Uncategorized
- Astronomy
In the Beginning: Dark matter builds galaxies, feeds quasars
Cosmologists say they have found compelling evidence that massive galaxies were already in place when the universe was less than a billion years old.
- Paleontology
Wings Aplenty: Dinosaur species had feathered hind limbs
A team of Chinese paleontologists has discovered fossils of a small, feathered dinosaur that they say had four wings.
- Earth
Estrogens classified as carcinogens
The sex hormones known as steroidal estrogens, which are used in hormone-replacement therapies and birth control pills, have joined a government list of known human carcinogens.
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19170
Researchers’ conclusions in this article that there is a “need to revisit controversial claims about the health benefits and risks of bed sharing for babies” seem to me to miss the point. The health benefits and risks of any sleeping environment should be of concern. Focusing solely on bed sharing implies that crib use is […]
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Goodnight moon, hello Mom
A national study finds that about 13 percent of U.S. infants now routinely sleep in a bed with their mothers or other adults, intensifying interest in alleged health benefits and risks of bed sharing for babies.
- Astronomy
Sundancing
Astronomers have solved the mystery of why supergranules—enormous cells of turbulent, charged gas on the sun's surface—appear to move across the sun faster than the sun rotates.
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19161
You are usually pretty good at explaining things to those of us outside the hard sciences, but the speed of gravity? Speed of light OK, but what is the speed of gravity? Robert L. SchragNorth Carolina State UniversityRaleigh, N.C. An object with mass creates a gravitational field around itself. Imagine that the object moves; then, […]
- Physics
Clocking gravity
The first attempt to measure the speed of gravity finds it roughly equal to that of light, as expected, though not everyone agrees that the method used can actually measure gravity's speed.
- Earth
Contraceptive ring could pose risks after its disposal
Discarded vaginal contraceptive rings could interfere with fishes' reproduction by releasing estrogen into streams.
- Earth
Snow alga may be sizable carbon sink
A common microorganism that adds a reddish tinge to some patches of snow may be a significant consumer of planet-warming carbon dioxide.
- Health & Medicine
Do liver stem cells come from bone marrow?
Tests of liver tissue from people who've received liver or blood-marrow transplants show that stem cells in bone marrow can populate the liver as liver cells.
- Materials Science
Conch yields clues for future materials
A conch's tough, calcium carbonate shell resists fractures because a protein surrounds the mineral crystals throughout the shell.
