Uncategorized
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18961
I detect a blind spot in this article. Theorists were quick to offer explanations of why the fine-structure constant might have been different 12 billion years ago. But no one thought to question the chain of reasoning that led to that conclusion. We know that quasar spectra are drastically redshifted during their multibillion-year journey to […]
- Physics
Constant Changes
Evidence from the early universe that one of the so-called constants of nature, known as alpha, was once slightly smaller than it is today hints that the laws of physics themselves may vary over time and space.
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18969
If, as it appears from “Ill winds,” dust storms are so important, and if they can be tracked from space, it would seem as though the weather bureaus should give dust storm warnings, as they do for hurricanes, tornados, and thunderstorms. It might be difficult to get across to government bureaus that this is important, […]
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From the October 3, 1931 issue
A SEA-GOING LIZARD FROM GALAPAGOS When Darwin, as a young naturalist just out of school, visited the Galpagos islands, he saw a number of things that helped to crystallize and precipitate in his mind the concept, already seeded there, that later revolutionized all biology and much of philosophy. Not the least provocative of speculation was […]
- Math
Knot Views
Interested in playing around with some mathematical knots? Manuel Arala Chaves of the University of Porto in Portugal has created a table illustrating all 75 knots with up to 9 crossings in their standard representation. If your computer can handle LiveGraphics3D, you can manipulate the knots in three dimensions and look at them from different […]
- Math
Follow the Leader
In the sport of orienteering, a competitor uses a detailed map (and perhaps a compass) to navigate his or her way across varied terrain following a course drawn on the map. Selecting the best available route, each participant races from one marker to the next in the required sequence. The winner is the person who […]
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18976
The story correlates red tides in Florida with Saharan dust storms. The cover story of the same issue (“Dust, the thermostat,” p. 200: Dust, the Thermostat) dealt, in part, with dust blowing across the Mediterranean Sea and the Atlantic Ocean. Are there “red tides” in these areas? Are they correlated with Saharan dust? David D. […]
- Earth
Rain of foreign dust fuels red tides
Soil particles from Africa, raining out from clouds over the Americas, may trigger the first steps that lead to toxic red-tide algal blooms off Florida.
- Earth
EU moves against flame retardants
The European Union has provisionally voted to ban the use and importation of nearly all members of a family of flame retardants known as polybrominated diphenyl ethers.
- Earth
Where’s the smoke from the N.Y. fires?
Analyses of smoke from the destroyed World Trade Center towers indicated little risk that the fires would cause significant health effects for cleanup crews and city residents.
- Anthropology
Humans in eastern Asia show ancient roots
Human ancestors lived in northeastern Asia about 1.36 million years ago, making it the oldest confirmed occupation site in eastern Asia.
