Posted on 10/27/2009 8:12:33 AM PDT by mudblood
Science is NEVER settled!!! A constant reevaluation and “but what about ...?” analysis is a very good and healthy thing.
OK, I’m calling BS on this one, just because of all the crazy rip off schemes in the adds with the article. Nice try.
He’s not being funded by anyone for his research. Its hard to research and work at Wendy’s at the same time. I can’t believe I’m defending making money on the FR.
There are advertisers, and then their are people who sell gold as an investment.
So why does Mars have no magnetic field to speak of??? If its simply a matter of being a planet spinning in space, its electromagnetic field should have collapsed in the pockets that it has today.
I’m not saying the theory is wrong, just asking, how it handles this counter example.
I can understand how a rotating iron core can cause a magnetic field. What I can’t understand is how this theory explains the periodic reversal of this magnetic field.
Hey, what the heck, Einstein worked at a patent office to pay the rent. Of course, not everyone who works at a patent office is Einstein...
I looked into that a little, using googly on the internet. Mars is stated as having a magnetic field, but weaker than Earth. But it is a smaller planet, in a different orbit, etc. Also, this isn’t my theory, it has to stand on its own two feet, I’m totally cool with that :)
“Basically the huge eddy currents created as the core interacts with the mantle.”
The problem with that is that generating these eddy currents would slow the rotation of the earth. Ar the same time, the same magnetic coupling would increase the speed of the core to that of the mantel.
Over hundreds of millions of years it seems that that isn’t happening.
Iirc, the moon has a bit to do with this.
It has actually a scattered field as I understand it, with stronger pieces and weaker pieces, but not a uniform field aroudn the planet, according to the surveyor, its not constant at all.
The prevailing theory as I understand it is that Mars used to have one, possibly because of a large moon that the planet captured which spun the planet at a much higher velocity that it does today, because mars alone while comparable in size, is not comparable in mass with the Earth.
The theory further purports that this massive satellite eventually crashed into mars, most likely in the northern hemisphere creating the distict differences northern and southern hemispheres of mars.
Also without this satellite to keep it spinning fast, the dynamo collapsed, and with it the marsian atmosphere that the dynamo created and protected.
Again, I am not saying this current theory is wrong, just that mars seems to stand in stark contrast to it.
I think you may be onto something, and his theory has to account for it to work.
Xcamel,
The article you linked to, while very interesting, is not a refutation of the theory in question that mudblood has posted. Instead, it is merely a description of an inconclusive experiment.
Ordinary iron and carbon-steel loose their property of being attracted to a permanent magnet at roughly 800degC.(much cooler than the earth’s core) I know this from experience. Of course not all magnetism ceases at that temp, but any magnetism left is very weakened and must exist only at the atomic level.
It may well be that the theory, that is the subject of this thread, is bogus. But I would not find it surprising, if it were found in the future, that the generation of earth’s magnetic field proved to be more complex than can be explained simply by the rotation and/or circulation of our molten iron core.
I would also like to know the credentials of the person who is proposing this new theory.
A friend recently loaned me a video made by NOVA that goes into this subject. It is called “Magnetic Storm, Earth’s Magnetic Shield” folks who are interested in this subject might enjoy that video if they can find it.
This bares out in the fluctuations of the magnetic field at the surface, which match up with density fluctuations measured in the core.
The article I posted seeks to replicate that effect, and inasmuch, has done so.
The 1995 Glatzmaier model unexpectedly reversed polarity and obviously must do a pretty good job of explaining the situation:
I'm puzzled about this quote you took out of context, namely:
From National Geographic:
“We can see reversals in the rocks, but they don’t tell us how it happens,” said Gary Glatzmaier, an earth scientist and magnetic field expert at the University of California, Santa Cruz.
In point of fact, your quote was part of the following article about how the Glatzmaier model in fact explains the flip, the exact opposite of what you tried to use the quote for. Here's the full article from which you excerpted your quote:
Why Does Earth's Magnetic Field Flip?
John Roach
for National Geographic News
September 27, 2004
Earth's magnetic field has flipped many times over the last billion years, according to the geologic record. But only in the past decade have scientists developed and evolved a computer model to demonstrate how these reversals occur.
"We can see reversals in the rocks, but they don't tell us how it happens," said Gary Glatzmaier, an earth scientist and magnetic field expert at the University of California, Santa Cruz.
Based on a set of physics equations that describe what scientists believe are the forces that create and maintain the magnetic field, Glatzmaier and colleague Paul Roberts at the University of California, Los Angeles, created a computer model to simulate the conditions in the Earth's interior.
The computer-generated magnetic field even reverses itself, allowing scientists to examine the process.
Computer Model
Scientists believe Earth's magnetic field is generated deep inside our planet. There, the heat of the Earth's solid inner core churns a liquid outer core composed of iron and nickel. The churning acts like convection, which generates electric currents and, as a result, a magnetic field.
This magnetic field shields most of the habited parts of our planet from charged particles that emanate from space, mainly from the sun. The field deflects the speeding particles toward Earth's Poles.
Our planet's magnetic field reverses about once every 200,000 years on average. However, the time between reversals is highly variable. The last time Earth's magnetic field flipped was 780,000 years ago, according to the geologic record of Earth's polarity.
The information is captured when molten lava erupts onto Earth's crust and hardens, much in the way that iron filings on a piece of cardboard align themselves to the field of a magnet held beneath it.
Most scientists believe our planet's magnetic field is sustained by what's known as the geodynamo. The term describes the theoretical phenomenon believed to generate and maintain Earth's magnetic field. However, there is no way to peer 4,000 miles (6,400 kilometers) into Earth's center to observe the process in action.
That inability spurred Glatzmaier and Roberts to develop their computer model in 1995. Since then, they have continued to refine and evolve the model using ever more sophisticated and faster computers.
The model is essentially a set of equations that describe the physics of the geodynamo. The equations are continually solved, each solution advancing the clock forward about a week. At its longest stretch, the model ran the equivalent of 500,000 years, Glatzmaier said.
By studying the model, the scientists discovered that, as the geodynamo generates new magnetic fields, the new fields usually line up in the direction of the existing magnetic field.
"But once in a while a disturbance will twist the magnetic field in a different direction and induce a little bit of a pole reversal," Glatzmaier said.
These bits of a pole reversal are referred to as instabilities. They constantly occur in the fluid flow of the core, tracking through it like little hurricanes, though at a much slower pace—about one degree of latitude per year.
Typically, instabilities are temporary. But on very rare occasions, conditions are favorable enough that the reversed polarity gets bigger and bigger as the original polarity decays. If this new polarity takes over the entire core, it causes a pole reversal.
"It's a very complicated, chaotic system, and it has a life of its own," Glatzmaier said.
Weak Spot
Peter Olson, a geophysicist at Johns Hopkins University in Baltimore, Maryland, said scientists can now pinpoint the core-mantle boundary where these instabilities in the magnetic field are happening.
One such disturbance Olson has been observing recently formed over the east-central Atlantic Ocean. Like a little hurricane, the anomaly swept toward the Caribbean and is moving up in the direction of North America.
"It's a new one, a little thing," Olson said. "Time will tell whether it develops into something significant. But it is here in the North Atlantic, moving towards the Pentagon. We can track it over the next couple of decades."
Instabilities such as this, Olson added, are causing Earth's magnetic field to weaken. Today the field is about 10 percent weaker than it was when German mathematician Carl Friedrich Gauss first began measuring it in 1845. Some scientists speculate the field is headed for a reversal.
You can see right there that this guy is wrong and doesn't understand what he is talking about, At the Curie temperature iron will lose its ability to be permanently magnetized, but it is not the magnetization of the outer core that causes the Earth's magnetic field. The current theory states that the magnetic field of the earth is caused by electric currents flowing in the outer core. Molten iron can still conduct electricity. So the outer core can produce a magnetic field without being magnetized itself.
There is a very simple explanation for this. There never was a Tesla electric car.
The article doesn’t explain why it happens, just that there’s these “little disturbances”.
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