Automatic calculation of plane loci using Grobner bases and integration into a Dynamic Geometry System
Article by Gerh, Michael
In collection: Basically computer science
PDF: jsxgraph.uni-bayreuth.de/talks

Irrationality from the book
Article by Miller, Steven J and Montague, David
In collection: Easily explained
URL: arxiv.org/abs/0909.4913
PDF: arxiv.org/pdf/0909.4913v2

Deobfuscation is in NP
Article by Appel, Andrew W
In collection: Basically computer science
URL: cs.princeton.edu/~appel/papers

Ponytail Motion
Article by Joseph B. Keller
In collections: Easily explained, Basically physics
A jogger's ponytail sways from side to side as the jogger runs, although her head does not move from side to side. The jogger's head just moves up and down, forcing the ponytail to do so also. We show in two ways that this vertical motion is unstable to lateral perturbations. First we treat the ponytail as a rigid pendulum, and then we...
URL: epubs.siam.org/doi/abs/10.1137

A combinatorial approach to sums of two squares and related problems
In collections: About proof, Fun maths facts
Heath-Brown [6] suggested a short proof of the two squares theorem, thereby simplifying ideas of Liouville. Zagier [15] suggested a particularly neat form of this, a "One sentence proof". It consists of two suitable involutions on the finite set of the solutions of p = x 2 +4yz in positive integers. A parity argument...

Renyi's Parking Problem Revisited
Article by Matthew P. Clay and Nandor J. Simanyi
In collection: Easily explained
R\'enyi's parking problem (or $$1D$$ sequential interval packing problem) dates back to 1958, when R\'enyi studied the following random process: Consider an interval $$I$$ of length $$x$$, and sequentially and randomly pack disjoint unit intervals in $$I$$ until the remaining space prevents...
URL: arxiv.org/abs/1406.1781v2
PDF: arxiv.org/pdf/1406.1781v2

Paperfolding morphisms, planefilling curves, and fractal tiles
Article by Michel Dekking
In collections: Geometry, Things to make and do
An interesting class of automatic sequences emerges from iterated paperfolding. The sequences generate curves in the plane with an almost periodic structure. We generalize the results obtained by Davis and Knuth on the self-avoiding and planefilling properties of these...
URL: arxiv.org/abs/1011.5788v2
PDF: arxiv.org/pdf/1011.5788v2

Mathematics applied to dressmaking
Article by Christopher Zeeman
In collections: Easily explained, Fun maths facts, Things to make and do
Dressmaking can raise interesting questions in both geometry and topology. My own involvement began in Bangkok, where I once bought a dress-length of some rather beautiful Thai silk. Unfortunately when I got home all the dress-makers claimed it wasn't long enough to...
URL: lms.ac.uk/content/mathematics-
PDF: lms.ac.uk/sites/lms.ac.uk/file

New entry!
Check Digits
Web page by Jonathan Mohr
In collections: Basically computer science, Easily explained, Fun maths facts, Unusual arithmetic
A decimal (or alphanumeric) digit added to a number for the purpose of detecting the sorts of errors humans typically make on data entry.
URL: augustana.ualberta.ca/~mohrj/a

New entry!
Mathematics ClipArt
Web page by Florida Center for Instructional Technology
In collections: Art, Lists and catalogues
The Mathematics ClipArt collection includes 9,820 images for algebra, geometry, trigonometry, probability, money, number sense, and more., conveniently arranged in 222 galleries. This comprehensive set of illustrations for teachers and students consists of ClipArt for all levels of K-12 math classes....
URL: etc.usf.edu/clipart/galleries/

The term `angle' in the international system of units
Article by Michael P. Krystek
In collections: History, Notation and conventions
The concept of an angle is one that often causes difficulties in metrology. These are partly caused by a confusing mixture of several mathematical terms, partly by real mathematical difficulties and finally by imprecise terminology. The purpose of this publication is to...
URL: arxiv.org/abs/2101.01023v2
PDF: arxiv.org/pdf/2101.01023v2

Mathemagics
Article by Pierre Cartier
In collections: Notation and conventions, The act of doing maths
My thesis is:there is another way of doing mathematics, equally successful, and the two methods should supplement each other and not fight.
URL: ftp.gwdg.de/pub/misc/EMIS/jour

Maximum Matching and a Polyhedron With 0,1-Vertices
A matching in a graph $$G$$ is a subset of edges in $$G$$ such that no two meet the same node in $$G$$. The convex polyhedron $$C$$ is characterised, where the extreme points of $$C$$ correspond to the matchings in $$G$$. Where each edge of $$G$$ carries a real numerical weight, an efficient algorithm is described for finding a matching in $$G$$ with maximum weight-sum.
URL: nvlpubs.nist.gov/nistpubs/jres

The Strange and Surprising Saga of the Somos Sequences
Article by Gale, David
In collections: Fun maths facts, Integerology

What are some of the most ridiculous proofs in mathematics?
Web page by Anonymous
In collections: The act of doing maths, About proof
URL: quora.com/Mathematics/What-are

Renyi's Parking Problem Revisited
Article by Matthew P. Clay and Nandor J. Simanyi
In collection: Easily explained
R\'enyi's parking problem (or $$1D$$ sequential interval packing problem) dates back to 1958, when R\'enyi studied the following random process: Consider an interval $$I$$ of length $$x$$, and sequentially and randomly pack disjoint unit intervals in $$I$$ until the remaining space prevents...
URL: arxiv.org/abs/1406.1781v2
PDF: arxiv.org/pdf/1406.1781v2

Any Monotone Boolean Function Can Be Realized by Interlocked Polygons
Article by Erik D. Demaine and Martin L. Demaine and Ryuhei Uehara
In collections: Basically computer science, Easily explained, Geometry, Fun maths facts
We show how to construct interlocked collections of simple polygons in the plane that fall apart upon removing certain combinations of pieces. Precisely, interior-disjoint simple...
URL: erikdemaine.org/papers/Interlo
PDF: erikdemaine.org/papers/Interlo

A note on paradoxical metric spaces
Article by Deuber, W A and Simonovits, M and Os, V T S
URL: renyi.hu/~miki/walter07.pdf