'm 16. What was the talk for?

Danu

@HDE226868 In Europe.... Hahaha, it's alright :) Drugs are bad for you anyways.

The talk was on BPS black holes in higher dimensions, but without the SUGRA and BPS :D

My half of the talk was rather pedestrian

HDE 226868

Sounds moderately interesting.

innisfree

8:30 PM

@danu my impression is that the fraction of physicists that don't drink alcohol is higher than in the general population and higher than in non-academic graduate level jobs

Danu

@innisfree Definitely quite high

Perhaps the per capita alcohol consumed averages out, though? ;D

innisfree

hmm i'm not sure, i don't think it would be possible to function as a professional physicist if you were abusing alcohol

Danu

@innisfree I think there's room above the average without abusing alcohol ;)

innisfree

yes, that's true. i sometimes wish that we could develop brave-new-world-style drugs that didn't have such damaging affects on people's lives as alcohol

Danu

8:46 PM

@innisfree I think it's quite easy to find things that are not as bad as alcohol

innisfree

Tea?

ACuriousMind

I like Banks' Culture more: You can choose to have at-will-activated glands that will emit all kinds of things if you so desire. Granted, the Culture doesn't need people to do anything anymore.

Danu

To me, cannabis (when not used $>2$ times a week) has never really had any serious repercussions in terms of hangovers etc. Of course, I'm aware of the long-term problems associated with smoking stuff ;)

@ACuriousMind Hmm... :P

skill patrol

@ACuriousMind sounds so ... hormonal

innisfree

i'm not sure either of those things are desirable, though. we have to experience disappointments, unhappiness etc in life, else we'd never resolve to improve ourselves or achieve anything. if i could take a soma every-time i felt any hint of unhappiness, what would become of me!

Danu

8:50 PM

@innisfree ...but that's not what cannabis does :P

If anything, it intensifies my feelings in all respects. Getting high in the months after a break-up really isn't fun (to me)!

ACuriousMind

@skillpatrol Of course you can also have control over your hormonal glands, but that would make life kinda boring :P

I think some negotiators from the Culture actually use that to be more controlled, Banks' world is a very weird one that hovers somewhere between utopia and dystopia

innisfree

sounds interesting, i'll put it on my list

skill patrol

sorta Logan's Run like

I don't recall Farrah Fawcett being in it?

ACuriousMind

@skillpatrol The Culture is far more utopian. The Culture is a galactic civilization that spans thousands of habitats, its citizens are effectively immortal and can choose to be remodeled into whatever living form they like (or even become purely stored in digital form). There's (officially) no government, (actually) no scarcity.

alarge

@innisfree Plenty of alcoholics in physics/mathematics, quite famous ones too. Mental illness is not that rare either if you go to Wikipedia and start reading up on some of the famous names.

ACuriousMind

8:56 PM

Also, it's a book series, not a movie

innisfree

@alarge who?

Danu

Of course, we must mention Erdos, who is famous for considering a month's long break from amphetamines a total waste of his time

(and who was a famous mathematician!)

From Wikipedia:

After 1971 he also took amphetamines, despite the concern of his friends, one of whom (Ron Graham) bet him $500 that he could not stop taking the drug for a month.[18] Erdős won the bet, but complained that during his abstinence, mathematics had been set back by a month: "Before, when I looked at a piece of blank paper my mind was filled with ideas. Now all I see is a blank piece of paper." After he won the bet, he promptly resumed his amphetamine use.

skill patrol

sounds like what steroids is to sports

skill patrol

9:13 PM

over 9000 hours later...

0celo7

11:24 PM

@ACuriousMind What are the prereqs for QoGS?

10 Internet Points to whoever can tell me what this image is supposed to be.

Reverse Google images is amazing.

skill patrol

firing a cannon from the top of a mountain

0celo7

@ACuriousMind It's a diagram from one of Newton's works.

Interesting picture for a book on quantum mechanics.

skill patrol

do i get the points :P

0celo7

^^+10

skill patrol

:D

ACuriousMind

11:33 PM

@0celo7 Uhhh...basic familarity with Hamiltonian mechanics as symplectic geometry I'd say, and you should have seen the usual QM and QFT quantization procedures. It doesn't hurt if you know homological algebra to follow the BRST constructions, and I guess you should have seen Grassmann variables and (super-)stuff to follow the very brief introductions to these things.

And now you've reminded me that I still have to do most of the exercises in there :P

skill patrol

Newton's cannonball

Newton's cannonball was a thought experiment Isaac Newton used to hypothesize that the force of gravity was universal, and it was the key force for planetary motion. It appeared in his book A Treatise of the System of the World. == §Thought experiment == In this experiment from his book (p. 5-8), Newton visualizes a cannon on top of a very high mountain. If there were no forces of gravitation or air resistance, the cannonball should follow a straight line away from Earth, in the direction that it was fired. If a gravitational force acts on the cannonball, it will follow a different path depending...

0celo7

@ACuriousMind Homological algebra? I might know some of that, what's it entail if I have to catch up? (I got a Barnes and Noble (book store) gift card.)

ACuriousMind

11:51 PM

@0celo7 (Co-)homology of exact (co-)complexes, in particular computing it by certain resolutions, but I don't think you need to read a book on that, especially since the mathematicians will probably focus on proving things that are absolutely worthless for this particular and small application

skill patrol

they prove a lot of things just for the sake of proving them

0celo7

@ACuriousMind How much of the book did you follow?

ACuriousMind

@skillpatrol I know what math is :P

3

skill patrol

before we can do them, we learn by doing them

@0celo7 the Wikipedia article has some good links.

ACuriousMind

@0celo7 Good question. Enough to be able to look everything in it up, I'd say ;) I couldn't do the BRST construction on my own for the life of me, but the parts that were not about that homological perturbation theory setup I followed thoroughly (also because I was more interested in the quantization process than the BRST construction itself)

skill patrol

11:58 PM

@ACuriousMind I know, you know pal :-)

0celo7

@Icosahedron What ones?

@ACuriousMind Yeah, I'm not too interested in any detailed calculations, I just want to get a good overview of gauge theories, constrained systems, etc. because it's very applicable to BBS and BLT.

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