News
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PaleontologyRole of gastroliths in digestion questioned
New analyses of the gastroliths in ostriches are casting doubt on the theory that large, plant-eating dinosaurs swallowed stones to grind up tough vegetation and thereby aid their digestion.
By Sid Perkins -
PaleontologyTracks suggest chase, capture, and after-meal respite
A 1.3-meter-long, S-shaped trail of fossil footprints discovered in southwestern Indiana includes one set of disappearing tracks—suggesting an ancient chase—and an impression where the predator rested after its meal.
By Sid Perkins -
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PhysicsSuper Spinner: Seven-atom speck acts like superfluid
Scientists have for the first time directly observed the onset in liquid helium of superfluidity—a quantum-mechanical state in which liquids flow without friction—as helium atoms accumulated one by one to form a droplet of liquid around a gas molecule.