ℝolliℵg M∀th Thr∑a∂

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i know there are at least a couple mathematicians in the building. do mathematicians have anything cool to talk about? would be fun to hear about what research ppl are doing, or did in past lives, what courses people are taking or teaching, books we're reading, problems we're stuck on etc

i'm in my last year of undergrad program in pure math right now, currently taking general & alebraic topology (with a total madman who looks like this http://upload.wikimedia.org/wikipedia/commons/thumb/2/25/Daniel_Wise.jpg/220px-Daniel_Wise.jpg), real/functional analysis, and probability. kind of toying with the idea of pursuing grad school. i've taken a couple grad courses so far & they've gone down pretty smoothly, and there are a lot of opportunities to teach math at CEGEP (2 year mandatory pre-university program) and a masters degree is the only requirement. buuuut idk. currently applying for funding to do some research in geometry & topology with a postdoc this upcoming summer. will be spending this weekend trying to understand automorphism groups of covering spaces ^_^

flopson, Friday, 8 November 2013 18:39 (six years ago) link

We could discuss whether there is a satisfying proof for the Nilsson Conjecture.

Aimless, Friday, 8 November 2013 18:43 (six years ago) link

my own contribution: why does well-being look like this?

durianlychee (imago), Friday, 8 November 2013 18:44 (six years ago) link

xp never heard of it!

flopson, Friday, 8 November 2013 18:44 (six years ago) link

viz 1 is the loneliest number

Aimless, Friday, 8 November 2013 18:46 (six years ago) link

oh lol -_-

flopson, Friday, 8 November 2013 18:47 (six years ago) link

exactly

Aimless, Friday, 8 November 2013 18:50 (six years ago) link

i am a dormant mathematician

ciderpress, Friday, 8 November 2013 18:54 (six years ago) link

xp now you have ammunition for chatting up a mathematrix at your next conference

Aimless, Friday, 8 November 2013 18:54 (six years ago) link

i teach math

the late great, Friday, 8 November 2013 20:42 (six years ago) link

cool! how is it?

flopson, Friday, 8 November 2013 20:43 (six years ago) link

high school?

flopson, Friday, 8 November 2013 20:44 (six years ago) link

yes. prealgebra through AP calculus. it never fails to surprise me how much easier it is to teach "hard math" than it is to teach "easy math"

the late great, Friday, 8 November 2013 20:55 (six years ago) link

i'm teaching logic right now, to the least academically prepared students i've ever taught (it's not a huge difference, but it's significant), and that seems to be otm.

the extra complement of math that people generally take to get into a university, even if it stops right at or just before calculus, does seem to make a huge difference in terms of experience, comfort, confidence, mastery of working with forms and symbols.

j., Friday, 8 November 2013 20:58 (six years ago) link

How are we supposed to search for this thread title?

Somebody pointed out recently that the Notices of the AMS are online and free which is great for people like me who are not in academia anymore and don't get a paper copy. Been meaning to read through the article on Beethoven's Metronome: http://www.ams.org/notices/201309/rnoti-p1146.pdf

Also recently bought a copy of Best Writing on Mathematics 2012 which is very nice and pitched at a similar level, the article on Math and Music was very interesting, written by a guy who is both a practicing musician and research mathematician.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:07 (six years ago) link

mathematical dorks should be able to remember 98225

Nilmar (Nilmar Honorato da Silva), Saturday, 9 November 2013 21:08 (six years ago) link

thats an elegant number

Nilmar (Nilmar Honorato da Silva), Saturday, 9 November 2013 21:09 (six years ago) link

Yes!
225 is square of 15. (Which you can remember as fact in itself or as exemplar of (10 + x)^2 = 100 + 20x + x^2.
98 is multiple of 7 and figures in the decimal expansion of 1/7 if you think about it.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:13 (six years ago) link

you are ridic

bored of Canada (Stevie D(eux)), Saturday, 9 November 2013 21:15 (six years ago) link

Let's see if I can do this:
100 = 2 mod 7 so 100^3 = 8 mod 7, 100^3 =10^6 = 1 mod 7 so 7 should repeat with 6 digits
1/7 = 7/49 = 14/98 = .14 * 100/98 = .14 * 1 /(1.0 - 0.02) = .14 * ( 1.0 + .02 + .0004 + ...) = .14285(6+1)..

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:23 (six years ago) link

currently participating in a seminar on homotopy type theory and learning the rudiments of algebraic topology. been spending time with v/a Theory and Applications of Categories reprints.

lollercoaster of rove (s.clover), Saturday, 9 November 2013 21:27 (six years ago) link

Really? Where?

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:28 (six years ago) link

the seminar? at the cuny grad center http://nylogic.org/homotopy-type-theory-reading-group

didn't realize that someone else on the board would have an interest in this!

lollercoaster of rove (s.clover), Saturday, 9 November 2013 21:30 (six years ago) link

Are you enrolled in any kind of graduate program at CUNY or elsewhere? What about the other people in the seminar?

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:34 (six years ago) link

the seminar is open to the public, like lots of cuny things actually. i'd say its only about 30% people with any current relation to NYU, grad students included. v/a former students/phds, as well as just a cross-section of ppl currently just employed but with a math background, as well as maybe students at other campuses.

lollercoaster of rove (s.clover), Saturday, 9 November 2013 21:37 (six years ago) link

we're meeting in the eves biweekly to make it feasible for people who work

lollercoaster of rove (s.clover), Saturday, 9 November 2013 21:37 (six years ago) link

Thanks. By NYU I assume you mean CUNY or CCNY, although there are probably people from NYU there too.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:39 (six years ago) link

Also how long does it go for: two hours,

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 21:41 (six years ago) link

oh yes by nyu i meant cuny. goes about 1.5 hrs and then some people go off to the pub afterwards for however long. there's a google group too https://groups.google.com/forum/#!forum/hott-nyc

whats yr maths background and how does it bring you to HoTT?

lollercoaster of rove (s.clover), Saturday, 9 November 2013 22:12 (six years ago) link

'how did you first know christ?'

j., Saturday, 9 November 2013 22:20 (six years ago) link

pretty much

lollercoaster of rove (s.clover), Saturday, 9 November 2013 22:26 (six years ago) link

constructivism had that flavor

lollercoaster of rove (s.clover), Saturday, 9 November 2013 22:26 (six years ago) link

How are we supposed to search for this thread title?

yeah sorry, had that thought while making the thread but couldnt resist lol. bookmark it, i guess?

s clover we should def homotope it up itt, stoked. what books are you reading? my course is based on munkres (<3) but prof is doing some additional topics, so far i've only looked at hatcher... it's all very intense, though. i slayed point-set but algebraic topo makes me feel v dumb

flopson, Saturday, 9 November 2013 22:31 (six years ago) link

had some halfbaked thoughts while hi the other day about some group theoryish intepretation of (basic) music theory. trying to figure out how to make like, arpeggios/chords subgroups of keys/scales?? i don't know enough group theory tho

flopson, Saturday, 9 November 2013 22:37 (six years ago) link

Don't have much background in this area per se, but have some background in math in general, was on the math team in junior high and then at the Bronx High School of Science, undergrad degree in math at Yale and graduate degree from NYU. First professor I had Freshman year was topologist William S. Massey, at graduate school I took the topology course from Sylvain C, but it was kind of easy and I didn't really learnd too much and most of NYU is about applied math anyway. Actually guy who wrote that music and math paper did a post-doc in topology at NYU, now he is at Lehman College. Sort of curious about this topic but more importantly like the idea that it is free and of being on an equal footing with the other students, other people not currently in academia but presumably mathematically literate - have toyed with idea of going back to finish (start?) thesis and get PhD now that my advisor is the chair but don't really want to deal with have to crank out research-level material, plus I didn't always like the Eloi vs. Morlocks setup of formal grad school, as I recently discussed with former ilxor Casuistry.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 22:45 (six years ago) link

I don't know how much higher math you really use to understand music or music theory, the article I was talking about basically says that he thinks a lot of mathematical research on music is sort of bogus, drawing a picture or creating blinking lights that sort of looks like what music is doing. To him the most interesting thing seemed to be the way the similar processes of collaboration jazz improvisation and mathematical research.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 22:47 (six years ago) link

i teach high school math but im an econ undergraduate and yall are simply adding fuel to the fire that rages inside me that i shd not be teaching math

shiny trippy people holding bandz (m bison), Saturday, 9 November 2013 22:50 (six years ago) link

plus I didn't always like the Eloi vs. Morlocks setup of formal grad school,

what does this mean?

flopson, Saturday, 9 November 2013 22:52 (six years ago) link

xp would u rather be teaching econ? my first major was in econ, then i was like ah fuck it and turned my math minor into a full major

flopson, Saturday, 9 November 2013 22:53 (six years ago) link

The few mathematical ideas I use to think about music are:
*Thinking about the twelve semitones as the Abelian group Z12. (supposed to be a subscript)
*Looking for least common multiples when counting out polyrhythms
*Realizing that the names of the intervals are Ordinal Numbers and
*Realizing that sometimes there are Fencepost Problems in either counting out beats or even in that the octave is the same as the one, which is why some people talk about a heptatonic scale

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 22:55 (six years ago) link

*Thinking about the twelve semitones as the Abelian group Z12. (supposed to be a subscript)

yeah this was basically the extent of my ruminations lol

flopson, Saturday, 9 November 2013 22:56 (six years ago) link

well hey you know

http://en.wikipedia.org/wiki/Set_theory_%28music%29

j., Saturday, 9 November 2013 22:58 (six years ago) link

Fully funded PhD student with good background (perhaps trained abroad) and famous advisor, who can sail through qualifyings, has good chance of helping advisor push out papers and securing post-doc and just generally burnishing his legacy = Eloi
Rest = Morlocks

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 22:58 (six years ago) link

hmm, in the humanities the 'fully funded' part of the distinction doesn't really apply anymore at lots of places, programs looking to trim, improve graduation rates/times etc. figured maybe they should only admit those who they could fund

the other part, though…

j., Saturday, 9 November 2013 23:00 (six years ago) link

Someone told me Hindemith was into group or set theory as it applies to music but I couldn't find a reference. Maybe that Wiki page will have.

Telling you, that Fencepost thing saved me some headaches.

Oh yeah, one more thing
*Thinking about musical entities as partitions- triads as partitioning into three (with the fourth being a "generalized, augmented third*), seventh chords as partitioned into four (with the second between the seventh and the octave as a *generalized, diminished third*)

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 23:02 (six years ago) link

homotopy type theory isn't exactly homotopy theory bear in mind -- its this wild new realization that homotopy theory is precisely isomorphic to that branch of logic known as martin-lof type theory, and this all works only in a constructivist setting. so you have math/logics ppl without much topology background (hi!) and topology people trying to understand type theoretic notation all sort of in the mix together. i have a coworker with some topology so he's good at explaining things like fibrations and fundamental groups etc. oh right and the other part of the hott project is now you have a setting in which the claim is you can do the foundation of _all maths_ as an alternative to set theory, so eventually (tho it may be 6 mos before we get there, if we can keep up the momentum) we'll stop just building up the theory and do applications and use it to do classic results in e.g. actual homotopy theory, set theory, category theory, analysis etc.

lollercoaster of rove (s.clover), Saturday, 9 November 2013 23:07 (six years ago) link

the hatcher book is very approachable but it does sort of require someone with a bit of background to explain what he means by certain things, since the geometrical intuitions aren't totally obvious without someone drawing things or waving their hands or etc. to illustrate movement.

lollercoaster of rove (s.clover), Saturday, 9 November 2013 23:08 (six years ago) link

sounds cool xp

flopson, Saturday, 9 November 2013 23:16 (six years ago) link

xp would u rather be teaching econ? my first major was in econ, then i was like ah fuck it and turned my math minor into a full major

― flopson, Saturday, November 9, 2013 4:53 PM (17 minutes ago) Bookmark Flag Post Permalink

there are many things for which i am better qualified to teach. don't get me wrong, i know the hs curricula v well, i just didnt take much advanced math and sometimes feel like i am training my kids for a sport ive never seen or played before. being the good economist, tho, i know my comparative advantage is in the high-need HS math field rather than the social studies or journalism positions i'd have an absolute advantage in.

shiny trippy people holding bandz (m bison), Saturday, 9 November 2013 23:19 (six years ago) link

Now I remember the problem with math, you have to beef up all this apparatus, before you can really understand or prove anything- except for trivial variations on the proofs in the book with slightly different initial conditions- let alone do a calculation, for what seems like an eternity.

I Wanna Be Blecch (James Redd and the Blecchs), Saturday, 9 November 2013 23:22 (six years ago) link

let me restate to be sure i understand tho -- "i have an assignment of the integers from 1 to 100 to 100 respective values in R. i would like to make a new assignment of the same form N_[1-100] -> R, but with the condition that the sum of values in the codomain agree with the prior one, and with some sort of smoothing applied."

If that's correct, yeah, you need to decide the tradeoff yr willing to make, towards what end, between similarity and smoothness. i mean a lazy and decent thing to do is just to take some sort of quadratic or cubic interpolation on the points, then "bump" it into shape with a second pass that makes the sum tie out while minimizing MSE as you describe.

the klosterman weekend (s.clover), Thursday, 1 December 2016 20:38 (three years ago) link

that's correct. looking for something simple and quick

flopson, Thursday, 1 December 2016 20:55 (three years ago) link

friend linked me to: https://en.wikipedia.org/wiki/Mollifier

flopson, Thursday, 1 December 2016 20:58 (three years ago) link

neat!

the klosterman weekend (s.clover), Wednesday, 7 December 2016 05:22 (three years ago) link

two weeks pass...

was led by this tweet

https://twitter.com/sigfpe/status/811704836622159872

to this book:

https://arxiv.org/abs/1612.06373

flopson, Thursday, 22 December 2016 00:37 (two years ago) link

wiki:

In mathematics, singularity theory studies spaces that are almost manifolds, but not quite. A string can serve as an example of a one-dimensional manifold, if one neglects its thickness. A singularity can be made by balling it up, dropping it on the floor, and flattening it.

lol, awesome

flopson, Thursday, 22 December 2016 00:41 (two years ago) link

You mean like orbifolds?

Stars on 45, Where Are You? (James Redd and the Blecchs), Thursday, 22 December 2016 01:00 (two years ago) link

two weeks pass...

<3 sigfpe

the klosterman weekend (s.clover), Wednesday, 11 January 2017 22:52 (two years ago) link

https://en.wikipedia.org/wiki/Cox%E2%80%93Zucker_machine

flopson, Friday, 20 January 2017 14:31 (two years ago) link

Man if I had endless time I would read that Ghys book linked above

Guayaquil (eephus!), Friday, 20 January 2017 16:17 (two years ago) link

otm

droit au butt (Euler), Friday, 20 January 2017 16:34 (two years ago) link

why need endless time? do you read novels in your spare time? think of it as one of those!

flopson, Friday, 20 January 2017 16:35 (two years ago) link

maybe you can read math books at the same speed as you do novels, not me

Guayaquil (eephus!), Friday, 20 January 2017 16:36 (two years ago) link

why does it have to be at the same speed?

flopson, Friday, 20 January 2017 16:38 (two years ago) link

at one point in my life I had the habit of reading a page of Hilbert's Geometry and the Imagination a day. I never finished it but it doesn't matter; it was a blast

flopson, Friday, 20 January 2017 16:43 (two years ago) link

:)

A Simple Twist of McFate (James Redd and the Blecchs), Saturday, 21 January 2017 19:42 (two years ago) link

https://sites.tufts.edu/gerrymandr/

"A 5-day summer school will be offered at Tufts University from August 7-11, 2017, with the principal purpose of training mathematicians to be expert witnesses for court cases on redistricting and gerrymandering."

𝔠𝔞𝔢𝔨 (caek), Sunday, 29 January 2017 22:51 (two years ago) link

that's hot. I wish I could audit that

El Tomboto, Monday, 30 January 2017 04:49 (two years ago) link

two months pass...

Is there in iPhone app that I can use to solve or graph or factor algebraic equations? Basically do what my old TI-89 could do back in my high school days, (except in color obv.)?

Mr. Snrub, Tuesday, 11 April 2017 00:17 (two years ago) link

two weeks pass...

love to read stats bantz http://davegiles.blogspot.com/2011/09/micronumerosity.html

𝔠𝔞𝔢𝔨 (caek), Friday, 28 April 2017 14:56 (two years ago) link

asically do what my old TI-89 could do back in my high school days, (except in color obv.)?

this is a betrayal

j., Friday, 28 April 2017 15:27 (two years ago) link

Mr. Snurb, Wolfram Alpha is useful. It even has an iPhone app. In addition to factoring, it can be used to integrate or even solve mildly complicated PDE/sODEs. The syntax, IMO, is much nicer than a calculator you can use natural language or TeX-like formatting.

Allen (etaeoe), Saturday, 29 April 2017 23:34 (two years ago) link

one month passes...

https://www.youtube.com/watch?v=AmgkSdhK4K8

flopson, Wednesday, 31 May 2017 17:16 (two years ago) link

one month passes...

Very sad: http://ifpnews.com/exclusive/iran-math-genius-die-cancer/

o. nate, Sunday, 16 July 2017 00:29 (two years ago) link

:(

Under Heaviside Manners (James Redd and the Blecchs), Sunday, 16 July 2017 00:58 (two years ago) link

two months pass...

voevodsky dead at 51 https://www.ias.edu/news/2017/vladimir-voevodsky

fields metalist dropping like flies

a terrible tragedy for math. he supervised to a close friend of mine, who told me they had been making progress on some problems as recently as this summer. needless to say friend is devastated

flopson, Sunday, 1 October 2017 22:15 (two years ago) link

RIP

Must admit I was thinking this revive would be about Monty Hall problem.

Two-Headed Shindog (Rad Tempo Player) (James Redd and the Blecchs), Sunday, 1 October 2017 22:20 (two years ago) link

extremely worthwhile Voevodsky content:

https://www.youtube.com/watch?v=O45LaFsaqMA

flopson, Monday, 2 October 2017 00:14 (two years ago) link

two months pass...

that's what you get for inventing calculus bitch lmao https://t.co/qwE6dL6fNH

— daddy. (@TayWest) December 12, 2017

j., Thursday, 14 December 2017 21:21 (one year ago) link

three months pass...

https://en.wikipedia.org/wiki/Spherical_coordinate_system#Integration_and_differentiation_in_spherical_coordinates

does anybody know the line elements in 4D hyperspherical coordinates or how to go about deriving them? i need to know for a school project and didn't realize this information would be so hard to find lol

had (crüt), Tuesday, 20 March 2018 15:06 (one year ago) link

ok i guess this is the way to do it:

https://math.stackexchange.com/questions/74442/line-element-dl-in-spherical-coordinates-derivation-diagram

had (crüt), Tuesday, 20 March 2018 22:13 (one year ago) link

wow that was easy

had (crüt), Tuesday, 20 March 2018 22:34 (one year ago) link

Really?

Whiney On The Moog (James Redd and the Blecchs), Wednesday, 21 March 2018 01:49 (one year ago) link

Seems like you “just” stick another sin and cos on the end and then “just” do your calculations

Whiney On The Moog (James Redd and the Blecchs), Wednesday, 21 March 2018 01:52 (one year ago) link

four months pass...

So about those octonions

3-Way Tie (For James Last) (James Redd and the Blecchs), Sunday, 29 July 2018 01:17 (one year ago) link

they squirt ink and make you cry

adam the (abanana), Sunday, 29 July 2018 01:36 (one year ago) link

Lol

3-Way Tie (For James Last) (James Redd and the Blecchs), Sunday, 29 July 2018 02:03 (one year ago) link

PY DERE! Have a Jupyter notebook question that I may hit you with in a little bit

3-Way Tie (For James Last) (James Redd and the Blecchs), Monday, 30 July 2018 20:52 (one year ago) link

Okay, been trying to make slides using nbconvert. It ends up creating an html version but no slides.

3-Way Tie (For James Last) (James Redd and the Blecchs), Tuesday, 31 July 2018 13:43 (one year ago) link

Oh, looks like a copy of reveal.js is needed.

3-Way Tie (For James Last) (James Redd and the Blecchs), Tuesday, 31 July 2018 14:54 (one year ago) link

six months pass...

going to be learning random graph theory this spring, maybe some random matrix theory

flopson, Sunday, 24 February 2019 20:51 (nine months ago) link

Cool.

Follow-up video to the prior one:
https://www.youtube.com/watch?v=ea7lJkEhytA

Only a Factory URL (James Redd and the Blecchs), Sunday, 24 February 2019 20:56 (nine months ago) link

one month passes...

some figures missing from that version??

moose; squirrel (silby), Thursday, 28 March 2019 16:00 (eight months ago) link

seven months pass...
two weeks pass...

I am now HS Geometry revisiting.

Irae Louvin (James Redd and the Blecchs), Saturday, 30 November 2019 23:38 (one week ago) link

take a look at the second volume in felix klein's 'elementary mathematics from a higher standpoint', his course for teachers of school mathematics!

https://www.springer.com/de/book/9783662494400

j., Sunday, 1 December 2019 03:09 (one week ago) link

really enjoyed relearning HS geom for the GRE

flopson, Sunday, 1 December 2019 06:06 (one week ago) link


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