Bad News for Earth's Magnetic Field

jabex writes "Scientific American's website has an article about the overdue magnetic field flip. According to research published in the journal Nature, it could take anywhere from 2000-10000 years to complete. That's a long time without a protective magnetic field."

Comments

The Earth's magnetic field is overrated

[Rapid Home Offer]

Who needs the Earth's magnetic field, anyways? As long as I have my ozone layer, and my handy dandy lead codpiece, everything is going to be okay.

(Doesn't everybody have a lead codpiece?)

Re:The Earth's magnetic field is overrated

[Ieshan]

Protection from a tinfoil hat, you say?

Brings a whole new meaning to the term dickhead.

Re:The Earth's magnetic field is overrated

[MindStalker]

Lead codpeice, and tinfoil hat. Hmm if you hook a powerful power source between those you might make a human "lifter"

Danger! Danger!

[nystagman]

Just as long as Robert Sawyer isn't correct (and it's very unlikely that he would be, since it was just a novel, damnit) and human consciousness is tied to the magnetic field...

Re:Danger! Danger!

[trinitrotoluene]

Which Sawyer novel was that?

Re:Danger! Danger!

[gui_tarzan2000]

"Just as long as Robert Sawyer isn't correct and human consciousness is tied to the magnetic field..."

However, it would explain a lot about the lack of common sense in our population in recent years...

cautionary notice of threatened death.

[mkavanagh]

any mention of a certain bullshit hollywood production with the shittiest scientific basis for a film since the neverending story will result in death. of the poster. thanks for not getting yourselves killed.

Re:cautionary notice of threatened death.

[dont_think_twice]

You mean The Core?

Re:cautionary notice of threatened death.

[Emperor Igor]

Hey, I liked the Neverending Story. Well, the first one, anyways. I liked the theme song, too.

"Don't you die on me, puppy-dragon!"

(Okay, so that wasn't an actual quote, but it was such a surreal movie, it might as well have been.)

Re:cautionary notice of threatened death.

[cpt kangarooski]

I liked the Neverending Soda.

no magnetic field, really?

[Bastian]

I'm no geologist, but it seems strange to me that in the process of a magnetic field reversal the earth's magnetic field would just go away for a few thousand years. Wouldn't the field just rotate over time, so that the magnetic north pole continues to drift until it is near the geographic south pole?

Re:no magnetic field, really?

[JGski]

It's apparently far more complex.

From what I've read on the web and seen on a PBS Nova program about the subject: during a flip the Earth's internal dynamo goes from ordered to chaotic. The movements is not just is a straight bee-line to the opposite side. The North pole, for example, has been drifting even of the last 30 years toward the south east. The field strength declines substantially and the magnetic fields change from bipolar (two poles: north and south) to multipolar ("poles" coming out of any which direction - the "Southern Anomaly" in the south Atlantic is apparently believed by some to be the onset of a tripolar field). When the actually collapse is imminent, these poles start moving quickly, as much as degrees of latitude or longitude per day or week.

Re:no magnetic field, really?

[therealmoose]

No, it's quite complicated (somewhat like a fluid system). Regions of the field spin around, strengthen, weaken, and drift around in complex 3d patterns for thousands of years according to the models (confirmed by geological finds). The net effect is that the field is significantly weaker (due to the lack of a uniform makeup, in part) and in some regions, some of the time, effectively nonexistant. It is not sufficient to deflect the radiation that it currently does while 'flipping'.

Re:no magnetic field, really?

[umofomia]

From what I've read on the web and seen on a PBS Nova program about the subject: during a flip the Earth's internal dynamo goes from ordered to chaotic.

Yep... I've seen this Nova too. It was pretty interesting. For the rest of you out there, here's a link to the show's web site, where you can also see an animation of a computer simulation of a polar reversal. During the reversal, the earth could have poles coming out of the equator even, and if you were able to witness it, you would even see auroras around those poles.

Re:no magnetic field, really?

[maraist]

I'm nervous pointing this out, but in our E&M class we were directed to a pseudo-science web site (our professor assures us that the presented pseudo-science violates certain well understood principles).

But among the dozens of pdf's this web site provides, one is on the ocean rift polar flips.
rift.pdf

In short, what it says is that as the mid-atlantic rift rips apart, hot magma comes to the surface, and that liquid is a lesser magnetic conductor (lower permeability) than the pre-existing high iron-content solid's crust. This plus the 1/r^2 magnetic strength of the source of earth's magnetism (namely the core of the earth) mean that the magnetic fields generated by the solid crust to the left and the right of the mid-atlantic fissure are MUCH stronger than that of the distant core.

The effect of having a closer magnet oriented in the opposite direction is that the next cooling layer of magma will orient it's magnetic field in the opposite direction of the previous layer (to complete the regional loop). Thus every new mid-atlantic fissure eruption / layer, causes a new anti-parallel magnetic field... Presumably, this is what geologists are measuring when they find magnetic poles pointing in differing directions.

As another warning, the wesite uses it's pseudo-science to demonstrate that certain E&M effects would be greater than our classical E&M says it would be for such a fissure reverse polarization.. So please take with a grain of salt.. None the less, I tend to like simpler solutions than a chaotic tri-poled earth magnetic field, or whatever currently is the explanation.. The crux of this pdf makes intuitive sence from a lay-persons' perspective.

Re:no magnetic field, really?

[CheshireCatCO]

"None the less, I tend to like simpler solutions than a chaotic tri-poled earth magnetic field, or whatever currently is the explanation."

Yes, but surely you like an explanation that is *accurate* even more than you like one that is simple. I mean, I can think of simpler explanations for the striping quite easily. (Like, "There is no striping. These are not the droids you're looking for...") But they probably wouldn't reconcile with the various data very well. :-)

(Also, magnetic fields fall off as least like 1/r^3. The lowest order moment is a dipole, remember. At least until someone finds a magnetic monople, anyway.)

To get at the article you linked:

First of all, it suggests that the planets' fields are all oriented the same way with respect to their spins. Not true. See my post, above. Jupiter's field is oppositely oriented to that of Earth, for example.

It goes on to "point out" that Uranus's field is aligned with it's odd spin vector. Surprisingly little research with Google would have shown that to be very wrong. Uranus's spin and magnetic field axes are about 60 degrees apart. That's no where near alignment.

He (I'll assume that the author is male) procedes to blame large amounts of cobalt and iron in Earth's crust for the slightly off spin axis magnetic field axis. Large amounts? The overwelming majority of Earth's iron is in the core or mantle, not the crust. What is in the crust is fairly evenly distributed. It's hard to imagine that the symmetry is broken that much, isn't it? (Sorry I don't have the raw numbers for the distributation, but I doubt that anyone has worked it out.) But if the iron in the core wants to direct the field along the spin axis, how is the miniscule amount of iron in the crust going to "redirect" that field significantly over global scales? (Sure, you've got a bigger lever-arm at the crust than the core. But only by a factor of a few. We're being told that that offsets the massively higher concentration of iron in the core.) Also, why is Earth's field offset as well as titled? (No lever-arm helps you with that one.)

Another interesting error is the (apparent) assertion in the tidal breaking section that Earth will eventually spin 1/28 as fast to match the Moon's orbital period. That's half true, we will match the Moon's orbital period in about 5 billion years. (Just in time to be destroyed by the Sun's red giant phase. Yay!) But a simple knowledge of conservation of angular momentum tells you that we won't be spinning once every 28 days. It's more like a 89 day period, if you work it out. (Funny how he can use conservation of energy to apparently bolster his case when he wants to, but doesn't know what conservation of angular momentum is. While both are adhered to, with the latter it is much harder to "fake" a violation.)

Next up... mass extinctions. He claims that palentologists have determined that they (the extinctions, not the palentologists) occur every 32 million years. Hm. About five mass extinctions in the history of the Earth (the last 65 million years ago) are known (http://www.bagheera.com/inthewild/spot_massextinc tions.htm) spanning back 440 million years or so. That's 380 million years and 4 intervals between them. Quick math check... I get that that's one every 95 million years. (Is that what you get, too?) For proving that exctinction events aren't caused by impacts, that's pretty weak. (Based on the cratering record on the Moon, mainly, the calculated interval between mass exinction causing impacts is about 100 million years. Roughly speaking.)

Next bit of funniness. He claims that "Therefore a reversal in ion polarity would indeed reverse the Earth's magnetic field;" and then goes on to try to show that this is silly. Which is a strawman, since I don't know anyone who asserts that the ions will reverse polarity. How do you get ions to reverse polarity?? Unlike in chemistry, ions in astronomical contexts are essentially

Re:no magnetic field, really?

[meringuoid]

How do you get ions to reverse polarity??

Normally you'd begin by modifying the deflector dish.

Re:no magnetic field, really?

[lowmagnet]

For some reason, I want a Pepsi after watching that video.

Re:no magnetic field, really?

[solarlux]

I think you are referring to the "South Atlantic Anomaly" (not "Southern Anomaly")...

Re:no magnetic field, really?

[merlin_jim]

Finally -- and this is only because I'm tired of debunking this nonsense, not because he is done spouting it here -- materials don't "focus" magnetic fields as he describes. He makes it sounds like metals suck in field likes so that they pass through them. Field lines stay tied to whatever electically charged material they run through, but that's about it. You can superimpose fields, to be sure, but you can't just alter a field like without affecting the source.

Look up FEMM and play around with it a little... it shows that materials do indeed focus magnetic fields, and is generally accepted in the field as an accurate simulation tool. I just googled for the link: http://femm.foster-miller.com/

Also you might want to look at hall sensor designs; most of them involve using an iron nail or similar device in front of or behind the hall sensor, in order to focus the magnetic fields through the sensor.

As an experiment, take a soft iron cylinder, and put a strong magnet inside it. Don't let the magnet actually touch the walls of the cylinder, because that would magnetize the walls... wrap it with newspaper or something... screw the endcaps on... now if the field lines are passing through the metal, then you will be able to measure them from outside. However, if field lines tend to go through magnetically permeable materials, then they will go entirely through the cylinder and not be measurable from the outside.

It's called magnetic shielding, and it requires the very property you say doesn't exist.

Guess what? When I order magnets from forcefield.com, they ship in exactly that sort of container.

Re:no magnetic field, really?

[barakn]

None the less, I tend to like simpler solutions than a chaotic tri-poled earth magnetic field, or whatever currently is the explanation.

The sun provides an interesting example of polarity flips, which only take 11 years and thus are fairly well studied. The way it does it is different than Earth, as the sun's convective layer is what produces the field, and the convective layer extends to the surface. None the less, during the flip, the sun's surface sprouts many magnetic poles, almost always in pairs. We call them sunspots. Current theory suggests that the polarity flip actually occurs because the sun sheds the old polarity like a snake sheds its skin. It's not the sunspots or x-ray flares themselves that do it, it's the gigantic explosions known as Coronal Mass Ejections that violently heave enormous quantities of magnetic gas/plasma into space. The Earth can't shed a magnetic field this way, which might help explain why it takes so long. Multipole explanations of polarity flips are not that esoteric.

Re:no magnetic field, really?

[CheshireCatCO]

I didn't say shielding doesn't occur. Of course it does. Materials can definately alter the paths of field lines that would otherwise pass through them. (Superconductors, for example, actually expel fields, up to a point.)

I said that the presence of iron doesn't magically reach out and grab field lines, dragging them through the metal, when they were originally running high above the Earth's surface. That's what this article was implying iron in Earth's crust was doing. Unless you know of a way of doing that.

Re:no magnetic field, really?

[merlin_jim]

Sorry I obviously didn't RTFA.

Oh and BTW, Superconductors don't expel field lines exactly; they precisely resist all changes in magnetic fields; they are an infinite inductor. If a magnet is sitting on a superconductor when it goes critical, as the super conductor approaches critical it will become extremely diamagnetic, expelling field lines. When it goes critical, however, all field lines are trapped in place. This is where the standard magnet hovering over a superconductor spinning on its poles demo comes from; the poles are held in place by the trapped field lines.

Nature hates infinites, right? So how can a superconductor have infinite inductance? It does, up to a point. Once the magnetic flux through the superconductor reaches a certain level, depending on the particular type of superconductor, it either a) becomes non-superconducting due to peculiarities in the magnetic orientation of the superconducting components or b) the magnetic flux is greater than the material strength and it undergoes structural failure.

Just FYI, Bismuth and water are both diamagnetic; but their diamagnetic force is 10-13 orders of magnitude weaker than a standard lodestone...

And tonight I get my first up close and personal look at a really big superconductor. From the inside. I'd be excited if it weren't for the excruciating pain in my knee...

Re:no magnetic field, really?

[radtea]

Where is the corresponding north pole? The one thing we can be fairly sure of is that however many poles the Earth's magnetic fiedd has, it'll be an even number. Although I guess it's possible for multiple poles to overlap, giving the appearance of an odd number.

--Tom

Re:no magnetic field, really?

[JGski]

Multiple north poles could have the same orientation, sort of like with a Laplace transform where multiple poles or zeroes can be at the same frequency.

Re:no magnetic field, really?

[AlecC]

Or have what is essentially a Y-shaped magnet, with one big South pole and two spatially separated North poles, or vice-versa.

Re:no magnetic field, really?

[Tukla]

Next bit of funniness. He claims that "Therefore a reversal in ion polarity would indeed reverse the Earth's magnetic field;"

My guess is he was watching Star Trek when he wrote that. Just imagine Leonard Nimoy saying it.

Reversal of Magnetic Field = No Magnetic Field?

[Spock the Baptist]

I didn't see any mention of a loss of the Terrestrial Magnetic Field in the article, only a change of polarity. The two (polarity reversal, and field loss) an not necessarily equivalent, at least over long time scales.

Re:Reversal of Magnetic Field = No Magnetic Field?

[Spazmasta]

From what I read, it sounded like the time of "no magnetic field" was the time during the reversal process - after the reversal is over, everything will be just fine, it's the process that we're worried about, where the magnetic fields aren't quite aligned like they are now, but scattered in a way to diminish the protective effects we get from it.

Re:Reversal of Magnetic Field = No Magnetic Field?

[Anonymous Coward]

"After the reversal is over, everything will be just fine"

Except all the magnetospheric texbooks will need to be rewritten to add negative signs to eveything. As a graduate student in this field it fills me with a certain dread to think about relearning all this stuff.

not to worry!

[Tumbleweed]

I'm sure the Highlander will invent a shield to protect us when the time comes.

Dipole to quadrupole to reversal...

[lcde]

I can't find the article on google right now, but the last time i read about this in between the reversal of earths magnetic pole it turns into a quadrupole or higher order for a couple of hundreds of years then it finishes.

Still we won't lose our magnetic field unless our core solidifies, but a field reversal or a higher order magnetic field will allow different polorization of solar winds and other EM noise that would be different that what we have now. We also might not be as well protected against the solar flares during the sun's cycle.

Man this is pathetic reporting.

[QuantumG]

Article has next to nothing to do with the blurb.. maybe the Slashdot "editors" should RTFA before posting.

mutations?

[nomel]

Maybe all the particles from the sun that will hit us will cause mutations! Maybe that's what happened before.

I can see it now...
"Play hard, play tough. Nike lead lined athletic wear."

Re:mutations?

[qengho]

"Play hard, play tough. Nike lead lined athletic wear."

Heh. If Nike could come up with a substance that blocks magnetic fields, they could retire from the clothing industry. But playing along with your premise, the ads would probably be pitched at the Entitled Rich:

Sign up now for Dr. Mengele's Sure Protection Of Reliable Traits and assure the survival of your gene line! Qualified applicants only. Vee vill determine who iss qvalified."

Re:mutations?

[ttfkam]

Maybe particles from the Sun that have hit us have already caused mutations! Maybe without genetic mutations we all wouldn't be here!

Insightful indeed...

Re:mutations?

[nomel]

yes! Looking into this a little more, the time figure are close...

Perhaps this explains the jumps in evolution observed every 100,000 years or so.

from this article
"The time between magnetic reversals on the Earth is sometimes as short as 10,000 years and sometimes as long as 25 million years; the time it takes to reverse is only about 5,000 years."

Someone should look into this!

Get ready for a new body! Woohoo! :p

.

Re:mutations?

[Anonymous Coward]

Yes, the solar wind particles are going to penetrate 100km of dense atmosphere to hit us.

Can GPS substitute?

[Thinkit4]

So our compasses would be screwy. Couldn't we use GPS to give direction?

Re:Can GPS substitute?

[bluGill]

Learn to navigate without a compass. I live in an area with many iron deposits, we learned long ago that a compass is not a reliable tool for navigation. We learn other tricks. (Starts at night, guesstimate the time and use the sun during the day). Combine that with knowing about what the land should look like and you can get close enough. Not as easy or are reliable a a compass in other areas, but it works.

Re:Can GPS substitute?

[thomastheo1]

what if you have to navigate a wal-mart parking lot on a a cloudy day?

Re:Can GPS substitute?

[sharkdba]

Starts at night, guesstimate the time and use the sun during the day

You have the stars at night.

The poster is a moron

[psyconaut]

"That's a long time without a protective magnetic field".

Actually, haven't you wondered how life existed during previous flips? We don't lose our protection....it's polarity shifts....

-psy

Re:The poster is a moron

[Phexro]

Thank you, I was about to post something similar.

It's a long time to us puny humans, but it's the blink of an eye in the planetary timescale.

Re:The poster is a moron

[psyconaut]

I think people think that the magnetic poles are like a battery that can only flip betwene positive and negative...they are constantly moving (magnetic north has strayed to Russia, but is currently in Canada), and they vary in strength.

And, as you so rightly said: we're far too insignificant to be wiped-out by something of cosmic proportion or scale :-)

-psy

are we sure Halliburton

[morelife]

or one of its subsidiaries isn't doing this remotely?

You sound as if you know what you're on about...

[leonbrooks]

...yet there are records stamped in lava of massive (in excess of a right-angle from the PoV of the region sampled) pole-swing which took place in 90 minutes or less.

Mercury has a reasonable magnetic field, yet shouldn't be large enough to still have much fluid inside. Mars has negligible magnetism, yet is many times larger than Mbeercury. Venus is in many ways comparable to Earth, yet no serious field. It can't be the retrograde spin, because Uranus spins on its side and has quite a strong field - laterally offset from the core and steeply angled. It is quite clear that our current ideas about planetary magnetism are at best whistling in the dark.

They have plenty of company. Our current ideas about cosmology are based on principles under which the GPS system would not work. To really drive the point home, the military people had to correct their initial GPS software after writing it according to cosmology and not to observation - they even had to be shown using a test satellite because they were so sure that the theory was right.

In this case, the broken bit of theory is that photons lose energy as they climb through a gravity field. They don't. The wavelength is altered by the emitter's position in a "gravity well", but does not change as the photon travels in or out of the well.

Naturaly, this completely invalidates everything currently based on expansion-redshift, a concept intimately tied into the same principle - which means bye-bye to big-bang cosmology. That's distressing for the status quo, but a good thing for science because we now have an opportunity to shrug off the dud theory and find something which better fits observation.

Happily, there are several steady-state-ish concepts being bruited about which continue to match the observed data at least as well as any big-bang-ish theories while managing to avoid conflict with this particular observation.

My current favourite is one which features a changing ZPE, since this also neatly explains the "steps" observed in redshift (including midway through galaxies!). While this arrangement doesn't require galactocentrism up front (ie, the "steps" should appear to be the same when viewed from almost anywhere in the universe because the changes which produce them are, well, universal), it is buried in the fine print, in particular the part of the model which deals with the CBR (and matches it much more closely in general and in detail than any big-bang model I've seen). Some punters will argue that the redshift-stepping isn't really there, but I've not seen any of those arguments come close to surviving serious examination.

In case you've siezed on the wrong idea, I make no claim to deep understanding, I'm neither astronomer nor physicist, I know barely enough to clearly discern why big-bang is broken, but I do know enough to be sure that it is.

Goodbye Van Allan Belt, Hello Cosmic Rays

[StateOfTheUnion]

The original linked article isn't very informative. There will probably be a period of no significant magnetic field while the field is reversing . . . Here's an article about a simulation that to everyone's surprise, actually predicted the reversal.

Goodbye Van Allan Belt, Hello Cosmic Rays . . .

Way Overdue

[jazman_777]

The magnetic field flip, the super-volcano in Yellowstone, the San Andreas Fault, the demise of SCO. Have I missed anything? A Red Sox or Cubs World Series winner?

Re:Way Overdue

[Anonymous Coward]

Have I missed anything?

The second comming.

I for one...

[wronskyMan]

welcome our new cosmic ray overlords! (Well, for at least a couple thousand years)

Re:You sound as if you know what you're on about..

[CheshireCatCO]

Appart from the general off-topic nature of that rambling post, it shows a poor understanding of the data, unless someone has utterly failed to clue me in on some breaking developments in astronomy. (Possible, but my collegues like talking about their work too much for me to think that that's likely.)

You'd better show me a paper that suggest that gravitational redshift doesn't happen, because I have yet to hear of it. And since that'd be Nobel-quality work, showing that GR breaks down (where it should hold up), I'd be surprised if the research happened. In fact, I attended an entire comps on GPS. While GR was certainly discussed, since they need to take it into account for GPS to work, no corrections to that theory were mentioned. Seems sort of odd that the speaker would talk about GR without mentioning that it broke down.

And I have yet to see a steady-state model that matches the data very well at all. The whole "cosmic microwave background" thing is hard to get around. Since I just attended a lecture by a well-known cosmologist and he didn't say a word about the Big Bang being "broken", I will have to once again ask you to back up your rather grandiose assertions.

As for planetary magentic fields:

There are lots of ways that Mercury can have a fluid core, still. The most commonly argued one is to have more sulfur mixed in. This should lower the freezing point sufficiently to keep it molten still. It's also worth noting that Mercury has an unusually large core for its size. This might play in to things.

Mars lacks a global field (today) because it has almost certainly cooled off too far. (If we assume the same composition as the Earth, anyway.) This is supported by the lack of ongoing volcanism or tectonics, which also require a molten interior to proceed. However, in the past Mars *did* have a global field. This is quite consistent with the theory, since it would have been warmer inside.

As far as I know, no one has ever suggested that Venus's retrograde spin is the cause of the lack of a magnetic field. That's fairly silly, since the field doesn't know which "way" the planet is spinning anyway. (Magnetic field on other planets are can be found oriented both ways with respect to their planets' spins and we know that Earth's field has changed direction.) However, the astute person would have noticed that Venus does spin very, very slowly. This would generally lead to a small or non-existant field, since planet spin is thought to be tied in to the dynamo process. (There's a strong correlation between field strength and planet's angular momentum, for example.) Of course, Mercury only spins 3 times faster, but that's still something.

I'd also love to see your proported research showing field changes if 90 minutes or less. How in the heck do you DATE to that accuracy? You can't, unless you pretty much just watched it cool. (In which case, why didn't every compass on Earth notice the switch?)

No one is saying that we totally understand cosmology or magnetic dynamoes. But to suggest that we're "whistling in the dark" is to down-play the wonderful and careful work of far too many people to let you get away with saying that here. We might not have the details all down, but I'd say that we're doing alright on the theories.

It Came From the Core of the Earth!!!

[dexter riley]

Oh, relax. The Core was just a 1950's science-fiction movie with modern glitzy effects. Unobtanium! Sonic drills punching holes in the sides of mountains! Reversing the ship's polarity! If you had gone in accepting that it was a B movie, minus the men in rubber monster suits, you would have had a much better time.

Anyway, I'll go out on a limb here and recommend you skip The Day After Tomorrow , coming soon to a theater near you.

If we have no magnetic field...

[Jorkapp]

Without a magnetic field, we will have (comparatively) little protection against gamma rays from the sun. There are only 3 solutions to living on earth without a magnetic field:

1) Living above ground with SPF 10000 sunscreen being constatly applied
2) Living above ground with a Class 5 hairiness - like those seen on Steve Allen and CowboyNeal
3) Living below ground

Since I hate putting on sunscreen, option 1 is ruled out. Since I don't like Steve Allen, option 2 is also ruled out.

Thus leaving us with option 3. Underground living. It seems bearable. As long as CS is still playable under 30m of bedrock, I'm happy.

Re:If we have no magnetic field...

[Patrik_AKA_RedX]

Why worry? I carry around a cellphone, MP3-player, PDA, laptop and an electronic watch. So I've got my own electromagnetic field to protect myself against cosmic rays.

Re:If we have no magnetic field...

[Anonymous Coward]

Arrgh!!! I hate that goddamn movie the Core so fucking much. Gamma rays are EM waves, a magnetic field is not going to do anything to deflect them. Any gamma rays that hit us with no magnetic field were already hitting us when we had it. The magnetic field deflects solar wind particles, which would have been absorbed by the atmosphere (northern lights) if the magnetic field were not there.

Re:If we have no magnetic field...

[srn_test]

Gamma rays? Explain how uncharged gamma rays interact with the Earth's magnetic field.

For bonus marks explain why visible light isn't also effected...

Is this what's happening in Sicili?

[Steven Reddie]

Earlier Slashdot story: Technology Spontaneously Combusts In Sicily

Re:Is this what's happening in Sicili?

[Tuscahoma]

Wouldn't that be fun? Global spontaneous combustion of electronic devices as the magnetic reversal progresses. End of civilization anyone?

Re:Is this what's happening in Sicili?

[Steven Reddie]

The Ludites would be very pleased.

punctuated equilibrium

[orn]

The fossil record shows that the Earth goes through periods of time where there is an incredible amount of speciazation - new critters pop into being very quickly. I've read other stuff that suggests that this is simply due to the die-offs: since there's a niche available, something moves to fill that niche.

Could this be a contributing factor or even a causative agent? The normally low error rate in genetic reproduction takes a big spike due to more particles getting through the Van Allen belts?

Re: punctuated equilibrium

[Black Parrot]

> Could this be a contributing factor or even a causative agent?

IIRC, someone has looked into this and found that there isn't any correlation between the reversals and die-offs.

Re:punctuated equilibrium

[Anonymous Coward]

Could this be a contributing factor or even a causative agent? The normally low error rate in genetic reproduction takes a big spike due to more particles getting through the Van Allen belts?

It could be even simpler than that. Evolution is essentially the movement towards a creature that is better suited towards the environment it is in. When that environment changes rapidly, there will be loads of ways in which a population could differentiate itself to become a better match.

Re: punctuated equilibrium

[Tablizer]

IIRC, someone has looked into this and found that there isn't any correlation between the reversals and die-offs.

Well, I did see a heavy cell-phone user with 3 eyes.

Yeah, yeah, yeah...

[leonbrooks]

someone has utterly failed to clue me in on some breaking developments in astronomy

Think Copernicus. Tell me of any seriously revolutionary idea which you know was accepted with open arms by all.

You'd better show me a paper that suggest that gravitational redshift doesn't happen, because I have yet to hear of it.

Of course not. You wouldn't hear good things about Linux in any Microsoft-sponsored presentation either, and wouldn't expect to. If you don't expose yourself to anything but orthodox dogma, why would you expect to understand heresy?

arXiv censored one of the clearest presentations, but try, from the start, no less than "A. Einstein, Relativity: The Special and General Theory" in which he says "An atom absorbs or emits light of a frequency which is dependent on the potential of the gravitational field in which it is situated." Not on any delta-G it travels through. Was he right? If so, the heresy was always present, and the high priests of cosmology have simply failed to acknowledge it.

J. H. Taylor, in "Astronomical and Space Experiments To Test Relativity," in General Relativity and Gravitation (Cambridge Uni Press, 1987), compares atomic clock time with pulsar timing data and concludes "Here is direct proof, based on a clock some 15,000 light years from the solar system, that clocks on Earth run more slowly when the moon is full - because at this time of the month we are deeper in the gravitational potential of the sun!" Looks like he was on Albert's side.

Seems sort of odd that the speaker would talk about GR without mentioning that it broke down.

Probably mostly because it doesn't break down at all. (-:

"Redshift" (frequency changes) produced by one's position in a gravity well is part and parcel of GR. Redshift produced by a change in gravitational potential isn't.

Since I just attended a lecture by a well-known cosmologist and he didn't say a word about the Big Bang being "broken",

"I just attended a talk by a Newtonian physicist and he didn't say a word about physics being broken"? (-:

Consider the pennies-on-a-balloon model of cosmology. Why should the balloon stretch and the pennies not? Is that not a special pleading unsupported by any verification or experimentation? Why should space strecth on a large scale and not on a small? Shouldn't such an effect be visible in the outer galaxies of a cluster? Or vary in the space surrounding a cluster? That's not science, that's dogma.

It also utterly fails to deal with stepped redshifts, as evidenced by visual observation of large samples of galaxies, and of Gamma Ray Bursters. Nor does it cope with the "excessive" brightness of distant galaxies, nor with closely associated galaxies featuring differing redshifts. And this is but the beginning of its troubles.

Knock out the "special pleading" by allowing space to stretch more or less uniformly, and you wind up with a galaxyless, even starless universe from a big-bang start.

And I have yet to see a steady-state model that matches the data very well at all. The whole "cosmic microwave background" thing is hard to get around.

Steady-state-ish. I'm favouring a system which has achieved an essentially steady state, not one which always was steady.

In this case, one doesn't have to "get around" CBR at all, since it fits nicely as the redshifted remnant of a cosmic "flame front" of galaxies and/or stars. The observed CBR variations fit nicely as well. On top of that, it also solves the "dark night sky" issue far more neatly than does entrenched cosmology, and a big long laundry list of other conundra.

[this is too long now, planets coming in a second reply]

Re:Yeah, yeah, yeah...

[BerntB]

Tell me of any seriously revolutionary idea which you know was accepted with open arms by all.

But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.

-- Carl Sagan

Also note that there are quite a few more clowns than very good and misunderstood scientists. :-)

Etc, etc.

Go read a book on the scientific method.

Re:Yeah, yeah, yeah...

[CheshireCatCO]

In other words, you have nothing that you can put forth to show what you're talking about. You're resorting to accusing scientists of censoring your results, when in fact we'd be all *over* something revolutationary and new. History is full of examples of this: GR was generally quickly accepted. So was quantum mechanics (the best and brightest young physicists flocked to it in the early part of the 20th century). The Giant Impact model of the Moon's formation took hold quite quickly, too. Sure, we don't just drop an old position. But scientists will listen to new data and theories and if there's anything there at all, usually you'll find a number of them quickly jumping into the new field. (That's how you make a name for youself, after all.)

Basically, your post has all the hallmarks of a crackpot's rantings, I'm sorry to say.

years

[Googo]

2000 years, 10000 years, its all the same thing. Its just another day at the park.

When you wish upon a planet...

[leonbrooks]

However, the astute person would have noticed that Venus does spin very, very slowly. This would generally lead to a small or non-existant field, since planet spin is thought to be tied in to the dynamo process. (There's a strong correlation between field strength and planet's angular momentum, for example.) Of course, Mercury only spins 3 times faster, but that's still something.

This had me giggling. (-:

OK... so if Mercury spins 3x faster, it should have roughly 3x, or 3^2x the field depending on how your dynamo works? It's about 0.7% of Earth's field, and Venus' is less than 0.06%, which doesn't work either multiplied or by multiplied by the square, particularly with mass factored in. But it still spins roughly 90x slower than Mars... which has a field only twice as strong as Venus'. Venus has not cooled as much as Mars, but OTOH Mercury's core has to have cooled much more than Mars'. And for all of Jupiter's spectacle, a magnetic field only 8x stronger than Earth's is pretty disappointing, given all of that mass and spin, and that cold compressed H2 is metallic. Is this all producing as little rhymne or reason for you as it is for me?

MESSENGER will be fun, when it starts telling us stuff.

<aside> Mars has patches of magnetised rock, but no serious field today. This is said to imply a strong field in the past, but maybe not.

One of the few forces which explain nearly all of the features of Valles Marineris is lightning (pardon the kind of bolt which could leave a scar 3000km long! - but water, sand and tectonics don't explain much) which would imply (there's that word again) an essentially singular event and also explain a lot of loose rock scattered around on the surface of Mars. Such an event would be big enough to magnetise mucho rock, and/or disrupt an existing magnetic field. Until we can explain VM, we might be struggling to explain a few other features of our solar system as well. </aside>

As for Uranus and Neptune, I'm not sure I'd actually describe a 60% tilt (plus lateral offset) as "aligned" in the conventional sense of the word... and right next door gyrates Saturn, with the magnetic axis apparently perfectly aligned with the spin axis.

How you'd set about reconciling a dynamo theory with the lesser gas giants is beyond me. John, if you do try to explain it (as many great men have tried to do in the past) please give me time to sell tickets. (-:

[field changes next]

Re:When you wish upon a planet...

[CheshireCatCO]

"OK... so if Mercury spins 3x faster, it should have roughly 3x, or 3^2x the field depending on how your dynamo works?"

Well, it isn't linear, for one thing. Why do you assume that it is? Do you know anything about dynamo theory? (The non-linearity is what makes it such a thorny field in the first place, after all.)

"One of the few forces which explain nearly all of the features of Valles Marineris is lightning"

I'm not sure that this even deserves a reply. This is just too bizarre. Valles Marineris is way to big to be carved by lightening.

On the other hand, while you causually dismiss erosion and tectonics, you probably should step up to the plate and explain the Grand Canyon on Earth (erosion-caused) and the Himilays (tectonics). And while you're at it, you can use your lightening "theory" to explain the Tharsis Bulge on Mars.

"How you'd set about reconciling a dynamo theory with the lesser gas giants is beyond me."

What's to explain? The usual suspecion is that they have oceans in their mantle with ions dissolved in them. This would do the trick nicely, just like it does on the icy satellites of Jupiter.

Why you're worried about the tilts, I'm not sure. No on said that magnetic fields have to be perfectly aligned with the spin axes. Your failure to recognize that is just that: your failure.

Re:When you wish upon a planet...

[Ayaress]

Mars is a lot smaller. Small objects loose internal heat faster because of a higher area:volume ratio. Mars shows extensive evidence of having lost its internal heat. Some evidence suggests it still has enough to melt ice and produce steam, but...

Venus shows extensive evidence of still having at least some of that internal heat, and displays "recent" volcanic activity (much more recent than Mars at any rate, and it's atmosphere is comprised mostly of common volcanic gasses) on a nearly planet-wide scale.

Now, what you have is basically two dynamos.

One of them is spinning fairly rapidly (Mars spins almost as fast as Earth), but has nothing inside to generate a substantial field.

The other has the material needed to generate the field, possibly just as much as Earth does, but rotates extremely slowly.

Now, as for the lesser gas giants, dynamo theory HAS been reconciled with thier freakish multi-poled magnetic fields. It was even on Slashdot not long ago.

Furthur, a lightning bolt that could carve a trench the size of Valles Marineres would not produce what we see. It would produce mostly glass.

Ever seen where a powerful bolt of lightning struck the ground? If you carefully dig it out, you can find a VERY fragile glass-like structure resembling a taproot.

Most storms won't produce these. You see, your average lightning bolt on Earth can't even ignite wood unless it's very dry. The most powerful ones can melt tiny dirt particles. However, these bolts are lucky to be an inch wide, and they don't last long enough to do any damage to rock or much damage to soil (they're mostly limited to lighting shit on fire, and fire doesn't cut through a thousand miles of rock).

Now, assuming a linear relation (which it isn't, but this is much more forgiving on your theroy than the proper calculations), a bolt of lightning 100 miles wide, that is powerful enough to VAPORIZE rock thousands of feet deep, and lasting long enough to track accross 3000 miles of terrain is FUCKING BIG. My calculator overflows at 10e9999, and it overflows before I get to the 3000 mile long track part. Which is good, because lightning doesn't typically "track" along the ground. It stirkes a single spot, dissipates all its energy, and stops. To get a spark from a tesela coil or something to track, you need to constantly cause a voltage between it and the target faster than the bolt dissipates it. Lightning doesn't work that way.

Nothing can generate the kind of lightning bolt it would take to carve the Mariner rift, and even if it COULD, it wouldn't look like it does now, because right now, it looks a hell of a lot more like the African rift valley than it does like a tektite glass field.

Right turn, Clyde... magnepole-nastics

[leonbrooks]

I'd also love to see your proported research showing field changes if 90 minutes or less. How in the heck do you DATE to that accuracy?

You don't. See, for example:

Mankinen, E. A., Prévot, M., Grommé, C. S. and Coe, R. S., 1985. The Steens Mountain (Oregon) geomagnetic polarity transition, 1. Directional variation, duration of episodes, and rock magnetism. Journal of Geophysical Research, 90:10,393-10,416.

[ditto] 2. Field intensity variations and discussion of reversal models. Journal of Geophysical Research, 90:10,417-10,448. Return to text

Coe, R. S. and Prévot, M., 1989. Evidence suggesting extremely rapid field variation during a geomagnetic reversal. Earth and Planetary Science Letters, 92:292-298.

These guys were getting firm evidence of up to 8 degrees per day, but there are more reports to read if you want them.

You're right to be surprised, though, 'coz Nature ran an article on later (1995) reports entitled "The principle of least astonishment" (316:230-234).

Re:Right turn, Clyde... magnepole-nastics

[CheshireCatCO]

Actually, if you pay closer attention, the third paper only says that they COULD be seeing a rapid shift. Not that they are. The authors themselves are pretty hesitant to claim what you're jumping on so readily.

And, as you note, most geophysicists don't think that those rocks are suggesting what you're accepting as fact. The problem with real science is that the data aren't always as clear cut as in the labs you do in classes.

Interestingly, this is the first time you've posted anything with substance. You're right, there is evidence there for a rapid reverse. Not *good* evidence, but evidence.

In any event, you're either jerking my chain or you're a raving lunatic. Either way, there's little point in continuing this.

Re:Right turn, Clyde... magnepole-nastics

[Anonymous Coward]

In any event, you're either jerking my chain or you're a raving lunatic. Either way, there's little point in continuing this.
It's worse: the guy's a "scientific" creationist who fancies himself a physicist. Now I knew /. has a good number of biologists and a couple of geologists around to quash creationist pseudoscience from those areas, but it's good to see that there's a few physicists and astronomers around to expose pseudoscience from their end as well.

Spun out on pseudoscience? (-:

[leonbrooks]

I enoyed your rant, but this one in particular amused me:

Uranus's spin and magnetic field axes are about 60 degrees apart. That's no where near alignment.

He [...] procedes to blame large amounts of cobalt and iron in Earth's crust for the slightly off spin axis magnetic field axis.

He forgets, of course, that as well as being magnetic, it's also heavy and enough of it to influence the magnetic field would produce an effect not unlike your car's harmonic balancer disintegrating.

I don't know whether people sited opposite these deposits would have much time to enjoy the lowered apparent gravity before Earth set about becoming an extremely large and dense set of rings around the Moon.

Based on the cratering record on the Moon, mainly, the calculated interval between mass exinction causing impacts is about 100 million years.

Yeah? Which part of the Moon did you have in mind? Poles? Maria? Farside? And how did you set about dating the craters? You used a number of WAGs, I'll bet. (-:

I had to reply to that nonsense theory.

Did you? Why? Serious question. I'm interested in seen how straight an answer you'll give.

Re:Spun out on pseudoscience? (-:

[CheshireCatCO]

"Yeah? Which part of the Moon did you have in mind? Poles? Maria? Farside?"

Um, the whole thing... the cratering rate appears to have been fairly constant over the past 3-4 billion or so years. Thanks to the fact that the Moon has areas of different ages, we can figure out the cratering rate. (You date those surfaces with those nifty rocks that the Apollo astronauts brought back.)

Thanks for asking, though. I suggest reading "THe New Solar System" next time *before* you assume that we're making stuff up.

"Did you? Why? Serious question. I'm interested in seen how straight an answer you'll give."

Because when crackpots like yourself are the only ones talking, people start to believe you. Sad, but true.

Serious question: why does my replying bother you?

Re:Spun out on pseudoscience? (-:

[leonbrooks]

the cratering rate appears to have been fairly constant over the past 3-4 billion or so years.

References? Comments on the delta between farside and nearside? Comments on ghost craters?

Serious question: why does my replying bother you?

It doesn't, I'm delighted by it. Seldom are people serious enough to make me think about my replies. Sad but true. Welcome to the elite.

However, I get the distinct impression that I'm pushing you near the edge of your resources sometimes. You're asking me for references and getting them but the best I've seen in return are whole books, and even those are basically popsci. For someone whose responses are so thinly supported (presumably because "everyone knows" - which is the core problem, dang it), you're too assertive. Too many throwaway lines, too much drama.

Cosmology lectures are all well and good, but count the references to actual data in them, and the references to actual data in those references, and you're getting pretty close to homeopathic doses of actual observation behind the whole structure you're supporting. This is almost tragic for science which is so well funded and supposedly mainstream.

The good is the enemy of the best.

Magnetic GPS?

[Anonymous Coward]

I'm intrigued. If animals can tell exactly where they are by sensing the magnetic field's "texture" [http://www.pbs.org/wgbh/nova/magnetic/animals.htm l], shouldn't GPS make use of that too? It seems to me that such technology would be a lot cheaper than sending sattelites to the orbit.

Re:Magnetic GPS?

[Colonel Angus]

I think that works for animals who are looking for general areas, or general "feelings". But if you are trying to pinpoint a location down to seconds, I doubt highly that a magnetic field which is constantly shifting and moving around would be of much use to GPS.

Re:Magnetic GPS?

[Anonymous Coward]

Agreed. It sounds a lot like the general "feelings" get them in the "neighborhood", but they're almost certainly not "flying blind" (or walking, or crawling) -- except in the case of bats, and even *they* have other senses than their "magnetic sense"...

Geniuses | Book on science

[leonbrooks]

But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses.

I suppose that, being SlashDot, it's a point that constantly needs to be made.

Go read a book on the scientific method.

Done. Now go and see how it works in real life. You're speaking to a bloke with four qualified scientists that he knows of in his family tree, and several more as friends.

Re:Geniuses | Book on science

[BerntB]

[I have read a book on the scientific method] Now go and see how it works in real life.

Maybe you have. But you wrote:

Tell me of any seriously revolutionary idea which you know was accepted with open arms by all.

Academics quarrels and questions everything. It's not only their personality but their jobs...

You can't find any idea about anything that was accepted by everyone.

Maybe you have read up on the math and the subjects you discuss enough to have a well developed opinion on why the researchers are wrong. I have enough with what I'm trying to do and learn to check. But the quote doesn't sound like you do.

Re:Geniuses | Book on science

[leonbrooks]

You can't find any idea about anything that was accepted by everyone.

Missing word: revolutionary.

As long as the new thing is close enough to safe orthodox dogma, it runs a fair risk of being wildly accepted by everyone who matters.

It's only as it tends towards truly useful in breaking the inevitable ossification that an idea (and by contamination its originators and supporters) starts getting daggers in its back.

Re:Geniuses | Book on science

[BerntB]

As long as the new thing is close enough to safe orthodox dogma, it runs a fair risk of being wildly accepted by everyone who matters.

Uhm, didn't you claim to know some academics? :-)

Yes, the old inside/outside of a paradigm discussion.

Generally, most new ideas fail -- no matter how smart the people that put them forward.

To apply a simple heuristic:
If you really understand everything better than anyone else you would be to busy to post to /.

I have nothing more to say here.

(-: If my heuristic fails and you get the Nobel prize -- put up a sign with an URL to my comment here... :-)

Re:Geniuses | Book on science

[TwistedGreen]

Let's try to minimize the fissure between emic and etic practices, okay? I see no reason to further accentuate them.

Go on, ignore the references ya coward! (-:

[leonbrooks]

In other words, you have nothing that you can put forth to show what you're talking about.

So says the man who has not read a word of the two references cited in the GP?

Go back and read them, then try again. Meanwhile...

we'd be all *over* something revolutationary and new

As long as:

• It wasn't too terrifyingly different (ie, not too different from our current worldview - or to put it differently, it has to be modestly "revolutationary and new");
  
• we thought we had a plausible answer to quench it with, or at least weren't more than a hairsbreadth away from figuring it out ourselves;
  
• we don't have to rework too much existing theory if we accept it

Without those qualifiers, your assertion is codswallop.

The Giant Impact model of the Moon's formation took hold quite quickly, too.

Pity it's still under heavy dispute then, isn't it? (-:

You might also want to think about a couple of decades in terms of "quickly accepted" and the difference between acceptance of a theory de novo when contrasted with the acceptance of a theory which has already been abuilding for years.

Maybe it's just me, but I rate the functionality of an idea far more highly than its peer acceptance rate.

usually you'll find a number of them quickly jumping into the new field. (That's how you make a name for youself, after all)

I call bullshit. That's how you get fired, or at least get a black mark on your research record which cripples your career.

The "heroes" adopt incremental improvements ahead of the pack. The vast majority of true pioneers, willing to avidly and openly explore genuinely revolutionary ideas, get pilloried for years, sometimes decades, and many die scorned only to have people come around to an understanding of what they were doing long after they're safely buried.

J Harlan Bretz, for example, was sidelined and scorned for forty years before his ideas were even investigated, and for the justification of hearing one of the investigators who was finally cajoled into actually taking a trip out to look at the Washington badlands for an actual look at the rocks exclaim "how could we have been so blind?"

His sin? Heresy. His theories, which are now mainstream and shatteringly obvious in hindsight, challenged the dominant orthodoxy in geology. They sailed too politically close to ideologically sensitive areas, to "political" boundaries which have absolutely nothing to do with science and everything to do with philosophical prejudice, and which still exist.

It's a brave and stubborn scientist who candidly investigates truly novel theories.

Now get off your ass and read, boy!

Re:Go on, ignore the references ya coward! (-:

[fluffy666]

Maybe it's just me, but I rate the functionality of an idea far more highly than its peer acceptance rate.

It is just you. Personally, I look for theories that are consistent with the evidence.

I call bullshit. That's how you get fired, or at least get a black mark on your research record which cripples your career.

I call prove it.

The vast majority of true pioneers, willing to avidly and openly explore genuinely revolutionary ideas, get pilloried for years, sometimes decades, and many die scorned only to have people come around to an understanding of what they were doing long after they're safely buried.

Nice use of the old False Dichotomy argument there. Apparently Newtonian gravity, the Periodic table, quantum physics, etc, etc. were not revolutions(!), but the discovery of a glacial lake dam burst was. Hmmm.

Geology is an especially good subject for this, swince although people have been studying geology in general (or gathering evidence), the basic framework was not really put in place until the 1970s with the development of plate tectonics. Accurate radiometric dating, micropalentology, stable isotope analysis and many other techniques are also pretty recent - yet often essential in proving or disproving old theories. In turn this means that old educated guesses can be proven or disproven. To point that out and then whine on about heresey is, quite frankly, just silly.

It's a brave and stubborn scientist who candidly investigates truly novel theories.

It's also a very brave scientist/person who can turn around and say 'I was wrong' when the evidence disproves their pet theory. Could you do that?

Dynamos, lightning, suspicions

[leonbrooks]

Well, it isn't linear, for one thing.

Neither is my car's alternator. But linear should be in the ballpark, and it's an order of magnitude off. And you haven't even spoken to my observations about the variety of compositions, temperatures and spins, and in particular to the complete absence of systematism amongst them.

Valles Marineris is way to big to be carved by lightening.

Cloud-to-ground lightning, I agree. (And by the way, Konqueror spellchecks within web forms starting from the version which comes with KDE 3.2, hint, hint). But how about body-to-body? What's the charge on a comet? What's the charge on a planetisimal the size of Pluto, and how many of them have wandered in past Mars so far? Something for the asteroid defense guys to consider. An event to watch from the comfort of something like Hubble, rather than on the ground.

On the other hand, while you causually dismiss erosion and tectonics, you probably should step up to the plate and explain the Grand Canyon on Earth (erosion-caused) and the Himilays (tectonics).

No worries. Remember that you asked for this, and that sacred cows make the tastiest barbeque. (-:

A bunch of the carving in the Canyon was done in perhaps a week or few with [RB Scarborough, Cenozoic Erosion & Sedimentation in Arizona, Arizona Bureau of Geology and Mineral Technology, 16 Nov 1984] a single or few rushes of water from a "fossil" lake or lakes with several times the size of Lake Missoula - of which mighty Lake Powell is a mere shadow and the beaches above it silent witnesses - in the Colorado Plateau area, which is possibly also responsible for the severely flat peneplane above it, and was followed up by a series of large flows (one pegged at "up to 15 million cfs"), which did a lot of the "slotting" which we observe today. The sudden removal of so much material (plus the water) may even have triggered uplifting in the area.

Slow and steady won't do it, and we've collectively known that for a long time [ED McKee, RF Wilson, WJ Breed, and CS Breed, "Evolution of the Colorado River in Arizona," Museum of Northern Arizona Bulletin 44 (1967), 1-67] and it's caused a fair bit of headscratching since [RJ Rice, "The Canyon Conundrum," Geographical Magazine 55, 1983, pg 291]. The Havasupai Indians even have a legend about it, although where they got it from is still an open question.

Have a look at the floods at Milford Lake, Coralville Lake, Burlingame Canyon, Providence Canyon and Tuttle Creek Reservoir [Archer, AW, J Kinser, SC Grant, JR Underwood, PC Twiss, RR West, KB Miller. 1993. Geology of the recently formed Grand Canyon of Manhattan. Department of Geology, Kansas State University, Manhattan] for much smaller but contemporary (and so better documented) examples of similar erosion. The prehistoric flooding of the Altay Mountains was also pretty spectacular, requiring water up to 1900m deep to produce the observed landforms [Baker, VR, G Benito, and AN Rudoy. 1993. Paleohydrology of late Pleistocene superflooding, Altay Mountains, Siberia. Science 259:348-350].

A thing to remember in connection with the origin of this discussion on Mars is that there's a good deal more obvious water available on Earth to do these things with, and none no Mars, nor an atmosphere which would support it, and there hasn't been for a very long time.

There are marine fossils right up near the top of Everest, a big hint that the many-miles-up peaks were once on a sea floor - or at least had sea floor dumped on them before they hardened - and haven't been subducted in between times.

And while you're at it, you can use your lightening "theory" to explain the Tharsis Bulge on Mars.

Why?

Have a careful look at VM. Flat bottom, steep sides, side-canyons crossi

Re:Dynamos, lightning, suspicions

[exp(pi*sqrt(163))]

Why have you spent so much time filling your brain with 'facts' that you don't actually understand (in some cases by your own admission)? Oh, I thought I'd also point out that someone else seems to have thought the same thing as me, hacked into your account, and placed an apposite quotation in your sig. I strongly recommend that you read it.

Challenged - and upheld

[leonbrooks]

You're right, there is evidence there for a rapid reverse. Not *good* evidence, but evidence.

Good evidence. It's been challenged, as you might expect, and reviewed and checked by the authors themselves in anticipation of this, and re-done in several different ways and the answers always come up smiling. Peer review has pounded on it, hard, and failed to break it.

In any event, you're either jerking my chain or you're a raving lunatic.

My turn to come off at a corner, I guess.

I present evidence, and the segue from that is that I'm either jerking your chain or a nutcase? Has the phrase "impossible to please" ever been used in your presence? What happens when I send you forty impeccable references, you call the cops? (-:

It does look like you're running out of depth, and know it, and are looking for an exit line. Well, good luck sitting on your conscience...

charge separation safety

[barakn]

He goes on to assert that charge seperation cannot occur (which is funny, since a child can do it in the lab with a peice of metal and a blowtorch held at one end) because we'd detect the powerful magnetic field from the electrostatics

I wouldn't let blow-torch-wielding children loose in my lab, but I'd certainly let them separate charge by rubbing their heads with balloons. Or let them pet my cat.

Re:charge separation safety

[CheshireCatCO]

Well, we frequently have to replace out Timmys in out labs, but we let the kids have blowtorches.

In this case, the thermal gradient is the cause of the charge seperation, just like is believed to happen in the Earth. There might be loads of cats and amber rods, but that's not well-supported in the seismology data.

No magnetic field?

[confused one]

Great! I need help with my tan...

Re:You sound as if you know what you're on about..

[exp(pi*sqrt(163))]

I know barely enough to clearly discern why big-bang is broken...

My current favourite is one which features a changing ZPE...

And what, pray tell, made it your favorite? The fact that it came packaged in a pretty box, the pleasant aroma that it gave off, or maybe just the fact that when you wear it it gives you warm fuzzies?

"Bad News" is neither Bad nor News

[Anonymous Coward]

Pedantic maybe.

This issue has been around for years and there is little evidence to say that the issue is a "bad" one.

Wow

[barakn]

You managed to stay on topic for only 20% of your rant. Sticking with magnetic fields for the moment.... Another poster has already pointed out quite reasonable explanations for the magnetic fields of the terrestrial planets. "It is quite clear that our current ideas about planetary magnetism are at best whistling in the dark" because we don't know enough about the interiors of the planets, not because of fundamental flaws in physics theories as you seem to imply. A recent model has explained the complex fields of Neptune and Uranus, relying on a thin convective region over a nonconvective fluid. It would thus be quite difficult to compare Venus and Uranus, as their internal structures are radically different.

Valles Marineris made by lightning?

[barakn]

Ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha .........

That's the stupidest thing I've ever heard. I'm not certain why you'd need a gigantinormous lightning bolt to explain loose rock on the surface of a planet which bears the scars of millions of impacts. And since planetary surfaces tend to act as equipotential surfaces, what sort of bizarro explanation do you have for a lightning bolt that travels horizontally for 4000 km? You claim that "water, sand and tectonics don't explain much" without one shred of evidence. Here's what the USGS has to say about the formation of the Valles Marineris:

"[F]irst the surface collapsed into a few deep depressions that later became filled with layered material, perhaps as lake deposits. Then graben-forming faults cut across some of the older troughs thus widening existing troughs, breaching barriers between troughs, and forming additional ones. At that time the interior deposits were locally bent and tilted, and perhaps water, if still present, spilled out and flowed toward the outflow channels. Huge landslides fell into the voids created by the new grabens. Wind-drifted material, mostly dark in color, apparently still moves along the canyon floor and locally forms conspicuous dunes."

I don't think this theory relies on tectonics per se. The surface collapse was merely due to the enormous weight of the nearby and recently extruded Tharsis bulge. But in the strange world of leonbrooks, the theory that requires the largest rewrite of physics is always the correct one.

Your ideas about the magnetic fields of planets are almost as wacko. Ignoring the fact that each planet's chemistry, structure, rotation, and history are unique and that dynamo theories are highly nonlinear, you insist that the noted variation in them can't be explained by dynamo theories and give no evidence.

How you'd set about reconciling a dynamo theory with the lesser gas giants is beyond me. John, if you do try to explain it (as many great men have tried to do in the past) please give me time to sell tickets.

Too late. Its already been done. Perhaps if you weren't wasting your time vainly trying to debunk all mainstream science, you'd have noticed.....

Re:You sound as if you know what you're on about..

[Ayaress]

One thing about Venus: I've never heard it say that retrograde spin is related to a lack of a magnetic field, but I have seen a simmilar suggestion: That it's unusually slow spin (243 days - although it's "day" is only 116 because it actually orbits faster than it rotates) doesn't stir up enough motion in its liquid core (if it has one, doesn't say anything on the page where I got the rotational speed) to produce a magnetic field.

Good reply, but...

[leonbrooks]

...if what you say about rotation and cooling is true and relevant, it should also apply to Mercury - and doesn't. True, I believe - relevant, less so.

The gas giant "reconciliation" is just a guess, not tested, not known to be workable. Considerably less definite than the actual measurements.

When I talk about lightning, I don't have atmospheric storms in mind. They don't have the energy density to do much, and it's not as if Mars has an atmosphere to brag about anyway.

However, if the discharge came from a near-miss by a highly charged comet or KBO or even planet, the scar would look pretty much as it does, random gougey bits starting in the west, picking up to a single (pair of) stream as enough debris flies up to provide really good conduction, a big splatch in the middle at closest approach where the discharge "sticks" at the shortest distance between two points, then more trench tailing off to the ever shallower random isletty-looking stuff to the east.

As to the always-forms-glass idea, I call bullshit. (-:

More examples? here (check out some of the secondary damage and think about what a few thousand cubic km of Mars rock would do under suitably scaled-up circumstances) here and many other places. Google is your friend.

The article is incomplete.

[Tukla]

The article neglects to explain how this is the fault of the Bush administration.

Don't worry!

[Anonymous Coward]

I'm using our Star Wars technology from the future to send this message back to your time. Don't worry, we're having no trouble at all working on the problems arising from the pole-shift. It's just that the radiation tends to interfere with our satellite communiASFE#%532gag#$S4 [NO CARRIER]