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Earth May Have Been Hit By a Gamma-Ray Burst In 775 AD
The Bad Astronomer writes "Studies of carbon-14 in Japanese trees and beryllium-10 in Antarctic ice indicate the Earth was hit by a big radiation blast in 775 AD. Although very rare, occurring only once every million years or so, the most likely culprit is a gamma-ray burst, a cosmic explosion accompanying the birth of a black hole. While a big solar flare is still in the running, a GRB from merging neutron stars produces the ratio of carbon and beryllium observed, and also can explain why no bright explosion was seen at the time, and no supernova remnant is seen now."
Depends on intensity I imagine. The article notes it had to be further then 3000 light years away or they'd have expected it to cause an extinction event - and also that there are "short" and "long" GRBs.
But you not like earth when EARTH ANGRY! RAAWWWRR
Did we get struck twice in 775? I bet samzenpus knows.
http://news.slashdot.org/story/12/06/04/1147201/what-struck-earth-in-775
Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
I thought a nearby GRB would wipe out all life, all the way down to viruses.
It would. But if it was farther away, it would just create a bunch of radioactive isotopes in the upper atmosphere while leaving life on the ground mostly unmolested.
If only someone had an estimate of how far away this one was, and had presented it in something that would describe this news item in detail. We could call it an "article".
For non-douches who also didn't RTFA, it's estimated at 3000 to 13000 ly away. For comparison, in Phil's book "Death from the Skies" he discusses what would happen as a result of a GRB from 100 ly away, and the result is Very Bad(tm).
The enemies of Democracy are
They were really the Glow-In-The-Dark Ages.
FTA: "In the last 3000 years, the maximum age of trees alive today, only one such event appears to have taken place."
The actual oldest trees are about 5,000 (http://en.wikipedia.org/wiki/List_of_oldest_trees)
Though that doesn't devalidate his main point (that this has only happened once in 3,000 years). I just wish he'd fact-check a bit more.
Neither of the articles discuss what might have happened to living things at the time. Could some people have had radiation sickness for example? Could this have caused mutations?
http://michaelsmith.id.au
For comparison, in Phil's book "Death from the Skies" he discusses what would happen as a result of a GRB from 100 ly away, and the result is Very Bad(tm).
Of course for all the preppers out there it should also be said that the closest confirmed GRB is 1.3 billion light-years from Earth, the observation period isn't very long but it's hardly a common occurrence. Which is also why I'm a little sceptic that we've had one right on our doorstep only a few thousand light years away.
Live today, because you never know what tomorrow brings
http://en.wikipedia.org/wiki/774%E2%80%93775_radiation_burst
The part about witness accounts to a red cross like image in the sky, meaning someone may have actually seen the event...
I'd take that with a pinch of salt. I've been reading Tom Holland's "Millennium" and it mentions that one of the Holy Roman emperors (an Otto) was heading down to Jerusalem to hand his crown over to JC when he came down for the second coming, when the army he was with saw a dragon in the sky. They figured this was a portent of bad things, and weren't surprised when Otto died a few days later.
I wouldn't take that anecdote as evidence for dragons though.
"The greatest lesson in life is to know that even fools are right sometimes" - Winston Churchill
That's a bit of a backward way to approach it.
Normally, when we make observations that don't line up with our current understanding (e.g. "Where did all this carbon-14 come from?") we look for explanations. The most likely known sources of carbon-14 spike are GRB's and solar flares. Discounting those because the overall event is unlikely, in spite of the evidence, is what scientist dub "stupid".
also, couldnt a grb at worst wipe out life on just half the planet? Surely if you're on the "dark side of the earth" for this event, you would be safe.
Sure, if you can build the 40,000 km long, 30 km high wall around the terminator fast enough to prevent your part of atmosphere from getting spoiled with all the NO2 generated by the gamma burst interacting with the atmosphere.
Ezekiel 23:20
I would still call it an article if it just contained the word "the".
Definitely.
The enemies of Democracy are
Specifically... the risk of crashing into solid matter that doesn't emit or reflect light.
I see that you too own a black lab that sleeps between the bed and the bathroom...
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