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12:27 AM
@vzn Is this a real thing that the site has decided to do?
If so I can probably do it Sunday, unless people want a week day.
 
@DanielSank You people on MIT Tech Review, fancy!
 
@BernardMeurer Yah.
 
@DanielSank I'll tell all the kids at school I know someone who was at that magazine
 
@BernardMeurer do you have a crush on me?
 
@DanielSank Yes. If you were woman I would have moved to Santa Barbara already
 
12:33 AM
I see.
 
@DanielSank Don't tell your fiancee, I don't want to make an astronomic enemy
 
@BernardMeurer ok
 
@DanielSank Dude, what is wrong with UCSD, they just sent me 5 emails about the same damn thing
 
@BernardMeurer Not sure.
Someone there might be bored.
Gotta go.
Catch you later, baby.
 
See ya love
 
12:43 AM
@Slereah This question has nothing to do with the Hairy Ball theorem.
 
vzn
1:23 AM
@DanielSank its real if someone/ anyone agrees to it & everyone else carries it fwd (not really requiring major work). ok maybe best to let the guest pick time/ day if the std mtg time is not convenient. can you pick a time on sunday 29th & then remaining time after you agree can be for announcement to stick on site somewhere (hopefully main page).
another idea for publicity: site community ad. that would be very cool/ ideal but requires some "serious" community cooperation (someone making it, and 6v!)
 
I think we should start a monarchy
I can be the queen, I don't mind
 
 
2 hours later…
3:01 AM
what could machine physicists can taught us about how to run an experiment...?
 
3:17 AM
@vzn I agree that a thing is "official" when someone just goes ahead and does it.
However, if people are going to to dedicate time to do an AMA it's best to make sure there will actually be an audience.
 
3:53 AM
@BernardMeurer I accepted my waterloo offer. :D
3
you better get in.
or else.
 
@3075 Congratulations.
 
@DanielSank Thanks
I chose waterloo because of perimeter institute and also their physics courses. ucalendar.uwaterloo.ca/SA/GRAD/1314/GRDcourse-PHYS.html
 
@JohnRennie This is a Rule of Internet: Every community has a few people who think the moderators are evil. These people blame the moderators for some amount of the communities problems. Maybe it's just easier than the alternatives.
 
@3075 Go molest the office of admissions people
I really want Waterloo
 
@BernardMeurer o.o
 
4:04 AM
because unless I get that fancy scholarship I can't go to UCSD
and if I can't go to UCSD I'll wind up somewhere random in this world
or Waterloo
:p
 
waterloo should reply by may 31st since it's the last day to apply for residence.
 
::stroking begins::
 
you should call them and make sure they're considering you.
 
@3075 I hit them an email after I got everything sorted to recheck it was all okay and they confirmed already
 
ok good.
 
4:10 AM
THEY JUST DON'T LOVE ME
 
did they say how long it would take?
 
They're not like @DanielSank
@3075 They gave the estimate on the website, until may 31st
 
oh cool
fingers crossed :D
 
user116211
@BernardMeurer: o/
 
user116211
Okay, I'm a bit confused....
 
4:14 AM
@3075 I'm dying, slowly and surely
@MAFIA36790 I have that effect on people
 
user116211
Is $\sum_{ij}$ same as $\sum_i\sum_j\;?$
 
no.
 
Don't think so, no
 
@BernardMeurer what will you do if you're denied D:
did you get in anywhere else other than ucsd?
 
@3075 Well if I get the scholarship I will go to UCSD
and transfer to UCSB later probably, because CEng is 'impacted' they say at UCSD so you need a 4.0 GPA to get in, which I don't think I will accomplish
 
4:18 AM
what if you get the scholarship and you get into waterloo? :(
 
If I get into Waterloo I'm going there, no question
 
ok cool. :)
 
If I get no scholarship and Waterloo rejects me I'll go to the University of Lisbon or Coimbra
over in Portugal
 
user116211
@BernardMeurer: Come to India then ;)
 
@MAFIA36790 I'm trying to escape the third world, not change scenes :p
 
user116211
4:21 AM
Hey, there are some of the best institutes in India; you can't deny that ;_;
 
@MAFIA36790 I'd disagree that they are some of the 'best' but I will wholeheartedly agree that they are very good
 
user116211
okay, okay. I don't know if you ever heard IITk, BARC, TIFC or CBS;damn.
 
user116211
But I really do want you get Waterloo; I'm seeing that torment for past one month :(
 
IIT yes
People use IIT exams to study here because of how good they are :)
 
vzn
4:49 AM
@DanielSank sigh, just do it... the regular chat room mtg time will have a significant audience just based on historical attendance, anything else may be more random, and nothing is guaranteed in cyberspace. if @DavidZ publicizes it on the home pg, think that will likely increase the exposure/ attendance. anyway 1st time, lets not expect fireworks, lets just see if we can pull it off, eh? and build on it each time...? sound reasonable? (invite your fiance etc for a guanteed audience, wink)
 
vzn
5:04 AM
@3075 congratulations, a real accomplishment! and as they say "now the hard work begins"! maybe you could put more info in your profile that might help reveal some of your presumably impressive qualifications!
 
47
Q: Why do grapes in a microwave oven produce plasma?

JBESome of you may know this experience (Grape + Microwave oven = Plasma video link): take a grape that you almost split in two parts, letting just a tiny piece of skin making a link between each half-part. put that in a microwave oven, and few seconds later, a light ball which seems to be a plasm...

 
@JohnRennie It's pretty cool to try, my school disagrees
 
If I were a teacher I would get all my students to do that experiment. If you've never seen it before it's absolutely amazing!
 
It was my salvation during boring classes :)
 
user116211
5:20 AM
WoW! Luboš is a history buff!!
 
user116211
Note that in the 1770s, it was harder to commute from America to Britain because there were no airplanes. ;-) If the Americans were a little bit more patient, I am pretty sure that a totally satisfactory full-citizen system would be achieved once the airplanes become common. — LuboÅ¡ Motl 20 hours ago
 
5:42 AM
@0celo7 does it not
 
@BernardMeurer Did you ever make nitrogen triiodide?
 
@JohnRennie I was banned from the lab during my second year of high school for suceeding in making HF
 
@BernardMeurer err, you do realise how dangerous HF is? Couldn't you have made something safer like cyanide or Sarin? :-)
 
@JohnRennie I had a mask on! And I was doing it inside the magic gas chamber!
 
Fair enough then!
 
5:48 AM
And it was a minimal amount too, I just wanted to see something dissolve glass :D
 
user54412
@BernardMeurer if HF gets on your hand, you either chop your hand off or you die
 
user54412
pretty nasty stuff
 
HF dissolves glass only slowly so it's not that spectacular. Mostly it just frosts the glass.
 
@JohnRennie I didn't know that at the time, now I do :v
@ChrisWhite I had gloves and all, and hey I was 15 I was about 30% more destructive than I am today
 
I worked for a bit at crystallising zirconium organophosphates from HF
 
5:53 AM
OH I HAZ QUESTION
I got in a massive discussion with a friend yesterday because he was saying that fire 'isn't matter'
and I know it is
is there any empirical way to prove this in a bar?
 
We have beer, matches, a lighter, smokes and paper near by
 
You need to agree on your definition of fire. Most non-physicsts think it refers to the heat/light not the hot gas.
 
That's my point! Fire is just hot gas
but I couldn't come up with a dumb proof
 
Well hot gas is present because you can see convection currents in the flame e.g. bits of ash rising. The point is that your friend will claim that's not the fire.
 
5:58 AM
So all I have to do is turn him into a physics major!
 
Actually the visible flame comes mostly from black body radiation emitted by particles of carbon.
Your problem is that non-nerds think fire is somehow mysterious
But then mankind has thought that for all of recorded history
Physics - spoiling people's superstitious fun for two millenia!
2
 
LOL
You get a marking on my beer list for that
I'll be off to bed now, night folks!
 
 
1 hour later…
7:17 AM
Hello
 
user116211
7:43 AM
Hallo!
 
8:26 AM
@JohnRennie Thank you because of your response. Don't you think those restrictions aren't enough? I think those make the users that don't answer the questions that their vote is zero or under. And as anyone that have 125 rep can downwote a question (and it is easy to earn 125 rep (considering the Association Bonus)), so it is possible that a good question is downvoted by those that don't have the competency for judging.
@JohnRennie I think it is better that the moderators or high rep users control the deletion of the questions. In other words, any OP cannot delete his/her questions without having permit from moderators or high rep users. Don’t you agree? :-)
 
 
1 hour later…
9:43 AM
@lucas If you read the link John gave you, you'll know that regular site members cannot delete their own questions when they have a positive-score answer, or multiple answers. This generally prevents people from removing other members' content, when that content is considered useful to the site.
 
9:55 AM
"It is well–known that"
No dammit
I'm reading this paper to learn!
Tell me the details!
 
@Slereah ahahah I also do that at times
however it is better to give the bibliographic reference
to contain all the details, an article would be $10^{\text{very large s**t}}$ pages long.
 
user116211
@yuggib And that's why they are articles and not books although there are articles that are self-contained.
 
user116211
I would say very few though.
 
@MAFIA36790 in mathematics, there is no article or book that is completely self-contained; apart (maybe) from bourbaki or set theoretical books that start from the very foundations
 
user116211
@yuggib I had the same in my mind ;P
 
user116211
10:10 AM
BTW, @yuggib, they would deliver Grillet day after tomorrow... I'm damn excited \o/
 
:-)
 
https://www.youtube.com/watch?v=gpM_rnQBCr0
I might either attempt this permutation proof, or (if failed) ask about it in MSE

gut feeling says the way they exchange business cards in this ad is the most efficient way for n people
 
user116211
Worldbuilding graduated!!
 
user116211
The best site-design ever I got to see ;)
 
10:26 AM
@yuggib Principia Mathematica is best
Although their way to handle the Russell paradox is a bit poor
 
@Slereah it is a bit outdated...actually bourbaki set theory is outdated as well
personally, I like either set theory by Jech
 
Is there a modern book like that?
 
or model theory by chuang
 
I only know metamath as a modern "Let's do all math without any reference" thing
 
well, any book that introduces to set theory does everything from scratch
 
10:28 AM
But you know, I'm not expecting something self contained
Just
Anything related to the Thirring model, write it out?
I don't want you to redo QFT
Just don't assume I know about bosonization or the Lorentz group in 2D
I can understand the need for references but it would be nice not to have to do the daisy chain of references until I find the correct explanation
That's why I want to write a QFT book sometimes :p
I don't want to have to juggle 5 different books to get a complete picture of it
 
user116211
@Slereah I would be the first one to buy it ;))
 
It will be called
THE UNIVERSE FROM SCRATCH
calls from Carl Sagan's lawyer
 
user116211
hahaha.
 
There actually already exists a paper with that title
There's a bunch of QFT stuff you basically never see really
Like anything related to quantum optics never appears in a generic QFT book
Also I find it a bit weird that like
Hydrogen atom is almost unheard of in QFT books?
Even the fixed nucleus limit
It's all scattering all the time
 
user116211
 
10:42 AM
Yeah that one
 
user116211
Maybe JD could tell... he wrote a book though...
 
The best book
One thing I find annoying in some books is the habit of putting hugely important parts in the exercize section, without any solution
 
user116211
@Jolenealaska: Did anyone flag anything?
 
user116211
@AnkitSharma: o/
 
Ignore me, it was mistake ;D
in Mos Eisley, 2 mins ago, by Rand al'Thor
Sounds like a question for the h Bar?
 
11:03 AM
what is even a Lorentz transform in 2D
Let's see
$t' = \cosh(\phi)t - \sinh(\phi)x$
$x' = \cosh(\phi)x - \sinh(\phi)t$
 
i think that's just a hyperbolic rotation in 2D ?
 
Yes
Or
$(u',v') = \text{diag}(e^\phi, e^{-\phi}) (u,v)$
$\text{diag}(e^\phi, e^{-\phi}) \text{diag}(e^\theta, e^{-\theta}) = \text{diag}(e^{\phi+\theta}, e^{-(\phi+\theta)})$
Which sounds fine for group structures and all
 
diag? but the above 2D lorentz matrix is not diagonal?
 
It is in null coordinates
 
https://en.wikipedia.org/wiki/Light-cone_coordinates
hmm, I wonder if I can use these to probe the causal structures of some arbitrary spacetimes (as long it has a null hypersurface) easily compared to cartesians?
 
11:14 AM
You can't turn everything into null coordinates in more than two dimensions, though
It is useful though
Oh boy
 
what prevents that in > 2D?
and wow, "square root of vectors??" (must get a read to see what they have to say)
 
Well you only have one timelike direction to work with
That's 2 null directions max
 
ok makes sense
@MAFIA36790 That paper seemed to have CDT as a central subject, just noticing
 
11:45 AM
Where is ACM
 
user116211
I would say:
 
user116211
> Where is 0celo7 ?
 
if any of you would like to have fun, there is a new question on aviation.se that contains "a few" physics misconceptions: aviation.stackexchange.com/q/27603/1467
 
@0celo7 can't help me now
 
12:32 PM
@Federico indeed, though I would imagine the people who know how to answer such a question properly are probably already on Aviation
It's really about how aircraft work; the physics is merely incidental
 
@MAFIA36790 : I can't tell you how to get a universe from scratch. But I can tell you there are some big issues with the abstract of arxiv.org/abs/hep-th/0509010. Why don't you ask a question about it? Then I'll elaborate.
 
12:49 PM
@MAFIA36790 I just noticed that it is not a CDT paper, it is in fact THE first CDT paper
So Causal Dynamics Triangulation begins with this conference and this paper that follows it...
 
1:19 PM
@JohnDuffield that falls in the category of things we'd rather not have you posting here
 
@Slereah Ask on Skype if you need something.
 
1:37 PM
@David Z : that's why I said why don't you ask a question about it? By the way, when are you going to lift this unfair censorship imposed on me without warning. 0celo7 has served his time, why should I endure a life sentence?
 
user116211
2:28 PM
I know someone who has 3 professorships and 2 doctorates. His title is Prof. Prof. Prof. Dr. Dr. — Dave Clarke Jun 1 '12 at 8:32
 
user116211
WHO'S THAT GUY?
 
@vzn Your "just do it" attitude is typical of someone who's never traveled hundreds of miles and spent many hours preparing for a conference/talk/etc. only to find it poorly organized and/or the audience lacking.
I am happy to do what you describe, but not only super short notice and in the total absence of advertising, etc.
If you think I sound like a snob, then you're probably right, but it's a learned behavior, not an innate one.
@MAFIA36790 o/
 
@Slereah I have been summoned. What is your request?
 
Save us from evil.
 
@BernardMeurer lol. How did you have access to a microwave during a philosophy class?
 
2:43 PM
@ACuriousMind He was at home. The real question is how the administration found him.
 
@DanielSank That task might be a tiiiiiiny bit too big for me ;/
@DanielSank I'd rather be wondering why they seem to have taken more offense at him microwaving grapes than him skipping class
 
@ACuriousMind Even with asymptotic series?
 
Are grapes sacred in Brazil?
 
@ACuriousMind Perhaps. @BernardMeurer?
 
@DanielSank I'd say those are evil themselves
They work, but they really shouldn't!
 
2:52 PM
I once read in the forward of a textbook that an author never finishes a book, they rater abandon it.
I think this is true also of journal papers.
 
@acuri what do you think is better for new students to physics: model SHM with a well-known periodic function like sine/cosine or to model SHM with a more general periodic function that would be constructed?
 
@DanielSank what is your view on this issue?
http://journals.aps.org/pre/abstract/10.1103/PhysRevE.93.032147
 
I feel like the latter would give the students experience in abstracting physical phenomena with math
 
@Obliv Probably best to start with a sine wave and introduce the more general stuff afterwards.
The problem, of course, is that at the stage that most students first encounter harmonic motion, they don't know enough mathematics to treat it in generality.
 
True
 
2:56 PM
@Obliv I don't understand the question. You don't "model" the SHM with sine/cosine, you model it with the equation of motion and find that the solutions are sine/cosine/linear combinations thereof. What do you mean by "modelling" it with a more general periodic function?
 
I remember when I learned the how to deal with arbitrary phase, damped, driven oscillations as a freshman in college. It was the hardest part of the entire course because it was done in the typical "differential equation" style rather than just using a damned Fourier transform.
This happened, probably, because the textbook writer didn't assume the reader knew how to use Fourier analysis.
@Secret I'd have to actually read the paper.
Can access it at the moment.
 
@Secret However, even without reading it I'd bet you that when they say "apparently breaking the second law of thermodynamics" it's a dumb way of saying "if you ignore part of our system it appears to violate the second law of thermodynamics", which is not surprising.
@BernardMeurer <3
 
@BernardMeurer quest...
 
@DanielSank <3
@3075 DOING IT
@3075 Nuthing
 
2:59 PM
@Secret Oops, meant to say "cannot" access it at the moment.
 
oh well
 

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