The h Bar - 2017-01-22 (page 2 of 2)

« first day (2271 days earlier) ← previous day next day → last day (2641 days later) »

AccidentalFourierTransform

7:48 PM

1

Q: Clarification on infinite mass/momentum argument

While reasoning that why a particle can not be accelerated to light speed $c$, it is argued that the mass/momentum approaches infinity as speed approaches $c$. I think it is per GR. I am sure this also fits into mathematics, otherwise people would not be making this argument. I may be wrong, an...

special-relativity mass speed-of-light momentum

does anyone understand this question? ^

sigh

it seems OP just can't leave this one alone

Bernardo Meurer

Isn't that the guy who told JR to die?

@BernardoMeurer dunno

it was a ridiculously contentious question at the time

huge amounts of back and forth

set a bounty, awarded it mistakenly, and then tried to unaward it to put it somewhere else, or something like that, as I remember

OP has now (almost three years later) unaccepted my answer and accepted another one

... plus side is a gold populist badge? I guess I'll take it

Bernardo Meurer

Sigh

What a pain in the ass

See, cotangent space is also a vector space and it can be thus represented in terms of components as a column vector, just like any abstract vector space and thus it will transform like any other vector does. ALL VECTORS ARE THE SAME IN TERMS OF HOW THEY TRANSFORM. — Isomorphic Mar 28 '14 at 16:36

that sort of tone

anyways @Bernardo, got any experience setting up Jekyll on Windows?

Bernardo Meurer

8:05 PM

@EmilioPisanty Not on Windows, but it should be straightforward. Install Ruby, it should come with Gem, then just do gem install jekyll and it should work. Use Powershell and maybe you'll need to find out where gem puts it's files in Windows and add that to your PATH

@BernardoMeurer I think I got it, but it wasn't that straightforward

kept saying something about a devkit something something

Bernardo Meurer

Hm, interesting, how'd you fix it?

@BernardoMeurer this was the clearest jekyll-windows.juthilo.com

but I think I ended up using some other installation

Bernardo Meurer

Interesting, do you run Windows as your main OS?

Lack of UNIX compatibility makes it misbehave with devtools sometimes

@BernardoMeurer on this laptop, yes

8:11 PM

@BernardoMeurer Didn't I read that Windows 10 now has a fully POSIX compatible interface? Or are you wisely sticking with an earlier system?

work desktops I run on ubuntu

@dmckee it does, but it feels disconnected from the rest of the OS

Bernardo Meurer

@dmckee Windows 10 supports an Ubuntu subsystem, which I gladly hacked into an Arch subsystem

I do run Windows 10 on my dualboot, but it is barely touched nowadays

The Linux Subsystem on Windows is actually pretty usable

::sigh:: so jekyll is working, but jekyll -watch is not.

Bernardo Meurer

Honestly, try the linux subsystem

@EmilioPisanty You're in luck, the Windows guru has come

@JohnRennie Help this poor soul

@BernardoMeurer I'm already bouncing between different versions and installations of stuff

it's working OK out of powershell

it's just not doing the --watch thing

@JohnRennie, any experience with Jekyll?

8:27 PM

I don't even know what Jekyll is I'm afraid.

@AccidentalFourierTransform On a couple of readings I figured it out. The author simply doesn't know what he's talking about.

I started with a couple of comments, but in the end felt I had to write an answer

0

A: Clarification on infinite mass/momentum argument

The question is founded on an incorrect assumption. The math absolutely is symmetric between acceleartaion and deceleration (because velocity enters in to the Lorentz factor squared), and we have machines that take advantage of this fact. Energy recovery linacs work in exactly the manner linacs...

AccidentalFourierTransform

@dmckee lol, let us note that the exact same thing can be said about most questions tagged speed-of-light

@JohnRennie website building engine

lets you do things like jekyllrb.com/docs/datafiles

<ul>
{% for member in site.data.members %}
  <li>
    <a href="https://github.com/{{ member.github }}">
      {{ member.name }}
    </a>
  </li>
{% endfor %}
</ul>

Bernardo Meurer

I hate ruby almost as much as I hate fonts

meant to be good for GitHub pages

@BernardoMeurer fonts as in what microsoft word has?

Bernardo Meurer

8:37 PM

Yes

But not only MS fonts, I hate all fonts

I hate OTF and TTF

I hate fonts

AccidentalFourierTransform

@BernardoMeurer well I'm fond of them

Bernardo Meurer

It's not their looks, it's how their handled in Linux

It drives me absolutely nuts

@BernardoMeurer then it's not fonts that's the problem, it's linux

Bernardo Meurer

You must be ambitious when you hate

fonts is, like, a system requirement

if a computer system cannot do them correctly, then the computer system ain't up to scratch

Bernardo Meurer

8:40 PM

No it ain't, you can do fine with 8 bit fonts :P

it's like saying that a computer system is fantastic, except it can't do saving files

or some other arbitrary restriction

I dunno, dealing with filenames with spaces in them, or something equally bizarre

'cos, I mean, who'd want that?

Bernardo Meurer

I'd be up for not allowing spaces in filenames

@BernardoMeurer 'cos who cares about usability?

this is why we have designers design things instead of engineers ;-)

Bernardo Meurer

I will not aid my user in engaging in bad practices :P

8:56 PM

I want to put up a billboard in front of a busy highway that says

> There are no amateur physicists anymore!

4

Even the self-funded tinkerers have to put in the time and dedication of a professional to actually accomplish anything.

But people just don't get it.

@dmckee ever wander into the quant-ph section of vixra?

@EmilioPisanty Hell no.

@dmckee it's an instructive lesson into the time and dedication that some amateur physicists are willing to invest into their craft

seriously, have a gander at the abstracts

vixra.org/quant

and tell me if you notice anything particular

I have colleagues who gleefully plot a campaign to see as many of the kookiest of crank talks at he end of a APS meeting as possible, but I don't get what they find entertaining about them. They make me sick with pity for those poor sucker.

@dmckee I went to several such talks two years ago

I found them very instructive tbh

9:02 PM

Oh. My. God.

@dmckee what?

finding crank talks instructive?

@EmilioPisanty I sit through the ones at the end of my sessions out of a sense of duty.

Thousands of papers per month, and most of them from just a few single authors?!?

or a certain author over at vixra?

@EmilioPisanty No. Just the string of single-crank papers.

@dmckee which month is that?

9:04 PM

I have to wonder if some of those 'people' aren't markov chain programs.

2

note that the numbers in the thousands at vixra.org/quant are just month identifiers

I'm looking at the link you posts. So this month.

i.e. 1101 is just 2011.01

Oh. Misread that. Tens of papers.

@dmckee that's not just this month. oldest post is september 2016

9:05 PM

Still pretty scary when we look at the number of them that share a single author.

monthly tallies up top, highest monthly is 79, I think

don't know what it comes down to if you remove the George Rajna papers, though

24 non-Rajna papers for 2016.11, I think

Why are you looking at Vixra

3

You crazy people

@Slereah because it's important to have at least a vague sense of what does and does not happen over there

Well some papers over there are crazy on the cover

Others sound like they could be reasonable but it's hard to gauge without reading them

and to be honest, I think Philip Gibbs has some very good points over at quora.com/Are-there-any-serious-papers-on-viXra

9:08 PM

@dmckee you have a point, but (to play devils advoate) there are many amateur physicists out there & some of them have real talent. also suggest that vixra is not 100% trash. there is an old zen koan about it. also heathers dad is interested in farnsworth fusion where there is a lot of amateur activity, some of it significant/ respectable.

Well vixra is like panning for gold

You'll find a lot of garbage

having said which, having a look immediately reveals that the overwhelming majority on quant-ph is by a single guy

@Slereah yeah, but to actually be able to say that, you need to actually have a look ;-)

Oh I looked plenty of times

there are a lot of crazy papers on arxiv, nobody has a monopoly on that... do not like some of arxivs hidden/ opaque editorial policy... (some discussion of this in old chat transcripts here)

though of course to really know you'd need to do a full review of many papers

Well there are some crazy papers on arxiv

Not that many tho

The crazy papers on arxiv are usually normal scientists who also have crazy theories

vixra just has a lot of cranks

I remember a vixra paper about a theory of everything based in hindu mythology or something

9:12 PM

@Slereah To be crazy on arXiv you need a constructive history in the discipline or the right institutional affiliation and you need to not come to the attention of the administrators. So you can only post so many things and they can't be obviously unfounded.

"The theory of idealiscience is an accurate theoretical model, by the model we can deduce most important laws of Physics, explain a lot of physical mysteries, even a lot of basic and important philosophical questions. we can also get the theoretical values of a lot of physical constants, even some of the constants can not be deduced by traditional physical theories, such as neutron mass and magnetic moment,Avogadro constant and so on. "

example of a crazy vixra paper

The cost of that is, of course, the possibility that someone with something genuinely new might not be able to put their preprint on arXiv.

I mean, you can see the point of the people who want open access even while being aware of the mire on vixra.

Deriving the avogadro constant sounds p. crazy to me

well you can't have it all

that's always the problem

AccidentalFourierTransform

vixra.org/abs/1207.0031

lol, have a look at the last page, before the references

under (IV) COMMENTS

"inviting the robe"

9:14 PM

>John Duffield

aaaaah

AccidentalFourierTransform

I rest my case

I'm not that worried about missing out on great geniuses because I don't think that nowadays, most science really hangs on the shoulder of a single man

Everything is a continuation of previous works in some way

@Slereah That's been true for nearly forever.

sure, but back in the days, you could just start a whole new discipline

AccidentalFourierTransform

Philip Gibbs - inactive, England, United Kingdom

7.2k 18 27

general-relativity energy-conservation cosmology conservation-laws energy special-relativity string-theory

9:17 PM

And if you didn't, it might be centuries before someone else does

Imagine math without Euclid

He was the guy that made the notion of proof popular

before that era math was all just cookbooks

these days though

I'm not sure anyone is really that important

I think we would have been fine without Einstein or Feynman

Maybe it would have taken a bit longer, but not that much

@Slereah cranks tend to be very identifiable/ recognizable/ standout in some ways such in their fixation with stuff that is widely thought/ recognized to be impossible by experts eg squaring the circle, P vs NP, riemann hypothesis, or deriving fundamental physical constants, something even experts wish they could do/ aim for, and can be pointed as a deficiency of modern sprawling-yet-still-incomplete standard theory etc...

One thing I notice a lot about cranks is the typesetting

A lot of cranks do papers in microsoft words

AccidentalFourierTransform

BECAUSE THEY LIKE FONTS

"Quantum gravity and comic sans, an essay"

I think I even saw a few handwritten papers on vixra

Or maybe it was just hand drawn diagrams

@AccidentalFourierTransform The picture on page 3 is golden.

> As a desperate measure to bypass the problems attempts are made to build a mighty String castle in the clouds.

AccidentalFourierTransform

9:20 PM

I once saw a paper with one page of physics, and three pages with the autobiography of the author

Keep in mind that only a few things in Newton's Principia were genuinely new—universal gravity and the beginnings of calculus basically (which is huge)—"Newton's" law were sifted from a mess of alternative that were around at the time: he just put them into a coherent form (again big, but he was standing on the shoulders of giants, after all).

AccidentalFourierTransform

and then a picture of the author by the fireplace

@ACuriousMind That's some Secret grade diagram

you also get this sort of stuff

I have produced this paper. researchgate.net/publication/… There is the 1/c unit explained. My G unit derivation seems to have more problematic, and might be wrong, at least it doesn't come out with same resutls if Imperial units are used. The fact, that 1 kg air is ~1 m3 might be the reason for that the idea works though. — JokelaTurbine Jan 19 at 11:31

how many cranks are working on merging QM + GR, officially/ widely recognized as a major aim for the field? even greats/ nobel prize winnders such as Einstein/ 't hooft etc are regarded as somewhat like cranks in some of their unproductive meanderings... its a very fine )( line sometimes... another remarkable example is grothendieck vzn1.wordpress.com/2014/11/26/…

9:21 PM

right here on PSE!

yeah cranks never try to do like

"Computation of the cross section of a J/$\Psi$ collision"

That's not a catchy crank paper

3

Or "Generators of some random Lie group"

Thierno M. Sow's papers are relevant

The thing about Einstein's unproductive wanderings is that he could be convinced he was wrong (or often convinced himself), and didn't announce half-baked ideas as breakthroughs.

4

AccidentalFourierTransform

user image

Also I think it's slightly unfair

9:23 PM

To my mind that is the most reliable marker of the difference between a scientists working on a long shot and a crank.

It's easy to qualify them as unproductive wanderings by knowing what we know today

@dmckee which reminds me of the complicated history of the cosmological constant... found a nice recent essay on that somewhere...

@AccidentalFourierTransform It's a beautiful mighty castle!

I also like the upside-down bird going ??!!! and the cat in the box

There's a lot attention to detail in that pic

@vzn Assuming that dark energy has the form of an Einsteinian cosmological constant that is a funny story.

@Slereah exactly. have long thought cranks are like "moths to the flame" :P ... yet they do seem to have a sometimes-uncanny attraction to finding the flame...

AccidentalFourierTransform

9:25 PM

lol, the bird...

Bernardo Meurer

user image

@dmckee How do I do this?

Cranks tend to be people of poor science education so they only know what they read in the press

they never read about actually popular science topics, ie mostly boring stuff

@Slereah wait you mean pop science is bad? :P

@BernardoMeurer I don't know. Star-delta?

They don't read the millions of boring papers about cross sections of various theories

9:27 PM

Circuits is not my strong suit.

Bernardo Meurer

@dmckee Mine neither, I'm trying to help @0celo7

there are a few nobel prize winners that are widely regarded as cranks... so anyway the topic is rather gray/ multicolored/ multidimensional, far from black & white... maybe more than 50 shades of gray :P

They're not cranks, though

They have

THE DISEASE

Famous physicists get it when they get old

they get the notion that anything they say must be gold

even if they only kind of know the field

@Slereah lol have you seen the xkcd on that?

I mean, you could always launch into a straight Kirchoff's laws approach, but it will be a big system. Reducing it a little would help.

9:29 PM

No, not xkcd

SMBC

smbc-comics.com/?id=2556

Obligatory SMBC

dammit, ninja'd

~~xkcd~~ SBMC lol oops got my geek cartoons mixed up thx for the help o_O

Well xkcd had a similar cartoon

^ That's one I don't put on my door, but keep around in hard copy to show some of my students when they get cocky.

user image

user image

9:31 PM

I have mixed feeling about the XKCD "Physicists".

For the purposes of spherical cow modeling sometime we really do know something worthwhile even though we've just arrive.

@dmckee has the disease!

But mostly it will just turn out to be a mathy way to say something that the experts in that field have known for decades.

Quick in the cage

Bernardo Meurer

How can one use Kirkhoff when there's no info on currents or voltages?

@Slereah As long as it is a nice cage with fast WiFI.

9:34 PM

that is called an office job

6

@BernardoMeurer hint just write out the equations with some variable for unknowns

@BernardoMeurer add a source on the left

with some unknown voltage

and solve for the current on that source

@BernardoMeurer Assume $V$ across the terminals and launch into it. But it's a big matrix unless you reduce it somehow.

that will give you the equivalent resistance, which is what you're after

Bernardo Meurer

@0celo7 Hope you're reading this

9:35 PM

@dmckee it's a painful problem no matter what

@BernardoMeurer What's "Kirkhoff"? :P

AccidentalFourierTransform

vixra.org/abs/1111.0100

"Department of Theoretical Physics, Yerevan State University, Yerevan, Armenia"

Bernardo Meurer

@ACuriousMind What he wrote me, lol

@ACuriousMind that's Kirchhoff in Danish

Bernardo Meurer

I thought it was Kirchhoff, but didn't want to alter the original

9:37 PM

@BernardoMeurer sometimes the unknown quantities cancel out in the algebra steps

@vzn of course they need to. You're just solving for the equivalent resistance

@ACuriousMind a new interpretation (so am sure youll luv it) :P

@dmckee I had this on my office wall for a long time

user image

I think I'll re-print it soon

really captures the thesis-writing-but-not-quite-deadline-panic spirit

AccidentalFourierTransform

user image

That's me everyday, @EmilioPisanty

9:43 PM

You spoiled man

I'd love to do thesis writing

Working for the private industry is some boring shit

@Slereah yeah, that's what everyone says

they change their tune at crunch time

Hell I've done it before

It was fun

more certainly more fun than having a real job

@Slereah What do you do, currrently? Not robots anymore, right?

Even that time I had to do the most boring topic

Currently I am on the dole

My most boring thesis topic is that I did a few months computing cross sections for effective models

user image

Top quality stuff

I'm not even sure if it was correct

$\pi^0 + \pi^0 \to \pi^0 + \pi^0$ being 0 seems weird

Also IIRC some don't even add up to 1

I dunno

@Slereah What process do you think should contribute to it?

9:49 PM

I mean obviously I had to cut off some terms

Maybe that's why

I would recheck but frankly I never want to see that paper again

It's during that thesis that I had to read that book entirely written in Penrose notation

AccidentalFourierTransform

@Slereah what? people really use that?

Well no

Just that one dude

some polish mathematician wrote a whole book with it

It is hellish

user image

user image

user image

AccidentalFourierTransform

I mean, even Penrose said that the notation is shitty

user image

AccidentalFourierTransform

you sure that's not something about electrical engineering?

look like circuits to me :P

9:55 PM

Nope

100% group theory

And I couldn't find another book on the topic

oh, bl$%^T&*(&(*I^dy hell

@BernardoMeurer Finally figured out why Jekyll isn't updating

it updates posts fine

it just doesn't update on changes to the config file

"£$%^&*(IO*&^%$%^&*(*&^%$%^&*(*&^%$^&*&^%$£"$%^&*(*&^%$£$%^&*(*&^%$£

Bernardo Meurer

Hahahaha

Why?

Oh

Wait

Yeah, of course it doesn't

that's on the documentation :P

I could've told you that

AccidentalFourierTransform

user image

Bernardo Meurer

@AccidentalFourierTransform +1 from Ryan

AccidentalFourierTransform

lol thanks ^.^

10:00 PM

@BernardoMeurer So here I was, uninstalling and reinstalling and fiddling with versions for the past four hours

Bernardo Meurer

Oh my god hahahaha

@Slereah lol yeah (such rigor!) worth a degree there for sure :P

Yeah the path integral thesis I did was much more fun

user image

10:18 PM

via reddit some cool cutting edge links between ML & physics

in theory salon, 1 hour ago, by vzn

Principal Component Analysis meets Renormalization Groups / Bradde, Bialek

in theory salon, 1 hour ago, by vzn

Statistical physics of inference: Thresholds and algorithms / Zdeborová, Krzakala

10:43 PM

> Sir M.V. Berry is a theoretical physicist at the University of Bristol, where he has been for nearly twice as long as he has not. (source)

^ that's... kind of... well...

obviously the universe started existing when Michael Berry was born.

11:19 PM

← universe started with me, like Shiva (+ Shakti) :P

@EmilioPisanty lol, tintin is the best

Bernardo Meurer

11:44 PM

vixra.org/pdf/1212.0137v1.pdf

Lol, apparently he solved P vs. NP AND the Riemann Hypothesis

geesh

wish i could be like that guy someday @BernardoMeurer =P

Bernardo Meurer

I wish I could be half of him!

a stepping stone for him!

Bernardo Meurer

Imagine if I ever solved P vs NP

I'd be piss drunk for the rest of my life, lol

goal: be the first woman to win the fields medal

Bernardo Meurer

11:51 PM

Piss off that'll be me!

No wait

dude, you're not a woman

@BernardoMeurer lol

Bernardo Meurer

Okay, you can have that one

@BernardoMeurer thanks for your generosity

my goal is rather unreasonable anyway =)

@heather ofc it is, because a woman already won a fields medal.

so technically your goal is impossible (to be the first) xD

Bernardo Meurer

@obe She can reveal that that woman was actually a man

and then win it

11:55 PM

that's not nice considering it's probably not true.

She just has to build a time machine and travel back to before the first woman won the medal

@obe huh, i thought i read somewhere that no woman had won the fields medal. nvm then =P

Bernardo Meurer

@obe I just wanted to prove that it isn't impossible

@heather it's recent

@ACuriousMind do i get the nobel prize in physics for that then? cuz then i get to check off two goals in one =P

@obe ah, i see.

11:56 PM

@heather Probably, yes :)

Bernardo Meurer

Is the "can you go back in time" problem solved already?

ask @Slereah

"probably not"

IIRC even a non-stably causal spacetime would fuck up

« first day (2271 days earlier) ← previous day next day → last day (2641 days later) »

Transcript for

Jan '1722

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