8th century gamma ray burst irradiated the Earth, study finds

(Phys.org)—A nearby short duration gamma-ray burst may be the cause of an intense blast of high-energy radiation that hit the Earth in the 8th century, according to new research led by astronomers Valeri Hambaryan and Ralph ...

Red Crucifix sighting in 774 may have been supernova

(Phys.org) -- A supernova may have actually been the mysterious "Red Crucifix" in the sky that is cited in the Anglo Saxon Chronicle for the year 774. New correspondence between a university student and Nature carries interesting ...

Climate change caused empire's fall, tree rings reveal

(Phys.org) —A handful of tree ring samples stored in an old cigar box have shed unexpected light on the ancient world, thanks to research by archaeologist Sturt Manning and collaborators at Cornell, Arizona, Chicago, Oxford ...

Radiocarbon dating gets a postmodern makeover

For decades, radiocarbon dating has been a way for scientists to get a rough picture of when once-living stuff lived. The method has been revolutionary and remains one of the most commonly used dating methods to study the ...

Rings reveal extensive yearly climate record

A new study of the oldest trees in Mexico provides the first ever detailed, year-by-year look at the climate of Mesoamerica over a thousand-year span. The data, gathered from the annual growth rings in trees, supplies precise ...

New study upends timeline of Iroquoian history

New research by an international team raises questions about the timing and nature of early interactions between indigenous people and Europeans in North America.

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