The h Bar

Slereah

12:02 AM

From what I can see the generators do seem to belong to the Cauchy horizon?

Maybe?

I dunno

HE doesn't seem to talk about it

Let's check Wald

Ah yes, Wald seems to be it

The generator's tangent vectors are within the surface

In which case it's pretty normal for Misner space to be compactly generated

And I think Kerr isn't because it doesn't even have a Cauchy horizon, I think

Oh wait, it does

Hm

"The Cauchy horizon is composed of null geodesic generators which can have no past endpoints [4]. If this horizon is to arise from a compact region, each generator must wind around indefinitely inside this region as one goes into the past. This in turn requires the generators to originate as a closed null geodesic called the fountain."

Pretty sure that the answer is in this

I must focus myself on it

Stare at it intently

>8|

Slereah

12:36 AM

Ah, finally found a good paper on the topic

0celo7

1:08 AM

nice rant there

Slereah

Well nobody was helping :V

But apparently in compactly generated spacetimes, there's a "fountain"

The Cauchy horizon starts out as a little closed null curve

And then null geodesics radiate out of there

Compactly constructed just means that in the closure of the cauchy development of a compact region there's gonna be some causality violations

and compactly determined is yet another thing

Basically that the intersection of the future of a cauchy slice and the past of a bit of the cauchy horizon is compact

skull petrol

Cool teacher, hey? @0celo7

0celo7

1:25 AM

@skullpetrol no

I haven't figured out what he's talking about yet

I need to investigate a theorem

Slereah

Is it the theorem about compact riemannian manifolds

or whatever

0celo7

inverse function theorem

Slereah

I do not know it

0celo7

me neither!

Slereah

Better investigate it then

0celo7

1:31 AM

yes

Slereah

1:45 AM

Help

I found something

Reprehensible

math.univ-toulouse.fr/~schechtman/defin-nova-preprint.pdf

2006 math paper in Latin

Alfred Centauri

2:14 AM

@TanMath and then others will ask you to do the same. I get this place; the fact that you don't means that you should get your own damn room rather than ask others to do so.

TanMath

2:51 AM

@AlfredCentauri you don't need to be insulting, understood? I am telling others to get their own chatroom because people are asking me to get a chatroom..is that fine with you?

0celo7

@TanMath Perhaps in our case multiple people are interested in the topic, and in your case only you were?

Dunno specifics.

TanMath

@0celo7 I don't see anybody interested in your topic...BTW, have you created a room (not to force you or anything, just want to know)?

0celo7

@TanMath @Slereah and I talk about CTCs and GR every day.

So there are multiple people interested.

TanMath

3:07 AM

@0celo7 if they are so interested, why is it that 3 people starred my post about you guys making yourself another room? You can't ignore that...

0celo7

@TanMath Then they should speak up.

TanMath

@0celo7 Doesn't seem that they did by starring?

0celo7

Nope!

TanMath

@0celo7 then why would they star? why?!

just like that?

0celo7

Maybe they're trolls. I don't know why they did it.

TanMath

3:12 AM

@0celo7 trolls?! do you call people like Danu, obe, and Ghost trolls? It seems that is your explanation for everything they're trolls

0celo7

Danu, Ghost and obe starred it?

TanMath

@0celo7 anybody in the chatroom or people who came to the chatroom starred it.. who else? Did you spot any trolls who joined the chatroom?

0celo7

Perhaps...

TanMath

@0celo7 who? give us the names! we have to tell dmckee!

0celo7

Maybe he is one of the trolls!

TanMath

3:15 AM

@0celo7 who, dmckee?

0celo7

Maybe? I don't know for sure.

In any case, the premise is wrong.

You can talk about other things.

Ghost

@0celo7 don't want to

TanMath

@0celo7 wat!! you call the moderator a troll? good thing @dmckee isn't here!

hey @DanielSank ! A long day over?

Coming to the h Bar to have a few drinks? @DanielSank

0celo7

@TanMath Nope.

I can't rule him out, of course.

TanMath

@0celo7 by saying "Maybe" you partially think he could be a troll...

DanielSank

3:20 AM

Hey guys, my coworker is seeing this chat for the first time.

Ghost

eh, I have called worse things than a 'troll'

DanielSank

I hope you'll be your usual... "charming" selves.

4

0celo7

@DanielSank Hello Google employee #2

DanielSank

@0celo7 Actually he's a UCSB PhD candidate.

0celo7

@UCSB person tell A. Zee his QFT book sucks

DanielSank

3:21 AM

@TanMath If there were booze here that would probably be a very bad thing.

@0celo7 Eh, no.

0celo7

He on this guy's committee or something?

Ghost

@TanMath if I am labelled a 'troll' I could not care less, @0celo7 has called me worse

0celo7

I have?

TanMath

@DanielSank he is also from UCSB?

Ghost

@0celo7 yes, you have - but thankfully, you stopped

TanMath

3:24 AM

4 mins ago, by DanielSank

I hope you'll be your usual... "charming" selves.

Ghost

I am always charming

0celo7

@Ghost I don't recall this, but ok.

Ghost

@0celo7 calling me 'satan' - it was getting irritating, hence rude to continue

0celo7

You're not Satan, why would I call you that?

I called that dude with the pentagram Satan.

Sorry if there was confusion.

Ghost

same person

0celo7

3:28 AM

...

Well that's unfortunate.

I quite like you. Sad to see you've turned to the dark side.

Ghost

I just changed my avatar, it was a pentacle (symbol for Wiccan and Pagan beliefs) - the upside down version is a symbol for satanism

the point is, I asked you to stop, but you continued - which was rude - but you have stopped

0celo7

I stopped because you no longer sport a pentagram.

In any case, let's return to the issue at hand.

@TanMath What topic should I be taking elsewhere? And why do you feel like you can't bring in your topic?

Ghost

@0celo7 whatever, kid

TanMath

@0celo7 IDK, I just feel ignored (this is the first time i am not!)

0celo7

You feeling ignored is not my problem or fault.

TanMath

3:36 AM

@0celo7 you know what? I am tired of this chat that is going nowhere...you do whatever you want to do, okay?

Ghost

he usually does

it is his way, or we are 'trolls' etc

0celo7

Why would I do anything else? Lol.

DanielSank

@TanMath Yes.

TanMath

@Ghost agreed!

@DanielSank you should show prof. mohseni this chat.. We can discuss about his wonderful research!

Ghost

@0celo7 hilarious...

@TanMath that'd be very cool!

TanMath

3:46 AM

@Ghost you know about him?

0celo7

@Ghost Hilarious?

I do what I do and I'm not going to let someone tell me what to do.

Ghost

@TanMath in passing, yes

@0celo7 that's fine, but you should show respect when people tell you to stop calling them something

TanMath

@Ghost cool! have you read his articles?

Ghost

@TanMath a few - a little while ago

TanMath

@Ghost really? so you must know about exciton energy transfer and the FMO complex?

Ghost

3:51 AM

@TanMath a little bit

0celo7

Take this to another room ffs

TanMath

@Ghost cool! something to discuss!

Ghost

well, I have significant gaps in my knowledge

TanMath

@0celo7 we haven't even started talkng real science, man! And just like you didn't listen to me, i will certainly ignore you...

Ghost

and we would need the lord and master of the chat room @0celo7's approval to dare discuss something he doesn't like

0celo7

3:53 AM

@Ghost Finally someone showing some respect around here.

Ghost

@0celo7 it was obvious sarcasm

TanMath

@Ghost who cares! apart from @MarkMitchison you are the only person who knows this stuff...

0celo7

@TanMath I listed to you.

TanMath

@0celo7 As I am a dictator, I don't need to show any respect if I don't want to...

0celo7

@Ghost That's sad.

Ghost

3:54 AM

I am going to put you on ignore @0celo7

TanMath

@0celo7 no you didn't...

0celo7

@Ghost Ok.

I'm not going to stop you!

TanMath

@Ghost I think I should too!

0celo7

@TanMath Really?

I responded to your points.

Ghost

easiest way, keeps the peace

0celo7

3:55 AM

How is that not listening?

TanMath

@Ghost I just pressed "hide posts" and it is like he doesn't exist!

@Ghost have you heard of FRET?

Ghost

in passing

TanMath

@Ghost me too.. Do you know why FMO dynamics haven't been analyzed with sinple MC-FRET? what do you think?

@0celo7 I am sorry if we are insulting, but we need to do something.. You listened, but you didnt yake action, and that is why I am angry

Ghost

I'd have to remind myself of everything before I could answer - have been focusing on a series of studies for my university contacts

in a different field

0celo7

@TanMath You have to try really hard to insult me.

TanMath

4:01 AM

@Ghost what is that?

0celo7

I have no clue what action you want me to take.

Ghost

manipulating the upper layers of a silicon image sensors

TanMath

@Ghost so you don't remember? I have been working on a project on the FMO complex only

Ghost

@TanMath it has been a crazy year - 4 different and disparate studies

TanMath

@Ghost oh ok.l guess there is not much we can discuss then...

I bet @0celo7 is rejoicing then...

Ghost

4:05 AM

for now - but will do so soon - I enjoy a good scientific chat

I would not know, I have him on ignore

0celo7

@TanMath Sigh, that was a joke

People can discuss whatever they like. This isn't my chat.

TanMath

@Ghost me too

@Ghost I hope as well... the FMO complex and photosynthesis in general is amazing! the nature's quantum computers

Ghost

@TanMath I wholeheartedly agree - and there are potential for practical applications too

TanMath

@Ghost yes!

Ghost

This is the kind of science I enjoy - delving into what is already present and replicating (and improving) for applications

TanMath

4:12 AM

@Ghost yes.. That is what is known as technology.. R&D

@Ghost to be honest, I think this is the only reason i wanted to research this stuff.. I am also interested in artificial photosynthesis.

Ghost

true - it's what got me interested in the first place

@TanMath absolutely!

TanMath

@Ghost it seems we are pretty related! same interest and same reasons!

Ghost

indeed - but I have to go for a while now - visitors are imminent

TanMath

BTW, I am really a biology guy, but am quite interested in physics... They are two interesting topics that when combined, leads to even more interesting stuff!

@Ghost you are leaving? goodbye then! nice talking with you! I enjoyed it!

Ghost

@TanMath likewise - we'll chat again soon!

TanMath

4:17 AM

@Ghost great! ttyl!

DanielSank

4:36 AM

@Ghost Don't let anyone tell you that you can't be a physicist and do that stuff.

People who tell you that have a very limited idea of what physics is.

You will probably meet people who will call that "engineering" as if it's a bad thing. A huge fraction of experimental science is improving the tools we have, and in a lot of cases it takes a physicist to do it.

3

Secret

In fact, the current trend even art people and business are also collaborating together to solve tough technological problems

http://pubs.rsc.org/en/content/articlelanding/2012/cp/c2cp23670b#!divAbstract
Speaking about quantum biology, you might be interested in this

TanMath

@DanielSank when will your bring prof. mohseni over? At least two people want him to come...

@Secret cool! thanks.. I just learnt that pH does not affect quantum coherence!

Secret

4:51 AM

btw, are you from UNSW or some other uni?

TanMath

@Secret no..why?

Secret

I see, because when I saw " I just learnt that pH does not affect quantum coherence!" i initially thought you might have learnt it from the research talk in our uni recently

Must be my memory mucking up because I might accidentally confuse you with another phD who study in my uni who participate in the above research

TanMath

@Secret no, i just learnt it from your article! the one you sent

@Secret you know anything about Quantum Biology?

Secret

nice

only very little, the best I know is that entanglement in the photosystems is one reason for the high efficiency of converting sunlight to chemical energy

I have not followed much on it recently, because my interest in my scifi sounding physics is much stronger

I do still follow biology (ecology, microbiology, biophysics etc.) researches in the background in my free time, along with other sciences

there are numerous researches going on in the field of artificial photsynthesis. Most of them are also tied to hydrogen fuel related researches

TanMath

@Secret but do you know the actual science and math behind it?

hello @dmckee !

Secret

5:05 AM

I do, considering I have a physics and chemsitry double major, plus some knowledge on microbiology

However, I cannot always retrieve them easily from the top of my head, compared to the non biology type physics, because my RAM allocation for them is not very high

dmckee

To emphasize Daniel's point above I'll note that the Nobel for physics has been given for purely equipment related improvements more than once.

3

TanMath

@dmckee true...

@Secret oh, another quantum biology person! Can you access that information now? ;)

Secret

mind you, I really have not look into much in the field recently, only keeping my awareness on it (which is one reason I can find that article), thus unlike non biology physics or chemistry questions, I am even less confident on the answers

What things you want to know about?

TanMath

@Secret well, I was interested about FRET... you heard about it?

Secret

I think I only first heard of it in that chemistry talk, not much I am afraid...

But let's see what I can dig up....

TanMath

5:12 AM

@Secret which chemistry talk?

Secret

http://www.chemistry.unsw.edu.au/news-events/events/2015/07/seminar-tuneable-light-harvesting-and-folding-photosynthetic-antenna

Just an internal postgraduate research talk in out uni, as all honours students will attend these to keep up to date with the research in the school

This one is a collaboration between the school of chemistry and school of physics

Prof. Paul Curmi (one of the authors in the papaer I reffered) is a professor in our uni and he taught me thermodynamics courses before

TanMath

@Secret cool!

Secret

his major interest is molecular machines and thermo flucturations involving proteins

http://chemwiki.ucdavis.edu/Theoretical_Chemistry/Fundamentals/Fluorescence_Resonance_Energy_Transfer

This for starters, I will see whether I can dig up some journal articles

http://www.ks.uiuc.edu/~melih/Clegg2010.pdf

Seemed to be a review paper of the technique...

http://iopscience.iop.org/article/10.1209/epl/i2003-00472-2/meta;jsessionid=98B944A2B1A9F53842E5B1132C43239B.c2.iopscience.cld.iop.org

This one is not so biology related, but shows how FRET can be applied in constructing quantum computers

TanMath

@Secret i have seen this one before, but saw no math, so didn't read it.. I will look at it again. Thanks man!

Secret

5:29 AM

PS Relevant part to quantum biology of my academic background in terms of the course I done in UNSW:
Background (Note to keep this list short, I have omitted my maths background in the list, but the short answer is linear algebra, solving ODE and PDE (wave, heat and laplace), multivariable calculus):

Degree: Bachelor of Science (Physics and chemistry)

Chemistry:
=================
Inorganic chemistry:
-----------------------------------
Electronic structure of atoms (molecular orbital theory on diatomics, isotope effects, bonding (intra and intermolecular), quantum numbers, overlap integra…

NeuroFuzzy

@0celo7 try really hard to insult you? Challenge accepted. Uh... ehm... some th ing about factoring quadratics... ODEs... something something general relativity... okay I give up.

TanMath

@Secret wow, you know a lot!!

0celo7

@NeuroFuzzy Something something GR?

Secret

having said that, as 0celo7 can tell you, I often suffer memory problems thus I cannot always recall concepts from the top of my head

0celo7

I don't find GR challenging.

Fucking quadratic polynomials on the other hand...

TanMath

5:34 AM

@Secret of course.. everybody is like that...

Secret

chemistry is slightly better because the relevant memeory was constantly being engaged due to me doing my chemsitry honours

and my no. 1 favouraite is chemistry also helps

TanMath

@Secret do you know about EET? BTW, do you know who prof.mohseni is?

Secret

no and no
I might came across some excitation energy transfer throughout my honours but right now not (yet)

TanMath

@Secret then how do you know the physics and quantum mechanics of photosynthesis without knowing EET? How did you do the modelling? Do you know about the frenkel exciton model and the lindblad equation?

Secret

As I said before, I only know very little of it. Most of the stuff I know about quantum biology is from the research talks held in the uni and also me browsing science magazine websites from my daily hobbies

While the above academic statement of my undergrad shows I have the foundations to read up and enrich myself on knowledge related to quantum biology, I am currently more focused on another field which is why I have not read up a much

You can pretty much said my background in quantum biology is:

"I am aware of this field, and know some of the major findings and possible applications, but I don't know the details on how the experiments and some of the theory carried out that are specialised in the field unless I read about them or learnt from the talks"

TanMath

5:45 AM

@Secret oh, i see.. i guess there is not much to chat about then...

Secret

i am sorry...

TanMath

@Secret we can talk about something else?

Secret

sure

what do you like to talk about?

Secret

(suddenly felt like I need 0celo7's presence to stablise the chat room...)

TanMath

@Secret him? why him?

@Secret QM i guess...

Secret

5:54 AM

no not that

TanMath

@Secret why not?

Secret

0celo7 is the most common user in the chat room, his presence sometimes helps make the chat messages look like they are in an unbroken flow

TanMath

@Secret 0celo7 do you even what he blabbers away about?

Secret

that fact that I know not enough quantum biology have caused a premature break in the above discussion flow, and because of my weird personality, this give me a very uncomfortable doomsday feeling

so commoners are needed to "stabilise" it

TanMath

@Secret huh? sounds like fake scifi movie scripts!

@Secret why do you keep doing that?

@Secret not that @0celo7 could prevent that!

0celo7

5:59 AM

@Secret What?

Secret

1) Well, I am a scifi freak also besides a science freak, and what they don't know about me until now is that I have a tendency to imitate scifi scenes
2) the --- helps separate two different of my messages, otherwise my usually long messages will pose trouble to other users reading it, confusing them

@0celo7 hi, (much better lol)

Secret

One of my most bizarre quirks of my personality is, like 0celo7, I don't like being ignored, but it is only the beginnning of this year that I discovered it also works the other way:

I also don't like when I cannot answer someone's question satisfactorily

to sum up, I hate when the flow of Q and A gets interrupted and broken, by whatever reason

and I get really nervous when that happens

The latter part is one of the major reason I ask questions more than answering in PSE

because I am not 100% confident on my answers, I don't want to mislead people

0celo7

@Secret I don't like being ignored?

I don't like being ignored by people I like.

I think this is normal.

Secret

well, I am similar

so yeah...

the bizarre part is: I don't like when I cannot answer someone's question satisfactorily

maybe because I am a perfectionist

vzn

6:14 AM

hi all really great article on fusion startups, cover story of Time magazine...

inside the quest for fusion, clean energy's holy grail / Time

Secret

non paywalled version?

vzn

oh oops meant/ forgot to mention that its paywalled sorry :(

looks like NYT recently covered it too though.

← have/ read archaic "paper" version

Secret

@TanMath 3) 0celo7 (or other regulars) cannot prevent me from not knowing enough quantum biology, but they can give me a sense of comfort with their presence that hep mitigate those unstable emotions generated by the nervousness

Secret

@vzn ok, shoudl have a check

vzn

similar article nonpaywalled

Start-Ups Take On Challenge of Nuclear Fusion / NYT

Secret

6:21 AM

i see, hopefully it is not another 50 years later thing. It is nice that small companeis are taking roles in the fusion problem.

The departure form tokamaks approaches seemed to be a promising direction, we'll see how it goes in a few years time

vzn

@Secret yes very enthused about this area myself. the articles discuss that. actually the time mag article was saying commercial power by 2040 earliest. but maybe prototypes before then.

TanMath

hello @vzn ! long time no see!

vzn

there seems to be a noticeable shift in the area akin to electric vehicles or space prjs done by private corps.

0celo7

@Huy Face me in honorable combat.

vzn

@TanMath hi TanMath, glad to see youre still into physics, maybe check out my last blog with lots of cool QM stuff, a bit on biology. :)

Huy

6:24 AM

1v1me

Secret

@vzn Are you a sciencedaily regular like me?

vzn

@Secret so secret you seem "mysterious"... do you have a phd? physics? yes do like to read sciencedaily a lot. mainly compsci/ math section. am also liking reddit a lot last few mos.

Secret

nah I am still in honours. My current chemsitry honours is related to molecular dynamics and photochemistry

I have my bachelor in physics and chemistry

vzn

ah ok! you write like a phd at times!

Secret

I planned to do phD soon

really?

vzn

6:28 AM

you are studying physics? or chemistry?

Secret

both

double major

vzn

nice!

"double your trouble" :P

Secret

well, as long you like the subjects, you won't lose your momentum

I study them because I like them

although physics is a bit more like an affair, honestly speaking, because of it as an important ingredient to my scifi

vzn

an increasingly relevant combination these days eg wrt photosynthesis, DNA, protein folding & other crosscutting emerging areas.

spking of scifi have you seen back to the future? just re-saw it recently & was (re) amused by the "portable fusion" reactor joke. its in the news because of the oct 2015 date in the movie.

TanMath

@Huy for what? why?

Secret

6:30 AM

artificial photosynthesis, metamaterials, quantum computing, microbiomes, organocatalysis etc. are some of the hot topics out there

Yes I have watched back to the future, that was when I was in my primary school period

vzn

ah, QM computing a subj near to my heart also.

its great to finally see the field start to really pick up after so many yrs.

Secret

I currently have some kind of model on time travel that is based on back to the future's time travel (and arguebly, that post of mine inspired by my model is the reason why recently the PSE chat room is filled with time travel discussion)

Secret

Strangely, my interest on QM computing is slightly less than QM

Probably because I am bad at computers

vzn

lol back 2 the future time travel is "hollywood time travel"... was thinking it seems to be loosely inspired by the (in)famous "grandfather paradox" except with "mother/ father" substituted for "grandfather"!

QM computing is defn very hard stuff.

its the kind of stuff that ties up even the Phds in knots.

Secret

indeed

TanMath

6:35 AM

@Secret when was this time travel discussion?

vzn

what do you want to do you phd in? physics+chemistry?

TanMath

@vzn physical chemistry!

Secret

let me check... (going to search engine) It all start with a discussion about interacting tachyons... whcih QMechanic joined breifly

Please wait...

TanMath

@Secret waiting...

Secret

@TanMath
http://chat.stackexchange.com/transcript/71?m=24238993#24238993
Before this point, the CTC discussion between Slereah 0celo7 and Acuriousmind are not very frequent, with many other users interspaced between them talking about other things

http://chat.stackexchange.com/transcript/71?m=24811698#24811698
This point is when the CTC discussion started to explode because possibly my comment about interacting tachyons inspired Slreah to ask this question and investigating intensely on CTCs afterwards (which before that he does it at a steady pace)

My current focus is time travel research because of my scifi, (and of course photochemsitry because of my honours (which in some way, is a means to get enough computational and QM background for my focus))

Put it in another way, while chemistry is intrinsic, my physics interest is at least 70% motivated by me wanting to complete my scifi

this is why I sometimes questions my relationship with physics

DanielSank

6:49 AM

@dmckee I didn't know that. What do you have in mind?

@TanMath I work rather far from him and I'm not sure it's sensible for me to email him a link to the chat room.

vzn

so DS did you cohort get a good impression of the chat room? (aka "peanut gallery") :P

Secret

As for the model itself I have never *explicitly* mentioned it anywhere in the chat room, because at its current state it sounds more like crank (in fact, one of the next step I want to do is to check whether it is compatible with GR, because if it does not it is unphysical and meaningless)

Acuriousmind and Slereah, however are aware that some of my miscocneptions and questions I asked related to the topic is inspired from that model

Secret

7:07 AM

Oh crap I should have delayed answering that question in red by staying in the blue branch a bit longer,

Dead chatroom again...

RPfnoR 25

John Duffield

11:29 AM

@AngusTheMan : I've given you an upvote for effort, but I'm not sure the OP will feel you've answered his question.

Secret

11:43 AM

I wonder how will one model the configuration space of sliding block puzzle games...?

this level is particularly interesting because the solution to it involve doing a certain sequence of move exactly twice (with the first try will basically swap the green and blue block into what is shown here, and the second try to slot the blue block into place so it can escape)

I wonder if one will model these using group theory, that the movement of the blocks and its collision detection rules are the group operations, and the blocks are the elements of a group

because whatever the underlying mathematical object that can model all possible configurations of this level, it seems to have some kind of orbit given how a sequence of move end up swapping the position of two of the blocks

alarge

@Secret Well given that people have pretty exhaustively modeled the Rubik's cube using group theory, I would imagine it be applicable here as well.

Secret

I wish I can mathematically investigate what a dead end move look like, because they often look magical to me as I don't know they are there until I hit those moves

For example, in this level, there's one key configuration that will result in the puzzle to become unsolvable (i.e. if you slide the green block out of the exit)

thus one can argue this is not a group, but something more general because the operation that lead to this configuration is not invertible

but otherwise, it pretty much act like a group

Slereah

12:26 PM

Hello

Secret

12:53 PM

hi

Slereah

Hm

I wonder if the plane with a handle can be defined with bispherical coordinates

Or somesuch

Secret

would torodial coordinate describe it better
https://en.wikipedia.org/wiki/Toroidal_coordinates

since an open plane with a handle is homeomorphic to a punctured torus, whcih is as shwon?