ok....?

@Daminark Tis copyrighted

and I'm not allowed to join chat?

Didn't say that. Just said that sometimes it's not necessary.

@Daminark So are you taking courses throughout the summer?

yeah, but to call it trolling or to tell someone to delete helpful information is just downright rude.

If someone else is already helping, then having another person jump in can be a bit confusing.

I wouldn't call it trolling.

"Read the transcript before responding to messages"

Pretty much.

and I'm sick of people saying "im trolling" every ten seconds cause they don't like my own opinions.

I mean, if the conversation has stopped for a while and it's not obvious that it was going on, that's one thing.

That is a rule.

@BalarkaSen

@Dodsy basically, though it's not graded. We'll be giving/receiving lectures on and doing problems in 4 books

Well, it's a guideline.

@Daminark What's that called again? Surveying?

It's not a rule, but just a norm before jumping into conversations. In real life too.

Sorry, rule may have been a strong word.

Somebody maybe talking about Ingmar Bergman's movies and someone just jumps in, hears the word "movie" and says "I love Action Jackson" or something

"Don't flag behavior as uncivil unless you're sure it's actually hurting others."

That's one which people need to follow.

At the end of Titanic, the boat sinks

(I hope that's not an actual spoiler to anyone)

@Astyx ....

@Semiclassical well or unless you are personally offended and it was directed at you in which case use a custom flag.

Why did you ruin that movie for me?

@Astyx no you spoiled the IRL incident

Sorry :/

:)

At the end of Rome, Caesar dies

@Dodsy Troooolllll :P

I've recently found love in Korean movies.

Fine. In the end of Titanic, they detonate the Matrix and Darth Vedar dies.

Has anyone else been plagued with this affliction?

@Dodsy I guess it could be called surveying

lol

Korean filmmakers know how to play at your heart strings.

@Dodsy I like them too

@Balarka at least Darth Vader isn't spoiled

Closest I've been afflicted with is watching lots of no-commentary horror game playthroughs on Youtube.

At least those I've watched

I think a general rule of thumb for mods in these chats though is to not ban people every time an 'offensive' comment needs to be deleted. It's not different than in ordinary chat. We don't ban people every time irrelevant or annoying or mildly crude posts get deleted so that future readers aren't offended. I think the same needs to be true in these chats.

because idfk

@Astyx I watched "I saw the devil" , one of the best movies I've ever seen..

and "the tunnel"

@Semiclassical Interesting. What do you watch?

As in, which game playthroughs?

i mean, if mods weren't so ban-heavy then those flags would've only accomplished in removing 'offensive' content which really shouldn't bother anyone. I mean, unless it ruins the transcript.

I've tended to stick with a few specific Youtubers.

were is @TedShifrin

So, for instance, I've seen a lot of the stuff on this guy's channel: youtube.com/channel/UCrbdVuw_4Tt0zBE5Gmo4TwA

Italy @Danny

@Danny He's on vacation.

He is late for tennis

Pew pew @Dodsy

I mean, the stuff in there that's actually horror and not stuff like Guardians of the Galaxy or The Walking Dead

@Semiclassical Cool beans.

i don't tend to watch youtube much

some of it is better than others.

I mean, jump scares are effective enough.

@Danny oh, are you meeting with him?

just kiding

but they can be really cheap.

Oh haha.

Popcorn flies

you might jump a bit, but the next moment you're like "oh that was stupid."

it's hard to find a good horror movie.

But I still love them.

@Dodsy I can give you good reco

There's a lot of foreign-made games as well, and the translations are...yikes

Watched a lot of em recently

@BalarkaSen Sure, but make sure my gf will like it too.

@Astyx The best place in the world :P

@Alessandro Yeah it's really good since it's so close to France !

Plus I find that the endings rub me the wrong way a lot of the time

@Dodsy Dead Ringers ducks

As far as which ones I've seen that I actually like

Eh, not technically a horror movie. In principles, but not technically.

It's the inspiration for Little Italy in NY which is the best place so that makes it a good candidate @AlessandroCodenotti

This doesn't look bad.

I like it a lot.

David Cronenberg's artistically best film

@Astyx well played lol

Someone said horror? :D

I find filmmakers often have no creativity.

I also like Erasorhead, which I watched fairly recently

I think it all depends on what kind of horror you want. Slasher/gore/torture/exploitation? Or actual artistic horror.

I'm not a fan of exploitation stuff.

I think I mostly like ghost-type stuff.

I don't care about the genre as long as it's done right.

Like The Shining as a book was terrible.

But the movie was great.

@BalarkaSen check this out if you get a chance: rottentomatoes.com/m/akmareul_boattda

Revenge movies are the best

The more I think about, the more I think that it's ghost stories that I find most interesting.

Not sure why.

Movies about revenge or movies written as revenge?

haha movies about revenge!

Like kill bill

Lol, the latter would be rather intriguing but I also don't see it making sense

haha.

Revenge math.

There are pretty terrible ghost movies out there. Ghost genre has a terrible stereotype attached to it.

Can't argue with that.

It's true.

@Dodsy Thanks, I will.

Whenever I watch a horror movie I think "please don't be ghosts, please don't be ghosts" and then when it's not ghosts "please don't be aliens, please don't be aliens"

There are some excellent alien movies out there.

Is Kill Bill any good ?

I watched The Thing, which is a classic, a few weeks ago.

@Astyx Yeah, it's great.

There's a really good animation sequence in it.

I'll add it to my watch list

If I ever write a watch list

There's a part 1 and part 2

Revenge math would probably consist of sniping someone's conjecture

I always find movies to watch, but when the time for watching actually comes, I don't remember any of them and end up not doing anything

Hey man, you're exactly like me

@Astyx same. But I bet you saw the intouchables.

Is it that magician movie ? If so I haven't

Oh, I thought it was really popular in France.

Okay it isn't

But I still haven't

It might be, I'm not too aware :p

When I had that foreign exchange student staying with us, she wouldn't stop talking about it. She thought it was a major blockbuster,(and it probably was in France) but not many people had heard of it over here.

I see

I have to go now, see ya later (probably tomorrow in my referential)

@Astyx oh alright, cya man.

I don't watch blockbusters admittedly

I'm really sick of Ben Afleck

Oh jeremy Irons is in this?

He's great.

He got an Oscar for Dead Ringers, just on the next movie he did.

At least that's how the popular legend goes.

I guess I better start studying.

@Dodsy it is very popular in Italy though

I need to review derivative rules :/

@AlessandroCodenotti is AoC needed to construct ordinals?

@AlessandroCodenotti The Intouchables??

Oh, no wait, I was thinking of another movie

oh

:)

What movie

$f(x)=7{^2x}^{2}+x$

how do you write this

No, wait, that's the one!

@Dodsy triple exponentiation.

Do you mean the untouchables (1987) or the intouchables (2011)?

@Dodsy either {a^b}^c or a^{b^c}. a^b^c is not defined.

2011

Then yes, it's quite well known in Italy

jesus christ.

@Dodsy ... you need nested brackets.

$f(x) = 7^{{2x}^2} + x$

right

like Russian dolls

did you mean $f(x) = 7^{(2(x^2))} + x$?

wait

the + x

is on the same line as 2x

$f(x) = 7^{2x^2 + x}$?

right

@LeakyNun nope

@AlessandroCodenotti is AoC needed to prove that ordinals are well-ordered with respect to inclusion?

ohhhh

I need the ln7 too

@Dodsy yes

"$x$ is an ordinal iff it is transitive and well ordered by $\in$" is the usual definition

@AlessandroCodenotti do we need AoC to prove that, e.g. $\omega^2$ is well-ordered by $\in$?

I'm off

bye lads.

is $\mu$ a function of any linear function of the parameters $(\theta_1,\theta_2)=(\frac{\mu}{\sigma^2}, - frac{1){2\sigma^2}$

@LeakyNun I don't think so

I mean ordinals are well ordered by $\in$ by definition, so you need to show that $\omega^2$ is an ordinal, but that isn't that the order type of $\omega\cdot\omega$ with the lexicographic order?

Time to read chemistry. Ugh.

@AlessandroCodenotti alright.

how to justify to someone in highschool that the extended sine function no longer depends on right-angled triangles?

@AlessandroCodenotti

what's the extended sine function?

I mean, for example $\sin90^\circ$

@Leaky I think I remembered using the unit circle for that?

@Daminark yes

but initially when sine was introduced, it was in a right-angled triangle

then how come we can ignore the triangle now?

Well you draw the triangle on the circle, say it agrees there so continue it using that

@Abcd are you here?

@LeakyNun I had left

Tag me if something related to me @LeakyNun

@Abcd see the above

@LeakyNun What?

@Abcd essentially, since the two methods agree when the angle is acute, we use the other method to extend the sine function.

@LeakyNun didnt get you

@Abcd the unit circle method and the right-angled triangle method.

@LeakyNun WHat does this mean: "we use....function"

@Abcd we use the unit circle method to extend the sine function

what is "extending"?

"to extend the sine function" meaning "to define the other values of the function"

e.g. when the angle isn't acute

@Abcd this is maths. we do what we want.

:(

You have another function which you can rename sïn such that its restriction to acute angles is sin :P

man, inside >> outside right now.

84F outside with 64% humidity is hardly the worst weather, but just enough to make going inside feel wonderful

It's like 94F with 66% humidity here

So yeah, same

yuck

you dirty man @Balarka :P

I asked a magic 8 ball if I'd be a better mathematician than @TedShifrin and it said "don't count on it"

I'll say this for Farenheit: 100 F may not be the boiling point of water, but it's pretty much my own boiling point

37C. Yeah that's hot-ish

gdi mathematica why are you complaining

oh, there we go

@Avantgarde I have a hard time converting to Fahrenheit from Celsius

It's been 30 degrees here the past coupla days

@Dodsy I have a hard time doing the opposite.

30C is okay with me. A little warmish though

I really don't mind it.

But everyone here complains about the weather.

anything below 15 is bad :(

where? US?

if it's winter, it's too cold, if it's summer it's too hot.

Canada.

ah okay

the standard jokes for MN weather are

yeah so winters are like -20 some days

-20 is like Pluto for me :P

1) The four seasons of MN: Winter, more winter, still winter, and road construction.

2) Don't like the weather? Wait a day and it'll be different.

Oh wait, I misread your comment. I have a hard time converting from F to C as well

I use google to do that job

@Semiclassical lmfao

we all do, @BalarkaSen

My grandfather is from Britain and can easily convert between the two.

km to miles is easy for me it's just 1.6*km

but c to f is magic.

I can do c to f and vice versa, but not very fast.

I mean, I know that -40 is the same in both

It's like 1.8*c + 32

And that 32 F = 0 C.

So something like 1.8(c+40)-40

right, that makes sense.

That works too.

but eh.

just because I can say that doesn't mean I can do it quick

I know that 25 C is about room temp, but only from seeing that in lab practice enough

kelvin is easier

kelvin to celsius, you mean?

-273 c is 0 kelvin

right

yeah.

the funny thing is, if you do condensed matter physics you'll ultimately see people talk about temperature using energy units :P

by that, I mean

in thermodynamics, you typically never see $T$ by itself but rather $k_B T$ where $k_B$ is Boltzmann's constant

And that's got units of energy.

so it's not uncommon to see temperature referenced in terms of what $k_B T$ would be.

oh, know what''s interesting semi.

for the trig function graphing on the test

For instance, I think at 300 K one has $k_B T=\frac{1}{40}eV$?

it was -2sin(2x)-7

so if you hadn't have thought of that, i wouldn't know what was going on at all.

oh, nice

@Semiclassical that's sort of interesting that they do it as energy units.

ah, should be more like 290 kelvin

it's part of the whole drive in higher level physics to do everything in units where $\hbar= c = k_B=1$.

once you do that, it's natural to say "whenever I see temperature, I'll really do $k_B T$."

Do you feel that physics has progressed tremendously since Albert Einstein? Or is it mostly detail work.

Sure. The standard model is a thing now, for one

What are the areas of research that are highly funded.

Well, historically high-energy experiment has had a lot of support

the LHC being a big example of that

another big area, though, is broadly speaking condensed matter physics

which includes stuff like superconductivity.

oh, that's interesting.

Observational astronomy/physics too, I suppose?

I include "particle physics" within high-energy experiment.

certainly, yeah.

quantum computation

easily the most highly funded atm

I wonder about that. It's definitely one of the most fashionable.

But if you look at NSF funding I'm not sure how it breaks down.

I have friends who get paid absolutely ridiculous amounts by companies

What's the math equivalent of string theory?

(quantum computation is mostly a commercial thing, not really academics)

@Avantgarde What is that supposed to mean?

@danu Ah, I wasn't sure how you were framing it.

Within industry, yeah. Big money there.

Within academia, it's got some support but it's still pretty niche.

It should also be noted, though, that different research programs require different things.

Like string is a popular/ambitious school of thought, what's the counterpart in the math community?

That's pretty vague.

thought so

If you're doing high-energy experiment, the scale/costs of the experiments can be so large that the only way for them to proceed is via big research collaborations and gvmt support.

String theory is interesting, but I don't feel like I know or understand it enough.

Everything I know about physics is either from watching documentaries or watching Neil Degrasse Tyson talk about it.

@dodsy A pretty good rule of thumb is: If you think you know what string theory is, statistically speaking you're probably wrong.

@Dodsy Then you probably have no idea about any kind of physics :p

@Semiclassical so I might actually know it?

:p

@Danu Well, I mean, I took high school physics, so algebra based.

there's a long way to go in physics before you reach string theory @Dodsy

String theory is just ugly math

Let me put it like this. While I don't know the math of GR, I at least know the relevant concepts.

I can't say the same for string theory.

I'd be suspicious of any judgment of the elegance of string theory, though, by anyone who hasn't studied it. That includes myself.

@Semiclassical GR being?

general relativity

oh right.

"mass curves spacetime, and objects move subject to gravity according to that curvature."

I feel like that's one of those topics that is terribly explained as well. Most people who think they know GR or SR usually don't understand it.

True.

I know the math of SR pretty well. 4-vectors and the like.

I know a lot of the concepts as well. But I wouldn't call myself an afficianado.

Hi

I know stuff about Lorentzian metrics

Hi @Akiva

The thing I always find weird about SR is this

I've heard people say things like "time always goes fast when we're ______, well that's relativity for you"

Suppose I'm standing still and I see a spherical planet way off in the distance.

Actually, doesn't relativity only slow time down...?

Now I get into a spaceship and move towards that object at close to the speed of light, passing it at the end rather than flying into it.

Slow or fast only makes sense relative to some other clock

As I'm passing it at the end, I look at it again. What will I see?

An oval

a stretched sphere

idk.

@BalarkaSen Relative to an inertial reference frame

@AkivaWeinberger that sounds right.

heh. That's the usual guess for people who know a bit of special relativity---length contraction business.

@Semiclassical You've talked about this puzzle not too long ago, right?

Yeah, I'm fond of it.

@AkivaW That's right, then, yes.

hm...

However, what that doesn't take into account is that not all of the light which reaches your ship will have left the planet's surface at the same time.

let me think then.

Some of the light rays will have had to travel farther than other rays in order to reach the ship at that instant.

This isn't something you'll be able to guess, I suspect.

haha alright tell me then semi.

Would it look the same

now I'm imagining a swiss cheese planet

The outline you'll see will still be spherical.

woo

You won't see the same sphere as you would at rest---there will be abberation effects---but the overall outline is still spherical.

What about depth perception?

shrug

I'm guessing it would also tell you you're looking at a sphere

I think your eyes are far enough from the planet that depth perception doesn't matter?

But I honestly don't know.

just with the stuff on the surface pulled back

@Semiclassical You physicist.

lol

I can never find a good animation on Youtube for this, alas.

what kind of aberration effects.

I thought I saw an online app or something for it

spherical abberation, basically

but i'm quoting stuff from memory on this.

so it would look like swiss cheese

see minute 5 of this: youtube.com/watch?v=JQnHTKZBTI4

oh I love this narrator.

oh

hahah

so it's like a colour thing

there's a lot of things, tbh

if you start from the beginning they include various effects one by one

th.physik.uni-frankfurt.de/~scherer/qmd/mpegs/…

yeah, that's not bad.

There's a linking of this stuff to some pretty good math, but I've never really tried to follow it

John Baez has a pretty good discussion of it here: math.ucr.edu/home/baez/physics/Relativity/SR/penrose.html

including, at the very end, the math I was alluding to

Baez has a nice website

Did Balarka leave? Something homology-y happened in the news, though I'm not sure how much I understood

There were headlines saying we discovered 11-dimensional structures in the brain. Which doesn't make sense. And apparently that's not actually what happened

ping him

@BalarkaSen

lol what is that. Who covered the news? Fox?

So the brain is modeled by a directed graph, and subsets of the vertices and edges make up what are known as "directed cliques"

I'm here

So a clique is basically a tetrahedron in it, a bunch of nodes each connected to each other

Ok

and a directed clique is the same but there are arrows now, and they're oriented the way simplices are in homology

mhm

like $(v_0,\dots,v_n)$, and $i<j$ implies arrows from $v_i$ to $v_j$

So what they do with that, for whatever reason, is make something called a "flag space" out of it.

So basically, they interpret the cliques as vertices of simplices, and make a simplicial complex

so for every clique you make a simplex, yeah?

Ok. How are these connected?

A what dimensional simplex?

Oh 0

If there's a clique with 12 neurons (that's a lot for a neural network, apparently!), our flag space is 11 dimensional