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08-08-2002, 07:22 PM | #1 | |
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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:
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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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. |
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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08-08-2002, 07:59 PM | #4 | |
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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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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:
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> |
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:
<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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08-09-2002, 02:30 PM | #7 |
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Thanks to THE LOST NUMBER.
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08-09-2002, 05:16 PM | #8 | |||||
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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:
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:
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08-09-2002, 07:06 PM | #9 | ||
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Quote:
In particular Humphreys is trying to "debunk" G. Brent Dalrymple who he quotes as saying: Quote:
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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08-10-2002, 06:45 AM | #10 | |
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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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