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View Full Version : Mass Extinction Every 63 million years



lswinford
2005-Mar-11, 10:16 PM
David Pearlman, San Francisco Chronicle Science Editor, reports Mass extinction comes every 62 million years, UC physicsts discover (http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2005/03/10/MNGFIBN6PO1.DTL&type=printable) on Richard Muller and Robert Rohde's report in Nature of the pattern of reoccurring extinctions. Also of Berkeley, James Kirchner observes the idea "simply jumps out of the data" from Muller and Rohde's study.

Muller was known for publicizing his musings of a distant but captive dwarf star he called "Nemesis" that may have caused an asteroid to veer our way and caused a dinosaur extinction. There's the idea of a "planet X" that periodically sweeps by the Oort Cloud or "the solar system passes through an exceptionally massive arm of our own spiral Milky Way galaxy every 62 million years, and that that increase in galactic gravity might set off a hugely destructive comet shower that would drive cycles of mass extinction on Earth," as Pearlman reports Muller. Rohde, it seems, appears to prefer some geologic cycle affecting plate techtonics.

Any thoughts?

scorpio711
2005-Mar-11, 10:50 PM
Interesting... I had read quite some time ago (I don't remember the source unfortunately :( !) that there was a periodicity of 26M years and we are now right in the middle of a cycle (means the last period was 13M years ago). The serie was quite impressive, I've kept the data, here it is:
- 65M (-13 - 2*26): end of secondary era, dinosaurs extinction, K/T transition
- 213M (~ -13 - 8*26): end Jurassic, massive extinction
- 248M (-13 -9*26): beginning of secondary/trias, massive extinction
- 360M (~-13 -14*26): end of carbonifer, massive extinction
- 438M (~-13 -16*26): end of silurian,massive extinction
- 590M (~-13 -22*26): begin. of primary era,massive extinction

In addition, transitions between periods with no massive extinction but minor ones & big changes anyway also show same distribution:
- 520M (~-13-19*26): begin. of ordovician
- 408M (~-13-15*26): begin. of devonian
- 286M (~-13-10*26): begin. of permian
- 144M (~-13-5*26): begin. of cretaceus

The assumption in the article was a disturbance (unknown cause/some resonance effect?) in the Oort cloud every 26M years that caused massive fall of numerous objects like comets onto the inner solar system, with bombing of planets including earth and occurrence of catastrophes.
If we do a linear regression of all the "points" of the curve, we find a correlation of 99.9% which is quite impressive !

Scorpio

astromark
2005-Mar-12, 01:49 AM
:o Oh boy. So we need to make planes to iether protect our selves or move into a quieter naughberhood. therteen or so million years is a very long time and unless we get a roage hit we have little to worry us for a while a... B) BUT
Is the Earth entering a life exinctioning ice age. As we are all aware of the ever changing and extreem weather paterns which bombard us with ever increasing regularity. Or is it that we have changed the planets balance to our detriment. I have noted that the 100 year floods are with us every 10 years. Is this global warming that is wrecking havock on us. Or is it just the nateral processes of this planet. Is our atmosphear thinning? Is there a carbon build up ? Are the oceans rissing ? Ozone depletion, our fult or nateral events ? Ice age, Heat wave, ? which is it to be ? None of the above. We are going to get smacked by a larg rock or comet. Damb. Its going to hit the planet with such force that it will punture the crust sending millions of tons of debri and lava into the atmosphear darkening the skies for hundreds of years. all sounds a bit grim really. I think I now understand religion. :unsure: Now dont get upset with me, i am just demonstrating that we could spend a lot of time in panic mode regarding the fate of our little blue dot, and the life that dwelse on it. The truth is more complicated than I can convay.
We thrive, florish, and servive only until. . . until. :blink:, we dont.

isferno
2005-Mar-12, 01:50 AM
Great, so its at aphelion right now. How would you look for something that's probably hanging still in the sky.

A different possibility might be Earth's magnetic field.

Earth Magnetic Field Reversal (http://www.pureenergysystems.com/news/2005/02/27/6900064_Magnet_Pole_Shift/)

Of coarse, this might be more suggestive then reality, though, being hit every time by a meteor just as nemisis passes by seems quite unlikely to me.

While with radiation, you might expect animals to survive which have some adoption in the way they protect their virtilized eggs. Buried eggs, underground holes, underwater, etc.

GOURDHEAD
2005-Mar-12, 04:07 AM
Here (http://www.universetoday.com/forum/index.php?showtopic=2745&hl=galactic+disk) is a discussion of the solar system's path through the galaxy including the oscillation through the disk with a period of 66 million years travelling 56 parsecs from peak to trough. Although I'm amazed that we can have measured this with reasonable accuracy, if true, this may be the source of the periodicity of the extinctions. I seem to remember that the MW's disk is about 10 thousand light years thick. If so, we must be confined near the galactic north/south (latitudinal) center of the disk where there may be all sorts of flotsam and jetsam previously expelled from stellar systems.

antoniseb
2005-Mar-12, 08:43 AM
Originally posted by GOURDHEAD@Mar 12 2005, 04:07 AM
I'm amazed that we can have measured this with reasonable accuracy
I don't think this is measured. We have looked at the velocities of our Sun and other stars in relation to the plane of the Galaxy, and made some calculations about the effect of the gravity of the presumed density of the matter in the disk. This presumption was based on the orbital velocities ofthe stars in the disk.

I did this calculation in Freshman physics back in college. It was an application of working out gravitational influence for different geometries of mass. In this case, we looked at the distribution of matter in a plane, as opposed to a central sphere, which is the usual configuration.

GOURDHEAD
2005-Mar-12, 02:18 PM
While with radiation, you might expect animals to survive which have some adoption in the way they protect their virtilized eggs. Buried eggs, underground holes, underwater, etc. Whatever the cause of mass extinctions, there are questions begging to be asked.

How could whatever caused the permian extinctions have allowed what became the dinosaurs, their avian and marine cousins, turtles, amphibians, and crocodilians to survive? What happened at the begining of the permian (to probably weaken the microbial immune systems) to cause the proliferation of the multicellulars? How could turtles, birds, crocodilians, and the even less likely smallish less passive mammalians have survived the K-T boundary extinctions. Birds and mammals are even more enigmatic because of their small size and more active metabolisms, a steady diet is more essential than for the others that could assume a form of dormancy for considerable periods of time. Could they have fed off the carcases of the larger animals for such a long time? The great variations in the extinctions of marine phyla is also a puzzle. My guess is that those that went extinct were aided and abetted by the proliferation of diseases which were initiated by the primary event.

Note that life, once started, is difficult to stop. which is not necessarily true for the case of a given species.

Plat
2005-Mar-12, 06:10 PM
Originally posted by GOURDHEAD@Mar 12 2005, 09:18 AM
Note that life, once started, is difficult to stop. which is not necessarily true for the case of a given species.
I cannot agree more, once life pops up you cant get rid of it...or it will be very hard to

lswinford
2005-Mar-17, 08:45 PM
Well it is pretty hard to sterilize our space probes, so we don't innoculate other worlds. I remember, more than a few years ago, reading Andromeda Strain and how M C described the clean-up necessary for the people needed to study an alien microbe.

Oh, and one of the lines of evolutionary thought is that we make leaps. That was a cute justifying piece that they used on the original X-men movie a couple of years ago, though the original idea had been honestly kicked around for a while before fiction picked it up.

twig6161
2005-Mar-24, 05:58 AM
...actually there was a massive asteroid that struck the eath in the south pole regon that should of,if it didn't hit a very largr ice field,during one of our ice ages that surely would of been a catatrophic event...happened approx 750,000 year ago...it not a well documently hit ,being recntly discovered,within the last few years,but I believe Gwynne Dyer wrote about it not that long ago,so maybe you all should not worry so much...believe me!...check it out I'm sure I'm not error of myself

Bob Henstra
2005-Mar-24, 08:07 PM
Again, nothing more then speculation. "Scientists" making a living, publishing material impossible to collaberate, Its simple, just make the aspects of the idea real old, it happened waaaay back there, will happen again so many millions of years in the future, accepted today as the newest truth and then promptly forgotten the second the newest "posit" is published. A familiar circle! (song) "When will they ever learn?" :D

John L
2005-Mar-24, 08:48 PM
Gourdhead,

The K-T extinction is marked by iridium, an element rare on Earth but common in sapce, and tectites, small glass droplets formed by melted rocks raining back down to earth. There are only two know events that could cause both of these. One is that the irridium came from an impacting asteroid that was vaporized on impact, along with a large mass of the Earth's crust at the impact site, and that these materials rained down on the surface with the detrimental effects we've all heard before. The other is the detonation of a nuclear bomb at or near the surface, where the irridium was a by-product of the fission reaction in the explosion, and the tectites were melted and thrown into the atmosphere by the force of the explosion. In my opinion, the K-T extinction was caused by a nuclear war among the dinosaurs.

Bob Henstra
2005-Mar-24, 10:55 PM
Dino's in a nuc war!!!
(LOL) liked that one!,

The poet muses;

Doth speculation satisfy notion without reality
dost dream of things beyond the moon and dost thou hope to dwell there soon?

long ago a common man explained how we must learn and I quote

"by line upon line and precept upon precept"

Real science is about discovery of truth which happens a little bit at a time, and is added upon truths already discovered, and it happens in the now, not 65 million years in the past or the 65 million years into the future.

I simply choose to learn by discovery, mine and others, not by outlandish speculation.

John L
2005-Mar-24, 11:48 PM
What of our civilization will remain in 65,000,000 years? What remains of human civilizations from 1000, 2000, or 10,000 years ago? In 65,000,000 years scientists will find layers of irridium and tectites at scattered sites around the world. They may no longer be named Nevada, New Mexico, Australia, or Russia, but those deposits will still be there. Will those future scientists attribute too our layers of these materials to an asteroid impact? We still have only small amounts of representative fossiles from the end of the age of dinosaurs, and humans have gone from simple monkeys to the dominant species on the planet in only 1,000,000 years. And our true mark on this world has only come in the last few thousand as we've learned to alter the land and world to fit our needs. Once again I ask, what of that will still remain in 65,000,000 years that could be recognized as the work of inteligence?

pratnayake
2005-Mar-25, 12:07 AM
[COLOR=green][SIZE=1][FONT=Courier]

I have read a similar story many years ago. In that article the writer (I cant recall his / her name- or the publication :angry: )suggested that our sun may have a sister or a brother (a twin sun system) and when they come closer each other, astronomical disasters such as mass extinctions can happen. :o

isferno
2005-Mar-25, 12:25 AM
I notice this thread is still active :)

Check out this page, including the reference to the pdf file at the top of that page
Nemesis (http://www-muller.lbl.gov/pages/lbl-nem.htm)



And for those who like pictures of a might be nemesis.
here is a fun found picture. the right hand side is the original (clipped) image, as found on UT.

http://home.tiscali.nl/sfictie/nemesis.gif

Bob Henstra
2005-Mar-25, 01:23 AM
70 million years, now thats a long time for dinosaur DNA to survive isn't it? No chance, 70 million years, wow! Not possible!

http://newsmax.com/archives/articles/2005/...24/155959.shtml (http://newsmax.com/archives/articles/2005/3/24/155959.shtml)

Dinosaurs died 4449 years ago in a very muddy flood. A flood whose sediments, layed down layer upon layer, are now dated by "scientists" at millions and even billions of years old.

The thing about it is written history, we have written history of this flood in many languages. All we have for sure about the scientific point of view is the earth was clobbered several times by something big, and the fact that dinosaurs died. That one was the result of the other is, again, pure speculation.

70 million years, a long time for dinosaur DNA to remain viable. 4449 years is more like it!

isferno
2005-Mar-25, 09:20 AM
The actual statement in the story is:



It was recovered dinosaur DNA - the blueprint for life - that was featured in the fictional recreation of the ancient animals in the book and film "Jurassic Park.


What they found is equivalent to a biological rubberband, which may only contain the protein buildingblocks. This would be the same as telling what the rubber is made from (ex. which tree).
I doubt they will actually find DNA. This would only be possible under special (natural) preserving circumstances.

John L
2005-Mar-25, 02:28 PM
That's the Nemesis theory that ISWINFORD mentioned in the second paragraph of his post. This guy has been pushing this idea for some time, and its not impossible, but with all of the telescopes now in operation with IR sensing capabilities you'd think they'd have noticed a brown dwarf by now.