
24 votes

A brief history of tricky mathematical tiling
10 votes 
Maths anxiety
12 votes 
The humbling of the maths snobs
10 votes 
Can YOU win rock, paper, scissors against Grey? 99.9999999% will fail.
40 votes 
Polyhedra world
8 votes 
Quantum Computing Since Democritus
7 votes 
The inability to count correctly: Debunking the US National Institute of Standards and Technology's calculation of the cryptographic security level of Kyber512
25 votes 
The Lindy Effect (Toby Ord)
3 votes 
The early history of counting
6 votes 
Knot theory: How the most useless branch of math could save your life
15 votes 
Are there politics in mathematics?
Curious if there are movements within the governance or research pertaining to the field that act to promote or suppress certain ideas? Was watching the “Infinity explained in 5 different levels”...
Curious if there are movements within the governance or research pertaining to the field that act to promote or suppress certain ideas? Was watching the “Infinity explained in 5 different levels” and thought… maybe there are trends for or against interpretations and/or abstractions that get a rise in people…
33 votes 
Obituary  Evelyn Boyd Granville, mathematician and programmer, spaceflight trailblazer (1924—2023)
15 votes 
Teaching myself calculus at sixtyfive
24 votes 
Steffen's polyhedron is a flexible concave polyhedron. Euler thought such a shape was impossible. I also show infinitesimally flexible polyhedrons and bistable polyhedrons.
13 votes 
The Fibonacci Matrix
12 votes 
The game of Set (and some variations)
14 votes 
California needs real math education: an essay
16 votes 
Any good math textbook/book recommendations
I would like to get slightly more educated in mathematics again  I took some basic calculus and linear algebra classes while doing my degree, but most likely forgot what I learned for the most...
I would like to get slightly more educated in mathematics again  I took some basic calculus and linear algebra classes while doing my degree, but most likely forgot what I learned for the most part. Are there any good books that you guys would recommend for someone who wants to learn math again?
13 votes 
Seximal: a better way to count
24 votes 
Can you set a clock using a light sensor to detect sunrise and sunset?
While pondering an offgrid microcontroller project, I got to wondering: A light sensor can obviously detect day vs night. So it could be used as a very cheap way to set a device's clock  but how...
While pondering an offgrid microcontroller project, I got to wondering: A light sensor can obviously detect day vs night. So it could be used as a very cheap way to set a device's clock  but how accurately? To within an hour? A few minutes? How would you do it?
Questions that arose from this include:
 Should it detect dawn/dusk (light <> dark transition), or noon/midnight (brighest/darkest time) ?
 How do dawn/dusk times relate to clock time? Does it depend on lat/long?
 If using dawn/dusk, what light level threshold to use?
 The same threshold for dawn & dusk, or different ones?
 Better to detect a darker threshold (start of dawn, end of dusk) or a lighter one?
 Some days will be lighter/darker than others, so how to manage averaging of times?
 How accurate could it be made?
My naïve first stab at this would be: Pick a light threshold. Record the dawn/dusk times according to that threshold. Average them, call that "noon", and gradually tweak the clock time over several days to bring it into line with the sensed/calculated "noon"  but a searching for graphs of sunrise/sunset times quickly showed that the midpoint of sunrise & sunset is not noon.
Googling threw up lots of results for sensor lights combining a clock and a photocell, but I couldn't find anything about using the photocell to set the clock. So does anyone know if this has been tried before? Is it a nonstarter for some reason?
Edit:
Perhaps it's worth sharing the project I had in mind, which is a rain alarm so I can rush out and get the washing in from the line when it starts to rain. I was thinking how annoying it would be if I left it switched on and it rained in the middle of the night and the alarm woke me up. So I decided should automatically avoid triggering during the sleeping hours of night (say 10pm to 8am). My first thought was a photocell so it wouldn't trigger when it's dark. Then I remembered that it gets light at 3am at the moment, which wouldn't work. So it needs a clock. How to set the clock:
 Manually  Needs a user interface with buttons and a display. Seems overkill just for a clock.
 Serial port  Clunky to plug a laptop in just to set the clock.
 WiFi  Needs a username and password or WPS, and an ESP32 or similar  again seems overkill just to get the time.
 GPS  also overkill and expensive.
19 votes 
The network of collaboration among rappers and its community structure
9 votes 
History of transcendental numbers
7 votes 
Numerically Stable RWKV Language Model
11 votes 
The spool paradox
4 votes 
UK hobbyist discovers new unique shapes, stunning mathematicians
17 votes 
The derivative isn't what you think it is
8 votes 
The insane engineering of MRI machines
3 votes 
GradIEEEnt half decent: The hidden power of imprecise lines
9 votes 
An aperiodic monotile exists!
21 votes 
Explore a universe of numbers and arithmetic in our new interactive math game, Hyperjumps!
3 votes 
The story behind the Packing Chromatic paper
5 votes 
Shipping graphing calculator
3 votes 
Mathematics and chess
3 votes 
KeenType 1.0.0
6 votes 
Once a millennium alignment of all three norths
5 votes 
Why the super rich are inevitable?
14 votes 
How do fireflies flash in sync? Studies suggest a new answer.
3 votes 
KeenWrite 2.10.0: R meets TeX
4 votes 
RIP: Kathleen Booth, the inventor of assembly language
23 votes 
A climate love story
3 votes 
The more gender equality, the fewer women in STEM
14 votes 
Why are quintic equations not solvable?  the Galois theory approach
3 votes 
Penrose Unilluminable Room is a room with mirrored walls that can't be fully illuminated by a single point source of light
3 votes 
How cryptocurrencies actually work
7 votes 
The hyperbolic geometry of DMT experiences
7 votes 
Repulsive Curves
4 votes 
Why everyone ignored the world's best mathematician
4 votes 
A mathematician explains what Foundation gets right about predicting the future
5 votes 
How do I calculate my family's "average family location"?
So, I just listened to a This American Life podcast called Ghost in the Machine. In one of the stories, a man decides to calculate, every week, the Average Family Location of his family. By that,...
So, I just listened to a This American Life podcast called Ghost in the Machine. In one of the stories, a man decides to calculate, every week, the Average Family Location of his family. By that, he means: once you add everyone's coordinates for every coordinate in which they've been in that period, what city/location represents the average point between them all?
I decided to do the same for my family, which will be much easier because there are no touring musicians among us. The one complication is that a good chunk of the family is on other continents, and I wouldn't want us to "meet" in the middle of the ocean. So some approximation might be warranted.
I'd be happy if someone could provide me the math, I'm fairly confident I would be able to do it with a calculator or maybe put into some crude Python. I don't think I need to make a weekly report, since we're not that mobile. Maybe twice a year, or once every two months.
Thanks!
Edit: I don't know much math
Edit2: holy shit this is not simple at all! Now I feel kinda bad for throwing this problem at you guys. I really thought it would be quick and easy!
9 votes