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Astronomers Investigating Unknown Object That Hit the Earth In 773 AD
KentuckyFC writes "In November 2012, a group of Japanese scientists discovered that the concentration of carbon-14 in Japanese cedar trees suddenly rose between 774 AD and 775 AD. Others have since found similar evidence and narrowed the date to 773 AD. Astronomers think this stuff must have come from space so now the quest is on to find the extraterrestrial culprit. Carbon-14 is continually generated in the atmosphere by cosmic rays hitting nitrogen atoms. But because carbon-14 is radioactive, it naturally decays back into nitrogen with a half-life of about 5700 years. This constant process of production and decay leaves the amount of carbon-14 in the atmosphere relatively constant at about one part in a trillion will be carbon-14. One possible reason for the increase is that the Sun belched a superflare our way, engulfing the planet in huge cloud of high energy protons. Recent calculations suggest this could happen once every 3000 years and so seems unlikely. Another possibility is a nearby supernova, which bathed the entire Solar System in additional cosmic rays. However, astronomers cannot see any likely candidates nearby and there are no historical observations of a supernova from that time. Yet another possibility is that a comet may have hit the Earth, dumping the extra carbon-14 in the atmosphere. But astronomers have ruled that out on the basis that a comet carrying enough carbon-14 must have been over 100 km in diameter and would surely have left other evidence such as an impact crater. So for the moment, astronomers are stumped."
Tree Rings, July 30, 2012.
"Recent calculations suggest this could happen once every 3000 years and so seems unlikely."
Why would it seem unlikely, that at some point 1300 years ago, an event calculated to happen every 3000 years actually happened?
There was indeed a "red crucifix" supernova found recently around 775 -- seems obviously the cause.
"There was a time when astronomers would have immediately ruled out this possibility as well. But last year, astrophysicists calculated that sun-like stars can produce superflares of this size about once every 3000 years."
I think that if an event happened 14 centuries ago, and one explanation is supposed to happen every 30 centuries or so then it isn't something that can be discarded as an explanation without further evidence.
While we're arguing about solar flares, or supernovas, we're kind of ignoring the obvious. The title states "an unknown object" "hit the earth". That, also, is ruled out right in the article.
Maybe a better title would have been "Some shit happened in 773 AD and no one really knows what it is, but here's what we have so far!"
Read this, already published here like a year ago (o more):
http://phys.org/news/2012-06-red-crucifix-sighting-supernova.html
Good thing you brought it here. Nothing solves a mystery faster than wild ass conjecture.
At the simplest level, you can assume that C14 is constant, but the question of is it constant or not has long ago been addressed. Using just tree rings for example, you can match up rings from past dead trees as they tend to be of similar size in years with good weather and smaller in years of bad weather, and records of wood going back thousands of years can be created. This gives a way of testing for C14 levels going back a long time, and yields corrections for dates on the order of 10% from the naive assumption that C14 levels don't change. In addition to tree rings, carbon trapped by other processes and in historical artifacts also shows close agreement, and carbon trapped in some mineral formations allow for a comparison between carbon dating and other radiocarbon dating. So there is a standard calibration graph produced by all of this to convert naive, constant C14 years into actual calibrated years (it also includes a 3% correction to the half life of C14 found in the 60s). ;
If you really want to get into the details of this, you can find information that deals with the chemical differences between C14 and C12, which is pretty slight. Depending on if a plant is C3, C$ or CAM photosynthesis based, it will absorb C14 at slightly different rates, and the absorption into the ocean is delayed from the atmosphere due to how slow it takes to mix the whole volume, and chemistry for incorporating C14 into things like shells is different than from that of photosynthesis slightly. But at that point, the differences are pretty small. You can look at the carbon isotopes in something modern, created less than a year ago like honey, and still struggle to tell if it is "real honey" made from typical C3 plants or had additional sugar from a C4 plant like corn unless it was above a 10% level.
Yes, once the plant dies, the C14 is locked in and starts decaying. But A.C. was asking about the atmosphere -- isn't that supposed to be constant?
It's not quite constant, for various reasons listed here:
http://en.wikipedia.org/wiki/R...
The answer is to calibrate against something organic with a known age. Tree rings, which can give you a whole series of data points, are perfect for this.
Future archaeologists may be puzzled by the anomalous atmospheric levels of C14 in the mid 1960s, which were nearly double the normal levels (thanks to the radiation from above-ground nuclear weapon testing converting more N14 than usual). Contrary to the pop science picture, not all of the atoms in your body are replaced every 7 years and (e.g.) the DNA in certain long-lived brain cells of people born in this era still contains elevated levels of C14. In fact, it's thanks to the nuclear powers effectively doing an isotopic labelling experiment on the entire biosphere that we know the age of these cells in the first place.
But astronomers have ruled that out on the basis that a comet carrying enough carbon-14 must have been over 100 km in diameter and would surely have left other evidence such as an impact crater... ... or perhaps the complete extinction of every living thing on the planet.
In 772, Charlemagne began a war of extermination against the heathen Saxons, destroying the Irminsul, the chief seat of their religion. Santa Claus (known as Odin at that time, later Sinterklaus, then Santa) observed this, and at the end of 772, delivered elf-coal, high in carbon-14, to everyone in Charlemagne's forces. In the process, coal dust flew in unprecedented amounts from his sleigh, and this was naturally absorbed by the trees during 773.
I swear, if you people just knew your history a little better, you could maybe make this "science" stuff work better.
I've fallen off your lawn, and I can't get up.
One possible reason for the increase is that the Sun belched a superflare our way, engulfing the planet in huge cloud of high energy protons.
...and it could just be God, testing our faith. We learn from presentations at The Creation Museum that God does this all the time, putting riddles into nature to show us that we aren't all smart and sciency like we think we are. He could totally make a giant space gun that shoots high-energy protons at certain places in the earth to make it look like something happened a long time ago, just like he made it look like the dinosaurs lived way before Adam and Eve.
I'm looking at Google Earth right now, just give me a few minutes ill find the impact lol
Jack of all trades,master of none