All Stories by Ivars Peterson
- Math
Tilt-A-Whirl Chaos (II)
Tilt-A-Whirl in action. Sellner Manufacturing Co. The Tilt-A-Whirl amusement park ride serves as a wonderful example of a chaotic system. The unpredictable motion of the Tilt-A-Whirl’s cars occurs when the ride’s seven platforms travel at a speed of about 6.5 revolutions per minute along the undulating, circular track (see Tilt-A-Whirl Chaos (I), April 22, 2000). […]
- Earth
Impurities clock crystal growth rates
A novel method for measuring tiny amounts of hydrogen-containing impurities allows researchers to determine growth rates along different directions in a quartz crystal.
- Math
Tilt-A-Whirl Chaos (I)
Tilt-A-Whirl. Sellner Manufacturing Co. Schematic drawing (top view) showing the Tilt-A-Whirl’s geometry. Much of the fun of an amusement park ride results from its stomach-churning, mind-jangling unpredictability. The Tilt-A-Whirl, for example, spins its passengers in one direction, then another, sometimes hesitating between forays and sometimes swinging abruptly from one motion to another. A rider never […]
- Math
Hiding in DNA
Spies might have to start boning up on molecular biology to pass along and decipher secret messages. During World War II, German spies used microdots to hide information in plain view. Consisting of a greatly reduced photograph of a typed page, a microdot could be pasted on top of a printed period at the end […]
- Math
Hiding in DNA
Spies might have to start boning up on molecular biology to pass along and decipher secret messages. During World War II, German spies used microdots to hide information in plain view. Consisting of a greatly reduced photograph of a typed page, a microdot could be pasted on top of a printed period at the end […]
- Math
Random packing of spheres
A new definition of random packing allows a more consistent and mathematically precise approach to characterizing disordered arrangements of identical spheres.
- Math
Orbiting in a figure-eight loop
Three gravitationally interacting bodies of equal mass can, according to precise calculations, trace out a figure-eight-shape orbit in space.
- Math
Stepping Beyond Fibonacci Numbers
Trying variants of a simple mathematical rule that yields interesting results can lead to additional discoveries and curiosities. The numbers 1, 1, 2, 3, 5, 8, 13, 21, 34, and 55 belong to a famous sequence named for the Italian mathematician Fibonacci, who lived more than 700 years ago. Each consecutive number is the sum […]
- Math
Stepping Beyond Fibonacci Numbers
Trying variants of a simple mathematical rule that yields interesting results can lead to additional discoveries and curiosities. The numbers 1, 1, 2, 3, 5, 8, 13, 21, 34, and 55 belong to a famous sequence named for the Italian mathematician Fibonacci, who lived more than 700 years ago. Each consecutive number is the sum […]
- Math
The Incredible Pi Code
Extending this colored grid reveals (to some eyes) a provocative portrait. Researchers have expended a great deal of effort computing as many of those digits as computer technology and mathematical methods allow. Last year, Yasumasa Kanada of the University of Tokyo calculated pi to 206,158,430,000 decimal digits. A high school student has now smashed that […]
- Math
DNA’s Error-Detecting Code
Computers employ a variety of schemes to check whether a chunk of digital information–transmitted as a message, stored in a database, or functioning as a set of instructions–remains error-free. Such error-detection codes would detect, for example, the change of one bit from 0 to 1 or 1 to 0 in corrupted data. Nucleotides may be […]
- Math
Abbott and Costello’s Wacky Math
The Math in the Movies Web page (http://world.std.com/~reinhold/mathmovies.html) provides an annotated list of films in which mathematics plays some sort of role. The choices range from the calculus lessons of Stand and Deliver to the mystifying numerology of the 1998 thriller Pi. Among the notable omissions are several movies featuring the comedy team of Bud […]
