The h Bar

user223506

10:00

the plot thickens...

Pissed off layman

:-)

Kenshin

I hope ur main gets reopened if it was really banned for what u said

Pissed off layman

thnx

Kenshin

10:19

hello @JohnRennie

user223506

hello @JohnRennie

Pissed off layman

hello @JohnRennie

Kenshin

hello @JohnRennie

John Rennie

Morning all

Pissed off layman

Top of the morning to you :-)

user228700

10:26

@Kenshin: Yello! :-)

Kenshin

halo @Kaumudi.H.

user228700

@JohnRennie :-) True.

user228700

@Secret I hate to be a prick but you mean "Ilvermony" :-)

Pissed off layman

yup, as they say "only the good die young."

user228700

@Secret Ey, Hermione's patronus was an otter as well!

Kenshin

10:29

did you see the film too John?

@Pissedofflayman are you Doraemon?

Pissed off layman

who?

Kenshin

S007

/Doraemon

Pissed off layman

nope

Kenshin

ok

user223506

how are you @JohnRennie?

user228700

10:30

@Kenshin: Dude, we got him banned, why the heck would he tell us if it was him?

Kenshin

@Kaumudi.H I dunno cos he's sillly

Pissed off layman

You did what?

Kenshin

We didn't really

Pissed off layman

:-/

user228700

Well, he got himself banned by creating a sock puppet account but it was our conversation that brought this to light.

Kenshin

10:32

I had to delete the above

because i'm not allowed to speculate on why someone may have bveen banned

Pissed off layman

banning means nothing when you can open a sock puppet

Kenshin

3

A: Let's design and get some Physics Stack Exchange swag

user223506

the plot thickens almost to supercritical phase

Kenshin

@Pissedofflayman they can ban the sock puppet

Pissed off layman

Open another

Kenshin

10:34

do you have experience with this kind of thing?

Pissed off layman

perhaps

Kenshin

lol

Pissed off layman

:D

user228700

Gosh, I wish we could stop talking about banned accounts.

Pissed off layman

Done.

user228700

10:34

Anyhoo, @Kenshin: How're the holidays going?

Kenshin

good

i'm back from my trip

user228700

Where did you go, if u don't mind me asking?

Kenshin

sorry too private

user228700

Okay, I'm sorry.

Kenshin

np

is that u Kaumu?

wearing the hat

or celebrity?\

Pissed off layman

10:36

or both

:P

Kenshin

yes

lol

user228700

If you mean the girl in my avatar then yep, that's me! :-)

Kenshin

oh yeah cool

user228700

@Kenshin Lol, I'm flattered :-P

Kenshin

good pic

@Kaumudi.H np

user228700

10:37

Thanks. I don't have too many :-P

Pissed off layman

You should.

Kenshin

@Pissedofflayman what do you mean?

@Kaumudi.H maybe u have more pics than John though

he only has 1 pic

Pissed off layman

She's photogenic

user228700

@Kenshin I certainly do! x'D

user228700

@Pissedofflayman No, lol x'D

Kenshin

10:38

@Pissedofflayman seems to be but could be a lucky shot

Secret

@Kaumudi.H Don't know what it symbolise however. Hermonie's patronus is an otter is because back in those time JK Rowling identifies wth her and she like otters. JK Riowling's patronus have recently changed into a heron looking bird

user228700

@Secret Yes, that is true. All of it :-)

user228700

@Kenshin Yep, that's what it is :-P

Pissed off layman

Modest too

Kenshin

@Kaumudi.H did you check out my t-shirt suggestion?

Secret

10:41

Meanwhile in all unofficial sites with patronus test, mine end up either as a swan or a peacock

user228700

@Kenshin Kinda. Didn't check it out properly. Is that a shirt that you designed?

Kenshin

no not this one

it is apparantly one that was given away many years ago to top users on the site

I like the simplicity of it, i'm not a fan of heather's one (but still appreciate the proposal heather :D)

user228700

Oh, I see...

user228700

It looks cool :-) +1

Kenshin

yay

Secret

10:43

As for my wand in the official website, its description matches my personality quite perfectly

Sycamore wood which like change and novelty
Unicorn hair for faithfulness and consistency
and on top of that, extremely squishy flexibility for my crazy and wild thinking

user228700

@Secret Wow, where did u find these?

Secret

In the pottermore website, there's a tab that ask you to check your wand, it give you a bunch of questions and after answerin them assign you a wand a house etc.

My house is indeed what I predict: Ravenclaw

Looks like I knew myself well enough

user228700

@Secret Yes, of course (Clearly, you haven't read the transcript for this morning) but how did you find all that wand stuff? What it means, I mean.

Secret

after you have finishes, scroll down and it describes your wand in detail

user228700

Oh, wow, I missed that. Brb :-P

user228700

10:46

Oh, crap, I have to take the test again. Oh, screw this >.<

Kenshin

laterz all

user228700

Bye :-)

Secret

Actually quite the opposite, I only end up in the pottermore website because I have read the transcript, but I probably misunderstood your question initially

Before then I don't know there exists a website called pottermore, I only heard of the term in UK wen visiting the warner bros studio

user228700

@JohnR: Quick question. Do you buy all the books that you read?

user228700

@Secret Ah, I see.

John Rennie

10:56

@Kaumudi.H that's ... a possibly incriminating question :-)

user228700

Ah. Does nobody use libraries anymore?! (To read fiction, not to borrow expensive textbooks!)

John Rennie

I rarely borrow books from the library these days.

The trouble is that even ina middle sized city like Chester the library can offer only a limited selection of books.

user228700

I assume that you have other bookshelves for your Sci-Fi collection, yes? You showed us a picture of what u said was ur bookshelf and it didn't look like it could hold a thousand [ :-) ] books...

user228700

@JohnRennie Ah, I see...Dyou own a kindle?

John Rennie

I read mostly e-books. I use an Android tablet not a Kindle.

user228700

10:59

Oh, I see! And you prefer kindle to physical copies because..?

John Rennie

I read several books a week, and if I read physical books the house would be full of books.

Whereas with e-books I just keep them on my server.

user228700

@JohnRennie I'm surprised it took me so long to ask about that :-P

John Rennie

I thought we've talked about books before?

user228700

Well, we kinda have but I've never asked about how you read them.

John Rennie

My recollection is that you'd like to read more but your schedule doesn't exactly make that easy. At least until June.

user228700

11:02

Yes, that is correct. Like I said, I've read only about...2 books this whole year.

John Rennie

For me reading has always been an escape from the real world. I read SF because their worlds are so wonderful.

user228700

I read Charlotte's Web when my sisters borrowed it from the library (and I hadn't found a chance to read it till now!) and then I think I read a book and a half by Rainbow Rowell...I finished Fangirl and bits of Eleanor and Park.

John Rennie

The real world is, well, it's not a bad place but it's no paradise either

user228700

@JohnRennie Yes, this is true in my case as well, but I haven't read that much Sci-Fi yet.

user228700

Say, how many books dyou think you've read so far?

John Rennie

11:06

In my whole life? It must be getting on for ten thousand.

user228700

TEN THOUSAND?! Geez, that is a lot. Have u always read this frequently?

John Rennie

I've slowed down these days, but as a youngster I would read five or six books a week - every week.

I average two to three books a week these days.

user228700

What? That's crazy. And how many of these are SF?

AccidentalFourierTransform

@JohnRennie what is your fav book?

user228700

@AccidentalFourierTransform I'm not sure if this a fair question to ask to a person who has read almost TEN THOUSAND books so far :-)

John Rennie

11:08

@Kaumudi.H Almost all are SF or Fantasy. I don't want to read about real life. I get to live real life every day and when I read I want something different.

user228700

@JohnRennie Right, but are all of them Science fiction? Nothing... just fiction?

John Rennie

@AccidentalFourierTransform I don't have a favourite book because I rarely go back to books, and anyway my tastes have changed over the years.

My favourite book of the last few years is Among Others by Jo Walton.

amazon.co.uk/dp/B008GQHO86

user228700

Nice! :-) If I were to ask you to list perhaps, your top 10, would u able to do that..?

John Rennie

@Kaumudi.H I read popular science and popular maths books, but as I've learned more and more about science I find the pop sci books are too basic.

user228700

@JohnRennie Forget science!

user228700

11:11

Nothing else..?

John Rennie

Nope, nothing else.

As I said above, I find books that are too much like real life boring.

user228700

Wow, that's...wow, I see.

user228700

Ooh, since you've read so many books, have u read the series "Life as we knew it"?

Secret

Meanwhile I have dreamt of myself using various wands throughout these 10+ years of exposure to harry potter movies
In Dream 7/2/2012 (Casted a patronus charm towards sister) using some unspecified wooden wand
In Dream 9/12/2011 (Where I duel with voldermort, including a strange golden sphere spell that has a simialr effect to the Cruciatus Curse) using a golden wand made of metal
In Dream 15/7/2013 (Casted 3 so called golden orb spells with the same wand in Dream 9/12/2011)
In Dream 8/10/2016 (Casted a few other spells using an invisible wand)

In reality, In the harry potter universe, however only slughorn's wand has metal components (at the handle), all known wands are wood based

I guess one possible explanation might be reflecting my fascination of metal complex chemistry

John Rennie

@Kaumudi.H no. The Young Adult genre didn't exist when I was a young adult and I'm far too old for it now. Though some would argue that young adult and science fiction are synonymous :-)

Secret

11:19

Assume we go a bit crazy and assume every fiction, reality and dream all belong to the same continnuity, it is actually logical to say that the wand in Dream 7/2/2012 might be the sycamore wand that was assigned to me in the pottermore website

user228700

@JohnRennie Oh, wow, I see. Hmm, really? Who argues that?

John Rennie

@Kaumudi.H I suppose I do. I love reading SF but most of it is woefully immature. And that's fine. I don't read SF to improve my brain. I answer questions here to do that :-)

user228700

@JohnRennie But they aren't exactly the same! There are a LOT of books out there that are young adult but have nothing to do with science.

John Rennie

Ah, I see what you mean. Yes, it would be more accurate to say that the intersection of SF with young adult literature is, erm, almost total :-)

If I knew enough set theory I could write that as a mathematical statement ...

user228700

Almost total?!

user228700

11:29

No way!

user228700

I'm talking about coming of age books!

user228700

Catcher In The Rye, Lord of The Flies, um, what else are some oldies? I know only recent ones...

John Rennie

I mean SF is almost a subset of young adult. That is most SF is young adult but young adult includes many other genres as well.

So I think we are saying the same thing.

user228700

Oh, right, yes :-) If I knew how to write in LaTeX, I would write that as a mathematical statement...

John Rennie

The main thing is I get a lot of pleasure from reading SF and fantasy.

user228700

11:33

:-) I see. Would u be able to name your top 10 series of all time?

John Rennie

Almost as much pleasure as I get from eating. I wonder what if I combined the two activities ... :-)

user228700

How would u combine the two..? You could eat while you read but that you already do, I assume...

John Rennie

@Kaumudi.H that's really hard. For example as a lad I loved the Lensmen series by E. E. Doc Smith. But these days it seems very childish.

user228700

Oh, right, because you've read all these books over many many years...

Secret

Given any set $S$, and a measure $\mu : S\rightarrow [0,1]$
$$\{\textrm{SF}\}\subseteq \{\textrm{young adult literature}\}, \mu((\{\textrm{SF}\}\cap \{\textrm{young adult literature}\})^C)=0$$

user228700

11:35

What's the $\mu$ thing..?

John Rennie

My favourite recent series is the Ancillary Justice series by Ann Leckie. I think it's a really interesting new idea and I strongly recommend it.

user228700

Will look it up, thanks :-) Speaking of Sci-Fi, have you watched one of those movies you gave me? Eternal Sunshine of The Spotless Mind?

Secret

A measure gives the size of a set relative to another under some kind of standard

It is a generalisation of distance

user228700

@Secret I don't fully understand that, but okay...

John Rennie

@Kaumudi.H No, I got that for my niece. I've watched the Star Wars trilogy, but when they were originally released.

user228700

11:38

@JohnRennie Oh, I see. How old is ur niece? (The movie's a bit too...raw and painful and real)

John Rennie

15

user228700

I see.

John Rennie

The first film, episode IV now, is quite brutal in many ways. But then it wasn't made as a childrens film.

But my niece has watched all the Mummy films, which feature people being eaten alive by scarab beetles (!!) and she seems fine with them. Although she has never watched the original Alien film, which I think is the scariest thing I've ever seen.

user228700

No, I mean, okay, that kind of stuff if violent, right? ESoTPM is emotionally kinda painful is what I meant...

John Rennie

Ah. I've never seen the Eternal Sunshine film so I wouldn't know. I don't think my niece has seen it either.

user228700

11:48

Oh, but u said that she wanted it so that's why I asked how old she is. I don't think I still fully appreciate that excellent film...

John Rennie

Ah, good point. Maybe someone else asked me for a copy of the film ...

user228700

Okay :-)

Secret

12:09

in Mathematics, 2 mins ago, by s.harp

the set of books is finite so you have a canonical measure: the counting measure

in Mathematics, 2 mins ago, by s.harp

since there are SF books that are not young adult you have that the measure of the intersection with the complement of YA is non-zero

$$\{\textrm{SF}\} \cap \{\textrm{YA}\}^C > 0$$

Not really spamming, just my habit of able to make a joke serious and then turn it into some formal discussion

Pissed off layman

ok

Secret

Well... I had a habit of short circuiting jokes, it might be a reflection of a twisted type of sadism or a gate crasher or whatever

Pissed off layman

To each their own.

:-)

ACuriousMind

13:08

@Secret That doesn't make any sense as a joke nor as formal discussion because ">" is not defined on sets.

Slereah

Yeah you might want to add a cardinality somewhere

Secret

Right, I forgot the cardinality

Kenshin

13:32

@Secret I undersatnd the joke

perhaps it could be not equal to the empty set?

anyone here played nerve?

heather

14:09

hello everyone

AccidentalFourierTransform

hi

Secret

what does your cat look like before it is accidentally fourier transformed?

Kenshin

hi @heather

@Secret what?

heather

That cat has some serious periodic components

Kenshin

oh lol

heather

14:22

see Accidental Fourier Transform's avatar

Kenshin

it matches

heather

exactly

Kenshin

and it's a nyan cat

AccidentalFourierTransform

oh hey that's me :-D

yep, I'm nyan cat now. Is this hat cool?

heather

14:38

Understanding e to the pi i

►

2

^best video ever

except for that guy's videos on linear algebra

DanielSank

>:(

Opening sentence: "...one of the most famous equations in math, but it's also one of the most confusing"

~sigh~

user223506

@DanielSank hi!

Kenshin

wtf how is it confusing

DanielSank

Look, explaining things clearly is good, but please, please, please don't tell your students that something is confusing!

@Doc Hello.

heather

perhaps what was meant was "it's also one of the most confusingly taught"

DanielSank

14:48

@Kenshin If you haven't seen complex numbers or $e$ before I guess it's pretty confusing!

@heather Better statement!

I don't like it when teachers say "this is confusing". It's like... ok, uh, thanks?

Kenshin

@DanielSank why would you need to learn the relationship if you haven't seen $e$ or complex numbers?

heather

@Kenshin my first question when I saw it: what the heck does it mean to have something to an imaginary exponent?

DanielSank

@Kenshin ::shrugs::

@heather Right, should start there!!!

heather

@Kenshin i don't know, one's been told it's one of the most fabulously awesome equations ever?

DanielSank

I just realized I have a pretty messed up way of thinking about this.

heather

14:50

@DanielSank i thought the video made quite a bit of sense.

i don't think i could explain it to someone but it got me in the right direction.

DanielSank

@heather It does! It's great. I just wanted to point out that opening sentence. That's all.

Kenshin

@heather, yes but you need to know the fundementals

DanielSank

@heather Excellent!

heather

@Kenshin, sure, but I thought it was cool, and I was jumping out of line for a moment. =)

Kenshin

@heather the equation itself isn't fabulous or remarkable or important

heather

14:51

@Kenshin, tell that to the guy who came up with it =P

Kenshin

@heather the equation is a trivial example of a more fundemental topic

and this trivial example is made famous just because it includes all of those constants

DanielSank

@Kenshin Oh I dunno, it only involves the five most interesting numbers in existence...

$$e^{i \pi} + 1 = 0$$

Kenshin

@DanielSank yes it is a curiosity only

in practice one would use the concepts that developed this equation, to make one's own relevant equation

and one would rarely ever use this particular equation

DanielSank

@heather don't get me wrong, the video is quite excellent. Focusing on numbers as "actions" is absolutely excellent and is exactly how I think about it.

When I said above that I have a messed up way of thinking about that equation, I had in mind that I think $e$ by its action of exponentiation. I didn't realize yet that the video takes the same approach.

Kenshin

@heather this is what is really important:
https://en.wikipedia.org/wiki/Euler's_formula

Euler's formula

Euler's formula, named after Leonhard Euler, is a mathematical formula in complex analysis that establishes the fundamental relationship between the trigonometric functions and the complex exponential function. Euler's formula states that, for any real number x: e i x = cos ⁡ x + i sin ⁡ x {\displaystyle e^{ix}=\cos x+i\sin x} where e is the base of the natural logarithm, i is the imaginary unit, and cos and sin are...

heather

14:53

148

A: What was the first bit of mathematics that made you realize that math is beautiful? (For children's book)

The first "math thing" that just blew my mind was the identity $$ e^{i\pi} = -1 $$ Namely the fact that the two independently discovered transcendent numbers and imaginary one so simply and elegantly bound. In the marginally rearranged form $$ e^{iπ}+1=0 $$ it uses absolutely nothing but nine es...

DanielSank

That's cool.

heather

@Kenshin I'm 99.9999% sure that this is derived from that!

DanielSank

@heather For a children's book? Uh oh...

Kenshin

@heather exactly

DanielSank

Hey guys wanna see something neat?

Kenshin

14:54

@heather my point is, look at the fundemental formula (Euler's formula) which is better than the trivial derivation

heather

@DanielSank sure

DanielSank

@heather, can you write a matrix that corresponds to a rotation by angle $\theta$ in 2D?

heather

@Kenshin ::groans::

@DanielSank hmm, maybe, give me a moment

AccidentalFourierTransform

@DanielSank $\mathrm e^{-\frac{i}{2}\boldsymbol\theta\cdot\boldsymbol\sigma}$.

(maybe?)

Kenshin

@DanielSank wikipedia has already done it?

DanielSank

14:55

^ Shhh!

@AccidentalFourierTransform What's $\sigma$?

heather

oh, wait, I'm thinking about this wrong, this is rather easy

AccidentalFourierTransform

A Pauli matrix

DanielSank

@heather This is a really excellent video.

@heather Yes it is.

heather

$\begin{bmatrix}0&1\\1&0\end{bmatrix}$

would be one example, right?

Kenshin

@heather can you make the matrix a function of the rotation angle $\theta$?

DanielSank

14:58

@heather Yes, how much rotation is that?

Actually, that's not quite a rotation...

That's a reflection about the line $x=y$.

heather

let me retry =)

AccidentalFourierTransform

here, have this: $-$

DanielSank

Hey, no cheating.

Kenshin

lol

Transcript for