Mathematics - 2012-11-02 (page 7 of 7)

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11:00 PM

yes topology is very interesting

user19161

Wow it's 7 am already.

I think continuity, homeomorphisms, connectedness and compactness are important to know for other areas of mathematics. I am sure topology is fun to many analysts and set theorists in and of itself. (I think algebraic topology would be fun to learn at some point.)

@JasperLoy it's 3:00 here

user19161

@Nimza Are you partying there?

@JasperLoy Therefore, we are pretty close to half way across the world from one another.

11:01 PM

just trying to think of something cool from topology

00:03 here

The only topology I would like to study is algebraic; the other stuff never interested me to study (maybe I just don't grasp the key concepts).

user19161

@anon You seem more and more mysterious to me now...

@JasperLoy no, I'm trying to go to bed for a while

I hate algebraic topology, lol

11:03 PM

I like sections, but there is so much "basic stuff" you have to know first - it's exhausting

hm, is it obvious to what equal limit $\frac{(x+h)^{n\alpha}-x^{n\alpha}}{h^{\alpha}}$ when $h \to +0$? $0 < \alpha < 1$

I've got to learn Tychonoffs theorem for my classes

so much language and objects you never know you grasp in enough detail

am I the only one who can't read LaTeX in this chat?

@NickKidman See LaTeX support for chat on the sidepanel.

user19161

@NickKidman I am quite bad at it too.

11:05 PM

that reminds me, a lot of topology stuff ends up using axiom of choice

@Nimza it is equal to $\Delta (x^{n\alpha})/\Delta x \times h^{n\alpha-1}$ so...

@anon: where exactly?

en.wikipedia.org/wiki/Ultrafilter

these are wild

I didn't know this was classed as topology

@JasperLoy: bad at it? I've never said anything like that.

@anon hm, i can't understand your notations :(

11:06 PM

@NickKidman let me be the first to tell you about the hidden ctrl+f feature in many software programs, like browsers and document readers

user19161

@NickKidman Oh you did not install the chatjax?

@JasperLoy: I think I only say that I'm bad at something if it's to my advantage

@jdoe Compare definition of filter with definition of a topology.

my favorite thing from topology is the hausdorff dimension

user19161

@anon I know about it too.

11:07 PM

@Nimza I mean $$\frac{(x+h)^{n\alpha}-x^{n\alpha}}{h^{n\alpha}}\cdot h^{(n-1)\alpha} $$

although it is extremely hard to actually use it

but I think that is a very important concept

ah, fractals

not really important, just interesting

tldr

@anon heh! that's from fractal calculus! (local fractional calculus)

user19161

anon is so mysterious I am going to think of anon for the rest of my life...

11:08 PM

@NickKidman surely "drag this and click it" isn't tldr

what the heck am I doing

drag what?

user19161

@anon You must have been distracted by my line there. =)

$$\frac{(x+h)^{n\alpha}-x^{n\alpha}}{h}\cdot h^{1-\alpha}.$$ there we go

I'm just putting off going to bed

@NickKidman have you ever dragged links before? do you know what a bookmarks bar is?

11:11 PM

in my firefox browser

@anon aha, thanks :)

en.wikipedia.org/wiki/Topologist%27s_sine_curve

that was in my calculus book a lot

counter-example

I still think it's incredibly sad/pathetic that we don't have something like this for chat: userscripts.org/scripts/show/108770

so this is $=(f'(x)+O(h))h^{1-\alpha}$ where $f(x)=x^{n\alpha}$

@jdoe: en.wikipedia.org/wiki/Counterexamples_in_Topology

11:12 PM

@kahen what's wrong with our chatjax?

manually having to click a bookmark to get mathjax rendering is too damn primitive

@NickKidman, yeah that book is way over my head maybe in a few years I could read it..

so where is this bookmark place

one of these days I will make a video tutorial for newbies

user19161

@anon Will we get to hear your voice?

11:14 PM

no

hey the p-adic page got cooler en.wikipedia.org/wiki/P-adic#Analytic_approach

@JasperLoy: Are you flirting?

user19161

@anon So when will you reveal your identity?

wow someone has put a lot of work into it

I've discovered anons identity..

user19161

@NickKidman Depends on the definition...

11:15 PM

he's the 3-adic numbers

user image

@JasperLoy: that's a tautology

how cute. someone who actually has their bookmarks bar visible

(that's a douchbag sentence and I would advice myself to read more of the late wittgenstein)

user19161

@NickKidman If you know what I am thinking now you will know what I mean. And this is also a tautology.

11:16 PM

I use chrome, where my bk bar is filled to the brim with textless icons and folders

good night! 3:16 is not a joke :\

firefox I use for other purposes and it is more or less out of the box

user19161

@anon Chrome doesn't load chat well for me, so back to firefox.

@JasperLoy: what? I have no clue what you think right now

you're a blue square, what do I know about you?

@jdoe look up pontryagin duality on wikipedia and observe that 2=3 is false

user19161

11:17 PM

@NickKidman It's my secret.

2 and 3 are close enough

just take N large

I was doing something important and no longer remember what it was

thanks guys

user19161

@NickKidman Exactly, my name might not be real either...

@anon: showing me how to get rid of the $'s

>spending money

not like your name is in acknowledgements in well-known notes or anything

11:19 PM

>implying my name is real

in fact, I don't like people using their real name on the internet

>implying I was talking to you
>implying greentext
>implying this is 4chan
>implying

disgusts me

@anon, can you recommend me to learn Pontryagin duality

>implying implications

@jdoe Yes, I recommend PD to you.

11:19 PM

@jdoe: I do

what should I read?

abstract harmonic analysis

any applications in number theory

oh man that sounds difficult

extremely useful in number theory

user19161

@anon Where do you learn that?

11:20 PM

books I guess

> Walter Rudin, Fourier Analysis on Groups, 1962

is this readable?

as an introduction

@NickKidman when you click the "render mathjax" icon in your bk bar while you are in the chat tab, all latex inside of $'s will be rendered for you

user19161

The first thing I remember about anon is that I associate anon with abstract harmonic analysis.

what do you use abstract harmonic analysis for?

11:22 PM

@JasperLoy: funny, I think of fapping

user19161

@jdoe You use it for harmony.

you're def from the chans then

user19161

Harmonic analysis is applied everywhere in the world to bring harmony.

I also think of V for Vendetta

user19161

You know what @anon? I keep saying all these things which make people upset, like today. I really don't belong to this world.

11:24 PM

imgur.com/EfdfO - look ma, no bookmarks bar. I can show them by pressing alt+b anyway. Very nice to not waste vertical screen real estate on something i hardly ever use

It is absolutely imperative I figure out how to turn off the predictive text on my cell phone.

the toolbar doesn't accept any droppings

then you're doing it wrong

@anon, can you do it to p-adic numbers for arbitrary prime ideal p of a number field? (not just Q_p)

you can also right-click to add it to the bk bar

@jdoe yes

it needn't even be prime

11:25 PM

do you know any applications of that?

I even modified firefox to make that ridiculously "loud" orange "Firefox" button blue instead

user19161

@kahen Which button?

look at anon's earlier screenshot in the upper left corner

@jdoe you can define the laurent series ring R[[x]] as the (x)-adic version of R[x] (look up I-adic topology and inverse limits)

I know about I-adic topology and inverse limit

11:26 PM

huge "Firefox" button in an orange colour that just screams for your attention. I find it unbelievably distracting

user19161

@kahen What do you change it to?

transparent. so it shows up as blue here

user19161

You go to that extent?

userchrome.css is a wonderful tool if you know how to use it

user19161

If I were on Windows 7, I would use IE.

user19161

11:28 PM

IE is improving greatly.

en.wikipedia.org/wiki/Pr%C3%BCfer_group

so this is what's important

Not in a million years. No Noscript. No Greasemonkey. No ABP.

user image

the bar above is empty, just a white bar

below is this bookmarks toolbar folder, but it doesn't do a thing

user19161

@NickKidman I see anon in there!

is that Konqueror?

user19161

11:31 PM

By the way, my password is still ************.

I thought you said you were using ff so I used ff in my ss. Did you try making the bk bar option on "show"?

oh, you are joking, I see

derp

user19161

What is the joke?

it was a joke, but I really still have mathjax

I am having too much fun here to go to bed :(

user19161

I am bad at jokes, they laugh at me in ELU room... =)

11:35 PM

what is ELU?

user19161

Eng SE.

if you let water in a class stand for some ours it tastes terrible

I've done it for days in my room

tastes fine

a little spidery but no harm

maybe the water is better where you are

I moved from godlike water city to okay water city

user19161

@NickKidman Did you make some terrible typos there?

user19161

11:39 PM

Hmm, I think I will change my blue colour to something else.

How about textured brown?

typos?

Hello good people! I have a quick question just to make sure [1,inf) is a closed subset isnt it?

of the reals? yes

yes

:).thank you

11:41 PM

in the standard topology

(hurr durr)

closed in C or any R^n w/ standard top innit

closed in the lower limit topology too

got a new glass of water

(a new class of water, hehe)

also, müsli and nuts

Thanks to all for replies, somehow I didnt think about other spaces that contain it,but for R it is closed beacuse (-inf,1 ) is open right?

@Pilot, that's a good way to prove it

11:44 PM

Thank you!

that would be the proof directly from the definition of what a closed set is

(-inf,1) is open since it's an (infinite) union of open sets

formally, how do you write \infty as a bound in an interval anyway?

user19161

@anon That's a bit too far right? He's only talking about R from the way he wrote it.

don't know what the definition of an interval is, i.e. probably in terms of unions of other sets

11:45 PM

$[a,\infty) = \{x \in O : a \leq x\}$ where $(O,\leq)$ is some totally ordered set?

(-inf stands for an absence of a lower bound and +inf) stands for an absence of an upper bound

user19161

@kahen Also depends on how you define closed.

okay, yes, sounds good

where can you measure your body fat?

user19161

I wonder how many hours the colour change will take to be observed.

of your ava?

user19161

11:47 PM

@NickKidman Don't know what an interval is, really?

chances are, if it will not be observed immediatenly, it will never. why would someone observe it in the aftermath, long after your other blue one is gone

dns propogation delays

@JasperLoy: Didn't think of the reals as ordered for a moment

user19161

@seaturtles Are you trying to confuse us all now with that new user?

@JasperLoy: Had to think of general boundaries yesterday

user19161

11:49 PM

@NickKidman Tell you what, just forget about physics and do math instead, it's easier that way.

@JasperLoy: What made you think of that now?

ah, black. I see it in one browser but not the other.

user19161

@seaturtles Yes, this black represents the darkness of my thoughts now...

I don't intend "to do" physics OR math. I plan to have an impact on the world - whatever route that might entail.

user19161

I don't plan to impact the world, I gave that up long ago.

11:52 PM

I'd argue that most theoretical physicists nowadays do math. They get on a route following their guide as PhD students and then solve some problem. Actually doing physical considerations instead of mathematical deduction is extremely difficult

giving up is deciding to lose, isn't it

user19161

@anon Are your weekend plans the same as last week's?

work, sleep, eat.

or 2/3 at least

user19161

OK, mine are the same too: X, Y and Z.

@JasperLoy: youtube.com/watch?v=0pbF4qDSKCg

@anon work work work, eat, work, sleep,

and you surely missed "coffee" like ten times

user19161

11:58 PM

@peter I am now black.

I don't drink coffee

user19161

@anon Do you do tea?

@anon What do you drink?

I should learn from the master.

I do mountain dew on my night shifts to stay awake. @Jas yes, flavored and sweetend

user19161

@PeterTamaroff Yes anon is the master, I am only the banana.

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