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Old 08-08-2002, 07:22 PM   #1
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Post Humphreys: Earth's Mag Field is Still Losing Energy

In the June 2002 CRSQ, the leading "journal" for the YECs, D. Russell Humphreys has an article.

<a href="http://www.creationresearch.org/crsq/articles/39/39_1/GeoMag.htm" target="_blank">The Earth’s Magnetic Field is Still Losing Energy</a>

Here is the abstract, click on the above for full text.

Quote:
This paper closes a loophole in the case for a young earth based on the loss of energy from various parts of the earth’s magnetic field. Using ambiguous 1967 data, evolutionists had claimed that energy gains in minor (“non-dipole”) parts compensate for the energy loss from the main (“dipole”) part. However, nobody seems to have checked that claim with newer, more accurate data. Using data from the International Geomagnetic Reference Field (IGRF) I show that from 1970 to 2000, the dipole part of the field steadily lost 235 ± 5 billion megajoules of energy, while the non-dipole part gained only 129 ± 8 billion megajoules. Over that 30-year period, the net loss of energy from all observable parts of the field was 1.41 ± 0.16 %. At that rate, the field would lose half its energy every 1465 ± 166 years. Combined with my 1990 theory explaining reversals of polarity during the Genesis Flood and intensity fluctuations after that, these new data support the creationist model: the field has rapidly and continuously lost energy ever since God created it about 6,000 years ago.
The take home message, according to him, is that the energy of the Earth's magnetic field (and not just the dipole component but total energy) is going down according the latest measurements. And at that rate the field would have been oh so strong a few thousand years ago a la the original argument by the late Thomas Barnes.

Some of the equations of the article are a bit beyond me but this seems to suffer from similiar problems that many YE arguments have. I really don't see any justification to extrapolate the trend that far back. Indeed his own Table II suggest that magnetic energy content went down from 1900 to 1930 then went up (way up in 1945 and 1950) and since the 1960s has gone steadly down. He would need to justify an exponential decay, etc. There is also the abuse of Coe, Prevot, and Camps' rapid reversal.

Any geologist/physics types want to take a hand at debunking?
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Old 08-08-2002, 07:32 PM   #2
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\if it's the same one I remember, you can see that it means bollocks by one of the diagrams that shows the field fluctuation over several centuries.

seeing as I think the first time we managed to measure the field was in the 1800's (accurately measure) the rest of the graph can be shown (from the info there) to be pure fanciful speculation.
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Old 08-08-2002, 07:39 PM   #3
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I seem to recall that millions of years of magnetic field reversals are recorded in the trans-atlantic ridge and corroborated via other dating methods. This has fatal consequences for Humphrey's theory, because even if it was totally correct in that the field is losing energy over thousands of years, it's been shown to gain it back over longer periods EVERY SINGLE TIME.
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Old 08-08-2002, 07:59 PM   #4
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Quote:
Originally posted by WinAce:
<strong>I seem to recall that millions of years of magnetic field reversals are recorded in the trans-atlantic ridge and corroborated via other dating methods. This has fatal consequences for Humphrey's theory, because even if it was totally correct in that the field is losing energy over thousands of years, it's been shown to gain it back over longer periods EVERY SINGLE TIME. </strong>

You are guilty of not reading what Humphrey wrote and indeed you did not read the abstract I quoted or my mention that he abused data for the rapid reversals. Unlike Barnes, Humphreys does have magnetic reversals indeed. You are going to have to go back to drawing board on that criticism since it is wrong since it does not actually a criticism of Barnes and not Humphreys.
And I think you are confusing polarity of the magnetic field with total energy of the magnetic field.
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Old 08-08-2002, 09:42 PM   #5
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Typical ignorant creationist rhetoric is what that link is about, as can be demonstrated by the following flaws in Humphreys blurb:

1.He ignores the fact that evidence for magnetic reversals most certainly cannot be explained by creationism. The rocks that reliable reversal deposits are found in, in addition to having their long ages confirmed by radiometric dating, are usually (though not always) igneous, often extending from the centers or near centers of some entire oceans and other very large bodies of water, onto the near shore. This is because of sea-floor spreading. For it to happen in far less than 6,000 years (it's orientation can be roughly pinned down even from historically ancient times) would require the physical impossibility of plates moving nightmarishly fast.

Instead of addressing this, Mr. Humphreys seems to think he can just invoke any absurd theory he wants to explain it (that absurd theory being whatever typically outrageous creationist hogwash "theory" he uses as an explanation - I'm not sure which one he favors). He can't. He has no explanation for how these things can happen rapidly (i.e. in 6,000 years or less, instead of millions). Further, he seems to think that "rapid" magnetic reversals--which are already known about by any good geologist--somehow "prove" that the Earth is young. In fact they far better fit mainstream geologic interpretations which state that, all things considered (something you can never do if you're a creationist), such changes cannot occur at anywhere near the level of rapidity which YECs claim. Remember: simply because the magnetic reversal itself happens rapidly does not mean the causes which lead up to it happening can occur rapidly.

2.He ignores the fact that magnetic reversals would, to some significant degree, be virtually certain to produce various strength differences in the fields that they create. This is simple, very basic science here: magnetic reversals aren't all the same length of time (ignoring his laughably intellectually bankrupt idea that they all happened within the last 6,000 years). Each one has fluctuated greatly, even if we reject radiometric dating and go only with sea-floor spreading measurements of age. They aren't perfect.

Can he not figure out that such a natural phenomenon is going to have fluctuations in the level of energy (strength) is has? If a river floodplain experiences flooding every few years, are all of them going to have the exact same energy output? Substitute "river floodplain" and "flooding" for lots of other phenomenon, like "volcano" and "eruption", "beach" and "hurricane", "flat plain" and "tornado", and so on. Really, on and on and on, with God only knows how many natural phenomenon - when similar ones occur in repetition, they virtually always have different energy outputs, that "decay" (so to speak) after the initial event has happened. This alone would logically dictate that, since the field has reversed itself numerous times, it's overall level of energy has increased and decreased, too. In other words; if energy levels have fluctuated to great highs and lows in respective direct relation to the most powerful event of the phenomenon and subsequent subsidence of activity in said phenomenon, what makes it so implausible that we, being so long away from the last magnetic reversal, are experiencing a "low" point in it? Come on now; what plausible mechanism is going to cause an entire shift in the earth's magnetic field without being able to somehow add energy to it specifically!?! What intelligent thing does he have to say about this? Nothing, that's what. He just ignores it or gives some pure B.S. excuse. And this is very basic science and logic which he doesn't comprehend or won't pay attention to. If he can't grasp that, how can you trust him to do so with other issues that are often far more complex?

3.He either is too ignorant to figure out or too dishonest to report that past fields have been analyzed through the evidence they left, and it turns out that their various levels of strength really did fluctuate! Here is a quote from him:
  • "According to my geomagnetic model, whose general features agree with paleomagnetic and archeomagnetic data, the total field energy has always decreased at least at today’s rate, and it will continue to do so in to the future )."

This is a bona fide, flat out, 100 percent, bold faced false claim. To be fair, I won't call it a complete lie, since he may have just been ignorant. But astonishingly so if he was - though not exactly being announced in every archeology and geology book in the world, a trained scientist like Humphreys who researches something like this should be easily able to discover the fact that both archeomagnetic and paleomagnetic data demonstrate field strenghts have fluctuated. Yes, not just their orientation, but the literal strength of them, too. This alone refutes his entire thesis that they can't, in addition to proving that he has a lot of work to do in sharpening his information gathering skills.

4.He fails to truly comprehend the significance of just what causes the magnetic field, which means his views of it's actions then become a mess. As I said before; the processes which lead to this aren't rapid compared to the human lifespan. Fluctuations in the vicious, large, thick molten and semi-molten sections of the earth are responsible, and it is physically impossible for them to consistently and constantly produce many large scale changes (such as reversals) within a small length of time such as the human lifespan.

[ August 09, 2002: Message edited by: The Lost Number ]</p>
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Old 08-09-2002, 01:18 PM   #6
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This is more physics than I grok, and maybe I'm misunderstanding something, but at a glance it would appear quite easy to refute Humphrey's argument, because the past intensity the geomagnetic field (GMF) can be deduced from the geologic record.

I'm reading some papers along these lines as part of my latest project on terrestrial cosmogenic nuclide exposure dating, because variations in the GMF strength produce variations in the production rates of various cosmogenic nuclides. The production rate of these nuclides varies inversely with the GMF intensity, except near the poles, where the GMF lines of force are basically vertical.

There are several methods being used to reconstruct a history of the intensity of the GMF over time. When these records of paleo-intensity are combined (as has been done for the past 220Ka), it produces a curve with many peaks and valleys, not just a decline from a high initial value. The GMF is currently declining from a maximum reached about 3ka (IIRC). But between 40ka and 3Ka, for instance, the intensity of the GMF actually intensified from approximately 3 to 10 x 10^22Am^2. The current value is about ~8 x 10^22Am^2. The link below shows the Sint 200 paleo-intensity curve for the last 200Ka. From

Quote:
Guyodo and Valet, 1996. Relative variations in geomagnetic intensity from sedimentary records: the past 200 thousand years. Earth Planetary Science Letters 143, p. 23
For another example os the same type of research, see:

<a href="http://cgrg.geog.uvic.ca/abstracts/StonerGeomagneticPiston.html" target="_blank">Geomagnetic paleointensity and environmental record from Labrador Sea core MD95-2024: global marine sediment and ice core chronostratigraphy for the last 110 kyr.</a>


<a href="http://www.geo.ukans.edu/tcnweb/figures/f3-7.htm" target="_blank">http://www.geo.ukans.edu/tcnweb/figures/f3-7.htm</a>

Another way to reconstruct a history of GMF intensity is to use 10Be. 10Be is a cosmogenic nuclide formed in the atmosphere (and in rocks) by nuclear interactions with cosmic radiation. The production rate is strongly modulated by the GMF field strength, such that production is inversely related to GMF strength. Thus, 10Be profiles preserved in oceanic sedimetns and ice cores can be used to reconstruct GMF intensity over time. This has been done for the Vostok ice cores, for example.

I'll get a few papers on this tommorrow when I go to the library.

Patrick

[ August 09, 2002: Message edited by: ps418 ]

[ August 09, 2002: Message edited by: ps418 ]</p>
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Old 08-09-2002, 02:30 PM   #7
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Thanks to THE LOST NUMBER.
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Old 08-09-2002, 05:16 PM   #8
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Quote:
Originally posted by LordValentine:
<strong>You are going to have to go back to drawing board on that criticism since it is wrong since it does not actually a criticism of Barnes and not Humphreys.</strong>
Actually it is, if you interpret what WinAce said charitably. True, Humphrey 'accepts' the reality of polarity reversals. But WinAce also said that "even if it was totally correct in that the field is losing energy. . . it's been shown to gain it back over longer periods." If he means to say that the field strength has been shown to fluctuate over time, than this both correct and a valid criticism of Humphrey's 'model,' because Humphrey's model 'predicts' a simple, long term decline in the field strength.


Patrick

PS - Here are some relevant abstracts I found on paleointensity. Apparently the field strength has been constructed much further back than 200Ka, as I stated in my last post. Note also that in the latter two papers, paleointensities are estimated from Proterozoic and Archaen rocks, which would definiately be 'preflood.' Yet the GMF intensity at the time these rocks were formed is estimated to have been comparable to the present day.

M.T. Juarez and L. Tauxe, The intensity of the time-averaged geomagnetic field: the last 5 Myr, Earth and Planetary Science Letters 175 (3-4) (2000) pp. 169-180

Quote:
The existing database for paleointensity estimates of the ancient geomagnetic field contains more than 1500 data points collected through decades of effort. Despite the huge amount of work put into obtaining these data, there remains a strong bias in the age and global distribution of the data toward very young results from a few locations. Also, few of the data meet strict criteria for reliability and most are of unknown quality. In order to improve the age and spatial distribution of the paleointensity database, we have carried out paleointensity experiments on submarine basaltic glasses from a number of DSDP sites. Of particular interest are the sites that provide paleointensity data spanning the time period 0.3¯5 Ma, a time of relatively few high quality published data points. Our new data are concordant with contemporaneous data from the published literature that meet minimum acceptance criteria, and the combined data set yields an average dipole moment of 5.49±2.36×1022 Am2. This average value is comparable to the average paleofield for the period 5¯160 Ma (4.2±2.3×1022 Am2) [T. Juarez, L. Tauxe, J.S. Gee and T. Pick (1998) Nature 394, 878¯881] and is substantially less than the value of approximately 8×1022 Am2 often quoted for the last 5 Myr (e.g. [McFadden and McElhinny (1982) J. Geomagn. Geoelectr. 34, 163¯189; A.T. Goguitchaichvili, M. Prévot and P. Camps (1999) Earth Planet. Sci. Lett. 167, 15¯34]).

Jacques Brassart, Emmanuel Tric, Jean-Pierre Valet and E. Herrero-Bervera Absolute paleointensity between 60 and 400 ka from the Kohala Mountain (Hawaii) Earth and Planetary Science Letters, 148 (1-2) (1997) pp. 141-156.

Quote:
Magnetic experiments including thermal demagnetization of the natural remanent magnetization (NRM), mineralogical studies and paleointensity measurements have been conducted on ten lava flows, with ages between 60 ka and 400 ka, from the Kohala Mountain, Hawaii. Of the samples, 62 were subjected to double heating paleointensity experiments under vacuum. In total, 35% of the specimens did not exhibit significant magnetomineralogical changes during heating and met all the criteria for successful determinations of absolute paleointensity. A technique of corrections was attempted for samples that exhibited changes in their ability to acquire partial thermoremanent magnetization (pTRM) during heating but did not show acquisition of chemical remanence (CRM). This procedure doubled the rate of success, with consistent results between the uncorrected and the corrected data from within the same flows. The successful paleointensity estimates obtained for 8 lava flows are found to be in good agreement with previous absolute paleointensities obtained from other areas. The results are also consistent with the synthetic curve (Sint-200) of relative paleointensity obtained for the past 200,000 years from deep-sea sediment cores. There is thus no reason to infer the presence of large non-dipole fields in the vicinity of Hawaii. Overall, the geomagnetic intensity appears to have the same variability for at least the past 200 ka.
Ikuro Sumita, Tadahiro Hatakeyama, Arata Yoshihara and Yozo Hamano, Paleomagnetism of late Archean rocks of Hamersley basin, Western Australia and the paleointensity at early Proterozoic, Physics of the Earth and Planetary Interiors 128 (1-4) (2001) pp. 223-241

Quote:
We report the results of paleomagnetic and rock magnetic measurements of late Archean rocks from Hamersley basin, Western Australia, and the paleointensity determination for early Proterozoic. Basalts and banded iron formations have two to four components of remanent magnetization, and have consistent directions for different localities, indicative of geomagnetic origin. Rock magnetic measurements of basalts reveal that the main magnetic mineral is a fine-grained magnetite present in ~10 ppm in mass, which do not alter when heated up to its blocking temperature. We interpret the stable component up to ~390 °C as the post-tilting thermal overprint from uplift at 2.0 Ga, and the higher temperature component as the pre-tilting thermoviscous remanence during burial metamorphism. From the Thellier type paleointensity experiments using the thermal overprint component, we obtain a mean virtual dipole moment (VDM) estimate of (1.8¯3.6)×1022 A m2. This suggests that early Proterozoic was characterized by a 1 weak geomagnetic field of less than one-half of the present.
Arata Yoshihara and Yozo Hamano, Intensity of the Earth's magnetic field in late Archean obtained from diabase dikes of the Slave Province, Canada, Physics of the Earth and Planetary Interiors 117 (1-4) (2000) pp. 295-307

Quote:
The geomagnetic field intensity in Late Archean times is evaluated from Archean diabase dikes intruded into the Yellowknife greenstone belt of the Slave Province, N.W.T., Canada. The dike set used is referred to as the 8a dikes, and their age is bracketed between 2620 and 2642 Ma by crosscutting relationships between the 8a dikes and adjacent granitic rocks dated by U¯Pb method. Paleomagnetic directional data after thermal demagnetization (ThD) and results of some field tests suggest that the characteristic remanent magnetizations (ChRM) of the dikes have been acquired at ca. 2.6 Ga. Several rock magnetic studies indicate that the dike samples are suitable for paleointensity determinations. Thelliers' method with consistency checks was used for the paleointensity determinations, and two of the 8a dikes yielded the mean paleointensities of 30.9±1.1 and 43.9±1.2 T, respectively. The corresponding virtual dipole moments (VDM) of (6.3±0.2)×1022 A m2 and (9.0±0.2)×1022 A m2 are similar to the present day value, suggesting that, in the Earth's core, the dynamo process of comparable activity to that of the present day has already existed at ca. 2.6 Ga.
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Old 08-09-2002, 07:06 PM   #9
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Quote:
Posted by ps418:
<strong>Actually it is, if you interpret what WinAce said charitably. True, Humphrey 'accepts' the reality of polarity reversals. But WinAce also said that "even if it was totally correct in that the field is losing energy. . . it's been shown to gain it back over longer periods." If he means to say that the field strength has been shown to fluctuate over time, than this both correct and a valid criticism of Humphrey's 'model,' because Humphrey's model 'predicts' a simple, long term decline in the field strength. </strong>
Clarification? When you are talking about field strength are you refering to the dipole field (which obviously decreases to pretty much nothing during the reversal of polarity and was what Barnes was talking about) or the dipole component plus non-dipole component (which is what Humphreys is making his claim on). This is of very vital importantance. Barnes (who of course was the originator of the decaying magnetic field claim) plotted an alleged decay of the dipole component of the magnetic field.

In particular Humphreys is trying to "debunk" G. Brent Dalrymple who he quotes as saying:

Quote:
The same observatory measurements that show the dipole moment has decreased since 1820 also show that this decrease has been almost completely balanced by a corresponding increase in strength of the nondipole field, so that the stregth of the total observed field has remained about constant.
The thrust of Humphreys' article is that detailed measurements afterwards have disproven what Dalrymple stated and that the total magnetic field (dipole plus all harmonics) shows that the total magnetic field is not constant as Dalrymple claimed but is decreasing (1.41%+/-0.16% in 30 years). (Claims of what Dalrymple stated are as according to Humphreys; I have not checked Dalrymple directly so there might be context problems.)

I want to make sure that we are not really debunking the old claims of Barnes and instead are properly aimed at the claims that Humphreys is making in the here-and-now.
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Old 08-10-2002, 06:45 AM   #10
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Quote:
LordV: When you are talking about field strength are you refering to the dipole field (which obviously decreases to pretty much nothing during the reversal of polarity and was what Barnes was talking about) or the dipole component plus non-dipole component (which is what Humphreys is making his claim on).
I'll be in a better position to clarify this in a few days when I can go to the library, but at the risk of getting it wrong I'll go ahead and answer.

As I understand it, the strength of the whole magnetic field (dipole + nondipole components) does in fact change over time, and does not remain constant. This doesn't necessarily contradict what Dalrymple said, which was simply that the decline in the dipole component since 1820 has been "almost completely balanced" by an increase in strength of the nondipole field, and that the field strength has remained "about constant.". In other words, the total field is declining in strength, but not as fast as one would assume if one assumed a dipole field only.

The paleointensity data I referred to are evidence of the intensity of the field at a given time and place. If the overall field strength has been "rapidly and continuously" losing energy ever since God created it 6Ka, then this trend should be very apparent in the paleointensity data, but it isn't. For instance, the precambrian rocks cited above preserve evidence of a geomagnetic field no stronger than today's field.

So, again, although the field strength really does change over time, and really is declining right now, it was increasing in the past, the process can not "date" anything.

Patrick

[ August 10, 2002: Message edited by: ps418 ]</p>
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