Ocean Currents Proposed As Cause of Magnetic Field

pjt33 notes a recently published paper proposing that ocean currents could account for Earth's magnetic field. The wrteup appears on the Institute of Physics site; the IOP is co-owner, with the German Physical Society, of the open-access journal in which the paper appears. This reader adds, "The currently predominant theory is that the cause of Earth's magnetic field is molten iron flowing in the outer core. There is at present no direct evidence for either theory." "Professor Gregory Ryskin from the School of Engineering and Applied Science at Northwestern University in Illinois, US, has defied the long-standing convention by applying equations from magnetohydrodynamics to our oceans' salt water (which conducts electricity) and found that the long-term changes (the secular variation) in the Earth's main magnetic field are possibly induced by our oceans' circulation."

Comments

Could be...

[houstonbofh]

There is enough junk floating on the oceans that the currents could be ferrous.

Re:Could be...

[Anonymous Coward]

So are you saying the ocean is a ferrous wheel?

Re:Could be...

[fahrbot-bot]

So we're talking about _electric_ ocean currents? How is right hand rule newsworthy?

Um, this is /. so I'm not sure "right-hand rule" always means what you think it does here. :-) I'm sure a lively debate could ensue on "science geek" vs. "lonely geek".

Re:Could be...

[Anonymous Coward]

Lonely geek has moved on to the Fleshlight rule.

Re:Could be...

[Nefarious Wheel]

No.

Re:Could be...

[sycodon]

Interesting. What ferrous material floats (that is in the category of "junk")?

Re:Could be...

[houstonbofh]

A shipping container, for one.

Polarity switch

[indre1]

So basically we know that global warming has taken over our ocean's currents when our compasses start pointing to the south...

Re:Polarity switch

[Anonymous Coward]

It'll be the magnetic North pole... North just wont be where you think it is.

Re:Polarity switch

[Killer Orca]

No, the poles already reversed once in theory http://en.wikipedia.org/wiki/Earth's_magnetic_field, and are likely to keep reversing, though none of us will be around to find out.

Re:Polarity switch

[mustafap]

>and are likely to keep reversing, though none of us will be around to find out.

And I doubt that the people around at the time will be around to find out either :o)

Re:Polarity switch

[atheistmonk]

What we need to do is reverse the polarity of the neutron flow.

Re:Polarity switch

[vulpinemac]

No, the poles already reversed once in theory http://en.wikipedia.org/wiki/Earth's_magnetic_field, and are likely to keep reversing, though none of us will be around to find out.

If you do some non-wiki research, you will find out that Earth's magnetic field has reversed many times over the eons. We're overdue now by several thousand years. This Global Warming may be just another indicator that such a change is imminent.

Re:Polarity switch

[dziban303]

though none of us will be around to find out.

Jesus will be.

Re:Polarity switch

[pnewhook]

Well magnetic north has moved over 1100 kilometers in the past 100 years, and the motion is accelerating. It is currently moving about 40km per year.

Re:Polarity switch

[Daychilde]

I"m trying hard to make a joke about writing down when it happened and referring to that as reverse pole-ish notation, but... I think I'll let it go.

(I should probably post this anonymously, but hey - I stand by my bad puns!)

Re:Polarity switch

[Randle_Revar]

>No, the poles already reversed once in theory

No, the magnetic poles have reversed a great many times as can easily be seen in the changing domain alignments in crust created over time around mid ocean ridges.

Re:Polarity switch

[RockDoctor]

If you do some non-wiki research, you will find out that Earth's magnetic field has reversed many times over the eons.

Hundreds if not thousands of direction changes are documented, back into the Triassic at least and possibly into the Late Palaeozoic. There are sufficient that, in more recent times (Cretaceous onwards) the reversal record has been used as a tool for correlation. (Such work may go back further into the geological record ; I've certainly seen it used in Cretaceous mudrock sequences as a petrophysical indicator that can be measured faster and with less skilful operators than other techniques like palynology.)

We're overdue now by several thousand years.

For certain values of "overdue" ; the distribution of durations between reversal events seems to be essentially random, and since we're over the average duration between reversals, then one could meaningfully "expect" a reversal sooner rather than later. But once you start looking at the statistics, you have to accept that, if the model is accurate, then the probability of a reversal in the next thousand years (say), is the same as the probability of a reversal in the first thousand years after the last reversal. It's the same logic as tossing coins - if you get ten heads in a row, the probability of your next toss being a head is still 1/2, even if the probability of getting 11 heads in a row is 1/2048. Random variables - love 'em or hate 'em, but you can't predict 'em.
That said, outside the statistical description of the record, the physical models suggest that some events seen at the moment (decreasing field strength ; regional anomalies) may be precursors to a reversal.

This Global Warming may be just another indicator that such a change is imminent.

Has someone been claiming global warming to be related to magnetic field strength? Whooo, can I get a smoke of that? Sounds like good gear.

Re:Polarity switch

[digitalchinky]

Your link to wiki says that magnetic reversal appears to have happened (once all the geology is averaged out) every 250,000 years. I'm not seeing anything indicative of this having only ever happened once. The last time this event may have occurred was 750k years ago, so why is it none of us would be around to find out about the next one?

Am I missing something here?

Re:Polarity switch

[randalny]

No, the poles already reversed once in theory http://en.wikipedia.org/wiki/Earth's_magnetic_field, and are likely to keep reversing, though none of us will be around to find out.

This is not really a theory at this point. It has been demonstrated clearly in the geologic record that the earth's polarity has completely reversed at least hundreds of times (as wikipedia notes, "at an average interval of approximately 250,000 years").

Re:Polarity switch

[Will.Woodhull]

It would be interesting to look for correlations between magnetic reversals or similar anomalies, and geologic events that must have had a major impact on ocean currents. Such as the formation of the Isthmus of Panama roughly 3 million to 10 million years ago (I don't know enough geology to understand why different articles use different figures), and the separation of South America from Antarctica about 40 million years ago.

Re:Polarity switch

[Ungrounded Lightning]

But last I heard it moves essentially in a circle or otherwise wanders around near the rotational north pole, rather than heading south for the winter.

So how fast it's moving is no big deal - but a change in the direction of its motion might be.

Re:Polarity switch

[pnewhook]

Doesn't look like a circle to me... http://gsc.nrcan.gc.ca/geomag/nmp/long_mvt_nmp_e.php

Re:Polarity switch

[Ungrounded Lightning]

I stand corrected.

(But it is moving more NORTH at the moment.)

Re:Polarity switch

[RockDoctor]

It would be interesting to look for correlations between magnetic reversals or similar anomalies, and geologic events that must have had a major impact on ocean currents.

If I understand the article correctly, the largest effects would be from ocean currents running North-South, so the opening of E-W trending barriers would be the events to look for. Whether you'd get sufficient resolution more than a couple of million years ago though ... hmmm.

Such as the formation of the Isthmus of Panama roughly 3 million to 10 million years ago (I don't know enough geology to understand why different articles use different figures)

I don't know that area in detail, but here is a scenario :

• Fred is a geologist looking at ocean floor deposits formed below 2000m depth (the carbonate compensation depth, approximately) ;
  Fred sees the Isthmus close 10 million years ago, as the seabed level between Atlantic and Pacific rose above 2000m below MSL, and the creepy crawlies that Fred looks at can't cross between the newly-isolated Pacific and Atlantic basins.
• Meanwhile, in the same area, George is looking at coral communities which form mostly in the photic zone (less than 200m depth) ;
  George sees the basins become separate (and to start developing endemic elements to their fauna) at 3 million years ago, when the water depth decreased through 200m to 0m and then to negative numbers.

Fred and George see the Isthmus close at different times because the objects of their study have different environmental tolerance ranges.

The same logic could easily apply to the question of ocean currents for the purposes of this hypothesis of the magnetohydrodynamics of seawater. The currents cited in the article are all surface currents, but it is (to me) credible that what would be most important might be the deep ocean circulation, which is generally slower but broader. This would have non-intuitive effects - for example the presence of the huge mountain range down the middle of the Atlantic Ocean could well have a significant effect, by forcing the deep circulation into more North-South routes than the surface circulation uses.

Re:Polarity switch

[Bigjeff5]

Which means the fact that the pole is moving further north is difinative proof that global warming is a hoax!! :P

I may be wrong, Im not an astrologer

[edittard]

Aren't there planets that do have magnetic fields, but don't have oceans? And aren't there moons that are the opposite case?

Re:I may be wrong, Im not an astrologer

[gardyloo]

I can pretty much guarantee that astrologers would have no idea what you're talking about :)

Re:I may be wrong, Im not an astrologer

[Creepy Crawler]

That's correct. According to their theory, moons like Europa should have a rather strong magnetosphere.

Europa is believed to have a warm, salty ocean under the ice crust. And yet, it shows only slight inducted magnetic field from Jupiter. Contrast that with Ganymede, the only moon with its own magnetosphere and a liquid iron core. Satellite photos dont show very much (or any) water on its surface.

Hmm.

Re:I may be wrong, Im not an astrologer

[VampireByte]

I may be wrong, Im not an astrologer...

If you ask an astrologer a question about the ocean, they'll probably want to know if you're a pisces.

Re:I may be wrong, Im not an astrologer

[Gravedigger3]

My question is how the hell can they determine all this information about other planets when we can't even figure out exactly what makes our own planet tick?

Re:I may be wrong, Im not an astrologer

[im_thatoneguy]

Europa's ocean may not have strong currents though. Also there could be multiple causes that don't match every planet. Our sample size is pretty small on the subject. Ganymede might have a magnetic field due to its liquid iron core. And we might have a magnetic field due to our oceans. And Planet X might have a magnetic field due to something else all together.

Re:I may be wrong, Im not an astrologer

[Creepy Crawler]

The idea of the ocean under Europa is that of an educated guess based upon tidal forces between Jupiter, and the fact that surface composition of Europa is frozen water. Flyovers have taken spectral pictures indicating that fact. They also have taken magnetic force readings and determined that any form of magnetosphere was Jupiters creating.

Ganymede has a liquid iron core, from which I dont understand how they figured that out. However, many sources say so, including NASA. And it's noted by the natural color of 'streaking on the ice' that the moon does have its own magnetosphere. And it was measured by Flyovers. It's strange that it still has a liquid iron core, al most over planets have frozen. The assumption is that Jupiter tidal forces have insulated it.

We dont need to understand why and how a liquid iron core creates a magnetosphere. We CAN measure more data points to see if our hypothesis matches with known facts. And this water-creates-magnetosphere seems debunked.

Re:I may be wrong, Im not an astrologer

[Bungie]

Aren't there planets that do have magnetic fields, but don't have oceans?

IIRC Venus has a weak magnetic field and does not have an ocean.

Re:I may be wrong, Im not an astrologer

[Iron Sun]

Mercury has a magnetic field, which quite surprised planetary scientists when it was first discovered by MAriner 10, as the prevailing theory at the time was that Mercury's small size would have led to its core solidifying by now and stopping the dynamo that generated the field.

There's obviously a lot we don't know about planetary magentic fields, and I wouldn't want to judge the entire theory just by something I read on Slashdot, but I find it hard to understand how oceanic currents could account for Earth's magnetic field but not for Mercury's.

Re:I may be wrong, Im not an astrologer

[defireman]

Depends. But lacking an ocean will not preclude a planet from getting an magnetic field - there could be other factors at work here.

Re:I may be wrong, Im not an astrologer

[icebike]

As does mars. It has a weak field, but it also is suspected of having a much smaller molten core.

Europa and Ganymede have molten cores due to gravitational churning.

So far, molten cores correlate well with magnetic field strength. Oceans, when present, tend to be on those bodies having molten cores, but their absense does not entirely preclude a magnetic field.

Re:I may be wrong, Im not an astrologer

[MrMista_B]

Yes. Fortunately, as usual, the summary has /nothing to do/ with the /actual/ article that it's referencing.

Re:I may be wrong, Im not an astrologer

[Brian Gordon]

The tenets of an ancient religion are as valuable as a plausible educated guess?

And this situation is completely different from gravity. We know exactly how gravity behaves and can model it perfectly (well, until you get down to the quantum level). We just don't have a very good way to break it down like we've been able to do with the other 3 fundamental interactions. In the case of the Earth's magnetic field, we don't know what generates it and we don't know why it changes direction, but there's nothing magic or fundamental going on like with gravity; it's just a difficult problem in geology.

Re:I may be wrong, Im not an astrologer

[DJRumpy]

Actually there is no proof at all that God exists (read: 'faith'). There is plenty of mathematical evidence to explain gravity. We may not be able to reproduce it directly, but it is most certainly measurable and quantifiable.

The theory of gravity is just that. A theory. It has gone beyond a hypotheses.

Unless something more 'provable' comes along, it will remain the dominant theory. It's unlikely that 'God's Gravity Hypothesis' will oust it any time soon.

Re:I may be wrong, Im not an astrologer

[gardyloo]

On another note, I don't believe he said he believed that god did anything, he said that it was just as valuable as the current explanation.

      You may be right about the first point. However, reading some of his other postings on slashdot, he seems to take every opportunity to get some mention of a creator shoved into his comments, and I'd be willing to bet that this time is no different.
      As to the second point, if he really was saying that, it's a big Logic: Ur doin it rong failure on his part.

Re:I may be wrong, Im not an astrologer

[Korin43]

I wonder if the idea that Ganyemede has a liquid iron core is based on the assumption that only liquid iron cores cause magnetic fields?

Re:I may be wrong, Im not an astrologer

[Gerzel]

Just as valid as a hypothesis perhaps, but not as a theory.

A theory requires some evidence and logical reasoning.

While scientists don't "truly know" in that their knowledge is incomplete; they do have a large body of clues, expirmentation and evidence to help them build a more complete knowledge.

You on the other hand simply have given your hypothesis without bothering to look at any clues further than your own skull, or at least you haven't bothered to publish or explain your clues and reasoning to others in any fashion, least of all a repeatable, verifiable fashion that is required for rigorous science.

Thus good scientific theory is indeed more valid than your unsupported hypothesis.

Re:I may be wrong, Im not an astrologer

[Gerzel]

He did imply his belief by claiming it to be his assertion.

Re:I may be wrong, Im not an astrologer

[Gerzel]

It is a lot simpler on other planets as you often don't have quite as many things crawling around on top of them.

Also they provide other points of reference allowing us to compare our planet with theirs.

Re:I may be wrong, Im not an astrologer

[Kratisto]

Perhaps he is only playing Devil's Advocate (har har irony), but the point he makes is ridiculous: That the postulation of a creator is exactly as valid as a scientific theory constructed from what we currently understand about the Earth. On one hand, we have a scientist hypothesising that the Earth's magnetic field is created by electrical currents in the oceans (or more traditionally, by the spinning of the Earth's Iron core), and on the other hand, we have a creator who is necessarily more complex than the entire Universe and all it's systems just popping into existence and thinking to himself "Gee, it sure would be nice to have worshipers, maybe I'll make a planet of those." The former builds upon our prior knowledge, the latter defies probability.

Re:I may be wrong, Im not an astrologer

[Jarik C-Bol]

the real problem with the molten iron core theory, happens to be, as any good metallurgist can tell you, that iron becomes non-magnetic at temperatures far cooler than required to actually melt iron. now, i am not a geophysicist, but i get the feeling that this throws a rather large wrench into the theory.

Re:I may be wrong, Im not an astrologer

[vulpinemac]

Mercury has a magnetic field, which quite surprised planetary scientists when it was first discovered by MAriner 10, as the prevailing theory at the time was that Mercury's small size would have led to its core solidifying by now and stopping the dynamo that generated the field.

There's obviously a lot we don't know about planetary magentic fields, and I wouldn't want to judge the entire theory just by something I read on Slashdot, but I find it hard to understand how oceanic currents could account for Earth's magnetic field but not for Mercury's.

One piece of logic disrupts the idea that Mercury would have a solid core... It's proximity to the sun gives it a surface temperature hot enough to melt some metals. Granted, the opposite side of Mercury is also the coldest place in the Solar System (due to the planet's lack of atmosphere and equal lack of rotation.) This could, conceivably imply a solid core. However, just like boiling water, if you heat one side and leave the other side cold, you create a thermodynamic flow which could generate a magnetic field even without an orbiting moon to create the tidal current in that core.

Re:I may be wrong, Im not an astrologer

[poopdeville]

You are certainly right about that. If there is no God then you are no more valuable than a cock roach, because all life climbed out of the primordial ooze. Only a personal God can give personal value.

Bullshit.

Value is given by evaluators. In my case, the evaluators are me, and the people who know me well enough to have a valid opinion of me. I don't need a fancy invisible god to see that human beings are more valuable to human beings than cockroaches.

Re:I may be wrong, Im not an astrologer

[gardyloo]

Scientists know that there are many parameters and constants, including the earth's magnetic field, which have to be exactly right in order to have life as we know it upon the earth.

      The operative phrase there is as we know it. Change the constants a little, and other forms of life are perfectly capable of living. You're giving the fine-tuning argument (http://en.wikipedia.org/wiki/Fine-tuned_universe), which is interesting, but it's a tired canard trotted out by creationists time and again, and proves nothing.

      And, yes, I'm a physicist interested in the question. Your quote is disingenuous.

Re:I may be wrong, Im not an astrologer

[GIL_Dude]

Current flow causes magnetism. You can demonstrate that with a non-magnetic copper wire and a battery. The copper doesn't suddenly become "iron like" and have a crystalline structure that responds (is attracted by) to magnetism. It is simply the current flow that causes this.

In much the same way, the molten iron theory is more around currents (fluid currents) causing electrical currents in the core. These electrical currents then cause the magnetism.

Nobody is saying that the iron itself is magnetic (because then it would be magnetite and not iron anyway).

Re:I may be wrong, Im not an astrologer

[arminw]

...Change the constants a little, and other forms of life are perfectly capable of living...

As a physicist you would know that the laws of physics appear to be the same throughout the universe. The binding energies of the carbon atom are just right to make the complex structures necessary for life. There is no other chemistry that we know about that could form any life other than carbon based. Neither scientists nor theologians ever prove anything, but only believe or disbelieve in various facets of their respective discipline.

Re:I may be wrong, Im not an astrologer

[Nefarious Wheel]

I may be wrong, Im not an astrologer...

If you ask an astrologer a question about the ocean, they'll probably want to know if you're a pisces.

Good jape, got a chuckle out of that.

But it's another stolen word, isn't it? Astronomy is the naming of the stars, Astrology should rightfully be the logical study of the stars, along the lines of the word "Geology". Or it could have gone the other way, I suppose, and I'd have "Planetary Geonomy" on my bookshelf.

Re:I may be wrong, Im not an astrologer

[arminw]

...who's self worth is defined....

  I was not talking about _self_worth, but value assigned not by another human being, but by the God of the universe himself. The nazis assigned zero worth to Jews and gassed them by the millions. Some day, other human beings may have power over you and assign less value to you than a dog and treat you like one or worse. There are also individuals who value themselves low enough to kill themselves. A human being's self-evaluation is a very poor substitute for the independent and only correct evaluation from God. Ultimately, nothing is more important than what God thinks of you, because it determines your eternal destiny.

Re:I may be wrong, Im not an astrologer

[pnewhook]

s proximity to the sun gives it a surface temperature hot enough to melt some metals. Granted, the opposite side of Mercury is also the coldest place in the Solar System

Yes, a stable equilibrium can be a funny thing. Just like its possible to boil water in a paper bag held over an open flame. The water keeps the bag wet enough so it doesn't catch fire, and the flame keeps the bag dry enough so the water doesn't soak though and tear the bag.

Re:I may be wrong, Im not an astrologer

[FromellaSlob]

Not exactly "stolen", the problem is that the mumbo-jumbo had prior claim. People were looking at the stars and making predictions (and I'm sure considered it perfectly scientific) for millenia before the modern scientific method was developed and we actually began to understand what stars are.

Re:I may be wrong, Im not an astrologer

[Anonymous Coward]

I don't see how a solid core should preclude magnetism. If you have a big ball of iron and you magnetize it, it becomes a permanent magnet. Say, like Mercury's core. I have no theories as to why said core would be magnetized, but just the presence of a solid core doesn't preclude the effect, hey, I'd say it may actually solely allow the effect to exist in some cases.

Re:I may be wrong, Im not an astrologer

[TapeCutter]

"nothing is more important than what God thinks of you"

You missed my point, which was that attitude is just sad.

Re:I may be wrong, Im not an astrologer

[spitzak]

I don't know if you are joking, but we certainly knew Mars gravity to within some tiny fraction of a percent. The period and distance of it's orbiting moons can be used to figure it out pretty accurately. You may be thinking of the spaceship that was lost because of metric/english unit confusion?

Re:I may be wrong, Im not an astrologer

[arminw]

so then how would you classify your attitude?

Re:I may be wrong, Im not an astrologer

[PachmanP]

...And Planet X might have a magnetic field due to something else all together.

My guess is Monster Zero

Re:I may be wrong, Im not an astrologer

[fuzzlost]

Well, sort of. Prior to the Age of Reason, astrologers and astronomers where one in the same. It may have something to do with the increasing amount of mathematics involved in studying what we now call astronomy, and those who had more interest in studying the predictive part of the science (astrology) simply did not have the mathematical know-how to continue. Im not sure.

But they were, at one point, one in the same, and during the 16th century different terms began to be used to differentiate the different studies.

And what post would be complete without the trusty Wikipedia quote.

Re:I may be wrong, Im not an astrologer

[Mr Z]

Does that actually work? Seems like there would be a continuum of conditions along the side of the bag, and there would be some point at which "moisture wins" and the bag tears. I can see your point with a paper-bottomed bag though.

Re:I may be wrong, Im not an astrologer

[mister_playboy]

What you learned about Mercury in elementary school was wrong... it is not locked gravitationally with the sun, and the far side is certainly colder than the day side, but not to the extend we were told in grade school.

Mercury has 1.5 days per year... a 3:2 resonance. Early Earth-based observation always saw the same face of Mercury because it is easily observable only during specific parts of its orbit, which can give the appearance that the year and day are of the same length.

Re:I may be wrong, Im not an astrologer

[TapeCutter]

realistic.

Re:I may be wrong, Im not an astrologer

[Tablizer]

Mercury has a magnetic field, which quite surprised planetary scientists when it was first discovered by MAriner 10, as the prevailing theory at the time was that Mercury's small size would have led to its core solidifying by now and stopping the dynamo that generated the field.

Mercury has a larger metal core than normal for its girth. Some speculate that it was involved in some kind of collision early in life that knocked the lighter material away.
   

Re:I may be wrong, Im not an astrologer

[c6gunner]

Provable will show gravity exists, nothing we know can prove how or why, the are not yet provable

Nonsense. Einstein figured it out 60 years ago, and all the evidence since then has shown hm to be correct.

But we don't know how to get it or create it or manipulate it once it is there, at best we can only manipulate other things with it.

Again, nonsense. Judging by the way you phrased that, you probably don't even understand what gravity is. FYI, it's not a thing that we can "get", it's a curvature of space-time. Saying that we don't know how to "get or create gravity" is like saying that we don't know how to get or create time. It's a meaningless phrase, and a ridiculous concept.

Re:I may be wrong, Im not an astrologer

[rusl]

I wonder if the idea that Ganyemede has a liquid iron core is based on the assumption that only liquid iron cores cause magnetic fields?

I would wager money that this is true. All our systems of logic are based on assumptions. Our assumptions about other planets are based on earth (because we know it more).

The examples of these moons certainly is insightful to compare with this radical theory of ocean magnetism. However, it is hardly debunked... proof isn't anecdote. Our theories of the moons of Jupiter will change if our theory of the earth changes. Something like this would be a good excuse for NASA to fire off another probe at these moons - this time with extra magnetism, iron core and water measuring sensors.

Re:I may be wrong, Im not an astrologer

[ultranova]

Well, actually, no there isn't any mathematical evidence to explain gravity. There is mathematical evidence to explain the properties of gravity but that's not what your saying.

There is no such thing as "mathematical evidence". There are theories that describe gravity (such as Newton's law of gravity and Einstein's General Relativity), which have mathematical formulations, and there is physical evidence for said theories.

There are things that mathematics predict (such as frame dragging), but actual evidence for these phenomenon is something you get by testing and measuring.

But we don't know how to get it or create it or manipulate it once it is there, at best we can only manipulate other things with it.

Actually, we do know how to create it or manipulate it. Newton's formulas point out the most obvious way (gather a lot of mass in a single place), and General Relativity describes other ways (such as pressure, force, etc). The theory of Quantum Gravity, once we get that, might reveal still more ways.

The reason why all this knowledge isn't currently used is because getting a gravitational field of significant strength requires absurd amounts of power. Think about it: all the mass in Earth causes such a weak gravity that a housefly can overcome it.

Re:I may be wrong, Im not an astrologer

[taucross]

Great answer. :)

Re:I may be wrong, Im not an astrologer

[Randle_Revar]

>Scientists think they know how our world works,

Well, we are starting to have a pretty good idea.

>but the more answers they get, the more questions they get as well

true, but that does not make the answers we do have less valid or useful

>and so they are not much further ahead than our ancestors.

We aren't, huh? I hope you enjoy the paleolithic hunter-gatherer lifestyle, then.

>Despite all of our technology, we still have not learned to live in peace with one another
That is an issue for Philosophy to tackle or perhaps someday, very advanced psychology/sociology. It has nothing to do with technology, and little to due with science at the level we currently practice.

>Weapons of Mass Destruction which to possibly annihilate the entire human race.
Really, we are a lot more likely to destroy ourselves accidentally via ecological degradation than on purpose with weapons. Either way, that just shows that we do have significant scientific and technical know-how.

Re:I may be wrong, Im not an astrologer

[Locomorto]

Its not true that is not measureable. Indeed some of the first (surprisingly accurate) measurements in 1798: http://en.wikipedia.org/wiki/File:Cavendish-lab.jpg And you are quite right that you weigh differentatly depending on whether you are on a mountain or in a valley, but this different isn't quite insignificant. Thats not to say thats the only way the gravitational field changes though (moving further from the centre of the earth. It's something worth looking up).

Re:I may be wrong, Im not an astrologer

[Muad'Dave]

Consider the word "Consider". Con- is a variant of com- that means 'Together' or 'with' and -sider, meaning 'the stars'. So when you consider something, you're consulting the stars!

Re:I may be wrong, Im not an astrologer

[SleepingWaterBear]

As a physicist you would know that the laws of physics appear to be the same throughout the universe. The binding energies of the carbon atom are just right to make the complex structures necessary for life. There is no other chemistry that we know about that could form any life other than carbon based. Neither scientists nor theologians ever prove anything, but only believe or disbelieve in various facets of their respective discipline.

Of course there's no other chemistry that we know about! Our ability to accurately model complex chemical systems is very limited still, and the vast majority of what we know about chemistry, we know from direct observation of systems in the relatively narrow range of conditions we have here on earth. Maybe in 20 or 30 years we'll have the ability to accurately model the sorts of alternative chemistries that might give rise to different sorts of life, but for the time being, we're limited to what we can see. You're making an argument from lack of imagination, which is what the fine tuning argument is in essence.

Re:I may be wrong, Im not an astrologer

[SleepingWaterBear]

Perhaps he is only playing Devil's Advocate (har har irony), but the point he makes is ridiculous: That the postulation of a creator is exactly as valid as a scientific theory constructed from what we currently understand about the Earth. On one hand, we have a scientist hypothesising that the Earth's magnetic field is created by electrical currents in the oceans (or more traditionally, by the spinning of the Earth's Iron core), and on the other hand, we have a creator who is necessarily more complex than the entire Universe and all it's systems just popping into existence and thinking to himself "Gee, it sure would be nice to have worshipers, maybe I'll make a planet of those." The former builds upon our prior knowledge, the latter defies probability.

The real problem here is the media presenting these poorly substantiated earth science hypotheses as if they were solid science. Then the creationists come along and poke holes in the theories and think they're poking holes in the fabric of science itself. To be fair to the GP, we really don't understand the earth's magnetic field well at all. We shouldn't be arguing that either of these theories is better than the 'God did it' theory, we should be arguing that admitting our own ignorance is better than the 'God did it' theory.

Re:I may be wrong, Im not an astrologer

[smellsofbikes]

>Nobody is saying that the iron itself is magnetic (because then it would be magnetite and not iron anyway).

I'm a little confused by this.
There's lots and lots of iron that's magnetic but isn't magnetite. Magnetite and hematite are both iron oxides; magnetite happens to be magnetic, while hematite isn't. (Well, technically, hematite is antiferromagnetic until it's reasonably hot, at which point it's a type of antiferromagnetic that makes it act magnetic, but that's not something you're ever going to notice unless you're a geek with good equipment.)

The more critical point here is the Curie point, the temperature above which iron is non-ferromagnetic. That's way below the temperature of molten iron, and we assume the core of the planet is molten. As such (if the Curie point isn't pressure-sensitive, which I don't know anything about) we can feel pretty confident that the iron core isn't ferromagnetic, but that it has a magnetic field induced by motion.

Re:I may be wrong, Im not an astrologer

[Will.Woodhull]

Um, no, astrology as I know it has nothing to say one way or the other about this. It is, after all, only a study of the potentials of a any given moment in time, that just happens to use the celestial sphere as a big, accurate, clock.

Frankly, for anything of immediate concern, I find that casting the runes or consulting the tarot deck are better than astrology: you get your answer quicker, and with a lot less fuss and bother about the arithmetic.

TFA does suggest an interesting new-to-us relationship between a manifestation of Air (electromagnetic forces) and Water. Or maybe it is between Water and Fire-- electromagnetism is frequently considered a thing of the Fire element rather than Air.

Oh dear. Now I've confused myself again. How very human of me.

Re:I may be wrong, Im not an astrologer

[Vintermann]

And what do /regular expressions/ have to do with anything?

Re:I may be wrong, Im not an astrologer

[sorak]

My assertion that God just created it that way

You may be the same troll I fed yesterday, when I asked why God would care if we have fingerprints, but your answer makes no sense. The implication that a god just did something, implies that he she or it has no regard for natural processes. I.E., the question has no answer other than "divine power" (or whatever you choose to cause it). So, why would a divine being care if the poles were magnetic? For that matter, why would any of the crap that happened before man matter?

My assertion that God just created it that way, so that we could live upon the earth and worship him is just as valid.

No. Your assertion is like me stating that because Steven Hawking doesn't know everything there is to know about Science, that his opinion is just as valid as that of my 2 year old son. Scientists do not know everything, but they have evidence for the things they claim to know, and that makes their opinion more valid than a creationist viewpoint.

Scientists think they know how our world works, but the more answers they get, the more questions they get as well and so they are not much further ahead than our ancestors.

Do you mean that ones that lost a third of their numbers to the plague, the ones whose average lifespan was 30 years, or the ones who, were they able to see a modern airport, would declare it as either witchcraft, or the work of the Devil?

Yes, the number of questions is staying relatively high, but the relevance and quality of them are improving. Where our ancestors might have said "there is a God. How do we make him fix whatever's wrong with Jeb", a scientist might ask "which of these genes codes for this particular illness", "how does it work", and "how do we fix it". Notice that more unanswered questions does not mean less knowledge.

Despite all of our technology, we still have not learned to live in peace with one another

As for that, well, that is an entirely other argument, but it is also something we cannot undo, and something for which reliance on religion, or anti-intellectuallism will not help, and for which further science cannot hurt.

Re:I may be wrong, Im not an astrologer

[c6gunner]

Incorrect. The evidence since then has shown him not to be incorrect. There is a difference, while it supports his theory and doesn't prove him wrong, it also doesn't prove him right.

That is, of course, bullshit. While your words are accurate in a strictly technical sense, they are completely wrong when it comes to the way we judge knowledge and fact. Using the same vacuous reasoning, you would have to say that there is no evidence proving absolutely any concept ever devised, including simple mathematical equations (eg. "2+2=4").

What you're arguing for is a sort of permanent agnosticism, in which no claim is ever accepted as true. And while this can be a fine thing in science, it's completely unreasonable in day-to-day life.

If we know what it is, then we can manipulate it, we can adjust it, we can do several things with it that means we can get it.

How the hell did you come to that conclusion? We know exactly what the value of "Pi" is, yet we can't manipulate or adjust it in any way. We know what the speed of light in a vacuum is, bet we can't change it in any way. Why in the world would you expect us to be able to modify gravity when we cannot modify any other universal laws or constants?

Re:I may be wrong, Im not an astrologer

[bla]

Astronomy is the naming of the stars, Astrology should rightfully be the logical study of the stars

actually, "astronomy" is the law (or regulating) of the stars. as opposed, for example, to anonymous. "nomos" is law, "onyma" is name (someday, someone will explain to me why the romans decided that the upsilon in greek ought to be transliterated as "y"). so "astronomy" isn't quite as mis-named as it appears.

Re:I may be wrong, Im not an astrologer

[internic]

Scientists know that there are many parameters and constants, including the earth's magnetic field, which have to be exactly right in order to have life as we know it upon the earth. The probability that all of these came into place by any means other than thinking it is absurdly low.

I think that's not really true. In fact, we have no reasonable way to assign it a probability at all (high or low). If you're willing to take the time, I suggest reading this. I do agree with you that Science can not speak on the existence of God; the scientific method is constructed only to look for naturalistic explanations (which is what makes it practically useful), so it's not equipped to answer the question.

Re:I may be wrong, Im not an astrologer

[LunaticTippy]

I used to do this experiment with conical paper drinking cups. The bunsen burner would burn any cup above waterline and boil water pretty reliably. Sometimes a defect in the cup would result in a spill, but it was less than 10% failure rate.

Re:I may be wrong, Im not an astrologer

[gardyloo]

While we do know how gravity behaves and can model it, we can NOT produce it as yet.

Speak for yourself. I'm American. I guarantee that I drag frames.

    How is it that you're expecting us to "create" gravity? Maybe you mean something that's a bit stronger than 10^-40 times the electromagnetic forces. Well, I'm sorry, but the coupling constants don't allow that.

Re:I may be wrong, Im not an astrologer

[gardyloo]

I can't believe that you were able to answer those questions without turning into a blitheringly-enraged idiot (it's what I would have done), but you did. Bravo! (I'm serious.) The poster to whom you were responding needs to do a bit more research before he argues his points.

      We might also mention http://en.wikipedia.org/wiki/Gravity_anomaly .

Re:I may be wrong, Im not an astrologer

[rusl]

I don't really understand moment of inertia, though as a cyclist i am very familiar with angular momentum.

My brief reading of the wikipedia articles suggests that something with a rigid dense core would have a lower moment of inertia because all the mass is concentrated in a smaller area. But if Ganymede has a liquid core wouldn't that contradict the moment of inertia finding? It would support the fluid dynamics creating magnetic fields theory. Anyway, this stuff is all beyond me but I'm sure you are right that the moment of inertia is a very relevant factor that gives clues on what might be inside there.

Seems like there will be lots of computer simulations to test out these theories because the systems seem complicated.

Re:I may be wrong, Im not an astrologer

[Nethead]

"The probability that all of these came into place by any means other than thinking it is absurdly low."

Not when you are working with numbers like this:

http://en.wikipedia.org/wiki/Hubble_deep_field

I'm only important or special to my friends, family and pets (and the corporate overlords that feed upon me.) And if you'll really try to grok infinite, you'll see that there HAS TO BE an infinite number of "you" too. So you're really not "special."

Re:I may be wrong, Im not an astrologer

[mOdQuArK!]

So has anyone ever gathered enough mass in a single place to have a detectable or measurable effect on gravity?

Yes: the Cavendish experiment. I vaguely remember doing a variation of this experiment in a high-school physics class, although in retrospect I doubt the experiment was controlled enough for stuff like electrostatics or air-dynamics to be meaningful. It has been performed properly enough for people to be pretty confident about its experimental results (at least in the Newtonian realm of gravity).

Surely if that was the case, you would weigh different on top of a mountain verses being in the deepest above water Vally.

You do (or at least a standardized weight does), and it has been measured.

There are also experiments based on monitoring the orbit of satellites very closely which use the variations in the satellites' orbits from expected "perfect" orbits to determine how much gravitational influence the Earth is exerting on the satellite at each moment (which can be translated into rough ideas of the density map of the Earth.)

Re:I may be wrong, Im not an astrologer

[mOdQuArK!]

I don't need a fancy invisible god to see that human beings are more valuable to human beings than cockroaches.

Dunno about that - if we were all starving to death, and cockroaches were the only available food, my personal conclusion would be that cockroaches (food) would be more valuable to me than other humans (competition for food). (I suppose in that scenario, other humans would probably become more valuable as food than cockroaches, so maybe my counterexample isn't very good either - as well as being disgusting.)

Re:I may be wrong, Im not an astrologer

[sumdumass]

ts not true that is not measureable. Indeed some of the first (surprisingly accurate) measurements in 1798: http://en.wikipedia.org/wiki/File:Cavendish-lab.jpg

First, I didn't say it wasn't measurable, I said show me where it has been done. You linked to a drawn picture. The difference is that I am not aware of it ever being done. I do know that time seems to increase/decrease relational to the center of an object.

And you are quite right that you weigh differentatly depending on whether you are on a mountain or in a valley, but this different isn't quite insignificant.

And this difference isn't an artifact from the atmospheric air density?

Thats not to say thats the only way the gravitational field changes though (moving further from the centre of the earth. It's something worth looking up).

The interesting part is that orbital and orbital escape velocity requirements are calculated using a constant for gravity. IF gravity changed, then it would be somewhat intuitive that there should be an exponential relationship there of some sort. Then there is the pioneer phenomenon in which both pioneer probes somehow slowed in their distant being gained away from the sun while the speed of their orbits increased. This doesn't seem to fit nicely together.

Re:I may be wrong, Im not an astrologer

[mOdQuArK!]

Science can not speak on the existence of God

To be fair, scientists have just as much qualification to speak on the existence of God as any other human being on the planet: zero, since nobody on the planet has any basis for believing in the existence of God other than they really, really, really want God to exist. It's just that most scientists choose not to make claims about things they don't have any observational evidence for (at least the honest scientists don't).

Re:I may be wrong, Im not an astrologer

[sporkmonger]

More importantly, permanent magnets, when melted, tend to stop being permanent magnets. It then follows that any magnetic field generated by a molten planetary core isn't likely to be caused by the same physical properties as a permanent magnet.

Re:I may be wrong, Im not an astrologer

[demonbug]

That's correct. According to their theory, moons like Europa should have a rather strong magnetosphere.

If you look at the actual paper you will quickly notice that both the slashdot summary and the primary linked article are both inaccurate. They are not suggesting that the oceans create the primary magnetic field of the earth - in fact, in the paper's abstract it clearly states that the field they are discussing is the result of circulation of oceans through the primary magnetic field. So no, according to their theory Europa should not necessarily have a strong magnetic field; they are not claiming that ocean circulation alone is responsible for the earth's (or Europa's) magnetic field.

Re:I may be wrong, Im not an astrologer

[demonbug]

If you actually look at the paper (which is linked in the summary) you will see that it doesn't claim that the earth's magnetic field is generated by ocean currents, as reported by the summary and the linked article. They claim that SOME of the secular variation (changes in orientation and strength of the magnetic field observed at a point through time) is the result of changing circulation of the ocean currents through earth's primary magnetic field. This really isn't groundbreaking, as many (most) paleomagnetists and geomagnetists have considered the idea, but it does show that the effect can be significant. It might also explain some of the correlation between climate change and secular variation that has been observed in numerous records. Instead of the changes observed in the strength and orientation of the magnetic field being the cause (or related to the cause) of climate change, this suggests that they are more likely the indirect result of climate change - climate change affects ocean circulation, which in turn affects the total magnetic field at a given point.

Re:I may be wrong, Im not an astrologer

[arminw]

....Not when you are working with numbers like this:...

  You might want to watch the movie "Privileged Planet" or even better, read the book of that title. You will learn something of the factors that all have to come together on one planet in order to construct life. It turns out, that if you look at the whole picture as we now see it, the Earth is a very special place in the universe.

Re:I may be wrong, Im not an astrologer

[bramblez]

"The assumption is that Jupiter tidal forces have insulated it." Tidal forces stretch a body into an oblong shape. The stretching turns mechanical energy into heat--place a rubber band against your upper lip and stretch it, and you'll feel it getting hotter. The energy comes from the rotation of the body. What about angular momentum, you may ask, isn't that conserved? Yes, it is-- as rotation slows, the orbit gets farther out. Eventually, the bodies will become tidally locked, like how one side of the moon always faces the earth, and the heating stops. In this manor, the earth's rotation is slowing and the moons orbit is becoming farther away. In about 700 million years, there will be no more total solar eclipses!

Re:I may be wrong, Im not an astrologer

[myowntrueself]

Ultimately, nothing is more important than what God thinks of you

God thinks?

News to me...

Re:I may be wrong, Im not an astrologer

[Brian Gordon]

I have to admit at least you're true to your name.

All you have to do is measure the period of Phobos's orbit and its distance from the center of Mars. The mass of Phobos doesn't matter (remember Galileo on the leaning tower of Pisa). We've known the approximate mass of Mars since practically the dawn of astronomy.

Mercury and Venus were a lot tougher since they don't have moons but since modern science we've been able to use lasers and such to get very accurate measurements from gravitational perturbations.

Re:I may be wrong, Im not an astrologer

[sumdumass]

Jesus Christ, don't be a dickhead. I already admitted I was wrong and confused on that. What the fuck are you trying to do, show that your not smart enough to follow a thread to see if whatever you think is so important to say hasn't already been said?

Your calling me true to my name when you're too lazy to click two links and notice that you had nothing constructive to add to the conversation? Now that's funny.

Re:I may be wrong, Im not an astrologer

[Thing 1]

OT re: your sig: "Unless you're British, there is no 'u' in 'Honor'." So that explains what us dumb Americans have been doing these past 8 years!

Re:I may be wrong, Im not an astrologer

[sumdumass]

How the hell did you come to that conclusion? We know exactly what the value of "Pi" is, yet we can't manipulate or adjust it in any way. We know what the speed of light in a vacuum is, bet we can't change it in any way. Why in the world would you expect us to be able to modify gravity when we cannot modify any other universal laws or constants?

You have too much faith in what you don't know. We don't know the value of Pi. It isn't an irrational number we shorten it to be useful to us. Thus we manipulate it. And yes, we have changed the speed of light We are even attempting to use it to our advantage.

Re:I may be wrong, Im not an astrologer

[sumdumass]

That's what I mean, mass was just there and energy was just magically there and somehow, it magically got together and boom. Something was just magically there in order for the big bang to have happened.

Yea, what with nut jobs not understanding that? I mean science has their magic more right then a god ever could right. Oh wait, science doesn't do the it just happened thing, or does it?

Re:I may be wrong, Im not an astrologer

[sumdumass]

It's nice having losers follow you around and mod everything down. It's confirmation that you pissed them off and they have nothing constructive to say or support their position.

Re:I may be wrong, Im not an astrologer

[c6gunner]

We don't know the value of Pi. It isn't an irrational number we shorten it to be useful to us

It IS an irrational number, and we can calculate it's value to any digit you like since it's derived from a formula with specific measurements. The accuracy of the measurements might be a limiting factor, but that's beside the point. Your argument is ridiculous. It's the equivalent of saying that I don't know the width of my desk because I can't measure it down to the subatomic level.

And yes, we have changed the speed of light

No, we haven't. We've slowed down beams of light, but that's irrelevant since it happens naturally in any medium. By your "logic" you could shine a flashlight through a glass of water and claim that you've slowed down light. The speed of light in a vacuum is a constant, which is what I said earlier. The speed of light in various mediums is also a constant, but it's different in each medium.

To say that we can control the speed of light because we can shine it through different mediums is equivalent to saying that we can control gravity because we can assemble matter into lumps which exert their own influence on spacetime. Even if we use your own brand of logic, your initial argument still falls apart.

Now, do you have any specific criticisms about our understanding of gravity, or are you going to keep pulling unrelated arguments out of your ass? Because, if it's the latter, I think I'm done here.

Re:I may be wrong, Im not an astrologer

[internic]

First of all, I'm talking about Science as the body of knowledge obtained by the scientific method, not scientists (who vary in their beliefs about God). Science uses empiricism, it studies testable explanations for repeatable, objectively measurable phenomena. One can accept a view of metaphysics in which the only things that exist are those that can be studied scientifically (I believe this is something close to what's known as logical positivism), or one can have a view of metaphysics that allows for the existence of other things beyond those that can be revealed by science, or one can be a radical skeptic and not even accept the things you can see, touch, and measure as real. All these can be logically self-consistent world views, though they may be mutually incompatible.

Some people claim to have experienced miracles. Others may claim to have a more direct, extra-sensory experience of God(s). None of these are repeatable, objectively measurable things, so they are not admissible according to the scientific method, but I cannot logically rule out that others have had these experiences and that God does, indeed exist. I can adopt an the view of the scientific method that says I accept the simpler view of metaphysics, that these things don't exist (they are imagined, hallucinated, etc.), but this is simply an assumption no more provable than the idea that God does exist. Logic does not necessitate that the only things that exist are those that can be empirically studied. In other words, if you insist that the only things that exist are those that can be empirically tested, you're just being a fundamentalist of a different flavor.

Re:I may be wrong, Im not an astrologer

[sumdumass]

It IS an irrational number, and we can calculate it's value to any digit you like since it's derived from a formula with specific measurements. The accuracy of the measurements might be a limiting factor, but that's beside the point. Your argument is ridiculous. It's the equivalent of saying that I don't know the width of my desk because I can't measure it down to the subatomic level.

Nonsense. That wasn't what is being said at all. It's that we manipulate PI and use it. That is how you brought it up right?

No, we haven't. We've slowed down beams of light, but that's irrelevant since it happens naturally in any medium. By your "logic" you could shine a flashlight through a glass of water and claim that you've slowed down light. The speed of light in a vacuum is a constant, which is what I said earlier. The speed of light in various mediums is also a constant, but it's different in each medium.

The point is that the speed of light is being manipulated for our own purposes. The fact that you can limit it to "in a vacuum" means you got it and used it to your advantage just like with gravity. Except that we have proved we know ways to make light.

Now, do you have any specific criticisms about our understanding of gravity, or are you going to keep pulling unrelated arguments out of your ass? Because, if it's the latter, I think I'm done here.

Actually, the only criticisms I had was the premise of ideas being claimed as fact when they weren't. What we know about gravity, the driving force behind it, is not a proven fact. The facts all relate to properties of it. Sometimes these facts support what we think but cannot prove, but doesn't prove anything.

Re:I may be wrong, Im not an astrologer

[c6gunner]

Nonsense. That wasn't what is being said at all. It's that we manipulate PI and use it.

We don't manipulate it. We can't manipulate constants. That fact is implicit in the definition of the word "constant". We make use of it, sure, just like we make use of gravity.

What we know about gravity, the driving force behind it, is not a proven fact

We don't know why Pi is the value it is, either, but that doesn't mean that we don't know what it's value is, or how we can make use of it.

Now, is it possible that we'll learn more about gravity as our understanding of the universe grows? Sure. In my opinion, it's quite probable. But that doesn't mean that what we know about it now isn't "fact", it just means that our understanding of it is probably incomplete. You can make the same statement regarding just about everything we know on any subject. We don't need to understand every possible aspect of every phenomenon in order to say that we know what it is.

If you're trying to argue that we have a better understanding of the electromagnetic spectrum than we do of gravity, then sure, that much is true. Maybe we're just arguing about definitions.

Re:I may be wrong, Im not an astrologer

[c6gunner]

Actually, ignore that last bit. I wasn't aware of the discrepancy between General Relativity and Quantum Mechanics. And, going back through what you said, apparently you did bring that up, I just skipped over it. Next time, give me something to click :)

Of course, it may turn out that general relativity works fine and that there's a problem with quantum mechanics. That would make me happy since there's still a lot abut quantum mechanics that doesn't make any sense to me :) Still, I guess odds are that Einsteins model was just a useful approximation, and that either quantum mechanics or M-theory will provide a better explanation. I'll have to do some more reading before I can say any more on the subject. Thanks.

Re:I may be wrong, Im not an astrologer

[sumdumass]

We don't manipulate it. We can't manipulate constants. That fact is implicit in the definition of the word "constant". We make use of it, sure, just like we make use of gravity.

So we don't manipulate the speed of light for our own purposed? I thought that was the entire purpose of slowing it down.

We don't know why Pi is the value it is, either, but that doesn't mean that we don't know what it's value is, or how we can make use of it.

Yes we do. Pi is the ratio between a circle's circumference and diameter when measured. Pi is a little of an improper example because it is a property of a circle and we know how to make them.

Now, is it possible that we'll learn more about gravity as our understanding of the universe grows? Sure. In my opinion, it's quite probable. But that doesn't mean that what we know about it now isn't "fact", it just means that our understanding of it is probably incomplete. You can make the same statement regarding just about everything we know on any subject. We don't need to understand every possible aspect of every phenomenon in order to say that we know what it is.

That statement is more to my liking. Except I never said what we know wasn't fact, I said the facts we know doesn't prove it as fact. To understand that, look at it this way. A person awakes from a light sleep and sees a flash of light in a dark room, out of the corner of their eye, they see a person standing by the corner. When they turn the light on, the person is gone. The facts are there was a flicker of light, most probably a lightning strike or perhaps a car making corner down the road with a maladjusted headlight. The person in the room is a fact and that they think they saw someone else with them is a fact. It could have been an angel appearing and disappearing, a ghost, a burglar or some other intruder, or a coat rack that resembles another person. Now suppose other evidence in the area is that someone is breaking into houses and kidnapping people or is watching them sleep. There is no proof that anyone else was in the room, but there is enough facts that someone can believe there was whether they are right or wrong in that belief. They can even convince others that there was someone else in the room too but that doesn't mean it wasn't just an illusion from tree branches outside the window casting a shadow onto the coat rack when the flash of light happened. Gravity is much in the same way, we know it is there, have convinced ourselves of why or how it is there with competing theories and attempts to explain the quantum differences, but we don't have any more proof then that of the person who thinks they saw someone in the room in a brief flash of light. It is probable that we are right, it is probable that if we are wrong, we will be right, it is probable that were aren't off by much. But we are talking probables.

If you're trying to argue that we have a better understanding of the electromagnetic spectrum than we do of gravity, then sure, that much is true. Maybe we're just arguing about definitions.

It could be the definitions. The evidence and theories or evidence supporting theories for gravity show a good bit of understanding but they are incomplete and not proven as fact. Now fact is a direct observation that we can test for and repeat in science where fact outside of science means undisputed (indisputable) evidence. She walked across the room is a fact in both. The magician made the elephant appear out of nowhere is a fact that can only stand with the lack of other evidence like the secrets of the trick. Outside of science, that is a fact as perceived by the audience, inside science, it just means more is happening like smoke and mirrors.

Re:I may be wrong, Im not an astrologer

[edittard]

Er, you wrote "tenets".

Not "tenants". Not "tennants". Not "lietenants". We don't take kindly to high-fallutin' speakin-proper book-learnt college boys round these here parts.

Re:I may be wrong, Im not an astrologer

[Bigjeff5]

the real problem with the molten iron core theory, happens to be, as any good metallurgist

Actually, he isn't a very good metallurgist if he doesn't also tell you that rotating currents of a conducting but non-magnetic substance will produce a magnetic field.

You're saying a molten iron core is implausible because it becomes non-magnetic at those temperatures in defense of a theory that says the conductive nature of the Ocean combined with ocean currents create magnetic fields.

I've got a bit of news for you, molten iron is still conductive and when it spins it creates a neat magnetic field.

The theory of molten metal creating a magnetic field was proven with molten lead in a large sphere - the scientists had a sphere that was designed to hold and contain molten lead (I think, much lower melting point than iron though whatever they used). They read no magnetic field before spinning, then spun the sphere and suddenly there was a neat magnetic field similar to the earth's. I don't remember the documentary, but I wathed it on the Discovery Channel, it was cool.

This doesn't "prove" that a molten iron core is causing the magnetic field, but it proves the concept. I could see oceanic currents influencing the field, but I think a molten core is much more likely to produce the substantial field we have. I.e. I could see oceanic currents being responsible for moving the magnetic poles, but not creating them in the first place.

Contrast that with Mars, which has no magnetic field and also has a solid, cool core (it also has no oceans though).

Re:I may be wrong, Im not an astrologer

[Jarik C-Bol]

i never said i was defending the stupid water theory.

Re:But this would mean?!?!?!?!?

[Gravedigger3]

What was it before?

Uh, right.

[pclminion]

Yeah, that makes a whole hell of a lot of sense. Why not invent some brand new, goofy theory that applies only to the Earth and not to any of the other celestial bodies that we know have magnetic fields which DON'T have oceans? Has somebody never heard of Occam's Razor? Instead of one theory which works to explain all magnetic fields on all celestial bodies why not invent something stupid for no good reason?

Re:Uh, right.

[MrMista_B]

Because the other theory hasn't been tested, and might be wrong.

Ignoring possible alternative theories, especially for unknowns, is no different from adhering to dogma on pure faith alone, and damages scientific inquiry.

Re:Uh, right.

[interkin3tic]

Why not invent some brand new, goofy theory that applies only to the Earth and not to any of the other celestial bodies that we know have magnetic fields which DON'T have oceans? Has somebody never heard of Occam's Razor?

Better question: Is somebody misinterpreting Occam's Razor? The answer is "yes: pclminion."

Re: Uh, right.

[sakdoctor]

Occam's Razor was the razor to own. Then the other guy came out with a three-blade razor. Were we scared? Hell, no. Because we hit back with a little thing called the Occam's Razor Turbo. That's three blades and an aloe strip. For moisture. But you know what happened next? Shut up, I'm telling you what happenedâ"the bastards went to four blades. Now we're standing around with our cocks in our hands, selling three blades and a strip. Moisture or no, suddenly we're the chumps. Well, fuck it. We're going to five blades.

Re:Uh, right.

[pclminion]

Because the other theory hasn't been tested, and might be wrong.

The point is that the chances that each celestial body's magnetic field is due to a unique generator are... Well, let's say that that is not what we typical see in scientific history. Similar effects are generated by similar causes, especially at planetary scales.

(I see that I've been misled by the summary, as usual. Yes, I should RTFA. But the editors should fucking WTFS in a manner resembling responsible journalism. Could currents in the oceans modulate the magnetic field? Worth investigation, I think.)

Re: Uh, right.

[interkin3tic]

I like it, occam's razor turbo:

"Of several acceptable explanations for a phenomenon, the simplest is preferable even when there's good evidence to suggest a more complex explanation and no evidence to suggest the simplest. Furthermore, that evidence is automatically invalidated by the first guy to yell out 'Occam's razor,' especially when the guy makes no attempt to explain himself."

Re:Uh, right.

[physicsphairy]

According to the article, there is no direct evidence for the metal currents which allegedly induce the magnetic field. They are inferred on basis of the existence of the field. Venus doesn't have a magnetic field--so we decide it doesn't have a molten iron core. The only reason the 'present theory' is so simple and explanatory is because we arbitrarily decide on the planets' internals are such that our theory is always guaranteed to fit.

Your generalization is also a bit off, as plenty (probably most) of the large celestial objects have magnetic fields but lack iron cores. The sun certainly lack an iron core. We assume Jupiter's magnetic field is supplied by metallic hydrogen, but it could just as easily support it by electrical currents.

The magnetic fields are actually quite complex and Occam's razor doesn't mean assuming everything is a perfect sphere, as the classic joke goes. If the oceanic theory successfully explains secular variation then Occam's razor may be more likely to back the ocean theory than the dynamo theory.

Re:Uh, right.

[im_thatoneguy]

I am neither a geophysicist nor am I an oceonographer nor am I any sort of natural scientist. BUT there is a place for this sort of theory. You're essentially advocating the watchmaker theory.

"Since all sophisticated machine whose origins we have observed are by an intelligent creator all sophisticated machines are therefore created through intelligent design."

The alternate scientific theory is that "While intelligent designers do create things (including potentially life) we think the more likely explanation free of unnecessary supposition is natural Evolution."

Occam's razor in this case is not necessary because as TFA states we don't necessarily have proof of a molten iron dynamo. Therefore there could be multiple causes of magnetospheres and on earth our cause might not be the same as on other planets.

I wouldn't give this theory as strong of a likelihood but it's certainly not an superfluous claim subject to Occam's razor just an alternate one.

Re:Uh, right.

[contrapunctus]

I propose the aether is responsible.

Re: Uh, right.

[doublebackslash]

^_^ That was a good onion article, that one was.
http://www.theonion.com/content/node/33930

By the by, when did the onion open up their archives? I recall them shuffling articles out of their free page very quickly.

Re:Uh, right.

[MrMista_B]

True, true, and I admit I was also misled by the misleading, inflammitory summary. Such is Slashdot these days, I suppose.

Re:Uh, right.

[Anonymous Coward]

Are you suggesting we remove all water to test this hypothesis?

Re:Uh, right.

[plover]

I propose the aether is responsible.

I blame the thetans.

Re:Uh, right.

[jcr]

we arbitrarily decide on the planets' internals

No, we constantly refine our model of the earth's internal structure by seismic studies, as well as studying surface, volcanic, and deep-ocean rocks.

-jcr

Re:Uh, right.

[Asic Eng]

Yeah global warming zealots like McCain, Bush, oil executives like the chairman of Shell ... damn hippies.

Obviously any currently accepted scientific theory could be wrong, inaccurate or incomplete. There is always a chance for a scientist to spot a flaw, publish about it and make a name for himself. However the theories behind climate change have very broad and scientifically sound support, they are very much in the mainstream. That doesn't mean they must be correct, but it's intelectually dishonest to pretend these views were only held by a fringe group.

Re:Uh, right.

[Jesus_666]

The sun certainly lack an iron core.

Hence the magnetic ocean theory.

...Wait.

Re:Uh, right.

[demonbug]

To be fair, the paper doesn't make the claim that the article and summary say it makes. The paper only claims that some of the secular variation observed in paleomagnetic and geomagnetic data may be the result of variations in the flow of ocean currents through the "primary" magnetic field. There is no claim that the ocean currents are responsible for this primary field. As seems all to common, the slashdot summary is wildly inaccurate - although in this case there is an excuse (sort of), as the linked article is also wildly inaccurate.

New possibilities in terraforming?

[Kleebner]

Fascinating! If true, I wonder how it could effect theories on terraforming. If we got enough open and moving water on Mars could it then develop the field needed to block solar radiation and trap an atmosphere?

Re:New possibilities in terraforming?

[jd]

If it's true, then think more in terms of terror forming. The Earth's ocean currents are showing some dramatic changes as a result of global warming.

Re:New possibilities in terraforming?

[DerekLyons]

Which is an interesting question - because it's currently believed that loss of the magnetic field cause the loss of atmosphere and the subsequent loss of water on Mars.
 
Failing to explain Mars represents a major hole in this theory.
 
Failing to explain why the Earth's magnetic fields are more-or-less symmetrical, which the core is and the oceans aren't, is another major problem.

Re:New possibilities in terraforming?

[mister_playboy]

The combination of gravitational and magnetic fields required to hold liquids and an atmosphere intact is quite complicated. The two terrestrial bodies in the Solar System with thicker atmospheres than Earth (Venus and Titan) lack any real magnetic field and have weaker gravity than Earth. (0.904 g for Venus and 0.14 g for Titan) Titan has 1.5 times the Earth's surface pressure, while the pressure on Venus is an incredible 92 times greater. Venus is far hotter than Earth, while Titan is far colder... many factors must be involved.

Mars (at 0.376 g) would be able to maintain quite a bit more of an atmosphere if it were protected from the solar wind. Surface pressure is less than 1% of Earth's.

Summary wrong: Oceans only small variations

[Anonymous Coward]

The Slashdot summary is totally wrong.

From the abstract of the paper: "I propose a different mechanism of secular variation: ocean water [...] as it flows through the Earth's main field may [...] manifest itself globally as secular variation."

Meaning: There is a major magnetic field that comes from the molten core. However, certain variations that are as yet unexplained may not result from core phenomena, but from the ocean currents.

I find this much more believable than the swill in the slashdot summary.

Re:Summary wrong: Oceans only small variations

[Gravedigger3]

Its not totally wrong.

FTA: "While Ryskinâ(TM)s research looks only at long-term changes in the Earthâ(TM)s magnetic field, he points out that, âoeIf secular variation is caused by the ocean flow, the entire concept of the dynamo operating in the Earthâ(TM)s core is called into question: there exists no other evidence of hydrodynamic flow in the core.â"

He does go so far to say that there is no examinable proof of a liquid core and that we could have been wrong all these years.

It doesn't seem too far fetched for me, but I'll leave the proof to the geomagnetism community.

Re:Summary wrong: Oceans only small variations

[Anonymous Coward]

Well, but saying that a dynamo process in the core may not be happening is not the same as claiming that the oceans are doing it. The paper does not actually say what might replace the dynamo model, but obviously the oceans cannot generate a primary field. They can manage the secular variations by moving in the main field, but those are a factor of 1000 weaker than the persistent field.

Re:Summary wrong: Oceans only small variations

[CheshireCatCO]

He says,

If secular variation is caused by the ocean flow, the entire concept of the dynamo operating in the Earthâ(TM)s core is called into question: there exists no other evidence of hydrodynamic flow in the core.

--From the article

Er, dude, no. We are pretty certain that the outer core is a liquid from seismic wave data. "So what?" you say, "Couldn't the core not be flowing?" Perhaps, but our understanding of how heat moves in a fluid is pretty good. And we know that at some point, in order to move the heat out, the fluid has to convect (as the dynamo model requires). So while we haven't directly measured the flow of fluid in the core, arguing that it isn't happening requires at least some explanation of the lack of convection we have every reason to expect.

That said, let's look at the notion that the oceans are responsible. This ought to be measurable if it's worth talking about. We can get close enough to the oceans that we should easily be able to measure variations in the local field due to the oceans. Heck, tides and changes in circulation patterns ought to manifest temporal variations that we could measure. No, I don't know that anyone has done these measurements, I would be a bit surprised if no one had. (In fact, if no one has, I ask: why hasn't the author?)

Also, I'm skeptical by comparison to Europa. That body is in a changing magnetic field that is much more powerful than Earth's (and which changes much more rapidly, every 11 hrs). The ocean required to produce the induced field has something like 3 times (from memory) the salinity of our ocean and only produces a response of ~100 nT. (Our magnetic field is around 50 mT.) I'm... skeptical.

Re:Summary wrong: Oceans only small variations

[syousef]

I find this much more believable than the swill in the slashdot summary.

Take a look at who submitted it. PEBKAC.

Re:Summary wrong: Oceans only small variations

[RobVB]

A few interesting links with more info about these subjects:

http://gsc.nrcan.gc.ca/geomag/field/sec_e.php (about secular variation)

http://en.wikipedia.org/wiki/Magnetic_declination (about magnetic declination, obviously)

Long story short, magnetic declination is the difference between the geographical North Pole and the apparent magnetic North Pole at any one place on earth. The secular variation they're talking about is the gradual change in that magnetic declination, or the apparent movement of the Earth's magnetic North Pole. Secular variation is usually between 0 and 15 arcminutes per year - specific example: a nautical chart of the Thames Estuary from 2008 lists a yearly secular variation of 8' (arcminutes) Eastward.

Re:Summary wrong: Oceans only small variations

[mapkinase]

"The Slashdot summary is totally wrong." that's kdawson for you

Re:Summary wrong: Oceans only small variations

[DerekLyons]

He does go so far to say that there is no examinable proof of a liquid core and that we could have been wrong all these years.

While there is no proof you can put your finger on - rejecting a hypothesis supported by other evidence without providing a replacement for that hypothesis is pretty dodgy science.

Re:Summary wrong: Oceans only small variations

[Gerzel]

Well we DO know that there is liquid iron and rock in the Earth's interior. Volcanos spew the stuff out all the time.

Now we also know from evidence that the deeper you go, the hotter it gets, miners have encountered this quite a lot.

Now we also know that hot things tend to melt and with our other evidence we have presence of molten minerals(with quite a large amount of iron in many cases) coming up from deeper in the earth than we can study, as well as a lot of evidence that the heat is spread over the entire world and not just near volcanoes.

Yes there could be a solid ball at the center but we can be fairly sure that between that unknown ball and the crust there is a layer of molten rock, which more than likely contains a high concentration of iron.

Re:Summary wrong: Oceans only small variations

[Tokerat]

I wonder when we'll stop being modded as Troll or Flamebait for pointing this out; this is the 10th or 11th bad summary I've seen submitted by you-know-who in as many days. I've been here for 10 years, and said editor is REALLY pretty bad.

Notice that the quote from the paper sums things up rather clearly - it's the editorial *addition*.

Re:Summary wrong: Oceans only small variations

[CheshireCatCO]

Well we DO know that there is liquid iron and rock in the Earth's interior. Volcanos spew the stuff out all the time.

To be fair, that stuff coming out of volcanoes isn't from the core. At the deepest, you might be seeing the mantle. (I can't recall how deep material comes from.)

And the inner core is solid, for the record. The outer core? Liquid.

Re:Summary wrong: Oceans only small variations

[sFurbo]

Well, magnetic fields and seismic data. It was discovered that P-waves sould pass through the core, while S-waves couldn't, which could only be explained by a liquid outer core.

Re:Summary wrong: Oceans only small variations

[DrLudicrous]

not 50mT. 50 MICROtesla. like .05 mT. or 5*10^-5 tesla.

Re:Summary wrong: Oceans only small variations

[CheshireCatCO]

Gah, correct. I mean microT but forgot to try to find the character code for mu. My fault for being lazy/forgetful.

The point stands, however.

Simply solved

[Creepy Crawler]

Well, relativity simply solved.

All we need to do is find an object that has a magnetosphere and no aqueous sea.

How about the Sun?

Re:Simply solved

[Lupulack]

The sun doesn't appear to have much in the way of flowing iron at its core either. Does that mean that it can't have a magnetic field?

Essentially the theory stands at : flows of conductive fluid ( salt water, iron, plasma ) can generate magnetic fields. We have no evidence that there is flowing iron in the earth's core, but we have rather a lot of flowing salt water. Hmmm...

Re:Simply solved

[CheshireCatCO]

Better example: Mercury.

Re:Simply solved

[Lupulack]

I didn't say there was no iron at the core of the sun, only that there wasn't a great deal of it, at least in comparison.

And to quote the article linked, ''If secular variation is caused by the ocean flow, the entire concept of the dynamo operating in the Earth's core is called into question: there exists no other evidence of hydrodynamic flow in the core.''

So the only evidence of flowing iron at the earth's core causing the earth's magnetic field is ... the existence of the earth's magnetic field itself. That's a bit circular, isn't it?

Re:Simply solved

[Progman3K]

The sun has a sort of liquid... Plasma...
Of course the summary for the article is wrong, so we can just make up stuff if we want to.

Re:Simply solved

[cyn1c77]

I didn't say there was no iron at the core of the sun, only that there wasn't a great deal of it, at least in comparison.

And to quote the article linked, ''If secular variation is caused by the ocean flow, the entire concept of the dynamo operating in the Earth's core is called into question: there exists no other evidence of hydrodynamic flow in the core.''

So the only evidence of flowing iron at the earth's core causing the earth's magnetic field is ... the existence of the earth's magnetic field itself. That's a bit circular, isn't it?

The author does not argue that the oceans cause the Earth's entire magnetic field, he only argues that they cause smaller temporal variations in the magnetic field. He says "The current consensus is that the main field is generated by the hydromagnetic dynamo in the Earth's fluid outer core." He questions this consensus at the end because (1) he has presented an alternate mechanism for small variations in the field strength and (2) he clearly disagrees with the accepted theory. But be can't contradict it because his work does not provide an alternate mechanism for the generation of the full field.

It isn't circular logic: The earth has a magnetic field. The oceans by themselves are not able to generate the Earth's full magnetic field. We know there is liquid iron at the earth's outer core. Flowing iron is the simplest concept capable of causing the magnetic field that we measure based on available knowledge. Nothing else proposed to date is as likely. So we conclude that there is flowing iron at the Earth's core.

Mod me down all you want for quoting the facts. But until someone can propose and supply supporting data for a different method of generating the entire Earth's magnetic field, accepted geological theory isn't going to change.

Re:But this would mean?!?!?!?!?

[interkin3tic]

What was it before?

A coffee coaster.

Re:But this would mean?!?!?!?!?

[larry bagina]

The magnetic field is believed to prevent solar wind from eroding water and oxygen. If ocean water creates a magnetic field that prevents water from eroding .... that's a serious chicken/egg problem. FWIW, Mars used to have water and may have at one point had a stronger magnetic field than the Earth. It currently has a weak magnetic field and negligible water. Mars doesn't have a large moon to create tides, either.

Comment removed

[account_deleted]

Comment removed based on user account deletion

Headline is a Lie

[MrMista_B]

Read above.

Ocean currents are /NOT/ being proposed as a cause of the magnetic field.

The headline is a lie.

Just last night...

[Anachragnome]

Just last night there was an interesting show on television that focused on the subject of magnetic fields associated with planets.

There was an experiment covered in the show that was essentially a large, hollow orb filled with liquid sodium (a substitute for the iron at Earth's outer core. It is impossible to reproduce the pressure and heat of our Earth's guts in such a small scale experiment) which was then spun at a comparatively equal rate to that of Earth. The orb began producing strong magnetic fields.

I somehow doubt that if the same experiment were to be reproduced solely with a thin layer of salt water on the surface (and no sodium inside) that it would produce such strong magnetic fields. That being said, while the thought of Earth's magnetic field being produced solely by the water on the surface is interesting, personally I think it is more then likely a combination of the two factors rather then one alone that produces our protective magnetic field.

In addition, I wonder if the flux in ocean water levels, historically speaking, coincides with the strength and direction of past magnetic fields as recorded in ancient lava flows. If so, this would seem to back up the theory proposed in the article.

Re:Just last night...

[db32]

[Citation Needed]

Seriously...please do. I was aware of the whole molten sodium ball thing because I remember that spinning 13 tons of molten sodium could be a REALLY bad idea. However, the last I saw of it they were still preparing and had not actually done anything yet.

Also...TFA isn't saying the field comes from water, it says variations in the field come from water passing through the main field. In typical /. fashion the summary is nonsensical crap.

Re:Just last night...

[dissy]

I was aware of the whole molten sodium ball thing because I remember that spinning 13 tons of molten sodium could be a REALLY bad idea. However, the last I saw of it they were still preparing and had not actually done anything yet.

The last I've heard on that very subject was from a NOVA documentary called Magnetic Storm, which aired in November 2003.
In that documentary, they were just preparing for the experiment with the molten sodium, but did not start.
Which sounds like about the same state you have last heard about as well.

I would have hoped in 6 years time they would have been able to start their experiment but I can not find any updates on their work.
I too would be curious to know what resulted from it.

In case you are interested:
http://www.pbs.org/wgbh/nova/magnetic/about.html

Re:Just last night...

[publiclurker]

The show is called inside planet earth and was on the Discovery Chanel last night. They only spent about 3-4 minutes on the people experiment.

Re:Just last night...

[Anachragnome]

Thank you. That would be the show.

Re:Just last night...

[mister_playboy]

I also saw this. They were focusing on an area in the South Atlantic where the magnetic field is weakening. This seems to be indicative of a coming reversal of the Earth's magnetic field. The actual reversal probably occurs over at least 1000 years, so we won't get to experience it.

The field reversal being a common reoccuring event has evidence everywhere you look, from the ocean floor to the rocks near your house. Most of us accept the fact that dinosaurs existed, and this phenomenon has left way more physical evidence laying about than they ever did.

The oceans of Earth seem large to a human being, but they are quite tiny compared to the volume of the inner and outer core of the Earth... the idea that they "create" the magnetic field is ridiculous. Do they have some local effect on it? Certainly.

It doesn't say ocean currents cause the field

[John Hasler]

The paper does not say that ocean currents cause the magnetic field. It hypothesizes that ocean currents cause secular variations in the magnetic field.

Re:It doesn't say ocean currents cause the field

[bigpat]

However the paper concludes with this conjecture: "If the secular variation is caused by the ocean
flow, the entire concept of the dynamo operating in the Earthâ(TM)s core is called into question: there
exists no other evidence of hydrodynamic flow in the core." So while the paper doesn't say it, the author seems to entertain the possibility that currents my be solely responsible for the magnetic field.

That's not it at all. At least not in the part you quote or from what I have seen so far. The author is talking about the shorter term variations of the field not the totality of the magnetic field.

If the oceans can explain those variations, then the models for the earth's interior need to be updated to discount for that effect.

Re:It doesn't say ocean currents cause the field

[fxj]

OMG you RTFA!!!

yeah you are right! but that would not be sensational enough for being news for nerds.

Re:It doesn't say ocean currents cause the field

[John Hasler]

> If the oceans can explain those variations, then the models for the earth's interior
> need to be updated to discount for that effect.

In fact it should simplify them.

Now, here is some wild speculation:

1) Could the magnetic field alter the currents? Afer all, they constitute a a conductor
      moving in a magnetic field and are therefor going to be subject to some forces.

2) Might it be possible to measure the induced voltages? The Hall effect voltages?

Testing, testing...

[hyades1]

We might have proof of this in the foreseeable future. If we keep warming up the planet, it's quite possible that one or more major ocean currents will start behaving differently. If that happens and we see a change in the magnetic field, that would provide a strong hint that the two are connected in some way.

Re:Testing, testing...

[Gothmolly]

Except NASA has just published data which suggest that the Solar cycle strongly influences the Earth's climate, more so than AGW. So go back to being irrelevant, Al Gore.

Re:Testing, testing...

[hyades1]

You're out of date. Please check your facts before you run your mouth on something you clearly know nothing about.

Fucking idiot!

http://www.sciencedaily.com/releases/2009/05/090511122425.htm

A big fish story is circulating into a vortex

[itsybitsy]

Wow, that's quite the fish story. Pretty interesting hypothesis though it needs solid, er, liquid evidence to back it up... otherwise it's flowing into the dust bin, er, drain of science history as a pretty darn cool and silly theory that didn't make it.

Well actually he's saying that there is a "main field" and that the ocean currents are a modification or additional field. Cool. Cutting edge science can be fun. It's where cross currents of ideas and beliefs mix until evidence eventually coalesces with a vortex pulling everyone to the indisputable conclusions - if you're lucky and on course of course.

I wonder if this hypothesis might explain the "magnetic anomalies" in the oceans around the world that are constantly changing? I'd love to see a three dimensional simulation of the raw data collected by the magnetic sensing satellites and the gravity satellites correlated together with ocean current movements.

Does this theory spin the other way in the southern hemisphere?

Pseudoscientists attend!

[rlseaman]

Note how this dishes the favorite argument of pseudoscientists, who always (always, always) claim that the scientific "establishment" refuses to hear evidence that conflicts with accepted wisdom. Rather - to the extent that such an establishment can be said to actually exist - science will entertain any sort of extreme argument, as long as it is cogently - and entertainingly - presented. To overturn competing theories extreme arguments ultimately demand extreme evidence, however.

Re:Pseudoscientists attend!

[osu-neko]

Science has always reserved its greatest accolades for those who prove what came before to be wrong, and every scientist in the world knows the best way to become famous is to prove everyone else wrong. Nevertheless, pseudo-scientists always argue that scientists have some vested interest in preserving the current order (and thus dooming their careers into obscurity when they could have become famous Nobel prize winners). This argument has never made any sense, but that doesn't stop them from making it. So, one more example won't make any difference to them -- people who advocate a bad argument that runs counter to evidence are not dissuaded by more evidence.

Re:Pseudoscientists attend!

[smellsofbikes]

>Nevertheless, pseudo-scientists always argue that scientists have some vested interest in preserving the current order (and thus dooming their careers into obscurity when they could have become famous Nobel prize winners). This argument has never made any sense, but that doesn't stop them from making it.

It makes perfect sense from the perspective of history: it's what societies and churches have always done in the past. The idea that science works differently than most of recorded history, that it's not only open to change and contradiction but that's actually what drives it, isn't clear to most people -- including many scientists. Look at how roundly and thoroughly Alfred Wegener was attacked when he first proposed plate tectonics: he died in a snowstorm in the Arctic because he couldn't find a job anywhere else.

Re:Pseudoscientists attend!

[rlseaman]

Look at how roundly and thoroughly Alfred Wegener was attacked when he first proposed plate tectonics

I can't comment on Wegener's personal story, although I may see about tracking down a biography. Plate tectonics, however, is a perfect example of an extreme (but true) scientific inference that required extreme evidence, ie., evidence the gathering of which required not only submarines but sensitive magnetometers unavailable to Wegener: http://pubs.usgs.gov/gip/dynamic/developing.html.

Somehow the creationists still manage to interpret this as evidence of Noah's flood: http://creationwiki.org/Geomagnetic_reversal. This slavish adherence to a single preselected position is precisely why creationism is an "ism", not "creation science".

Winds

[4D6963]

Ocean currents? Here's an even better idea : winds! I know it's true because when I throw a fridge magnet in the wind it goes in the same direction. So next time you want to know in what direction the wind is going, just look at a magnetic compass!

Another reason to dig deep...

[RobVB]

... and I mean that literally. I'm a big fan of space research, but maybe we should also be working on an expedition (or Journey, if you will) to the Centre of the Earth. Or at least find a way to take samples and readings down there. Humanity has never dug deeper than 12,262 meters(*), and although I see the obvious problems in digging for lava, I'm convinced it would yield interesting results.

(*) This number was taken from the following article, about a Russian digging experiment: http://www.damninteresting.com/?p=567

And I'll just post this here too: http://en.wikipedia.org/wiki/Integrated_Ocean_Drilling_Program

Re:Another reason to dig deep...

[Culture20]

It's not going to happen. Did you know that the mantle (what turns into magma/lava at lower pressures) is solid? So any drilling into solid mantle will cause explosive decompression of hot rock turning it into magma. And that's a long way before you get to the outer core.

Re:Another reason to dig deep...

[RobVB]

I didn't say it would be easy.

Language matters

[Mr_Chang]

"The currently predominant theory ...of Earth's magnetic field"

To be certain, there are NO 'theories' for Earth's magnetism, only a variety of HYPOTHESIS'S.

Once again the term theory is being misused for HYPOTHESIS. It is a great disservice to science and scientists to not understand the definition and implications for both terms.

A worker whose research achieves the level of Theory is among the 'Nobel class' of scientists. Therefore the term should be used properly and with some reverence.

So before we go any further, would someone venture to post the scientific definitions and usage for these two terms, hypothesis and Theory.

Thanx

Re:Language matters

[ceoyoyo]

A worker whose research achieves the level of Theory is among the 'Nobel class' of scientists.

Nope. There are big theories and little theories, (probably) right theories and wrong theories. The dividing line between a theory and a hypothesis is very often blurred, fuzzy and not at all agreed upon.

Generally a hypothesis is considered to be a fairly simple, smaller scale idea that is individually testable. An simple prediction. A theory, on the other hand, is usually a large scale set of ideas that has some explanatory power and can be used to make multiple predictions.

The idea that there is an attractive force between all bits of matter is the theory of gravity. The idea that an apple will fall to the ground when released from an apple tree is a hypothesis.

The idea that salt water makes a significant contribution to the magnetic field is a bit trickier. I'd tend to call it a hypothesis, but I certainly wouldn't say that someone who called it a theory was doing a disservice to science or scientists. I would tend to put a collection of ideas that describe the origin of planetary magnetic fields reasonably into the theory category.

A theory is NOT a confirmed hypothesis, and a hypothesis is NOT an unconfirmed theory. There are lots of definitions floating around the web that stumble over themselves and do backflips to try to indicate that (about.com makes up the category "hypothetical theory" to describe M-theory). A good counter example is string theory: definitely NOT confirmed but with a breadth that makes it really not a hypothesis. Another example is Einstein's theory of relativity, back at the beginning of last century. It had not been confirmed. There was a lot of opposition to this theory that proposed to overturn Newton. But, the theory made a bunch of predictions that generated hypotheses that could be tested. Maybe the most famous of which was the hypothesis "when a star's light travels close to a large body such as the sun on it's way to our telescope, it will be deflected by gravity, making the star appear to change position." This hypothesis was tested, and found to be true, lending support to the theory of relativity.

Another example is quantum mechanics. Einstein and many of his colleagues really disliked the new theory and thought it could not possibly be correct. Yet hypotheses designed to test the theory continued to support it.

Joke or not,,, I was trying to think of other mean

[way2trivial]

the general argument here is that other planets lacking oceans also have magnetic fields-- so that ain't right..

so I'm thinking, what do all solar bodies have in common that could be another means to that end

solar wind? the flow of all the radiation from the sun, wrapping around the planet, and blowing on? happens to all objects in the system??

Especially when we keep crashing planes into them

[atmurray]

Too soon?

Because someone has to respond to trolls

[Anonymous Coward]

Funny words from someone who used rather massive ad hominem by trying to label people disagreeing with him as zealots.

Consensus is used as an argument because not all of us can be climate scientists. There is large consensus among them that global warming is happening and caused by men. Not all agree to that. Name any theory and you have people who disagree with it. Hell, there is even a flat earth society. But big majority of the expert who know about the subject and have studied it their whole lives believe so.

Most of the people who argue about it in the internet aren't climate scientists. They've read a few stories which have quoted some climate scientists who disagree with the mainstream and then begin arguing. To them I can always answer "Hey, I am not an expert in the field. And honestly, most likely you aren't either. When your arguments are good enough that they manage to sway opinions of the expert, then you can come back to me. Otherwise I have all the reason to assume that there is some flaw in them."

All of us who aren't experts in every field of science have to do that about some subjects. Trust the scientific method and through that, the experts who employ it.

Re:Because someone has to respond to trolls

[arminw]

...There is large consensus among them...

  Of course, just because there is a large consensus, that has to be the truth. After all has that not been the case throughout history? The earth's average temperature is a slight upward trend at the present time. A political group with an agenda has picked this up and is trying to use it for their own purposes. The temperature has been going up and down for ages and will continue to do so or as long as man lives upon the earth.

Re:Because someone has to respond to trolls

[Jesus_666]

There is large consensus among them that global warming is happening and caused by men.

That's not consensus among climate scientists; that's consensus among feminists.

Re:But this would mean?!?!?!?!?

[Anonymous Coward]

I wasn't aware water really responded much to solar radiation. Aren't some spaceship plans built with water used as shielding against solar flares? Water is pretty darn stable. There's lots of water ice in comets, and Mars probably does have lots of water, it's just ice.

Didn't this guy prove it was the molten inards?

[BradyB]

This link to an article on NPR, http://www.npr.org/templates/story/story.php?storyId=90947943, was also in a short show on the Science Channel about magnetic fields. So, I think that the reader should not state that there is no evidence that the molten inards of the Earth are not the probable cause of our magnetosphere.

Re:What happens when Ocean current patterns change

[osu-neko]

While I have no expertise in this area ... Are ocean current patterns really as static as the Earth's magnetic field?

Yes. Neither are static, both change continuously, but both are relatively slowly changing phenomena.

I'd think that there would be more fluctuations/variations in the Earth's magnetic field if it depended on the waterbodies.

On geological timescales, it would change dramatically. Which, we know, it does.

Wouldn't this also require compasses / magentic fields being disrupted when there are earthquakes/tsunamis or major storms?

No, since large-scale ocean currents are not noticeably affected by these things.

Re:Bermuda triangle?

[osu-neko]

Could this be an explanation for the Bermuda triangle?

I don't think so. There's no reason to expect that the Earth's magnetic field, whether influenced by ocean currents or not, has any impact on the tendency for humans to be superstitious, invent ghost stories, or be gullible to pseudo-science. To the extent that the Bermuda Triangle phenomenon is not fully understood, breakthroughs will need to be made in psychology and sociology, and I for one have high hopes that someday the phenomenon can be largely nullified by good statistics and science education.

Re:But this would mean?!?!?!?!?

[Gerzel]

Yes exactly water ice in comets. Do you know what a comet's tail is made out of? Water evaporated and removed from the comet by solar radiation.

Correlation does not equal causation

[Marksolo]

Perhaps the change in ocean currents instead of causing the change in magnetic poles is instead caused by the change in the earths magnetism. Just because something is correlated to something else does not mean it is caused by it, the opposite could be true and plenty of other relations are possible.

No - ocean modulates field, doesn't cause it.

[flyingfsck]

TFA and the Slashdot summary are both wrong. The paper doesn't allude that the ocean causes the field. It says that the field is affected (modulated) by the oceans. So the earth could be a permanent magnet, with some of the changes in its field explained by the ocean currents.

Ocean mass vs outer core mass

[cheebie]

I'm highly skeptical of this idea for one reason. The volume of the oceans is MINISCULE compared to the volume of the outer core. In order for the oceans to generate the kind of magnetic field the Earth has, they would need to be highly magnetic. Steel ships orient themselves to the currents automatically type levels. The Earth we see is a wafer-thin skin on the massive iron/nickel mass that is the Earth

Re:Ocean mass vs outer core mass

[John Hasler]

>In order for the oceans to generate the kind of magnetic field the Earth has, they would
> need to be highly magnetic

Salt water is not magnetic at all. It is highly conductive. Look up what happens when conductors move through magnetic fields.

> The Earth we see is a wafer-thin skin on the massive iron/nickel mass that is the Earth

1800 miles is, IMHO, a bit more than a thin skin.

Re:Ocean mass vs outer core mass

[brock bitumen]

i'd tend to agree that 1800 miles is more than a thin skin

but where the hell do you pull 1800 from? Some quick wikipedia'ing shows the earth has a mean radius of 6371km, or nearly 4000 miles, that's radius, so the Earth is about 8000 miles in diameter on average. That's the "body", our "skin", what OP calls the ocean is described as having an average depth of 3790 meters (not km), which is roughly 2.3 miles.

A 2.3 mile thick "skin" is 0.029% of the "body's" total 8000-mile thickness. That, imo, is a thin skin.

Re:Ocean mass vs outer core mass

[John Hasler]

> i'd tend to agree that 1800 miles is more than a thin skin but where the hell do you
> pull 1800 from?

1800 miles of mantle rock over the iron-nickle core. This refutes the claim that the Earth is a ball of iron-nickle with a thin skin over it.

Ryskin should be taken with a grain of salt

[dwarmstr]

I attended a lecture (probably ten years ago at this point) in which he suggested particular mass extinction horizons in the geological column were the result of methane hydrate eruptions. I can't recall the specifics, other than the general disbelief of most of us in the room, on his particular hypothesis. It required a lot of specific proofs that weren't there. There was much discussion on the existence of C60 in various ash levels. And that's all I can remember, other than thinking Gregory Ryskin needs to provide stronger evidence to this hypotheses. But seriously, some of the leading paleontologists and paleoclimate people really thought his stuff was ignoring strong evidence.

Actually, negative

[tjstork]

FWIW, Mars used to have water and may have at one point had a stronger magnetic field than the Earth

Actually, somebody published a paper this week that suggested that Earth's magnetic field might actually accelerate our loss of atmosphere relative to Mars. In fact, Earth right now is leaking atmosphere faster than Mars is, pound for pound. The ionosphere follows the magnetic field lines high up into space, and then the sun just whisks it away.

If this paper and the OP paper stack up, I'd say a good chunk of what we know about the atmosphere just got pissed on.

Re:Actually, negative

[jcr]

In fact, Earth right now is leaking atmosphere faster than Mars is, pound for pound.

Considering how thin Mars' atmosphere is, that's not at all surprising.

-jcr

How much water is in the mantle?

[tjstork]

I guess the question here, is how much water is in the mantle? It seems like volcanic plumes from pretty deep within the earth's crust and below have -steam- pressure in them. One has to wonder if the earth is rather like a giant sponge...a big chunk of rock, yep, but saturated with water.

God built the world for man...

[TapeCutter]

Imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!' This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it's still frantically hanging on to the notion that everything's going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. - D. Adams.

Re:God built the world for man...

[arminw]

.... so the moment he disappears catches him rather by surprise....

Analogy breaks down because the assumption here is that we go out of existence, that is disappear when the body ceases to function. Every human being is more than just the body, but there is an eternal part that transcends its earthly existence. This cannot be proven scientifically but it can be believed and it is believed by millions even still in our scientific age. You can brand such believers fools, but maybe in the end you may be the fool instead.

Re:God built the world for man...

[TapeCutter]

Actually I brand believers as wishfull thinkers, or brainwashed, or ignorant, or arrogant, or oppressed,..., but not foolish, foolish would imply they are stupid. If you listen to the full version of Adam's speech you will find that his metaphor is actually a summary of a rational explanation as to why a bunch of tool making apes were (and still are) predisposed to creating gods in their own image. Once you have convinced yourself of your assumption that there is an invisible man that built the universe especially for human's it's no much of a leap to make the assumption that he gave you an invisible soul that will outlive your body. Not believing those assumptions requires absolutely zero additional assumptions, all it requires is the lack of evidence that you already recognise.

The fact that the original sin was eating the fruit of the KNOWLEDGE tree tells me that the bronze age shaman who wrote it wanted to keep you in the dark, as far as I am concerned the billions of believers reading his words millenia after he wrote them demonstrates he succeded far beyond his wildest dreams.

Re:God built the world for man...

[Ginger Unicorn]

Anything that can be conceived can be believed. So if that is your only metric to be used when evaluating the veracity of a claim, every single claim ever believed by anyone is exactly as valid as every other claim ever believed by anyone else. Even the claims that directly contradict one another. The fact that you have to retreat to the position of "you can't prove it's impossible" rather than having something, anything, at all to back up your claim speaks vast volumes about whether there is any reason at all to accept it.

Re:God built the world for man...

[internic]

I'm interested in seeing the Adams video, but when I follow the link YouTube tells me it's malformed. Can you post a correction?

Re:God built the world for man...

[arminw]

....Actually I brand believers as wishfull thinkers, or brainwashed, or ignorant, or arrogant, or oppressed....

So you would then consider yourself enlightened, free and superior to all of the millions of individuals on this globe who do believe there is a God. That tree of knowledge that you mentioned was a specific kind of knowledge, the knowledge of how to discern good and evil. I believe that the early humans, specifically Adam, had knowledge and insight we have long ago lost.

Natural law tells us that nothing goes out of existence but merely changes form. In order for a human being to go completely out of existence at death, you do have to make the additional assumption, namely that this law does not apply to the human consciousness or mind.

You equate invisibility and undetectability with nonexistence. For thousands of years, before we developed detectors for them, radio waves and other components of the electromagnetic spectrum were not in existence. I am sure you don't believe that. Just because your senses or mind have not apprehended something, does not mean it does not exist. Nothing is ever proved, but you can either believe or disbelieve it.

Re:God built the world for man...

[arminw]

....So if that is your only metric to be used when evaluating the veracity of a claim,...

It is best to use evidence to evaluate a claim or belief. Over the years, our courts of law and legal system have refined the rules of evidence. One of the founders at Harvard Law school, Simon Greenleaf has examined the four Gospels in the light of the rules used in courts of law, and found them to be likely true. You could get that little book from Amazon and read it for yourself. It may even be on the Internet, because his writing has long since come into the public domain.

Nothing is ever proved in a court of law, but the jury is presented with evidence and now must decide whether to BELIEVE or disbelieve either the prosecutor or the defense.

Re:God built the world for man...

[myowntrueself]

The fact that the original sin was eating the fruit of the KNOWLEDGE tree tells me that the bronze age shaman who wrote it wanted to keep you in the dark

Shaman?

Theres an interesting comparison between religion and shamanism. It goes like this:

In religion you are worshiping someone who stands on the other side of a doorway.

In shamanism theres someone standing in a doorway and you are shoving your way past them.

Re:God built the world for man...

[gardyloo]

From http://en.wikipedia.org/wiki/Testimony_of_the_Evangelist (about the aforementioned Greenleaf):

He maintains that discrepancies in their accounts are evidence that the writers are not guilty of collusion, and that the discrepancies in their respective accounts can be resolved or harmonized upon careful cross-examination and comparison of the details (pp 32-35). Greenleaf argues against the scepticism of the Scottish empirical philosopher David Hume concerning reports of miracles. He finds fault with Hume's position about "immutable laws from the uniform course of human experience" (p. 36), and goes on to assert that it is a fallacy because "it excludes all knowledge derived by inference or deduction from facts, confining us to what we derive from experience alone" (pp. 37-38). Greenleaf takes as his own assumption that as God exists then such a being is capable of performing miracles.

Well, that settles that.

Re:God built the world for man...

[arminw]

...Well, that settles that...

It does not settle anything, except that if you were on a jury you would evidently find that the Gospels were fraudulent. There are however millions of people who have found otherwise, coming to faith in Jesus Christ based on the EVIDENCE presented in the Gospels as well as other parts of the Bible. Someday, when we all appear before God, we will find out who is right. It is just too bad for you that by then it will be too late for you to do anything about it. On the other hand, if after death there is only extinction, but those who have put their faith in Christ will not have really lost anything.

Re:God built the world for man...

[gardyloo]

On the other hand, if after death there is only extinction, but those who have put their faith in Christ will not have really lost anything.

Except for a fulfilling life, cognizant of the wonders of nature and science, and unfettered by the worries of Bronze Age mythologies and the gaze of celestial Big Brother.
      I wish the religious happiness, until they start spouting their claptrap, and expect thinking, reasoning humans to accept it based on their words only. Then I get grumpy and fearful for the future of the species.

Re:God built the world for man...

[TapeCutter]

You are putting words in my mouth in the same way you put imaginary facts in your head.

Re:God built the world for man...

[arminw]

....Then I get grumpy and fearful for the future of the species....

You really have nothing to worry about because humans have been religious from the very beginning. There is not a single culture that does not have a religion of one kind or another. The fact is that humans are a stubbornly religious creature. Your atheism or whatever ism you hold to is a religion as well.

Re:God built the world for man...

[gardyloo]

You really have nothing to worry about because humans have been religious from the very beginning.

Oh, good. So every religion is equally rational and "good". Thanks for clearing that up.

Your atheism or whatever ism you hold to is a religion as well.

Ah. So I'm also religious because I don't believe in faeries in my garden, nor in Ra, nor in an animus in every bit of sand on the beach.

Re:God built the world for man...

[arminw]

...Ah. So I'm also religious because I don't believe...

Maybe instead of saying religion I should have said World View. Another way to express this might be called your life philosophy. You apparently are convinced that this world and the time space dimension is all that exists, whereas I believe, as the Bible relates, in the dimension of the Spirit. We were created in this world to learn about respect and love and to thereby prepare us for eternity. This life is nothing more than a school from which we will graduate. Those who refuse to learn will simply flunk out.

If things really are not the way I believe, but turn out to be false, I will have lost nothing. On the other hand if reality is the way I believe and you do not prepare for that other eternal world, you will have lost everything.

Re:God built the world for man...

[gardyloo]

If things really are not the way I believe, but turn out to be false, I will have lost nothing. On the other hand if reality is the way I believe and you do not prepare for that other eternal world, you will have lost everything.

So you're taking Pascal's Wager at face value, eh? All of the arguments to the contrary mean nothing to you? Good luck!

hmm special on discovery showed a liquid metal

[majortom1981]

I am confused. The discovery channel showed a huge experiment done my scientists showing that liquid metal circulating due to the earths rotation would cause a magnetic field. They did this by taking sodium and spinning it in a sphere and it produced a magnetic field. How is this not proof ?

Re:But this would mean?!?!?!?!?

[Daychilde]

Of course water responds to solar radiation - that's how we get clouds! :-)

What?

[spaceguinness]

How does this explain the magnetic fields on Mercury, Jupiter and Saturn?

Re: Rejecting a Hypothesis

[anachronous diehard]

He also says:

There is little doubt that these conclusions will be met with skepticism. And so they should: the results presented by no means constitute a proof. But the possibility of direct connection between the ocean flow and the secular variation of the geomagnetic field is bound to stimulate further research, especially in view of the implications for the question of the origin of the main field.

I think Mr. Ryskin is well aware that he hasn't presented enough evidence to refute the prior hypothesis. He's only pointing out that secular variation has been considered important evidence supporting the dynamo theory. An alternate explanation for the variation wouldn't necessarily falsify the dynamo theory, but it could take away supporting evidence.

But he is correct that this should stimulate further research. His paper mentions enough analytical simplifications and limitations in the source data to suggest thesis topics for an army of grad students. I'm sure there will also be much thought about how the dynamo hypothesis might be independently confirmed.

So let me get this straight...

[XDirtypunkX]

This would mean that the science in "the core" was even more wrong? I didn't think it was possible!

Re:So let me get this straight...

[Jesus_666]

Don't worry, they'll fix it in the sequel where they have to use the alloy "canobtanium" to build a vessel that can bore through water in order to restart the Gulf Strem using hydrogen bombs because without the Gulf Stream's magnetic field Earth will be hit by Africa-sized asteroids. In the end they have the vessel jump out of the water and toss the last H-bomb between the asteroids, blowing them into harmless dust. Then the plucky hacker tells the world end everyone believes him.

Nice joke.

[silentil]

I think this scientist was mixing crack in his testing solutions. Of course when you are on the ocean traversing a ridiculously large ocean current your compass goes nuts because the influence is in close proximity to said ocean current, and thats why commerical divers often get lost. If there is an influence on the earth's magnetic field, it's so pathetically small that my collection of fridge magnets will have an equal effect. Humourous..thanks for the laugh.

Problem of scale.

[Ihlosi]

Earths magnetic field is big (compared to, say, Mercurys, Venus' or Mars'). And compared to the mass of the planet, the oceans are tiny, shallow puddles on the surface. If I were to bet, my money would still be on the "molten iron currents" hypothesis.

Re:But this would mean?!?!?!?!?

[damburger]

Mars also has much lower gravity; basically what determines loss of volatiles is if the radiation impacting on the top of the atmosphere can give the molecules escape velocity. The actual mechanism is a bit more complicated than that, but is ultimately bound by conservation of energy.

Mars also didn't lose all its atmosphere to space - some froze as dry ice.

Re:Especially when we keep crashing planes into th

[rusl]

planes are non-ferrous aluminium.

Re:Electric current and magnatism

[Technician]

I think this is the correct line. The question is then where does the current come from. For that we look a the Aurora. The magnetic field reaches into space and the charged particles from space seperate and enter the atmosphere at the earth's magnetic poles. The current generates a magnetic field, which seperates the charges in the solar wind. How much currnet? Take a look.

http://www.gi.alaska.edu/ScienceForum/ASF5/506.html

This makes more sense to me than a little salt water on an extremely thin crust of the planet.

But there is a molten outer core..

[jlehtira]

We have proven the existence of a molten outer core inside the Earth, and the proof doesn't depend on the magnetic field, but rather, seismology. Sound and vibration can travel in any substance as a pressure wave - material compressing and decompressing (P-waves). In solids, vibration can also be orthogonal to the direction of propagation (S-waves). Think of vibration in a string, or in a tuning fork. It is known empirically that S-waves travel through the Earth only to certain depth. Because they can't propagate deeper than that, the material must be unsuitable for S-waves, which means liquid.

Now, if there's a liquid, a gravitational field, and a temperature difference, convective flow must be present too. In addition, this liquid outer core is circulating around the Earth's axis. So the "geodynamo" still seems like the best explanation to me (I recommend Fowler's The Solid Earth if anyone's actually interested in the science and reasoning behind all this).

the long-term changes (the secular variation) in the Earth's main magnetic field are possibly induced by our oceans' circulation.

This here is what the article actually states. I'm not surprised that oceanic currents can correlate with the details of the magnetic field, as the field is known to be the result of several phenomena. Actually this finding can turn out to be supporting the geodynamo idea, as one problem with the geodynamo is why the magnetic field is such a mess ;). Maybe core currents generate most of the magnetic field and oceans add variation to it.

Correlation is not Causation

[Drakkenmensch]

Oooooo-kay... so the article claim that this could be possible because "water can conduct electricity"... so WHERE is this water-borne electricity coming from, then? We have a magnetic field that surrounds the whole planet, wouldn't that turn the entire ocean's wildlife into fishsticks? Also, when you run electric current through water (such as when you set up a simple electro-plating rig) wouldn't that run nearby compasses nuts?

Bremuda

[Joebert]

And here all this time I thought the Bremuda Triangle was just a clipping error in Gods video game !

In ancient times ...

[rch_slashdot]

... there was little salt, and little conductivity, in the oceans. Where does the remnant field in the rock come from?

By the way ...

[rch_slashdot]

Richard Feynman tells me the earth carries a large negative charge, daily replenished by lightning. This rotates at a mean speed. Will this rotating charge not give (some of) us what we want? - Roger -

The Tail Wags The Dog

[jman.org]

More likely the salt is following the magnetic flow, rather than the other way around.

Don't recall the show, just saw something on one of the science channels wherein some scientists made a planetary model (a big rotating ball of liquid sodium around a free-floating iron ball), their theory being it is the rotational difference between the outer molten core and the solid inner core that causes our magnetic field. In the model, once the thing came up to speed, it generated a field similar to the Earth's magnetosphere.

Also, the field has reversed itself (pointing in to the planet, allowing radiation in, rather than keeping it out) many times. Just check out cores from any long-standing lava flows. We seem to be starting another flip, partially evidenced by holes in our magnetosphere ( ahref=http://news.slashdot.org/article.pl?sid=08/12/17/2352243/rel=url2html-31969http://news.slashdot.org/article.pl?sid=08/12/17/2352243/> ).

If this rotational difference is in fact where our magnetic field comes from, tinfoil had mode says exploiting geothermal energy is ultimately a no-no. Go solar!

Re:The Tail Wags The Dog

[demonbug]

Also, the field has reversed itself (pointing in to the planet, allowing radiation in, rather than keeping it out) many times.

Well, you're right about there being records of many reversals, but wrong about the effect. A reversal does not result in the field "pointing into the planet, allowing radiation in...", it just means that the magnetic north and south poles reverse locations. Instead of charged particles being funneled to one pole by the magnetic field, they would be funneled to the other pole.

Re:But this would mean?!?!?!?!?

[scorp1us]

Actually recent papers published (last week?) actually indicate that the Earth is losing atmosphere faster than Venus and Mars. It seems that the belief is wholly incorrect. It does seem to still prevent radiation exposure though, which is always a Good Thing(tm) Discovery Channel coverage

Would be trouble if true

[mattr]

Recently I heard of a study that showed a major change in the way ocean water flows from one hemisphere to the other is a significant factor in warming data. I'd believe small variations but not the entire field coming from the ocean. That said it might need to be considered regarding aerospace and naval systems.

Updated information about the sodium experiment.

[matmota]

If you mean the experiment at Dan Lathrop's Nonlinear Dynamics Lab, they are doing succesive experiments with bigger and bigger spheres. Last was with a 60cm one, and now they are working on the 3m version which is the one with 13.5 tons of sodium as you mention. According to their webpage:

The three meter experiment now spins under motor control--watch our YouTube movie! We are debugging the system with water as a test fluid, and will soon make Lagrangian flow measurements in collaboration with colleagues from the group of J. F. Pinton. Sodium experiments will follow. More...

There is an article about them from 2008 at Universe Today, and also other people in France were doing spinning sodium experiments in 2007.

By the way...

[raguirre]

There's a chilean cable provider that seems to have been inspired by the Slashdot logo.

Re:But this would mean?!?!?!?!?

[Xonstantine]

Sure it does. High energy radiation hits H2O, splits it into H2 and O, the H2, having a low molecular weight, leaks off into space faster than the O does. Multiply this effect over long time periods, and eventually you have no atmospheric water left.

Perhaps its the other way around.

[BigGar']

I wonder if he might have it backwards. Perhaps the ocean currents are influenced by the earths magnetic field, not so much the other way around.
So one would have correlation, just not in the way posited here.

Wrong title: Ocean current not main cause of field

[QuantumV]

The title and summary gets this paper all wrong. It does not propose that ocean currents are causing the earth's magnetic field. In proposes that many of the small scale variations of the field is caused by variations in ocean currents. The main field is still produced by the core.

Re: overdue... for lunch

[recharged95]

We're overdue now by several thousand years.

Not to sound ignorant, but why is it that we're overdue for:

• some magnetic reversal
• some major earthquake
• some major meteorite impact event
• some major ice age
• some major flooding
• some major solar flare event
• some major ocean current changes
• etc...etc...

We're overdue for everything, such that, I'm overdue for some coffee.

I know it's Monday morning: don't worry about being late.

Re:Especially when we keep crashing planes into th

[MBGMorden]

Not all. Some planes are fiberglass (Piper Tomahawk). Some are aluminum. Some are wooden. Some are quite ferrous welded steel cages with a dope and fabric covering.

I'm skeptical

[DrLudicrous]

This should have appeared as a preprint on the xxx archives first, if it wants to be taken seriously. I see a bunch of math, and a disjointed argument. That sounds alarm bells in my head. I would not really pay close attention to this article until it was cleaned up and resubmitted and/or I heard the author present his ideas live, with the ability to ask questions and get clarifications.

Re:But this would mean?!?!?!?!?

[Klaatuu]

Pedantic mode on. The water ice doesn't evaporate, it sublimates.

Re:maybe not a paper bag per se

[pnewhook]

No, it works with your stock paper sandwich bags..

Re: overdue... for lunch

[Thing 1]

We're overdue for everything, such that, I'm overdue for some coffee.

I know it's Monday morning: don't worry about being latte.

Fixed that for ... me, really, and my entertainment. :)

Opps.

[TapeCutter]

Here ya go, there is a "part two" in the related video's sidebar.

Doh! Geo Induction

[Geotopia]

I don't know why this hasn't been out there for the last century. Pfaw to global warming, this is a real viable theory with reason to explore further. It doesn't mean we toss the theory of a ferrite core which is a natural dipole, but we can examine the strength of the magnetic field taking into account an electronic current running through the fluid currents that "wrap" around the core. For anyone with a strong background in geology, is the current magnetic field explicable with just the ferrite core, or is it too strong? If so, the electrons that move with the currents can explain the increase. If not, then maybe the currents are a result of the magnetic ferrite core...

Re:But this would mean?!?!?!?!?

[bhiestand]

If I understand correctly, the theory is not that liquid water is directly removed by radiation, but that solar winds remove, among other things, water vapor from the atmosphere.

Re:Especially when we keep crashing planes into th

[rusl]

Commercial passenger planes?

Yes, I caught the 2:30 transatlantic flight to Frankfurt aboard a Piper Tomahawk?!

Bad summary of an even worse story

[crmarvin42]

Basically, the newspapers took what the paper said, and extrapolated to an obscene extent. The author of the actual research disavows almost the entire news article outside of having a theory, and it involving oceans and magnetism.

http://www.guardian.co.uk/commentisfree/2009/jun/20/bad-science-magnetism-ocean-core

Complete BS