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Galactic Origin For 62M-Year Extinction Cycle?
Hugh Pickens writes "Cosmologist Adrian Mellott has an article in Seed Magazine discussing his search for the mechanism behind the mass extinctions in earth's history that seem to occur with a period of about 62 million years. Scientists have identified nearly 20 mass extinctions throughout the fossil record, including the end-Permian event about 250 million years ago that killed off about 95 percent of life on Earth. Mellott notes that as our solar system orbits the Milky Way's center, it oscillates through the galactic plane with a period of around 65 million years. 'The space between galaxies is not empty. It's actually full of rarefied hot gas,' says Mellott. 'As our galaxy falls into the Local Supercluster, it should disturb this gas and create a shock wave, like the bow shock of a jet plane,' generating cascades of high-energy subatomic particles and radiation called 'cosmic rays.' These effects could cause enhanced cloud formation and depletion of the ozone layer, killing off many small organisms at the base of the food chain and potentially leading to a population crash. So where is the earth now in the 62-million year extinction cycle? '[W]e are on the downside of biodiversity, a few million years from hitting bottom,' writes Mellott."
yesterday there was the same story, except it was 150 million years.
I read about it in books which must have been published 30 years ago, though I think the theory than was than the gravitational field of passing stars was changing the orbit of comets in the Oort cloud and causing comet impacts.
http://michaelsmith.id.au
BBC documentary series Horizon, c.late 1980s
My web domain.
Mabye cosmic rays effect the ozone layer, I don't really know. However claiming that CR's increase cloud cover is stretching the science well beyond what is known.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Imagine the earth floating on a sine wave. The sine wave passes though the zero point. The zero point is a plane which contains the hot gasses. Are going to be other civilisations outside this cycle? Are there other civilisations who thrive inside the plane? Do some humans need to grow a brain?
Does it go on forever?
from TFA: It turns out that the biodiversity minima of the 62-million- year cycle happens when the Sun is âoebobbed upâ on only one side of the galaxy, when the solar system is on the diskâ(TM)s upper, âoenorthâ side...These [cosmic rays] should be showering the north side of the galaxyâ(TM)s disk. We are protected by the galactic magnetic field, much as the Earthâ(TM)s magnetic field protects our planet. When we rise to the north side, we are less protected.
I made that observation for myself a long time ago. Large meteor impacts tends to have 32M years interval.
Every 62 million years, a giant goatse monster appears and sucks 95% of life on this planet into it's anus.
Better find something strong to hold on to!
Its also possible that my opening of a coke can will unsettle the quantum state of the water molecules vaporized in the air consequentially causing a pony to spontaneously appear. But as much as i wish it to be true, it aint going to happen (at least not for a really long time).
The whole point of the 65 million year cycle was not only the extinctions, but also the discover of elements in the ground only found as a result of asteroid impacts. Tha'ts why researches spend to much time trying to find a large mass that could disturb the Kuiper belt.
What an incoherent rant. Perhaps you should lay off the vino before posting to slashdot.
It's Candlejac@:P:{}n o c a r r i e r
The interval between extinctions is 62 million years only if you accept ~30 millions of year of error margin.
The current downfall of biodiversity is really fast compared to the time scale mentioned here. Its most likely reason has two legs, two arms, a big brain and a various set of forest-destroying machines as well as a bad habit of dumping various materials into the ocean.
The Wise adapts himself to the world. The Fool adapts the world to himself. Therefore, all progress depends on the Fool.
Us passing some gas clouds every 62 million years can't explain those extinctions.
I am passing gas way much more frequently than that without any major damage.
you're so f**king right man. this article is f**cking stupid. i get you cause i drank a barrel of wine earlier too. OBVIOUSLY, the gas cloud is orbiting the milky way at 62 million year intervals and we're the ones standing still. IDNTRTFAWIDTBYDE (i don't need to read the f**king article when i'm drunk too because you didn't either)
As others have noticed, this is hardly new. I'm starting to think we just have too much knowledge these days. I've lost count of the number of 'discoveries' that are already known, both in IT and the wider areas of science and beyond. It's effectively impossible for people to fully grasp the entire sum of knowledge in their field with the result we're starting to spend time 'reinventing the wheel' to a depressing level.
I want a list of atrocities done in your name - Recoil
Its actually the Infinite Improbability Drive in action. Research my ass. Before you ask any more questions, 42.
Real men read Slashdot articles at -1, bottom up.
This is about the motion of our star relative to the disk. Because our orbital inclination around the galactic core is different from other stars in the galaxy we tend to drift above the disc, then we get pulled back by gravity and pop out the bottom of the disc. When we pass through the disc we encounter more objects such as stars and gas clouds.
http://michaelsmith.id.au
Those gas clouds are probably circulating at the same speed as us.
Nice assumption. TFA apparently assumes otherwise. Now I don't know which one of you is right, but at least they did not call people names without even bothering to read their text and without bothering to give any more of an explanation for their opinion other than "I mean, for Christ sakes [sic!]". Which leaves only one fucking twit here, as I see it.
Rudolf Hess edited Mein Kampf. He was the very first grammar nazi.
theory about 20 years ago. However that one suggested the reason for the mass extinctions was because the stars in the galactic plane are much closer together so the likely hood of being in close proximity to a supernova and all the incumbent radiation that entails is much higher. This also explains why occasionally mass extinction skips a beat. Of course the 2 scientists who postulated this theory were promptly laughed at and ridiculed by the scientific community in that very grown up way that scientists do.
Cold fusion anyone?
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
All this has happened before and will happen again.
Take a look at wikipedia's graph of extinctions from the article about the history of life. I haven't done any actual signal analysis on this data.
I would buy that there is a bit more energy in the per 62 million years signal, but I wouldn't call it clockwork-like regularity. If they came up with a p-value of 0.01, I'd say that there must be something happening, but I would expect a little more consistency out of a big cosmic event like the one they're describing.
[W]e are on the downside of biodiversity, a few million years from hitting bottom,' writes Mellott
I totally agree with that assumption, though I personally think Adrian Mellott should have left out "the few million" part.
Well we're all gonna die on December, 21 2012 anyway, so why bother???
had a story that's strangely similar: "The Poison Belt". Except that instead of radiation, it's poisonous aether.
Tor the "skeptics" are desparate for anything, anything at all which can be called "science" that can somehow justify continuing to mine and burn coal and avoid investing in environmentally responsible energy policy
Shut down the mass relays!
M94 is about the age of the universe: 13-18Bn years old.
It is out of the plane of the milky way.
Yet it still remains a cluster, not shocked apart by its life in the danger zone.
I would say encountering a star would definitely fit the description of "hitting the bottom of bioversity"
This is about the motion of our star relative to the disk.
OCIADBTRTFA (Of course I also didn't bother to read the f**king article), but what the hell has the Discworld to do with this???
What if the Great A'tuin would change course? Huh? We wouldn't even know, because we're not ON the f**king Discworld. It's fiction.
[/deliberately off-topic]
can't wait to see it in action the next michael bay movie
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
The real question is; and so what if we're gone?
After reading some of the contributions on /. I completely agree.
An SQL query goes to a bar, walks up to a table and asks, "Mind if I join you?"
Ha! With good ol' human ingenuity, I'm sure we can hit bottom a lot faster than that!
http://alternatives.rzero.com/
yes, here everyone worries about black holes taking everything, but actually it's those red holes that are dangerous.
The Galactic disk.
On a related topic I recently rented a movie of The Color of Magic. The elephants were shown standing motionless on the turtle with their heads pointing out and their tails pointing in. I had always assumed that the elephants were lined up around the turtle head to tail so to speak so that they could rotate the disk while the turtle kept pointing the same way.
http://michaelsmith.id.au
Chime in here with any information on this.
I was lead to believe at one point that the Mayan Calendar's "Beginning of time/End of time", December 21 2012, corresponded to when our Solar System transverses the plane of the Milkway.
Where these people a few million years off? (Amongst other things)
Not to be anal, but his name is spelled Adrian Melott , with one L. This spelling will help if you google his name.
I attend the University of Kansas (where he teaches), and know this guy is associated with some pretty far out ideas.
Actually the true danger is in white holes. You never know what will come out of them.
The Tao of math: The numbers you can count are not the real numbers.
but why would they rotate the disk if the sun is rotating around the disk?
Showing my unfamiliarity with discworld physics here. I assumed that the sun around turtle+elephants+disc is one year, while one turn of the disc is one day.
http://michaelsmith.id.au
Seriously, that would cause mass extinction [http://en.wikipedia.org/wiki/Gamma-ray_burst]. Though the odds aren't great of one happening. However, if one considers that galaxies move and collide all the time, then I suppose over the course of Earth's history it's possible that the Earth came really close to a Super Nova at the same time a Gamma Ray burst happened.
The odds aren't good.
FYI we get bombarded by Cosmic Rays all the time.
This guy needs to publish a paper and not "speculate" in a magazine. Pseudo Science, nothing to see here, move along.
So sue me.
It's still an old globular cluster.
Remember how many people on the planet think that just *believing* something is ok ("I believe in a god", "I blieve there is no global warming" etc etc) - it will take 5 million years to get everybody to accept this and start working on a solution!
If Google really cared they would fix Android Chrome to reflow text, instead of discriminating
Maybe it wasn't radiation that killed off all those critters. Maybe the stars were just right.
no time ;-(
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Well there will be the damn dirty apes!
But they won't give a damn either about us.
"I am the king of the Romans, and am superior to rules of grammar!"
-Sigismund, Holy Roman Emperor (1368-1437)
Sure, but where's the silver surfer come to warn of Galactus? Maybe Jack Chick was right all along
FreeBSD for the impatient.
Nightfall (Isaac Asimov, 1941, and Isaac Asimov & Robert Silverberg, 1990)
Tsunami -- You can't bring a good wave down!
>> IDNTRTFAWIDTBYDE (i don't need to read the f**king article when i'm drunk too because you didn't either)
I finally realized that, today, for the first time I've been on Slashdot too long.
I was able to understand your acronym without the explanation just by looking at the letters.
OMG.
There's a gorilla from Manilla whose a fella that stinks of vanilla and has salmonella.
The sun at this point is well over halfway through its yellow-phase lifetime. Earth only has a few billion more years left to reach whatever culmination it's going to. There's not really enough time to evolve another species to our level from scratch. A mere 95% extinction wouldn't be as bad, but if it's only 60-some-odd million years from now the next sentient species is going to have to make due with dramatically fewer energy reserves left on the planet to bootstrap its civilization.
In short, if you value sentience we're a pretty valuable resource for the solar system.
E pluribus unum
...to build the shield generators that will protect our ancestors from the rarified hot gases.
Guess that means no Duke Nukem Forever this time around. Hopefully they'll time-capsule the source, at least.
So when the stars are right, the living creatures of Earth all die. Sounds like it's nearly time for Cthulhu to rise again!
Interesting idea. But what about the Iridium anomaly then?
The very basics of "Cap'n Trade"
Rich people "Trade" us money for extended life. We pop a "Cap" in the poor people...
Same as our society has always run...
Cap'n Obvious
But do we eat the pudding now or not?
This hypothesis is old and was used as part of the story "Calculating God" written by Robert J. Sawyer in 2000. It's an excellent book which I can heartily recommend. You might also be familiar with his work through the "Hominids" alternate earth trilogy.
Know that this paper has come out we need to increase the chances for all life to survive. By increasing C02 levels, we will trap more radiant energy which will negate the increase cloud cover. The additional CO2 and smog will create a "shield" against the cosmic rays! Come on everyone buy any American SUV and start driving! We will stimulate our economy and save the Planet!
Usupported by actual data. If you look at the Phanerozoic biodiversity data, it doesnt validate the 62 million years extinction cycle theory. You cant just take a small subset, selectively ignore data points that don't fit into your theory and preach the end of the world. Admittedly that does seem to sell books.
I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered. My life is my own.
when we finally figure it all out, it will completely change...and some maintain it already has...
There's not really enough time to evolve another species to our level from scratch.
Well, perhaps not from scratch, but even the most massive of mass extinctions wouldn't destroy all life. There'd be plenty of bacteria, amoebas, and various other "simple" organisms around. Given that the majority of evolutionary time was spent developing these basic organisms, life would start out with a rather large head start as compared with starting from nothing.
A mere 95% extinction wouldn't be as bad, but if it's only 60-some-odd million years from now the next sentient species is going to have to make due with dramatically fewer energy reserves left on the planet to bootstrap its civilization.
Well, not necessarily. Fossil fuels aren't completely nonrenewable - they're just nonrenewable on any sort of human timescale. 60 million years is about the age of the coal and oil we're burning now. If there was a 95% extinction today, then the next sentient species would start out at with about the same amount of fossil fuel reserves that we had.
We all know what to do, but we don't know how to get re-elected once we have done it
What?! I'm outraged!
Humans are responsible for all bad things! Humans are not part of nature! That's what the media tells me. How dare something else be responsible! How dare our actions not be as important as we think they are!
I find being offended by me offensive.
The Five Big Extinctions were at 65, 206, 251, 364 and 439 million years ago.
I don't see much of a 62-million year cycle in those extinctions.
Hrm, I'm only glancing over the article in question, but I was just last week at a conference (North American Paleontological Conference, held in Cincinnati) where this work was presented.
As others have pointed out, cycles of diversity in the fossil record have been pointed out before, as have cycles in extinction rates. Dave Raup and Jack Sepkoski did some very important work in this. However, paleontologists have gone back and forth on whether that cyclicity really exists or not.
Melott and Bambach (Richard Bambach... a very very important paleoecologist!) presented work at NAPC that they have found the 62 mya cycle in a number of very different datasets of fossil diversity. This is important... it means the signal is very likely to be real.
I can't speak as to the astronomical mechanism they postulate; in the talk at NAPC, they suggested it might have to do with continental erosion rates (which is related to an idea Bambach has pushed many times before, particularly in a paper entitled "Seafood through Time" in the journal Paleobiology).
It will be more interesting, as Mike Foote (UChicago) pointed out at NAPC, to see if this cyclicity exists in the seperate origination and extinction rates, the combination of which produce the changes in diversity. Melott and Bambach were not at NAPC however, and the person they asked to substitute for them to present their paper (Eugenie Scott, head of an important science education taskforce) could not speak on the details of their work.
Spiral Arms Did Not Cause Climate Change on Earth
A new map of the Milky Way galaxy proves that the sun's motion through the spiral arms could not have caused a well-known climate-change cycle.
http://www.technologyreview.com/blog/arxiv/23763/
And that was the one time Albert was wrong...
Well, I'm glad that if Mellott is actually correct, I'll be long dead before this actually occurs, kind of like my fervent hopes for the destruction of Earth at the hands of a gigantic meteor. Although, this poses a question. Would you LIKE to be around to see Armageddon, or not? I'm pretty sure you can classify this scenario as Armageddon if it essentially wipes out a huge amount of life on Earth.
amoebas will survive? awesome.
..the Earth leaving the Sun's heliosphere? As described in this article a few days ago: http://www.newscientist.com/article/mg20227144.700-sun-leaves-earth-wide-open-to-cosmic-rays.html The (predicted) length of time for a cycle for this event, and the event described in the story is only a single order of magnitude off. Fairly common yet acceptable difference in in the field of Astronomy, I've been told.
Probably pretty close to the same speed, yes.
But, alas, not necessarily close to the same velocity.
To use a car analogy, two cars going 75 mph are both going the same speed. If one is eastbound on West Esplanade, and the other northbound on Power, they'll have a velocity differential of over 100 mph when they meet at the intersection of Power and Esplanade...
"I do not agree with what you say, but I will defend to the death your right to say it"
... and a dollar short.
This is twice in a week that someone has made assertions about mass extinctions, and both times their (different) numbers don't match the commonly accepted numbers http://en.wikipedia.org/wiki/Milky_way . (No, the Big W is not necessarily authoritative, but the sources referenced are.)
The solar system orbits the galactic center in 220 Myr. It oscillates through the galactic plane 2.7 times per orbit. That's a period of 81.5 Myr, and each crossing at half-period being 40.75 Myr. I doubt anyone would consider that an acceptable error margin.
Furthermore, the matter density in the galactic plane oscillates with a period 1/2 that of the galactic rotation, expanding out from the center in waves (density wave 25 Myr; spiral structure 50 Myr). Passing through the plane would have little effect unless these two coincide.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
We already know why one extinction event happened. The current one is caused by us. These leads me to believe that there may be some variety in causes of mass extinctions, and that no single theory will cut it.
Play Command HQ online
Oil and coal formed as there were not enough species of bacteria to cause decay before they got fossilized Arguably this will not happen anymore as most organic (and even some non organic) have bacteria which will cause them to decay in very short period of time into CO2, methane etc etc...
Only one question matters: when is the next one due?
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
From universe today:
Past Climate Change Cannot Be Tied to Earth Passing Through Galactic Plane
http://www.universetoday.com/2009/06/26/past-climate-change-cannot-be-tied-to-earth-passing-through-galactic-plane/
will heed the galactic call to "Aboort! Aboort!"
Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
Modding him up +1 FUNNY, was the other option. I quite enjoyed it. :)
From TFA:
(Huh? Gravity pull is an acceleration, not a velocity.)
I don't follow this. If the supercluster is pulling us in, it's also pulling in the intergalactic gas. We should be flowing along with that gas, not blasting through it.
How will the "We Have To Get Off This Rock wackjobs react to this? a) they will realize they are utterly out to lunch and give up, or b) they will now stridently insist that not only must humanity magically leave earth, but leave the galaxy as well!
You know which one they'll choose...
"Melancholy Elephants". http://www.spiderrobinson.com/melancholyelephants.html
You are not a brain: http://books.google.com/books?id=2oV61CeDx-YC
The galactic plane is nonsense. It is 1 to 62 million light years away. If it was all so encompassing won't we see a insanely super wall of hotter than the sun nebula the edge of the universe per say just how they thought the world was flat that you fall off at the edge of it. Also what is the warp factor of the earth travel at? to the edge of the universe.
Also if the earth had already passed through it and there has been 20th extinction why is earth the only planet in our solar system that has life on it? While the other planet doesn't see to be affected by its transverse through this plane.
Humans will survive, too. Unlike dinosaurs, we know about things like 'lead plate stopping radiation'. If you're lucky, you amoebas will be inside the lead-plated bunkers with us. As our food source! Muahahahahaha*gasp*hahaha*cough*.
Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
And in particular, they will wave back.
OMG....! It's only Schrodinger's pony!
(and in one helluva damn big box!)
.
- aqk
F U
space ship snug and safe from the interstellar soup dust.
Ohai, do you have a PhD in Physics and decades of experience in research?
BAWITDABADABANG...
-Kid Rock
(damn caps filter)
simple, fast homepage with your links: http://www.ngumbi.com/
You're assuming we're not going to be in the surviving 5%. Considering a substantial ability to terraform and a relief from ethical concerns regarding GM food stocks (plants and animals) we've got a survivability as a species just under that of the cockroach.
The land shall stone them with the bread of his son.
The inter-galactic gas of the Local Group will hit the inter-galactic gas of the supercluster (Virgo) resulting in shock waves which will be transmitted to gas within the component galaxies, with possibly significant effects within those galaxies.
Clearer now?
Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"