What The Hell Happened in 775 AD ????

[Sionyn]

What The Hell Happened in 775 AD ?

A study of trees that were growing over 1,000 years ago has revealed that an intense burst of radiation hit the Earth in around 775AD.

Researchers at Nagoya University in Japan measured the amount of carbon-14 (C-14) in Japanese cedar trees. C-14 is a radioactive isotope produced when radiation from space hits atoms in the atmosphere, producing neutrons. These then hit nitrogen-14, which decays to C-14. Tree rings that grew just over 1,200 years ago show a 1.2 per cent rise in C-14 - around 20 times greater than the typical event variations.

This event caused an increase in the concentration of carbon-14 in the atmosphere of about 1.2%. That's apparently about 20 times the normal rate of variation, but the baseline level of carbon-14 is about a part per trillion, so we'd be talking about increasing the concentration of carbon-14 by about 10 parts per quadrillion. In contrast, the period of above-ground nuclear testing almost doubled the concentration at its peak in the early 1960s. it's unknown whether other radiological hazards would have been present in addition to the C14 spike, but there don't seem to be indications of mass dieoffs or famines.

The 774–775 carbon-14 spike was an increase of 1.2% in the carbon-14 content of tree rings during the years AD 774 or 775, which was about 20 times higher than the normal rate of variation. It was found during a study of Japanese cedar trees, with the year of occurrence determined through dendrochronology.  A surge in a specific isotope of beryllium, detected in ice cores of Antarctica, has been associated with the 774-75 event..

It is hypothesized to have been the result of a cosmic ray event, or radiation burst. Carbon-14 can be formed as a result of gamma rays from supernovas or proton storms from solar flares; however, the origin and nature of the event does not appear to be related to either of these, and remains a mystery. No supernova was recorded in that time frame, and even an unobserved supernova would have been expected to produce a supernova remnant that would be observable today. A very major solar flare would have produced remarkable auroras, of which there is no record, or drastically affected the ozone layer, with major biological or ecological consequences, for which there is no evidence. It has been suggested that a short gamma-ray burst, which is not associated with a supernova, may have been responsible.

or maybe the flying spaghetti monster was up to something. or maybe dave has a time machine

http://www.slate.com/blogs/bad_astronomy/2013/01/21/earth_hit_by_a_gamma_ray_burst_did_a_cosmic_blast_hit_us_in_775_ad.html

[SoftwareSamurai]

Uh, maybe the Sun burped at the Earth?   

[G7PSK]

I read that it was due to two black holes colliding at the center of the galaxy. But there have been several cases of natural uranium achieving critical mass over the course of the Earths history.