Tuesday, April 12, 2016

Mass Extinctions Occur Every 62 Million Years

It has been an obvious question and it turns out that we are now able to refine it somewhat.  It is also reasonable that the probability of impact will increase sharply as we transit the center line.  Thus it appears that we are in a high risk era.

Saying all that, we are also approaching a level of technical ability that will allow us to create deep underground refugia for the entire population with the transfer capability to shift exposed populations away from any impact zone. I expect this to be done in concert with the complete terraforming of earth..

We have already posted extensively on the engineering of deep habitats.  One mile deep is easy as no temperature problems arise that cannot be easily handled.  Temperature engineering allows far deeper depths but that appears unnecessary.  The key is to pick stable geology and we have plenty of that.

Mass Extinctions Occur Every 62 Million Years

Thursday, March 24, 2016

Mass Extinctions Occur Every 62 Million Years


My colleague Judith Martin offered an intriguing article:

With surprising and mysterious regularity, life on Earth has flourished and vanished in cycles of mass extinction every 62 million years, say two University of California Berkeley scientists who discovered the pattern after a painstaking computer study of fossil records going back for more than 500 million years. Their findings are certain to generate a renewed burst of speculation among scientists who study the history and evolution of life. Each period of abundant life and each mass extinction has itself covered at least a few million years — and the trend of biodiversity has been rising steadily ever since the last mass extinction, when dinosaurs and millions of other life forms went extinct about 65 million years ago.

The Berkeley researchers are physicists, but they have analyzed the most exhaustive compendium of fossil records that exists of no fewer than 36,380 separate marine genera, including millions of species that once thrived in the world’s seas. Richard Muller and his graduate student, Robert Rohde, have published a report on their exhaustive study in the journal Nature.

“We’ve tried everything we can think of to find an explanation for these weird cycles of biodiversity and extinction,” Muller said, “and so far, we’ve failed.”

Suns position is two thirds out from center on arm of Milky Way

The evidence of strange extinction cycles that first drew Rohde’s attention emerged from an elaborate computer database he developed from the largest compendium of fossil data ever created.

1 - John Sepkoski Jr. suggested that marine life appeared to have its ups and downs in cycles every 26 million years. However, to Rohde and Muller, the longer cycle is strikingly more evident, although they have also seen the suggestion of even longer cycles that seem to recur every 140 million years. Sepkoski’s fossil record of marine life extends back for 540 million years to the time of the great “Cambrian Explosion,” when almost all the ancestral forms of multicellular life emerged, and Muller and Rohde built on it for their computer version.

2 - Muller has long been known as an unconventional and imaginative physicist on the Berkeley campus. Perhaps, there is an unknown “Planet X” somewhere far out beyond the solar system that’s disturbing the comets in the distant region called the Oort Cloud — where they exist by the millions — to the point that they shower the Earth and cause extinctions in regular cycles. Daniel Whitmire and John Matese of the University of Louisiana proposed that idea as a cause of major comet showers in 1985, but no one except UFO believers has ever discovered a sign of it.

Or perhaps there’s some kind of “natural timetable” deep inside the Earth that triggers cycles of massive volcanism, Rohde has thought. There is even a bit of evidence: A huge slab of volcanic basalt known as the Deccan Traps in India has been dated to 65 million years ago — just when the dinosaurs died, he noted. And the similar basaltic Siberian Traps were formed by volcanism about 250 million years ago, at the end of the Permian period, when the greatest of all mass extinctions drove more than 70 percent of all the world’s marine life to death, Rohde said.

Muller’s favorite explanation, he said informally, is that 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.

Periodic Mass Extinctions, Alexander's Thesis

Let us now look at Bob Alexander's thesis and calculations which I will vary somewhat to determine the actual length of the Cosmic Year. Periodic mass extinctions appear to have happened at least several times throughout the Earth’s history. The K/T boundary, as it is called, marks the end of the reign of the dinosaurs and is about 65 Million years old. It is popularly believed that a large asteroid struck the Earth causing a worldwide change in climate, which interrupted the food chain.

More recently discovered ‘Smoking Gun’ evidence points to another mass extinction, which occurred around 251 Million years ago when another large asteroid presumably struck the earth.

And there appears to be even newer evidence that mass extinctions may happen at the rate of every 62 Million years (+/- 3MY).
Period (End of) Die out rate / X

65 MYA (Cretaceous) 85 % /1 = 65 MY
208 MYA (Trassic) 25% over time /3 = 69.33 MY
245 MYA (Permian) 96% /4 = 61.25 MY
365 MYA (Devonian) 70% over time /6 = 60.83 MY
438 MYA (Ordovician) 50% + some over time /7 = 62.57 MY

Average 63.796 MY

By virtue of the chart above I believe the average is more like 63.796 MY, but for now let’s say that 62 MY (based on current physical evidence) is the periodic mass extinction average. 251 / 62 = 4.048 (Remember that number)

Something happens every 62 Million (or so) years, which puts us in harm’s way, so to speak. In its orbit around the center of the Milky Way Galaxy, our Solar system may also do this little sinusoidal motion from the top to the bottom to the top (and so on) of the Orion arm which we go around in. Now, what if the period of one cycle through the arm is around 124 Million years? Within one cycle, we would pass through the middle of the ring (the most dense part) twice and about every 62 million years.

As we spin around in the arm our forward motion (~150,000 miles/sec) is continuous, but if we go up and down also, that rate would change with position due to angular motion.

Now, it is bad enough that we would traverse this much more dense part of the ring, but we would go through its’ center at maximum velocity, much faster (in the up/down axis) than when we reach the outer edges of the arm where that relative motion (again up/down) stops altogether so that it can reverse. If we didn’t stop (in the up/down axis), we would just fly off into deep space and it would be bye-bye Milky Way. But luckily (or not) all of the mass nearer the center of the arm has gravitational force with acts to pull us back in for yet another cycle. It may well be that these huge killer asteroids do not ‘hit us’ as much as we run into them because of our high speed ‘sweeping’ through a large area of space.

The center of the ring isn’t a hard boundary, it is just more dense than on either side and there is a density gradient as you move away from the center. So, there is some latitude for interval timing due to this ‘kill zone’ principal.

The Earth has had eight centerline passes in 251 Million Years. The error of margin then is about 375,000 years per centerline pass or 187,500 years on either side of it. The dinosaurs were wiped out by a big asteroid 65 Million Years ago and we are due for the next one just about… yesterday… minus ~3 MY. In other words, either we are ~3 Million years overdue or just got lucky on this pass.
Let’s look at a few numbers.

The Milky Way Galaxy is about 100,000 Light Years (LY) in diameter. Our Solar system is about 26,000 light years or about 2/3 of the way out from the galactic center and we revolve at 250 kilometers or about 150,000 miles per second. We make one revolution every 226 Million Years, which means that we have made about 20 revolutions since the Earth was formed about 4.5 Billion Years ago. It is estimated that there are between 200 and 400 BILLION other stars in the Milky Way and that at least some of those have planets. It is likely from looking at our own Solar system that at least some of those planets probably have moons. That’s a lot of stuff – not to mention asteroids and comets.

a graphic, which illustrates the theory

It is believed that we are about 10 Light Years (LY) away from the centerline of the Orion arm, which is believed to be 3000 LY thick in our vicinity. We appear to be right in the middle of the rocks, the densest part of the arm.

If the last mass extinction was 65 Million Years ago and the half cycle period is around 62 MY then we are in a predictable (not to mention scary position) especially if we are moving away from the centerline.

If you think there is anything we could do to stop one of these killer asteroids if one were discovered tomorrow, you have been watching too many Hollywood movies. However, NASA places a high priority on finding Near- Earth Objects (NEOs) and protecting Earth from them.

Established in 1998, NASA’s NEO Observations Program is responsible for the Agency’s efforts at finding, tracking, and characterizing NEOs. The agency’s Jet Propulsion Laboratory, in Pasadena Calif., conducts the daily operations of the program. In 2010, NASA fulfilled a congressional mandate to discover at least 90 percent of 1-kilometer-sized NEOs, and is now working hard to find smaller NEOs. NASA’s NEO Observation Program is also a key member of the International Asteroid Warning Network (IAWN), organized last year by the United Nations. In response to UN COPUOS recommendations, space agencies are also establishing a Space Missions Planning Advisory Group to consider options for planetary defense against potential NEO impacts with Earth.

This artist’s concept (above) shows the Wide-field Infrared Survey Explorer, or WISE spacecraft, in its orbit around Earth. In 2013, the mission was brought out of hibernation to hunt for more asteroids and comets in a project called Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). The Asteroid Initiative, which includes a bold mission to identify, capture and relocate an asteroid through the Asteroid Redirect Mission, and the Asteroid Grand Challenge to find all asteroids threats to human population and know what to do about them. Thanks to Nature and NASA - Judith Martin

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