« first day (3061 days earlier)      last day (2256 days later) » 

22:00
@Ted so that means I need a 1/5 because that's the probability one of an incorrect answer. Just need to figure out how it fits
Well, Demonark, you might end up doing some serious computations in your thesis work. More and more of that in pure math.
So I got a laptop with an i5, 2.9GHz dual core, 16GB RAM, and 512GB SSD
How many 1/5's, @CaptainAmerica?
@Daminark yeah they're actually quite light now, and they're durable af
22:00
@ÍgjøgnumMeg Real IT departments are running only fortran on machines from the 60s
Hi @loch
one of the main reasons I got one (I cycle a lot so I want something that aint gonna fall apart in my rucksack)
@Alessandro rofl
Durability is nice. And again, I might end up getting a desktop of some variety so if I have a laptop I might be able to sacrifice a bit of power
so far I have 0.8^10 * 0.2^5 * ?
OK, @CaptainAmerica. Now what?
lenovo screens can resist a cat's teeth. The same cannot be said of the frame around the screen, from personal experience
22:02
lol the f
LOL, @Alessandro.
well you said I need to consider the whole thing so...15, maybe?
@TedShifrin the kinds of computations that a laptop can do or more heavy stuff?
@CaptainAmerica: Stop talking and think.
22:03
My cat, on the verge of starvation (a full 4 hours from breakfast and with dry food available) knows how to grab my attention
The problems come in an order, @CaptainAmerica. Whatever you do has to take that into account somehow.
I dunno. Some stuff in algebra and number theory can be reasonably intense, not to mention differential equations stuff (which you're less likely to do, I realize).
yes, @Alessandro, definitely on the verge of starvation.
number theory
I've heard Grobner bases are a thing but know nothing of them. I would suspect based on extremely limited knowledge that modular forms are also useful. I guess also based on the fact that lmfdb.org is a thing
22:05
My former classmates who took computational algebra this semester insist that they are very useful
Yeah, yeah, I know.
Oops, I meant to edit. Oh well.
Höw tö ännöy ä Germän with a few simple döts
hähä
uh oh
22:06
But if I put my accents backwards in Italian or French, ...
summoned
Here comes the German!
da dütsche
Mathein has come to smïte us all
Definitely too much summoning occurs in here.
22:07
I just type the e. I can't be bothered to google the umlauted version of letters.
Math chat is yugioh confirmed
@TedShifrin eh, a lot of people in Italy don't really know when to use è vs é. For the other letters is easier, they only have one kind of accent
I'm very careful to get accents right in French, @Alessandro :P
I'm not OCD, but I am finicky when it comes to language.
French is way worse than Italian with accents
hï ëvërÿönë
22:08
German is boring — only umlauts.
@Mathein obviously been typing that since you entered chat
We only have them on the last letter of few words ending with a vowel
Factorial or nah?
Just put an accent every other letter in French and you basically have it
@TedShifrin Lest you forget the scharfes S.
22:09
å
like pastà, @Alessandro :D
@Mathei Does this make sense?
@TedShifrin grrr
ancient Greek is interesting with accents that shift when you inflect the word
nah, Demonark, not nearly that many
22:09
Báguette
@AlessandroCodenotti yes
that word has none, zum Beispiel
í ý á ó are Faroese accents!
I always write Weierstraß even in English
@MatheinBoulomenos Latin has the macron system, but those accents are all unwritten in actual literature
22:10
There are some words like baratro which is really read as bàratro while the standard for Italian would be baràtro, but you just have to know which words have an unusual accent if it's in the middle of the word
Me too, @Mathein, but you folks told me that \S turned into ss some years ago.
I think I need a factorial
@Ted only in certain situations do you use ß
@TedShifrin it didn't! only in some words like daß->dass
Nice thing about Spanish is that there's just one accent and it's for indicating emphasis
22:11
after long vowels and diphthongs I believe
dass just looks horrid to me, @Mathein.
@MatheinBoulomenos Thanks. I'm starting to appreciate those arguments when used judiciously
Unless you're in Switzerland where they don't use ß at all
@AlessandroCodenotti meaning, you do them and a geometer judges you?
Demonark: Why do you need the accent in sì? I mean ...
22:12
@ÍgjøgnumMeg The last reform should be long vowels want ß and short vowels want ss. So wissen and weiß...
@Alessandro exactlee
@Alessandro: I thought that was how it works, sorta.
And the very weird essen and aß
the a is long there
I think it also stays ss in any case where you have compounding words, but this is a hazy memory at best.
22:13
solange man kein aas isst, ist alles gut
That is, where you have an ending s next to an initial s.
Why is $\operatorname{tr} (\operatorname{adj} A \frac{\mathrm{d} A}{\mathrm{d} A}) = (\operatorname{adj} A)^\top$ in Jacobi's formula?
0.8^10*0.2^5*5!
:P
what are those weird dots between the numbers
22:14
@MatheinBoulomenos lol I had to look that up
@TedShifrin you actually hold it for a second, si and sí are pronounced differently
@Mathein die AAS*
No, @CaptainAmerica. You couldn't explain that to us even if you tried.
22:15
Is it possible to have two point $x,y\in X$, $X$ a scheme, with $x\in\bar{y}$ and $y\in\bar{x}$? It doesn't happen for affine schemes but I don't see it in general since not every pair of points is contained in an affine patch
I hate probability and all of its spawn
Attempts at correct answers are ones you can explain logically.
Get over that.
Probability is fun :(
Scratch the factorial - it makes no sense
@AlessandroCodenotti nope, it's impossible, because schemes are $T_0$
22:17
@MatheinBoulomenos Oh, nice, that's a relief
I was afraid for a moment that my mental image of schemes was completely wrong
@CaptainAmerica16 here's a sales pitch. Does combinatorics seem fun to you?
Not really
I liked the traveling man thing tho
and the bridge thing
I finally taught probability (having never taken it) my last year on the faculty. I wished I'd started teaching it 30 years ago.
That's graph theory, not combinatorics, CaptainAmerica.
22:20
Oh, ok. Then I don't like combinit-stiff
Combinatorics: the mathematical field of counting committees with various leadership structures.
I don't know if this is a good picture, but I like to think of schemes as being stratified by $x\leq y \iff x\in\bar{y}$, so that taking closure "goes downstairs". The clear example would be $\mathrm{Spec}\Bbb C[x,y]$ with $3$ levels, the generic point on top, $(f(x,y))$ in the middle and $(x-a,y-b)$ in the bottom. This also helps me think about generic points as being close to many points downstairs
Puts Fargle back on the differential geometry committee
@Alessandro in general in a topological space, the relation $x \mapsto y : \Leftrightarrow y \in \overline{\{x\}}$ (read as $x$ specializes to $y$) is reflexive and transitive and it is anti-symmetric iff the space is $T_0$.
@TedShifrin You are insistent. Woe be unto me that you are also right.
22:22
You can be blunt, @Fargle. I'm obnoxious.
Hopefully wherever I end up on the faculty is chill with people teaching classes outside their specialty. a good opportunity to learn things I otherwise wouldn't
@AlessandroCodenotti I'd say it's a good picture to have in mind
It used to bug me that I had colleagues who taught only first two semesters of calculus, undergraduate algebra, and graduate algebra. Nothing else.
@TedShifrin If you'd believe it, I really do just forget sometimes that I want to learn things. It happens with about every bit of math I'm interested in, about once a week.
@CaptainAmerica16 I like the book Combinatorics and Graph Theory by Harris, Hirst, and Mossinghoff. It covers combinatorics, graph theory, and the infinitary versions of these.
22:24
If I found you obnoxious, I likely wouldn't come to the math chat anymore, given that you're room owner. :P
I wonder if I've chased a few people away.
Rip, sounds like it gets repetitive. I feel like a nice thing to do is to teach a "Topics in X" that can be whatever you want
I miss anon and Pedro and Daniel F and robjohn.
"Topics in arithmetic" (using Serre)
@JasperLoy I just can't see myself ever getting into that stuff.
22:26
Demonark: I found it more frustrating teaching grad courses, because generally grad students just sit there like bumps on logs and don't participate. So I did a large variety of undergrad courses. I taught graduate complex several times, graduate diff geo a bunch of times, a few advanced grad courses, but didn't do as much variety there because I didn't teach that many grad courses.
@TedShifrin I think they are probably busy with life.
What is this four-letter word to which you refer, @Jasper?
@Ted I participate more in my grad courses than I did during my undergrad courses
Different teaching styles over there, @Mathein, and you're far from the usual undergrad.
I don't participate in any of my classes
22:28
@Daminark There are plenty of those in Bonn, but almost all of them are too advanced for me...
@CaptainAmerica16 I think that as you know more math in future, you might grow to like some topics which you think you hate now. After all, many topics are related, and you will see the relations later on in the grand synthesis, the meaning of everything.
That's probably because I hate school tho
I did teach grad diff geo one year and after the first quarter all the students were undergrads. They were all very talented. Not a one finished a Ph.D. in math, though. One Ph.D. in econ, one lawyer, one theologist. Oh, I take it back. One guy did do a Ph.D. in geometric PDE. Very gifted.
Apart from geometric group theory, which I'm taking
I guess I should say, why does $\operatorname{tr}(A \frac{\mathrm{d}B}{\mathrm{d}B}) = A^\top$?
22:29
@JasperLoy Probably. Math is very vast, I think I come across a new subject every day.
@CaptainAmerica16 I sympathize in that HS math can be woefully boring. But be careful that you do not set a bad precedent for your future work---participation is often key, either for understanding or just for getting in the good graces of your instructor.
That makes absolutely no sense, @user76284.
@Fargle Is it bad that I don't like my teachers that much either.
It's OK, @CaptainAmerica. You don't like us, either.
True, true
22:30
@TedShifrin I guess there are other users you may not miss because you didn't meet them, like Jonas Teuwen, Old John, and Theo Buehler. But when I was here long ago I talked a lot to them.
I'm trying to derive the special case of Jacob's formula from the general case. I suspect I'm messing up my indices.
Oh, I remember Old John, @Jasper. We talked numerous times.
@CaptainAmerica16 Not necessarily. I was lucky to have one really good HS math teacher for three years---not everyone is so fortunate.
My teacher just says "good job" and then messages my parents my grades.
@user76284: If you know about expansion by cofactors, then it drops out immediately.
22:32
@CaptainAmerica16 I think if you can find the latest schedules of the Cambridge mathematical tripos, their undergrad syllabus, you will see the depth and breadth of the math covered there in the three year course. I like it because you can see all the subtopics there and how many weeks they plan to devote to teaching each subtopic. Very detailed syllabus.
@JasperLoy I was looking at syllabuses for a few colleges recently. So many of them just list remedial classes. At least in my area. Plus they were state colleges.
@CaptainAmerica: That sounds only like a community college, and even they get through multivariable calc and diff eq.
Be careful what you call a "state college."
@CaptainAmerica16 I actually have no idea now why some teachers can write such detailed testimonials for their students. When I was a teacher for a while long ago, I just couldn't know that much about each individual student, because there were so many students in a class, and you don't spend very much personal time with each of them.
I don't know. Maybe they were.
rolls 11+$\pi/6$ eyes
22:34
I participated in some classes more than others. I have some weird habits. Before I used to be way more impatient and would often see where a proof was going halfway through so I'd try to push things along. I started doing it less because if it was too fast, people would just ask questions and my efforts would all be for naught
Demonark: Sometimes the smartest kids need to curtail their class participation a bit.
That's how I was back in the day - then I found out people hate "know-it-alls"
Depends how the "know-it-all" acts.
I just said facts and ignored the teacher. She didn't like me and I reciprocated.
I am not a know-it-all, but everywhere I go, I usually don't get along well with most people.
22:36
My high school physics teacher hated me, but I don't think the students did. He couldn't understand or explain anything correctly, and so I spent a lot of time politely trying to explain things so that the rest of the class could learn something.
It was very sad, actually. He was a nice guy, but was dreadfully unqualified to teach the course.
I'm a know-it-all. It's fun when I actually do.
LOL, @Fargle.
One thing I do now a bit which hopefully helps is, in a class where I kinda have an idea what's going on, is asking a question about a confusion I had that didn't immediately come to mind the first time I thought about something
I had students who thought they knew it all and actually knew relatively little. They were difficult.
22:37
Oh once in HS my classmates asked me if I could teach math instead
My physics teacher has a master's degree surprisingly, but he's incredibly boring.
@TedShifrin I say again that you may not have liked me if you had taught me. :P
Boringness is not related to qualification, @CaptainAmerica, but an incompetent exciting teacher isn't worth much.
@Fargle: I would hope that I would have pushed you to improve.
@TedShifrin I zone out.
@CaptainAmerica: Based on your behavior in here and your descriptions of stuff at home, you definitely have some maturing to do ...
22:39
@TedShifrin Possibly. Life's strange enough without speculative hypotheticals.
LOL, @Fargle.
Yeah, I guess you could say that.
@TedShifrin I think Captain is very well-behaved.
Thank you, Jasper.
I didn't say he was ill-behaved.
But he is careless and impatient and often doesn't listen.
And I spend a lot of time talking to @CaptainAmerica, so it's not that I dislike him. I want him to improve.
I have been watching youtube videos on British parliamentary sessions. Very entertaining, their sense of humour and the way they speak, especially the speaker John Bercow.
I'm trying, it's hard to listen when your being yelled at.
I mean my parents.
22:41
Oh, OK.
@ÍgjøgnumMeg Yes, I see you know him too!
@Jasper I am from the UK
@ÍgjøgnumMeg Yes, it is very sad that you are still dealing with the Brexit chaos.
unfortunately the government here is more or less useless
@Jasper I'm planning a move to Germany early next year; hopefully it isn't ruined by the Brexit shambles
lol, Brexit
Not funny, but a tad rediculous.
But I can't say much from the U.S.
22:43
Commander-in-Chief Tronald Dump
alas
we are all at the mercy of those democratically elected to lead us
A day may come when British shenanigans will overshadow ours
I can't even vote yet, I was forced into this.
It's OK, 2020 elections is coming.
22:45
"Democratically elected" is very much in question in the US, @ÍgjøgnumMeg.
@Daminark They were so close with Brexit, but then you elected Trump and won the worst political decision of the year contest
My hopes aren't very high, to say the least.
Very important for you to take voting seriously when you can, @CaptainAmerica.
@Ted right, there's not much in the way of democracy here either unfortunately
Yes, of course.
22:46
I just asked a question on main if you want to think about some (ugly) algebraic topology
All I know about democracy is that it is spelled like Democrates which is pronounced like Socrates.
And there is also Hippocrates and maybe a whole bunch of other -ates.
I'm just going to send in the program. I think I'll at least get an 80%.
@Alessandro that adjective makes me sad
U G L Y
U aint got no alibi
22:48
you ugly
Stop thinking about such things and instead think about why $\mathbb{Z}^2$ doesn't embed into $\pi_1(\Sigma_2)$
I also watched the video of the 40 year old woman attacking another woman on the New York subway, crazy video...
What's $\Sigma_2$?
22:49
Genus 2 surface
21
Q: Is the fundamental group of every subset of $\mathbb{R}^2$ torsion free?

DineshIt seems that the fundamental group of any subset of $\mathbb{R}^2$ will not have an element of finite order. Though the $3$-dimensional version is an open problem I couldn't immediately see why it is true in the $2$-dimensional case. Please shed some light on this.

apparently open
It's probably one of my favorite random AT problems at the moment
@PaulPlummer Ah, I wish I had seen that question before asking. The chances it has been closed in the last 2 years are rather slim I'd say
@CaptainAmerica16 How far are you into the Spivak book?
Well it was asked 7 years ago
But probably still open
22:51
What spurred this question? $\mathbb{RP}^2$ not embedding in $\mathbb{R}^3$?
@PaulPlummer Oh, right, I was looking at the last edit date
@Daminark yup
I know Hatcher has a question about the fundamental group of the immersion of the Klein bottle in $\Bbb R^3$. Does he have one about the Steiner surface in $\Bbb R^3$ (the immersion of $\Bbb RP^2$)?
I wonder what the sales of the Hatcher book is like given that the PDF is free.
Although I guess it could be there are not finite fundamental groups but still open in general if there are groups with torsion @AlessandroCodenotti
I also wonder how often the print book is updated.
22:54
@PaulPlummer That'd be a strange situation but it's possible
My print books have barely been updated (through no lack of my trying). I finally got the multivariable book to get a second, mostly corrected printing. The linear algebra book got a second edition. ... The diff geo text is better, cuz I can update it whenever I want, and I have done so.
@JasperLoy semi chapter two. there were some set-backs
Changing topic but I think amenable groups are very cool @Paul
You can claim you're doing group theory while secretely doing functional analysis, isn't that great?
Well, you can do functional analysis on topological groups!
I don't really know much about them, probably because of the secretly doing functional analysis part
22:59
@Daminark $\pi_1(\Sigma_2)$ is hyperbolic and thus doesn't contain $\Bbb Z^2$. Is there an easier way than the general theorems?
How do you see it's hyperbolic?
$\Sigma_2$ admits a metric with negative curvature

« first day (3061 days earlier)      last day (2256 days later) »