Free Republic

The settlement occupants left an abundant and continuous record of seeds, legumes and other foods...By studying these archaeological layers, Professor Kennett and colleagues were able to discern the types of plants that were being collected in the warmer, humid days before the climate changed and in the cooler, drier days after the onset of what we know now as the Younger Dryas cool period.Before the impact, the inhabitants' prehistoric diet involved wild legumes and wild-type grains, and small but significant amounts of wild fruits and berries.In the layers corresponding to the time after cooling, fruits and berries disappeared and their...

A team of researchers working at Argonne National Laboratory, in Illinois, has found a way to dramatically reduce friction between two macroscopic scale surfaces—to near zero. In their paper published in the journal Science, the team describes how they accidently discovered the method and why they believe it might be useful for real world applications. As most people are aware, friction causes energy loss and wear and tear on mechanical parts—lubricants such as oil are used to help reduce friction and to dissipate heat, but scientists would really like to find a way to prevent it from happening in the...

Enlarge Image Gem of a therapy? Clusters of nanodiamonds bearing chemotherapy drugs attack cancer cells. Credit: Science/AAAS If you give a nanodiamond to your fiancée, you can forget about the wedding. But a new study reports that these tiny flecks of carbon can shrink tumors in mice by delivering chemotherapy drugs to cancer cells. Lead author Dean Ho, a biomedical engineer at Northwestern University in Evanston, Illinois, says that one of the major challenges in chemotherapy is when tumor cells develop mechanisms to pump drugs right back out. But Ho reasoned that when the drug is bound to a...

Researchers have found shock-synthesized hexagonal diamonds on one of California's Channel Islands, which they say is the strongest evidence yet that a comet exploded in the atmosphere above North America, causing widespread extinctions there around 12,900 years ago... In 2007 researchers theorized that a comet set off continental fires that led to the mysterious disappearance of the Clovis people and the extermination of 35 mammal genera, including mammoths, mastodons, ground sloths and camels. The team documented a "black mat" of charcoal throughout North America that contains high levels of iridium, magnetic spheres, and nano-diamonds, which are consistent with such an...

Nanodiamonds found across North America suggest that major climate change could have been cosmically instigatedRoughly 12,900 years ago, massive global cooling kicked in abruptly, along with the end of the line for some 35 different mammal species, including the mammoth, as well as the so-called Clovis culture of prehistoric North Americans. Various theories have been proposed for the die-off, ranging from abrupt climate change to overhunting once humans were let loose on the wilds of North America. But now nanodiamonds found in the sediments from this time period point to an alternative: a massive explosion or explosions by a fragmentary...

Comet may have exploded over planet, causing fires, die-offs, researchers say A meteorite colliding with the Earth 65 million years ago is considered to be the most likely reason dinosaurs vanished from the planet. Now a team of scientists says it has found new evidence that an object from space caused a similar extinction event only 13,000 years ago. In an article to be published Friday in the journal Science, researchers present what one author calls the "smoking bullet"—proof that an exploding comet triggered the sudden, thousand-year freeze that killed off mammoths, saber-toothed tigers and other large mammals that used...