Uncategorized
- Math
Turn of the Screw
“What we are told about Archimedes is a mix of a few hard facts and many legends,” Sherman Stein of the University of California, Davis notes in his book Archimedes: What Did He Do Besides Cry Eureka? A three-bladed Archimedes screw. Courtesy of Chris Rorres. I was reminded of that statement when my son Kenneth […]
- Math
Conquering Catalan’s Conjecture
Innocent-looking problems involving whole numbers can stymie even the most astute mathematicians. As in the case of Fermats last theorem, centuries of effort may go into proving such tantalizing, deceptively simple conjectures in number theory. Now, Preda Mihailescu of the University of Paderborn in Germany finally may have the key to a venerable problem known […]
- Animals
Oops. Woodpecker raps were actually gunshots
The knock-knock noises recorded last winter that raised hopes for rediscovering the long-lost ivory-billed woodpecker in Louisiana turn out to have been gunshots instead of bird noises.
- Math
Algebra, Philosophy, and Fun
I don’t often encounter the words “philosophy” and “fun” right next to the term “algebra.” Nowadays, these words don’t seem to fit together comfortably. However, the three terms do appear in the title of an engaging little book called Philosophy and Fun of Algebra, written by Mary Everest Boole (1832–1916) and published in 1909. I […]
- Tech
Making a Little Impression: New chip-making method may mold the industry
A simple mechanical means of embossing silicon may offer an alternative to conventional chip-making methods.
- Health & Medicine
Stem Cell Gain: Bone marrow cells seem to have what it takes
Tests show that a rodent bone marrow cell similar to one found in people acts as a multipurpose stem cell, much as embryonic stem cells do.
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Hostile Intent: Abused kids face up to angry expressions
Physical abuse at home apparently tunes a school-age child's perceptual system to pick up signs of anger in others' facial expressions.
- Astronomy
Planetary System in the Making? Stellar eclipse hints at planet-forming debris
Astronomers reported the first evidence that a young star is periodically eclipsed by a stream of debris, possibly an orbiting belt of asteroids held in place by a massive, unseen planet.
- Chemistry
Molecule Sorting: Antibody membrane lends a hand
A new membrane may make it easier to separate mixtures of drug molecules that exist in mirror-image versions into their two components.
- Health & Medicine
Enough Isn’t Enough: An epidemic of vitamin D deficiency
Many U.S. women of childbearing age, particularly those of African descent, lack sufficient vitamin D even though they consume the recommended amount.
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19076
Regarding this article, as planes fly low over the bay to land at San Francisco airport, wing vortices frequently bend down and become twin waterspouts that last up to 20 seconds. Dave GrossmanPalo Alto, Calif.
- Humans
Dangerous Wake: Wing vortices yield a deadly secret
A new mathematical analysis of an aeronautical hazard known as wake turbulence could someday lead to improved air safety and increase the number of flights at major airports.
