News
- Physics
Radioactive sprinkles keep machines true
Needing tiny radioactive sources to calibrate medical scanners with ever-sharper vision, an Australian team dipped tiny balls the size of candy sprinkles into a radioactive liquid.
- Earth
Lowering the Boom? Impact crater may predate extinction of the dinosaurs
Analyses of sediments from the Yucatán in Mexico suggest that an extraterrestrial impact there more than 65 million years ago actually happened about 300,000 years before mass extinctions of dinosaurs occurred.
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Worst of Two Worlds: Hybrid mosquitoes spread West Nile virus
Interbreeding between two Old World mosquito species may explain why their blood-sucking brethren in the United States transmit West Nile virus to people as readily as they do.
