The h Bar

Bernardo Meurer

21:00

I avoid pinging him when he's preparing to go to the armchair

Emilio Pisanty

@BernardoMeurer surely he can spare a second to endorse the general goodness of QI

Bernardo Meurer

@BalarkaSen I don't get the meme

Balarka Sen

@BernardoMeurer It's a savage meme

you know how snoop dog plays at the background of those

Bernardo Meurer

Those what?

Sir Cumference

Isn't it snoop dogg?

Balarka Sen

21:02

whatever yes

@BernardoMeurer look up "top 20 SAVAGE moments richard dawkins" or some shit

it's everywhere

Bernardo Meurer

Lol

John Duffield

@vzn : see Wikipedia where you can read that the Biot-Savart law is also used in aerodynamic theory to calculate the velocity induced by vortex lines.

@BernardoMeurer : nope. We just got talking about permeability.

Bernardo Meurer

@JohnDuffield Are you writing a paper with @vzn?

ACuriousMind

@EmilioPisanty I'm confused as to what the show is actually about. First I thought it's a quiz show, but now they appear to be...just talking?

Emilio Pisanty

@ACuriousMind mostly, yes

Bernardo Meurer

21:06

@JohnDuffield How on earth did you make your message reference mine even though it was before mine

Emilio Pisanty

there's points given out at the end

Bernardo Meurer

@JohnDuffield IS A TIME TRAVELLER

Emilio Pisanty

which don't tend to make sense

John Duffield

@BernardoMeurer : I made a mistake.

Sir Cumference

How did obe get chat banned?

John Duffield

21:07

@vzn : Note this: "In Maxwell's 1861 paper 'On Physical Lines of Force', magnetic field strength H was directly equated with pure vorticity (spin), whereas B was a weighted vorticity that was weighted for the density of the vortex sea. Maxwell considered magnetic permeability μ to be a measure of the density of the vortex sea".

Bernardo Meurer

@SirCumference I can guarantee he was doing something stupid

That's always the cause

ACuriousMind

@SirCumference By very bluntly disregarding Be Nice. Now remember that we usually do not discuss suspensions here.

Bernardo Meurer

^ Bam

If only he was like me

I've never not been nice to someone

Balarka Sen

@ACuriousMind The suspension spectrum of the sphere has nontrivial homotopy groups

Bernardo Meurer

What's a vortex sea

Balarka Sen

21:09

You can't bar me from discussing suspensions

I will talk about reduced suspensions however much I like

ACuriousMind

@EmilioPisanty madness

Bernardo Meurer

@BalarkaSen If I was a mod I'd ban you so hard right now your account would break the time-space ripple @JohnDuffield talks about

John Duffield

@BernardoMeurer : it's something Maxwell came up with. He got it back to front.

Bernardo Meurer

@JohnDuffield Ah, nice, teach me more!

Balarka Sen

I got kicked apparently. Interesting.

nitsua60

21:11

@BalarkaSen that may have been a misunderstanding on my part.

Balarka Sen

Haha it's fine

I was making a rather obscure joke there

Suspension (topology)

In topology, the suspension SX of a topological space X is the quotient space: S X = ( X × I ) / { ( x 1 , 0 ) ∼ ( x 2 , 0 ) and ( x 1 , 1 )...

Anonymous

topology jokes don't end well

Bernardo Meurer

@nitsua60 git gud

Emilio Pisanty

@BalarkaSen "rather"?

Balarka Sen

But yeah it's offensive that people don't read nlab before being a chatroom moderator these days

That's, like, a necessary quality, man

ACuriousMind

21:14

@Blue Are you saying they're compact?

(i.e. they have no ends)

Balarka Sen

Beautiful

I love you ACM

Ends are my favorite shit

Tuki

Helo

Anonymous

lol

Anonymous

that was good

Tuki

A quick question

If you sit in centrifuge the force created by normal acceleration faces inwards or outwards ? i think this is outwards but not sure

Or whatever the device is called which is used for pilot training ?

John Duffield

21:15

@BernardoMeurer : Maxwell thought of space as something that consisted of a honeycomb of vortices through which particles passed like peppercorns through a mill.

Tuki

Device build to measure how many g:s you can take

Bernardo Meurer

@JohnDuffield Why is that needed though? Why not just not-honeycombed space

ACuriousMind

@Tuki What normal acceleration? From the viewpoint of a resting observer or of someone in the centrifuge?

Tuki

hmm does that matter ?

The force caused by normal acceleration does affect the someone who is sitting in it but doesn't affect the observer ?

ACuriousMind

@Tuki Sure, it's the difference of whether there's a centrifugal or a centripetal force

John Duffield

21:18

@BernardoMeurer : see on physical lines of force. It was his theory of molecular vortices. As to why, I can't say. The electron hadn't been discovered yet?

Tuki

So centripetal force would be facing inwards

Bernardo Meurer

@JohnDuffield But why is that meaningful nowadays since we have electrons?

Balarka Sen

@JohnDuffield Is it true that the honeycombed space is real tho?

Bernardo Meurer

@BalarkaSen Maybe for bees that's how it works

John Duffield

@BernardoMeurer : because the electron is an "optical vortex".

Tuki

21:20

So if your observer it would be centripetal force ?

Bernardo Meurer

@JohnDuffield What does that mean?

John Duffield

@BalarkaSen : no. Maxwell got it back to front.

Bernardo Meurer

Also, what does "back to front" mean

Balarka Sen

@JohnDuffield What is the front-to-back then?

Bernardo Meurer

the honeycombs are made of reality?

And not the other way around?

I agree with that

ACuriousMind

21:22

@Tuki You still haven't really told us what you meant by "normal acceleration". Can you give a bit more context?

John Duffield

@BernardoMeurer : read up on it. Start with Lord Kelvin, 1867. And remember that the electron hadn't been discovered yet.

@BernardoMeurer : the particles are the vortices.

Balarka Sen

can you introduce me to the idea?

i have trouble in reading comprehension

how can a particle be a vortex

John Duffield

@BalarkaSen : See the heady collisions Columbia article which likens particles to tornadoes and hurricanes.

Tuki

If you were to swing a rope this force would keep the end of the rope on it's trajectory which is circle in this case. Lets say you were swinging it on $x,y$ plane where gravity is facing $-y$ in this context the force that would keep it from falling off this trajectory @ACuriousMind

ACuriousMind

@Tuki Ah yes, that is indeed the centripetal force pointing inward.

Tuki

21:25

But i thin this issue really boils down to that i don't have good understanding on the difference here

between these two forces

Centripetal and centrifugial

Bernardo Meurer

@JohnDuffield I guess my question is, if we have electrons nowadays, why are these theories that predate it and use vortices and stuff matter?

John Duffield

@BernardoMeurer : because the Standard Model is incomplete.

vzn

@JohnDuffield lol reminds me of cellular automata o_O

Bernardo Meurer

@JohnDuffield How do we know that?

John Duffield

@vzn : it doesn't remind me of cellular automata.

vzn

21:28

@BernardoMeurer good question. the short answer is not every physical theory we have is complete/ finished.

Bernardo Meurer

I mean, why not just say "This is it folks, these are all the particles"

John Duffield

@BernardoMeurer : you perhaps don't, but I do.

vzn

@JohnDuffield he was literally talking about cells in some other quote iirc.

Bernardo Meurer

@JohnDuffield Wat? So we know the Standard Model is incomplete because you know it?

Tuki

Another thing thing is that centripetal and centrifugal forces are equal but are facing the opposite direction right ?

centripetal + centrifugal = 0 ?

Bernardo Meurer

21:29

That doesn't sound like the most canonical of proofs

bolbteppa

@JohnDuffield Why do you think string theory is the only way to unite quantum mechanics with general relativity properly?

Lozansky

@Tuki Yes of course

John Duffield

@BernardoMeurer : if you think it's complete, describe the electron to me.

Tuki

ok ok good

Lozansky

It is a ficticious force due to a non-inertial reference frame

ACuriousMind

21:30

@Tuki That's...not a good way to think about them. You cannot add them because there's no frame in which there is both a centrifugal and a centripetal force.

John Duffield

@bolbteppa : I don't think that. I'm not a fan of string theory.

Bernardo Meurer

@JohnDuffield Whether or not it's complete I wouldn't be able to describe the electron to you

It's a tiny ball that shocks things

John Duffield

@BernardoMeurer : then tell me why it has the mass that it has.

Bernardo Meurer

@JohnDuffield Because we weighted and that's the mass it has?

Something something Higgs field?

vzn

@JohnDuffield found it it was in a direct ref you recently cited on wikipedia en.wikipedia.org/wiki/…

bolbteppa

21:31

@JohnDuffield why do you think nearly every professional who understands string theory claims that it unites quantum mechanics with general relativity, and says it's the only game in town?

John Duffield

@BernardoMeurer : no. It has the mass that it has because Planck's constant is what it is.

Balarka Sen

@JohnDuffield I don't understand why that article describes particles as vortices

vzn

> I conceived the rotating matter to be the substance of certain cells, divided from each other by cell-walls composed of particles which are very small compared with the cells, and that it is by the motions of these particles, and their tangential action on the substance in the cells, that the rotation is communicated from one cell to another.

Anonymous

It's going to be good entertainment to just sit and watch this conversation :D

Bernardo Meurer

@bolbteppa Because otherwise they'd be jobless

Tuki

21:32

Now according to wikipedia the centrifugal force would be considered as "pseudo" force but my intuition would tell me this is clearly the other way around ?

Balarka Sen

I just see an interaction where some of the resultant particles spin around after the collision

John Duffield

@BalarkaSen : go and read up on "spinors".

bolbteppa

haha

Balarka Sen

you already made me read too long a thing! please explain senpai

i have trouble reading long things

Bernardo Meurer

@JohnDuffield But wait, Planck's constant isn't like a real thing, right?

How can that be why they have mass

ACuriousMind

21:33

@BernardoMeurer Fermion mass is actually a "side product" of the Higgs mechanism, and if it only was the process for setting Fermion masses it wouldn't be much of an explanation since you just shift the necessary input from the mass parameter to the Higgs VEV parameter. Higgs is really needed for the W and Z masses.

John Duffield

@BernardoMeurer : of course it's a real thing. It's common to all photons. E=hf and all that.

Bernardo Meurer

@ACuriousMind Then what's the real mechanism?

John Duffield

@BernardoMeurer : because you make electrons and positrons out of photons in gamma-gamma pair production. PS: can you tell me how pair production works?

Bernardo Meurer

@JohnDuffield Nope, can you?

John Duffield

@BernardoMeurer : yep.

Bernardo Meurer

21:34

How?

ACuriousMind

@BernardoMeurer Hm? I don't understand the question. (If you're not serious please stop here :P)

Balarka Sen

@JohnDuffield you didn't explain to me what a spinor is and how their existence implies that article says particles are vortices

Anonymous

@ACuriousMind You really thought BM was being serious all this while?

Balarka Sen

teach me pls

Anonymous

:P

Balarka Sen

21:35

i like physics and i want to learn

Anonymous

Balarka too

John Duffield

@BernardoMeurer : it would take me too long. I'd have to explain the photon, then the electron, then bridge the gap.

ACuriousMind

@Blue Not all this while, but I thought he might actually want to learn something about the Higgs mechanism if I offered.

Balarka Sen

@ACuriousMind you have fallen into the trapp

use diffeomorphism to escape

Anonymous

@BalarkaSen Yeah, and you'll find the formula in an Einstein paper

ACuriousMind

21:39

Okay people, can we go back to the state where we can trust each other that most of what is said here is actually a somewhat serious attempt at conversation? Also remember how this looks to passing-by on-lookers.

Bernardo Meurer

@ACuriousMind gist.github.com/556dfef3dc47ca36390c0b16417fc178

@JohnDuffield Okay, can you just explain me the photon then?

Or the bridge gap

One of the two

vzn

← thinking very hard, Whats The Real Mechanism™ o_O

John Duffield

@BalarkaSen : I can't do everything. You have to do your own research.

Balarka Sen

John Duffield

en.wikipedia.org/w/index.php?title=Spinor

Balarka Sen

21:41

@JohnDuffield but i want to learn

i dont want to do research

John Duffield

en.wikipedia.org/w/index.php?title=Spinor&oldid=831315251

Bernardo Meurer

What I want to know is where do the ripples come into this

John Duffield

See this: "Spinors were introduced in geometry by Élie Cartan in 1913.[1][2] In the 1920s physicists discovered that spinors are essential to describe the intrinsic angular momentum, or "spin", of the electron and other subatomic particles".

bolbteppa

"In mathematical terms, spinors are described by a double-valued projective representation of the rotation group SO(3)" I wonder what this means

ACuriousMind

@BernardoMeurer Oh, shoot, I don't have the private key for that anymore.

Bernardo Meurer

21:43

@ACuriousMind O.o

You lost your pkey?

ACuriousMind

It was on the Windows installation that died :P

Bernardo Meurer

SO?!

YOU DIDN'T BACK UP

OR HAVE A REVOKE KEY?!!

I TRUSTED THAT KEY

ACuriousMind

I use PGP about once a year :P

It was very low on my priority list

Bernardo Meurer

Now we can't communicate securely

Look what you've done

vzn

@BernardoMeurer lol rhymes with nipples :P

Balarka Sen

21:44

Minecraft - Damage Sound

►

Bernardo Meurer

and even worse

I can't trust you're not an impostor

John Duffield

@bolbteppa : See eometric Model for Fundamental Particles by Batty-Pratt and Racey, 1980.

Bernardo Meurer

So I can't ask you to just "make a new one"

You've ruined my secure comms

Balarka Sen

tfw ACM is a malware

ACuriousMind

Well, technically, you shouldn't have trusted that key in the first place because you hadn't verified who I am, right?

Bernardo Meurer

21:46

@vzn Is that how photons work? Nipples?

vzn

@BernardoMeurer am trying to put it in terms you might understand :P

Bernardo Meurer

@ACuriousMind I did, I had access to your webcam when I trusted it

@vzn I have never seen a woman's nipple, I'm saving my eyes for marriage

So thank you, but I will avoid your vulgarity in Physics

Balarka Sen

But you have seen your own

vzn

@BernardoMeurer that reminds me just saw 50shades last sun. not bad for a (S&M) soap opera :P crying its the last in the series :'( ps with 2 latin ladies =D

Bernardo Meurer

@BalarkaSen Allegedly

Balarka Sen

21:47

@BernardoMeurer Are you telling me you have none?

Dam son

Bernardo Meurer

@vzn If you want porn just watch porn

I don't get it

Why watch a movie with fake-porn, when you can go online and get real-porn

vzn

@BernardoMeurer lol its like porn for women :P

Bernardo Meurer

@vzn But you loved it

Balarka Sen

Fifty Shades of May

►

I watch this everyday

no_choice99

anybody knows the QM book by ballentine? coz I've found a note claiming that the chapter on spherical tensors is wrong in many plances (so no typos... just wrong, senseless). can somebody tell me whether it's serious? famaf.unc.edu.ar/~raggio/QM2/bzt.pdf

Bernardo Meurer

21:49

@vzn There's a reason I date a girl who doesn't speak neither English nor Portuguese

Makes communication a lot easier

We talk in first-order logic

vzn

@BernardoMeurer you are monogamously dating? now thats news! what does she speak?

bolbteppa

@JohnDuffield the first page talks about simply connected Lie groups as being the only allowable motions, but the Lorentz group is not even connected let alone simply connected, hmm

John Duffield

@BernardoMeurer : a photon has an E=hf wave nature. It's moving linearly through space at c. An electron has a wave nature, but it has a "spinor" nature too. It isn't moving linearly through space at c. Now why do you think that might be?

Bernardo Meurer

@vzn The day I'm monogamous you can send me to the psych ward

ACuriousMind

@vzn Take your sexism elsewhere.

Bernardo Meurer

21:51

@ACuriousMind Well, according to my thesis he's not wrong, it's just not specific to women

:P

@JohnDuffield hf?

Because the electron is fat?

i.e. has more mass

Balarka Sen

@ACuriousMind You might be the only one who'd enjoy the video I posted

Bernardo Meurer

Did @vzn get banned?

John Duffield

@BernardoMeurer : no, and I'm afraid I have to go. Sorry. But I will be putting all this up on the internet at some point.

Bye.

ACuriousMind

@BernardoMeurer Only kicked for a minute.

@BalarkaSen Heh.

Bernardo Meurer

@JohnDuffield Bye, make a blog!

@ACuriousMind That seems a bit much just for stating the NP-Hardness of human comprehension

no_choice99

21:56

@EmilioPisanty do the claim of ballentine writting non sense about spherical tensor looks serious at first glance?

Bernardo Meurer

@no_choice99 Everyone in physics is writing nonsense

Balarka Sen

I'll have to stop shitposting and go to sleep now

See you all on the flip side

Emilio Pisanty

22:14

@no_choice99 no idea, I don't know that book.

nitsua60

@BernardoMeurer If they were, anyone who knew really shouldn't be talking about it, no?

David Z

^^

Bernardo Meurer

@nitsua60 No, you're wrong. Mods have always disclosed banning, it's actually not their choice since you can see it on the user's profile, they don't discuss reasons, which I didn't ask about

nitsua60

In which case, you can go look. So what's the question?

David Z

Although our "official" rule is that mods won't talk about it, while non-mods are merely discouraged (but not forbidden) from talking about it.

Bernardo Meurer

22:17

@nitsua60 The question was whether he got banned or not, and hey, it got answered!

Amazing :)

vzn

!?! geez dedicated to ACM & the hair )( trigger bye for now blogs.scientificamerican.com/the-curious-wavefunction/…

Bernardo Meurer

@vzn Had you read my essay he wouldn't have kicked you

nitsua60

@vzn Do you have time (a few minutes) for a serious question?

David Z

@nitsua60 BTW we have a backup room you're welcome to use if you like, no obligation though

Bernardo Meurer

@nitsua60 You will regret asking your question, whatever it might be, trust me on this

Sir Cumference

22:33

:43522319 Why was my message removed

Come on, let me talk freely

dmckee

23:10

@BernardoMeurer Not everybody does. My better half loves it. I figure that between 5 and 10 percent of engineering and physics students really like it.

Mind you, I'm not one of them.

I find the classical theory to be handicapped by the opacity of it's historical development (which must be considered a vast triumph, BTW).

I find the foundation of the statistical theory to be one of the most elegant things going, but actually working problems quickly bogs you down in a mire of partial derivative identities.

And I can work with those but I don't like it.

nitsua60

@BernardoMeurer For the record, I did not regret asking. (cc: @vzn)

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