The h Bar

barrycarter

17:00

Ocelot, the Dirac delta function brings tears to my eyes. ITS NOT A FUNCTION!!! ITS PEOPLE! SOYLENT GREEN IS PEOPLE!

0celo7

:)

Obliv

why can't it be $\mathbb Z$

0celo7

@Obliv what is $\mathbb{R}^{-16}$

Obliv

has to be a multiple of 2

wait..

that's still positive and in the reals

0celo7

what

Obliv

17:02

same as $\frac{1}{\mathbb R^{16}}$ isn't it

0celo7

@ACuriousMind Hmm.

@Obliv What the fuck is that

Obliv

which is in the $\mathbb R$? maybe?

barrycarter

@Obliv There is no set R^-1

Obliv

lol

why not?

barrycarter

@Obliv Well, how would you define it?

0celo7

17:02

$\frac{1}{\text{cat}}$ makes as much sense

barrycarter

I once divided a cat.

Obliv

$\frac{1}{\{1,4,2,6\}}$ is the inverse set :D

barrycarter

I prefer not to talk about it.

Obliv

copyright obliv 2016 ty

barrycarter

@Obliv Blargh, mind blown

Obliv

17:04

hey can't that work? Just inverse all elements?

barrycarter

@Obliv R^-1 doesn't mean 1/r for all elements in R

R^2 doesn't mean r^2 for all elements in R. It means all pairs {r1,r2} of real numbers.

Obliv

if it did, would $|\mathbb R^{-16}| = |\mathbb R|$?

barrycarter

Set multiplication (Cartesian product), not member multiplication.

@Obliv What is 0^-16 ?

Obliv

0

oh

barrycarter

No.

Obliv

17:05

shiet

barrycarter

And even if not, it wouldn't work because 16 is an even number.

So you'd just get R+ U {0}

R\R-

Hey, what happened to Ocleot?

Obliv

well actually what I said above was for it to be equal to $|\mathbb R^+|$

so it would have to a multiple of 2 otherwise you would get negative reals.

0celo7

@barrycarter I just realized I have no clue what's going on in class, bye

Obliv

wait no i'm confusing members with the values of each members again. eh gonna go back in the textbook now lol

barrycarter

No, we have chat logs. Oh, wait, I see your point.

Yes, they would be equal in size.

Chatting about physics during a physics class. Can there be too much love for physics?

2

Thanks to whoever starred that.

0celo7

17:11

@barrycarter We've been talking about math for the past hour.

barrycarter

Ocelot, math is all encompassing.

Physics is just an impure version of math.

0celo7

@barrycarter My blog contains mathematical physics

Slightly impure math

barrycarter

I like mathematical physics.

Math can be sullied for lesser causes, yes.

But, ultimately, once the diagrams are removed, the pure fresh glow of math will always shine through.

Except for the Dirac delta "function".

That's like the a-hole of math.

Slereah

Does the blog actually have any physics in it

IIRC all the proofs are just geometry

0celo7

Thankfully it never shows up in geometry

barrycarter

17:14

Tennessee?

0celo7

What

barrycarter

You're studying physics in TN?

Interestingish blog.

Obliv

if $f: A \to B,C$ is the domain of $f$ simply $A$ and co-domain of $f$ is $B$ and $C$?

or can $f$ not have two output sets?

0celo7

No, did you even read my profile?

barrycarter

The domain of f is A

I skimmed it.

0celo7

17:17

I'm not a physics student

barrycarter

OK, OK. Math/engineering (what a combo), but in TN

0celo7

@barrycarter yes

Why?

barrycarter

@Obliv I don't think your notation makes sense. B,C?

TN isn't the most advanced state in the union in terms of science.

0celo7

I plan to do physics or applied math in grad school, figured I'd double major in math

Obliv

can $A$ have an image through $f$ into two sets?

0celo7

17:19

@barrycarter Ouch

barrycarter

@Obliv Unless they mean B x C I don't think so

0celo7

We're right next to the largest lab in the country

barrycarter

OK OK, I won't bash TN anymore.

I'll prepare some additional material and bash it later.

0celo7

Have access to a nuclear reactor, synchotron and the second largest supercomputer in the world

Obliv

what is B x C? I'm not getting this from the book I'm just curious as to if what I wrote makes sense logically speaking

@0celo7 what's the first largest?

0celo7

17:20

Some Chinese one

@barrycarter do you think our profs deny evolution

And we come to school on tractors

Obliv

well there's no evidence so why wouldn't they? :P

barrycarter

Ocelot himself is the largest.

Obliv

tractors are pretty efficient honestly..

0celo7

@barrycarter I don't accept that the world existed before I was born.

barrycarter

Stop stealing my anti-TN material.

Valentin Tihomirov

17:23

Ok, I see that the length of Phi is 1.

barrycarter

OK, fine, you're the KY of the south.

0celo7

That's another plane of denial right there

@barrycarter what the hell does that mean

In TN we view KY as hicks

barrycarter

You're part of the Confederacy, right?

Valentin Tihomirov

But, what about mapping it to the \vec 0 and \vec 1 axes?

0celo7

What the fuck does that have to do with anything?

barrycarter

17:24

And KY is the other side.

I was complimenting you.

0celo7

My heritage is German and Czech

And I'm from VA

barrycarter

Still the south

0celo7

DC area

barrycarter

OK, good, German heritage, yes, that counters being in the Confederacy.

Valentin Tihomirov

The probabilities are 1/2 and 1/2 e^2iΘ are there, which dont' sum up to 1. Right?

barrycarter

17:25

RTP area?

@ValentinTihomirov Depends on your theta.

0celo7

Never heard of that acronym

barrycarter

Research Triangle Park?

0celo7

And you're on a fast track to my block list

barrycarter

Is that not a thing any more?

0celo7

That's in Maryland, no?

barrycarter

17:26

You blocked me earlier, remember?

I thought it spanned MD, VA, and DC

0celo7

@barrycarter I relented

@barrycarter not something they tell kids then

barrycarter

Do you think that my being on the fast track to your block list will temper my behavior?

0celo7

Either you don't care enough to talk to me, and I block you or you do care and will stop annoying me

Works out either way

David Z

@0celo7 if you want to block people, that's up to you, but there is no need to advertise it. Please don't.

Bernard Meurer

@0celo7 Your dad is awesome

barrycarter

17:28

Theorem: Barry cares to talk to Ocelot. talk(B,O). if talk(B,O) && block(O,B) -> dontcare(O,B)

0celo7

I'm letting him know @DavidZ

barrycarter

Your dad is famous?

0celo7

I'd appreciate if he wasn't annoying, am I allowed to advertise that?

@barrycarter Yes.

barrycarter

I was going to say this earlier anyway: I'm just joking, please don't take it seriously.

Who is your dad?

0celo7

@barrycarter I'm sure you are joking, but jokes can be annoying.

barrycarter

17:29

Well, it's banter, the kind of thing we do here.

0celo7

I'm the only one who is allowed to banter

barrycarter

And you're quite poke-able, if you know what I mean.

0celo7

Other banter offends me

Poking offends me

barrycarter

So, you get angry, David Banter?

OK, so who's your daddy?

David Z

@0celo7 speaking generally, if someone says something that annoys you, you can certainly point it out to them in a non-confrontational way.

Bernard Meurer

17:31

@barrycarter A person who's genuinely nice

barrycarter

@BernardMeurer Does he have a name?

0celo7

@DavidZ I like confronting people.

I'll confront you right now

Bernard Meurer

@barrycarter Yes, but it is none of your business :)

barrycarter

@BernardMeurer if he's famous, and everyone else knows...

Bernard Meurer

@0celo7 You're going to get yourself banned again

David Z

17:31

@0celo7 this is generally not a place for confrontation.

Bernard Meurer

@barrycarter Not everyone else knows

0celo7

@BernardMeurer For what

barrycarter

@BernardMeurer Oh great, so you just make the mysterious statement that Ocelot's dad is awesome.

Bernard Meurer

@0celo7 Confronting someone asking you not to confront

@barrycarter yes

barrycarter

Ocelot, if you want, we can get a room together and you can confrontational the hell out of me :)

Obliv

17:32

$g$ is an extension of a function $f$. That essentially means $f$ is bigger than $g$ in a way right? Since its domain is larger than g.

0celo7

@barrycarter I can tell it to your face

barrycarter

@Obliv Correct. g agrees with f where f is defined.

0celo7

Your institution have a solid state physics presence?

barrycarter

Do you feel that if we got another room, I would stop having a face?

Or were you suggesting something fairly untowards?

0celo7

I was going to shank you.

barrycarter

17:34

Anyway, I'm not going to churn. Chill out, Ocelot, I'm just kidding.

0celo7

I was too.

Knives are too messy

barrycarter

So you decided against the shanking?

Seriously, we're one letter away from British soft porn.

0celo7

Unless the opportunity presents itself, yes.

barrycarter

That's shank-tastic.

Bernard Meurer

shagalicious

0celo7

17:36

@barrycarter I don't think I would shag you

barrycarter

I didn't ask you to.

But thank you for pre-emptively saying no, just in case it comes up at some time in the future.

Bernard Meurer

@0celo7 What about me bae?

barrycarter

Would this be a permanent shag-ban, or may I assume that, as your tastes mature, you may change your mind?

0celo7

@BernardMeurer you're on my cheat list

barrycarter

Is he a celeb?

You can only add celebs.

Bernard Meurer

17:38

@0celo7 Because I won our little bet and am now discussing bald eagles with your father?

and you owe me 20 bucks

Obliv

if set $A$ is larger than set $B$ and $C$ is the set $A \times B$ do the ordered pairs where B no longer has a member at $a$ just return $\langle a,null \rangle$?

0celo7

Holy shit

@BernardMeurer this is insane

barrycarter

@Obliv Umm, no.

Best out of context quote

Obliv

isn't the cartesian product the ordering of all members of $A$ and $B$

barrycarter

@Obliv A x B doesn't require A and B to be the same size.

0celo7

17:40

@BernardMeurer I don't have the money

Bernard Meurer

@0celo7 You cast this onto yourself

Obliv

what would it return at the elements of $A$ where there is no corresponding elements of $B$? just a 0?

0celo7

@BernardMeurer will you take a book?

Bernard Meurer

@0celo7 I'll take beer & barbecue

Or Shankar :D

barrycarter

@Obliv What do you think A x B is if A = {1,2} and B = {X,Y,Z}?

0celo7

17:42

I need Shankar for my work @BernardMeurer

Bernard Meurer

@0celo7 Well that's the only book you have I'm interested in

You'll be paying me with some ribs

barrycarter

Hopefully pork or beef?

Obliv

I thought maybe $\{ \langle 1,X \rangle , \langle 2,Y \rangle , \langle null,Z \rangle \}$

Bernard Meurer

@barrycarter Human

barrycarter

@Obliv Umm, no. It's { {1,X}, {1,Y}, {1,Z}, {2,X}, {2,Y}, {2,Z} }

Obliv

17:44

oh i'm stupid. thanks @barrycarter

barrycarter

@Obliv its not per element multiplication, it's set multiplication

Obliv

ok

barrycarter

@BernardMeurer You know, Adam got a girl for a single rib. Settling a $20 debt for a rib seems pricey.

Bernard Meurer

@barrycarter haha

barrycarter

Although, I suppose there are places, like TN, where you can get a girl for $20

For an hour anyway.

0celo7

17:45

@barrycarter She's usually in the $30 range

barrycarter

Even on Toothless Bertha's House of Whores Wednesday Discount Night?

Oh, wait, I use the coupon, never mind.

Bernard Meurer

@0celo7 Who?

barrycarter

Toothless Bertha... the safe alternative for BJs.

0celo7

@BernardMeurer Rebecca

barrycarter

Backdoor Becky?

0celo7

17:48

@barrycarter you'll get a kick out of this one

My gf is from AL

barrycarter

Did she have a banjo on her knee?

Bernard Meurer

@0celo7 one of the babies picked food on his own !

0celo7

@barrycarter she can play the banjo with her tongue

barrycarter

I'm sensing an ornithological theme here.

You're a lucky man.

0celo7

Who said I'm a man?

barrycarter

17:49

Kin she also cook up a mess o grits real fine?

Boy

0celo7

I'm genderfluid

barrycarter

So you're a gender gas or a gender liquid?

Obliv

1) A binary relation on a nonempty set $A$ is a subset $R$ of $A \times A$ and we write $a~b$ if $(a,b) \in R$. Doesn't this make sense if it said a set $R$ instead of subset?

0celo7

@barrycarter Nonnewtonian gender

@barrycarter never asked, don't like grits

barrycarter

@Obliv Yes, it would still make sense.

A x A is a set, R is a subset of A x A

Obliv

17:51

I'm confused with this statement in general. $\{a,b\} \times \{a,b\}$ is just $\{\langle a,a \rangle, \langle a,b \rangle , \langle b,a \rangle, \langle b,b \rangle \}$. so like where is the relation even present?

Bernard Meurer

@0celo7 I'm a non-hausdorff

0celo7

@BernardMeurer are you really coming to Memphis this summer

Bernard Meurer

@0celo7 I might, dunno yet, gotta check on the $$

barrycarter

@Obliv No, they're saying that a binary relation is some subset of A x A

0celo7

Or is it Nashville?

barrycarter

17:52

Like the relation "<" on {1,2,3} would be { {1,2}, {1,3}, {2,3}}

0celo7

I can't remember Michelle's plans

Obliv

oh..

Bernard Meurer

@0celo7 The barbecue's in memphis

barrycarter

@Obliv I'd invite you to go private and do some "real" math, but I'm afraid I've only allocated half a day to waste on chat today, and that ends in 6 minutes.

Obliv

@barrycarter I'm just learning definitions/preliminaries of this book still LOL. But, I've learned a lot so far and I'm thankful for your help thus far.

yeah I get that $R$ is just a subset of the total cartesian product of the set on itself.

barrycarter

17:54

@Obliv Sure thing. It sometimes seems like you're jumping around randomly in the book. Is this the case?

Correct, a relation is a subset of A x B. In this case B=A

Obliv

no. I think of things sometimes not mentioned in the book otherwise I'm going chronologically.

just curious, how come you never use latex commands @barrycarter

Bernard Meurer

@0celo7 Shit, flights to knoxville are SO cheap

barrycarter

@Obliv I'm allergic to latex

Obliv

what a rare condition..

barrycarter

Yes :P

Bernard Meurer

17:55

@0celo7 400USD the two way

barrycarter

I don't know TeX that well.

And I think it sometimes obfuscates instead of elucidates.

0celo7

@barrycarter literally never true.

Obliv

just look up commands as you go and you'll learn quickly. I think it makes things cleaner.

barrycarter

What, Ocelot?

Obliv

instead of x^2 + 2 you have $x^2 + 2$ :D

barrycarter

17:57

@Obliv I'm a TeX hold out

Plus my stupid browser won't render TeX unless I visit the bookmark each time.

Superscripts are for wimps.

Bernard Meurer

@barrycarter $\LaTeX$ is always better

barrycarter

It looks nicer, maybe.

0celo7

How could it make things more confusing

Obliv

i used the link on the top right of this page to get a bookmark that renders any tex on the page. you only have to click it once unless you close the page

0celo7

Ever

barrycarter

17:58

Besides, he asked me about latex, not LaTeX :P

0celo7

The answer is that it doesn't

barrycarter

@Obliv That's how it's supposed to work, but it's broken somehow for me. It used to work fine.

Obliv

It works for me on chrome & nightly

barrycarter

Well good for you :P

Obliv

i'm guessing it would work on firefox too

barrycarter

17:59

Yes, it used to. I probably just need to look into it, but I don't care.

0celo7

You have to click chatjax every time you refresh

Did you bookmark it?

barrycarter

In my case, I have click chatjax even when I don't refresh.

Yes, its bookmarked.

It's a browser issue on my side.

0celo7

What browser?

barrycarter

Firefox old version

0celo7

My god

Use Chrome new version

Obliv

18:01

shouldn't the statement I said above actually be a relation instead of a binary relation?

a binary relation is between 2 elements. So it would be a set of 1 ordered pair? o_o

ACuriousMind

I think you should take a step back and go about this a bit slower. I don't think you've gotten a single definition right from what you've posted thus far.

Obliv

my book said that was what a binary relation was.. it lied

Bernard Meurer

@ACuriousMind Do you want to watch bald eagles with me?

ACuriousMind

Read the definition. Then read the examples (if the book gives no examples, switch to one that does). Think about why every example is actually an instance of the definition.

@BernardMeurer Is that a euphemism?

Bernard Meurer

@ACuriousMind ustream.tv/channel/Ws8PbVWq5Xs

Nope

Obliv

18:05

nevermind it defined it correctly. I have no idea why I thought it was something else.

is there even a formal definition for just "relation" between objects?

ACuriousMind

6

Q: Is watching porn in university a crime?

I am about to start my graduate studies in an American university, moving from my native Peru. Over the course of my under-graduation, I have developed this strange habit of watching porn at odd times, say afternoon, or morning. Sometimes I watch in classroom too, of course, reducing the volume t...

the fuck is this?

Obliv

LOL

that's so fucked. porn is just such a stupid thing and for him to think it's okay in academia is just despicable.

barrycarter

@Obliv I got a reprieve. I can help you w/ math in a private room away from all these "physicists" provided you don't make fun of my little latex problem.

But it's not a crime.

Obliv

well unless my questions aren't wanted I feel like asking to an audience is better than having a single source. no hard feelings @barrycarter I like mathematicians and physicists equally :p

ACuriousMind

@barrycarter If you read the question, it's more about whether it is considered acceptable, the title is a slight misnomer

barrycarter

18:12

@Obliv Fair enough, I'm getting a little distracted, but I can keep trying to help

ACuriousMind

I'm baffled that this needs to be asked, though.

Obliv

thanks.

barrycarter

@Obliv As you learn more, you will understand why mathematicians are better :P

ACuriousMind

Then again, I'm regularly baffled by what passed for a good question at academia.SE, so that doesn't say much... :P

Obliv

the internet allows for people to ask idiotic questions without feeling bad. If he asked that to a public audience in real life, i'm sure he would feel a lot different. @ACuriousMind

barrycarter

18:13

Sounds more like an April Fool's Day prank

I, personally, would cheer him on.

Obliv

why...

barrycarter

Porn is awesome

Obliv

i'm so tempted to star that.

barrycarter

Go for it :)

It can provide a good break from studying.

Obliv

but why IN the class?

barrycarter

18:16

Hmmm, OK, that one's a bit weird.

Obliv

just a bit.

barrycarter

I mean, if the class itself isn't getting you excited, you're taking the wrong class.

Real mathematicians don't need porn (to do mathematics)

ACuriousMind

@barrycarter Relevant SMBC

Obliv

many people don't realize what porn-addictions can do to people. People just do stupid things when they aren't in control of themselves when those instincts kick in.

barrycarter

@ACuriousMind Ouch! I'd say the exact opposite.

@Obliv I am not aligned to your political views.

I do think porn is awesome, but agree that in class is not a good time to view it.

Obliv

18:45

A partition of A is any collection $\{ A_i | i \in I\}$ of non empty subsets of A (I some indexing set) such that a) $A = \cup_{i \in I} A_i$, and b) $A_i \cap A_j = \emptyset $ for all $i,j \in I$ with $i \ne j$ (i.e, $A$ is the disjoint union of the sets in the partition).

I have a question about the definition of this partition

What does $\cup A_i$ mean? Does it mean the union of all the partitions of A?

Tuntuni

Yes

Obliv

Also, does $A_i \cap A_j = \emptyset$ mean they never intersect?

Tuntuni

That's right. No elements in common.

Obliv

thanks

Tuntuni

No problem. :-)

Obliv

18:56

if ~ defines an equivalence relation on $A$ then the set of equivalence classes of ~ form a partition of $A$. Is this essentially saying the binary [equivalence] relation on $A$ is a subset of $A$?

a partition of $A$ is a subset of $A$, right?

yuggib

19:13

no, a partition of a is a set of subsets of $A$

is a subset of $2^A$

the set of parts of $A$

barrycarter

19:31

It's a way of breaking A into disjoint subsets that make up all of A

Obliv

19:55

when it says the set of equivalence classes of ~ , is that equivalent to saying the binary relation on A using the ~ relation?

also @ACuriousMind is it true that carbonated water is the default water in Germany?

user507974

@Obliv is that what mineral water is

Obliv

don't ask me..

probably?

ACuriousMind

@Obliv If you mean that you'll get carbonated water when simply ordering "water" then yes, although many servers will ask what exactly you want.

barrycarter

@Obliv Sort of, yes.

ACuriousMind

@Obliv That sentence doesn't really make sense to me, but if you're asking whether the set of equivalence classes is the same as the relation as a subset of $A\times A$, then no.

Obliv

19:59

any other countries where they do that? My friend says that he always half-expects drinking carbonated water when he takes a sip of water now. Traumatizing experience smh

Transcript for