Recent theoretical, observational and computational results establish the possibility that gravitational waves produced by the dark energy created at the dawn of the universe affect the clock rate of silicon digital processors operating at very low temperatures.... 更多内容 >>

An extraordinarily creative Danish mathematician, inventor, and poet who often wrote under the Old Norse pseudonym "Kumbel" meaning "tombstone." A direct descendant of the Dutch naval hero of the 16th century who had the same name, Piet Hein was born in Copenhagen and studied at the Institute for Theoretical Physics of the University of Copenhagen (later the Niels Bohr Institute) and the Technical University of Denmark. ... 更多内容 >>

Today's blog post is a complete working MATLAB program investigating the crossed ladders problem. Download a copy of the program via the link at the end. Publish it again with the publish command or the publish editor tab.... 更多内容 >>

Here is a classic puzzle. A pair of ladders leaning against the sides of an alley form a lopsided cross. Each ladder is propped against the base of one wall and leans against the opposite wall. If one ladder is 30 feet long, the other 20 feet long, and the point where they cross 10 feet above the ground, how wide is the alley?... 更多内容 >>

We say that a deck of playing cards is completely shuffled if it is impossible to predict which card is coming next when they are dealt one at a time. So a completely shuffled deck is like a good random number generator. We saw in my previous post that a perfect faro shuffle fails to completely shuffle a deck. But a riffle shuffle, with some randomness in the process, can produce complete shuffling. How many repeated riffle shuffles does that take?... 更多内容 >>

When a deck of playing cards is shuffled perfectly, the result is not random. A perfect shuffle places the cards in a mathematically precise order. As a result, when the most common version of a perfect shuffle is repeated eight times, the deck returns to its original state.... 更多内容 >>

When the starting point of Newton's method is not close to a zero of the function, the global behavior can appear to be unpredictable. Contour plots of iteration counts to convergence from a region of starting points in the complex plane generate thought-provoking fractal images. Our examples employ the subject of two recent posts, the historic cubic $x^3-2x-5$. ... 更多内容 >>

Use the historic cubic polynomial $x^3 - 2x - 5$ to test a few zero-finding algorithms. ... 更多内容 >>

The cubic polynomial $x^3 - 2x - 5$ has a unique place in the history of numerical methods.... 更多内容 >>

This is the story of how John Todd saved what was to become one of the world's most important research institutions from destruction at the end of World War II.... 更多内容 >>