Mathematics - 2021-03-22 (page 1 of 3)

Ted Shifrin

00:00

Clarinet, can you explain the error in my thinking? If the sum of independent Poisson RV is again Poisson with the sum of the means, why is the average of $3$ with the same mean different from a single Poisson RV with that mean?

I grant I haven't thought about this stuff in 6 years, but ...

user2103480

I wrote everything about this above

dc3rd

You know what.........I didn't get that because my thinking is out of whack. I've been working on it conciously, but this is a vivid display of actually having to apply the concepts in ways that are not exactly like in the textbook......alluding to the discussion you guuys were having a few days ago about poor fundamentals and expecting to copy examples from the text to get an answer

Ted Shifrin

What you wrote above (not counting the f***ing) made no sense to me, since I'm not a probabilist. What does yield fractional values mean?

@dc3rd: My book is going to be like that throughout. With analysis it gets far trickier.

mick

hi all

dc3rd

😭😭...I need the mind blown emoji right now......this is precisely what I signed up for when taking my time off from my university studies, so I'm all for it...

mick

00:03

0

Q: Nonassociative algebra's closed under $\sqrt{}$?

Consider a non-associative commutative unital algebra of finite dimension where the product is defined by a cayley table such that elements are generated with real number coefficients $(a_0, \dots, a_n) $ for a basis $\{1, i_1, \dots, i_n \}$ and we have a basis so that $ i_k^2 \in \{ -1, +1 \}$....

user2103480

@TedShifrin poisson has integers as values. The sum of three poissons divided by three can have values such as 1/3 + 2/3 + 1/3 = 4/3 which is not an integer

dc3rd

this is REAL analysis....actually using the techniques......this is going to be ardourous, but rewarding....fortunately I'm a masochist for this stuff

Clarinetist

@TedShifrin A Poisson random variable takes on values in $\mathbb{Z}_{\geq 0}$. The sum of three values in $\mathbb{Z}_{\geq 0}$ is also in $\mathbb{Z}_{\geq 0}$. Divide by three, and you end up with fractional values, outside of $\mathbb{Z}_{\geq 0}$.

Ted Shifrin

I see. Thank you both.

dc3rd

well that expenditure of brain power merits me eating the leftover caccio e pepe I have

Ted Shifrin

00:05

So the average of identical Poisson is not Poisson, even though their sum is. I understand now.

I will never again attempt to answer probability/statistics. Never.

anakhro

@dc3rd 🤯🤯🤯

Ted Shifrin

Enjoy it, @dc3rd.

robjohn

My phone has $\unicode{x1f92f}$ but my computer doesn't.

need to update my OS

geocalc33

🤯

🤬🤬🤬

Ted Shifrin

I don't get all the emojis in here that I get in iMessage.

Clarinetist

00:08

@ChairmanMeow Challenge question: can you find an unbiased estimator for $e^\theta$?

(I think I know how you would do this... it's been a very long time)

Ted Shifrin

Speaking of Meow, I wonder what's become of MeowMix!!

mick

anyone willing to look at my question ? pretty please

Clarinetist

@mick Just ask it

Oh

Sorry, I missed it

I haven't thought about abstract algebra since 2014

mick

@Clarinetist thats ok. upvote and answer and i forgive you :)

Clarinetist

I'll give you an upvote, unfortunately don't know enough to give an answer

mick

00:10

@Clarinetist cool :)

geocalc33

shouldn't you capitalize Cayley?

Chairman Meow

@Clarinetist That is indeed a challenge question. Would you need to find a constant to do that?

mick

@geocalc33 maybe

Clarinetist

Let me see if I can do it... it's been a very long time.

mick

i capitalized for you my friend :)
now upvote :p

@Clarinetist thanks

geocalc33

00:15

I'll give you a bookmark

user2103480

Now what I originally wanted to write: Physicist's math is marvellous. Assume we have random variables which can be propagated forwards in time (by a Hamiltonian), so in formulas $\partial_t A = i\mathcal L A$. We simply formally solve this as $A_t = e^{i\mathcal L t} A_0$, and do the same for some $B_t = e^{i\mathcal L t} B_0$.

Now we want to compute a laplace transform of the autocorrelation function and continue to treat the operators like usual numbers to get $$C_{AB}(t) = \Bbb E[A_t^\ast B_0] = \Bbb E[(e^{i\mathcal L t} A_0)^\ast B_0] = \Bbb E[A_0 e^{-i\mathcal L t} B_0]$$

Clarinetist

@ChairmanMeow Old question I asked:

2

Q: For what values of $k \in \mathbb{Z}\setminus\{0\}$ does there exist an unbiased estimator of $e^{k \lambda}$?

This is inspired by Finding an unbiased estimator of $e^{-2\lambda}$ for Poisson distribution, reminding me of a qualifying exam question that I was frustrated with. Suppose $X_1, \dots, X_n \overset{\text{iid}}{\sim}\text{Poisson}(\lambda)$. For some subset of size $k \leq n$, it can be seen t...

probability probability-distributions poisson-distribution parameter-estimation

Chairman Meow

@Clarinetist cool!

Clarinetist

I forgot I asked that question until a minute or two ago

There was a question on one of my master's qualifying exams where a similar question came up

user2103480

@leslietownes is this how semigroup theorists do operator calculus

Ted Shifrin

00:19

@Clarinetist Wait 'til you're my age!

Clarinetist

Lol

user2103480

just act as if literally everything works out and in the end it does?

Chairman Meow

That is really interesting and motivating!

Clarinetist

I resigned from my faculty position on Thursday... leaving at the end of Spring. Can't sufficiently express how relieved I am.

Unknown x

if a rational function has horizontal asymptode y=-2. the the numerator and denominator must have the same degrree of polynomials.right?

Ted Shifrin

00:22

Mazltov, Clarinet!

Chairman Meow

I have one last question about my question and then I am done torturing all of you nice people and myself. So since I have found the mgf of $$e^{\frac{\sum^3_{i=1}X_i}3}$$, then this should agree with the left hand side of my invocation of Jensen's inequality, which happens to be $$E\left(e^{\frac{\sum^3_{i=1}X_i}3}\right)$$, right?

Ted Shifrin

Yes @Unknownx

Unknown x

@Ted shifrin. Thank you very much :)

Ted Shifrin

Sure.

Clarinetist

@ChairmanMeow Set $t = 1$ and you're good.

Chairman Meow

00:24

@Clarinetist thank you so so much!

user2103480

@ChairmanMeow can you specify what you intend to do? What function are you applying Jensen's to?

Ted Shifrin

Clarinet, was the discussion amicable?

Clarinetist

Yes, the department chair wasn't surprised. I can tell it's going to be difficult for them logistically, but I could tell he understood why I couldn't continue doing that position.

I'm hoping they get their new full-time hire in on this. Adjunct pay just wasn't worth it for me to keep going.

geocalc33

when you change coordinates you can change how a partial differential equation looks and the solutions change

Clarinetist

Plus I would really like to see some commitment from their full-timers on this class if they really are serious about continuing the program.

Chairman Meow

00:27

@user2103480 I am trying to show that $$^{\frac{\sum^3_{i=1}X_i}{3}}$$ is not an unbiased estimator of $$e^{\theta}$$ two ways. Using Jesnen's inequality and mgfs, just to see how they compare.

Ted Shifrin

I'm glad it was a fair discussion, Clarinet.

Clarinetist

I am too.

I know they're going to have bigger fish to fry than my class, though. The dev-ed/remedial math conversation is going on nationally.

That is a conversation that I'm glad I've not had to be a part of.

Ted Shifrin

I have been a part of it at the university level over the years.

dc3rd

So $x-u = s(v-u) + t(w-v)$ is a "shifting" of my whole object, whereas $x - u = s(v-u) + t(w-v) - u$ is traveling on a vector in the shifted object

Clarinetist

I think the movement is slowly moving toward eliminating it entirely

Ted Shifrin

00:33

Eliminating what, Clarinet?

Clarinetist

Dev-ed/remedial math

Not that I agree with it, but I'm observing.

At a national level.

Ted Shifrin

It really doesn't make good sense, @dc3rd. It then defines something dependent on where the origin is.

dc3rd

in the second case no?

Ted Shifrin

Well, secondary schools will have to actually give students the skills in a provable way, Clarinet.

Yes, the second.

Clarinetist

My guess is what will happen is that post-secondary institutions will eventually get rid of dev-ed/remedial classes in favor of just placing students directly into college-level math classes, because the benefits (higher graduation rates, higher retention) outweigh the risks (people not being ready for college-level math).

dc3rd

00:36

Ok. I'll remember that.

Mark Giraffe

Enjoying the headers I've been making. Trying to make a proper dark mode version of it...

Clarinetist

It is a consequence of a metric-driven environment. I don't agree with it.

geocalc33

metric?

user2103480

@ChairmanMeow I think you meant to write $e^{\frac{\sum^3_{i=1}X_i}{3}}$. Okay, I see. In one case, Jensen yield's strict inequality since the exponential is not affine, in the other case you calculate an explicit formula for the expected value and I guess it's left to show that this is not equal to $e^\theta$

Ted Shifrin

Well, I'm all in favor of doing a better job in primary and secondary schools across the board. Parents need to demand that and society needs to respect teachers so that better folks go into teaching.

Clarinetist

00:40

I agree. K-12 has a whole host of issues right now distinct from higher ed. I don't miss that world.

Ted Shifrin

Community college and a lot of university curriculum is largely remedial to cover that defect.

Chairman Meow

@user2103480 yes that is completely correct. Now I am just making sure both agree.

Ted Shifrin

And then there are the high schools determined to teach multivariable calc and linear algebra. The hell with that. AP calc is bad enough.

Clarinetist

One of the biggest problems in K-12 IMO is that standardized testing is tied to funding mechanisms, and then indirectly where people live for real estate

geocalc33

0

Q: Is $\zeta$ a solution to the Einstein field equations?

Consider a Lorentzian manifold $(\zeta,g)$ with metric $g=\frac{dudv}{uv}-\frac{dr^2}{r^2}-\frac{dw^2}{w^2}.$ Clearly $\zeta$ is diffeomorphic to Minkowski space, $\Bbb R^{3,1}.$ $\zeta$ also has zero curvature like Minkowski space. Is $\zeta$ a solution to the Einstein field equations? I know ...

differential-geometry general-relativity semi-riemannian-geometry

Ted Shifrin

00:43

Yup, racially and economically super-biased.

Mark Giraffe

$ 0^0^0^0 $

Clarinetist

If the federal legislators do to higher ed what they did to K-12 - which is extremely plausible, but was delayed due to COVID - we may see the same thing happen in the undergrad years.

mick

@MarkGiraffe what ??

Ted Shifrin

I want legislators gone and buried.

Clarinetist

I'm honestly surprised how few people I've met in higher ed who have heard of the Higher Education Act.

Mark Giraffe

00:46

@mick Trying to make an exponent exponented by another exponented exponent.

Ted Shifrin

Have not or have?

Clarinetist

have*, thanks

Ted Shifrin

Pell grants, etc.?

Clarinetist

Yep. Drives higher ed funding. One massive bill that has to go through a long renewal process every so often.

Mark Giraffe

$ 1^2^3^4^5^6^7^8^9^10 = 1 = $ damn, what a waste, remove $1$ please to make it more interesting.

Okay.

Ted Shifrin

00:48

Interesting?

Mark Giraffe

$2^3^4^5^6^7^8^9^10 = ?$

Clarinetist

K-12 has an analogous bill called the Elementary and Secondary Education Act (ESEA). No Child Left Behind was a specific renewal of the ESEA, and that's what primarily drove standardized testing as a requirement.

Pre-COVID, the process began to renew the Higher Education Act (HEA). The process was completely derailed by COVID, but the priorities were clear from both major parties: more accountability in higher ed.

geocalc33

2^2=4

Ted Shifrin

Yes, legislators love the idea of outcome-based budgeting and post-tenure review, ultimately killing tenure.

Mark Giraffe

$2^3 = 8$
$8^4 = 4,096$
$4,096^5 = 1,152,921,504,606,846,976$

At this point, it is going to be a Stack Overflow.

geocalc33

00:51

at this point it's going to be more than the galaxies in the universe

Ted Shifrin

I actually support getting rid of some university faculty who are total deadwood.

Mark Giraffe

@geocalc33 Indeed.

Clarinetist

Yeah, I don't know enough about promotion & tenure to be able to comment how that would be done

Ted Shifrin

My hardest task as associate head was assigning teaching to people who hardly did research at all and were completely incompetent at teaching.

Mark Giraffe

$1,152,921,504,606,846,976^6 = 2.3485425827738332278894805967893e+108$

Yeah, very beeg.

geocalc33

00:53

fun fact: galaxies come in different shapes and sizes

PM 2Ring

@MarkGiraffe You're doing it backwards. $a^b^c=a^(b^c)$.

Mark Giraffe

Is 4D on-topic on Math SE?

Ohh.

geocalc33

what's 4D

PM 2Ring

That's because if you want $(a^b)^c$ you'd write $a^{bc}$

Mark Giraffe

$9^10 = 3486784401$
$8^3486784401 = StackOverflow$

Why is MathJax still wrong??

anakhro

00:58

If I have a family of maps $\{f_n\}$ such that $f_n = h\circ g_n\circ h^{-1}$ for a biholomorphism $h$ and the family $\{g_n\}$ is normal, is $\{f_n\}$ then necessarily normal?

(complex maps, normal being the complex term for "precompact")

Mark Giraffe

@geocalc33 The four spatial dimensions. We have 3: $x$ (length), $y$ (width), $z$ (height).

Ted Shifrin

I am not going to think hard, but I would guess yes without thinking, anakhro.

anakhro

That was my thought without thinking, too. :P

geocalc33

four dimensional mathematics is the essence of mathematical thought

Ted Shifrin

But you are paid to think !

geocalc33

01:00

I can't imagine it not being on topic

Mark Giraffe

I kept of thinking that the $4th$ might be depth, thanks to the construction of the tesseract that some would think of.

Where the cube could be inside the cube based on illustration on a flat plane.

I actually tried making a tesseract in Minecraft.

Thorgott

what does precompact mean for a map

PM 2Ring

@MarkGiraffe You need braces on the exponent: 8^{3486784401}. BTW, that number has 3,148,880,080 digits (in decimal).

anakhro

@Thorgott precompact set of maps.

it's a family of maps, not a single map.

So you give it (the set of all maps you are concerned with) a topology and precompact makes sense.

geocalc33

wow that's interresant

Thorgott

01:05

ok, which topology is it in this case

anakhro

Compact-open topology.

PM 2Ring

@MarkGiraffe See physics.stackexchange.com/q/621590/123208 & the comment by DJohnM which links to a PDF of Heinlein's "And He Built a Crooked House".

PM 2Ring

01:17

Here's a rotating tesseract projection built with three.js that you can interact with: mikelortega.github.io/tesseract

Mark Giraffe

Are your eyes hurting yet?

love_sodam

In an arbitrary vector space $V$ (in particular vector space can be infinite dimensional), for given point $v\in V$, can we always form a basis $B$ containing $v$?

Ted Shifrin

Nonzero?

Leaky Nun

any linearly independent subset can be extended to form a basis (basis extension theorem)

proof: use Zorn's lemma to pick a maximal linearly independent subset containing the given set. if there is something outside the span, then adding it to the collection would produce a larger linearly independent subset, contradiction.

Thorgott

01:43

but false without choice

Leaky Nun

thanks

really needed that

Edward Evans

Thorgott strikes again

user2103480

02:02

@Thorgott important fact

Thorgott

the importance of this fact is directly proportional to how much of a logician you are

user2103480

always surprised that not AC => vector space without basis exists was proved in 1984

love_sodam

@TedShifrin yes

@LeakyNun Nice

zacts

02:55

@MarkGiraffe that kind of reminds me of this book: mitpress.mit.edu/books/…

leslie townes

03:22

a vector space is an imaginary construct. i believe in R^n and some L^2 spaces.

leslie townes

03:40

also C^n.

copper.hat

04:13

Q^n?

leslie townes

no, i don't acknowledge that. it feels like a scam to me.

what are they hiding? i think we should all ask ourselves that.

copper.hat

I did mean quaternions, but why not rationals?

Thorgott

@leslietownes same thing as R^n

for different n, admittedly

leslie townes

that's where they get you.

copper.hat

B^n

leslie townes

04:17

different n, indeed.

copper.hat

doesn't get any simpler than that

from hamilton to boole

my alma mater was boole's college

leslie townes

my wife just had her second shot. i'm in the same house as someone who has been implanted with a bill gates microchip.

boole had a number of very good ideas.

copper.hat

there are 10 types of people in the world

how come your wife gets a shot?

health professional?

presumably <65

leslie townes

she is an educator. they're trying to get teachers back into classrooms. that's not happening in 2021. but that's how she got it. she isn't even 40.

copper.hat

nancy pelosi's hairdresser?

sabine schmitz died a few days ago. sad day.

leslie townes

04:22

pretty much. my best friend lives in beverly hills and goes to the same hairdresser as people we all have heard of.

i saw that. that sucked.

copper.hat

awesome topgear episode with her

my brother tested positive after his second pfizer shot

admittedly 37 pcr amplifications later

leslie townes

my wife and i both had horrible symptoms in november. i couldn't taste anything for about a month.

PCR is a funny reaction.

copper.hat

covid or a bad can of spam?

leslie townes

i try to eat vegetarian as much as possible, so the food is mostly flavorless.

copper.hat

india vegetarian is far from flavourless...

leslie townes

04:25

yeah, i wish we lived in india.

copper.hat

one of my favourite dishes is palak paneer

then again, a good lamb biryani does the trick too. not quite vegetarian though...

leslie townes

i used to cook for us. it was OK. but for about a month it was, absolutely no sensation. probably covid? i don't know.

copper.hat

i had some great vegetarian food in china

and indonesia

dang, time for dinner #3.

met some friends for dinner & drinks at the biergarten in berkeley

leslie townes

chinese cuisine is great. it is hard to get those places locally. everything is adapted to an american taste.

copper.hat

got home and had some ribs with wife & son

chinese food in china is a lot different than chinese food in america

i am sure brendan behan has a saying about that

leslie townes

04:30

my grandfather, who loved quoting him, was about the same vintage.

copper.hat

a brilliant man.

behan too :-).

pithy is how my mother described him. that meant he said things she did not approve of.

i imagine he was a fun drinking companion, much like shane mcgowan

leslie townes

my wife doesn't understand when i say "your man" in reference to somebody inextricably tied to the story but not named. it's your man. i don't need to give more references.

copper.hat

'yer man

culture is a hard boundary to cross

leslie townes

i got it from my grandfather. he was a gambler and completely unreliable.

copper.hat

sounds like a fun companion :-)

i am in desperate need of drinking companions. usually easy to find, but covid has ruined things

leslie townes

04:34

covid is a piece of shit.

copper.hat

it has screwed my 17 yos son's life

leslie townes

i can't imagine being at the threshold of life and then all of this garbage.

my daughter is two years old. she has no idea how weird all of this is.

satan 29

@leslietownes :(

attending college at home sucks.

copper.hat

yep. plus many of last year's cohort are applying this year too

leslie townes

i would be out of my mind right now.

Rajorshi Koyal

04:44

Please tell me how to solve this

copper.hat

why don't you ask your question on mse?

Rajorshi Koyal

On main site you mean?

Why are they taking ratios here @copper.hat

It is a small query

@copper.hat It would be extremely kind of you if you suggest me a different chat room in case you do not find it good.

But it doesn't qualify to the standards of a main question

Mark Giraffe

05:05

I did it.

user 85795

is this for the j e e @RajorshiKoyal?

Mark Giraffe

Slightly adjusted.

Rajorshi Koyal

@user85795 For IBPS PO

user 85795

Ok, try here @RajorshiKoyal

Rajorshi Koyal

That is for physics na

Rajorshi Koyal

05:27

Sorry

Rajorshi Koyal

05:56

@user85795 Tq for suggesting

user 85795

np

Wolgwang

10:22

Is there a query on Data Explorer that gives the number of views on a particular question by days?

jay

12:41

Hi guys in search of some tech help here! I want to download my beamer slides and view them on an application that allows me to draw on them and preferably has an option of a laser pointer for the mouse. ( for giving a presentation). Can someone recommend a application? Im on PC

windows

porridgemathematics

13:37

apparently $H_n(S^n) \equiv H_n(S^n , S^n \setminus \{pt \})$ for all $n > 0$, and one can see this using the long exact sequence of a pair, but I don't see how the LES of a pair method applied for $n=1$, namely we get $0 = H_{n}(S^n \setminus \{pt \}) \rightarrow H_n(S^n) \rightarrow H_n(S^n , S^n \setminus \{ pt \}) \rightarrow H_{n-1}(S^n \setminus \{ pt \})$, which is of the form $0 \rightarrow A \rightarrow B \rightarrow 0$ for $n > 1$

but for $n=1$ its of the form $0 \rightarrow A \rightarrow B \rightarrow \mathbb{Z}$ , what am I missing?

the justification my lecturer states is that $S^n \setminus \{pt \}$ is contractible, so its homology is zero, surely its zeroth homology is still equal to the number of its path components though, which is equal to one regardless of what $n$ is?

Alessandro Codenotti

Usually you want reduced homology to make statements for all $n$ with no weirdness when $n=0$, maybe this is one of those cases

porridgemathematics

oh you're totally right, we want the following LES : $...\rightarrow H_1(S^n \setminus \{pt \}) \rightarrow H_1(S^n) \rightarrow H_1(S^n, S^n \setminus \{pt \}) \rightarrow \tilde{H_0}(S^n \setminus \{pt \})$ which is of the form $0 \rightarrow H_1(S^n) \rightarrow H_1(S^n, S^n \setminus \{pt \}) \rightarrow 0$, although this is really coming from the LES of the triple $(\{x \}, A , X)$ where $x \in A \subset X$

jeea

14:06

if $S = \sum_j a_j^nb_j$ and $T = \sum_ja_j^{n-1}b_j$ and $S$ converges, then can we show convergence of $T$ like this: let $m = \max(\frac{1}{|a_j|})$ then $|T| \le m|S|$ ?

Clarinetist

@jay I use PDF Annotator, but I recall it has a fee. It is worth it, though, if this is what you do often.

For mouse laser pointers, I have no idea.

leslie townes

14:22

i just did a pinch harmonic by accident and it sounded badass. i felt like i was in zz top.

this is going to be a good week.

anakhro

nice

what kind of music do you like, Leslie?

leslie townes

lately, jazz guitar. i have a couple of pat martino records on constant loop. i also go through phases where i only want to hear electronic music that came out when i was a teenager.

anakhro

Do you play anything funky?

leslie townes

not lately but historically yes. i lived in oakland for ten years. it is in my veins.

i just queued up mahavishnu orchestra's "can't stand your funk." it holds up.

anakhro

Armstrong on the basssss

leslie townes

14:32

the most weed i have ever seen at a show was a herbie hancock concert. i must have been the youngest person in there by 25 years. old people really like weed.

now i'm listening to tony williams' "life time."

anakhro

Listen to some Jamiroquai.

jay

I watched the Amy Winehouse documentary "Amy" yesterday, so tragic :(

leslie townes

entertainment is a toxic industry. people go to your shows hoping to see how f-ed up you are. anything for a spectacle.

anakhro

Similar for lectures by famous mathematicians. ;)

Edward Evans

I go to shows to show people how fucked up they can get

big hobby

leslie townes

14:43

i was a fan of the comedian mitch hedberg. the last show i went to, he was obviously out of his mind on opiates. almost everyone in the audience found it funny. it wasn't that funny.

i do remember people going to lectures from famous mathematicians just to, like, check them off a list. "why are you going to that? you won't understand anything." "it's sir michael atiyah." or whatever.

i went to a talk once and i was like "wow, this guy is really good." i didn't know who it was. it was VI Arnold.

jay

yeah I saw that pretty sad.

leslie townes

i remember thinking "they should get this guy to come back next week."

anakhro

lol @ Arnold

leslie townes

he was an amazing lecturer. a high schooler could have understood it. it went from well known theory to open questions. i hope his brain is in a jar somewhere so we can reanimate it and get more out of him.

anakhro

He did do a popular series of lectures for high school students.

jay

14:51

How are Humans going to cope in say 50 years when every discipline has become so in depth ? will take 30years to get up to date and will take another 30 to change fields...

anakhro

@jay that won't happen for a long time. Right now math is a very shallow set of roots, with many, many roots.

leslie townes

things go in depth as a consequence of simplification. we realize that many things that previous generations struggled with are not necessary. we truly do stand on the shoulders of giants. and it's completely free. there's no limit to simplification.

imagine all the wasted ink about, like, the propriety of non-euclidean geometry. or people notating calculus in different ways. very smart people completely preoccupied with the wrong things.

almost everything will one day seem like a nightmare from which we have awakened.

anakhro

Except for the intermediate value theorem, that one seems important.

leslie townes

we can keep the IVT.

my wife had her second covid vaccine yesterday. i've been monitoring her to see if bill gates is controlling her mind. so far it looks like she retains some independent agency. but that could be part of the program.

jay

in the uk people going mad against vaccines (throughout Europe actually)

anakhro

15:02

Not that mad. The UK has one of the highest vaccine rates.

It's a vocal minority, sure.

leslie townes

we have some of that in the united states as well. it helps that the orange man is no longer able to tweet.

jeea

orange man was always good for some fun

anakhro

at the expense of others

leslie townes

i saw an unpleasant scene at a store the other day. someone was trying to get in without a mask. the people who worked at the store are not paid enough to patrol that boundary.

i wanted to kick the guy. i didn't.

it would have felt really good, though. just a solid kick. just one. no stomping, although he probably deserved that too.

anyway i'm still thinking about it.

anakhro

hard to know where people are coming from these days

Though most of the people who should not have to wear a mask will have proper documentation with them and won't put up a fight.

leslie townes

15:09

i just can't imagine what's going on in your head where you're like, i'm going to make some minimum-wage workers have the worst hour of their life. because of something i saw on television.

robjohn

@leslietownes Yeah, they lull you into a false sense of security, and then wham! You find that she has every device in the house controlled by Cortana.

leslie townes

i have a toothbrush that wants to access my wireless network. i'm not joking. i bought a toothbrush and it came with all of this networked shit.

copper.hat

the trojan toothbrush

robjohn

that could be dangerous if you hold anti-MS views. You think you're brushing your teeth and the toothbrush explodes.

copper.hat

adds new meaning to you have a bit stuck between your teeth

leslie townes

15:16

it sometimes blinks in the middle of the night because it's trying to connect. i'm never giving you the password.

copper.hat

it will figure it out eventually, how long will it take to get to 123456

robjohn

This is why we have IPv6, so that every toothbrush can have its own IP address.

leslie townes

oralb.com/en-us/why-switch is not my brand but the same idea. why would you let a toothbrush get that far into your life.

i knew a guy once who said he chose passwords starting with z because they would take longer to crack than passwords with letters from closer to the beginning of the alphabet.

copper.hat

lush3

taking about getting far into your life

robjohn

@copper.hat Ack! Squirming uncontrollably because someone has hacked your device!

leslie townes

15:19

how did you know my password? what sorcery is this

copper.hat

perhaps connect the lush3 and the toothbrush for some oral fun

robjohn

@copper.hat They did something like that with a remote tongue on Big Bang Theory

The Big Bang Theory: Kissing Machine (Clip) | TBS

►

They kept it above the belt though, probably due to censors.

Not that the writers didn't have a huge laugh about the other possibilities...

Just imagine seeing "Lucy's Lush3" on the wifi network. Find Lucy by trying to connect.

leslie townes

the people in our new neighborhood don't have any sense of fun, for naming networked devices. it's all Spectrum345734589 or whatever. no wordplay.

anakhro

I'd scream "nsfw!!!!" but i work at home now. :(((((((

leslie townes

in our old neighborhood, one of our neighbors, i never know who, had This Charming LAN as the wifi spot.

admittedly that's setting a very high bar, but i'm still very disappointed with my neighbors.

Wouter

15:44

I have a thing that confuses me, chat is better for it: i have the real function f , with property f'(x)\leq 0 , c>0. I just proved with the mean value theorem that for all x>0: f(x)\geq f(0)+cx.

copper.hat

i used to commute on amtrak to the south bay so you get to see everyone's hot spot. one was (.)(.)

Wouter

i mean instead of f'(x)\leq 0 \geq 0 **

copper.hat

use mathjax with dollar signs so it can be read easily

leslie townes

i'm still figuring out the role of c in all of this.

copper.hat

i don't c what c has to do

leslie townes

15:46

can you say more about c?

Wouter

I think they mean to say that f is increasing

copper.hat

c c j'suis un rock star

leslie townes

copper.hat is a magician with words. i am simpler and more fundamental.

Wouter

Ok i'll formulate again coz i had typos

excuse me

leslie townes

irish people have what is known as 'the gift of the gab.'

copper.hat

15:47

i do not have it, unfortunately

my powers of narration are non existent

leslie townes

which means they can run their mouths more than i can. when i run my mouth, eventually someone comes up to me and says 'excuse me, sir,' and that's the quote they'll put on my tombstone.

copper.hat

and my musical/linguistic skills equally non existent

if i do get going, my accent comes out and most cannot understand what i am saying

backing away slowly, 'that's nice joe'

Wouter

The function $f:\mathbb{R}\to\mathbb{R}$ is differentiable and has the property that: $f'(x)\geq c$ for all $x\in\mathbb{R}$.

oh doesn't tex language work

leslie townes

i like what i'm learning about c.

copper.hat

you need to start chatjax

leslie townes

15:49

i'm already thinking mean value theorem, it's not even 9 oclock. this is a good day.

copper.hat

but it looks good to me

i prefer the nice value theorem

leslie townes

copper hat has a wonderful ethnic jig dance he's going to do later. there's lots of thumping on the floor. it's peculiar to his ethnicity.

copper.hat

need some caffeine before by 9am sleep session mtg

Wouter

Now, i want to prove that $f(x)\leq f(0)+cx$ for all $x\leq 0$. But that confuses me, because when i do it with the mean value theorem, it gives me $f(x)\geq f(0)+cx$ and not the desired one.

copper.hat

a friend has a 7yo son who believes in leprechauns. i record some messages for him every now and then with my best accent

Wouter

15:51

it's because of the $x

leslie townes

so the MVT would say (f(x)-f(0))/(x-0) is something.

Wouter

x<0 that i'm confused

leslie townes

either it's wrong, which we can establish from linear functions, or it's right, which means we use the MVT. which is it?

Wouter

Well i proved that $f(x)\geq f(0)+cx$ for all $x\geq 0$, but i get the same inequality for $x\leq 0$.

so i'm messing up but am confused:P

leslie townes

we're all confused. it's the mental state of humanity.

Wouter

15:54

yeah true but i don't like it

wanna know all the dark secrets

leslie townes

i'm drawn back to that alan partridge sketch. "dere's more to ireland dan dis." unrelated.

just tossing it out there

it's not just people in bell bottoms bombing stuff. there's other things too.

copper.hat

:-)

leslie townes

so what happens if x is negative? i'm missing something here.

ok, the sign of x fucks up the inequality. hrm.

the chat definitely has smarter people than me on it. figure this out. please

Wouter

no it's all good!

thanks

jay

why does $\gamma$ on latex look so different to hand drawn gamma?

leslie townes

16:09

what do you mean? my hand drawn gammas look exactly like that.

jay

same

but people complain

leslie townes

i recommend starting fights with these people. push them. then use one hand to put their chin where you want it and hit them with the other hand.

anyway, that's what i do. it's worked so far.

i'm not in jail.

jay

i went to jail, i dont want to go back

They made me cough

Wouter

jail is where the cool people at

leslie townes

i actually don't recommend using violence against anybody. yes, there are a lot of cool people in jail. but you can also be cool without being incarcerated.

copper.hat

16:14

i am non violent unless a member of family is threatened. in which case my perspective changes.

@Wouter do you know anything about the sign of $c$?

leslie townes

a guy on my block shot me with a bb gun when i was something like 10 years old. on my father's instructions, i beat him up, bad, and after that he didn't shoot me with a bb gun anymore. i hope that i don't have to give my daughter this toxic legacy.

i'm still curious about c. is c positive?

Rajorshi Koyal

16:43

I do not know where I went wrong.

Rajorshi Koyal

16:58

Where did I go wrong?Tried a coupe of times but all in vain.Please check if possible.

Transcript for

$Mathematics$ Mathematics