Talk:Earth's magnetic field/Archive 1

Archive 1

Archive 2

Magnetic field weakening

This is scaring me. If the Earth's magnetic field is getting weaker because of a possible reversal in progress, does this mean that all life on Earth could be extinguished? Denelson83 19:32, 16 Jan 2004 (UTC)

No, Earth's magnetic field has reversed hundreds of times in the geologically recent past without even causing mass extinctions, let alone exquinguishing all life. IIRC, the main effects will be shorter satellite lifespan (the magnetic field protects Earth orbit from radiation) and auroras that will be visible all over the world. The first is an annoying economic problem, and the second should be downright pretty. Earth's atmosphere is sufficient to block harmful radiation all on its own. Bryan 02:02, 16 Mar 2004 (UTC)

But I was told that if the Earth's magnetic field is absent, then the solar wind itself would have a chance to start eroding the Earth's atmosphere. Denelson83 03:42, 16 Mar 2004 (UTC)

It'd start, but the field would only be down for a few years and the amount of erosion that could happen in that period of time is negligible. Bryan 03:52, 18 Mar 2004 (UTC)

You should be more worried about global warming and ozone depletion. Lirath Q. Pynnor

It is highly unlikely for the magnectic field to be going weaker and weaker. thus if it is out for a few years, we will be already cooked. We cannot survive without the magnetic field.Lirath Q. Pynnor

I don't know if the solar wind would "erode" Earth's atmosphere; it is more likely Earth would gain a little hydrogen from the solar wind. The amounts involved would be tiny. The fact that we exist is an indication that there has not been a fatal problem during the many previous reversals. And the ozone layer would probably produce more shielding because it would get thicker, with stronger magnetic fields being induced within the ionosphere. We'll have to update Wikipedia then. (SEWilco 05:36, 14 Mar 2005 (UTC))

The net effect is definitely to deplete the atmosphere, but even if the magnetic field just quit entirely, the relevant time scale is a few billion years, so nothing to worry about. I wouldn't expect the ozone layer to change much because it is dominated by UV effects not energetic particles. Dragons flight 05:57, Mar 14, 2005 (UTC)

Look the ozone layer has nothing to do with this. Now why would anybody worry about the magnetic field now? Plus, once it stops, the magnetoshere will drop. Solar winds will blast through our atmosphere,all layers of repellents will be useless.The earth will come to an end when that happens. User:Conrad Zhimmsky

Although that comment is not coherent, the solar wind is too thin to "blast through our atmosphere", and the earth has not "come to an end" during the many previous times the magnetic field has reversed. (SEWilco 14:06, 28 September 2005 (UTC))

A note for the curious. Even an unmagnetized Earth might have a magnetic field. Birk et al. show how this could happen in their 2004 article in Astronomy & Astrophysics (Vol. 420, L15-L18). You can find the article at arXiv ([1]).--Octupole 21:31, 16 December 2005 (UTC)

Does this mean that anything unmagnatized(say a battery)could have a weak magnetic field? —The preceding unsigned comment was added by 24.62.12.142 (talk) 15:59, 18 March 2007 (UTC).

Error (Magnetic Field Decay)

I believe it is incorrect to say that the earth's magnetic field began weakening 150 years ago.

It was 150 years ago that regular measurements of the earth's magnetic field and over the last 150 years there has been a continual drop in the strength of the field totally 10%.

Without measurements or some other evidence, we cannot say anything about the strength of the earth's magnetic field prior to 150 years ago.

Saying that it started to drop 150 years ago suggests that the field was steady or increasing up until 150 years ago and suddenly went into decline 150 years ago. However, the figure of 150 years ago is not the time whe it started to decline but the time when regular measurements were first taken and hence when it became possible to ***notice*** the decline.

A more correct statement would be: In the last 150 years, since regular measurements of the strength of the earth's magnetic field began to be recorded, the strength of the earth's magnetic field has dropped by about 10 percent.

I don't know when the Earth's field began it's current decline, but I do know that there are abundant measurements of paleointensity based on the remnant magnetization in lavas. Lavas lock in the magnetic field direction and intensity at the time when they solidified. I forget at what point that record shows the current decline beginning but I do remember that the highest intensity in the last several thousand years occured circa 1 AD (give or take a hundred years). Dragons flight 08:19, Dec 6, 2004 (UTC)

I included a paleogeomagnetic graph that gives an idea of how much the field strength has varied (stronger and weaker). Feel free to add encyclopedic explanations. (SEWilco 17:07, 14 Mar 2005 (UTC))

The earth's magnetic field was measured by Gauss in 1835 and has been repeatedly measured since then showing an exponential decay with a half-life of ~1400 years. The data has been published in numerous places but i will try to upload a table with the measurement dates and values. Kenny56 04:26, 27 December 2005 (UTC)

What about why it is weakining? Could it be that magnets and/or supermagnets inside the atmosphere are damaging it? Or could it be the force of the solar wind demagnetizing the field? —The preceding unsigned comment was added by 24.62.12.142 (talk) 16:04, 18 March 2007 (UTC).

That's pure hogspit. The cause of long period fluctuations is the geodynamo.

Dynamo theory

The text needs— for well-meaning simpletons like me— just the briefest characterization of dynamo theory as it relates to generation of the Earth's magnetic field, to make the picture more complete. A paragraph headied Main article: dynamo theory. is one well-tried way to do this. --Wetman 08:22, 14 Mar 2005 (UTC)

I think the real problem here is that "Dynamo Theory" is bunk. In the current article, it describes a "reinforcing field" which is powered only by the original field, which the "reinforcing field" is apparently stronger than, and reinforces. Can anyone say "perpetual motion machine"??? What is really needed is for someone to write a section entitled "cause of the geomagnetic field", and really answer the question. But maybe nobody actually knows the answer. (???) If not, then a section entitled "hypotheses for causes of the geomagnetic field" might be a better choice. SJGooch (talk) 04:05, 23 February 2011 (UTC)

Telluric currents

You contradict yourselves here as when I looked up the Earth's magnetic field, it stated that it was created from telluric currents, however when you look up telluric currents it states that these are effected by the earths magnetic field... So what came first the chicken or the egg? This isnt the only web site to make this same contradiction, which makes me wonder which is true?

Wikipedia does not contradict itself. It states that the magnetic field drives the currents, and that the currents drive the magnetic field. These statements are both true. It's a self-sustaining system, of which there are many more examples in nature and in technology. Wikipedia does not say that they both came first.

The answer to "which came first?" is (according to the dynamo theory) as follows. In the beginning, the Sun's magnetic field induced currents in the Earth's mobile, conductive liquid core. Those currents created the Earth's magnetic field, which then came to dominate the Sun's field near to Earth. Therefore, it is now mainly the Earth's magnetic field that drives the telluric currents, which in turn maintain the magnetic field.

In case I seem to be defending Wikipedia too aggressively, let me admit that we do seem to have a circular definition, which ought to be fixed. --Heron 20:28, 26 September 2005 (UTC)

Hi folks! I'm a visitor on this page, but as i come from geomagnetic background there are a few things a would like to mention:

1) the Earth's magnetic field is NOT created by telluric currents! It is created by currents in the liquid outer core (as mentioned in an paragraph above) but that are not telluric currents. telluric currents are induced in the crust / mantle by electromagnetic waves from the atmosphere - due to thunderstorms, e.g., or (as mentioned in the article about telluric currents) solar wind or currents in the ionosphere. changes of the main field, that is the field generated in the deep interior, are much to slow to induce currents in the crust or mantle. they occur over time scales of years rather than days or even hours. if you have further questions, don't hesitate to contact me: reyko@gmx.net (subject should include "wikipedia").

Thank you for making that clear. I stand corrected. --Heron 19:33, 30 September 2005 (UTC)

"Magnetic field electrogenerators"

The Earth's capacitance was proposed as a source of electrical power, not the Earth's magnetic field. I suggest that the section on Magnetic field electrogenerators should be eliminated. Michael H 34 14:05, 12 June 2007 (UTC) Michael H 34

"Some free-energy enthusiasts claim that the Earth's magnetic field could be used to generate power[4], but such claims are regarded as pseudoscience by many skeptics."

This sentence is not supported by the citation. As noted in the title of the citation, the Earth's electric field is a proposed source of power. Michael H 34 14:09, 12 June 2007 (UTC) Michael H 34

"There is also some energy stored in the form of separated electrical charges, which can provide low direct currents at high voltages."

This is incorrect. Capacitors (separated electrical charges) must run on AC not DC. Michael H 34 14:12, 12 June 2007 (UTC) Michael H 34

Bunk! If you have a charged capacitor, and you short it out, a transient current will flow. Period. Characterizations of only "AC" or "DC" applying to capacitors are nonsense. A capacitor is an electrical component. Put it in a circuit, and it will behave as physics dictates. Physics doesn't distinguish between some arbitrary label of "AC" or "DC". It just acts to counter the charge imbalance. Separated electrical charges certainly harbor potential energy. Lightning proves this every time there is a thunderstorm. — Preceding unsigned comment added by Sjgooch (talk • contribs) 04:15, 23 February 2011 (UTC)

Improvements

This article needs improvements. For example:

• What's the difference between the Earth's magnetic field and the surface magnetic field?
• Where was the 1043 K temperature for the Core taken from?
• Even though the temperature in the Core makes it lose its permanent magnetization, it doesn't mean that the geomagnetic field is not caused by magnetized iron deposits. There are magnetized iron deposits in the Crust contributing to the observed magnetic field. However, their contribution is very small compared to the core-generated field.
• Where was the exponential decay with a half-life of 1400 years taken from?

Not to mention many others. --Octupole 17:59, 21 January 2006 (UTC)

• What is the purpose and benefits of earth's magnetic field?
• More links on earth's magnetic field research.
• What is damaging Earth's magnetic field?

THIS ARTICLE NEEDS IMPROVEMENTS? Get rid of these stupid talk pages. They are not scientific. All they are is misinformed laymen tossing out opinions which lack any supportive facts or documentation.

This is nothing more than a chat room page. A true disgrace to Wikipedia. If someone wants the facts regarding Earth's magnetic field or any other scientific subject, who in their right mind would EVER come to a talk page for that information?

Nobody in their right mind. These talk pages are nothing more than a waste of cyberspace. Get rid of this crap ASAP to save any credibility towards the real crux of Wikipedia before it's too late and Wikipedia becomes an unreliable source for ANY information! —Preceding unsigned comment added by 71.87.58.90 (talk) 07:23, 22 October 2008 (UTC)

Image not to scale?

The image caption for the main picture currently says it is not to scale. This is confusing because the relative sizes of the Earth, the magnetosphere and the Sun are to scale. What is not to scale is the distance between the Sun and the Earth. Does anyone agree with this? If so, I will change the caption accordingly. Carcharoth 10:20, 25 August 2006 (UTC)

Oops. I confused Jupiter and the Sun. Jupiter's diameter is about 10 Earths, but the Sun is about 100 Earths. So the Sun and Earth are not to scale here. Still, I think the magetosphere and the Earth are to the same scale, so that needs to be made clear. Carcharoth 13:24, 25 August 2006 (UTC)

Well, one could say the image is locally to scale, but that would be too confusing. The purpose of the image is to establish the rough shape of the magnetic field, rather than to provide an accurate depiction of what it really looks like, so the scale variability really isn't an issue. —Preceding unsigned comment added by Virogtheconq (talk • contribs)

georeactor theory misrepresented?

The abstract of the following inline link does not mention iron nor its absence:

One theory does contend that the core of the Earth is not iron but much denser atoms.

I have no access to the full paper, but the claim looks doubtful, ie. I believe the paper does not in fact claim there is no iron, and instead proposes nuclear reactions as a source for some of the heat energy in the core. Could anyone check this?

The paragraph continues with more doubtful, or possibly oversimplified, claims:

Nuclear reactions as replicated in a fast breeder reactor are suggested to take place and this accounts for the change in the Earth's magnetic field.

Without the full paper I can only speculate that the paper proposes that variations in the hypothetical geo-reactor somehow switch the dynamo effect on and off. Again could someone check whether the claim needs rewording? -213.219.184.15 16:46, 20 October 2006 (UTC)

You do have access to the full paper. It's a PNAS document. Click on one of the full text links. An actinide subcore is proposed. (SEWilco 19:34, 20 October 2006 (UTC))

Earth Magnetic Field

The Earth Magnetic Field getting weaker,

Is that means the direction of magnetic flow will be reversed? If that true, it means the sunrise will be from west, and the sunset will be from east? —Preceding unsigned comment added by 64.12.116.10 (talk) 7:48, 30 October 2006

The Earth should still rotate in the same direction, so North America's sunrise will still take place in the direction of the Atlantic. The definition of "East" and "West" is dependent upon international standards rather than where a compass points. Maps are defined based upon the poles of rotation, we're not changing GPS coordinates based upon the wanderings of the magnetic poles. (SEWilco 21:45, 30 October 2006 (UTC))

What would happen if it were to reverse? like what events wuld happen?

Rapid-decay theory

This may be bunkum and probably is. However, it is an internal link that is relevant to the article and should remain while there is an article. If it is worth an article it is worth a link. If you are not happy, put it up for AfD rather than trying to conceal its existence. BlueValour 01:40, 8 November 2006 (UTC)

If your feel that it probably is - bunkum, then why are you pushing it. If anything, it is either pseudoscience or some creationist dream. Doesn't rate a link from this or any science article. Vsmith 03:23, 8 November 2006 (UTC)

I am not pushing it - simply that it is a published and widely circulated theory and therefore merits a place in Wikipedia. Theories get articles not because they are true but because they are verifiable. This is shown by one of the references that sets out the case against it! Articles should have all relevant internal links, whether or not you or I might disagree with them, for NPOV reasons. Had I been pushing the article I would have added its content to this article - I haven't but a link is the minimum we should do and is not undue weight. BlueValour 03:33, 8 November 2006

Someone mentioned to me the exponential decay, seemed a bit odd. So I looked it up and came across this. http://www.talkorigins.org/faqs/magfields.html

This article talks about exponential decay much more succinctly: http://www.talkorigins.org/indexcc/CD/CD701.html Additionally, based on the figure shown in the "Magnetic field variations" section, it appears that the whole "magnetic decay" idea as a long-term trend (and especially the one when paired with the idea of exponential decay) seems to be completely erroneous. You can't fit a decay line or an exponential decay line into that figure. - BC, Jan24, 2007

cobaltnova: I am adding a reference to http://www.geocities.com/CapeCanaveral/Hangar/2437/magnetic.htm in hopes of balancing the views of this section.

really really needs work

The stuff about exponential decay is wrong, the stuff about geomagnetic generators of energy is nonsense, the stuff about two-ended cathodes to get AC is laughable. The beginning is OK, but the page degenerates into bad sci-fi.

I realize that those comments are all negative, and no help, but someone who knows the subject needs to clean it up, which could be done by simply excising all the non-science. I'm a physics professor (so I recognize garbage science when I see it), but am not a geophysicist, so I wouldn't try to write an article about this subject. There are plenty of people who could.

Hallewis 07:47, 24 February 2007 (UTC)

which pole is positive and which is negative?

The stuff about exponential decay is clearly ridiculous. I'm not going to rewrite this article myself as I don't have the time but someone should rw-write it definitely. --ScienceMind (talk) 19:39, 26 July 2008 (UTC)

Headline text

Bold textWHICH POLE IS POSITIVE AND WHICH IS NEGATIVE?

The south pole is "positive" and the north pole is "negative", that is if the earth was creating an electic field and not a magnetic field which it really is. Happy? 71.112.127.91 04:41, 22 May 2007 (UTC)

Improvements

== Few thousands years the strengths of the global magnetic field of earth, - has decreased. Now a days we are doing exactly measurements, especially the last 10 years. - BUT there is nowhere at the internet (so fare I have seen) where it is possible get information about how much the global magnetic strengths of earth really is decreasing (or increasing) year by year (or better month by month). I suggest such information to be added to this article. == —Preceding unsigned comment added by Bjarne Lorenzen (talk • contribs) 10:00, August 29, 2007 (UTC)

Is it possible that Earth's Magnetic field due to Polar ice blocks ?

It's just a question whether the features of Earth's magnetic field is due to polar ice.

If Earth's magnetic field is caused by liquid iron in core, it should be fairly stable over long period of time. I guess it may be some other unstable matter - the polar ice. Water molecule is polar but all magnetic vector cancel out in liquid form. When ice forms, may be there is some aligment of crystal getting an advantage. Earth spins and makes typhoon or drainage water whirling in certain directions. So as a certain portion of polar ice is aligned . When crystal forms, some aligment of molecules is just a little bit advantageous. And the advantageous alignments near North Pole and South Pole are just opposite in direction.

Ice blocks in two Poles are very huge and consist of huge amount of aligned molecules. Both two Poles having huge ice blocks strengthen the magnetic fields so caused. Sometime in Earth's history ice block grew and melted and changed the strength of magnetic field, even 'lost' in short period. When ice in North hemisphere melts, ice in South hemisphere grows. So we do not notice seasonal change of field strength. When Earth gets hot, ice in both two Poles melts and we have weaker field today.

Not only two Poles have ice, but also other continents. We have more ice covering land in North hemisphere than in the South. The ice is not evenly distributed across the longitudes. This may be the reason of missaligned of 11 degrees of magnetic north.

Is it possible ?

Lau Tak-man (talk) 14:11, 13 April 2008 (UTC)

Magnetic field reversals or other variations have no correlation whatever with glacial or other climatic conditions. Cheers Geologyguy (talk) 14:37, 13 April 2008 (UTC)

{{reqdiagram}}

Hi, I'm commenting out this template as this article has several illustrations (plus more at Commons). If a specific diagram is requested, please re-add it with details about what is wanted. thanks --pfctdayelise (talk) 13:03, 27 July 2008 (UTC)

Reversal Quickening

This Finnish governmental news org is reporting speeding of the movement of north magnetpole from it's usual 10km/year to 50km/year. It will reach geologic north pole in 2018 unless it stops or speeding increases. According to the professor Heikki Nevanlinna during the last 5 000 000 years magnetpolarity has changed some 20 times, which makes the cycle of abt 250 000 years.

On 2001-2002 it was reported the north magnetic pole would reach geonorth by 2050 but apparently the time frame has narrowed a lot.

In the article it also says that across earth's magnetic field small shifts has already occured which means the big shift is on due anytime now. Helloworld2k (talk) 06:34, 14 August 2008 (UTC)

Can't we do flying vehicle....

As we all know,if we bring the opposite poles of two magnets,they repell each other. By using the same concept can't we do a flying vehicle,which opposes the earth,s magnetic field,by using required amount of magnetic field in the vehicle ? Plz think well and answer as soon as possible.. Thank you.. —Preceding unsigned comment added by 210.212.192.18 (talk) 12:01, 11 September 2008 (UTC)

I have had similar thoughts before. The main problem is that the magnetic field points in a different direction than gravity virtually everywhere on the Earth's surface. If you had some kind of craft that generated an extremely strong magnetic field (compared to its weight), it would not move straight up, but would either attract or repel the nearest magnetic pole at an angle to the ground. Any lift produced would be accompanied by an even stronger tendency to fly toward one of the poles horizontally. CosineKitty (talk) 02:22, 13 February 2009 (UTC)

A Magnetic Field Question.

Hi, first of all sorry for my english.. i was just wondering about something i have in my head from a little time.. I wanna mean that rotation of earth and rotation of magnetic field, probably is not so fluid like we common suppose. I arrive at this conclusion just watching and watching again some objects just under our nose, and beleive that most of things we suppose round, are in fact really matematically shaped, by at least -3 main magnetic forces-, perpendicular to the earth axis. Let me make u some example to explain. if we look closer to a snow-flake , we can clearly notice an Hexagon shape. That is probably made by 3 pulling forces. If we look to a bee house, we can look Hexagon again -the same shape-. But is not finish. When we cut a lemon, or an orange, we can also see the fruit, has developed itself in some mathematic shapes, the segments, and again some plants and flowers, develop themselves in regular shapes. Looking closer a fly flying around a light, and tracing its way, u can also see it turn around in some straight lines, not continuously round, but changing the way immediately, like follow a scheme. So if anyone has some explanation I am really curious to know why, and especially when we think that also inside atoms,scientist discover there are 3 main charges..with 3 lines,u can make an hexagon.(don't forget recently picture of hexagon cloud on saturn.).Thanks in advance to who want to go on.bye. —Preceding unsigned comment added by 79.44.122.173 (talk) 08:34, 16 March 2009 (UTC)

Self-organization in nature. Self-organization of nature. How matter organizes itself.

In a talk page about the Earth's magnetic field. OK, cool!

Yeah, those convection patterns on Saturn are pretty cool too. Patterns appear, self-organization happens. Large patterns like that can be explained by small scale dynamics and simple non-linear math. Feedback. The geodynamo self-organises too.

Magnetic field is not caused by molten iron core but by ocean's?

see: [2]

,,Now, Gregory Ryskin of Northwestern University, Illinois, is offering an alternative explanation for the origin of this secular variation. Ryskin believes that electric currents induced in dissolved salts — as ocean waters circulate through the Earth’s magnetic field — can generate secondary magnetic fields strong enough to shift the orientation of the original field.

Food for thought and inclusion as debatable content or is it too early since there is still lots of opposition to this idea?

Rabhingm (talk) 06:57, 15 June 2009 (UTC)

What exactly is it that causes polarity reversal?

I would like to see some more information on what causes the reversal of polarity detected in these rock formations. Is it caused by core dynamics and or the migration of the poles? Or is something else responsible. Could it be caused by Solar flares stripping the field perhaps, leaving a 50/50 chance of a reversal occurring? Is it a combination of things. What evidence is in the rock formations of the time frame of these reversals, eg. do they change very quick or is it a gradual process.  —Preceding unsigned comment added by S Burst (talk • contribs) 00:26, 5 October 2009 (UTC) 

Line joining the magnetic poles

An imaginary line joining the magnetic poles would be inclined by approximately 11.3° from the planet's axis of rotation.

No reference or explanation is given. How was this calculated? Given the 2005 values (north magnetic pole 82.7°N 114.4°W, south magnetic pole 63.1°S 137.5°E), drawing that imaginary line, and solving its angle with Earth's axis (using dot product of the two vectors), I get something like 15.1°. --Jmk (talk) 08:59, 6 October 2009 (UTC)

Well, no citation or explanation has appeared for the 11.3°, so I removed it. --Jmk (talk) 10:13, 26 October 2009 (UTC)