#serious-discussion

1 messages · Page 479 of 1

surreal sapphire
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i think it should be notfallmöhre

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we don't really do -

pale orchid
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for foreign words, sometimes

surreal sapphire
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als it inherits caps from the noun Möhre

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Notfallmöhre

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Möhre

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nouns are capitalized

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beginning of sentences KEK

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headings start in caps as well

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also in english?

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i think so, yes

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i am sure

frigid lark
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ah thank you. Is it worth to learn tikz

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I have some html5 canvas experience, should be easy to learn it I guess. tikz-graphs fit so nicely to the text.

limber thunder
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plus there's fun stuff you can do with for loops

frigid lark
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nice nice, gonna learn

maiden bear
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I'd like to know the context behind this

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about carrots

surreal sapphire
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Szene 1: Die Möhre betritt den Raum. In einem Sessel wartend der Sellerie. Ungeahnt derer, vor dem Fenster schemenhaft für die Zuschauer zu erkennen: die Gurke.

devout nacelle
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Scene 1: The....for the....the

pale orchid
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in front of

devout nacelle
surreal sapphire
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Sellerie is celery

devout nacelle
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Oh

surreal sapphire
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thats sad i tried to use vegetable names that are different in english

devout nacelle
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Sessel?

surreal sapphire
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like Möhre isnt common, Karotte is more common

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which is carrot

devout nacelle
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Ah

surreal sapphire
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Sessel is armchair KEK

devout nacelle
pale orchid
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i don't understand the sentence structure of the celery sentence

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i would've used erwartet

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oder wartend + sein; wartend, ...

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idk

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no verb = scary

surreal sapphire
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hmm

devout nacelle
surreal sapphire
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i dont enough linguistics to explain

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but its the same in english

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maybe its a stylistic device

pale orchid
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i would buy that, sure

surreal sapphire
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this is common in scene descriptions for theatre

pale orchid
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for poetic effect

surreal sapphire
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(which this was supposed to sound like)

pale orchid
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that's the impression i got

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big words from someone that just failed a safety instruction, but yeah

surreal sapphire
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i bet more people failed

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cant you just retake?

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imagine failing and not being able to blame it on the german language

pale orchid
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yeah it can be retaken as many times as you want

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and indeed, native speakers failed it lol

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i took it twice and got 39 both times opencry

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then i gave up

surreal sapphire
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lol

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tbf admin probably just needs some proof you took it

pale orchid
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watched a fucking 51 minute video and then spent 2 hrs going through the 10 questions

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no, they want you to send the certificate with a digital signature

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and you can only get the certificate if you pass

surreal sapphire
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what kind of safety stuff is this

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how to act in case of fire?

devout nacelle
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What kind of test is this?

surreal sapphire
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amokläufe blobsweat

devout nacelle
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Don't you already know German?

pale orchid
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brandfall, sure, but also how to deal with dangerous substances and what to do if there's an accident

surreal sapphire
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ah ok, you deal with dangerous things

pale orchid
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brief shoutout to different kinds of fire extinguishers, how to use ladders and defibrillators, etc

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i don't

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i deal with a laptop

devout nacelle
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Very dangerous

pale orchid
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but other people in the institute do

surreal sapphire
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they can explode

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well ok

devout nacelle
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Edd can explode solving those big matrices

surreal sapphire
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my security briefing was "sign here"

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at my first job in industry we skipped the security stuff

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and there was an accident

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one of my coworkers lost a hand

pale orchid
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i could brute force it, too. unlimited tries, and there are 10 questions only. multiple choice, you can select as many as you want from 4 options

surreal sapphire
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and our boss got in big, big, big trouble

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because he couldnt prove there was a security briefing

devout nacelle
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That sounds awful

surreal sapphire
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it is

pale orchid
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so something like $\left(\sum_{n=1}^4 \binom{4}{n}\right)^{10}$ options

fathom swallowBOT
pale orchid
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yeah i think they're being more careful since a mofo forgot to put on safety glasses during a laser welding thing

surreal sapphire
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thats finite, which concludes the proof

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ye, once something happens they make everything way more strict

deep mango
pale orchid
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i do sigproc stuff, but the applications are very industry-oriented

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we coop with some institutes that do stuff like inspect railroad tracks, weld stuff, use radar to detect buried mines, and other fun (c.f. super dangerous) stuff

surreal sapphire
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pinpointing your location

neat lintel
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wait what do you work in?

pale orchid
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sigproc

neat lintel
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what's that?

pale orchid
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signal processing

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i sit in front of a computer and go "lmao correlations"

neat lintel
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lmao

analog salmon
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I love how operator calculus always looks like bad math, but works out

neat lintel
neat lintel
shy pollen
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ij wasted 3k on a raincoat

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why am i this stupid

chilly wigeon
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Is there a channel for analysis

deep mango
sonic ether
neat lintel
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did they find it?

honest veldt
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Wtf new analysis channels?

mint patio
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I thought I liked power series

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now seeing this stuff for ODEs makes me head go hyperthonk

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looks like a lot of work for such an ugly solution

cold needle
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wait till you see frobenius

limber thunder
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tbh these are outdated methods

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people in like the 18th or 19th century cared about solving ODE by power series

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nowadays you just approximate a solution by runge-kutta or smth

mint patio
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why is y'' - y = 0 the classic example

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because you get sine cosine out which is satisfying ig

cold needle
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and matches the other methods we have

ancient flame
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geometric calculus is cool af

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like $\prod_a^b f(x)^{dx}$ is the geometric integral

fathom swallowBOT
ancient flame
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when I learned about this I think I came

deep mango
cold needle
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STOP BEING HORNY FOR MATH

fair mural
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bruh

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how do you even respond to this

honest veldt
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You don't

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Just let it sink in silently

ancient flame
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LOL

swift sinew
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What’s the intuition for a staircase with n stairs from (0,0) to (1,1) not having a limiting length equal to sqrt(2)?

untold sapphire
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i mean have you tried working out the length manually in the case n = 1, 2, 3

swift sinew
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I mean obviously the length is gonna 2 for all n but why does it differ from the expected limit if you look at “the limit” geometrically?

untold sapphire
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ok, i see

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imo calling it the "limit" geometrically is up for debate as jagged things and smooth things have big differences between them, i mean you know the old question "How long is the coastline of britain"

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it depends on the scale at which you measure it! do you post a marker every mile, every ten miles, etc

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or if you looked at a picture of the stock market graph from today and asked "what's the total cumulative change in the value of the stock, counting all ups and downs, all highs and lows"

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if you looked at the change every five minutes and added them all up you'd get a different answer than if you looked at the change every hour

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the "limit" you're talking about of the staircases is IMO an infinitely jagged thing and we shouldn't expect it to resemble a smooth thing

swift sinew
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Ah that makes sense. Though if you decided to define the limit in some fashion similar to being contained in an arbitrarily small rectangle around the straight line, would the difference then be that the staircase has some “measure” (in a loose sense) that’s different than the straight line?

modern bramble
untold sapphire
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hmm ok i have come up with an answer

deep mango
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You could make the zig zags go more steeply and then the length would be even longer

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You could make the length infinite

untold sapphire
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my idea is that the length of a curve c is like

deep mango
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Sorry triangle inequality

untold sapphire
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$\int_x T(x,f(x), f'(x)) dx$

fathom swallowBOT
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diligentClerk

untold sapphire
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where $T$ is a function of both $x, y and dy/dx$

fathom swallowBOT
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diligentClerk

untold sapphire
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so we should only expect length to be well behaved with regards to the limit of a sequence of functions $f_n\to f$ if $f_n\to f$ not just "pointwise" but also in terms of the derivative we also have $f'_n(x)\to f'(x)$

fathom swallowBOT
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diligentClerk

untold sapphire
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I think for complex analytic functions you get this automatically but not in our example

swift sinew
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I’m having a bit of a hard time understanding why the length of a curve is some int{T(x,f,f’)}

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I guess I get it, but I have a hard time seeing why x and f’ also need to be arguments for T. Isn’t just f sufficient

untold sapphire
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as we go from $x$ to $x+\Delta x$, if we assume that the curve is locally linear then the length is roughly given by the pythagorean theorem, i.e. $\sqrt{(\Delta x)^2 + (\Delta y)^2}$

fathom swallowBOT
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diligentClerk

swift sinew
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Gotcha gotcha

untold sapphire
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and i'm using the approximation $\Delta y \approx \Delta x \times (dy/dx)$

fathom swallowBOT
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diligentClerk

untold sapphire
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so it simplifies to this $\int \sqrt{ 1 + (f'(x))^2} dx$

fathom swallowBOT
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diligentClerk

untold sapphire
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which is what i mean we should only expect length to behave well wrt limits of functions if we also have $f'_n \to f'$ because $f'$ is what actually appears in the definition of length

fathom swallowBOT
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diligentClerk

swift sinew
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That makes sense, does this seem like something that might have an already-existing formalization?

untold sapphire
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uhhh i don't really know enough analysis to answer that but it I think that we should have the precise theorem that if $f_n \to f$ (where $f_n, f$ are continuous and differentiable) on the interval $[a,b]$ and so does $f'_n\to f$ on the same interval, then the lengths of the $f_n$ should converge to the length of $f$

fathom swallowBOT
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diligentClerk

swift sinew
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I feel like that implication is in the opposite direction than what would answer my question, but I guess it’s satisfying to the extent that for the staircase, the antecedent doesn’t hold so I shouldn’t expect the consequent to hold

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Sorry if that was worded confusingly

untold sapphire
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nah i get what you mean

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it's not a direct explanation, it's more just showing that the obvious theorem you would write down doesn't imply that this is true

swift sinew
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Not much new there outside of what you’ve explained here

untold sapphire
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mm nice

honest veldt
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the only dog person in this discord, this is shocking stuff

mint patio
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why do we care about phase portraits and trajectories and whatnot

deep mango
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to understand what happens when the equation can't be solved

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at first you just do them for linear equations

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but later you do them for nonlinear equations (in particular, you often look at their linearizations around equilibrium points)

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and the phase portraits can tell you a lot about solutions without you knowing how to actually solve for them

mint patio
deep mango
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(e.g. the poincare bendixson theorem is a big theorem in this regard)

deep mango
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"topologically" isn't really a technical term here

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i guess the better word is "qualitatively"

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so, for example, maybe you don't know what solutions are, but using the phase portrait you see that all the solutions are converging to some stable equilibrium

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like a sink

mint patio
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so important things to consider would be the limiting behavior of solutions, holes/regions where they blow up, etc?

deep mango
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yep

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and sure, just looking at a picture isn't a proof

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but the picture can tell you what to do to get a proof

mint patio
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And solutions x(t), y(t) only differ up to constant right?

deep mango
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uhm for linear inhomogeneous equations

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or

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idk

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that might not always be true

mint patio
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This is what I have

deep mango
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no that's not true usually

mint patio
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So one ODE/system can have multiple solutions?

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Ignoring constants

deep mango
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well

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no

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or

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at time t_0, you give an initial condition

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the initial condition is just the point where you start

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the ODEs tell you how to move from that point

mint patio
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ok that's what I meant, mb. the only difference between different trajectories is different ICs

deep mango
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yeah

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but the trajectories don't need to be like

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translates of one another

mint patio
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oh

deep mango
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they could do totally different stuff

ancient flame
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imagine math papers using comic sans

swift sinew
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Isn’t that not necessarily true for non-convex sets or am I misremembering

deep mango
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(the important thing is, if you pick 2 points, then either the trajectories they are on are disjoint, or they are the same trajectory - as long as time goes forward and backward)

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this is just cause if the two trajectories ever collided

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then from then on, the derivatives along both are the same

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and by the fundamental theorem of calculus, if two functions have the same derivative and are the same at a point, they are the same function.

mint patio
# deep mango translates of one another

I'm confused, aren't we multiplying constants most of the time anyways? Why is"don't need to be translations of one another" something important to mention? Aren't they usually not translations of each other?

swift sinew
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Like if you have this system over that kidney-bean shaped set, multiple functions can satisfy this system and have the same value c_1 but different values c_2
(Feel free to ignore this if it’s obtrusive to the convo)

deep mango
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and that's not always true

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(if it were true, one curve would be a translation of the other)

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but that's not what you meant so it's fine

deep mango
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i get what you mean but

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like to me a solution is only valid on a connected interval

mint patio
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Oh wait

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hm

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I'm testing it with x = e^t, y = e^(-t) and different constants and they are translations of each other

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let me try other functions

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when I subtract them I just get 0

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oh

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idiot

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ok nvm I am not getting constantw

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yeah I'm so confused

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how are solutions supposed to be different besides with constants like this

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any ode's gonna have a unique fundamental set of solutions right?

shy pollen
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everyone is mac at me

mint patio
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so the only way we can get different trajectories is with different linear combinations of the fundamental set

shy pollen
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but i just blocked my friend bc i made fun of her career path

mint patio
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what am I misunderstanding?

sick burrow
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Alg top is weird

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Like this feels like the next big step up in abstraction for me

crystal stone
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eh

sick burrow
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Because it's like my first real encounter with the whole approach of turning one thing into another thing and then studying the properties of that new thing

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Like even in my other advanced math classes, I'm still studying the properties of a thing in "its own language" so to speak

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Idk. Like I'm getting it, but it feels harder than anything else I've done.

swift sinew
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Can we get a “how to get help” mentions over time graph, possibly normalized to number of users?

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It really feels like we’re saying it extremely often

uneven steppe
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^

swift sinew
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And a ban count tbh holy crap

leaden torrent
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theres no easy way to get those numbers without running a bot

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if you want it to be measured over time that is

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mniip could probably easily add it to bot, but im not sure what that'd help with.

sick burrow
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What are the most common reasons for a ban

leaden torrent
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if you just want a total ban count, we have 3147 banned users

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this is different from the total number of bans though

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since bans from about 2 years ago have all been thrown out

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(when we shifted over to the ticket system, we undid a lot of old bans)

leaden torrent
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by far.

sick burrow
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Besides that

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Like bans of actual users

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Not bots

leaden torrent
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just trolling i guess

primal crater
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got 2 users banned due to rude behaviour

leaden torrent
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if youve only sent 8 messages on the server, all in #chill , and 3 of them are racist or transphobic, we typically wont give a second chance

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we're a little more lenient (read: mutes with strong warnings instead of bans) if the user has contributed to the server in another way

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since perhaps they just said whatever message out of ignorance

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but thats less common

uneven steppe
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Period

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Anyway need advice on something

sick burrow
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I wonder what the ratio is of the different types of bigotry for banned users

leaden torrent
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in my anecdotal experience, transphobia is the most common

sick burrow
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That's what I've noticed too but I'm obviously biased to notice it more

leaden torrent
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also a lot of people in help channels calling others idiots/r*rds/autistic or whatever

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which i guess you could classify as bigotry

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thats gotten less common recently though

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like, even before the new help channels, it was on the decline

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which is nice

uneven steppe
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He was 13 anyway and annoying

sick burrow
leaden torrent
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both

uneven steppe
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Wait anyway I teach a recitation at 9:00 tomorrow but I’m not tired bc I took a nap should I just stay up and study all night lmao

leaden torrent
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youll feel tired eventually.

sick burrow
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Honestly this server is impressively well moderated

leaden torrent
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no it isnt

sick burrow
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Ok there are some annoying emote spammers that should be banned or at least muted

light needle
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if it were well moderated how am i not banned

sick burrow
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Spamming girlboss and whatnot

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But besides that

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Idk I just feel like "public discord math server" are not the words that make me think "good community"

light needle
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yeah to be fair for a public discord server this is like

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surprisingly good

crystal stone
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no it isnt

light needle
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we could have been like, the physics server

crystal stone
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what are they like, sir john

swift sinew
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How’s that server doing btw

light needle
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A lot of racism and stuff in the upper ranks from what i understand

sick burrow
light needle
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I mean public servers are like

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a menace to humanity usually

crystal stone
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why do you care if you get honorable or not

light needle
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ya know

sick burrow
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Don't interfere

sick burrow
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(I'm meming)

crystal stone
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Ah I c

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Some people really overly value that stuff

sick burrow
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And just die

light needle
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you already are in one

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already dead sorry

sick burrow
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No like a larger more mainstream and toxic one

light needle
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probably joining a gamin community will do that

leaden torrent
#

WHAT IF I WAS WRONG AND NO ONE CARED TO MENTION
WHAT IF IT WAS TRUE AND ALL WE THOUGHT WAS RIGHT WAS WRONG

light needle
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is this from a song?

sick burrow
# leaden torrent WHAT IF I WAS WRONG AND NO ONE CARED TO MENTION WHAT IF IT WAS TRUE AND ALL WE T...

I've already seen old discussions of this so I know the majority of you will disagree and claim that mutate is weak. Lots of gas lighting trolls up in here. I pretty much just play Arena but I win the majority of my games. The only thing I consistently lose to is mutate decks or one of several super combo decks where suddenly I'm hit for 50+ damage in 1 turn. Mutate literally beats anything that doesn't play faster or isn't more or less an antimutate deck. So then your only options are mutate deck or antimutate deck. I can't even think of another set of cards that comes close to buffing like mutate does.For anyone who disagrees, please tell me how YOU would beat a mutate deck without saying "cancel deck" that's not playing. That's nobody playing.
p.s. Whatever you assume of my deck construction it doesn't change the fact that mutate is the only deck type that I struggle against. In Arena I'll quit discard/ mill matches cus I just don't want to deal with it.
TLDR Most deck types are useless trash against Mutate decks.

#

Ok what is the best copypasta

leaden torrent
leaden torrent
# light needle is this from a song?

Manchester Orchestra's official music video for 'Simple Math'. Click to listen to Manchester Orchestra on Spotify: http://smarturl.it/MancOSpotify?IQid=MancOrchSM

As featured on Simple Math. Click to buy the track or album via
iTunes: http://smarturl.it/SimpleMath?IQid=MancOrchSM
Google Play: http://smarturl.it/SimpleMathGplay?IQid=MancOrchSM
A...

▶ Play video
sick burrow
leaden torrent
#

its an incredible pasta since its 100% genuine

pale orchid
#

namington is poorly moderated

leaden torrent
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and he actually thought itd make him look better

sick burrow
#

The best pasta are always the ones originally written unironically

light needle
sick burrow
#

It brings me great joy that in addition to be a raging bigoted asshole, he's also just shit at mtg

inner finch
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mm oo mmm ooo mmmm oooo

compact tartan
#

yea

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now I've become one

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the vicious cycle continues

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nah that's just being an asshole

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is this happening on here or elsewhere?

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that should not be happening in here

distant vortex
#

If you make a typo, that's one thing. But if you don't know how to spell a word and keep getting it wrong, I'm sure the intention is to just tell you so you learn how to spell it.

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It's not cocky.

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I know what incident you are referring to, and you misspelt it the same way more than once.

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No, you think it's cocky for them to call you out for disappearing for 20 minutes while they are waiting in the channel to help. That's not cocky.

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she

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After she said that, it still took you 25 more minutes to actually reply

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So I don't think it matters what she said, you weren't there

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Lol

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You are way too sensitive, but okay, I'm not interested in arguing with you. Just letting you know that from reading the exchange, I don't think she did anything wrong.

neat lintel
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Hold on.

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Somebody clue me into this?

distant vortex
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Okay, next time tell her you will wait for someone else to help you rather than continuing to let her help you and then once you get what you need, you come here to complain.

blazing pawn
#

This is so sad

distant vortex
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No one is responsible for what other people have said to you in the past. Nothing she said is very egregious, so it really shouldn't have upset you this much.

neat lintel
#

That's a good analogy.

distant vortex
#

Please stop pinging me when you reply

blazing pawn
#

This is so silly

distant vortex
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I'm done here since I think you are unreasonable

neat lintel
#

Strike, we all have bad days, but that isn't the way one should cope up.

blazing pawn
#

Getting your spelling corrected is not a valid reason to rant here for 20 minutes

distant vortex
#

No, the problem is that you think someone correcting you is them being cocky, when it's just them correcting you.

neat lintel
#

Heard about displacement defense mechanism?

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You're frustrated, so since you're frustrated you take it all out on somebody.

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On everyone?

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Then who?

blazing pawn
#

Please stop ranting here

neat lintel
#

There's a better way to channelize all your frustration.

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this chat belongs in #vent

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Hope you could take that into account.

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Hmm???

distant vortex
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My time to vent: I am in shambles that I was blocked by Read.

maiden bear
neat lintel
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That's sad.

frail lagoon
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dino

neat lintel
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Hang on.

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He edited a message.

maiden bear
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LOL what is that whole convo

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i saw the help channel earlier

distant vortex
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Don't laugh at my despair

maiden bear
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didnt expect it to escalate like this

neat lintel
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Let this one slide.

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And i never saw the help channel.

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Oh.
I thought "help channel" to be a vent channel or something.

maiden bear
#

HAHA

neat lintel
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Didn't catch you there.
Discord servers who offer to help someone?

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I've seen many vent channels. Maybe they do.

maiden bear
frail lagoon
reef carbon
#

what happened here, god damn

toxic schooner
neat lintel
thorn brook
reef carbon
#

nice vaguepost btw

neat lintel
#

toki mfking doki

shy pollen
neat lintel
#

Toki is amazing. Toki is cool and trusted and talks and is very active

paper peak
#

hello

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can anyone help me on a simple matrix problem?

neat lintel
swift sinew
#

Why do the discussion channels feel post-apocalyptic? Feels like it’s just a whole lot of wreckage

leaden torrent
#

early morning hours

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they always get like this

neat lintel
#

thank you.

maiden bear
neat lintel
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however, you got no excuse

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mniip said yes

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i mean, we discourage venting here, so it's best to vent on private server instead

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also i'm not man

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but ok

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yes, why are you still asking?

maiden bear
#

read their about me catThink

deep mango
#

in shambles

maiden bear
#

in shambles

honest veldt
#

in sandles

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wait

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That's not how you spell that

maiden bear
#

in sandals

honest veldt
#

day ruined

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Thanks

distant vortex
#

I don't think anyone wants that

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Rate My Helper

fair mural
#

helpers pretty much don’t even respond to pings lol

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i imagine that they all have pings disabled

primal crater
#

ppl take the helpers role for the 'color' only

fair mural
#

lol

primal crater
#

I got blue so I don't need green

fair mural
#

this blue is pretty cool though

primal crater
#

cyan's my fav tho

#

🌈

distant vortex
#

They set everyone's nickname to a random number

fair mural
#

make me grahams number

primal crater
#

if a custom bot does it then no

primal crater
fair mural
#

oof

leaden torrent
#

that is literally what we did

#

this april fools

fair mural
#

wow

leaden torrent
#

next one probably wont be nickname related

fair mural
#

why

primal crater
leaden torrent
#

because itd be the same joke twice?

fair mural
#

beaned

primal crater
#

this time make it a prime number

leaden torrent
#

how long

#

ok.

primal crater
#

make everyone a MOD

#

a fake one

fair mural
#

@primal crater assigning a role to 70k people

primal crater
#

a bot will do it in seconds

maiden bear
#

depends on where its hosted ig

compact tartan
toxic schooner
#

how did i miss that

analog salmon
#

I didn't realize I was gonna have to learn so much german for alg. geo

#

first hilbert's nullstellensatz, now Krull's hauptidealsatz

#

wtf is this

maiden bear
#

LOL

honest veldt
#

How do you even say that, my guy

maiden bear
#

i mean the first one is just hilberts root theorem translated i guess

#

the second one idk

#

my english maths vocab is not sufficient there

fair mural
#

i love math but i wouldn’t learn another language for it lol

analog salmon
#

I think it's "principal ideal theorem"

maiden bear
#

yeah the thing with ideal is always

#

its several meanings

#

in english and german

analog salmon
#

or maybe it was in their grad school

#

had to learn russian or french or something

wild lantern
#

I think that used to be a thing at several places.

#

My school has a language req

#

I can't remember if it's just the math dept or not tho

mint patio
#

I do not like systems of differential equations

#

For the sole reason of I do not understand drawings

frigid lark
#

I like euler method, cus its simple to solve those equations. But I didnt bother yet with the analysis approach

ancient flame
mint patio
#

I'm an engineering major KEK

#

I think we would do better with STEM major moment

ancient flame
#

lol true

maiden bear
#

drawings slap

#

even though i cant draw for shit

ancient flame
#

lol

simple cliff
#

calculus is the best

#

🙂

fair mural
#

it is pretty cool

simple cliff
#

quatum phyics in interesting got to learn calculus to understand it tho

fair mural
#

i haven’t actually gotten to calculus 3 yet but i’ve looked over it a bit and it looks really cool

simple cliff
#

im in cal 1 going for engineering

#

aerospace engineerin going to a college close to get regular classes done

#

hope i can transfer to georgia tech

untold sapphire
#

satz just means statement (theorem)

#

hauptsatz means something like, principal theorem or main theorem

tawny spoke
#

haup-on-deez-natz

leaden torrent
#

if only calculus was sufficient for quantum stuff

#

maybe people would stop overhyping it so much

river linden
#

relevant xkcd:

leaden torrent
#

id swap special relativity and magnets tbh

#

you can visualize the underlying mechanics behind special relativity quite easy even without an understanding of the mathematics that births it

#

good luck doing that with magnets

#

why do magnets need a north and south pole??? why arent there poleless magnets?

limber thunder
#

I feel old

wild lantern
#

On the bright side I suppose faygo soda is fairly cheap.

simple cliff
#

?

leaden torrent
#

really what

toxic schooner
# simple cliff really

calc is not sufficient for quantum mech lol
nami was saying if only it was, maybe then it wont have been so popular

timid spindle
#

quantum mech is overrated.
You sussy baka, Nyah

#

can't even solve classical problems 😐
You sussy baka, Nyah

inner finch
#

You sussy baka, Nyah

toxic schooner
cold needle
#

what

#

bro i didn't even know i was gonna do math until literally maybe 3 years ago max

#

how do ppl find out about this shit so soon yo

timid spindle
toxic schooner
toxic schooner
primal crater
#

too advanced for this channel

inner finch
#

lol

compact tartan
leaden torrent
#

idk man, multivar doesnt help me understand why they work

#

it helps me compute shit about them sure

neat lintel
deep mango
#

I want to do quantie!!!!!

neat lintel
turbid epoch
#

math makes me feel very self confident but then I realize I'll die broke and lonely /s

toxic schooner
primal crater
#

for my indian friends

turbid epoch
#

I'm getting out of here

devout nacelle
#

Bruh

turbid epoch
#

This video gave me blood pressure.

primal crater
#

ok

raven vector
round umbra
#

Lol

neat lintel
#

fuck fb

neat lintel
toxic schooner
neat lintel
#

do you guys know of any good website to practice trigonometry, which has a choice of practicing basic things or advanced. just annoyed of looking at worksheets which don't even have answer keys

distant vortex
#

Khan academy?

neat lintel
distant vortex
#

I don't know any

neat lintel
distant vortex
#

Read got rid of the Helper role zztlol

#

I would tell her that's based, but she blocked me blob_cry2

neat lintel
neat lintel
#

aops

#

i forgor

neat lintel
neat lintel
neat lintel
#

he deserves it

#

ask mods for helper role

devout nacelle
#

Helper role is literally punishment

sterile hare
neat lintel
#

i agree with janman

neat lintel
devout nacelle
fair mural
#

someone getting helper role is just giving them 500 pings a day

neat lintel
#

1984 pings

neat lintel
surreal sapphire
#

helper role has rights now though

fair mural
#

like what

surreal sapphire
#

close question channels

sterile hare
#

need a hint on help-20 pls

hollow vale
#

anybody know if this paper is legit? Looks like it proves the remaining unknown Moore graph does not exist, the one with degree 57 and diameter 2. If so the wikipedia page for moore graph needs to be updated, as it's no longer an open problem. https://arxiv.org/abs/2010.13443

devout nacelle
#

Have you checked if this paper has been submitted/accepted for publication anywhere?

neat lintel
neat lintel
fair mural
#

you have role pings disabled don’t you @neat lintel

fair mural
#

how many pings do you get a day

neat lintel
#

...

#

ignorance is bliss

#

i dunno, ask Google 😎

#

fuck google

ancient flame
#

is there any way to think about $\int \frac{f(x)}{dx}$?

fathom swallowBOT
icy forge
mortal igloo
#

Yeah, you're dividing a function by a differential form to get section of the tangent bundle, but you can't integrate that kind of thing

ancient flame
#

alright thanks

subtle mortar
#

anyone mind answering this question for my data project?
How Much Phone Screen Time Do You Have per Day? (In Minutes)
and
How Much Computer Screen Time Do You Have per Day? (In Minutes)

hollow vale
#

Thanks ShatteredSunlight, yeah it seems like the author is legit

shy pollen
#

fortnite

swift sinew
#

This might be heresy, but is there anyway to get a role where the help channels are inaccessible/not visible?

sick burrow
#

You can mute them

#

Then if you minimize the category it hides everything

leaden skiff
leaden torrent
#

0.2103495009000539124852931855 minutes (how long it takes me to turn my alarm off in the morning and turn it back on at night, measured using an atomic clock)
3.419 * 10⁵² minutes (measured using observations from a collection of telescopes around the earth's orbit, time dilation effects unaccounted for, accuracy subject to atmospheric effects)

#

you're welcome

cold needle
#

thanks

timid spindle
limber perch
#

not the atmospheric effects

real sigil
#

hey i wanna talk maths

#

i got a question or two

raven vector
#

Dont ask to ask

#

Just ask

shy pollen
#

no don’t ask pls

real sigil
#

i will, i am sorry, they left me no other choice, i want my family back ...

#

anyways

#

lets see

#

when we say complex numbers

#

do we mean the unreal numbers, or real numbers + imaginary ones

raven vector
#

Only imaginary numbers

real sigil
#

so this image is wrong right?

raven vector
#

Ig

real sigil
#

what we would we call the set that contains real + complex numbers

#

would it be computable numbers?

neat lintel
honest veldt
#

You'd call it the complex numbers

neat lintel
#

so you could say real number + imaginary

raven vector
neat lintel
#

yea

raven vector
#

it has a real ‘part’ and imaginary part

neat lintel
#

where a is the real component and bi is the imaginary one

honest veldt
#

Imaginary numbers are just complex with a 0 real part

#

They're all in c

#

C*

raven vector
#

Complex = imaginary

real sigil
#

oh that make sense

neat lintel
#

don't think so

#

1 + i isn't imaginary is it?

honest veldt
#

It's complex

neat lintel
#

yea

real sigil
honest veldt
#

Complex and imaginary aren't the same

#

Imaginary is a part of complex numbers

real sigil
#

based on what i understood, complex can be non real, while imaginary has to be non real

neat lintel
#

yea?

honest veldt
#

yeah, that checks out

raven vector
surreal sapphire
#

0 is imaginary probably

honest veldt
#

Yeah, in a+bi, you say the real part is a and the imaginary part is b

surreal sapphire
#

it is also real

raven vector
surreal sapphire
#

ultimately it doesnt matter though, i have never encountered a reason to consider purely imaginary numbers

honest veldt
#

Ah gotcha

neat lintel
neat lintel
surreal sapphire
#

the imaginary numbers are just another copy of R inside C

raven vector
#

Qm, qft

real sigil
#

is there a name for the set that contains algebric + non algebric numbers

neat lintel
#

yea it's used as a complex number

real sigil
#

or would we just go with complex

surreal sapphire
#

every (complex) number is algebraic or not algebraic, so ...

real sigil
#

oh i guess

#

is there a non complex number?

surreal sapphire
#

number isnt really a well defined term

real sigil
#

then, infinity?

surreal sapphire
#

no

raven vector
#

Infinity is not a number

real sigil
#

what even makes a number?

#

is it the "value"

#

because imaginary numbers dont really have that known concept of values

#

yet they are considered numbers

surreal sapphire
#

well

#

i would define a number to be an element of a skew field

#

numbers are things you can add, subtract, multiply, divide (with an exception of division by 0)

real sigil
#

make sense

#

also, lets say a graph, with a curve, we made sure that each Y has no more than one X

#

does that mean that this graph has a function ?

leaden torrent
#

it means that the curve is the graph of some function

#

(in absence of any other disqualifying information at least)

real sigil
#

damn, theres like an infinit possibilities of graphs, didnt expect each of them has an functional expression

compact tartan
#

"function" doesn't mean "formula"

#

some functions don't have formulas

real sigil
#

oh for real?

#

lol

#

didnt know that

#

so basically, if i see a graph, that doesnt mean it has a formula?

#

wow

river linden
#

yeah just draw some squiggly line, that squiggly line doesn't have a formula that's exactly equal to it at all points

#

though you can find formulae that approximate any graph arbitrarily well @real sigil

real sigil
#

yeah i guess you can aproximate a formula for every curve you see

river linden
#

you can actually prove that you can for reasonable curves, ie. all the ones you could draw without picking up the pen

real sigil
#

it sounds quite weird to me how you can formulate every curve

river linden
#

well, you can approximate any function with a polynomial as well as you want, so that lets you formulate any curve as close as you want

#

i can't really explain in detail since you don't know calculus

real sigil
#

sadly

river linden
#

the main idea is that you can approximate any function with a piecewise linear function

#

basically a bunch of small connected lines

#

by making the lines small enough it approaches the function

#

then you can approximate the piecewise linear function by a polynomial as well as you want, so overall you're approximating any function arbitrarily well by a polynomial

real sigil
#

so we transform the curve into tiny lines?

#

like old people used to do to circles in order to calculate their perimeter

river linden
#

yeah exactly

real sigil
#

in that case, is it easy to make a formula for those lines?

river linden
#

well it depends on your definition of "formula", you can get a piecewise function that describes those lines

#

it would look something like
$$
f(x) = \begin{cases}
m_1x + b_1 &\text{ if } x \in I_1 \
m_2x + b_2 &\text{ if } x \in I_2 \
\vdots \
m_nx + b_n &\text{ if } x \in I_n \
\end{cases}
$$

fathom swallowBOT
real sigil
#

in this case we have divided the curve into 3 lines right?

#

oh wait nvm

river linden
#

i've named the intervals $I_1, \dots, I_n$

fathom swallowBOT
river linden
#

so we basically cut the function into a lot of tiny bits that are very close to being linear

real sigil
#

oh nice

#

that makes it really clear now

river linden
#

yeah thats one of the main ideas in calculus

#

if you zoom in closely something is linear

#

then if you take lots of those linear guys and add them together you get the function

real sigil
#

this cant possibly contain all of the graph, but will sure makes it alot easier to understand

compact tartan
#

you're not capturing the function exactly

#

rather forming a sequence of approxmations

#

that can approximate the function arbitrarily well

real sigil
#

yeah its sad how this is the best thing we can do

#

ill try to invent a computer that can make formulas

#

gimme a good 15 yaers

compact tartan
#

well

real sigil
#

and aloooooot of patience

compact tartan
#

forget functions

#

there are real numbers that don't have formulas

#

in fact "most" of them don't

real sigil
#

dude....

#

how come ive never realised that

#

lmfaoo

compact tartan
#

the argument is really simple

river linden
#

computable numbers sotrue

compact tartan
#

there's only a countable number of formulas, but uncountably many real numbers

real sigil
#

yeah theres like a ton of nonfinite numbers with no formulas to represent them whatsoever

#

infanct its an infinit amount of numbers

river linden
#

do you know what countable/uncountable means?

real sigil
#

i guess?

#

countable means it has some sort of representation

#

like sqrt x or cos x or something

river linden
#

countable means you can enumerate them all, the natural numbers are countable since 1,2,3,... enumerates them

#

uncountable means you can't

#

the natural numbers, integers and rational numbers are all countable

real sigil
#

oh so we are talking about decimal numbers and non decimal

river linden
#

but the real numbers are not

#

no

#

well

compact tartan
#

words in a finite alphabet are countable

#

you can enumerate them by listing first all 1-letter words, then all 2-letter words, etc

#

every word will be eventually listed

river linden
#

the way I like to think about it is every computer program can be represented as a finite list of zeros and ones, therefor they are countable

#

and since the real numbers are uncountable there must be real numbers that cannot be calculated by programs

real sigil
#

what are examples of something uncountable

compact tartan
#

subsets of N

#

there's no way to list all subsets of natural numbers

real sigil
#

it pains me to say that i dont cognize what that is

river linden
compact tartan
#

"equiv" is a strong word

#

but yea

real sigil
#

is countable and uncountable a state of one single number or a set?

compact tartan
#

it is a property of a set

real sigil
#

in that case, no set is actually countable

#

right?

#

because they have equally infinit amount of numbers

river linden
real sigil
#

well maybe not equally

compact tartan
#

"uncountable" is in a rather precise sense a "larger" way for a set to be infinite

#

the set of natural numbers, while infinite, is not very "large"

real sigil
#

||damn, its 2021 and people are coming up with things bigger than infinity ||

#

yeah

compact tartan
#

when were cardinal hierarchies invented? gotta be 1910s

river linden
#

two infinite sets are said to have the same size if you can map one to the other and back again in a 1-1 fashion

compact tartan
#

the idea of uncountable sets probably comes from 1700s

real sigil
#

the infinity provided in the amount of numbers of the natural set
should be smaller than the
infinity provided in the amount of numbers of the rational set considering it has the same numbers + more

#

am i collecting you this way?

compact tartan
#

actually maybe 1800s

compact tartan
real sigil
#

how come lol

compact tartan
#

they're actually the same "size"

real sigil
#

becuase inf = inf

#

yeah it makes sense

#

but still kind of paradoctic

compact tartan
#

there's as many natural numbers as there are even numbers

#

and as there are rationals

#

but less than there are real numbers

#

but there's as many real numbers as there are complex numbers

real sigil
#

this is weird lol

river linden
#

they all make sense once you see the proofs/reasoning

real sigil
#

its like we are no using the same constitution in different comparisons

compact tartan
#

it is a finicky notion

real sigil
compact tartan
#

hard to say "what changes exactly"

real sigil
#

cant we still do a 1-1 fashion in between real and natural?

river linden
#

no

real sigil
#

we have like, a batallion of naturall numbers

#

still not enough?

river linden
#

too many, that's the problem

compact tartan
#

we don't have enough natural numbers

river linden
#

you can always find a real number that isn't on the list

compact tartan
#

so maybe to motivate this a little

#

there's this thing called the pigeonhole principle

real sigil
river linden
#

where if you have n+1 pigeons and n holes then two of the pigeons have to get comfy stareFlushed

compact tartan
#

if you have a function f : X -> Y, where X and Y are finite sets, with, say, m and n elements respectively

#

if f is surjective, then necessarily m <= n

#

if f is injective, then necessarily m >= n

#

if m <= n, then there exists a surjective f, and if m >= n then there exists an injective f

#

this is why we use surjections and injections to talk about "sizes" of sets

#

because these generalize beyond the finite case

#

albeit you lose some things

#

e.g. an infinite set can inject into a proper subset of itself

river linden
#

surjective means every y has an x with f(x) = y

compact tartan
#

but this is why, generally, when we ask, is X a larger set than Y, we are really talking about whether there exist injections/surjections between X and Y

river linden
#

and injective means f maps every x to a unique y

real sigil
#

so if we represent X with natural numbers, and Y with real numbers, we would have F (x) = y being an injective function

#

?

compact tartan
#

we could come up with an injective function yes

river linden
#

you can form an injection from N -> R because the size of N is less then R

compact tartan
#

but we wouldn't be able to come up with a surjective one

real sigil
compact tartan
#

yes you can

river linden
#

you can

compact tartan
#

this is like

#

bog standard intro to proof topic

real sigil
#

this "function" we are using, can it be any type of function?

river linden
#

you represent the rationals in a square then you take the diagonals to get a list [r1,r2,...] of all the rationals

#

since any rational number is somewhere in the square, say at (x,y) you have the rational number (x/y) then eventually it is in our list

#

since we made a list you can make a function from a natural number to that element in the list f(n) = r_n

#

bing bang there's your surjection

real sigil
#

so basically, this shows how clear it is that Q contains N

compact tartan
#

"contains" doesn't mean much when it comes to size

river linden
#

it shows we can find a map from N to Q that "hits" every rational number

compact tartan
#

this is precisely what I meant when I said

[8:48 PM] mniip: e.g. an infinite set can inject into a proper subset of itself

real sigil
#

so this is a surjection

compact tartan
#

sure

real sigil
#

do we not have a surjection when it comes to even numbers To whole numbers?

river linden
#

we do

real sigil
#

but still he said theres as many natural numbers as there are even numbers

real sigil
river linden
#

yeah, so we have a surjection

#

whole numbers? you mean integers? [0, -1, 1, ...]

compact tartan
#

surjection means more-or-equal

#

injection means less-or-equal

real sigil
#

no i meant, naturals, sorry

#

surjections means more or equal

compact tartan
#

you can build a surjection both ways

#

so they're more-or-equal than eachother

#

i.e. equal

river linden
#

yeah so if we show N is more or equal to Q (the rationals) then they must be the same "size" since N is in Q so N is also less then or equal

real sigil
#

this equal thing is the problem, i see

#

"equal"

river linden
#

no its not a problem if you show a >= b and b <= a then a = b

#

"equal" refers to our invented notion of equal size

real sigil
#

but we already know that N=/= Q

river linden
#

you're confusing set equality with cardinality equality

#

N is not Q but their size is the same

#

since you can map N -> Q and Q -> N in a 1-1 fashion

real sigil
river linden
#

well if you had >= and != then you get >

#

(greater equal, and not equal implies greater then)

real sigil
#

its kind of null how we go back to = from >= and <=

river linden
#

do you know what a bijection is?

#

its basically an invertible function

#

ie. surjective and injective

real sigil
#

like, the amount of X = Y

river linden
#

if f : A -> B is bijective then A and B have the same size

#

this is our definition

real sigil
#

yeah thats it

river linden
#

for finite sets it makes sense, since {a,b,c} and {1,2,3} can have the mapping f(a) = 1 ... etc

#

now for infinite sets it gets tricky, but this is the definition of size we're using

#

listing the integers as [0, -1, 1, -2, 2, ...] gives us a function from N to Z that's bijective

#

therefor size(N) = size(Z) by our definition

river linden
real sigil
#

as either >= or <= will deliver us back to = which bijection

river linden
#

not either, you need both

real sigil
#

yeah...

river linden
#

wdym "infinite set-contained function bijective"

real sigil
#

i mean, the function where X and y are infinite set

#

sets

river linden
#

ah

#

1 sec lemme show you the proof that R is uncountable

#

meaning it is not bijective with N

#

basically, suppose f : N -> R is bijective

#

we can represent each real number as an infinite decimal (rationals become 0.400000000000...)

#

then we flip every digit in the diagonal creating a new number

#

since we flipped the first digit it is not equal to the first number, since we flipped the second digit it is not equal to the second number...

#

our new real number cannot be in the set

#

by construction

#

therefor f is not bijective and so R is uncountable

#

https://youtu.be/elvOZm0d4H0 is a good video if my explanation is bad

Sometimes infinity is even bigger than you think... Dr James Grime explains with a little help from Georg Cantor.
More links & stuff in full description below ↓↓↓

Minute Physics video on this topic http://www.youtube.com/watch?v=A-QoutHCu4o (somewhat more fast-paced... but we did film ours BEFORE his was uploaded, so similarities are coincident...

▶ Play video
real sigil
#

can we prove also that Q is asbolutely bigger than N?

river linden
#

no, card(Q) = card(N) but card(R) > card(N)

#

since we can find a bijection from N -> Q by taking the diagonals of

real sigil
#

given that q=n, then r>q

river linden
#

yes

real sigil
#

oh makes sense

#

so R is the bigger one, whilst the ones below it are equally equal to each other

river linden
#

yeah

real sigil
#

damn thats an interesting way to validate it

river linden
#

actually it gets hairy, there might be infinities between N and R

real sigil
#

wdym infinities

river linden
#

that was a famous problem in math

#

like, a set A with card(A) > card(N) but card(A) < card(R)

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In mathematics, the continuum hypothesis (abbreviated CH) is a hypothesis about the possible sizes of infinite sets. It states:

There is no set whose cardinality is strictly between that of the integers and the real numbers.
In Zermelo–Fraenkel set theory with the axiom of choice (ZFC), this is equivalent to the following equation in aleph numb...

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it turns out it's independent, ie. there might or might not but either way we'll never know since our axioms are not strong enough

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or: you can assume its true or its false and it doesn't effect anything

real sigil
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i think the safest choice is to assume bijection

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if its not right then its not wrong

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no?

river linden
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i'm not a logician so idk ¯_(ツ)_/¯

real sigil
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yeah i get it

river linden
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there are also sets larger then R

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theres a theorem that the set of all subsets P(A) is always larger then A

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so the set of all sets of real numbers is a bigger infinity then R

real sigil
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what???

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the set of all sets?

river linden
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the set of subsets

real sigil
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like the sum of whats inside R

river linden
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P(N) = {{1}, {1,2}, {1}, {1,3,4,9}, ...}

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the set of subsets

real sigil
river linden
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in fact P(N) = R which kind of makes sense if you consider decimal expansions as lists of natruals

real sigil
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is it equal or bigger?

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i think its =

leaden torrent
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is what

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|P(A)| > |A|

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this is a strict inequality

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youll never have |P(A)| = |A|

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in the finite case, it turns out that |P(A)| = 2^|A|

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this isnt hard to justify with elementary combinatorics.

real sigil
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i think so, yeah

leaden torrent
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(though formally speaking, such a justification is probably circular... but meh)

river linden
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proof by thinking: for each element of A we could include it or not include it in the subset, that's 2 possibilities for each element of A so 2^n possible subsets

real sigil
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i mean i guess you can justify it as long as |P(A)| = 2^|A|

river linden
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well, that doesn't work in the infinite case

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basically another contradicty boi

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also why tf does wikipedia use xi for an element of A stare

river linden
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suppose $f : A \to P(A)$ is surjective, and consider $$B = {a : a \notin f(a)}.$$ there must exist an $a \in A$ with $f(a) = B$ since $f$ is surjective, but this causes a contradiction since $a \in B = f(a)$ contradicting the construction of $B$ which implies $a\notin f(a)$

fathom swallowBOT
real sigil
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surjection usually cause thus kind of paradox

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thats why we take bijection for infinit sets

leaden torrent
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bijections are just 2 directional surjections

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(assuming the axiom of choice)

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(its phrased using injections, but you can just flip the arrows of an injection to get a surjection)

river linden
river linden
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I could have assumed f was bijective as well since bijective implies surjective

shy pollen
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obviously lol

neat lintel
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What are some interesting/cool facts or properties of Lagrange Polynomials?

swift sinew
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They were not discovered by Lagrange but instead by Edward Waring

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They can be used to give very high order numerical approximations of integrals (see Gaussian Quadrature)

crystal stream
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Is it just me or can they be derived by using cramer's rule on a vandermonde matrix system

neat lintel
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That sounds very interesting, thanks!

neat lintel
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A matrix of matrices

elfin thicket
elfin thicket
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we now just invented “infinite matrix composition” cool name huh?

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M[(a(b(c(d(e……….if there were infinite letters in the alphabet)))……)]

toxic schooner
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i present to u, matrix cat

pale orchid
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how about matrix cat transposed

turbid epoch
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really tho, can we have a matrix in a matrix?

toxic schooner
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but i dont want to

simple raven
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And there exists a lot of rings of matrices

turbid epoch
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I'll... pretend I understand this for now.

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I just started abstract algebra.

simple raven
toxic schooner