Lava flows like these Hawaii’an ones are endlessly mesmerizing. This type of flow is gravity-driven; rather than being pushed by explosive pressure, the lava flows under its own weight and that of the lava upstream. In fact, fluid dynamicists refer to this kind of flow as a gravity current, a term also applied to avalanches, turbidity currents, and cold drafts that sneak under your door in the wintertime. How quickly these viscous flows spread depends on factors like the density and viscosity of the lava and on the volume of lava being released at the vent. As the lava cools, its viscosity increases rapidly, and an outer crust can solidify while molten lava continues to flow beneath. Be sure to check out the full video below for even more gorgeous views of lava.  (Image/video credit: J. Tarsen, source; via J. Hertzberg)
Neanderthals Fashioned 'Jewelry' Out of Animal Teeth and Shells
Some of the last Neanderthals to exist on Earth fashioned tiny beads out of animal teeth, shells and ivory before Neanderthals went extinct about 40,000 years ago, a new study finds.

About 42,000 years ago, the Neanderthals — the stocky cousins of modern humans — fashioned tiny jewelry beads from animal teeth, shells and ivory, a new study finds.

The finding is momentous, as it suggests that Neanderthals could engage in symbolic expression — the ability to make art — before they went extinct about 30,000 years ago, the researchers said.

“We now know that some of the last Neanderthals in Europe made artifacts that we do not see in Neanderthal material culture before that time,” said Frido Welker, the study’s lead researcher and a doctoral student of human evolution at the Max Planck Institute for Evolutionary Anthropology in Germany.

Continue Reading.