ℝolliℵg M∀th Thr∑a∂

really enjoyed relearning HS geom for the GRE

https://www.nytimes.com/2020/02/05/science/quadratic-equations-algebra.html

https://www.poshenloh.com/quadraticdetail/

maybe ive just had the quadratics drilled into me very young, but his doesnt seem any more usable or memorable tbh

nice

smdh

it may be less useful for finding roots but it is also more useful for thinking about as a mental exercise, the sort in which considering an alternate solution to an established problem expands and sharpens one's mathematical reasoning skills.

this goes quickly from "WHAT IS GOING ON THE WORLD IS BROKEN" to "oh i know this"

https://www.youtube.com/watch?v=HJ_PP5rqLg0

good old Johnny Ball. he used to do this stuff on the tv when i was a kid.

how does the crossing out the even numbers bit work?

the binary thing is how you'd do multiplication in z80 assembly language where the instruction set only had addition and shifting (shiting right === integer division by 2)

yes, even numbers thing is a bit odd. it will map to the binary representation, but i'm not sure how yet

ah, odd just means that you have a remainder when dividing by 2

so his 121 = odd, even, even, odd, odd, odd

or, reading from bottom up, 1111001 = 64 + 32 + 16 + 8 + 1 = 121

(i can imagine trying to explain who johnny ball is to my younger colleagues in terms of being zoe ball's dad, only to then have to explain who zoe ball is)

I'm fleeing America for the sole reason that we (now they) don't say "maths"

good riddance, pervert

The biggest AmE/BrE mystery is why it’s “math” and “sports” vs “maths” and “sport”

if not for cricket we would be able to make progress on that mystery by looking into sabermetric

in the video, he's solving using only the figures in the right column. what do you do with the left column? i missed it somehow

j., idgi?

lol i had the same moment rvw

i hope that hes referring to johnny ball

frustrating that he uses the same numbers for his second example lol

and the left column will invariably resolve to 1... OH it's just used to produce even numbers so you can scratch out the corresponding number on the right, ok

RIP, JHC.

Perhaps I shouldn't post about it, but Euler has a very impressive ancestor in his genealogy.

Do you mean me or my namesake? True in both cases...

Ha, meant you, had almost forgotten about the original’s tutor.

My philosophy advisor's advisor was one of Trotsky's bodyguards!

True in both cases...

Heh, now I'm intrigued.

On my math side you get to Tarski, Brentano, Copernicus, Regiomontanus, and Oresme.
On my philo side you get the aforementioned Trotsky bodyguard (that's van Heijenoort), Pólya, Hilbert , Weierstrass, Gauss, Lagrange, Euler (!!!), Malebranche, and Leibniz.

I'm my own grandpa

In that case maybe you belong on this thread

Is there a button on the genealogy project to see the trunk of the tree going back? I am blind and did not see.

I don't know. I just follow the links back and back.

I wasn't really cut out to be an academic- I went back to grad school later in life and wasn't really in quite the right subject. Upon reflection many of my cohort of mathletes didn't go on to become research mathematicians - with some notable exceptions of course! My advisor was a nice guy but didn't really push, although he did get most other people through to the PhD but not to any big jobs that I know of. Sometimes I slightly regret I didn't try to work with the one guy whose father won a Nobel Prize or the other guy with an Erdős number of one.

That's how it is for most people. I chose my grad institution knowing that it was really only good in the one area I wanted to study, so it's a good pedigree even if I'd studied, like, number theory it would have been a trash place to be. (Or any other discipline except philo & theology, it's not a very good place to do grad work in general, but it's a wealthy place so it worked out.) The big advantage of my well-established advisors was that they taught me, from my 2nd year on, how to talk to big shots, the senior faculty at other universities that I'd meet at conferences. I.e. networking, still the most important skill I learned aside from first-order "here's how you solve a problem" etc.

ILX - COVID-77

Woke up in the middle of the night and thought about R. L. Moore for a second. Ugh.

Now thinking about Paul Garabedian, a more pleasant memory.

what's wrong with Moore?

I had at least one undergrad prof who'd been a doctoral student of his. He told us a story of how, when Moore taught courses to engineers, he'd bring a loaded gun to class, and told the engineers that if any of them asked a question in class, he'd shoot them.

Heard a similar story from that son of a Nobelist I mentioned. Applied mathematician is hired at UT Austin. Shows up for first semester of work, is greeted by R. L. Moore sitting there with a shotgun his lap. “What are you doing here, son?”
“I came to teach <insert applied math subject here>.”
“Oh no you aren’t.”

haha

what's wrong with Moore?

I had at least one undergrad prof who'd been a doctoral student of his. He told us a story of how, when Moore taught courses to engineers, he'd bring a loaded gun to class, and told the engineers that if any of them asked a question in class, he'd shoot them.

Posts Whose Second Paragraph Answers The Question Raised In Their First Paragraph

;)

RFI: best way to express a half open range in a non-or-quasi-mathematical setting.

maybe...

integers: "x, x+1 ... y-1"
reals: "from x up to but not including y"

but if "quasi-mathematical" is like programmers or physicists then [x, y) is understood or quickly understandable for both integers and reals, and certainly a <= x < b is fine.

not exactly what you're looking for but maybe useful

https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html

Thanks, already went with your last suggestion.

HI DERE!

Does anyone read the Cantor’s Paradise section of Medium?

never heard of it before, but just read this nice post on concentration bounds https://medium.com/cantors-paradise/concentration-of-measure-the-glorious-chernoff-bound-1e96777cc29d

The few things I’ve read have been pretty good so far.

Twitter programming language enthusiasts are the absolute worst promoters of category theory applicability.

Who's the picture at the top of this thread a picture of?