The h Bar

4:00 AM

@0celo7 will i be safe in tennessee as a fully automated luxury radical feminist communist

i regret bringing anime into this. i just brought it up as an example because it's more relatable and easy to understand than other examples and it's instead of some cliche 1984 example everyone uses.

G. Bergeron

@eulB but see we're both positing statistics to be nearer to what we want it to be. As my position is mostly ideological in nature, I don't see the point of going out to dredge papers so that we can throw statistics around each other...

0celo7

@EricSilva we haven't had a commie lynching in 15 years

G. Bergeron

@eulB Your analogy served its prupose for me

Eric Silva

very reassuring

eulB

4:02 AM

@G.Bergeron well it's not what i want actually it's just for something like crime you'd have to take the worst case scenario because the criminal is already in the wrong and doesn't deserve benefit of the doubt.

i don't really like having beliefs so i just change them up from time to time and play devils advocate a lot.

G. Bergeron

@eulB I disagree on that

0celo7

I think @eulB is trolling

eulB

a little bit

G. Bergeron

am I the only one not trolling?

eulB

ironically

skullpatrol

4:03 AM

yup

Eric Silva

idt i was trolling?

G. Bergeron

now I feel stupid

@skullpatrol -_-

0celo7

Some say my personality is a troll, and no one knows who I really am

eulB

wait no i was only trolling like 30%.

0celo7

I don't know this is true, I might be trolling myself

eulB

4:04 AM

I think you hold your beliefs too dear @G.Bergeron

skullpatrol

Trollers gotta troll

eulB

because you're the one arguing against what everyone else thinks.

and don't want to change your mind.

G. Bergeron

@eulB I just think we do not operate under the same moral premises

Eric Silva

@eulB idk if this is a good reason tho

eulB

it's not

Eric Silva

4:05 AM

i think there's a good reason to be self critical but that isnt it

G. Bergeron

@eulB Oh so being a minority on those kind of topics is cause for being wrong, ok...

eulB

the debate is finished isn't it? this isn't refuting him or invalidating what he said before.

i'm just saying it.

G. Bergeron

yeah we went to the meta-debate

Eric Silva

idk what was being debated

eulB

@G.Bergeron it's not but if you're going to go against what is standard you better have some solid data or evidence to back it up.

skullpatrol

4:06 AM

Master debater.

eulB

otherwise you could be deluded.

not saying you are.

0celo7

@JohnRennie feel free to delete the last two hours of the chat

G. Bergeron

@eulB I disagree as this is a debate of ideologies, at the end of the day

eulB

oh

G. Bergeron

@0celo7 yep

0celo7

4:07 AM

@G.Bergeron for the record i was not trolling

eulB

having ideologies is dumb i always say. people should constantly be changing their worldview based on newfound evidence and objective truths.

otherwise you'll get dumb arguments all the time. with no real way to determine who is right.

G. Bergeron

My call on being trolled was for comic relief, if we need to be explicit

eulB

and people will want to defend their beliefs.

G. Bergeron

@eulB Not if you reject the notion of objective moral...

eulB

some things can be made objective.

G. Bergeron

4:09 AM

If we where discussing physics, then I agree completely

Eric Silva

idt the initial debate was really one of ideology

being critical of the carceral system doesnt have to be anyway

G. Bergeron

@EricSilva Not initially, but then we shifted

Eric Silva

it morphed into weird ethical posturing that i dont understand

0celo7

I dunno

eulB

in fact i'm pretty sure given enough information about everything in the universe and a good enough computer that can simulate it using physics we already know, you can form lots of objective truths including moral ones as some kind of optimization problem.

^does anyone disagree with that and why

0celo7

4:10 AM

@EricSilva how far are you in wald

G. Bergeron

@eulB What you said is an oxymoron to my ears

Eric Silva

im at chapter 4

eulB

which part?

G. Bergeron

See? We are having an ideological debate

0celo7

chapter 4 is where the book starts

so, good

Eric Silva

4:10 AM

@eulB i wont disagree w it if u can show me it

eulB

yeah but i don't care about my ideology

Eric Silva

otherwise im gonna be skeptical

eulB

yeah

im saying

is it reasonable in theory?

not in reality

G. Bergeron

@eulB positing moral truths to be objective IS an ideology, so yes you are

eulB

@G.Bergeron i'm saying it can be made that way with enough information

if you optimize for things.

G. Bergeron

4:12 AM

@eulB And I'm saying it can't

Eric Silva

idk if i have a compelling reason to believe you could simulate a person let alone society

so idk

G. Bergeron

Yeah well the choice of the ''cost function'' for your optimization will encode your choice of moral ''axioms''

eulB

@EricSilva you can make simplifications.

@G.Bergeron yeah

G. Bergeron

@EricSilva I take it for granted you can

0celo7

@EricSilva important for the summer school will probably be 9-12

Eric Silva

4:13 AM

@eulB idk if a simplified simulation would be good enough

G. Bergeron

@eulB but as you can't prove these axioms... ideologies

eulB

@EricSilva yes it could because you could simplify the decision making process by some decision making algorithms that mimic humans

Eric Silva

i think it's easy to believe that a little bit more complexity makes things fundamentally different

eulB

you don't need to simulate the full brain

Eric Silva

you're just claiming that though

i dont have a good reason to believe it

eulB

4:14 AM

but why couldn't you?

this is all in theory

Eric Silva

what if any reduction in complexity makes it so simplified as to be completely different? new phenomena might emerge that makes it so fundamentally different that it cant be a good model

@0celo7 hopefully i can get there in time

G. Bergeron

@skullpatrol Are you calmly asking us to bring this elsewhere? It might be wise to do.

Eric Silva

with classes on top of my MCF project idk how much time ill be able to devote to GR

skullpatrol

yup

0celo7

@EricSilva 10 especially

skullpatrol

4:16 AM

I tried two hours ago :-)

eulB

@EricSilva because you have data too.

Eric Silva

@0celo7 i will do my best to get there at least

eulB

@EricSilva if you have enough data on humans now, and you can find an artificial way to mimic it that matches the data over a big enough interval then it should be fine.

G. Bergeron

@skullpatrol I was only here for 1 hour

eulB

and since this is in theory and i'm not saying it's definitely true practically i don't see how you can disagree.

0celo7

4:17 AM

@EricSilva I tried to read 10 in high school and decided I could never be an analyst

Eric Silva

@eulB like im fine with you taking this position as a thought experiment, idc, but i dont think it's well justified

0celo7

how the times have changed ::sniff::

Eric Silva

@eulB if you cant say how you would do it in theory i have no reason to believe that it's a good assumption to make that you could

G. Bergeron

@eulB I'd wager on the contrary, actually. It's a completely chaotic dynamic

Eric Silva

@0celo7 lol y would u try to read this in hs of all times

G. Bergeron

4:19 AM

The required precision for a useful simulation grows exponentially with time.

@skullpatrol Well ok...

0celo7

@EricSilva why did Balarka read Hatcher in middle school? Boredom

eulB

@G.Bergeron i said before with enough computing power, and also it doesn't have to be over an interval big enough for the chaos to factor in that much.

G. Bergeron

Time flies by, apparently

Eric Silva

@0celo7 he's a special lad

skullpatrol

:-)

0celo7

4:20 AM

@EricSilva im special too !

eulB

im special three

Eric Silva

well i guess im not so special

G. Bergeron

@skullpatrol At least it seems we where not drowning another thread

Eric Silva

but i think that's ok

0celo7

sadface

skullpatrol

4:20 AM

True

Eric Silva

@0celo7 my foray into math was reading rudin in hs

that was the end of that

i would be an analyst forevermore

eulB

i am so special that they put me in a separate class reserved for only the special kids.

0celo7

I tried reading Rudin in high school

I couldn't get past the first page with the exponential as a power series

G. Bergeron

wow, so I came to my computer 2 hours ago wanting to work on some neural nets and instead just spew out words on here!

0celo7

@G.Bergeron I had fully intended to do a calculation

I blame you for this

G. Bergeron

4:22 AM

@0celo7 yeah well, you know, all that stuff about the blackhole of productivity...

2

Eric Silva

i did a little work but not much

G. Bergeron

@0celo7 and I co-blame you for this!

0celo7

don't you pull that algebra crap here

G. Bergeron

@0celo7 Aren't you in math?

0celo7

I did determine that the $D_\sigma$ in this paper is an annulus, not a disk

confusing symbol choice

@G.Bergeron yes

G. Bergeron

4:24 AM

Oh I see, an analyst

yeah I spend my days in co-everything

0celo7

I hate algebra so much I drink ffee, not coffee :P

skullpatrol

@0celo7 what age?

Cows

Is anyone here a Java expert?

G. Bergeron

:D

0celo7

@skullpatrol 16-17?

Eric Silva

4:25 AM

algebra is p good @0celo7

0celo7

I'm kidding

eulB

@G.Bergeron i said yeah to this by accident because i misread. i don't agree because you can use the laws of physics as your axioms that you'll optimize off of like entropy for example. but let's not continue, and yes i do accept that there's probably lots wrong with that too.

0celo7

Although it's really disjoint from my main interests

Cows

Is there any Java expert here ? I need to talk about some Java stuff

Eric Silva

i thought of being an algebraic geometer once

eulB

4:26 AM

did you check stackoverflow?

Cows

hmm let me check

G. Bergeron

@Cows I wrote like 3 lines of Java in my life

0celo7

@EricSilva 1. geometric analysis 2. evolution equations 3. harmonic analysis

Cows

@G Bergeron well I am interested in getting some hardcore java concepts clarified likec covariance and contravariance and invariance. And then some gradle stuff and dependency injection stuff

G. Bergeron

Now there is this nice bottle of scotch looking at me and work waiting to be done...

Cows

4:28 AM

@G.Bergeron then once we do that, I want to code some stuff live and get some feedback

0celo7

@EricSilva and the genius thing about 1. is that it uses 2. and 3.

G. Bergeron

@Cows When I hear covariance and contravariance I think of tensors or morphisms.

eulB

i took a java class in high school and didn't write a single line of java and still passed somehow. it was ap compsci btw.

i still don't know how that even worked looking back.

Eric Silva

@0celo7 i think im probably gonna try to do geometric analysis, it's like 99% gonna be something broadly differential geometric

but still maybe pure analysis of PDE, idk

Cows

@G.Bergeron yeah does concepts are in CS even observables and so forth are bleeding edge cs stuff

0celo7

4:30 AM

@EricSilva the geometry isn't as interesting to me as the PDEs/analysis you need to solve the problems

G. Bergeron

@Cows And dependency injection seems like something you never want to do :p

0celo7

which is why I might end up doing Klainerman-type stuff

Cows

@G.Bergeron except in CS (Java/scala) etc they mean some weird things

Eric Silva

i like the geometry more i think

Cows

@G.Bergeron hehe

Eric Silva

4:31 AM

my interest began w do carmo so i was deeply influenced by that classical diff geo stuff

0celo7

my interest began with Zee's GR book

G. Bergeron

@Cows yes, yes I've seen some formalization of these variance things in CS, but that might not be the same as what it means in a specific language

0celo7

not the Zee from the math chat, obviously

eulB

my interest began when i tried to pour my coffee in my donut instead of my mug because i was told they're the same thing. i'm dedicating my life's work in mathematics to figure out why it didn't work.

G. Bergeron

@0celo7 Ha, and to me it's the algebraic part that is the most interesting part :P

0celo7

4:32 AM

@eulB because the natural category is the Riemannian category, not the homotopy category

Cows

@G.Bergeron yes. the cs guys have managed to make money from super abstract math concepts and justifiably so

eulB

@0celo7 shhh spoilers

G. Bergeron

@eulB That might be the start of a good practical joke on all the topologist in the department: '' So a doughnut is the same as a mug, huh?''

0celo7

@G.Bergeron the algebraic part of geometric analysis? it's basically empty :P

G. Bergeron

@0celo7 of geometry

Cows

4:33 AM

@G.Bergeron in fact Haskell guys have taken this to the next level. hehe

G. Bergeron

@Cows It's what I'm trying to do now, in a sense

Eric Silva

@0celo7 i do love the analysis though, dont get me wrong, i think my motivations tend to be rooted in geometry still but sometimes the analytic motivations trump the geometric ones

eulB

@G.Bergeron that'll get old really fast and will sacrifice lots of donuts every time you tell it to a topologist in the coffee lounge.

the janitor will hate you too.

0celo7

@EricSilva I think that manifolds are a lot more interesting than R^n

eulB

let's hope he wasn't a hired killer in the past. xd

0celo7

4:34 AM

and geometric problems make a lot more sense to me than pure analysis ones

Eric Silva

i mean yes agreed

skullpatrol

@0celo7 he's your new favourite :P

G. Bergeron

@eulB I was thinking along line of replacing their cups

Cows

@G.Bergeron oh nice

0celo7

@skullpatrol I think that Zee is a fine troll. Back in the day we would have caused havok

eulB

4:35 AM

@G.Bergeron with donuts? lol that could work too but they might not get it unless you make a punchline.

i was thinking of asking them if they want coffee and then pouring it for them on a donut .

G. Bergeron

@eulB If you do it to an entire office, I don't see how they will not

@eulB That might be better and entirely worth the cost of the doughnut

eulB

how do you gather all the topologists in the department in one office with a coffee maker?

0celo7

well, the earth is a disk, so just do a radial contraction

eulB

they should add that to the list of millennium problems.

G. Bergeron

@eulB you continuously make coffee?

Eric Silva

4:37 AM

@0celo7 i think an example of what i mean about analytic motivations taking precedent sometimes is like, simons equation for the second fundie

0celo7

what about it

Eric Silva

i think it's waaaay easier to see why it's important analytically than geometrically, i have no idea what it's saying geometrically really

0celo7

@EricSilva oh

eulB

looking back at every joke i made in the last 30 mins i just made myself cringe a few times. i guess that means i should go to sleep.

gnight dudes

G. Bergeron

@eulB see you

0celo7

4:38 AM

@EricSilva Ah, this problem is what my summer project is about

Eric Silva

that's interesting

0celo7

there's something for minimal surfaces that should be true for black hole horizons

Eric Silva

i tried to think about it when i was taking my colding minicozzi class with André but i thought that equation was very elusive

0celo7

it's kind of clear how to generalize it analytically, but geometrically it is not so clear

and in the minimal surface case, it's crucial to understand both points of view

Eric Silva

if u make progress explain me a thing

0celo7

4:40 AM

my prof has a paper on it in jdg, I'll send it to you when they finally get it published

Eric Silva

cool

0celo7

should be any day now

Eric Silva

my interest in understanding the geometrical meaning is very $\geq M$ where $M$ is a big

0celo7

this is related to stability

and some stuff of Brian White with regularity of stable minimal surfaces

it's much harder to do this for black holes, but some people think there are analogous results

so like for stability of minimal surfaces you have the CoV viewpoint or the eigenvalue viewpoint

the stability of black holes is harder to describe

Eric Silva

idek what a black hole is

0celo7

4:43 AM

Chapter 12 of Wald

Eric Silva

very far from there still :(

skullpatrol

it's where God divides by 0

G. Bergeron

I need a better book on GR

0celo7

@G.Bergeron they come in all shapes and sizes

none of them use algebra

so, all nonalgebraic shapes and sizes

Eric Silva

@0celo7 i have the motivation to read wald now so im gonna leave this place and do that

fare well

0celo7

4:44 AM

cheerio

good luck

G. Bergeron

I know

skullpatrol

cya pal

G. Bergeron

I found this Misner, Thorne and Wheeler in a box somewhere

0celo7

MTW is pretty rough

I should get it but I already have a ludicrous number of books

G. Bergeron

When you know a fair bit of diff geo its mostly lengthy in the beginning

skullpatrol

4:46 AM

Wheeler came up with the word "blackhole"

0celo7

it's lengthy in general

I don't think it goes into enough detail either

someone should write a GR book for mathematicans that's not so hard to read as Sachs and Wu

G. Bergeron

I haven't work through it really

0celo7

problem is Wald is so good, it'd be hard to write a book that doesn't copy large parts from him

G. Bergeron

I courses in GR before, so my motivation is not as high as it could be

s. patroller

6:02 AM

in English Language & Usage, 11 hours ago, by Mitch

agaitaarino

In the (undercrowded) Quantum Computing SE beta site someone asked about Explicit Lieb-Robinson Velocity Bounds (quantumcomputing.stackexchange.com/questions/1620/… ). I found the question worthy and offered my first bounty on it... which is still unclaimed. Maybe some people from the h bar are up for that?

3

Balarka Sen

7:17 AM

@0celo7 jeesus

Slereah

8:35 AM

mornin

John Rennie

8:48 AM

quiet in here ...

Slereah

well it is sunday

everyone is at church

Dawood ibn Kareem

Why did someone post a map for an Easter hunt? It's a couple of weeks too late.

Slereah

maybe they didn't find all the eggs

Dawood ibn Kareem

They might have been frightened off by the snakes or the crocodiles.

Slereah

9:06 AM

I wonder how snake eggs taste

Dawood ibn Kareem

Probably much like chicken eggs. I don't know why they wouldn't.

Slereah

because they are not chickens

Dawood ibn Kareem

quora.com/What-do-snakes-eggs-taste-like

Apparently, they taste like eggs. Who knew?

And the respondent is French, so he must be right.

Slereah

Dawood ibn Kareem

If I was a snake, that would really ****** me off.

I seem to have inadvertently trained one of my pigeons to perch on the back of my neck and nibble on my ear.

Cooking and Eating PYTHON EGGS!

►

agaitaarino

9:19 AM

Sorry for the ugly link above. I'll repeatthe question to make it look as it should:
In the (undercrowded) Quantum Computing SE beta site someone asked about Explicit Lieb-Robinson Velocity Bounds. I found the question worthy and offered my first bounty on it... which is still unclaimed. Maybe some people from the h bar are up for that?

12

Q: Explicit Lieb-Robinson Velocity Bounds

Lieb-Robinson bounds describe how effects are propagated through a system due to a local Hamiltonian. They are often described in the form $$ \left|[A,B(t)]\right|\leq Ce^{vt-l}, $$ where $A$ and $B$ are operators that are separated by a distance $l$ on a lattice where the Hamiltonian has, for ex...

John Rennie

@agaitaarino The problem is that all the QC fans on this site are already participating in getting the QC site going. So there's unlikely to be anyone here who knows the answer but hasn't already seen your question on the QC site.

Sadly what I know about QC could be written on a flea's backside ... in a large font :-)

agaitaarino

It sure doesn't feel like all the QC fans/experts are already participating over there (there's a lot of loneliness), but it may well be that that is in fact the case. Thanks anyway!

David Richerby

9:42 AM

Bad news, everyone. Physics is broken.

I just dropped an open packet of butter off my kitchen counter and it landed butter-side up.

ACuriousMind

@G.Bergeron They don't, necessarily. For instance, in the Palatini formalism, the metric and Christoffels are a priori independent dynamical fields, and the usual relation between them is an equation of motion.

@DavidRicherby It has been for a while. We try not to draw attention to it.

David Richerby

OK. The secret's safe with me.

Actually, I'm glad it's not a new result. It would be embarrassing for an outsider to discover something so important.

Mithrandir24601

10:08 AM

@agaitaarino Have you tried maths or CS (or math overflow or CS theory)?

I have to admit, I've never even heard of Lieb-Robinson Velocity Bounds

David Richerby

My impression is that QC was started in part because CS isn't very good at anwering quantum questions. I'd stlil recommend that you advertise your question in CS chat but I'm not sure it'll achieve much. :-( (Please don't cross-post the question itself.)

agaitaarino

10:27 AM

@Mithrandir24601 I did try math overflow (they have a special chat for bounties there), and CS theory, as well as CS general.

Mithrandir24601

@agaitaarino Well, hopefully someone will have something then

Slereah

10:49 AM

HILARIOUS Husky Sneeze

►

important

agaitaarino

11:25 AM

In related news, I have myself an unanswered question on decoherence, vs "disentanglement". No bounty yet, but totally willing to put one if that will help.

2

Q: Decoherence of spin-entangled triplet-pair states in the solid state: local vs delocalized vibrations

The context: We are in the solid state. After a photon absortion by a system with a singlet ground state, the system undergoes the spin-conserving fission of one spin singlet exciton into two spin triplet excitons (for context, see The entangled triplet pair state in acene and heteroacene materia...

architecture quantum-entanglement quantum-decoherence

Secret

12:33 PM

[Random]

"Completely indeterministic spacetime" A spacetime where every event along any worldline is unprecedented

that is worse than passing through a cauchy horizon. Not only the future cannot be predicted, but that every future instant is a event never seen before

Captain Bohemian

12:52 PM

I made a dream in which I was making dissertation.

Slereah

sounds more like a nightmare

Captain Bohemian

my mood inside the dream was anxious.

when I just waked from my dreamland, I could still slightly remember the contents I presented, but just several minutes later, I have forgot all of them.

Secret

is it GR based?

Captain Bohemian

I forget. Something regarding spacetime.

Though I used to follow a professor in GR for my MSc, his project I was affiliated was always called geometrodynamics rather than GR such and such.

Secret

1:08 PM

sounds like LQG stuff

John Rennie

@knzhou I appreciate you trying to reason with John Duffield, but honestly you are wasting your time. He does not understand GR well enough to understand your argument and he will just keep repeating his personal views regardless of anything you say.

ACuriousMind

@JohnRennie I think knzhou knows full well who they're arguing with, cf. this comment from the last election:

> Be careful, it's a false dichotomy. Duffield is trying to convince you that either he's wrong, or ACM can be overly picky about what's right. But actually, both are true! – knzhou Sep 30 '16 at 2:58

Note that leaving a comment pointing out why an answer is wrong has value even if you're not going to convince the author with it.

Slereah

@ACuriousMind What's the Hilbert space equivalent of $0$-dimensional QFT using path integral

Abcd

@JohnRennie now?

ACuriousMind

@Slereah I'm afraid I don't understand the question

Slereah

1:18 PM

Is it the trivial $1$-dimensional Hilbert space?

@ACuriousMind For pedagogical reasons people sometimes use a QFT in 0 spacetime dimensions

but it's always using the path integral formalism

Is there a canonical version of this

ACuriousMind

@Slereah The trivial Hilbert space is clearly the zero-dimensional vector space :P

Slereah

@ACuriousMind You know what I mean :p

$\mathbb C$

ACuriousMind

@Slereah Since I've never seen that, I can't really say what they mean

Slereah

@ACuriousMind here's an example

dec41.user.srcf.net/h/III_L/advanced_quantum_field_theory/1

Basically in 0 dimensions the path integral measure is just the Lebesgue measure

hence things become very simple

ACuriousMind

Ah

There is no Hilbert space, this is not a quantum theory :P

Slereah

1:22 PM

Too bad!

Not even one with a single state?

ACuriousMind

I mean, this is not even a proper physical theory in the usual sense: There is no actual action, since the action by definition would be an integral over time, but there is no time

They're just doing "QFT in 0 dimensions" to get the results for the path integrals they can then generalize to higher dimensions where they can't actually derive these results :P

Slereah

Well if you add one time dimension, you just end up with non-relativistic QM :p

Still simple, but not as nice!

ACuriousMind

I would claim that "QFT in 0 dimensions" is so simple precisely because it has no actual physical content :P

Slereah

You can still perform a measure!

Only one, but still!

Captain Bohemian

is the measure referred often in quantum gravity just something like volume form or the degeneracy of a quantum state? I often see the term "measure" in the papers regarding quantum gravity, but don't quite know what it is.

Slereah

1:25 PM

@CaptainBohemian depends on the context, I guess?

Captain Bohemian

@Slereah really? there are more than one meaning of "measure" in the context of quantum gravity? Recently, I also found in math department there is also the subject measure theory. I wonder if the "measure" in "measure theory" means the same as the "measure" in quantum gravity.

Slereah

Quantum gravity has a bunch of measures

Could be the usual spacetime measure form

The Haar measure in LQG

One of those fancy path integral measure in Euclidian gravity

Captain Bohemian

@Slereah I seem to have ever seen the term " Haar measure" or "Haar xxx (something I can't recall)" in my book regarding geometrical physics. Let me check the book what it is again.

Emilio Pisanty

1:44 PM

0

Q: Plot graph between coulomb force F versus 1/r^2

Plot a graph between F versus 1/r^2....for both pairs of charges Electrostatics is concerned with the electrical fields and scalar potentials of stationary electrical charges and charge distributions. Use this for questions about electromagnetic situations in which currents and magnetic fields ar...

electrostatics

wha...?

Swapnil Das

2:23 PM

@Slereah Have you studied Loop Quantum Gravity

?

Slereah

Not really

I have Rovelli's book, but it's a bit much for me

Transcript for