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Linking Mass Extinctions To the Sun's Journey In the Milky Way

timothy posted 1 year,8 days | from the arms-are-for-hugging-and-mass-extinction dept.

Space 199

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.'"

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Rubish (0)

Anonymous Coward | 1 year,8 days | (#44913057)

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.

Re:Rubish (4, Insightful)

Dutchmaan (442553) | 1 year,8 days | (#44913089)

**might** be explained

Isn't that pretty much what "correlation" means?

Re:Rubish (0)

Anonymous Coward | 1 year,8 days | (#44913113)

That's not what correlation means. Correlation refers to the speed one attains from grasping popularity, but individuals incapable of stopping the destruction of the dining quarters are not worthy of such a thing, so they cannot even hope to comprehend it.

Re:Rubish (5, Funny)

Anonymous Coward | 1 year,8 days | (#44913121)

It means every time a mass extinction occurs on Earth, a galactic spiral arm is contructed.

Re:Rubish (4, Insightful)

Dutchmaan (442553) | 1 year,8 days | (#44913171)

I know that's supposed to be tongue in cheek, but correlation is just another way of saying, we need to look into this with more detail. So if that's your hypothesis and there's correlation between the events, then who am I to judge if you decided to study it with greater detail.

Re:Rubish (0)

Anonymous Coward | 1 year,8 days | (#44913561)

"Every time a mass extinction occurs on Earth, a galactic spiral arm is constructed," and when the final mass extinction occurs on Earth, the only thing that gets constructed is a lousy Vogon hyperspace bypass?

Re:Rubish (2)

Teancum (67324) | 1 year,8 days | (#44913189)

It means every time a mass extinction occurs on Earth, a galactic spiral arm is contructed.

This sounds very reasonable to me, especially if it is just a "correlation".

Re:Rubish (1)

Anonymous Coward | 1 year,8 days | (#44913165)

No. "might explain" implies a direction, nominating the transitions as the possible cause for the extinctions. Now obviously, there will not a a link in the other direction. But this still leaves the possibility that there is no link. Besides, even if there is a link, this does not really *explain* the extinctions until a mechanism is proposed/proven.

Given the inaccuracies on such measurements, there is no proof of correlation. The only thing they can claim is that they see an "alignment" in time between one type of event and another type of event at a totally different scale. This might still be coincidence (11 extinctions spread over several billion years, where even the authors admit that they see two different groups of 6 and 5 each.).

Re:Rubish (1, Funny)

Anonymous Coward | 1 year,8 days | (#44913163)

It's clearly global warming caused by man that has lead to these mass extinctions.

Re:Rubish (3, Funny)

MightyYar (622222) | 1 year,8 days | (#44914055)

You laugh, but in 50 years the atmosphere gets so hot that it excites the molecules to light speed, at which point it creates a rift in space time that tears back through time, sending hot jets of atmospheric gases ripping through the atmosphere and extinguishing life at periods in the past.

Also, the midwest will be completely covered in 200ft of popcorn.

Re:Rubish (4, Insightful)

wonkey_monkey (2592601) | 1 year,8 days | (#44913221)

So why are you calling it "rubbish?" They've found a correlation. That's interesting. No-one's claiming to have discovered the mechanism. Correlation is not causation. You seem to have inferred that because someone's found a correlation, they must also be claiming causation.

Re:Rubish (0)

Anonymous Coward | 1 year,8 days | (#44913359)

Pseudosceptics are pathological and hate new discoveries and inventions, because they're unable to come up with them by being so narrow-minded!

Re:Rubish (1)

Anonymous Coward | 1 year,8 days | (#44913367)

Because correlation is not causation and because they use the word "explain" Nothing has been explained.

The proper way to report on this would be to say that these extinctions "(appear to) coincide with ..." and that this may be sufficient ground for further investigation,

Re:Rubish (4, Insightful)

Teancum (67324) | 1 year,8 days | (#44913557)

We use the most up to date Milky Way model and solar orbit data
in order to test the hypothesis that the Sun's galactic spiral arm crossings cause
mass extinction events on Earth.

That is how the authors of this paper reported their findings in the actual article's abstract. As for how some random Slashdot poster reported this idea, does it really matter? If you are complaining about Slashdot itself and lame editorship on the part of those who review these stories on the Slashdot staff, that is something else entirely and not something to complain about to the paper's authors.

Besides, they claim it is a causation, or that events which somehow happen during those crossings in turn trigger these extinction events. Unfortunately we have a data sample of one solar system to compare against right now to see if there might be any substance to the mechanism.

Re:Rubish (0)

Anonymous Coward | 1 year,8 days | (#44913585)

So you are not criticizing their findings but instead their writing? This minor difference in writing opinion and style has enraged you to the point of calling the entire work 'Rubish' with such haste that you managed to spell the word wrong.

Re:Rubish (5, Interesting)

hairyfeet (841228) | 1 year,8 days | (#44913563)

Well I'm not a scientist but with a little common sense being applied and knowing what we know it makes sense. After all what do we know so far? Well we know there is this HUGE band of rock at the outer edge of our system called the Oort Cloud, there is also another huge band of rocks in the inner system which may have been a failed planet. If going through the arm caused changes to the gravitational fields way out there in the oort cloud it probably wouldn't take much to get one of those chunks moving, after all that is where it is believed all our long term comets came from so there had to be something in the past that got the comets going. So if you look at how big a period we are looking at and how much debris we have in the inner belt the idea that going through the arm may occasionally cause one of those big inner rocks to get flung at us,possibly by being hit by something fling out of the oort? Really doesn't sound too implausible to me.

To me the thing I find really interesting is how many times our friend Mr Jupiter has saved us by being a big giant garbage collector and pulling all this crap into it that could have easily headed our way if it wasn't there. i honestly wouldn't be surprised if it turned out for every extinction event there was probably thousands that didn't happen because Jupiter sucked it up or slung it off in another direction,given how many times we have seen impacts in just the little bit of time we've been able to see that far out.

So I wish them all the luck, maybe if we can find out exactly what events cause these maybe we can avoid it happening to us, as while I doubt we'd see 100% fatalities of the human race one really nasty impact could easily send us back to the dark ages.

Re:Rubish (2)

jbolden (176878) | 1 year,8 days | (#44913623)

one really nasty impact could easily send us back to the dark ages.

I agree with everything you wrote till this. Obviously a huge sub planet sized object and we are done. But something like a comet a few miles across how would that cause technological collapse planet wide? Lose 1/2 or 2/3rds of the population wouldn't do that. A technological regress requires a fragile society not just a sudden jolt.

Re:Rubish (2)

Progman3K (515744) | 1 year,8 days | (#44914007)

I agree with you that there are probably gravitational perturbations to the Oort cloud or inner asteroid-belt that result in extinction-events but I also expect that there is another phenomena: the varying levels of cosmic rays as we pass through the galaxy's arms.

Re:Rubish (2)

Impy the Impiuos Imp (442658) | 1 year,8 days | (#44913577)

A real test would be to use such transitions to look for another one not associated with any mass extinctions, and then go look if one actually happened.

I don't know if such would have lain undiscovered so far, but it would make for a good predictive test.

Re:Rubish (4, Interesting)

meerling (1487879) | 1 year,8 days | (#44913737)

It's been brought up before, and rather quickly debunked, not because a number of extinctions do occur at the periods of crossing a galactic arm, but rather the numerous other times when extinctions occur outside of the galactic arms, and the times it passes through the arms that the extinction events don't occur.

If you want to see what I'm talking about, just search the science sites about it.

Yes, it is an intriguing idea, but No, it doesn't hold up to scrutiny.

Re:Rubish (1)

Pino Grigio (2232472) | 1 year,8 days | (#44914123)

Mod Up. I remember reading about this when I was an undergrad 20 years ago. It's not a new hypothesis.

Re:Rubish (0)

Anonymous Coward | 1 year,8 days | (#44914237)

This debate reminds me of an old xkcd [xkcd.com] ...

Re:Rubish (2)

osu-neko (2604) | 1 year,8 days | (#44913381)

At best they have found a correlation in time.

So, you're saying they've found precisely what they claimed to have found -- a correlation.

Explanation is elsewhere (4, Informative)

monatomic (2612833) | 1 year,8 days | (#44913509)

http://news.nationalgeographic.com/news/2007/04/070420-extinctions.html [nationalgeographic.com] 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.

Re:Explanation is elsewhere (2, Insightful)

ColdWetDog (752185) | 1 year,8 days | (#44913649)

I'm getting worried here.

Spiral galaxy arm transits.
Cosmic ray fluctuations.
Killer Asteroids.

I think somebody out there doesn't like us much (not that I blame them).

Re:Explanation is elsewhere (1)

chill (34294) | 1 year,8 days | (#44913811)

So, God wants to play at being Michael Bay?

Oort cloud? (5, Interesting)

Anonymous Coward | 1 year,8 days | (#44913065)

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.

Re:Oort cloud? (4, Interesting)

icebike (68054) | 1 year,8 days | (#44913223)

That is how I read it, or simply wandering comets, asteroids, broken free of what ever they were orbiting. Even interstellar dust concentrations perturbing our own asteroids might be enough.

But I was more surprised to learn the Sun was not traveling in rough unison with a (relatively) fixed spiral arm. Is this normal for all stars?
If all stars are wandering why do spiral arms exist at all? Why wouldn't the Milky Way simply be a disk?

Re:Oort cloud? (3, Interesting)

TapeCutter (624760) | 1 year,8 days | (#44913253)

Spiral arms are shock waves. The stars themselves don't move with the wave, they are created by it.

Re:Oort cloud? (3, Insightful)

icebike (68054) | 1 year,8 days | (#44913333)

Ah, such clarity.

Have you told those clowns at Harvard [harvard.edu] about this?

Re:Oort cloud? (2)

Chuckstar (799005) | 1 year,8 days | (#44913603)

The Harvard article in no way contradicts what TapeCutter said. Please clarify your point.

Re:Oort cloud? (4, Interesting)

icebike (68054) | 1 year,8 days | (#44913857)

“We find they are forming spiral arms,” explains D’Onghia. “Past theory held the arms would go away with the perturbations removed, but we see that (once formed) the arms self-perpetuate, even when the perturbations are removed. It proves that once the arms are generated through these clouds, they can exist on their own through (the influence of) gravity, even in the extreme when the perturbations are no longer there.”

No mention of Shock waves, or even a hint of what might cause such shock, or how such shock could be transmitted in the vacuum of space.

Density waves, (shock waves) another term for Stochastic Star Formation theory, is no longer the leading theory of the existence of spiral arms. Its not the 1960s any more.

This shock wave theory suggest that stars are relatively uniformly distributed, even in the inter-arm gaps, but because of density waves inducing star birth at their leading edge and star death at their trailing edge, the arms simply appear brighter.
Hubble pretty much put that theory to bed. see http://en.wikipedia.org/wiki/NGC_1300 [wikipedia.org] The inter-arm gaps are real.

Further the so called shock wave theory (Stochastic Star Formation) postulates that stars on average do not actually leave their "arm", and the visual effect of the arm at any give place pretty much spans the life of a star. (born on the leading edge, dead by the trailing edge). Yet this story suggests the Sun has wandered through the arm(s) several times.

Further, even when perturbations from a passing galaxy might have triggered them via gravity, the arms persist. and in some galaxies even after
the perturbations disappear. So what is driving these? What would cause "shock waves"?

The 60's are calling, and they want their theory back.

Re:Oort cloud? (4, Informative)

dkf (304284) | 1 year,8 days | (#44914173)

No mention of Shock waves, or even a hint of what might cause such shock, or how such shock could be transmitted in the vacuum of space.

Via the interstellar medium [wikipedia.org] , of course. It's pretty tenuous, but most certainly is capable of sustaining phenomena like shock waves. Which isn't to say that that's necessarily the particular process that is dominant in the galactic arms; it could also be something relating to magnetism, as the physics of a flowing magnetically-coupled medium is viciously difficult to work with (i.e., highly non-linear). And I've got no idea what happens at the phase change boundaries between the parts of the ISM which are plasmas and the parts which are conventional (tenuous) gasses; phase changes can do "interesting" things.

As for what's powering it all, you've got some exceptionally powerful energy sources out there. Black holes in particular can pump vast amounts of energy into the surrounding volume of space. The stellar wind from very high mass stars would be another interesting source.

Re:Oort cloud? (3, Interesting)

wulfhere (94308) | 1 year,8 days | (#44913281)

Man, do I wish for mod points. I was thinking the exact same thing about our star wandering. If the spiral arms are hostile to life, that could *significantly* cut down on the number of stars capable of supporting life.

Re:Oort cloud? (2)

symbolset (646467) | 1 year,8 days | (#44913455)

Mass extinction events are not hostile to life. They may in fact be essential to evolution.

Re:Oort cloud? (0)

Anonymous Coward | 1 year,8 days | (#44913643)

The spiral arm is not a fixed structure, rather it is a high density wave, similar to how you get fast and slow regions in a highway. This is way it's possible for the spiral arms to rotate slower than orbit velocity, it's not a real physical thing but just an emergent pattern.

Re:Oort cloud? (1)

icebike (68054) | 1 year,8 days | (#44913675)

You say that, but provide no evidence.

Re:Oort cloud? (0)

Anonymous Coward | 1 year,8 days | (#44913799)

The evidence is your eyes, clearly if they were a physical structure they would wind up very quickly because the inner stars orbit the galaxy much more quickly than the outer. But here's a link since since you asked so nicely. http://burro.cwru.edu/Academics/Astr222/Galaxies/Spiral/spiral.html, although clearly you already know what a density wave is.

Re:Oort cloud? (1)

icebike (68054) | 1 year,8 days | (#44913863)

They do wind up.
Don't tell me you are still thinking in terms of fixed radial arms?

Re:Oort cloud? (3, Informative)

symbolset (646467) | 1 year,8 days | (#44913275)

In the paper this is diiscussed as one possible explanation.

Such encounters would not pose a di- rect hazard to life on Earth by changing the orbit of the Earth around the Sun, but could pose a haz- ard by disturbing the Oort Cloud

Intergalactic space (3, Interesting)

Dan East (318230) | 1 year,8 days | (#44913107)

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)?

Re:Intergalactic space (1)

Anonymous Coward | 1 year,8 days | (#44913131)

But intergalactic space is the perfect place to hide a black hole!

Re:Intergalactic space (1)

icebike (68054) | 1 year,8 days | (#44913239)

You mean as opposed to Galaxies, which are free of black holes [einstein-online.info] ?

Re:Intergalactic space (2, Funny)

Anonymous Coward | 1 year,8 days | (#44913403)

No, no, no. I'm just saying that there's no way to detect a black hole without any matter around for it to consume. We're much safer where we can see them!
Won't someone please think on the children?

Re:Intergalactic space (2)

mrclisdue (1321513) | 1 year,8 days | (#44913985)

...Won't someone please think on the children?

A single typo, and suddenly you're on a few hundred watchlists....

Re:Intergalactic space (0)

Anonymous Coward | 1 year,8 days | (#44914245)

How long do black holes exist without anything to eat?

Re:Intergalactic space (1)

pixelpusher220 (529617) | 1 year,8 days | (#44914449)

I'm just saying that there's no way to detect a black hole without any matter around for it to consume.

Incorrect. We can detect dormant black holes through lensing [wikipedia.org] as they pass in front of stars and galaxies. If we're in inter-galactic space then stars will be fewer but there's quite a few galaxies to still detect them with.

Re:Intergalactic space (1)

Anonymous Coward | 1 year,8 days | (#44913173)

Protection against the boredom of a sky without stars . . .

Re:Intergalactic space (3, Funny)

AlphaWolf_HK (692722) | 1 year,8 days | (#44913183)

The reapers hide in intergalactic space, so we're probably not safe there.

Re:Intergalactic space (2)

TeknoHog (164938) | 1 year,8 days | (#44913445)

Surely you mean reavers [wikipedia.org] ?

Re:Intergalactic space (1)

Anonymous Coward | 1 year,8 days | (#44913575)

I think he meant the reapers [wikia.com] , since the reavers don't hide in intergalactic space.

Re:Intergalactic space (1)

MrBandersnatch (544818) | 1 year,8 days | (#44913535)

Peter F Hamilton if I recall but I can't remember the book/series...

Re:Intergalactic space (1)

NeoMorphy (576507) | 1 year,8 days | (#44914057)

Commonwealth Saga?

Re:Intergalactic space (1)

Teancum (67324) | 1 year,8 days | (#44913217)

It could be worse.... we could simply be falling into the galactic core and passing within a few light years of the central galactic black hole every few million years. Instead, the orbit of the Sun is roughly circular and stays in the main galactic disk.

The other possibility is that the Earth could fly into intergalactic space and the Sun could go in a different direction. That would make things very comfortable.

Re:Intergalactic space (0)

Anonymous Coward | 1 year,8 days | (#44913727)

The other possibility is that the Earth could fly into intergalactic space and the Sun could go in a different direction. That would make things very comfortable.

Surely you meant uncomfortable.

Re:Intergalactic space (1)

wjcofkc (964165) | 1 year,8 days | (#44913443)

An interesting thought. I suggest you read The Black Destroyer by A. E. van Vogt.

Re:Intergalactic space (4, Interesting)

symbolset (646467) | 1 year,8 days | (#44913489)

It is possible for the Sun to be flung out of the galaxy by passing too close to a much larger star. Stars are flung out of galaxies quite frequently in much the same way that asteroids and comets are frequently flung out of the solar system. The Earth would be unlikely to survive such an event. But if it did, no, there is nothing out there between galaxies that is more harmful than whirling through this relatively dense dust and grit.

spiral arms? (2)

freeasinrealale (928218) | 1 year,8 days | (#44913111)

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?

Re:spiral arms? (0)

Anonymous Coward | 1 year,8 days | (#44913127)

"some sorta density wave"

If only astrophysicists would adopt such terminology, our understanding of the universe would be much more widely understood... sorta!

Re:spiral arms? (0)

Anonymous Coward | 1 year,8 days | (#44913195)

Density waves are the current theory of spiral arm galaxy formation ( at least they were when I took astronomy in college)

Re:spiral arms? (1)

wonkey_monkey (2592601) | 1 year,8 days | (#44913229)

Pretty much, yeah.

Re:spiral arms? (2)

icebike (68054) | 1 year,8 days | (#44913269)

That was also my question.

Is this movement along the plane of the galaxy's disk, or oscillating above and below the disk? How sure are we that there even are spiral arms? If there were arms, then why would be be traveling through them, instead of with them? Why would an orbiting star system travel faster than other star systems in its proximity, and still remain in the same orbit?

Re:spiral arms? (0)

Anonymous Coward | 1 year,8 days | (#44913569)

we don't travel with the spiral arms because they are basically shockwaves - changes in density that travel through the galaxy. in the denser pars of this wave more stars are forming and that's why the arms appear brighter.

Re:spiral arms? (3, Informative)

bill_mcgonigle (4333) | 1 year,8 days | (#44913889)

Yeah, it wasn't clear from TFS or TFA what they were talking about, but further down in the discussion:

TL;DR: the Sun orbits the galaxy faster than the spiral arms, and when the solar system passes through gas clouds in the spiral arms, that can send more Ort-cloud comets at the Earth.

The motion of the spiral arms around the cen-
tre of the Galaxy is somewhat slower than that of the
stars that make up the galaxy, which means that, as
the Sun orbits the centre of the Galaxy, it follows
a path that takes it through the spiral arms every
few tens of millions of years. In the spiral arm envi-
ronment, the Solar System is exposed to a far more
hazardous and busy regime than in the inter-arm re-
gions (our current location). The Earth could be
relatively close to a star when its life comes to an
end in a supernova explosion { which could certainly
pose problems for life, although such supernovae are
relatively rare, and the odds of the Earth being suf-
ciently close to one for life to be exterminated en-
tirely are low, even within a spiral arm (Beech 2011).
At the same time, close encounters between the Sun
and neighbouring stars become more frequent, as do
encounters between the Sun and giant gas clouds
(see Fig. 2). Such encounters would not pose a di-
rect hazard to life on Earth by changing the orbit
of the Earth around the Sun, but could pose a haz-
ard by disturbing the Oort Cloud (Porto de Mello et
al. 2009), a vast cloud of comets (Oort 1950) which
stretches to a distance of at least 100 000 AU from
the Sun. The Oort Cloud is thought to contain tril-
lions of cometary nuclei, left over from the formation
of the Solar system, which are only tenuously grav-
itationally bound to the Sun (the outer members of
the cloud are around halfway to the nearest star).
An encounter with a passing star or distant molec-
ular cloud can be enough to deflect an Oort cloud
comet, throwing it onto a new orbit that will bring
it into the inner Solar system { where it can pose a
threat to the Earth. The closer the star approaches
to the Sun, or the more massive it is (or both), the
more comets it will scatter inwards, and therefore
the more likely it will be that one of those in-falling
comets will hit the Earth.

Re:spiral arms? (4, Interesting)

richard.cs (1062366) | 1 year,8 days | (#44913591)

Do the spiral arms move w/respect to all the stars like some sorta density wave?

That's exactly what the spiral arms are, they can't be the same stars orbiting together in that shape as that would imply a rigid body rotation. The situation where everything moves around together as if it were nailed to a rigid cosmic disc doesn't work because the orbit time of the stars at the centre of the galaxy is less than that of the stars at the edge. This is a consequence of the orbital physics, it's essentially the only way the forces can balance.

So, the stars in the centre whiz around quickly (in cosmological time anyway) whilst the ones at the edge take forever. The spirals are simply areas of higher star density but they are not the same stars all the time. This region does rotate but more slowly than the stars contained within it. So, why are there areas of increased star density? No-one's entirely sure but it seems likely that these are actually regions with higher rates of star formation, with many young, short-lived blue stars.

Alien fishing expeditions (1)

Anonymous Coward | 1 year,8 days | (#44913143)

All the tasty fish got eaten and overfished to extinction.

suuuure (0)

Anonymous Coward | 1 year,8 days | (#44913145)

in other news...many people die in hospitals, therefore hospitals may cause death.

Re:suuuure (1, Insightful)

wonkey_monkey (2592601) | 1 year,8 days | (#44913231)

So you're saying mass extinctions cause spiral arms? Interesting.

Re:suuuure (2)

FudRucker (866063) | 1 year,8 days | (#44913337)

wacky waving inflatable arm flailing tubeman!!!

Re:suuuure (0)

Anonymous Coward | 1 year,8 days | (#44914353)

His noodly appendages both sow and reap....

Re:suuuure (5, Insightful)

icebike (68054) | 1 year,8 days | (#44913311)

in other news...many people die in hospitals, therefore hospitals may cause death.

And indeed they do.

http://www.health-care-reform.net/causedeath.htm [health-care-reform.net]
http://en.wikipedia.org/wiki/Hospital-acquired_infection [wikipedia.org]

So don't be so quick to dismiss the possibility of causation, simply because it was discovered by correlation.
Falsely assuming no-causation is every bit as much as a statistics induced error as falsely assuming causation.

With correlation you have a reason to look for causation. Without correlation, looking for causation is just shooting in the dark.

Correlation does not rule out causation (2)

mveloso (325617) | 1 year,8 days | (#44913837)

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?

Re:Correlation does not rule out causation (1)

icebike (68054) | 1 year,8 days | (#44913903)

I think its a Slashdot thing, usually mentioned by the same people who talk in terms of Gravity Wells, and such.

Yeah (0, Offtopic)

Intrepid imaginaut (1970940) | 1 year,8 days | (#44913159)

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.

Re:Yeah (0)

Intrepid imaginaut (1970940) | 1 year,8 days | (#44913241)

How is this offtopic, it's a mathematical simulation of exactly the event described in the summary transposed onto a fictional game world. RPGs aren't WoW champ.

So... (0)

Anonymous Coward | 1 year,8 days | (#44913233)

when are we due?

Re:So... (1)

symbolset (646467) | 1 year,8 days | (#44913519)

About 100MY for a big one.

Re:So... (1)

chill (34294) | 1 year,8 days | (#44913825)

Are you sure it ins't closer to next Tuesday? I could swear that man on television asking me to send him money said it was next Tuesday.

Re:So... (1)

Anonymous Coward | 1 year,8 days | (#44914329)

...man on television...

He can't be a man, 'cause he doesn't smoke the same cigarettes as me.

If you have enough data (0)

Anonymous Coward | 1 year,8 days | (#44913259)

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.

"Published on a Preprint Service"... (3, Insightful)

Anonymous Coward | 1 year,8 days | (#44913267)

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.

Re:"Published on a Preprint Service"... (1)

ColdWetDog (752185) | 1 year,8 days | (#44913719)

Yes. Go look at some of the other titles. TFA is one of the more approachable ones . Your head will aslpode.

"Inflationary Instabilities of Einstein-Aether Cosmology "
"Simulation of homologous and cannibalistic CMEs produced by the emergence of a twisted flux rope into the Corona"
"ORIGAMI: Delineating Cosmic Structures with Phase-Space Folds"
"X-Shooter GTO: evidence for a population of extremely metal-poor, alpha-poor stars"

and of course, my favorite:

"The peculiar Raychaudhuri equation"

Depends on what powers the sun (0)

grantspassalan (2531078) | 1 year,8 days | (#44913279)

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.

Re:Depends on what powers the sun (3, Funny)

Mr. Slippery (47854) | 1 year,8 days | (#44913345)

...but if the hypothesis that the sun is externally powered by electric currents flowing in the spiral arms of the galaxy...

Is this some sort of inside joke? A reference to a Time Cube-style crackpot of whom I'm not aware?

Milk & Honey are good for you, but only if both are raw!

Oh dear. I suspect you're serious.

Re:Depends on what powers the sun (1)

ColdWetDog (752185) | 1 year,8 days | (#44913731)

Maybe an Electric Universe [electricuniverse.info] disciple.

Re:Depends on what powers the sun (1)

rasmusbr (2186518) | 1 year,8 days | (#44914435)

And your link contains a pretty convincing refutation of the whole idea of the Sun having a significant surplus of charge. If it were true the solar wind would consist of particles witch charge of one sign moving much faster than particles of the other sign.

"The solar wind is a flow of protons and electrons, away from the sun, in all directions, both at the same speed. Now, if the first "major property" of the electric sun model were true, we would expect the positively charged sun to repel positively charged protons, and attract negatively charged electrons. That's what the third "major property" says is happening, but we see that reality is somewhat different. The observation of electrons & protons both being "repelled" by the sun immediately negates any consideration of the sun having a net electric charge that can be detected anywhere in the solar wind flow. If the sun had a net charge that was large enough, then it should repel one charge and attract the other, depending on the sign of the sun's excess charge. But we don't see that."

Nemesis: Debunked theory (4, Interesting)

Misagon (1135) | 1 year,8 days | (#44913287)

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 [wikipedia.org] . I know of it only because I ready about it in a novel by Asimov [wikipedia.org] recently.

Re:Nemesis: Debunked theory (0)

Anonymous Coward | 1 year,8 days | (#44913671)

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

Isn't that the case for all stars, hypothetical or otherwise?

Re:Nemesis: Debunked theory (0)

Anonymous Coward | 1 year,8 days | (#44914271)

The guy who proposed the Nemesis theory postulates that our solar system is a binary system with the other star possibly a brown dwarf (if I remember right; regardless, something dim) on an elliptical orbit that takes ~22 million years.

arXiv (0)

Anonymous Coward | 1 year,8 days | (#44913331)

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.

What we need to know... (3, Insightful)

ebcdic (39948) | 1 year,8 days | (#44913377)

... is when we pass through the next one!

Re:What we need to know... (0)

Anonymous Coward | 1 year,8 days | (#44913609)

Yeah, because, good god, can you imagine what might happen to my real estate value when it hits?!

I better start saving up now...

Not exactly a new concept (4, Interesting)

Omega Hacker (6676) | 1 year,8 days | (#44913621)

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. ..."

Wasn't this already known? (0)

Anonymous Coward | 1 year,8 days | (#44913639)

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.

arXiv (0)

Anonymous Coward | 1 year,8 days | (#44913707)

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.

Summary wrong (again) (0)

Anonymous Coward | 1 year,8 days | (#44913815)

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."

Re:Summary wrong (again) (1)

czert (3156611) | 1 year,8 days | (#44914391)

(making an account on slashdot just to get my parent comment noticed.)

Bad Astronomy (1)

LuvWeasel (173561) | 1 year,8 days | (#44913817)

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. [discovermagazine.com] Given its age, I especially liked the punchline...

To be honest, I won’t be rushing to edit that chapter in my book just yet. This study looks good, but I’ll wait and see what other scientists say. With another few dozen million years to go, I have plenty of time.

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