The h Bar - 2015-03-31 (page 2 of 2)

« first day (1608 days earlier) ← previous day next day → last day (3322 days later) »

Glen The Udderboat

5:00 PM

Is it possible to embed a video (not a GIF) in a question?

It all started as a joke, when I got upset about no longer being the one true Jim and someone mentioned that everyone should change there name to a Jim name when I left the room. Spiraled from there to me being Jimdalf the Grey last month because of another comment I made.... yadda yadda..... I am the Lord your Jim!

Glen The Udderboat

Whip cream effect

@Jimnosperm LOL!

@GlenTheUdderboat You mean using a plugin like shockwave flash?

37

Q: Provide a way to embed videos in answers

To explain a point on this question, I made a video at screenr.com and linked to it. I tried to use object/embed markup, but it was just ignored, which is a good thing because it would not be a safe solution. But it would be nice if Stack Exchange found a safe and easy way for users to create q...

feature-request status-completed videos

The answer is: No, not on physics.SE.

Glen The Udderboat

@ACuriousMind Ah!

5:03 PM

You could add a lot of pictures in sequence and ask that the reader scroll through really fast

@GlenTheUdderboat We don't want to rely on embedded YouTube videos because we have no control over whether or not they are taken down. We want all needed information to be found in the post itself here, which means not relying on a video or image hosted somewhere else.

@Jimnosperm Haha! You're something else...

As mentioned, I am a tree

@Jimnosperm I'm a legit tree.

Full stack of StackEgg hearts :)

I'm a cat.

5:08 PM

@Jimnosperm you're a yellow box until you change your dp :D

Argh

0

Q: How does warped space cause gravitational acceleration?

As a layman, most of my understanding of Einstein's gravity comes from simple analogies, such as the "BOWLING BALL ON TRAMPOLINE" example, or alternatively the "ANT ON BOWLING BALL" example. While these analogies are great at explaining how the paths of moving objects can be altered by warped spa...

general-relativity gravity

Please VTC this abomination

@J.Musser I can't do that! Not without letting the community vote on the new one first. I would have changed it had they chosen Jim the Enchanter as my name

@0celo7 I'm currently in the process of choosing the correct reason. Unclear what you're asking? (I really don't know what OP wants)

I don't think he understands what potential energy is.

@ACuriousMind It's a dupe, I've seen this question at least 3 times before

5:11 PM

Yeah " If I let go a bowling ball at the top of the atmosphere, so that it has 0 starting energy"

He doesn't know what potential energy is.

@Jimnosperm physics.stackexchange.com/q/102910/50583, perhaps?

i dont know why he brought curved space into this O.o

@ACuriousMind probably

that may be the root dupe

It's nice that he hopes it's trivial so that we can get back to our lives

It's nice that he assumes we have lives we want to get back to

5:13 PM

@Jimnosperm you can do whatever you want.

@ACuriousMind Lol, we answer a physics question and get back to webcomics and more physics.

@J.Musser True, but I try to hide my omnipotence from the people around here. I don't want to frighten them

Oh god, Ellis has gone old physicist mode... mth.uct.ac.za/~ellis/Top-down%20Ellis.pdf

@Jimnosperm lel

Did Einstein ever have a crackpot phase?

5:15 PM

@0celo7 That's the Ellis of Ellis&Hawking?!

:(

YEAH

@0celo7 Many

I think he had a professorship in Math at Cambridge

@Jimnosperm Were they all "matter = geometry"?

I'm aware of those

Alfred Centauri

@Jimnosperm "the formula" is remarkably difficult to put into a few short words but, once recognized for what it is, it is easy to detect. Essentially, it involves getting the victim to accept an unearned guilt, the 'guilt' of having offended (humiliated, etc.) another. Your discovery that no one can offend you unless you choose to let them do so is your inoculation against "the formula".

I call it, All-There-Is, Ising. The Ising gives it life/reality, conscious witness. Space-time — 11dim 31 mins ago

Ising is love. Ising is life.

5:17 PM

@AlfredCentauri Makes sense to me

haha

@0celo7 Also the whole non-locality must be wrong thing. There's a good few. Not all are about physics though

Glen The Udderboat

@Jimnosperm Aren't Ising models used a lot in economics??

Who the hell upvoted that trampoline question...

Glen The Udderboat

@0celo7 Not yet. Where is it?

5:22 PM

It's a duplicate

@0celo7 I've given up on understanding single upvotes in any case. My threshhold for "what the hell happened here?" is somewhere around five votes now, I think

3

@GlenTheUdderboat I wasn't involved in the Ising model discussion

There a troll upvoter on this site, or perhaps multiple

At least 3 because they upvote each other

Can I join them? I want to VTC dumb stuff!

5:24 PM

get 500 more rep

489

BTW, do we VTC the inevitable April's Fools questions that will show up, or are they fair game for a day and closed on the 2nd?

This homework policy sucks, some of these closed questions are exercises or derivations I know how to do.

Glen The Udderboat

@0celo7 Perhaps unanswered questions should get upvoted automatically after some time. (Bad idea, but still, just throwing it in here.)

@ACuriousMind I'm partial to the VTC of joke questions

5:26 PM

@GlenTheUdderboat There is a bot that bumps such questions.

Glen The Udderboat

@0celo7 Yes, but bumping is not quite like upvoting.

@0celo7 Just answer some questions which don't require you to do derivations at all. If I only answered technical questions, I'd have far less reputation.

@KyleKanos Why don't we VTC the joke questions "as a joke"?

Sounds good to me

Glen The Udderboat

@Jimnosperm Why not migrate to joke.stackexchange.com?

6:12 PM

@ACuriousMind Is this guy asking why the fundamental theorem of calculus works?

Or is there something subtle...?

No, it's just the fundamental theorem

Them saying "Leibniz integral rule" would indicate that they know that one, though

So I'm not clear on what the problem might be

@ACuriousMind Where does that minus sign go?

The one in the first equality of the second line.

Typo, probably

6:33 PM

@Jimnosperm i should prob. change my name

@Jiminion Your call

7:21 PM

I should too

to acuriousjim

since that's not taken i guess

What could possibly go wrong?

I swear if that displaces Björn from the no. 1 spot on the @A list...

You'll get a lot of random messages about random crap.

.... Isn't that a B name?

@Jimnosperm I thought @ACuriousMind started with an A...

I meant Bjorn

7:31 PM

Björn = ACuriousMind

Then why not just say that in the first place?

I just like saying Björn.

And who uses @ A?

@Jimnosperm If @NeuroFuzzy changes to ACuriousJim

It will take over as the top A alphabetically in chat.

Doesn't answer my question. Who actually uses @ A for that to cause a problem?

7:32 PM

I do?

When I want to ping ACuriousMind, I do @ACuriousMind. It's muscle memory at this point.

Well be prepared for a problem then because the #1 name for next month is ACuriousJim

Hmm, not if I take it first. I can't ping myself.

Because there's no possible way of me choosing the same name and thereby allowing you to ping that name

7:46 PM

Wow, there is an unusually high influx of crap first posts. I've already flagged 9 today and LQ reviewed a few more

Gone are the days when only 1 or 2 new answers to old questions from new users would come through and need to be deleted per day

Not that I mind. At this rate, I'll have marshall by next month

Hey, do you guys know of a way to check new entries to many journals in one place?

You mean new submissions? New publications? Or just new material from across physics?

@0celo7 ACuriousAAA

Publications mostly, I am about to graduate and want a quick way to keep up to date with anything interesting. Any idea?

8:03 PM

@Pigeon If it's just keeping up with anything interesting, go to arXiv.org and sign up for email alerts with topics you find interesting

@Jimnosperm Hehehe :)

0

A: Does the universe follow a general physical and computational principle of evolution?

Is all stories. We live in a mostly non-linear mathematical world and most of our models/theories are linear. Fuzzy logic, FCM's are more appropriate in resolving complex issues. The math stories are usually easier to verify as to truth. No so for physics, except for the math parts.

I think I'm being too mean again

Veeeery interesting. A bunch of users have been removed, and quite a lot of downvotes on my posts have disappeared.

Someone really didn't like you

If you look at the recent meta posts, you can also see exactly who

8:07 PM

lol, GreenRay

@Jimnosperm And no, you're being too mean here, you're completely correct.

correct $\ne$ not mean

Also, did you forget a "not" or was I being too mean?

Canadians can't be mean. Genetically impossible.

@ACuriousMind up and down votes disappear if the users leave?

8:23 PM

@Jiminion Not if the user is of high ranking on the site. If the loss of rep from them would be widespread and great, the system leaves it. Otherwise rep is reversed

@Jiminion Your question makes no sense. I don't know what you're asking

@Jimnosperm It probably makes no sense for several reasons. One reason it makes no sense if one believes that infinite space is already 'there' and doesn't need to be created. I've read that many now believe that, but there was also a belief that mass/energy define spacetime with its presence.

@Jimnosperm Don't you remember being a newbie user? Not being able to comment feels wrong.

@0celo7 "who do I have to **** to get 50 rep?"

Exactly.

@0celo7 I do remember wanting to comment but not being able. Know how I handled it? I said to myself "I can't comment without 50 rep? I'm going to work hard to get 50 rep ASAP so that I can comment everywhere"

I didn't try to circumvent the obviously designed system, because I knew that ignoring the rules of the system disrespects the people that support that system, and that wouldn't go over well

8:33 PM

If you're not a troll, not being able to comment is incomprehensible.

I'm not a troll

@Jiminion no, the most confusing part is the "Is there any evidence that this expansion has a retarding force on the expansion?"

The rest is the product of misunderstandings

@Jiminion don't listen to that answer. Gravity isn't considered a force so much as it is the curvature of spacetime at that scale. And, while it does cause the deceleration of expansion, it also causes the acceleration of the expansion. So calling it the retarding force is not even wrong

@Jimnosperm I agree that one should work to get 50 rep instead of doing what that guy did. I won't accept that answer, but I gave him an uptick to now he has 50 rep!

Gravity isn't a force? And I don't think weak force is really a force. So that leaves EM and strong.....

I'm saying that the 50 rep rule makes no sense.

@0celo7 I'm saying I kinda agree with you, but OTOH, it's not hard to get 50 rep either. I'm not wise enough to question it, at this point.

My first thought was not "oh I better get 50 rep" it was "oh they don't want to hear what I have to say, wonder why"

8:43 PM

@Jiminion So what you did was artificially and undeservingly inflate his rep so that the intentional ban on new users posting comments didn't apply to him? Why have the ban in the first place if you just help him cheat the system?

The 50 rep limit prevents trolling, thank you comments, chattiness, etc, etc. All manner of unwanted commenting is reduced by the 50 rep minimum

@Jimnosperm Well, he wasn't wrong. He wasn't even wrong. Another guy made a similar comment.

@Jimnosperm His answer was wrong, but he helped me to clarify the question (as did you).

user54412

I just want to take this opportunity to remind everyone that we are losing

user54412

physics.stackexchange.com/stackegg/leaderboard

rationalwiki.org/wiki/Not_even_wrong

user54412

41st place on the network. That puts us behind Portuguese SO, Ebooks, and Coffee, which I didn't even know existed.

8:51 PM

What the heck is stack egg? (I could read the rules, but a simplified explanation would save us all some time)

user54412

You assume I read the rules.

You seem to care about it, so yes

user54412

Reading rules detracts from time spent winning

user54412

Certainly in the case of winning internet points anyway

Ugh, a removed user cost me 30 points. I guess I lost a bit of my lunatic fringe fanbase....

@Jimnosperm Woit has a blog named after this (he is dismissive of string theory).

8:56 PM

So I just lost 48 rep because a user was removed

Does that happen often?

I think today was a bad day.

@Sean no, not often

I was not amused

@ChrisWhite I think that's probably because not many of us are playing that game

Also, when I went after some chat flag, I discovered that some of the codegolfers seem to have a scheme to go on other sites and make deleterious decisions for them.

42nd now

What's it about?

9:01 PM

I think, as the name is meant to allude to, it is a "Stack version" of tamagotchi :D

I never got into Chinese cartoon video games.

@Sean I think your rep may have just gone up a bit....

I think tamagotchi was Japanese :P

@ACuriousMind This chat needs to learn 4chan lingo.

Anime = Chinese cartoons

Tamagoyaki - from 'Heroes' ?

9:06 PM

We've almost won the internet a second time.

Which would actually put us ahead of the StackOverflow Guys

@ACuriousMind Do you know why the most frequent tag is quantum-mechanics and not Newtonian-mechanics? On math calculus beats real-analysis

Where are the rules for the stack egg game? I'm so confused...

@0celo7 Because many laymen questions tend to be about the weirdness of the double slit/QM in general or similar, and because more students have trouble with Hilbert spaces and bras and kets and wavefunctions than with mechanics, I think.

@Sean There's a link if you click on the question mark at the top of the window.

@ACuriousMind I'm surprised we don't get flooded with non majors taking physics electives

9:12 PM

Now we're ranked 13

The math people get flooded with freshman taking calc

@0celo7 I think many of them are smart enough to look a bit around, see that their homework would be off-topic, and don't ask it.

At least, that's what my faith in humanity tells me :P

user54412

lol

user54412

19

Q: What is the optimal strategy for the launched site in Stack Egg?

The Stack Overflow instance in particular seems pretty poor. How should it be done to achieve the best performance? How is there such a difference between different sites?

You give college freshman too much credit

user54412

9:14 PM

@0celo7 Says the person who's not yet in college? :P

@ChrisWhite I'm pretty close man

I was going to migrate this to Meta, but then realized that it's technically a question about a video game AND about our engine, so it's on-topic for either. :) — Jaydles ♦ 5 hours ago

From another question on StackEgg

@0celo7 High school Senior? :-)

@DaveCoffman yeah

To someone my age, Phys.SE looks like a homework site

0

Q: If a vehicle (bus, train) rapidly stops (or accelerates, or turns), why don't our hair or clothes move from the inertial force?

Many times I was sitting in a train, watching closely nearby people. If the vehicle changes it's movement rapidly (brakes, turns, etc), then obviously, people feel the inertial pseudo-force that might even make them fall. They don't fall, however, since by the power of their muscles they keep th...

First sentence gives me the creeps

9:32 PM

@ACuriousMind He's probably a CIA analyst or something and he has to watch out for foreign agents.

What's more worrisome is that your first thought is that he's a stalker of some sort.

Figures, I guess.

@ACuriousMind is people-watching not a thing in Europe? Haha

@0celo7 Of course it feels confining and awkward and, as you say, wrong. But it is an absolutely necessary protection against a large class of low-effort trolls so there is no help for it. We need it to leave us enough time to deal effectively with the high-effort trolls.

1 hour later…

10:42 PM

@ACuriousMind That black hole question is a mess.

I tried to clean it up a bit.

I love how this

user image

is what he posted as an equation.

He didn't even bother zooming in XD

(I'm actually not sure that I got the exponent of $r$ in the sum correct.)

What you typed looks correct to me

@ACuriousMind Well, Jerry Schirmer has never seen the metric, so that does not bode well for the question.

@ACuriousMind BTFO'd Chris White...

@0celo7 You really make me feel old :P BTFO?

Jesus man...blown the fuck out?

...no meaning of "to blow out" that I know lets that make any kind of sense :P

10:55 PM

So you get a random joke about some archaic horse and wagon idiom, but you don't know what BTFO means?

I'm perplexed.

@ACuriousMind hey, btw I came across sth that may interest you, by E. Witten, he talks about how you can define path integrals as a trace without the vector space, here's the talk

urbandictionary.com/define.php?term=btfo

@0celo7 lol

@ACuriousMind Never heard of "blown out of the water"?

@0celo7 Now that you say it...

10:56 PM

And a quote from it (near end): "well there isn't a vector space here there's only an algebra, you see..., what we computed here, ... something that has all the algebraic properties of a trace but may not be a trace is equivalent to having a deformation of algebra of observables without the space that it acts on, other than itself."

Anyway, you crushed him. Destroyed his hopes and dreams.

@Phonon Why must you always send me interesting talks that are over an hour long? :D

QFT nerd telling the GR what is up in the diffgeo realm.

@ACuriousMind duuhh, because all the interesting ones are 1h+ ;D

@Phonon Can't it be a nice, short paper once in a while? ;)

10:58 PM

@ACuriousMind ah sure, will keep that in mind :D

@ACuriousMind Wait, did you actually know what nil and solv is or did you Google it?

@ACuriousMind My dad is designing a MOOC. They say the attention span of most people is 9 minutes...

@StanShunpike Are you looking for more on your $\Phi$ question?

That's based on tracking how long people actually watched lectures for before exiting

I think I answered it.

11:00 PM

@0celo7 I knew what a nilmanifold was (although I don't know where from). Could've guessed the solv one in less than three guesses ;)

30

Q: Fastest way to meet, without communication, on a sphere?

I was puzzled my a question my colleague asked me, and now seeking your help. Suppose you and your friend* end up on a big sphere. There are no visual cues on where on the sphere you both are, and the sphere is way bigger than you two. There is no means of communication. You can determine your r...

geometry puzzle game-theory spheres

Fascinating question. I'm not really satisfied with the answers!

@0celo7 Yes yes, I got it. I'm still confused about the Christoffel symbols though. See the problem is, I can't figure out how the indices are supposed to work in the definition of the Levi-Civita connection. $$\partial_k g_{rj} + \partial _j g_{rk} - \partial _r g_{jk}$$ and I just don't get how this is supposed to work. Are $k,r,j \in \lbrace t,r,\phi,\theta\rbrace$? If that's it, then I get it. Otherwise, I'm confused why we have different indices.

So I used this modified formula I found on this website.

Because I wasn't clear on that.

@StanShunpike Where did you see that?

What it means depends upon the author.

physicspages.com/2013/12/25/…

@Danu What doesn't satisfy you? That they all end up recommending you move more or less at random?

11:08 PM

@StanShunpike Ok, it looks like they use Latin letter for spacetime indices.

Yeah, they do, is that uncommon?

Yes.

If you read a math book, they are likely to use Latin indices though.

You should always check in the "notation and convention" in the front of the relevant book.

That's smart. I didn't think of that. But books very in quality of that.

Sometimes they do a really nice job, one book I had even listed the page numbers where they defined the symbols.

@ACuriousMind Yeah. I feel there should be something nicer!

My notation is early Latin for abstract indices, middle latin for spatial indices in physics, middle latin for all indices in pure math, early Greek for tetrad, middle Greek for spacetime, capital Latin for spinors.

11:10 PM

The one that suggests move-standstill alternation is decent

Pillars of Eternity is looking good btw, ACM

People are playing it on twitch

Wald uses capital Greek for spinor components...but I've never had to use them outside of his book, so I don't know what my preference is.

@0celo7 What's the difference between "early Latin" and "middle Latin"?

@ACuriousMind abc vs. ijk

@Danu I like it very much

@0celo7 Ohhhh! I was desperately trying to remember if the early Romans had a different alphabet than the later ones :D

@ACuriousMind Hah, I see what you were thinking about

^^that

11:14 PM

@ACuriousMind there you go.‌.. apparently this paper made Nima Arkani drop condensed matter physics and take on QFT seriously ;)

@Phonon Source of anecdote?

@Danu here watch from 0 to 2:25 mark

Danke schön

I think it's pretty retarded that people still hand-write presentations

it's acceptable when you're nima ;)

Doesn't Arkani-Hamed hand-draw the pictures in his papers? :D

11:16 PM

No it really isn't

He hand draws the text too

Pictures---okay

Text, no

Polyakov does this too

and it pissed me off a lot

when I was writing my bachelor's thesis based on some papers of his which he presented on

...with handwritten notes

:(

@Phonon Hmmm...I don't find renormalization all that fascinating (yet), so I'll give it a read ;)

My QFT teacher insists that the normal renormalization stuff is purely due to being careless multiplying distributions

(I think he's right, but don't really want to learn the "proper" way lol)

nvm lol

@Danu The "removing infinities" probably is, but the Wilsonian picture of renormalizing to get effective theories at certain energy levels has nothing to do with this, I think.

Yeah

He said it's not renormalization that's wrong but regularization

He said that renormalization is totally normal and classically happens in stat mech too

11:21 PM

yep, that's one way to solve the Ising model

@Danu I've heard that one before. If only I knew StatMech...

^so true

I've said it before: It's so shitty that my grad school refuses to do more advanced courses on topics that are also treated in undergraduate degrees at a more basic level.

@Danu That's a quirk of German universities that I don't fully understand, either.

@ACuriousMind it's never late man... here I'm in a generous mood :p

"generous mood"---gives link to Landau book

11:25 PM

hahah

The talk by Nima is on his amplituhedron stuff again

I'm pretty interested in that idea because of the geometric background

yeah I know, give the talk a go, maybe you ll like it

I am doing so :)

Btw, is the Landau book on stat mech really good? :)

yes, I really liked it

I use some others these days

but started off with Landau in bachelor, very satisfied with it

awesome

I really really should read at least 1-5

Not really interested in the fluid mechanics ones haha

11:30 PM

haha yeah, read the main parts of the first 3 chapters I'd say, it's an exceptionally easy read (not typical of Landau series of course...)

@Phonon Thank you :P

np^^

@0celo7 I also don't know that one. Never heard it online.

@Danu Really?

Second board I looked on.

« first day (1608 days earlier) ← previous day next day → last day (3322 days later) »

Transcript for

Mar '1531

The h Bar

General chat for Physics SE (physics.stackexchange.com). For M...

join this room
about this room

00:00

06:00

12:00

18:00

all times are UTC

site design / logo © 2024 Stack Exchange Inc; legal

mobile