Mathematics - 2015-03-18 (page 2 of 4)

David Wheeler

05:08

Well, it turns out such things are connected to finding the eigenvalues/eigenvectors of a linear transformation (matrix)

Kaj Hansen

Posted on main for the first time in months lol

Mike Miller

saw that

infinitesimal

05:41

Hi pal @ParthKohli

Parth Kohli

@infinitesimal Hello.

infinitesimal

How are you?

Parth Kohli

I've been excellent. A change that I've noticed in myself is that I'm now able to "see through" problems in fields that I haven't formally studied.

David Wheeler

06:28

Really? Give an example.

infinitesimal

06:49

I think they call that "mathematical maturity."

11

Q: mathematical maturity

So, I finished my undergrad with a degree in applied mathematics, but when reading some graduate level texts and/or papers, I often find myself struggling. I eventually get there, but I often feel like I lack the intuition necessary to be able to come up with concepts on my own. I feel like I'm...

I'm glad to hear that pal @ParthKohli :-)

David Wheeler

07:27

Sometimes, I think mathematics is like being a mechanic. When you first start, all you do is turn bolts. Even a simple repair, is a long sequence of bolt-turning. Later, you're able to "compile" certain sequences of bolt turning, like: "take off the radiator, to get to the water pump". An expert can compile at a very high level: "rebuild an engine".

David Wheeler

07:43

Grr...I'm really mad about what I'm reading about Ferguson

Gato

07:55

@DanielFischer Hi, I would like to prove that $\binom{n}{k}=\frac{1}{2i\pi}\int_{C}\frac{(1+z)^{n}}{z^{k+1}}dz$. I cannot get that expression if I write the integral as $
\int_{0}^{2\pi}\frac{(1+re^{it})^n}{r^{k+1}e^{it(k+1)}}rie^{it}dt
$ where $r$ is the radius of the circle $C$.

Now using the binomial theorem I can write $(1+re^{it})^n=\sum_{k=0}^n \binom{n}{k}r^ke^{ikt}$ right ?

I think I misunderstand something because $\binom{n}{k}$ is the coefficient of $z^k$.

infinitesimal

What's making you mad @DavidWheeler?

David Wheeler

08:34

Ferguson, MO has some problems with their police department.

Police routinely stop people there for no probable cause, and then, having done so, will write citations for such crimes as "Manner of Walking In Roadway", "Failure to Obey", "High Grass and Weeds". If people fail to appear, or miss a payment on their fines, arrest warrants are issued, often with no notice.

When arrested for this, often people have to post bond for release, and often this bond payment is not applied to their fines. People wind up racking multiple warrants as a matter of course.

The town officials acknowledge, in city e-mails, that the entire purpose of this is not to protect public safely, but to generate revenue for the town.

Daniel Fischer

@Gato Note that $dz = ire^{it}\,dt = iz\,dt$. That's why you divide by $z^{k+1}$.

A Beautiful Mind

08:53

I just got some meds from the doctor. Exactly what I predicted.

David Wheeler

SSRI?

A Beautiful Mind

Fluvoxamine which is an SSRI and clonezapam which is a benzodiazepine.

David Wheeler

Did you talk to your doc about dosage adjustments if necessary?

A Beautiful Mind

It's only the start. We can adjust later on.

David Wheeler

Lol, I know that. I just wondered if you asked.

A Beautiful Mind

08:59

No I didn't.

I have realised that without my father I think I would not get any mental problems.

Maybe I would have won the Fields medal by now, lol.

But now I am reduced to doing 1+1=2.

David Wheeler

Oh, you underestimate yourself. I bet you can also do 2+2.

A Beautiful Mind

If I can get well somehow I still might be able to solve Riemann.

David Wheeler

Perhaps. That ought to be something.

A Beautiful Mind

It is comforting that the doctor said 'Don't kill yourself, we can help you'.

'Don't help yourself, we can kill you', LOL.

David Wheeler

That's so morbid, Jasper. Funny, too.

A Beautiful Mind

09:09

You know, I feel less anxious after taking the clonezapam, maybe the placebo effect has set in, lol.

OK, but honestly, the anxiolytics do work, but I am not so sure about the antidepressants.

ADG

hey do you know about collatz conjecture.

David Wheeler

Try to keep a journal, if you can. It might help your doctor with dosing.

ADG

isn't the conjecture obvious?

A Beautiful Mind

Don't sound like a crank.

ADG

since you are forcing every number to 1?

David Wheeler

09:14

It's only obvious to me if $n = 2^k$

ADG

because it will end in positive numbers for sure.

and if it is not 1, you process it and process it until you get 1.

David Wheeler

How can you be sure you do not get a cycle that never reaches 1?

ADG

we can prove by contradiction that it cannot end in any other positive integer

if it ended for example on an odd/even number other than one we would be able to process it again,

like it can't end in 2 because we can turn that1

3 to 10 to 5 to 16 to 8 to 4 to 2 to 1

4 to 2 to 1

David Wheeler

Ok, but why does it HAVE to end?

ADG

and so on

ok you mean why don't we get entrapped in an eternal cycle?

A Beautiful Mind

09:18

Hey @infinitesimal.

David Wheeler

Indeed, that's the "devil in the details"

ADG

like we have reached "p" and we process and reach "q" after sometime which points again to p?

David Wheeler

The numbers might go up and down erratically.

ADG

ok so the conjecture is accidently designed in such a way that has no such cycles (to whichever gazillions of numbers it has been checked)?

and now about golbach conjecture too.

i wish to talk.

suppose we have some infinite collection of numbers.

one of those is prime numbers

one is the counting itself.

one are the even, one are the odd , etc.

lets make our base the positive integers

i mean to say the prime numbers are so relatively dense wrt the base that every number ($\ge 4$)can be represented as the sum of two such numbers.

but the main problem is prime numbers are kinda random.

David Wheeler

You could make a statistical argument, but that would not be a proof.

ADG

09:24

yup

i mean it could be proved if we categorize and study other such nnumbers which prime no.s are a dubset of. e.g. numbers which have exactly 3 divisors.

David Wheeler

On the other hand, if we knew ALL the zeros of the Riemann zeta function (in the critical strip), we could have something better to work with. But that is also a very difficult problem.

ADG

and finding about $\zeta(3)$ and which is related to primes maybe?

David Wheeler

Some problems are easy to state, but hard to solve.

ADG

i told my friends about such things and they often laugh and say "this is easy"

maybe we shouldn't judge a book by it's cover?

David Wheeler

Your friends are not professional mathematicians, I take it?

ADG

09:31

neither am I :D

David Wheeler

Hard problems can take centuries to solve, if it can even be shown they ARE solvable. What's worse, it is known that not every problem IS solvable, so we never know at the outset whether or not we've "found a bad one".

A Beautiful Mind

It is not known whether my mental problems are solvable.

I need to believe that something extraordinary is possible.

David Wheeler

@ABeautifulMind Ok, but are they able to be formulated in a first-order arithmetic?

A Beautiful Mind

@DavidWheeler Maybe third order.

David Wheeler

Sounds like you need a meta-doctor. :P

ADG

09:36

@ABeautifulMind you remind me of the chemistry chapter i recently mugged up on chemistry in everday life.

A Beautiful Mind

@ADG What is it about?

ADG

about drugs

antibiotics/antihistamines/antidepressants/antacids

about soaps and detergents

about antioxidants

and so on..

Committing to a challenge

@DavidWheeler What's a problem that can't be proven true or false?

Alec Teal

Morning

Okay WTF " Some problems are easy to state, but hard to solve. - 12m ago by David Wheeler ▼ " - who starred that? Was it an overzelous judge from the "Stating The Obvious award" panel?

David Wheeler

The Problem encoded via a Godel numbering system that says that "This Theorem is Unprovable"

A Beautiful Mind

09:41

I need a suggestion.

Committing to a challenge

@AlecTeal That's a little harsh :P

A Beautiful Mind

I deleted jasperloy at gmail dot com long ago so I cannot get it back. What shall I use for my new gmail account?

Alec Teal

Don't do it @ABeautifulMind no matter how convincing of an argument the voices make.

@ABeautifulMind [email protected]

A Beautiful Mind

@AlecTeal gmail does not distinguish with and without dots.

Alec Teal

It does.

Committing to a challenge

09:43

wut?

A Beautiful Mind

It does NOT.

Alec Teal

It does to.

A Beautiful Mind

I am 100 per cent sure Alec.

Alec Teal

It'd be really bad if it didn't.

David Wheeler

@AlecTeal Comments can be starred even if they're silly. Especially if they're silly, if past stars are any indication.

A Beautiful Mind

09:43

It is by design and for a good reason.

Committing to a challenge

WOW it doesn't

Alec Teal

@ABeautifulMind clearly you know best.

Committing to a challenge

I just checked

My girlfriends gmail has a dot, and it worked without

A Beautiful Mind

It also doesn't distinguish between capitals and small letters. So Abeau is the same as a.b.eaU

Alec Teal

No way

@Committingtoachallenge you're straight!?

Committing to a challenge

09:44

@ABeautifulMind Yeah I knew the caps one

@AlecTeal Yep legit

Alec Teal

:P

A Beautiful Mind

@alec are you gay?

Alec Teal

[redacted]

A Beautiful Mind

So you are bi?

Committing to a challenge

@AlecTeal Oh I thought you meant 'you're straight' as in 'truthfully?'

Alec Teal

09:45

I was like "No way @Committingtoachallenge you're straight?" rather than the dot thing.

David Wheeler

Darnit, Jasper, stahp hitting on the math dudez.

A Beautiful Mind

I am not gay but I like Justin Bieber a lot.

Alec Teal

@ABeautifulMind respect=lost

Committing to a challenge

Yes I am straight, I lived with my first partner for ~2.3 years and my current for ~2.66 years, both female

A Beautiful Mind

My partner is my pillow.

David Wheeler

09:46

Oh, you have a waifu?

Committing to a challenge

What the heck is a waifu

A Beautiful Mind

@AlecTeal Because I look like Justin Bieber in my younger days.

Alec Teal

That's no excuse to like him.

A Beautiful Mind

But I would never get a tattoo. I might try drugs though.

But drugs here are mostly illegal. So I have not tried them.

Committing to a challenge

I have no tattoos or piercings at all

I have never had a piercing(which is very uncommon in Australia)

ADG

09:48

Shut up random talkers/trollers

Alec Teal

Are you 12 @ABeautifulMind

A Beautiful Mind

I am what is considered 'a good boy'. I don't smoke or drink or take drugs.

Alec Teal

You seem like the person those cyber-nanny programs were invented for.

A Beautiful Mind

@AlecTeal Probably older than you, 34 this year.

Committing to a challenge

@DavidW My new assignment is mostly on lie algebra's, should I be scared?

A Beautiful Mind

09:49

@AlecTeal I like porn.

10

Committing to a challenge

@DavidW And the Vect category

David Wheeler

@Committingtoachallenge Do you already know about associative algebras?

A Beautiful Mind

I hope nobody flags me. I don't think anything is offensive.

Committing to a challenge

@DavidWheeler What does this mean?

@DavidWheeler He hasn't taught us anything in class that wasn't on the last assignment

ADG

Hope and reality. AH!

David Wheeler

09:50

@Committingtoachallenge What does "what" mean?

Committing to a challenge

So nothing on this assignment until after we hand in

@DavidWheeler What is an associative algebra referring to?

A Beautiful Mind

@AlecTeal I am 34 but never had a gf, LOL. Can you believe that?

David Wheeler

@Committingtoachallenge Do you know what a ring is?

Vogel612

@ABeautifulMind hmm.. thanks for the flags then......

it's starting to bubble to network wide, soo maybe you want to stop.

Committing to a challenge

@DavidWheeler I believe so, it is two operations that are groups

David Wheeler

09:51

@Committingtoachallenge No

A Beautiful Mind

@Vogel612 What was flagged?

Committing to a challenge

It is one operation that is a group and one that is not

Or was that a field

Vogel612

justin bieber and adult videos

Committing to a challenge

Yes that was a ring

David Wheeler

Your second answer is closer

Flyk

09:52

hello all of you mathematically superior individuals

Committing to a challenge

I think it was abelian addition and monoid multiplication

Abelian group addition

David Wheeler

@Committingtoachallenge That is (semi) correct

A Beautiful Mind

@Vogel612 I will stop, but worse things are said in the Eng room and nobody flags.

Committing to a challenge

And it distributes and closure of course

Vogel612

Which doesn't really make it okay, you know?

David Wheeler

09:53

Mathematicians differ as to whether or not rings without unity should be called rings

A Beautiful Mind

@Vogel612 However, if I post a link to an adult video in this chat, that should be flagged.

Vogel612

Offensive is always a subjective thing anyways and some room cultures are more forgiving than others

Committing to a challenge

So a ring is a abelian group binary operation, usually addition, and a monoid usually multiplication with a distributive axiom

Without unity?

David Wheeler

If the monoid is not commutative you need TWO distributive axioms

Committing to a challenge

Let's continue this discussion here(if you are willing)

A Beautiful Mind

09:54

@Vogel612 Exactly, so people decide if they want to flag or not, and I may or may not be suspended, which is fine.

Alec Teal

@Committingtoachallenge are you stuck on what a group is?

Committing to a challenge

@AlecTeal No

David Wheeler

Yes- the ring $2\Bbb Z$ has no multiplicative identity.

Vogel612

anyways I'm outta here again, since conversation is kinda over ;)

Committing to a challenge

@Vogel612 Cya :)

Alec Teal

09:56

@Committingtoachallenge would it be worth me filling in the "Field" page on that wiki?

Committing to a challenge

@AlecTeal Ring section maybe haha

Alec Teal

BTW google "Maths.kisogo.com Group"

the style of many proofs are there

A Beautiful Mind

@Committingtoachallenge No need to start a new room. I like everything in one place you know

Committing to a challenge

@ABeautifulMind But multiple conversations were occurring

A Beautiful Mind

I think this new room thing makes for too many rooms.

@Committingtoachallenge Which is fine as there is threading.

@Committingtoachallenge And also everyone can participate openly.

robjohn

09:57

@ABeautifulMind how did Justin Bieber look in your younger days?

A Beautiful Mind

@Committingtoachallenge And also you get to multitask.

Committing to a challenge

@ABeautifulMind I can't multitask well at all

A Beautiful Mind

@robjohn He looked like me in my youngest days. I think we were meant to be twins but somehow we separated. His father is also an asshole.

This asshole father, nice mother, abused child shit is pretty common in the world.

Alec Teal

....

A Beautiful Mind

Men are generally more abusive than women.

Alec Teal

09:59

Dude

A Beautiful Mind

Women can be abusive too, but it is not very often.

Committing to a challenge

You are probably going to get reported again lol

A Beautiful Mind

For saying?

Saying the facts of the world?

Committing to a challenge

For saying ahole twice

A Beautiful Mind

I think asshole used in certain contexts is fine. If one user calls another asshole in this chat for no reason then that is flaggable.

But asshole can even be used jokingly, like the following.

Hey Alex don't be an asshole.

Alec Teal

10:03

@Committingtoachallenge every time I've called you a bitch it has been with love

Just wanted you to know that.

A Beautiful Mind

Yeah, son of a bitch can be used lovingly you know, just watch Good Will Hunting.

Alec Teal

You should hear what I say on Xbox Live

A Beautiful Mind

Shall I say most people who flag me are just immature and superficial?

But if I say all people of a particular race or religion is ~!@#$, then that is definitely too much.

Flyk

@ABeautifulMind chat has a lot of that going around

A Beautiful Mind

And I never say such things in this chat.

Alec Teal

10:06

@Flyk it's not normally like this

Flyk

the problem is that each individual message has no context when flagged, people will just approve the flag based on the content of the message that was flagged

@AlecTeal meh, it has its moments

A Beautiful Mind

Sorry but the Eng room has influenced my chat culture to a large extent.

You go there and hear much worse things.

Flyk

I'm amazed you got that many flags and didn't get banned

that almost never happens

A Beautiful Mind

WHy is that so? Because my friends in high places are here? I don't know.

Alec Teal

@Flyk you tell someone on SO "Stop being a tard and RTFM" you get a 30day ban

they're oversensitive usually.

A Beautiful Mind

10:07

But I am not pushing it. I just feel like talking a lot today. Maybe it is the medication, lol.

Flyk

@AlecTeal like @ABeautifulMind says, it's all down to the individual norms of each chat room

Alec Teal

....

Flyk

we have some weird conversations in the DMZ that would get most people banned

Alec Teal

DMZ?

Flyk

same goes for the bridge, I guess

A Beautiful Mind

10:08

@AlecTeal On Eng, you tell them CTFD, check the dictionary you know

Flyk

@AlecTeal sec.se chat room

Alec Teal

Not sure what that is

Flyk

Information Security Stack Exchange chat room

@Committingtoachallenge flagged for cursing :P

A Beautiful Mind

@Committingtoachallenge All depends on the high ranking users online at that time.

:20610831 If you get a bunch of folks from Islam say, then you are definitely banned.

No, just a fact. No racism.

Flyk

:20610831 I didn't really flag :p

@ABeautifulMind I don't know, there are no statistics on which chat room generates the most flags

A Beautiful Mind

10:10

I think it all boils down to intention. If the intention is not malicious, no need to flag.

Flyk

but I know historically Mathematics is quite high on the list

A Beautiful Mind

@Flyk I think the Bridge, lol.

Flyk

@ABeautifulMind yeah probably the bridge is #1

A Beautiful Mind

@Flyk In math, we often get flagged for saying bananas.

For example, how long is your banana?

Flyk

that really is lacking a lot of context, though

@ABeautifulMind I don't have one!

A Beautiful Mind

10:11

@Flyk Oh, you are a girl! Hehe!

Flyk

well, I'm bored again now

A Beautiful Mind

Once someone said "I am awesome" and she got flagged in the Islam room.

Flyk

this was fun, see you soon (maybe, probably not)

Alec Teal

@Flyk please come back some day.

A Beautiful Mind

They treated the Islam chat like a mosque where women cannot promote themselves

@Committingtoachallenge When are you getting married? Waiting to have kids first or what?

Committing to a challenge

10:15

Hahaha in a few years :P

A Beautiful Mind

I wanna get married, maybe in my 40s, after I get well and go to grad school, if that even happens.

But I don't think I want kids.

First my kids will have my bad mental illness genes.

I don't wanna bring more suffering to this world

If you don't have the time to love your children, don't have any. Don't abuse them.

So many people have kids for the sake of having someone to abuse.

So many men marry for the sake of having a wife to abuse.

Then they get divorced and remarry, as if it is some kind of game.

All the marriage vows mean nothing to them

@Committingtoachallenge It's so sweet to have a gf that cares for you. =) You are very lucky.

Committing to a challenge

I know xD

In Australia most of the things you have said aren't true

and men don't abuse their wives much in Australia

A Beautiful Mind

I live in a society where I consider many parents to abuse their children and the government to abuse its citizens.

Parents treat children like puppets to serve their own emotional needs.

They don't treat them as separate individuals with distinct thoughts and emotions.

This is a super sick culture.

And yet these sick people are proud of this sick culture.

Mostly narcissistic personality disorders to me.

These people won't even get what I am trying to say because they like the life experiences and wisdom to even fathom the depths of these words.

Who cares if they are 60 years old?

Most people grow more stupid as they grow older, because they learn all the wrong things from this sick world.

Babies are born with this innate wisdom that is clouded by an imperfect society as they age.

iwriteonbananas

10:31

@ABeautifulMind i like porn too

A Beautiful Mind

Wow, I am talking TOO much.

@iwriteonbananas Let's not get flagged anymore.

iwriteonbananas

lets

Committing to a challenge

@ABeautifulMind I would talk more, but I am being taught stuff by David in the other room haha

A Beautiful Mind

@Committingtoachallenge Life is more interesting than math lol

Committing to a challenge

But my grades lol

Alec Teal

10:36

@Committingtoachallenge when you get rings sorted please fill out the page on the wiki

Committing to a challenge

@AlecTeal Alright :)

Alec Teal

I'll talk you through that later

Use {{Definition|Abstract Algebra}} and stuff so the categories are all dne

A Beautiful Mind

@Committingtoachallenge I think I am going to start a new math account and start answering questions again, lol.

Committing to a challenge

@ABeautifulMind Sounds good :)

@ABeautifulMind Well don't need to start a new one

@ABeautifulMind But answering questions is good

A Beautiful Mind

10:53

@Committingtoachallenge I wanna start afresh.

Committing to a challenge

@ABeautifulMind If you wish :). It is sad to kill your statistics on chat message counts

Committing to a challenge

11:05

@ABeautifulMind How was the doctor visit, I can't believe I forgot to ask

A Beautiful Mind

@Committingtoachallenge I got some fluvoxamine and clonazapam.

Committing to a challenge

@ABeautifulMind Are you feeling positive?

A Beautiful Mind

@Committingtoachallenge Slightly.

Committing to a challenge

That's great!

ᴇʏᴇs

11:28

@ABeautifulMind I hope you are feeling better

A Beautiful Mind

@ᴇʏᴇs A little for now.

A Beautiful Mind

11:53

Guys, I just changed my email address. Check your inboxes.

ᴇʏᴇs

I want a gmail e-mail

infinitesimal

12:10

@ABeautifulMind Hey

Gridley Quayle

Hi. I have two (not really related) queries, but I am not sure if they are substantial enough to be standalone questions. The first is 'If you can restrict the domain, do all mathematical functions/operations have an inverse?' (As I understand it an operation is a function in Abstract Algebra). The second question ' Is mathematics falsifiable?' Falsifiable in this context means 'has a converse' or
'can be refuted', I think some people define it as 'can be experimentally checked' or something in that vein.

Chris's sis

Greetings

infinitesimal

Greetings

ᴇʏᴇs

Greetings

A Beautiful Mind

Guys I am going to delete my current SE accounts, but I will be back with a new one very soon.

infinitesimal

12:15

NOOOO!!!

ᴇʏᴇs

@ABeautifulMind Will we be able to identify you

Chris's sis

I just had a great interview.

@ABeautifulMind Again?

A Beautiful Mind

@ᴇʏᴇs Yes. I shall call myself Jasper.

@Chris'ssis Yes. It will be the final time. Also check your inbox for my new email address.

infinitesimal

>>8((

Chris's sis

@ABeautifulMind OK

infinitesimal

12:33

Parth Kohli

@pleasedeleteme how many of them will you create?

Sahan

hey anyone who can help me with Parity??

ok no one i'm out!!

David Wheeler

12:56

???

Parity can have a lot of meanings

ᴇʏᴇs

Hi @DavidWheeler

David Wheeler

Hi, eyes have it.

ᴇʏᴇs

Unless you're a cyclops

David Wheeler

Or a noclops.

MathGod

can anyone tell me when does $\phi(k)$ divide $k$, where \phi is the euler totient function?

David Wheeler

13:07

2

Q: How do you find all $n$ such that $\phi(n)|n$

Where $\phi(n)$ is the Euler phi function, how do you find all $n$ such that $\phi(n)|n$?

elementary-number-theory

MathGod

Thanks :)

Jasper Loy

13:39

Hi guys, I am back with a brand new account and I can chat now!

I promise never to delete my email or SE account again!

infinitesimal

-_-

Jasper Loy

Please upvote my answer before I cannot chat again.

math.stackexchange.com/questions/1195456/… here.

David Wheeler

Rockin' that 23 rep

Jasper Loy

13:54

65 now, time to call it a day and retire, LOL.

Parth Kohli

@JasperLoy Riiiight.

Transcript for

$Mathematics$ Mathematics