
Medieval Manuscript Gives Clue about Mysterious Radiation Spike...
Tree ring data indicates that sometime around 774 or 775 A.D., an intense burst of radiation hit the Earth. What was its source? Scientists were uncertain, but it was probably a supernova. Unfortunately, there were no re...
http://www.neatorama.com/2012/06/29/medieval-manuscript-gives-clue-about-mysterious-radiation-spike/