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Linking Mass Extinctions To the Sun's Journey In the Milky Way
schwit1 writes "In a paper published today on the Los Alamos astro-ph preprint service, astronomers propose that as many as eleven past extinction events can be linked to the Sun's passage through the spiral arms of the Milky Way. (You can download the paper here [pdf].) From the paper: 'A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events. Furthermore, we identify five additional historical mass extinction events that might be explained by the motion of the Sun around our Galaxy. These five additional significant drops in marine genera that we find include significant reductions in diversity at 415, 322, 300, 145 and 33 Myr ago. Our simulations indicate that the Sun has spent ~60% of its time passing through our Galaxy's various spiral arms.'"
Quoting: "Furthermore, we identify five additional historical mass extinction events that might be explained by the motion of the Sun around our Galaxy."
At best they have found a correlation in time. They surely have not found an explanation for the mass extinctions.
I only read the abstract, but while it proposes a correlation it did not speculate on the exact cause of the extinction. I wonder if passing 'nearer' (I use the term loosely) to higher concentrations of stars might disturb the Oort cloud, sending more comets than normal careening in towards the inner solar system ... or if we might catch stragglers from other stars' own Oort Clouds.
Assume it were possible to slingshot our sun out of the galaxy into intergalactic space. Would we be better off there, or does the Milky Way offer some sort of protection against whatever's out there (radiation, etc)?
Better known as 318230.
So if we are moving through spiral arms, and it appears our neighbouring stars appear 'relatively' fixed to our position does this mean that all stars in our galaxy move through the spiral arms? Do the spiral arms move w/respect to all the stars like some sorta density wave?
A man spends the first half of his life accumulating stuff, the second trying to get rid of it all.
All the tasty fish got eaten and overfished to extinction.
in other news...many people die in hospitals, therefore hospitals may cause death.
I ran an RPG where the world was moving through an interstellar dust cloud, complete with its own dark angels, rains of fire from the heavens, red coloured sun, all the trimmings. It rocked.
when are we due?
You can create a lot of correlations without any causation. the only way to validate the theory is to wait a few tens of millions of years.
Before you read too much into this report, remember that a preprint service makes papers available to researchers in the field before the paper has undergone the peer-review process. This allows the results to be circulated amongst other researchers quickly as the peer-review process can takes quite some time.
While not as bad as say having a press conference about discovering "Cold Fusion" before any peer-review only to find that the results could not be duplicated, take the papers contents with a grain of salt as the research has not been peer-reviewed.
You might think of it like the answers you get in the back of a textbook that have usually been done by an author's grad students. Most of them are probably correct, but nobody has gone over them with a fine-tooth comb to verify their correctness.
If the mainstream theory that the sun is internally powered by nuclear fusion is correct, then this hypothesis does not make much sense, but if the hypothesis that the sun is externally powered by electric currents flowing in the spiral arms of the galaxy, then that hypothesis MIGHT make some sense. As the sun and the entire solar system orbits the center of the galaxy, the strength of these currents certainly could fluctuate to affect the sun and earth in this way.
A sufficiently advanced simulation is indistinguishable from reality.
There has previously been a theory that these mass reoccurring extinctions would have been created by the near passing of a hypothetical star that we would have been unable to detect because it would be on the other side of the Oort cloud.
I suppose that this new finding will debunk that theory for good.
The hypothetical star had been named Nemesis. I know of it only because I ready about it in a novel by Asimov recently.
"We mustn't be caught by surprise by our own advancing technology" -- Aldous Huxley
Papers aren't published on the arXiv. The clue is in the name, which is even quoted in the summary: "pre-print server". It's an archive of papers before they're published.
Petty and irrelevant? That's me.
... is when we pass through the next one!
By Sir Arthur Conan Doyle
http://en.wikipedia.org/wiki/The_Poison_Belt
Government cannot make man richer, but it can make him poorer. - Ludwig von Mises
http://news.nationalgeographic.com/news/2007/04/070420-extinctions.html Other researchers found that time periods Earth is exposed to large amounts of cosmic rays is correlated with mass extinction events. This is a possible explanation.
I've got a novel by John Brunner written in 1982 called The Crucible of Time (), which documents a (very non-human) species through its scientific awakening. Throughout the book they're discovering that their planet is getting closer to a cloud of debris dense enough to massively devastate the surface, possibly shatter the planet. In the end they manage to build enough arks to save the species. The foreward reads:
"It is becoming more and more widely accepted that the Ice Ages coincide with the passage of the Solar System through the spiral arms of our galaxy. ..."
GStreamer - The only way to stream!
I'm sure I remember reading about this forever ago somewhere.
That as our solar system comes in and out of each belt, the amount of radiation generally increases as it clusters closer to the other stars that tend to follow the group speed, and equally as it bounces up and down in alignment with the galaxies average disk height where most stars occupy. (the latter being of lesser worry due to the fact that it increases much less compared to it catching up on the arms.)
It'd make sense as it would cause huge irregularities in most life due to the massive increases in radiation.
Generally it would tend to more life becoming immune or heavily protected against radiation, so if there was any evidence for that, it could likely be true.
Equally things like cancer would become more common, if there are species with very or even no incidences of it, may possibly be a link there. Most likely not though since cells losing control of themselves is far more complicated than just radiation, diet, chemical reactions and genetic screw-ups can all lead to it as well.
Even something as simple as punching someone at the wrong time could lead to a chain of reactions that results in it because something was crushed, or something was restricted long enough, or something got too much, all leading to a cell going haywire. You can literally punch someone in to cancer, wield it wisely my son.
But even the most well protected things could still easily get cancers by irradiating their intestine, they are horrifically sensitive to external radiation, always cover them if you are working with radioactive crap, and like what I am doing now, don't put hot water bags on them for long periods of time.
Comet extinctions could equally be the cause. Considerably more stone floating around the rings to explode like the Russian one just did, likely with far larger sizes and frequency. And that Oort cloud is just sitting out there. Doing nothing. Waiting. Stalking. He hungers.
Imagine a rock exploding every day above our skies, it would be a disaster, entire towns being damaged or wiped out, farms gone.
We'd probably end up having to live under ground at this point. Deep under ground. A stupid amount of safety systems in the corridors that connect us to the surface, a riddickulous amount of redundancy in so many systems to keep the cities working as well as to watch the outside to see if it is safe.
And that isn't even the worst part, once we emerge, we could literally die in a few minutes if some new awful strains of viruses and bacteria had evolved in that time, it'd take us a further few hundred years to ever fully get out of the cities as we slowly try to cure all of them once more.
Mind you, by the time this were to even happen, we'd probably be able to go punch Saturns balls. All of them. We'd most likely have mastered genetics by that time, or be perma-dust since we nuked ourselves to hell over petty spying issues and oil.
Sort of reminds me of that Stargate episode, but that was related to an asteroid ring rather than galaxy arm.
What's this "Los Alamos astro-ph preprint service" of which you speak? It's called arXiv. The old URL just redirects to the proper web site. It's been like that for about a decade.
From what I read in the paper, I don't think the summary is right. The paper abstract itself seems misleading, though, so maybe it's not the editors' fault this time.
You see, the researchers actually created a new model of the galaxy arms and sun's orbit around the galaxy core, different from the current one (well, they based the "original" on a bloody drawing, anyway). What did they use as evidence for their new model? Yes, you guessed right: the extinction events. The *made* it fit, they did not find a correlation. Here's their own conclusion:
"We created a new model of the Sun's orbit around the centre of the Milky Way, in order to accommodate the influence of spiral arm crossings on the cometary flux through the inner Solar system. Our model reveals the periods when the Earth has suffered the highest risk of cometary impacts -- periods that will likely span several million years, and be separated by periods of several tens of millions of years.
We have combined marine genera data, an orbital model of the Sun's path around the Milky Way with two face-on Galactic models. The first Galactic model is based on an artistic rendition of the Milky Way, by Churchwell et al. (2009). The second is an alteration of the first model, which accommodates all the extinctions within the spiral arms and displays a more symmetrical structure. Extinction data were then added to the new model and the existing orbital path of the Sun. In doing so all extinctions fall within the spiral arms."
Thought I recalled reading something about this in Death From The Skies and sure enough, from over four years ago, Death from the Spirals! Maybe not so much. Given its age, I especially liked the punchline...
Correlation is not causation, but correlation by itself does not rule out causation. Not sure why people have a tendency to discount that possibility. Is that an online thing, or does it happen in real life too?
A competing hypothesis tries to show a correlation between mass extinctions and the times when our solar system is farthest to the "north" of the galactic disk. I've always found that hypothesis tantalizing and somehow compelling even though it cannot explain the KT event. Presumably there can be more than one cause of mass extinctions.
Quite an experience to live in fear, isn't it? That's what it is to be a slave.
Well, given that any oncoming wave of asteroid/comet should also leave impressions on the Moon, let's establish a Moonbase by 2020 and look for correlations (amount many other things) there.
I just went and tried to read the research. I couldn't understand a word of it, but it probably means the Earth is going to be consumed in a fiery cataclysm.
Just my luck this would happen when the Bears are 2-0 and my fantasy team is in first place. Well, I guess it's time to run up the credit cards.
You are welcome on my lawn.
A technological regress requires a fragile society not just a sudden jolt.
But we are a fragile society. Without even having to bring up the Idiocracy, the fact remains that we're mostly a society of specialists, dependent on the other cogs in the machine for our survival, stupidly mocking the "preppers" who are really just trying to be generalists. A comet strike could easily disrupt this machine and cause it to grind to a halt.
"Once we've identified and embraced our sickness, we'll have strength...and that's when we get dangerous." - John Waters
"Without catastrophic or otherwise challenging events, life seems to become complacent - evolution often plateaus."
And this is a bad thing... exactly how?
I think Idiocracy did a pretty good job of explaining why it's a bad thing.
"Once we've identified and embraced our sickness, we'll have strength...and that's when we get dangerous." - John Waters
The Dust Lanes of our galaxy are easily visible to the naked eye. But I speculate that the dust particles have sizes up to planet sized particles. In my book, "Dust Lanes", the Earth is hit by walls of rock from a dust lane with a relative speed of 5000 miles per second.
Carl Icahn put out a nicely worded take on why CEOs only promote people who are less intelligent than themselves...
http://gradspeeches.com/2008/2008/carl-icahn
Problem right there:
"Our simulations indicate that the Sun has spent ~60% of its time passing through our Galaxy's various spiral arms."
But it hasn't spent either 60% or 40% of its time having extinction events, has it.
How do they model the arms on the far side of the galactic center? There's a bunch of dust, gas and other stars in the way, and I don't remember there being a Cosmic Mirror out there. So are we making assumptions based on other galaxies, or do we actually have data for the far side of the Milky Way? If it's assumed, then why should we get excited over correlations found in an assumed model? And what does God need with a starship??
Makes sense to me...there is more stuff to run into in the spiral arms than elsewhere. So when does our solar system wander through the next one?
In the quote from the top, I note that the end Permian mass extinction at 251 MYA and the K/T extinction at 65 MYA are not on the list. The first is the largest of the five largest ME's The one at 415 is on that top list as the Ordovician ME, which was less significant than the K/T one. It is the one for which a gamma ray burst has been proposed, which is controversial.
I haven't read the article, yet, but questions I would have concern how they define what the sun's motion in orbit around our galaxy encounters. Is it the crossing of the plane of the galaxy where problem objects might be more numerous or is it true spiral arms? I note the clustering of two events in the Carboniferous at 322 and 300 MYA, there is a major magmatic event in Siberia linked to those events and the massive erruption of the Siberain Trapps at 251 MYA has been implicated in the Permo-Triasic extinction. The sun takes about 150 MY to orbit the galaxy, so the authors would have to convince me that 1) they know the spiral arm configuration all the way around the galaxy and 2) that is it stable over 400+ MY. I might doubt that.
This story may be due to astronomers and physcists speculating about geologic and biologic events where alternative explanations are more likely. The geologic record in sediments and fossils for these events records changes in biota and changes in the chemistry of rocks, almost no direct evidence of an astrophysical nature. The Ir anomaly in the KT boundary is the sole exception. I am not sure what they might offer as evidence to look for. I assume that they would say the the earth would be a risk of encountering a nearby supernovae or gamma ray event. Would nearby energetic events leave something like different isotope ratios that can't be explaned by climate change?
Huh? Who was talking about the impact of losing a few specialities? I'm talking about a world where specialists have no value because the infrastructure isn't there to make use of them. You've completely missed the point.
And the other replies to your post are completely missing the point too. I'm not talking about going without high-tech hardware...I'm talking about going without FOOD. We can't go without food. And people wouldn't simply sit there and starve to death...they'll fight tooth and nail for the last scraps of food.
If being a prepper makes me crazy, I'm glad I'm not "sane" like you.
"Once we've identified and embraced our sickness, we'll have strength...and that's when we get dangerous." - John Waters