« first day (2443 days earlier)      last day (2493 days later) » 
00:00 - 15:0015:00 - 00:00

12:44 AM
@ACuriousMind got the empress ending
Wonder what I did wrong
Wtf, because I visited the emperor
Laaaame
 
 
5 hours later…
6:15 AM
Yeah! You know me.
 
user228700
6:35 AM
@JohnR: Hi :-)
 
Morning/afternoon
 
user228700
I'm so sorry about yesterday! :-o
 
Academic bureaucracy safely dealt with? :-)
 
user228700
^ Yes :-) I had been waiting in line, you see, and they called us while I was talking to you.
 
I guessed that's what had happened.
 
user228700
6:37 AM
After that, there were many more things to do and then some more.
 
Well, it was kind of obvious :-)
 
user228700
:-) Ah. We even had a look at the hostel and all. Wait, I'll show you a picture of my room-to be:
 
Ah, I was going to ask if you'd seen the hostel.
Well, what do you think of it?
 
user228700
 
Looks nice. Obviously rather bare at the moment ...
 
user228700
6:41 AM
On the left side, there are two tables and a small door leading to a tiny bathroom.
 
user228700
@JohnRennie Nice?! It looks a little like a prison cell :-(
 
Having your own bathroom en suite is great. For three years I had to walk down two stories on a cold stone staircase to get to the bathroom.
@Kaumudi.H Well you haven't put up any posters, pictures and whatever other clutter teenage girls are prone to :-)
 
user228700
@JohnRennie Yes, yes, I agree.
 
The room has no personality yet. It's probably lonely :-)
 
user228700
@JohnRennie I don't have any posters or pictures or other clutter to take with me!
 
6:44 AM
The beds are quite close together. I hope your room mate doesn't snore :-)
 
user228700
:-o I hope so too!
 
The room is pretty basic, but for students the room is just somewhere you sleep. You work in the library and socialise in, well, I'm not sure where MEC students socialise.
 
user228700
And the subordinate warden, with whom we met first, is a little...out of it. She kept complaining about the superior warden to us and kept on mumbling.
 
That adds character :-)
 
user228700
What, lunacy? Oh, sure, but it was a little scary. The whole thing was scary.
 
6:46 AM
She's a water buffalo reincarnated as a hostel warden. Behaving that way is natural.
 
user228700
@JohnRennie Neither am I, actually :-/ And I dunno if we're allowed to stay back at the library till late hours in the night.
 
user228700
@JohnRennie Well, yes, but I don't know how I will be able to spruce things up. I have clothes, books and a few electronic gadgets to take with me, that's all.
 
I wouldn't be too downcast about the room. Once you've had a chance to get to know the town you can start looking around for a nicer place to stay.
 
user228700
I am thinking about buying a corkboard to put up pictures of my family or something but I don't have any more than two pictures with me.
 
user228700
@JohnRennie No, I don't think so; I'm stuck there for a year at the very least.
 
6:49 AM
The first year is going to go pretty quickly. Or at least it did for me.
 
user228700
@JohnRennie *City. It's a beautiful city and it is even (somewhat) connected by the metro.
 
You should see the place my brother had to stay when he was at college. It was so bad even the rats had left.
 
user228700
Oh, geez!
 
I think a lot of the undergrads move to somewhere else after their first year
a prison cell is a perfectly nice place to live in though
 
He was at Imperial College in London and accomodation was ridiculously expensive in London even in those days.
 
user228700
6:50 AM
@JohnRennie Ah, yes, I remember.
 
user228700
@BalarkaSen Not if you must share it!
 
All he could afford was a room in what was basically a slum, and he had to share it with two other students.
 
Kill the roommates. Kill them. Kill them and give us Channel 83.
 
Kill them, hide the body then eat them. Saves on buying food
Ah, I forgot you're a vegetarian. OK, don't eat them then.
Are there nicer rooms in the hostel or are they all basically cells? I ask because you might be able to reserve a better room for next year if you book early.
 
6:53 AM
... you and your weird films.
 
mornin
 
Sid
Good afternoon folks!
@Kaumudi.H That seems like a pretty good room for a hostel.
I mean, you don't expect to get 5-star rooms in dorm right?
 
@Kaumudi.H how much is the room costing you?
 
user228700
6:57 AM
Sorry about that, I was eating a bunch of chocolate.
 
Sid
Also, if you have a bathroom with you too, that is an added bonus. Most Govt.colleges have rooms such as that but without bathroom.
 
@Kaumudi.H got to get your priorities right :-)
 
user228700
@BalarkaSen Hmm. My parents might move to the city next year so I might even move back in with them.
 
user228700
@JohnRennie No, all rooms are similar, I think. And not all of them have the added bonus of an attached bathroom so I really did get quite lucky.
 
user228700
@JohnRennie YES :-P I hadn't eaten anything in over 16 hours, sorry.
 
6:59 AM
You've just eaten chocolate for breakfast????
Actually, I think I approve :-)
 
user228700
@JohnRennie That's the spirit! :-P I had feared that u'd changed!
 
@BalarkaSen what's channel 83 about?
 
user228700
@JohnRennie No, but I did have two tiny dosas as well. Chocolate, dosas and some aloo bhujia for breakfast/lunch!
 
Sid
@Danu Happy Brithday!
 
Chocolate dosa. Better than chocolate pizza I guess.
 
7:02 AM
Thanks
 
user228700
@Sid Well, yes, but it looks...none of it looks homely. This is to be expected, of course, but it adds to the homesickness that I have begun to feel already!
 
user228700
@JohnRennie Rs. 5,500 every month, including food.
 
Sid
That is slightly greater than 80 US dollars (In case anyone doesn't know about rupees)
 
In the UK that would be extraordinarily cheap. How it compares in Kerala I don't know.
 
@Danu are you going to have a party?
 
user228700
7:03 AM
@JohnRennie It's quite reasonable.
 
Sid
and should be around 60 Pounds(I think)
 
user228700
@JohnRennie NO!! Dear God, no! I had dosa with podi and then I ate some chocolate.
 
Sid
@Kaumudi.H Be prepared that food will be terrible.
 
@Danu Congrats, officially.
 
user228700
Chocolate dosa would be the greatest abomination of all.
 
7:04 AM
@Kaumudi.H the room is pretty bleak, though I was avoiding saying so in case you were feeling bad about it. But honestly college is such an exciting place the room isn't going to matter.
 
Sid
@LasVegasRaiders We're all invited right?
 
@Sid if he wants.
 
And to be fair, if you're going to a strange town that you don't know it's good to have somewhere safe and secure arranged for you.
 
@LasVegasRaiders no
 
College can be scary enough without worrying about the room as well.
 
user228700
7:06 AM
@JohnRennie Thanks, I appreciate that :-( It is the strangest city and I don't know very many people there.
 
Yet ...
 
Light a candle and blow it out at least, the one for good luck pal @Danu :-)
 
user228700
@JohnRennie Yes. Hmm. Are u terribly busy at the moment?
 
No, in fact I finished the first stage of the mornings work early so I'm currently sitting around drinking coffee
 
Sid
Each particle also has a password which allows its properties to be changed, but the cosmic censorship hypothesis suggests we can never observe the password itself—only its secure hash.
3
Daily XKCD plug in
 
user228700
7:08 AM
@JohnRennie Ah :-) How's the coffee?
 
Sid
LOL for the last one...
 
Coffee is always good
 
Sid
except when it is bad
 
Even bad coffee is good. It's like ... erm ... never mind :-)
 
@Sid did you listen to mc hawking on entropy?
 
7:10 AM
@Kaumudi.H anyhow, have you sorted out what the hostel supplies and what you need to bring?
 
Sid
@LasVegasRaiders No.
Today's Breaking News on Twitter. White House has spelt "inaccurately" inaccurately during a video attacking CBO for being inaccurate.
7
 
Just replaced the motherboard in this, and it actually works :-)
 
user228700
@JohnRennie Huh?
 
user228700
@JohnRennie Nice! :-)
 
user228700
@JohnRennie I think so. We're still buying; mum's looking for a first aid box for me rn.
 
7:15 AM
@LasVegasRaiders We'll see :P
 
@Kaumudi.H It's a Nexus 9 tablet I bought cheap on eBay because it was broken. I've managed to replace the motherboard and now it's working perfectly again. I could sell it and make a profit, or I could add it to the pile of electronic stuff I can't bear to part with. Guess which I'm going to do :-)
 
user228700
:-)
 
@JohnRennie Send it out to another lucky h bar user? ;)
 
I would take it.
and then sell it and make a profit
 
user228700
@JohnRennie No, you will wait till you find someone in need of it and generously ship it to them for free :-)
 
7:17 AM
@Kaumudi.H I've already given away four of these tablets and I'm running out of people to give them to.
 
Actually @JohnRennie maybe, sometime in the coming months, I will ask you a bit about advice regarding tablets... I'm considering buying one...
 
Sid
And I am thinking about buying a new Mobile Phone
 
user228700
Mar 21 at 7:36, by John Rennie
It's got to the point where people run away when they see me approaching carrying a laptop :-)
 
user228700
:-)
 
@Danu Tablets are basically toys. They fit uneasily between laptops and phones. I only use mine for reading books and occasional forays onto the web when I'm sat in my armchair and can't be bothered to walk over to the laptop.
 
7:19 AM
dammit bourgeoisie
you technological cyberpunks
 
user228700
@BalarkaSen You Russian existentialist.
 
@Danu They're also good for streaming video to your TV if you have a Chromecast enabled TV or an adaptor. Otherwise I'm honestly not sure why people buy tablets.
 
@BalarkaSen go find out what's on channel 83 :P
 
Actually people don't buy tablets any more. The tablet market is dying - even iPads are no longer selling.
 
@LasVegas channel 83 is like hardcore pornography watching which gives you brain tumor
 
7:22 AM
@Sid there are loads of really good cheap phones available in India at the moment.
 
Really?
 
Sid
@JohnRennie Any recommendations?
 
that's what the movie is about
 
7:22 AM
@Sid what sort of price? Entry level, mid range or high end?
 
user228700
@JohnR: Ah, now you're engrossed in this discussion about gadgets! I was going to ask if you could pop over to gchat for a bit.
 
Sid
Anything around Rupees 10,000 should do.
 
I'm just killing time. I'll head over to gchat now ...
 
Sid
Also, more importantly it should be 4G and have a good battery life
 
user228700
@BalarkaSen So exactly how would I give you Channel 83?
 
user228700
7:24 AM
Context:
 
user228700
32 mins ago, by Balarka Sen
Kill the roommates. Kill them. Kill them and give us Channel 83.
 
it's a dialogue from the movie
 
Sid
Hopefully dual sim too(but nowadays all phones are dual sim). I don't care about anything else
 
Yeah, but it doesn't make sense now @BalarkaSen
 
user228700
@BalarkaSen Ah.
 
7:25 AM
Give us a porn channel?
 
Sid
@JohnRennie Those are the specifications
 
It's not just a porn channel; watching it gives you brain cancer and you die. Totalitarian fascists buy off the channel to show it to the public in North America to ideologically purge and make it pure
 
Is there a porn stack exchange
 
It's a very political movie, mixed in with techno surrealism
 
Try to start one on Area 51. The effects of Internet porn on society.
 
7:30 AM
@Sid I don't know enough about the Indian market to make a recommendation, but most of the Chinese phones are dual sim and they are mostly pretty good.
 
The chat room could be called Channel 83.
 
another fantastic political horror film I watched recently is Enemy
brilliant
 
I doubt Christianity.SE, etc would approve
 
@JohnRennie So really, the reason I'm thinking about it is because some people here have tablets that they use as note books. This seems really handy to me.
Basically, I was thinking that if I get one with a big screen I could use it as a note book (by note book I mean the paper thing, not the new word for laptop). At the same time, I could use it as a light-weight replacement of a laptop for TeXing (using some kind of keyboard thing) and internet.
I don't typically do very "heavy" stuff on my laptop.
 
That's what I use my mini ipad for.
 
7:37 AM
Modern laptops are little larger or heavier than tablets, and they're faster and have a decent keyboard. Given the choice of a tablet or a (probably cheaper) Chromebook there's no competition. I'd go for the Chromebook every time.
 
@LasVegasRaiders Mini ipad seems too small
@JohnRennie OK
 
Sid
yeah, well.. I have like less than a fortnight for college and I need to buy a phone soon..
 
@JohnRennie I don't like the idea of having to do everything online though.
Don't chrome books rely on being online or something?
 
Chromebooks can work offline just like tablets.
 
A'ight
 
7:41 AM
I value my tablet and wouldn't be without it, but its uses are somewhat niche.
 
I like the mini pad because it fits in my pocket.
Barely.
Which is the ultimate in portability, for me.
 
@LasVegasRaiders large phones have taken over from small tablets. That's why iPad minis aren't selling these days.
 
@LasVegasRaiders Which is why you can't write on it properly...
 
Yeah, I'm a dinosaur.
 
By write I mean write by hand, on the screen.
 
7:47 AM
@Danu Good point
 
I want to write examples before properties, to use the examples to illustrate the properties
But I want to write the properties before the examples, to give the properties of the examples
The pain
 
The dilemma
 
@Slereah Do the examples first.
Or perhaps even better, give examples picked specifically to expose the properties clearly
then list them explicitly as general properties afterwards
(with proofs, of course ;D)
 
don't write anything at all [disclaimer: not helpful]
 
Go back to watching channel 83
 
7:51 AM
I agree that one should do examples first though
 
^me too
Unless the examples are "trivial."
 
One of the example is the complete feather
A homogeneous non-Hausdorff manifold
Is it trivial
 
it's a cute manifold
 
0
Q: Renormalization

krishnaI have done renormalisation of phi^4 theory and now i want to do it in phi^3 theory ,ihave done calculation with potential V(phi)=gphi^3/6+hphi. but unable to do it for two point and three point function calculation and also want to regularise the graphs by dimensional regularasation technique.

Too broad?
 
8:26 AM
@Qmechanic Yeah, I think so, it's effectively asking for a multi-page worked example of renormalization
 
8:43 AM
Hm
Non-Hausdorff manifolds are all $T_1$
And the Hausdorff property is like $T_4$ I think
Do they obey $T_2$ and $T_3$?
Let's check
Oh wait, $T_2$ is Hausdorff
nevermind
$T_4$ is normal Hausdorff
 
9:08 AM
@Qmechanic @ACuriousMind Yeah, I agree.
 
9:23 AM
@0celo7 Why do you think you did something "wrong"?
 
10:06 AM
1
Q: Should we rename the teleportation tag to quantum-teleportation?

Emilio PisantyI'm pretty sure there's a formal mechanism to suggest tag synonyms but I can't find it and no one ever votes there anyway, so: should we rename teleportation to quantum-teleportation and make the former redirect to the latter? It would make it equally easy to find and relatively clearer on wh...

 
10:41 AM
I dont like your new avatar
 
@JohnRennie Just FYI, next time people start a comment discussion about the heat death of the universe on an answer of yours about chicken breasts, it would be totally okay to flag that ;P
@AccidentalFourierTransform Sucks to be you, then.
 
That's not a terrible avatar
 
In mathematics, the Korteweg–de Vries equation (KdV equation for short) is a mathematical model of waves on shallow water surfaces. It is particularly notable as the prototypical example of an exactly solvable model, that is, a non-linear partial differential equation whose solutions can be exactly and precisely specified. KdV can be solved by means of the inverse scattering transform. The mathematical theory behind the KdV equation is a topic of active research. The KdV equation was first introduced by Boussinesq (1877, footnote on page 360) and rediscovered by Diederik Korteweg and Gustav de...
> The KdV equation has infinitely many integrals of motion...
 
@ACuriousMind :-)
 
10:47 AM
cool stuff
 
I nearly died of laughter imagining a foreplay babysitter. — Anixx 13 hours ago
 
( ͡° ͜ʖ ͡°)
 
11:39 AM
I wonder if there is a limit on how many times you can measure a quantum state, like, an entropy argument. I guess I need to revise von neumann entropy a bit
 
@Secret What do you mean by a "limit" there? Measurement needs some time, so you're limited in the number of measurements you can do in a given timespan by the duration of the measurement itself. why do you think entropy has anything to do with it?
 
Well, a very simple conceptual question is, does performing quantum measurement increases the entropy of the system or elsewhere, or it does not lead to a change in entropy
This is because every projective measurement you projected the state into some eigenstate, thus something will be "lost"?
 
@Secret Since an ideal projective measurement will often project into a pure state (it can't produce a mixed state if the target spaces of the projectors are one-dimensional) , the entropy after such a measurement is zero.
 
11:56 AM
Hmm, I see, and I guess the entropy reduction in the system is offsetted by the entropy increase of the detector due to now after measurement, the quantum sytem and some pointer states of the detector become entangled?
 
@Secret It's not clear that the second law holds at all in its naive version for quantum mixed states.
Thermodynamics usually does not include measurement - and you have to realize that the "collapse" into a pure state is also a result of not describing the measurement apparatus quantumly.
If you want to talk about the balance of entropy, you've got to descibe everything quantumly, and we're at discussing the measurement problem. Again.
 
ooooooops
 
And also, just having some mixed state and measuring it is not thermodynamics - you'll have to have stuff coupled with heat baths and so on for that.
 
12:11 PM
hmm...
Perhaps I have not understood enough, but I found it surprising that there is no function(?) that actually encodes all possible interactions so that we don't need to sum them up one by one. Perhaps there are infinitely too many interactions to wrote some kind of closed form for it, or maybe that's really what we are after and we said that function is the S matrix.

Still, given those asymptotic assumptions, I felt the S matrix does not fully describe the field, but what is a better alternative. Numrically trying to solve these interactions takes roughly months of supercomputing power, I am
It would be cool if there's a single mathematical object that took account of all the possible interactions so we can "count them all in one step", but I guess functional integrals makes that very difficult if not impossible
That's my expectation on what a mathematical description of a quantum field be, similar to how in general relativity, the metric and the stress energy tensor contains all the information in one single package, so to speak
In quantum mechanics, we have (rigged) hilbert spaces to play that role, thus things are still relatively manageable I guess...
One reason I cannot be a good physicist is because I _just _ cannot _ stand _ approximations
 
The process of learning is an "approximation."
 
@Secret I have no idea what you're talking about, and posting a screenshot of a video you haven't given a link to helps no one understand anything better
What is that picture of a YouTube video supposed to tell me?
 
12:26 PM
https://www.youtube.com/watch?v=oQ1WZ-eJW8Y

In that section, the guy is describing electron scattering and the many ways the interaction can occur, from exchanging one virtual photon, to 2, to 3 etc. Like what is gone through in my QFT class, the overall probability amplitude of the interaction is calculated by summing up all diagrams perturbatively
 
rob
@LasVegasRaiders There's some truth to that, but it's not the whole story.
 
and in respond to that, I have the above thought of finding one mathematical object that can account for that summation need to be done in one single package. But at this stage, its just a trailing thought that I might refer back to it later when I have a clearer mind on what to do with it
 
13
A: How can there be multiple irreducible representations of a group each having distinct dimension?

Jack SchmidtSO3 is a wonderful group, but it quickly got bored rotating vectors in space. It wanted to be used to help solve differential equations, and so desperately wanted to act on functions. Then one day, it realized it could act on functions by acting on their input. For instance, it contains a 90 d...

^ fantastic answer
 
Indeed, it's just a first approximation @rob and hello :-)
 
@EmilioPisanty And then you realize that spherical harmonics are just the restriction of these harmonic polynomials to the unit sphere...
 
12:35 PM
@ACuriousMind for me it's more "and then you realize that spherical harmonics are taught in the wrong way all the time for unknowable reasons". What they are is just those polynomials and it's a disservice to students to go in through the associated-Legendre-function door
but anyways, I had a question for you
 
@EmilioPisanty Yes, that's what I feel, too!
 
what's the precise relationship between the representations of $\rm SO(2)$ and the complex plane?
i.e. I want to say "I'm interested in the octupole moment of this object but because this is just 2D I can bugger off and just study $(x+iy)^3$"
 
Um, well, $\mathrm{SO}(2)\cong\mathrm{U}(1)$, so that group is just the unit circle in the complex plane
Furthermore, since it is Abelian, you know that all irreducible representations will be one-dimensional, i.e. the complex plane
 
and I want to phrase that "because" in a bit fancier language if it exists
@ACuriousMind do you? I'm primarily interested in representations over $\mathbb R$
 
[More thoughts about that video (link already provided above)] Hmm, so we have not figured out the underlying physics law that will place restrictions on loop diagrams to prevent the self energy from diverging without renormalisation yet...
 
12:38 PM
@EmilioPisanty Hm. Then I'm afraid I don't really know what you mean by a relationship between $\mathrm{SO}(2)$ and the complex plane (beyond what I've already said)
What made you believe there is one?
Oh, wait
 
[Even more thoughts] Let me google and see whether there are descriptions on the proportion of the measured mass of an electron that is contributed by the self energy...
 
Whether you're over $\mathrm{R}$ or $\mathbb{C}$ doesn't really matter, the real representations are the same as the complex representations - whether you say "the complex plane" or $\mathbb{R}^2$ doesn't make a difference
 
@ACuriousMind yeah, exactly
I'm sort of seeing $\mathbb C$ as a vector space over $\mathbb R$
 
So, um, what exactly do you want to know?
 
does the representation $(\theta)\mapsto e^{im\theta}$ have a specific name?
 
12:43 PM
I don't think so - it's..."the representation of $\mathrm{U}(1)$ labeled by $m$"?
 
@ACuriousMind "labeled"?
 
Well, like we label an $\mathrm{SO}(3)$ representation by the value of $L^2$, we label $\mathrm{SO}(2)$ representations by that value of $m$ there
 
Is "exponential" too vague?
 
hmmmmmm.
So I have some function $\mathbf F:[0,2\pi)\to\mathbb R^3$ (but in practice reduced to $\mathbb R^2$) and I'm interested in its moments $\int_0^{2\pi} \mathbf F(t)^{\otimes k} \mathrm dt$, but those are hard to analyze so I separate them into their component irreps of $\rm SO(n)$
and I have fancy multipolarly-transforming bases for the tensor spaces and so on
but in 2D all of that turns out to be unnecessary fluff and you can just focus on $\int_0^{2\pi} (F_x(t)+iF_y(t))^{m} (F_x(t)^2+F_y(t)^2)^{(k-m)/2}\mathrm dt$
and I want to be able to say "because $\mathbb R^2\cong \mathbb C$ and all that jazz"
but that feels... inelegant
 
Hmmmm
From a purely algebraic standpoint, that doesn't sound right.
 
12:52 PM
@ACuriousMind how come?
 
Even when $F$ is only a 2D vector, e.g. $F^{\otimes 3}$ lives in an eight-dimensional vector space.
But if you claim you can replace $F$ by its associated complex number, then $F^3$ (and any other power or product) clearly still lives in the two-dimensional complex plane
So the latter version obviously contains less information than the former
 
@ACuriousMind No, the full tensor space is eight-dimensional, but this is the fully symmetric subspace
and that's four dimensional
 
@EmilioPisanty Ah
 
[Some final thoughts on the video] I suspect for each renormalisation, you need an experimental value of the effective mass at some given conditions cause I guess we don't expect the effective mass to be the same in different systems
 
so, two dimensions on $m=3$ and two on $m=1$
 
12:56 PM
Ah, so you decompose your tensor space into the sums of irreps, then use that every irrep is isomorphic to $\mathbb{C}$.
Gotcha, that works
 
(corresponding to the symetrized parts of $x\otimes x\otimes x$, $x\otimes x\otimes y$, $x\otimes y\otimes y$ and $y\otimes y\otimes y$)
@ACuriousMind yeah
so I just say "since every irrep of $\rm SO(2)$ is isomorphic to $\Bbb C$ with the action $\theta\mapsto e^{im\theta}$"?
or something close to that?
 
Well
Thinking about it, it is a bit more subtle than that
 
@ACuriousMind in what way?
 
Thinking some more about it, it isn't :D
 
@ACuriousMind lol
 
1:04 PM
I had to check whether the real irreps of $\mathrm{SO}(2)$ are really isomorphic to the $\mathbb{C}$-reps
 
yeah, there's the issue of reducibility over $\Bbb R$ vs over $\Bbb C$
 
Because the "naive" way to get complex representations out of real ones is to complexify, but then $\mathbb{R}^2$ becomes $\mathbb{C}^2$ and you get the complex rep with $m$ and the complex rep with $-m$
 
@ACuriousMind yeah, but that's not what you want here
 
But the real rep with $m$ is just directly isomorphic to the complex rep with $m$, that's what confused me
 
@ACuriousMind or maybe this is just mangling the terminology from the beginning, and you can't really speak of isomorphisms between vector spaces over different fields?
 
1:06 PM
@EmilioPisanty I can certainly just think of the $\mathbb{C}$ rep as a real representation
Forgetting the complex structure is an allowed operation
 
yeah
so you take the $m$ representation over $\Bbb C$, and then you see it as a real-valued vector space
and then... it's irreducible over $\Bbb R$?
but then it doesn't have a well-defined $m$
 
Yep - it's precisely the $m$-representation over $\mathbb{R}$, by which I mean the rep $\theta\mapsto \begin{pmatrix} \sin(m\theta) & \cos(m\theta) \\ -\cos(m\theta) & \sin(m\theta)\end{pmatrix}$
(position of minus sign controversial ;) )
 
until you complexify that, and turn $\Bbb C\cong \Bbb R^2 \mapsto \Bbb C^2$ and then it separates into the two complex $\Bbb C$-irreps $e^{im\theta}$ and $e^{-im\theta}$?
 
Yeah, when you complexify my "real m-representation" above you get the complex m- and -m-irreps
But it is true that, as real representations, the complex m-representation and the real m-representation are isomorphic
 
it's just complex numbers for crying out loud
 
1:12 PM
I'm not entirely sure we're doing anything to clear up the issue. In fact, I've lost a bit of sight how this discussion is supposed to justify your rewriting of the multipole moments in that complex form...
 
@ACuriousMind no, it's helped
I can see the relationships now
=)
 
Alright, as long as you know how this helped, I'm happy ;)
 
In other news, though
what on Earth is this black magic?
the guys at giphy are geniuses
 
@ACuriousMind I did something wrong because I got a band ending
 
1:17 PM
band endings are the worst
 
@EmilioPisanty I think a .gif ending in an address does not in any way prevent the website from serving you more than just a .gif (in this case, you get a side dish of JavaScript)
 
@AccidentalFourierTransform ¯\ _(ツ)_/¯
random naming conventions
@ACuriousMind no, you get a full serving of html
 
Yeah, .gif doesn't forbid that. The interesting thing is that it still seems to serve the "pure" gif to the bot that embeds images here in chat...
 
owls are chouette
 
Jim
@SirCumference I dealt with inflation primarily. Mostly how different perturbations in the initial conditions evolved through it. And if you want to do early universe stuff, you really don't need much more math than what is needed for GR. Some would help. Do a course in QFT and GR and you'll pretty much have the math you need. Possibly EFT as well. But for the most part, the math in GR covers the math you'd use in early-universe cosmology
 
1:20 PM
@ACuriousMind yeah, that's the really remarkable bit
 
@0celo7 I don't buy into the assumption that it's a "bad" ending. I think the game is pretty good about presenting the consequences of your choices without making a clear value judgement of whether they were good or bad, and I'm not sure why you think Ciri becoming the Empress is bad.
 
@ACuriousMind not just on the bot. if you just make a local html file and embed that gif as an image, it will just load the image
it can't just be some user-agent dark magic
 
So, what do we do with a question that would be on-topic here, but is already answered over at chemistry?
 
@ACuriousMind I think it's a pretty shit thing for the game to do
Going to the emperor was a quest objective, how was I supposed to know that it was optional
 
It was clear enough to me that I didn't do it in my first playthough because I hated him :P (I don't remember, it was probably more a "let's see how long I can go without visiting him" than outright realizing it's a choice, but still)
 
1:30 PM
@ACuriousMind why did you hate him?
I feel like not playing 1 and 2 made me miss things
 
@0celo7 He wanted Ciri, but no so that she could live her life but to become what he wanted. Also he made Geralt shave and dress up. It seemed pretty natural for my understanding of Geralt to dislike his arrogance and expectation that everyone does as he tells them.
 
@ACuriousMind I got the feeling that it was his servant who made Gerald dress
Because you visit him a couple times and never have to do that again
 
@0celo7 Only because the emperor would have punished him otherwise - if you don't do the correct bow, you can hear him promising punishment to the chamberlain for failing to instruct you when you leave.
 
@ACuriousMind well how am I supposed to know that, I did the correct bow!
In any case, I thought it decent to bring him his daughter for a chat
Her betraying me was a surprise
Also I tried to pull a Mass Effect and pursue both romances, which didn't work
 
@0celo7 Ah, that's already an interesting choice: Whether you think of Ciri as his or as Geralt's daughter
@0celo7 It leads to a funny scene, though
 
1:42 PM
@ACuriousMind Ah, well it's not clear to me why she was ever in Geralt's care.
@ACuriousMind Do you get the feeling that the game runs much more smoothly in Toussaint?
my fps counter is always at 59.9/60.0 but in Toussaint it just seems better
 
@0celo7 That's the realm of the books' story - Witchers sometimes invoke the "law of surprise" as reward for their services, where the first unexpected thing one encounters at one's home is to be offered as reward, which usually means a child. That's how Witchers acquire at least some of their trainees. Ciri was such a child (and Emhyr was undercover in the North when he begat her)
@0celo7 Not really, but Toussaint does look gorgeous
 
Sid
oo, gravatar change by ACuriousMind
 
I do it every few months, nothing out of the ordinary :P
 
ACM likes being a gril
I would think Legion to be more fitting, but oh well
 
I was Legion already
 
1:55 PM
@ACuriousMind do you use an fps counter?
I can't get the steam one to work, and the one I'm using rn gives decimals
that's too stressful
 
No, why would I? I'm interested in the game looking fine to me, not the fps value
The only sort of numerical diagnostic I consider relevant is ping and packet loss when online gaming
 
you gotta know the fps
@ACuriousMind for some reason I can't get the steam overlay in any game
I think that's the issue
 
2:31 PM
@ACuriousMind first a testicles quest, now a bureaucracy quest?
Strange DLC
 
A testicles quest? Sounds like a load of bollocks to me.
 
Heyooooooooooo
 
2:54 PM
[Chemistry] Today's calculations involving borohydride. It predict there is some roaming stuff going on.

O well, these are all gas phase calculations, thus it is not surprising. However, roaming for such a heavy metal? Guess when I get to the wet lab part, I am going to check that in detail on whether nature really allow that...
 
00:00 - 15:0015:00 - 00:00

« first day (2443 days earlier)      last day (2493 days later) »