Ham sandwich theorem. Not to be confused with the "squeeze theorem" (sometimes called the "sandwich theorem").
Naming[edit] A ham sandwich History[edit] According to Beyer & Zardecki (2004), the earliest known paper about the ham sandwich theorem, specifically the n = 3 case of bisecting three solids with a plane, is by Steinhaus (1938). Beyer and Zardecki's paper includes a translation of the 1938 paper. An App That Encrypts, Shreds, Hashes and Salts. The Wickr app.
When it comes to mobile apps and social networks, the devil, increasingly, is in the default settings. Companies have little, if any, incentive to let users opt out of services that siphon their personal data back to the advertisers who pay their bills. A new formula for avoiding supermarket queues. Supermarket queues are dreaded by many.
In the TV series ‘Supernatural’, people standing in an endless queue are used as an example of what hell really looks like. (Photo: Colourbox) - StumbleUpon. Perpetual Futility A short history of the search for perpetual motion. by Donald E.
Simanek Popular histories too often present perpetual motion machines as "freaks and curiosities" of engineering without telling us just how they were understood at the time. They also fail to inform us that even in the earliest history of science and engineering, many persons were able to see the futility and folly of attempts to achieve perpetual motion. Sometimes a particular device comes to us with a label, such as "Bishop Wilkins' magnetic perpetual motion machine.
" Popular articles leave the impression that the inventor believed it was a perpetual motion machine. Bhaskara's Wheels. Villard de Honnecourt was born in the late 12th century and probably lived and worked in the north of France from 1225 to 1250. An Overview of Cryptography. As an aside, the AES selection process managed by NIST was very public.
A similar project, the New European Schemes for Signatures, Integrity and Encryption (NESSIE), was designed as an independent project meant to augment the work of NIST by putting out an open call for new cryptographic primitives. NESSIE ran from about 2000-2003. While several new algorithms were found during the NESSIE process, no new stream cipher survived cryptanalysis. As a result, the ECRYPT Stream Cipher Project (eSTREAM) was created, which has approved a number of new stream ciphers for both software and hardware implementation. Similar — but different — is the Japanese Government Cryptography Research and Evaluation Committees (CRYPTREC) efforts to evaluate algorithms submitted for government and industry applications.
Whats Special About This Number? Lecture Slides and Video Archives. Prime Time - Mathematicians have tried in vain to this day to discoversome oreder inthe sequence of prime numbers... Methods for Studying Coincidences. One of my favorite mathematics papers of all time is called “Methods for Studying Coincidences.”
By Persi Diaconis and Frederick Mosteller, it aims to provide a rigorous mathematical framework for the study of coincidences. Using probabilistic analysis, the paper explores everything from why we see newly learned words almost immediately after first learning them, to why double lottery winners exist, to even the frequency of meeting people with the same birthday. They even explore whether or not we can statistically state that Shakespeare used alliteration, or if the frequency of words with similar-sounding beginnings could simply be explained by chance alone. For example, when it comes to newly learned words, we are often astonished that as soon as we learn a new word, we begin to see it quite frequently, or at least soon after we learn it.
Now it could just be due to our heightened perception. With a large enough sample, any outrageous thing is likely to happen. Mathematical Atlas: A gateway to Mathematics. Welcome!
This is a collection of short articles designed to provide an introduction to the areas of modern mathematics and pointers to further information, as well as answers to some common (or not!) Questions. The material is arranged in a hierarchy of disciplines, each with its own index page ("blue pages"). To reach the best page for your interests, use whichever of these navigation tools ("purple pages") you prefer: For resources useful in all areas of mathematics try 00: General Mathematics. There is a backlog of articles awaiting editing before they are referenced in the blue pages, but you are welcome to snoop around VIRUS WARNING: The Mathematical Atlas receives but does not send mail using the math-atlas.org domain name. Please bookmark any pages at this site with the URL This URL forces frames; for a frame-free version use. From Wolfram MathWorld. Poker is a card game played with a normal deck of 52 cards.
Sometimes, additional cards called "jokers" are also used. In straight or draw poker, each player is normally dealt a hand of five cards. Depending on the variant, players then discard and redraw cards, trying to improve their hands. Bets are placed at each discard step. How To Tie A Wind- And Fushnicken-Resistant Scarf Knot. New Mayan calendar discovered: world won't end in 2012. Earth has a new reason to celebrate.
It's looking like we will make it past Dec. 21, 2012. According to LiveScience, researchers have unearthed the oldest-known version of the ancient Maya calendar in the Guatemalan rainforest. Mathematical Atlas: A gateway to Mathematics. Perfect numbers. - StumbleUpon.
Pi: The Golden Spiral. Calculus and Differential Equations. StumbleUpon. Nerd Paradise : Calculating Base 10 Logarithms in Your Head. Calculating base 10 logarithms in your head on the fly is a lot easier than you may think.
It is simply a matter of memorization and a little estimation... First memorize all the single digit base 10 logs. Don't worry, it's not as painful as it sounds. I even made the chart for you: Remember this rule from high school? And what about this one, you remember it too? Good. Example #1: base 10 log of 400 That's the same thing as log(4*100) which equals log 4 + log 100. log of 4 you know from the table above. - StumbleUpon. The length of the polygonal spiral is found by noting that the ratio of inradius to circumradius of a regular polygon of sides is The total length of the spiral for an -gon with side length is therefore Consider the solid region obtained by filling in subsequent triangles which the spiral encloses.
Mathematica in Action. From Wolfram MathWorld. Wolfram Mathematica Online Integrator - StumbleUpon. Futility Closet - StumbleUpon. The MegaPenny Project. The MegaPenny Project. The MegaPenny Project. The Geometry of Linear Equations. Mathematical References - RF Cafe - StumbleUpon. - StumbleUpon.
Wolfram MathWorld: The Webs Most Extensive Mathematics Resource - StumbleUpon. Hypercube Projection - StumbleUpon. Nerd Paradise : Divisibility Rules for Arbitrary Divisors. Technology: Mathematically Proven. Pigeons.jpg (640×380) High speed video reveals the bizarre physics of an ordinary water droplet. HTML5 Sudoku. Language Appears to Shape Our Implicit Preferences.
The Tesseract. Weierstrass functions. Weierstrass functions are famous for being continuous everywhere, but differentiable "nowhere". Here is an example of one: It is not hard to show that this series converges for all x. In fact, it is absolutely convergent.