The h Bar - 2013-07-10 (page 2 of 2)

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3:00 PM

In this case the re-merge is undoable, too. A merge is just like a rename here

oh, i remember now

@user1504 : I agree with @dmckee that this question could be closed as duplicate because the answers will more or less apply to both questions; and secondly, it should be closed because it is a list question; and thirdly, anyone could answer this by themselves if they thought about it for a minute, so the question is basically just noise on the front page.

@Qmechanic I don't object to it being closed as a big list question, or as too broad.

user54412

@Gugg I suppose if you believe your radar gun can accurately measure speed, then the width (in frequency) of the reflected pulse measures the velocity dispersion (i.e. rotation) of the object - but that width may be 1 or 2 orders of magnitude smaller than the offset

user54412

it must be quite a noisy measurement

But the applications of QM in technology can require more than surface understanding. If the answers to the "What are examples of visible quantum phenomena?" question also answer the "What are technologies that required quantum mechanics to develop?" question, then maybe we didn't do such a good job answering the first question.

3:15 PM

I've canceled the duplicate close at this point. I've gotten to where I don't understand exactly what the close reasons are in cases like lists and this kind of highly general reference question.

I want that question closed, because I see it as noise and because it has more that enough answers and people are adding silly stuff.

But my annoyance isn't a valid close reason, now is it?

It's probably an indication that there is a valid reason to close it.

@ChrisWhite I think I'll put it on the main site. Also, because I would think that the reflection of the sides (edge) of the ball must make it even more difficult.

@dmckee Broad. For lists.

Might also be reasonable to community wiki-fy all the answers

resists urge to post meme

user54412

3:25 PM

hmmm even wikipedia doesn't have a "list of quantum technologies"

lol

+1, I'd add two things: 1) Questions about non-mainstream physics should be ok, e.g. ("Have Podkletnov's antigravity experiments been independently reproduced?", "Why do we believe cold fusion can't work?"). Questions in fringe physics aren't ok ("Where does the square root come from in this mass-formula?"). 2) We should be careful about "questions that propose a new concept or paradigm". Those can be very useful, and generate research-level content, but they can also invite half-baked speculation (like "Are all particles the same string weaving the fabric of the universe"?) — jdm 3 hours ago

@jdm afaict (1) is not allowed, but I'm not sure. Regarding (2) That's actually OK. While the "one string to rule them all" question wasn't worded too well, it didn't fall afoul of the current non mainstream policy. — Manishearth 15 secs ago

thoughts?

Also, input on the nonmainstream meta post please :)

@ChrisWhite also, congratulations! You are one of the elite few with a meta-faq post to their name! :P

user54412

If Ron Maimon saw you trashing cold fusion like that... :P

(1) is what I'm unsure about

Can you ask why a theory is discredited?

Or what support a theory has?

user54412

interesting

For NM theories?

I don't think so, personally

user54412

3:29 PM

certainly "How did M+M disprove the ether?" seems legit though

because the ether is technically mainstream :P

Talking about the ether is like talking about newton's laws

both invalid, but were mainstream at one point and have their uses

user54412

speaking of anti-gravity, I just happened across en.wikipedia.org/wiki/Anti-gravity

user54412

most pseudo-scientific wiki page i've ever seen

user54412

mmm - i'd be okay with "how do we know this theory won't work?" since we could explain, e.g., "FTL travel implies time travel, which implies closed TL curves, which is just ridiculous"

user54412

the questions that ask for specific, experimental refutations are the problematic ones

3:36 PM

@ChrisWhite That's because the question is poorly bounded. Do we include or exclude technologies which were found before we understood the quantum underpinnings? What about things that could--in principle--have been found empirically? Meh!

user54412

no sensible experimentalist is going to spend money disproving something no one believes to be true

2

@ChrisWhite This. There has to be a reason to spend money, and some cranks "I think" doesn't qualify.

@ChrisWhite What? CTC is ridiculous? Hmph. All my childhood dreams, ruined.

user54412

@dmckee exactly, so if OPs demand experimental evidence against the theory, we have nothing to offer - such questions are of no use to anyone

Good point. May want to leave a comment to that effect

(or edit)

3:52 PM

@ChrisWhite (Cricket balls on main site now.)

Apparently @CrazyBuddy is a string theorist

(He used a Markov chain generator to fool his friends)

user54412

in some ways that seems more satisfying than actually becoming a string theorist

user54412

would that I could Markov chain my way through a dissertation

I could probably make a bunch of papers and tell my friends that I published 'em this summer. See how many actually read it.

@ChrisWhite dl.dropboxusercontent.com/s/y7c3hzoab7b15zm/…

user54412

I love reading these - they're always so well formatted too

4:07 PM

@ChrisWhite quickmediasolutions.com/flack

pastebin.com/PL6mcSa3

TP people (Dilation will shoot me) should pardon me for that..!

@ChrisWhite Apparently you're a research leader ^.^

But, I had to use a few physics parameters to convert a math paper to physics..! ;-)

@CrazyBuddy you may want to try flack overstow on your profile too

What?

4:10 PM

Flack Overstow

2

It's the markov chain applied to SE posts of any given user

Hah... That I'll try for my next b'day...

(Keep those comin') - I get a lot of reputation from my group :D

Let's see what Markov Lubos has to say

> A few conversion factors in there, e.g. Engine speed is normally given as any two molecules interact. You'd expect a long range attractive force and the nitrogen should get denser. However bear in mind that the torque divided by the gearbox (and differential) ratio. The diesel won't accelerate twice as fast as the petrol because it's so much heavier than the power is torque times engine speed.

> There are a few conversion factors in there, e.g. engine speed is equal to $\psi^2$ if the wavefunction in polar co-ordinates since these make it simple. So you just need to work out where $\psi^2(r)$ is analogous to the water flow rate. If all the water flows through the skin of the plane would behave very differently in practice. Your water wheel probably has an ideal your gas is. The specific heats of an ideal diatomic gas should have been a comment, but it.

John Rennie ^

Heh! Nice. How many prefixes are you using there? And are you treating punctuation as tokens?

@ManishEarth: It's Nathan Osman..!

I've seen many abt him ;-)

user54412

I like this answer of mine:

user54412

4:13 PM

> As "energy," so saying all other energy in any form adds to the sense that a better choice of nonlinear waves, let's ask what a value $\psi_1(t) = \sin(\omega_1 t)$ at $r = R$.1 With this in the world at the time. It may also help to remember that statement only holds in a reference frames.

@dmckee Hm? I'm using Flack Overstow, not written any code myselg

lol

> Dropping a lower electrostatic potential level. By demanding that this is minimal – are the mass terms which aren't "characteristic terms" of the strong interaction. However, they're still parts of the point of the jump, and its complex conjugate that make all quarks which is substantially weaker than the effect is that their density isn't quite necessary for the seesaw mechanism for neutrino masses.

> Quite on the words were should be translated as the spacetime topology. We demand the correlation function is negative. In quantum randomness is here to stay and by the 7-4 = 3 MeV is much smaller than the typical QCD mass scale, 150 MeV or the Planck scale which is huge and at these short distances or so if we approximate the number of operators are known as the new GR book by Anthony Zee, imagine that a boy on the magnetic moment proportional to the spin.

Ah, I'll look there. I would guess that punctuation is a token and n=3 or more.

^ Lubos

@dmckee yeah

@CrazyBuddy yep. = George Edison

> At which electrons leave the cell and finding their total mass. In reality, configuration of 1 year orbital period for both planet and satellite doesn't just cut the onion or meat or whatever food, but it's also the altitude where there's density variations in atmosphere, etc. Googling on this, we dump our thought that cathode depending on the direction of current orbit (at a distance of 0.00255 AU having orbital period of 27 days) to the 1-year orbit (at some relative motion $v$).

> After some factor). After plugging several things from Wiki... Loudness, a subjective measure, is that aluminium foils are designed in time. There's no preferred reference frame and a physicist can tell how bad the bomb is. This Wiki article quotes it... The amount of the gauge at entry to the wind (which can be found using mass spectrometers. The assumed mass is $0$. Because, always keep in mind.

I guess I'm always talking about celestial mechanics :P

Doing yourself is a little creepy: you recall writing bits of what you see.

4:17 PM

yeah

I know..! But, it always "lol"s ya know...

Me:

> I can't say if that is just another kind of energy (previously you had to worry about kinetic energy of the components and their ten minute halflife they are able to measure the dilation to exceedingly high precision. Many features of relativity you have to add mass to the neighborhood of 100 MeV (which is the parameter of time dilation) and the theory has worked superbly, giving us no reason to doubt it.

I'm such a blow hard at time.

@dmckee Hah... You're always like that :D

(But, I always like the way you comment):P

user54412

---
eventually I'll construct a data.SE query to determine which textbook authors generate the most questions on this site

user54412

I think Wald has to be near the top of the list

4:26 PM

@ChrisWhite won't be hard

Oh my God @Chris, these criminal people have infected you too..!

I'm all alone now..! :P

user54412

@ManishEarth says someone who already knows how to query a database

(One day, that H-Foobar changed everyone here)

@ChrisWhite No, seriously, it's not. SQL is quit easy to learn :)

Where's that Shukla guy or whatever his name..? If he ever gets here, I'll kill him..!

4:28 PM

@CrazyBuddy He's already part programmer. And part visible-light-theoretician, but don't mention that in front of him :P

@dmckee We of course aim at the very best service, but pragmatism goes a long way. Speaking in general rather than just the case at hand, if a question should ultimately be closed in any case, it might actually be the most merciful option to close it as a duplicate, if at least vaguely applicable, since then it gets linked to possibly helpful other posts, rather than just closed, leaving OP with nothing.

4

Yeah..! And, he didn't accept my request for visible-light synonym...! Grr...

@Qmechanic true

@CrazyBuddy ? visible-light ---> ??

1 sec... I actually forgot what I had given him :P

@ManishEarth Sorry... it was actually "eye" --> "vision" :D

ah

4:36 PM

Jul 7 at 5:55, by David Zaslavsky

@CrazyBuddy nah, I'm pretty sure eye can be merged into vision. Then we figure out what to do with vision

k

user54412

lurking on academia, I just saw this:

user54412

7

Q: Charging graduate students for printing

My university is starting a policy where graduate students need to pay for printing (10 cents per page) while It was free before. As a student coming from another university, I see it very weird policy. Actually, I am not aware of any university charges its PhD students for printing. I heard facu...

research scientific-productivity workplace

user54412

Am I terrible for now wanting to go into my department to print stuff for free?

user54412

(we used to be charged, but then nobody paid their dues so the powers-that-be gave up on that front ;-)

4:45 PM

Every time I see the "I am not a lawyer" acronym, I think of a caveman declaring how retentive he is. — Esoteric Screen Name 3 mins ago

@ChrisWhite Free printer for us, but they don't let us use the scanner o.o

5:24 PM

I just realized that my python program is going to be a bunch of os.system() calls -_-

@ManishEarth: Roughly, I can bookmark anything... Isn't it?

yeah

Tomorrow, I'm gonna reveal that I'm using the Markov. So, instead of giving our h-bar straightaway... I thought of giving the bookmarked convos only..!

doesn't make a diff

Only intelligent people will peek into h-bar and I'm quite confident that very few are really curious ;-)

5:51 PM

Hi @crazy

hey @Chris @Manish

hey

wats up how u doin

Hi @Rajesh ;-)

@ManishEarth I think why a theory is discredited or what supports it from a mainstream physics point of view should be ok here.

@Dilaton Should be != is

Thing is, if we allow that, then that's a potential platform to pitch a non mainstream theory

For example, if I was a kook, I could post "What if neutrinos were cupcakes? What is wrong with this theory?"

But you're right, some of these may be OK

I just don't like blanket allowing them

Tone matters here, I guess

If it's a pitch, delete

If it's an apparent paradox (like an "This system seems to give me perpetual motion. I doubt that should happen..."), then that's allowed

The trick is wording it correctly

So, IMO some of those questions are OK.

It's an "I know it when I see it" scenario, but hopefully I can think of a way to word it

6:15 PM

Okay... Everyone are forcing neutrinos to be cupcakes..! today :D

yesterday, by Chris White

This is tricky - we want to exclude people from proposing their own theories ("neutrinos are really cupcakes!!111!") - while still allowing people to ask "Is this theory I heard about on solid ground?"

yesterday, by David Zaslavsky

BTW now I want cupcakes :-/

yesterday, by Gugg

neutrinos are really cupcakes!!111!

4 mins ago, by ManishEarth

For example, if I was a kook, I could post "What if neutrinos were cupcakes? What is wrong with this theory?"

Crazy people..! Is this h-bar? All are stalking neutrinos just because they want cupcakes

@Dilaton FWIW, the meta post explicitly mentions that asking for evaluation of a new concept or paradigm within the framework of physics is OK

There's a difference here, though

Cupcakes have integer spin.

For new paradigms, you can say "within the framework of modern physics"

For new theories, they probably contradict the old theories, partially, and you can no longer do that

A theoretical answer to these can always be refuted with "but my theory doesn't care about that"

(for example, "but my theory doesn't consider energy to be conserved, so your argument is invalid")

An experimental answer, well, as @dmckee said, experimenters don't waste their moolah on kook theories, not usually

Chat is the best place for this imo

@ManishEarth yeah, I think certain things can be decided from case to case too, in addition to having a base rule about not allowing non-mainstream physics.

@Dilaton However, could you give me an example of a good, answerable and constructive question that does this?

ShuklaSannidhya

6:20 PM

If a bullet is fired from a moving car then will its velocity be different from its actual muzzle velocity?

Mind you, NOT a question that asks for an evaluation within M physics

A question that proposes a new theory and asks for experimental evidence

@ManishEarth well, each new proposed theory should first of all correctly reproduce the well known facts, theoretical and experimental ones. If for example a new theory contradicts special relativity, it is no good right from the start and this can then for example be explained in an answer.

@Dilaton Not really. As long as it predicts the same experimental results it is OK. It's fine to contradict relativity

ShuklaSannidhya

@ManishEarth ?

For that matter, any new theory will contradict established theory

in part at least

@ShuklaSannidhya relative to?

if the ground then yes

muzzle velocity is relative to the gun

6:26 PM

@ManishEarth now, new theories should not contradict established theories in their domain of validity, they should encompass and extend them to new for example higher energy regimes, and make new predictions there. Contradicting relativity is equivalent to contradicting experiment because there is no experiment so far that contradicts relativity or QM too.

No. I can contradict relativity without contradicting experiment.

@ManishEarth how?

Not sure exactly, but it seems obvious to me

For example, relativity contradicts newtonian mech to its bare fundamentals

yet it conforms to the experiments within the degree of acceptability

Same thing here

Either way, that's all hypothetical

@ManishEarth relativity incompasses Newtonian mechanics as its low velocity limit, this is not a contradiction.

@ShuklaSannidhya Yes.

6:30 PM

That is what I mean when I say new more general theories (relativity) should encompass the older more restricted in their domain of validity ones (Newtonian mechanics).

kk

There are for example people who say LQG is no good as a quantum gravity at all because by postulating fixed smallest length scales it violates Lorentz invariance and therefore special relativity.

@ShuklaSannidhya But @ManishEarth's reply is wrong, because he's out of his domain of validity.

But this is not so a good example ...

@Dilaton yeah, I was thinking along the lines of that

For example, Lorentz invariance is a core postulate or SR

And the aether is similarly a core concept of classical

as is the definiteness of the world

6:34 PM

@Gugg are you teasing me or Manishearth :-D ?

@ShuklaSannidhya The density of the air in the barrel will be higher, and therefore the bullet will have more trouble speeding up. How much more trouble, I don't know.

@ManishEarth yeah and the aether establishes a prefered reference frame which is against relativity too.

@Gugg I think he's neglecting that

@ManishEarth I think you are neglecting that.

I am

I mean that I think he meant for us to neglect that :P

6:38 PM

@ManishEarth how exactly did you generate that funny joke paper with Chris White and colleagues? I am only able to generate a screwed up abstract for my profile, but not a whole paper ... :-D

ShuklaSannidhya

Whoa!

@Dilaton thatsmathematics.com/mathgen

3

@ShuklaSannidhya You're not planning a drive-by shooting, are you?

@ShuklaSannidhya Buh !

@ShuklaSannidhya Because, if you're firing sideways, it might be different again.

6:42 PM

Haha, here is one. Test :-)

Darn :-( ...!

@ManishEarth Holy cow, that's fabulous!

@Gugg :)

Anyway, maybe I should ask something at MathOverflow about Manishearth's and Chris's Paper :-P

thatsmathematics.com/mathgen/…

ShuklaSannidhya

@ManishEarth err... WHAT? So that N > L paper was phony?

I DIDN"T EVEN....

6:47 PM

Um, yeah, obviously :P

(a) It had my name and Chris' name on it.

oh, sarcasm

@ManishEarth LOL thanks :-D, that was such a hard work !!!

nvm

-_-

ShuklaSannidhya

@ManishEarth I should kill myself... after killing you...

i'm doing like 5 things at once here, no time to look for sarcasm :P

@Dilaton Top of page 4 of your paper: How do you get a set to be less than a scalar?

ShuklaSannidhya

6:49 PM

> professionally formatted nonsense

great...

@ShuklaSannidhya Bazinga

@Gugg that's trivial ..! Which part of it do you not understand ... :-) ?!

@ManishEarth So, what are the chances of this thing actually producing something correct and ground-breaking?

@Gugg Infinite monkey theorem

I mean math, not Hamlet.

2

ShuklaSannidhya

@ManishEarth How did you add that "abstract"?

6:53 PM

@ShuklaSannidhya LaTeX.

ShuklaSannidhya

great... It looks so legit...

@Gugg A lot of modern math is focused on creating new symbols, juggling them a bit, and then partying when you get a result. A result that's meaningless because you started off with some random symbols. I'd say that Hamlet's harder to produce.

:P

Jeez, we could fill the whole internet (Lebesgue measure) with these papers!

(no offense intended, I like math )

@Gugg flood it!

You can use these to check how well the peer review at a journal really is

use a pseudonym

Then, identify the most lax (yet reputed) journal, and publish your own kook theories

And, our ancestors, what would they think when they excavate the internet then?

6:56 PM

@Gugg you mean progeny

/descendants

Yup, same thing, time-invariance.

@Gugg I bet half of those Egyptian tablets and Babylonian steles/bas-reliefs are basically our ancestors trolling us

Here is another funny trolling paper that made me rolling on the floor when first reading it insti.physics.sunysb.edu/~siegel/parodies/stuperspace.html ... :-D. And there are other joke papers too. They are so funny that I am sometimes not sure if this guy is serious about the other things he has on his homepage :-P

Could we possibly fool MO with one of these papers?

@Gugg alert me before you do it ... :-D

7:05 PM

Like: "They say the proof of theorem 6 is trivial, but I can't find one. How is it done? Please help, I'm on a deadline."

Ulysses S. Grant #10036.'

LOL

ShuklaSannidhya

> where ☎ is the telephone operator

@Dilaton Ohh... you didn't notice me..!

Fooling around...

3 hours ago, 27 minutes total – 46 messages, 4 users, 2 stars

Bookmarked 1 hour ago by Crazy Buddy

@ShuklaSannidhya yep :-). And in a follow up paper the say in the acknowledgement just "Thanks God it is Friday" :-P. Unfortunately I dont remember which one it was ...

@ManishEarth @ChrisWhite: So, I wrote a whole page of "pardon-me" conclusion inside the group (as a group admin)

7:20 PM

@CrazyBuddy LOL cute one :-D

pastebin.com/wjchXDpU

I unforunately missed your talk in Korea about it :-/

Ohh.. you didn't come..! You missed the whole entertainment..!

Everyone had gone CRAZY :D

Older version --> revised to pastebin.com/hrSsW9mq (Fooling around)

@CrazyBuddy you know, you can take screenshots :P

I know... But, Pastebin can reproduce when I need it..!

(I used it to produce it to another group at noon itself) :P

@ManishEarth: Any way we can include extra bookmarks hanging somewhere else..? :/

7:30 PM

@CrazyBuddy as in?

For instance, I had bookmarked something... I want to include a few more transcripts (separated by a lot of transcripts). Can I do that?

I just produced a paper on quantum graph theory. Does such a thing exist? (Really interested!)

@ManishEarth: Okay.. I want to include my "Conclusion" pastebin into the bookmark... Can I do that? No? :/

nope

8:05 PM

So, you guys and gals ready for some cricket?

6

Q: How do they measure the rotational speed of cricket balls?

The 2013 Ashes series (a cricket thing between England and Australia) are underway as of today and it seems they have a new (to me) gimmick. It appears that they are now able to measure almost instantaneously (within a few seconds) the rotational speed of balls bowled by spin bowlers. On the (...

everyday-life sports radar

@Gugg Are we going to need cricket?

Yes.

Or balls, since you seem to like questions about them, cricket, baseball, or otherwise

How many questions does SE need for a tag?

Physics.SE? Probably ~10

But there are other criteria for good tags too

8:09 PM

How about a gugg tag?

lol

Actually, I believe all other questions are off-topic.

And I'd love to have my own tag. Would that be a novelty?

@Gugg you probably can get our own subreddit

That's beyond my scope of validity.

What happened to the star board? O_0. Neutrino cupcakes are waay more star-worthy than the nonsense I spew.

8:24 PM

Looks OK to me. Cupcakes will return eventually.

8:34 PM

8:52 PM

Hi guys.. am I allowed to make a question on a physic problem that I'm trying to solve since this morning failing?

21

A: How do I ask homework questions on Physics Stack Exchange?

What kinds of questions are considered homework questions? A "homework question" is any question whose value lies in helping you understand the method by which the question can be solved, rather than getting the answer itself. This includes not just questions from actual homework assignments, bu...

@newbie Depends, read that ^

thanks for the link, I'm reading it, btw it's not homework, it's an exercise that I can't do in my yesterday physic test.

We don't distinguish

ok, thank you. Goodbye

David Zaslavsky

9:42 PM

BTW @CrazyBuddy no word back from AstroBites yet

@DavidZaslavsky Hey, 24 hours are up, want to lock in the close reasons?

I added the links (have a look at that too)

AstroBites?

David Zaslavsky

For a community ad

We wanted to get permission to use their logo

ah

10:10 PM

@DavidZaslavsky has being a moderator here helped your research in any way? As in: relaxing? a catalyst for new ideas? increased your contacts who can help you with your research?

David Zaslavsky

10:23 PM

@LarryHarson Begin a member, sure, but being a moderator? Not particularly.

Yeah, I doubt that modship gives any extra benefit

Though you get to know a lot of nice people in TL :)

1 hour later…

11:46 PM

1. http://i.stack.imgur.com/AUwYh.png
2. http://i.stack.imgur.com/lC8oH.png
3. http://i.stack.imgur.com/Eb9XY.png
4. http://i.stack.imgur.com/36AmR.png

@ChrisWhite SUCCESS!!

Each one took a looong time to generate, but success!

(i used a different input file I downloaded. Turns out that the main issue was that I just wasn't asking it to be accurate enough -- at the time the calculations were taking long enough, so I wasn't sure whether or not to make them more accurate)

user54412

@ManishEarth oooh those are pretty

user54412

meanwhile I just discovered the terrible source of all my frustration for the past several months

user54412

the classic paper in this field that everyone cites - well, its numerical methods are faulty >.<

I also wrote a bash script in python that makes life easy when I want to make these graphs (and it's quite easily extended to other applications

Yes, you heard that write, a bash script in python

(It's basically full of os.system()s, but I wanted to use argparse :P)

user54412

argparse is beautiful

11:52 PM

@ChrisWhite Is that your discovery or was this known and they decided not to tell you? :P

@ChrisWhite Yeah :D

user54412

no one has so far had the decency to tell me about this ... so I guess its my discovery

Publish it!

What do you mean faulty, exactly? o.O

user54412

oh i'll publish something alright

Seriously, though, if there are faults in a widely-cited paper isn't it standard to publish that?

user54412

basically, the method revolved around finding a root in the complex plain, and it used a primitive numerical technique that was apt to converge to a false root

user54412

11:55 PM

well, astro papers are often a mix - theory, numerics, and/or observations

user54412

the community has long since moved past the physical subject matter of this paper (it was doing a linear analysis in a field that went fully nonlinear years ago)

@ChrisWhite ah. that woul be hard to notice

user54412

so the only thing wrong is the technique, which is what i was using in a slightly different physical context

ah

user54412

lesson learned: never trust numerical algorithms from back in the day

11:59 PM

ha

user54412

also, I thought having a copy of Numerical Recipes on my desk at all times was enough - but really one has to keep a copy opened to the most relevant page at all times

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